RECORD OF DECISION Maunabo Groundwater ...Contamination Site (the “Site”), located in the...

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION 2

RECORD OF DECISION Maunabo Groundwater Contamination Site Maunabo, Puerto Rico SEPTEMBER 2012

R2-0002554

i

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 2 PART I - THE DECLARATION RECORD OF DECISION MAUNABO GROUNDWATER CONTAMINATION SITE MAUNABO, PUERTO RICO

R2-0002555

ii

DECLARATION FOR THE RECORD OF DECISION SITE NAME AND LOCATION Maunabo Groundwater Contamination Site Maunabo, Puerto Rico STATEMENT OF BASIS AND PURPOSE This decision document presents the selected remedial action for the Maunabo Groundwater Contamination Site (the “Site”), located in the Municipality of Maunabo, Puerto Rico, which was chosen in accordance with the requirements of the Comprehensive Environmental Response, Compensation and Liability Act of 1980 (“CERCLA”), 42 U.S.C. § 9601-9675, as amended, and to the extent practicable the National Oil and Hazardous Substances Pollution Contingency Plan (“NCP”), 40 C.F.R. Part 300. This decision document explains the factual and legal basis for selecting the remedy for the Site. This decision is based on the Administrative Record file for this Site. Refer to Appendix I of Part II – Decision Summary for copy of the Administrative Record Index for this Site. The Puerto Rico Environmental Quality Board (“EQB”) concurs with the selected remedy. Refer to Appendix II of Part II – Decision Summary for copy of the letter. ASSESSMENT OF SITE The United States Environmental Protection Agency (“EPA”), in consultation with EQB, has determined that site-related groundwater data contamination is limited and does pose a significant threat to human health or the environment; therefore, remediation is necessary. This determination is based on the conclusions of the Remedial Investigation (“RI”), Human Health Risk Assessment (“HHRA”), and the Screening Level Ecological Risk Assessment report, which indicated that tetrachloroethene, cis‐1,2‐dichloroethene, and 1,1‐dichloroethene exceeded the preliminary remediation goals for groundwater at the Site. The HHRA indicates that the levels of tetrachloroethene, cis‐1,2‐dichloroethene, and 1,1‐dichloroethene present in the groundwater at the Site exceed the acceptable risk range and thus presents an unacceptable risk. The selected remedy complies with Federal and Commonwealth requirements that are legally applicable or relevant and appropriate requirement (“ARAR”) to the remedial action and is cost effective. As such, the selected remedy for groundwater is protective of human health and the environment from actual or threatened releases of hazardous substances into the environment.

R2-0002556

iii

DESCRIPTION OF THE SELECTED REMEDY

The selected remedy for the Site consists of an air sparging/soil vapor extraction (for a cis-2,2-DCE plume) and monitored natural attenuation (for PCE and 1,1-DCE plumes). The selected remedy will achieve the remedial action objectives (“RAOs”) established for the Site by reducing the groundwater contamination to the established preliminary remediation goals (“PRGs”) and in accordance with the statutory determinations. The selected remedy includes the following major components:

• Pre‐design monitored natural attenuation (“MNA”) investigation • Air sparging pilot study • Remedial design • Air sparging/soil vapor extraction (“SVE”) system • Institutional controls • Long‐term monitoring • Five-year reviews

Pre‐Design MNA Investigation To address the uncertainty surrounding contaminant concentration reduction via MNA, an MNA investigation is required in order to provide information to better project the effectiveness of natural attenuation mechanisms at field scale and to confirm that active degradation of contaminants is occurring where needed. The investigation will incorporate extensive monitoring within, at the boundaries, and downgradient of the capture zones. The pre-design MNA investigation would be conducted for a sufficient period to observe meaningful trends (i.e., several years) decision points, and contingency plans would be included so that any unexpected increase in contaminant concentrations or off‐site migration of contamination can be quickly addressed. The key to the effectiveness of MNA is the ability of natural processes to reduce contaminant concentrations to acceptable levels in a reasonable time frame. Factors that may limit the applicability and effectiveness of the process include the need to collect data, the need for highly skilled data evaluators, and limiting natural attenuation to low risk situations. Air Sparging/SVE System Pilot Study A pilot test will be performed to determine the radius of influence of each sparge location and soil vapor extraction well, and consequently the number of sparge points needed. The pilot test will also evaluate the need for treatment of the collected vapors. Remedial Design Data obtained during the RI, pre‐design MNA investigation, and air sparging/SVE system pilot study would be used to develop the detailed approach for Site remediation during the design. All aspects necessary for implementing the remedial action would be considered, including, but not limited to, detailed layout of the treatment strategy and system, construction sequence, regulatory requirements, and cost estimates. It is anticipated that the sparge points will have a 10‐foot radius of influence and the SVE system wells will have a 20‐foot radius of influence.

R2-0002557

iv

Air Sparging/SVE System Installation/Operation The air sparge curtain would be installed upgradient of Maunabo #1, and a grid of sparge points would be installed in the upgradient portion of the cis‐1,2‐DCE plume. SVE system wells would be installed to collect sparged vapors in the vadose zone. There would likely be no need to treat the vapor prior to release to the atmosphere because discharge rates could be lower than Puerto Rico standards; however, the need for vapor treatment should be evaluated thoroughly during remedial design. We estimated that the sparge grid would be operated for one year and the sparge curtain for three years. Performance monitoring would be conducted at groundwater monitoring wells installed in the sparge grid as well as upgradient and downgradient of the sparge curtain. Institutional Controls The remedy will also involve implementation of institutional controls to control, limit, and monitor activities on‐site. The objectives of institutional controls are to prevent prolonged exposure to contaminant concentrations, control future development, and prevent the installation of wells within the contaminated plume boundary. The effectiveness of selected institutional controls will depend on their continued implementation. The types of institutional controls employed in the plume footprint would include activity and use restrictions enacted through proprietary (e.g., easements, covenants) and/or governmental (e.g., zoning requirements) controls to prevent use of the properties that would pose an unacceptable risk to receptors (i.e., for residential use). Other institutional controls could include restrictions on installation of drinking water or irrigation wells, restrictions on groundwater use at locations within the plume footprint, and restrictions on home or building construction within the plume footprint. Institutional controls (e.g., warning signs, advisories, additional public education, deed notices, notices of environmental contamination) may also be employed to limit access to contaminated groundwater. Long‐Term Monitoring Monitoring is an essential component of engineered air sparging/SVE system design and operation. Post‐construction long‐term monitoring is critical to ensure that the sparge curtain and grid are removing contaminants from the groundwater plume as planned. Since contaminants would remain on-Site, a long‐term groundwater monitoring program would be instituted to monitor groundwater contaminant concentrations and movement on-Site. Groundwater samples from the monitoring well network would be collected annually and analyzed for contaminants of potential concern. The monitoring data would be evaluated and used to assess the effectiveness of the remedy and to plan for further remedial action if required. Five‐Year Reviews Five‐year reviews will be conducted every five years using data obtained from the maintenance and monitoring program. These reviews are important under this alternative because it is an additional mechanism to ensure the protection of human health and the environment. In the Feasibility Study (“FS”), it was assumed that these reviews will be conducted six times for the duration of the 30 year FS evaluation period.

R2-0002558

Estimated Outcomes of Selected Remedy The principal outcome of the selected remedy is the restoration of the groundwater to the established PRGs, resulting in an improvement in the potable water supply for over 14,000 residents in the municipality ofMaunabo.

EPA Region 2 Clean and Green Policy Consistent with EPA Region's 2 "Clean and Green" Policy, the utilization of applicable green remediation practices would be considered and, to the extent practical, incorporated into the detailed design of the selected remedy. Some examples of the operational practices that would be applicable are those that reduce emissions of air pollutants, minimize water consumption, incorporate native vegetation into revegetation plans, and consider beneficial reuse and/or recycling of materials, among others.

STATUTORY DETERMINATIONS

As required under Section 121 of CERCLA, remedial actions carried out under Section 1 04 or secured under Section 106 must be protective of human health and the environment and attain the levels or standards of control for hazardous substances, pollutants, or contaminants specified by the ARARs of Federal environmental laws and Commonwealth environmental and facility siting laws, unless waivers are obtained. The selected remedy also must be cost-effective and utilize permanent solutions and alternatives treatment technologies or resource recovery technologies to the maximum extent practicable. Finally, the statute includes a preference for remedies that employ treatment that permanently and significantly reduces the volume, toxicity, or mobility of hazardous substances, as available.

CERTIFICATION

This decision document includes all the elements required to support the selected remedy in accordance with the Guide to Preparing Superfund Proposed Plans, Records of Decision, and Other Remedy Selection Decision Documents [EPA 540-R-98-031 OSWER 9200.1-23P (July 1999)].

AUTHORIZING SIGNATURE

In accordance with the requirements ofCERCLA and to the extent practicable, the NCP, EPA, in consultaf with EQB, has determined that the selected remedy for the Maunabo Groundwater Conta m ion Site is required in order to protect human health and the environment.

Walter E. Mugdan, Dir tor Emergency and Remedial Response Division EPA - Region 2

v

R2-0002559

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 2

PART II – DECISION SUMMARY

RECORD OF DECISION MAUNABO GROUNDWATER CONTAMINATION SITE

MAUNABO, PUERTO RICO

R2-0002560

Table of Contents

SITE NAME, LOCATION, AND DESCRIPTION ............................................................ 4

SITE HISTORY .................................................................................................................. 4

COMMUNITY PARTICIPATION .................................................................................... 9

SCOPE AND ROLE OF ACTION ................................................................................... 1 0

SITE CHARACTERISTICS ............................................................................................. 1 0

Conceptual Site Models ................................................................................................... 10

Site Overview .................................................................................................................. 13

Regional Geology ........................................................................................................ 13

Regional Hydrogeology ............................................................................................... 14

Site-Specific Geology .................................................................................................. 14

Site-Specific Hydrogeology ......................................................................................... 15

Cultural Resources ....................................................................................................... 16

Sampling Strategy ............................................................................................................ 16

Sources of Contamination ................................................................................................ 17

Types of Contaminants and Migration ............................................................................. 17

Current and Potential Future Land and Water Uses .......................................................... 19

Land Uses .................................................................................................................... 19

Groundwater and Surface Uses .................................................................................... 19

SUMMARY OF SITE RISKS ........................................................................................... 19

Summary ofHHRA ......................................................................................................... 19

Non-Carcinogenic Health Hazards ............................................................................... 20

Carcinogenic Risk ........................................................................................................ 22

Summary ofSLERA ................................................................................................ ,. ....... 23

REMEDIAL ACTION OBJECTIVES ............................................................................. 24

PRGs for the Site ............................................................................................................. 25

DESCRIPTION OF THE ALTERNATIVES .................................................................. 25

Remedial Alternatives ...................................................................................................... 25

Alternative 1: No Action ........................................................................................... 25

Alternative 2: Monitored Natural Attenuation ("MNA") ............................................ 26

Alternative 3: Air Sparging/Soil Vapor Extrusion (for the cis-2,2-DCE plume) and Monitored Natural Attenuation (for the PCE and 1,1-DCE plumes) ............................. 26

Alternative 4: In-situ Bioremediation (for the cis-1,2-DCE plume) and Monitored Natural Attenuation (for the PCE and 1,1-DCE plumes) ............................................... 27

R2-0002561

COMPARATIVE ANALYSIS OF ALTERNATIVES .................................................... 28

Overall Protection ofHuman Health and the Environment.. ............................................. 28

Compliance with Applicable or Relevant and Appropriate Requirements ("ARARs") ...... 29

Long-Term Effectiveness and Permanence ................................................................... 29

Reduction ofToxicity, Mobility, or Volume Through Treatment ................................. 29

Short-Term Effectiveness ............................................................................................. 30

lmplementability .......................................................................................................... 30

Cost ............................................................................................................................. 30

State/Support Agency Acceptance ............................................................................... 30

Community Acceptance ............................................................................................... 30

PRINCIPAL THREAT WASTES .................................................................................... 31

SELECTED REMEDY ..................................................................................................... 31

Estimated Outcomes of Selected Remedy ........................................................................ 33

EPA Region 2 Clean and Green Policy ............................................................................ 33

STATUTORY DETERMINATIONS ............................................................................... 33

Protection ofHuman Health and the Environment ........................................................... 33

Compliance with ARARs ................................................................................................. 34

Cost Effectiveness ........................................................................................................... 3 7

Utilization of Permanent Solutions and Alternative Treatment Technologies to the Maximum Extent Practicable ........................................................................................... 3 7

Preference for Treatment as a Principal Element.. ............................................................ 38

Five Year Review Requirements ...................................................................................... 38

DOCUMENTATION OF SIGNIFICANT CHANGES FROM PREFERRED ALTERNATIVE OF PROPOSED PLAN ........................................................................ 38

APPENDIX I ...................................................................................................................... 39

Administrative Record Index for Maunabo Groundwater Contamination Superfund Site .39

APPENDIX II ......................................................................... ........................................... 40

Puerto Rico Environmental Quality Board's Concurrence Letter ...................................... 40

APPENDIX III ................................................................................................................... 41

Figures ............................................................................................................................. 41

Figure 1- Site Location ............................................................................................... 42

Figure 2- Locations of the Plumes .............................................................................. 43

Figure 3- Groundwater Screening Investigation Sampling Locations (Transects) ........ 44

Figure 4 -Air Sparging/Soil Vapor Extraction System -Conceptual Model ................ .45

APPENDIX IV ................................................................................................................... 46

Proposed Plan and Fact Sheet (Spanish) .......................................................................... .46

2

R2-0002562

APPENDIX V .................................................................................................................... 47

Public Notices .................................................................................................................. 47

APPENDIX VI ................................................................................................................... 48

Public Meeting Attendance Sheet .................................................................................... 48

APPENDIX VII ................................................................................................................. 49

Transcript of the Public Meeting and Written Comments ................................................ .49

3

R2-0002563

SITE NAME, LOCATION, AND DESCRIPTION

The Maunabo Groundwater Contamination Superfund Site (the "Site"), EPA ID: PRN000205831, is located in Maunabo, Puerto Rico (Figure 1). This is a federal fund-lead site at which the U.S. Environmental Protection Agency ("EPA") is the lead agency, and the Puerto Rico Environmental Quality Board ("EQB") is the support agency.

The Site consists of three groundwater plumes (Figure 2):

Cis-1,2-dichloroethene ("cis-1,2-DCE'') Plume: The configuration of this plume indicates that a release of site-related contaminants, most likely tetrachloroethene ("PCE") or trichloroethene ("TCE"), occurred in or near the building housing the Puerto Rico Beverage ("PRB") facility. The plume is migrating toward the southwest, influenced by pumping at the Maunabo # 1 and groundwater flow toward the Maunabo River. The plume is well delineated to the southeast and to the northwest.

PCE Plume: The primary contaminant in this plume is PCE. The plume is migrating toward the northeast, influenced by pumping at the Maunabo # 1 and groundwater flow toward the Maunabo River. The downgradient edge of the plume is the Maunabo well # 1. This plume is located in the Former Sugar Mill ("FMS") area.

1,1-dichloroethene (1,1-DCE) Plume: This plume is located northwest of Maunabo #4 and differs from the PCE and cis-1,2-DCE plumes in that it consists almost entirely of 1,1-DCE.

SITE HISTORY

The Maunabo urbana public water supply system consists of four groundwater wells, referred to herein as Maunabo #1 through Maunabo #4. This system serves a population of approximately 14,000 people and is managed by the Puerto Rico Aqueduct and Sewer Authority ("PRASA").

In 1961, PRASA installed Maunabo #1 which was used until 1974. In 2001, PRASA placed the Maunabo #1 back into service. PRASA collected groundwater samples in 2002 at the four wells. Since March 2002, groundwater samples collected from Maunabo #1 has indicated the presence of PCE, TCE, and cis-1,2 -DCE. The maximum concentrations of PCE, TCE, and cis-1 ,2-DCE detected in Maunabo # 1 from 2002 to 2004 were 16.4 micrograms per liter ("f.lg/L"), 1.6 f.lg/L, and 4.3 f.lg/L, respectively. The federal maximum contaminant level ("MCL") for PCE and TCE is 5 f..Lg/L, and for cis-1,2-DCE it is 70 f.lg/L. Another chlorinated solvent, 1,1 -DCE was detected intermittently in Maunabo #1. The MCL for 1,1-DCE is 7 f.lg/L. Samples collected from the Maunabo #2, # 3, and #4 over the same time period indicated that chlorinated solvents were generally not present in these wells. Tap water samples of the distributed water revealed that the contaminants detected in Maunabo #1 were present in the drinking water system at various times.

In March 2002, the Puerto Rico Department of Health ("PRDOH") ordered PRASA to close Maunabo #1 because the PCE concentration exceeded the MCL threshold (5f.lg/L). However, rather than close the well, PRASA opted to treat the groundwater at the wellhead using

4

R2-0002564

activated carbon filtration tanks. Since then, the detections of PCE in raw groundwater samples from Maunabo # 1 have exceeded the MCL for PCE. Post-treatment samples, including tap water samples collected from the distribution system down the line from Maunabo #1, indicated that PRASA's treatment was not always effective and that contaminated drinking water was reaching the consumers.

In October 2005, EPA's Site Assessment Team 2 collected groundwater samples from Maunabo #1, #2, #3, #4 and the Maunabo PRASA distribution water system. The samples were analyzed for Target Compound List ("TCL") organic parameters, base/neutral/acid, pesticides/polychlorinated biphenyls ("PCBs") and Target Analyte List inorganic parameters including mercury and cyanide through the EPA Contract Laboratory Program ("CLP").

The data confirmed the presence of PCE and cis-1,2-DCE in Maunabo #1 and in post-treatment samples along the distribution line at levels below the MCLs. The results also confirmed the presence of 1,1-DCE in Maunabo #4 and a gasoline additive, methyltertbutylether ("MTBE"), in Maunabo # 1 and in the samples from the distribution water system. No detections were above the MCL, except for bis(2-ethylhexyl) phthalate (6.5 J.Lg/L) in Maunabo #3, which marginally exceeded the MCL of 6 J.Lg/L. PCE; cis-1,2-DCE; 1,1-DCE; and MTBE were not detected in Maunabo #2 and Maunabo #3.

In December 2005, EPA conducted a limited investigation to identify possible sources of groundwater contamination in Maunabo. Facilities that were investigated included the former Maunabo Municipal Solid Waste Landfill ("Maunabo Landfill"), PRASA's Wastewater Treatment Plant located close to Maunabo #1, El Negro Auto Body/Parts shop, Total Gas Station, Esso Gas Station, Maunabo Dry Cleaners, and five light industrial facilities operating under the auspices of the Puerto Rico Industrial Development Corporation ("PRIDCO"). The five identified PRIDCO industrial facilities were: Centro de Acopio Manufacturing ("CAM"); Juan Orozco Limited, Inc; PRB; Federal Emergency Management Agency ("FEMA") Storage Facility; and Plastic Home Products ("PHP").

A summary of the limited investigation activities and preliminary findings is presented below. All of the samples collected at the properties described below were analyzed for TCL volatile organic compounds ("VOCs") through the EPA CLP.

• Maunabo Landfill- EPA collected four surface soil samples, including one duplicate, one subsurface soil sample, and one groundwater sample at the former Maunabo Landfill. Since VOCs were not detected in the samples, no Preliminary Assessment/Site Inspection ("P A/SI") report was prepared for the Landfill.

• PRASA Wastewater Treatment Plant - EPA collected four surface soil samples, two subsurface soil samples, and one groundwater sample at the PRASA Wastewater Treatment Plant. Since VOCs were not detected in the samples, no PA/SI report was prepared for this facility.

• El Negro Auto Body/Parts Shop - EPA conducted an on-site reconnaissance of the facility; the facility appeared to be well maintained. One surface soil sample was collected from an open area adjacent to the facility. VOCs were not detected in the sample. EPA could not locate any detailed information regarding historical waste disposal practices at the facility. A PA/SI report was prepared for the facility recommending no further remedial action.

5

R2-0002565

• Total Gas Station- EPA collected two groundwater samples at the Total Gas Station. MTBE was detected at 14f.lg/L and 7f..Lg/L in the samples. Benzene was detected at 4f.lg/L and 20f..Lg/L, which exceeded the MCL threshold (5f..Lg/L). No PA/SI report was prepared for this facility due to the fact that benzene can be related to petroleum.

• Esso Gas Station - EPA collected three groundwater samples, including one duplicate, at the Esso Gas Station. Since no VOCs were detected in the samples, no PA/SI report was prepared for this facility.

• CAM- Background information provided by PRIDCO indicated that historical use of the CAM facility revolved around prefabricated piping in frame wall, plantain products and storage of lubrication oils. During this investigation, CAM used the site for intermittent storage of agriculture equipment. EPA collected four surface soil samples, two subsurface soil samples, and one groundwater sample from open areas adjacent to the CAM facility building using the Geoprobe™ direct-push method. No VOCs were detected in the samples. A review of available background information of this facility at the time did not indicate that these substances were generated by activities at the CAM facility, nor were any waste sources suspected of releasing or having the potential to release contaminants to groundwater or surface water identified at the CAM facility. A PA/SI report was prepared for the facility recommending no further remedial action.

• Juan Orozco Limited, Inc. - Juan Orozco manufactured guitars, guitar cases, and guitar strings. EPA collected four surface soil samples, two subsurface soil samples, and one groundwater sample from open areas adjacent to the facility building using the Geoprobe™ direct-push method. Analytical results indicated non-detect values for contaminants previously detected in the Maunabo public water supply wells as well as the remaining VOC parameters. A review of available background information at the time did not indicate that these substances were generated by activities at Juan Orozco Limited, nor were any waste sources suspected of releasing or having the potential to release contaminants to groundwater or surface water identified at the facility. A PA/SI report was prepared for the facility recommending no further remedial action.

• PRE- PRB used this facility for distribution of fruit-based beverages. Background information from PRIDCO indicated that historical use of the PRB site included bedroom furniture and plastic filter manufacturing, an emergency shelter, and parking for the Municipality of Maunabo. Hazardous substances utilized by former occupants at this site included sodium hydroxide, nitric acid, potassium hydroxide, and ehtylen glycol. Drums containing those substances were removed from the site by a PRIDCO contractor. EPA collected four surface soil samples, two subsurface soil samples, and one groundwater sample from open areas adjacent to the PRB facility building using the Geoprobe™ direct-push method. No VOCs were detected in the samples. A review of available background information at the time did not indicate that VOCs were generated by activities at PRB, nor were any waste sources suspected of releasing or having the potential to release to groundwater or surface water identified at the PRB facility. A PA/SI report was prepared for the facility recommending no further response action.

6

R2-0002566

• FEMA Storage Facility - FEMA uses this facility to store emergency supplies intended primarily for hurricane response. The facility was formerly operated by Caribe General Electric from an unknown date until 1995. Operations at the site consisted of the manufacture of high voltage contactors and resistors. The facility was vacant from 1995 until FEMA began operations in 2001. EPA collected five surface soil samples, including a duplicate sample, and two subsurface soil samples from open areas adjacent to the FEMA Storage Facility using the Geoprobe™ direct-push method. No VOCs were detected in the samples. A PA/SI report was prepared for the facility recommending no further remedial action.

• PHP- The PHP facility manufactured domestic plastic products by injection of plastic into moldings. Background information from PRIDCO indicated that historical use of the PHP site included furniture manufacturing and storage of emergency supplies for hurricane response. EPA collected four surface soil samples and two subsurface soil samples from open areas adjacent to the PHP facility using the Geoprobe™ direct-push method. No VOCs were detected in the samples. A review of available background information at the time did not indicate that VOCs were generated by activities at PHP, nor were any waste sources suspected of releasing or having the potential to release contaminants to groundwater or surface water identified at the PHP facility. A PA/SI report was prepared for the facility recommending no further remedial action.

EPA collected four background surface soil, two background subsurface soil, and one background groundwater sample. No VOCs were detected in the background samples. Based on the October and December 2005 data, EPA concluded that there was insufficient information to determine what the source of contamination of the public supply wells was.

EPA completed a Hazard Ranking System ("HRS") Documentation Package in 2006. The Site was listed on the National Priorities List on September 27, 2006.

EPA conducted a Remedial Investigation ("RI") at the Site from August 2010 to July 2011. From August 25 through September 29, 2010, a groundwater screening investigation was conducted at five potential source areas based on information provided in the SI and HRS Report and a field reconnaissance conducted by EPA contractor (CDM Smith). The groundwater screening investigation was conducted to provide screening-level data on the distribution of VOCs in groundwater. The screening data were used to support selection of the locations and depths of permanent monitoring wells and to identify potential source areas for subsequent soil sampling. Groundwater screening investigation samples were collected along four transects (Figure 3).

Groundwater screening samples were collected along the four transects oriented approximately perpendicular to the estimated groundwater flow direction. Groundwater screening samples were collected using a groundwater sampling system with a 4-foot screen attached to a direct push technology. At each location, samples were collected at 10 foot intervals, starting from the bottom of borehole and extending to the groundwater table. All screening samples were analyzed for trace-level VOCs with a 24-hour turn-around time.

7

R2-0002567

A summary of the groundwater screening collected from the five potential source areas is provided below:

• Transect 1 - East -Southeastern Potential Source Area - A total of 3 7 groundwater screening samples, including duplicates, were collected from four locations downgradient from a residential/commercial area and upgradient of Maunabo #4.

• Transect 1 - West - PRIDCO Potential Source Area - A total of 71 groundwater screening samples, including duplicates, were collected from 10 locations downgradient from CAM, Juan Orozco Limited, Inc., PRB and PRASA's Waste Water Treatment Plant.

• Transect 2 - Central Potential Source Area - A total of 10 groundwater screening samples, including duplicates, were collected from four locations downgradient ofthe Esso Gas Station and Maunabo Dry Cleaners.

• Transect 3 -Northern Potential Source Area - A total of 12 groundwater screening samples, including duplicates, were collected from four locations downgradient from the FEMA Storage Facility, PHP, and the Total Gas Station.

• Transect 4 - FMS Potential Source Area - A total of 31 groundwater screening samples, including duplicates, were collected from four locations downgradient from the FSM facility, south ofthe Maunabo River.

From December 10 through 22, 2010, a total of 64 additional groundwater screening samples, including duplicates, were collected and analyzed for VOCs. This groundwater screening sample supplemental sampling was conducted at nine additional locations. These additional locations were added to provide the data to refine and focus the locations and depths for permanent monitoring wells, including background monitoring wells.

Three groundwater monitoring wells were used to evaluate water quality upgradient of the impacted areas. Sediment and surface water background samples were collected upriver from the expected zone of impact in the Maunabo River.

A total of 16 monitoring wells were installed as part of the Rl. Two rounds of groundwater samples were collected from the 16 monitoring wells and the four public supply wells (Maunabo No. 1 through Maunabo No. 4). Round 1 was conducted between March 2 and 8, 2011 and round 2 was conducted between June 7 and 10, 2011.

As part of the RI, groundwater samples were collected from areas not expected to be impacted by site-related contamination to establish background. These samples were analyzed for the same analytical parameters as previous sampling events.

In order to identify potential sources of contamination, surface and subsurface soil samples were collected at the two areas which were suspected to be potential contaminant sources, the properties where the PRB facility and FSM area are located. These areas were identified as potential source areas based on the groundwater screening results. A summary of the findings per area is described below:

8

R2-0002568

• PRB facility - Surface and subsurface soil samples collected from the PRB facility did not identify a source of site-related VOCs. None of the six site-related VOCs was detected in soil samples from the PRB facility. However, one semi volatile organic compound ("SVOC"), bis(2-ethylhexyl)phthalate, and several metals exceeded screening criteria. The SVOC and metals are not considered to be Site-related and are not affecting the public supply wells.

• FSM area - Surface and subsurface soil samples collected from the FSM area did not identify a source of site-related VOCs. None of the six site-related VOCs were detected in soil samples from the FSM area. However, in surface soil samples, three SVOCs and 12 metals exceeded screening criteria, and one SVOC, benzo (a) pyrene, and eight metals exceeded their screening criteria in subsurface samples. The SVOC and metals are not considered to be site related and are not affecting the public supply wells.

Surface water, sediment, and porewater have not been impacted by discharge of site-related contaminants in groundwater. None of the six site-related VOCs was detected in the surface water, sediment, or porewater samples collected from the Maunabo River. No VOCs, SVOCS, pesticides, PCBs, or metals exceeded screening criteria in surface water or porewater samples. Six metals exceeded screening criteria in sediment samples, but they are not considered to be Site related.

COMMUNITY PARTICIPATION

The RI Report, the Human Health Risk Assessment ("HHRA") Report, the Screening Level Ecological Risk Assessment ("SLERA") Report, and the Proposed Plan (Appendix IV) for the Site were made available to the public in August 9, 2012. These documents along with the Administrative Record were made available to the public in the EPA Docket Room in Region 2, New York, Maunabo City Hall, EQB's Superfund File Room, and EPA Caribbean Environmental Protection Division's Office. Refer to Appendix I for copy of the Administrative Record Index for the Site. A public notice (Appendix V) announcing the availability of these documents and the date of the public meeting was published in the El Nuevo Dfa newspaper on August 9, 2012 and La Esquina, a local newspaper, 1st Edition August 2012, edition# 452 dated August 9, 2012. A public comment period was held from August 9, 2012 to September 7, 2012.

In addition, a public meeting was held on August 29, 2012 at the Maunabo City Hall, Maunabo, Puerto Rico to present the Proposed Plan to a broader community audience than those that had already been involved at the Site. Refer to Appendix VI for copy of the attendance signing sheet. At this meeting, representatives from EPA and EQB answered questions about the activities conducted at the Site and the remedial alternatives. EPA also used this meeting to solicit a wider cross-section of the community input on the proposed remedial alternative for the Site.

No substantive comments were received during the meeting. Refer to Appendix VII for official transcript of the public meeting. EPA prepared a Responsiveness Summary addressing all comments received during the public comment period. The Responsiveness Summary is included in Part III of this Record ofDecision.

9

R2-0002569

SCOPE AND ROLE OF ACTION

The principal problem at the Maunabo Groundwater Contamination Site is the presence of groundwater contamination at levels that represent an unacceptable risk to human health and the environment. The Site consists of three contamination plumes: a cis-1 ,2-DEC plume, a PCE plume, and a 1,1-DCE plume. The groundwater contamination has been defined in sufficient detail to complete the RI Report and prepare a Feasibility Study ("FS") and a Baseline Risk Assessment (which includes the HHRA and SLERA).

SITE CHARACTERISTICS

Conceptual Site Models Contamination at the Site may be linked to previous releases and discharges to the environment. Results of the RI indicate there was insufficient information to conclusively determine the source(s) of contamination of the drinking water supply wells. People living, working, or recreating at the Site may be exposed to contaminants in soil, groundwater, surface water, and sediment. Conceptual Site Models ("CSMs"), illustrating how chemicals may move from historical release points to locations where human exposure may occur, are developed to provide a roadmap to these possible exposures. The current and future land-use CSMs for the Site are illustrated below.

10

R2-0002570

lagand:

l"rrnBll ---

'~H'II'4 ,~ .. N"..et~

:: .. "111U~~~

·llOI'I'fJie'le~~ a~~~

Conceptual Site Model for Maunabo Groundwater Contamination Site

Current Land-Use Scenario

- Cool-ftaidwnl ""' ... - ........... r..._ .. -- \II-

Adlittli.lm!.t

""""" - __.,. c..-. ~1·12~2,J

0 0

I •

I •

I 0 0 • • () 0 • • 0 ("' v 0 0 0 0 0 0 0 0 0 0

I •

I •

I r) " 0

• • 0 (''

'"'' • • 0 0

0 0 II 0 0 I I 0 0 0 0

0 0 II

0 0 I I 0 0 0 0

• • • 0 0 0

0 0 0

0 0

0 0

_,__

~ Adub.md (1·11 'fV*tljj ;>,;:fdd.~tv,

• • • • • • 0 0 0 0 0 0

l..,_,./ 0 0 0 0 0

0 0 0 0

0 0 0 0

--

EE lEE

R2-0002571

lBgllnlt

l"rtnWy ~

- IOOOI!doly --- --

\~1-0f'~ !}.,N:J'~,.t ,.~.~-fd::xtc

L'all'M"~&

·~~~ a~~~

"-"• -

Conceptual Site Model for Maunabo Groundwater Contamination Site

Future Land-Use Scenario

--

0 0 0 0 0 0

• • • • 1·1 • II • •••· 1·: I ••• : : : 1---=:::::----1--~-+: ---':--i:l----:~

C· 0 0 0 0 • C' u 0 0 • 0 0 0 0 0 • 0 0 0 • 0 0 0 0 0 • 0 0 0 • 0 0 0 0 0 0 0 0 0 0 0 0 0

,~,

\j 0 0 0 0 0 0 0 r~,

v 0 0

0 0 II () 0 0 0 II 0 0 0 0 II 0 0 0 0 0 0 0 0 0 0

0 0 II 0 0 0 0 II 0 0 0 0 II 0 0 0 0 0 0 0 0 0 0

Tile 6llle!- Maunallo ~'iller Ctn!an'lllil1oo Sll!!. WI!H:Illnai.XIe fOO!Iff &gar ldQ il1ll PUe!1D Rim B~ Area6

--0 0 0 0 0 0

:1"\ ,,, '...! '-'

0 0 0 0

(J • 0 • 0 • • 0

• 0

• 0

• 0

R2-0002572

Site Overview The Site is located in the municipality of Maunabo, in the southeastern coastal area of Puerto Rico (18° 00' 20.6" north latitude and 65° 54' 19.5" west longitude), within an isolated alluvial river valley (Figure 1 ). The Site is surrounded by mountains to the north, east, and west and the Caribbean Sea to the southeast. The highest point in the area is Cerro La Pan dura at 1, 700 feet above mean sea level (msl) and the lowest point is the Caribbean Sea to the southeast. The Maunabo River and several intermittent streams are located in the Site vicinity and flow to the southeast toward the Caribbean Sea.

Regional Geology The Site is located within an alluvial valley surrounded by hills composed of igneous plutonic rocks. The two strata encountered at the region are the Quaternary-age alluvium deposits and the underlying Late Cretaceous-age igneous plutonic rocks mapped as the San Lorenzo Batholith on the Punta Tuna!Y abucoa Quadrangle geologic map. Tonalite outcrops of the Punta Guayanes Complex are located southwest and southeast of the Site. Other units near the site are metavolcanic rocks to the southwest and small outcrops of metamorphic amphibole hornfels west and southeast of the site. The units expected to be beneath and adjacent to the Site are Unconsolidated Deposits - Quaternary Alluvium Deposits and Bedrock. A brief description of these units is described below.

Unconsolidated Deposits - Quaternary Alluvium Deposits The Quaternary alluvium deposits consist of unconsolidated silt, clay, sand, and gravel and underlie the Maunabo River valley. The lithology varies widely with numerous discontinuous lenses of clay, silt, and sand. The thickest and most permeable deposits are located within the center of the alluvial valleys and can be up to 200 feet thick.

Bedrock The San Lorenzo Batholith is a large expanse of granitic rock that covers an area of 200 square miles, and is one of the most geologically prominent features in southeastern Puerto Rico. It formed during the Late Cretaceous Age when cooling magma formed plutons that eventually converged to form the batholiths, very large intrusive igneous rock mass. The batholith includes three major units, which in chronological order (oldest to youngest) include diorite and gabbro, the San Lorenzo granodiorite and tonalite, and the Punta Guayanes plutonic complex. The Punta Guayanes complex ranges from tonalite to quartz monzanite and is generally concentrated in the outer portion of the batholith. A prominent structural feature is an unnamed fault bisecting the Maunabo River valley. The fault strikes northwest to southeast with jointing perpendicular to the fault. In the northwest, the fault runs parallel to the Maunabo River. The noticeable lithologic break between the rocks to the north and south may represent a fault zone that existed during development of the San Lorenzo batholith in Late Cretaceous time but eventually healed. The units expected to be beneath and adjacent to the site are described below.

13

R2-0002573

Regional Hydrogeology Groundwater is most abundant in the unconfined alluvial aquifer of the Maunabo River Valley. The underlying igneous plutonic bedrock yields generally small to moderate quantities of water. Data from test holes, observation wells, irrigation wells, and public supply wells in the Maunabo River Valley were used to estimate the hydrogeologic characteristics of the alluvium and bedrock aquifers. The hydraulic conductivity of the bedrock and alluvium were reported to be less than 1 foot per day (ft/day) and 10 to 100 ft/day, respectively. The estimated average transmissivity for the alluvial aquifer is 4,000 square feet per day, and the specific capacity is 20 gallons per minute per foot of drawdown. Groundwater flow direction within the alluvium is at an oblique angle toward the river, in the direction of river flow.

The highest point in the area is Cerro La Pan dura at 1, 700 feet msl and the lowest point is the Caribbean Sea to the southeast. The Maunabo River and several intermittent streams are located in the Site vicinity and flow southeast toward the Caribbean Sea. The topography in the area slopes south to southwest from the nearby hills, approximately 180 feet msl, toward the Maunabo River at 30 feet msl.

The drainage basin area of the Maunabo River is approximately 18 square miles, with the headwaters in Cerro La Torresilla. The upper reach of the river flows through steep, igneous rock terrain where the average gradient is 230 ftlmi. The river meanders through the alluvial valley, where the average gradient is much lower (13 ft/mi), before discharging into the Caribbean Sea. The estimated average discharge of the Maunabo River near the Site is 25 ft3 /s. Flow is variable throughout the year, with the lowest flow occurring during the dry winter and spring months. Groundwater discharge forms the base flow for the river, which receives nearly 50 percent of its annual flow from the alluvial aquifer. However, RI data collected shows that, at certain times of the year such as the dry season, it can be a losing river. Groundwater also discharges to some of the smaller tributaries and streams (or "quebradas") such as Quebradas Arenas, Talante, de los Chinos, and Tumbada. These quebradas generally stop flowing during the dry season. The cessation of flow in the quebradas during dry periods is consistent with the seasonal fluctuation in the water table observed during the remedial investigation.

Site-Specific Geology Observations of the lithologies from soil cuttings and soil samples collected during groundwater screening and monitoring well installation indicate that interbedded silty sand and clay were the dominant sediment types. This variability confirms the heterogeneous nature of the alluvial overburden sediments. Well logs obtained from PRASA and the United States Geological Survey for the public supply wells generally described the sediments as clayey sand with some layers of coarse sand and gravel. At Maunabo #2, the lithology is described as clayey sand to 15 feet, coarse brown sand with silt to 120 feet, weathered bedrock to 125 feet, and bedrock at 125 feet. At Maunabo #3, the lithology is described as sandy yellow clay and gravel to 30 feet, gravel, sand and clay to 42 feet, fine gravel, sand and clay to 80 feet, and yellow clay with gravel to 100 feet. At Maunabo #4, the lithology is described as clayey sand to 80 feet, brown clay/rock to 90 feet. Lithology information was not available for Maunabo #1.

14

R2-0002574

Site-Specific Hydrogeology The elevation of the Site area is approximately 40 feet msl. The Site lies between the Quebrada Arenas to the east and the Maunabo River to the southwest. Most of the drainage across the Site vicinity flows southwest, toward the Maunabo River. The aquifer of concern in the Maunabo area is the alluvial aquifer of the Maunabo River Valley.

Slug tests were conducted in February 2011 at 11 monitoring wells to obtain sitespecific hydraulic conductivity information. The slug test results show that the mean hydraulic conductivity values ranged from 0.43 foot/day to 35.41 feet/day.

Conductivities ranging from 10 to 1,000 feet/day generally occur in well sorted sand or gravel soils. It is possible that the presence of gravel at this location may allow for more groundwater movement resulting in the higher hydraulic conductivity value.

Groundwater flow velocities were estimated at the Site using the estimated hydraulic conductivity values derived from slug tests, gradients measured using Round 1 and Round 2 water level elevation data, and literature values of effective porosity based on lithology. Flow velocities were estimated in four areas of the Site. The estimated flow rates ranged from 0.06 to 0.61 foot/day. Groundwater flow in the alluvial aquifer generally is toward the Maunabo River, on both sides of the river, although flow is affected by pumping of the supply wells, especially Maunabo #1 and Maunabo #4.

Groundwater elevation data from the southwest side of Maunabo River, near the FSM area, shows decreasing water level elevations toward the river (12.11 feet msl to 9.61 feet msl). The groundwater elevation contours from Round 2, collected during the wet season, indicate higher overall potentiometric surface, although groundwater flow remains toward Maunabo River from both sides of the river. Round 2 was collected in June, following major rainfall events in May. In the vicinity of Maunabo #4, groundwater flow is southeast toward Maunabo #4 with a southern component toward Maunabo River.

Groundwater/surface water interaction was evaluated to assess the potential for contaminated groundwater to discharge to the Maunabo River. In March 2011, in conjunction with the synoptic water level data collected from monitoring wells, water level data were collected from three piezometers and a stream gauge installed in the bed ofthe Maunabo River. During Round 1 (March 2011 dry period), average water elevation was 10.57 feet above msl, which is greater than groundwater elevations near the stream. The stream water elevation on the Maunabo River staff gauge (1 0.58 feet above msl) was also greater than the groundwater elevation near the stream. The stream and groundwater elevation data collected during the March 2011 dry period indicate that the groundwater table is below the stream bed, suggesting that the Maunabo River is a losing stream. This is likely as a result of a combination of seasonal lowering of the groundwater table and effects of pumping at Maunabo #1. Round 2 groundwater elevations collected during a wet period (June 2011) are generally higher and intercept the bed of the Maunabo River, suggesting that the stream is gaining. Based on the remedial investigation data, the Maunabo River

15

R2-0002575

reflects changes from a gaining stream during wet periods to a losing stream during dry periods. Pumping effects from Maunabo # 1 are overlaid on the seasonal pattern, lowering groundwater levels locally during both dry and wet periods. Groundwater in the southeastern portion of the Site near Maunabo #4 is also believed to move toward the Maunabo River, which turns in a southerly direction in that area. It is also believed that the bend in the Maunabo River toward the south means that the groundwater flow moves toward the south in this area. As with Maunabo #1, when Maunabo #4 is actively pumping it is likely drawing the groundwater toward it.

Cultural Resources A cultural resources survey was conducted in the Site area by Richard Grubb & Associates, Inc. ("RGA"). In October 2011, the Stage 1 A level Cultural Resources Survey was completed on and around the Site. The Stage lA survey is the initial level of a cultural resource investigation and requires a comprehensive documentary research designed to identify known or potential historical, architectural, and/or archaeological resources within the area of potential effects ("APE"), a 375 acre area in the municipality of Maunabo. The Stage lA cultural resources survey was conducted in compliance with Section 106 of the National Historic Preservation Act of 1966, as amended, and the Standards and Guidelines for Archeology and Historic Preservation (FR Vol. 48, No. 190), 36 C.P.R. Part 800: Protection of Historic Properties, and the Council for Protection of Land Based Archeological Resource' "Reglamento Para Investigaciones de Recursos Arqueologicos Terrestres ". The work was performed under the direction of a registered professional archeologist, who met the requirements of 36 C.P.R. 61. The Stage 1A report was prepared in conformance with the standard report format included in these guidelines and reflects contemporary organization and illustrative standards currently used in the field of professional cultural resource management. RGA evaluated the potential for any historical, architectural, or archaeological resources that might be impacted by the project activities and determined the probability that archaeological resources were present within the project area. The ruins of an historic sugar mill and a prehistoric and Colonial-Period site were indentified within and near the APE boundary. The southeastern portion of APE possesses a high sensitivity for archeological resources associated with another historic site (Hacienda Bordelese). Much of the remaining Site area, including the densely developed downtown area, has low potential for archeological resources. RGA recommended that a Stage lB archeological survey should be conducted if subsurface disturbance for remediation is planned in areas identified as having high to moderate archeological sensitivity.

Sampling Strategy The characterization of Site conditions emphasizes the spatial distribution of Site-related contaminants in Site media. The first step in this characterization was the selection of screening criteria to evaluate contaminants detected in Site media. Whenever possible, established regulatory criteria, known as chemical-specific applicable or relevant and appropriate requirements ("ARARs"), were used for the screening criteria values. In the absence of ARARs, guidance values, known as "to be considered" ("TBC"), were used.

For groundwater contaminants, the MCL was used, followed by the Regional Screening Level for tap water if no MCL exists.

16

R2-0002576

Criteria for surface water contaminants are drawn from the Puerto Rico Water Quality Standards for Class SD surface water, when available. Otherwise, values were chosen from the National Recommended Water Quality Criteria for Priority Pollutants.

For soil contaminants, the Site screening criteria are the lowest of the human health criteria, ecological criteria, or protective of groundwater criteria drawn from the Regional Screening Levels for Contaminants at Superfund sites for residential soil or for protection of groundwater or various ecological screening levels guidelines.

For sediment contaminants, the Site screening criteria are the lower of either the human health criteria or the criteria stated in the Regional Screening Levels for Contaminants at Superfund sites for residential soil or for protection of groundwater or various ecological screening levels guidelines ..

Sources of Contamination In December 2005, EPA conducted a limited investigation to identify possible sources of groundwater contamination in Maunabo. Facilities that were investigated include the former Maunabo Municipal Solid Waste Landfill (Maunabo Landfill), PRASA's Wastewater Treatment Plant located close to Maunabo #1, El Negro Auto Body/Parts shop, Total Gas Station, Esso Gas Station, and five light industrial facilities operating under the auspices of PRIDCO. The five identified PRIDCO industrial facilities are: CAM; Juan Orozco Limited, Inc; PRB; FEMA Storage Facility; and PHP. The investigation concluded that no further action is required for these areas.

The RI for the Site that was conducted from August 2010 to July 2011, however, identified three contaminated groundwater plumes: a cis-1 ,2-DCE plume, a PCE plume, and a 1, 1-DCE plume. The configuration of the cis-1,2-DCE plume indicates that a release of Site-related contaminants, most likely PCE or TCE, occurred at or near the property where the PRB facility is located. Cis-1 ,2-DCE, a degradation product of TCE, was the contaminant found at the highest concentration (up to 300 Jlg/L ). Related VOCs including trans-! ,2-DCE, 1, 1-DCE, and vinyl chloride are also present, but at much lower concentrations. The source of the other two plumes is currently unknown.

Types of Contaminants and Migration In general, VOCs were the most commonly detected contaminants which included the Siterelated compounds PCE, TCE, cis-1,2-DCE; trans-1,2-DCE, 1,1-DCE, and vinyl chloride. VOCs are very soluble in groundwater and have relatively moderate to high vapor pressure. In addition, VOCs tend to have a long residence time in groundwater. The fate of a chemical in the environment is a function of its physical and chemical properties and conditions at the Site. The potential for environmental transport is a function of the conditions at the Site, including geological and hydrogeological characteristics. The primary fate and transport aspects ofthe Site are summarized below.

• The greatest potential for the transport of the Site-related VOCs is through groundwater migration. Site related VOCs are volatile and generally do not adhere to soil or sediment. As such, they have migrated from source areas to the water table and down into the groundwater.

• Several types of data at the cis-1,2-DCE plume provide significant evidence that PCE concentrations are decreasing naturally via reductive dechlorination. Evidence

17

R2-0002577

includes the presence of biodegradation daughter products such as cis-1,2-DCE and vinyl chloride, high chloride concentrations, methanogenic conditions, as well as statistically significant evidence of decreasing trends for PCE, TCE, cis-1 ,2-DCE, and 1, 1-DCE concentrations at Maunabo # 1.

• The 1,1-DCE Plume is currently in an anoxic denitrifying condition that may not support anaerobic degradation of 1,1-DCE to vinyl chloride and ethane.

• Anaerobic reductive dechlorination of PCE in the PCE plume is very limited. • Although extensive dechlorination took place at the cis-1,2-DCE plume, complete

dechlorination has yet to occur, as indicated by the cis-1,2-DCE, 1,1-DCE, and vinyl chloride remaining at the Site. This may be attributable to the lower degradation rates of cis-1,2-DCE and vinyl chloride, and the lack of sufficient organic carbon to support complete and sustainable reductive dechlorination of chlorinated VOCs year round.

As mentioned above, based on the groundwater data collected during the RI, there are three separate plumes (cis-1,2-DCE, PCE, and 1,1-DCE) at the Site. The plumes are located in different areas of the Site and have characteristic contaminant profiles. A brief description for each of the three plumes is as follows:

• cis-1,2-DCE Plume - The configuration of this plume indicates that a release of Site-related contaminants, most likely PCE or TCE, occurred in or near the building housing the PRB facility. Cis-1 ,2-DCE, a degradation product of TCE, was found at the highest concentrations (up to 300 f..lg/L). Related VOCs including trans-1,2-DCE, 1,1-DCE, and vinyl chloride are also present, but at much lower concentrations. Only cis-1,2-DCE (up to 300 f..lg/L) and vinyl chloride (up to 1.8 f..Lg/L) exceed the groundwater screening criteria. Site-related groundwater contamination was not detected in groundwater up gradient of the PRB Area. The plume is migrating toward the southwest, influenced by pumping at the Maunabo #1 and groundwater flow toward the Maunabo River. The plume generally is bounded upgradient, to the southeast, and northwest.

• PCE Plume - The primary contaminant in this plume is PCE, which is present at concentrations exceeding screening criteria in one monitoring well (8.5 J f..lg/L) and one screening location (7.4 ~Lg/L). TCE was also detected, but concentrations were well below the screening criteria of 5 f..lg/L. The plume is migrating toward the northeast, influenced by pumping at the Maunabo # 1 and groundwater flow toward the Maunabo River. The downgradient edge of the plume is the Maunabo #1.

• 1,1-DCE Plume- This plume is located northwest of Maunabo #4 and differs from the FSM Area and PRB Area plumes in that it consists almost entirely of 1, 1-DCE. The highest concentration of 1, 1-DCE detected was 25 f..lg/L. Also, 1, 1-DCE was detected in the Maunabo #4 (1.1 f..lg/L). The plume appears to be migrating toward the southeast, toward Maunabo #4. However, the plume may also be migrating toward the southwest, influenced by groundwater flow toward the Maunabo River. The source of this plume is unknown.

18

R2-0002578

Current and Potential Future Land and Water Uses

Land Uses The land above the three plumes is currently a mix with uses for residential, recreational, commercial, and industrial purposes. The future use the land is expected to remain the same as the current uses.

Groundwater and Surface Uses The groundwater is considered as a drinking water supply for current and future uses. The surface water (Maunabo River) is currently used for recreational purposed, and it is expected to be used for the same purpose in the future.

SUMMARY OF SITE RISKS

As part of the RI and FS, EPA conducted a baseline risk assessment to estimate the current and future effects of contaminants on human health and the environment. A baseline risk assessment is an analysis of the potential adverse human health and ecological effects of releases of hazardous substances from a site in the absence of any actions or controls to mitigate such releases, under current and future land uses. The baseline risk assessment includes human health risk assessment and an ecological risk assessment. It identifies the contaminants and exposure pathways at the Site (referred to the CSMs) and provides the basis for the need for a remedy, if conditions exist to support the need.

Summary of HHRA The chemicals of potential concerns ("COPCs") identified for the Site are based on criteria outlined in the Risk Assessment Guidance for Superfund, primarily through comparison to risk-based screening levels. Two SVOCs (benzo(a)pyrene and dibenzo(a,h)anthracene) and eight inorganics (aluminum, arsenic, chromium, cobalt, iron, manganese, thallium, and vanadium) are identified as COPCs in the surface and subsurface soil at the FSM area. Seven inorganic compounds (aluminum, arsenic, chromium, cobalt, iron, manganese, and vanadium) are identified as COPCs in the surface and subsurface soil at the PRB area. Five VOCs (cis- I ,2-dichloroethene, tetrachloroethane, trans- I ,2-dichloroethene trichloroethene, and vinyl chloride) and nine inorganic compounds (aluminum, arsenic, barium, chromium, cobalt, copper, iron, manganese, and vanadium) are identified as COPCs in the groundwater. Two VOCs (bromodichloromethane and dibromochloromethane) and six inorganic compounds (arsenic, chromium, cobalt, iron, manganese, and vanadium) are identified as COPCs in sediment from the Maunabo River.

Exposure pathways evaluated for soil include ingestion of and dermal contact with soil, inhalation of particulates from soil by commercial/industrial workers, trespassers, residents, and construction workers. Exposure pathways evaluated for groundwater include ingestion of and dermal contact with groundwater, inhalation of vapor released during showering and bathing, and inhalation of vapor through vapor intrusion by commercial/industrial workers and residents. Exposure pathways evaluated for surface water and sediment include ingestion of and dermal contact by recreational users.

Risks for all receptors are estimated using reasonable maximum exposure ("RME") assumptions. Risks are also estimated using central tendency exposure ("CTE") assumptions when the RME assumptions resulted in risk estimates above EPA's thresholds. The

19

R2-0002579

comparison of RME and CTE risks provides information about the degree to which variability in and uncertainty associated with receptor behavior (e.g., amount of water a child ingests per day) influence the risk estimates. CTE risks represent typical exposure patterns rather than the highest possible exposure that is reasonably expected to occur.

The current uses identified for the Site are: commercial/industrial workers at the FSM and PRB; trespassers at the FSM and PRB; residents at the FSM; and recreational users at Maunabo River. The future uses for the Site are: commercial/industrial workers at the FSM and PRB; trespassers at the FSM and PRB; residents at the FSM, PRB, and the Maunabo River; recreational users at Maunabo River; and construction workers at the FSM and PRB. In addition, the potential future use of groundwater will be as a drinking water source for the community once safe cleanup levels have been achieved. Hence, the human health risk assessment focused on health effect for both children and adults, in a residential setting, that could result from current and future direct contact with (1) contaminated soil (e.g., children ingesting soil), and (2) contaminated groundwater (e.g., through ingestion and inhalation of volatile compounds.

Non-Carcinogenic Health Hazards The health hazards of non-carcinogens are assessed by comparing the chronic daily intake ("CDI") of a contaminant to its reference dose ("RID"), the RID being a benchmark for safety by virtue of its being based on the contaminant's threshold for causing adverse health effects, to which multiple safety factors are added. The ratio of the CDI to the RID is referred to as the Hazard Quotient ("HQ"). A HQ greater than 1 may be associated with adverse health effects. To assess the overall potential for non-carcinogenic effects posed by simultaneous exposure to multiple contaminants, EPA has developed the Hazard Index ("HI"), which is the sum of all HQs within a particular exposure pathway. In the event that the addition of multiple sub-threshold HQs (i.e., HQ less than 1) exceeds an HI of 1, adverse health effects may result if the individual contaminants are believed to share a similar mechanism of action or toxic endpoint. This approach assumes that sub-threshold chronic exposures to multiple chemicals are additive

A HQ value greater than 1 indicates that a calculated exposure is greater than the RID for a given constituent and that there may be some potential for health concerns. Similarly, a HI greater than 1 indicates that overall exposure to all COPCs may present a concern.

For the current and future land-use scenarios, total non-cancer health hazards are within EPA's target threshold (HI of 1) for all receptors under the RME scenario, except commercial and industrial workers, construction workers, and residents at both the FSM and PRB areas. The current and future commercial/industrial workers, construction workers, and residents have non-cancer HI exceeding EPA's threshold of unity under the RME scenario for the kidney, respiratory system, lung, and gastrointestinal ("GI") tract. Non-cancer health hazards for current and future commercial/industrial workers and construction workers are almost entirely due to the hypothetical use of contaminated groundwater as a potable water supply. For current and future residents, the potential health hazards to the kidney are results of exposure of cis-1,2-DCE and vanadium in groundwater, while the potential adverse health effects to the respiratory system are results of exposure to vanadium in soil and groundwater. The potential adverse health effects to the lung and GI tract are mainly results of exposure to arsenic and iron, respectively, in both soil and groundwater. Under the CTE scenario, the His

20

R2-0002580

still exceed EPA's threshold of unity for the same target organs/effects, except lung and GI tract, affected under the RME.

Non-Cancer Health Hazard Scenarios (Current Scenario)

Scenario Area Hazard Index (HI)

Commercial and Industrial FSM Total HI= 5 (RME) Workers Kidney: HI= 5

Respiratory System: HI=4

Total HI= 4 (CTE) Kidney: HI= 3 Respiratory System: HI= 3

PRB Total HI= 5 (RME) Kidney: HI= 4 Respiratory System: HI= 4

Total HI= 3 (CTE) Kidney: HI= 3 Respiratory System: HI= 3

Trespasser FSM Total HI = 0.8

PRB Total HI = 0. 7

Residents FSM Total HI = 36 (RME) Kidney HI= 32 Respiratory System HI= 30 Lung HI= 2 GI Tract HI= 2

Total HI= 16 (CTE) Kidney HI= 14 Respiratory System HI= 13

Recreational Users Maunabo River Total HI= 1

Non-Cancer Health Hazard Scenarios (Future Scenario)

Scenario Area Hazard Index _mn_

Construction Workers FSM Total HI =2 Kidney: HI = 2

21

R2-0002581

Respiratory System: HI= 2

PRB Total HI= 2 Kidney: HI = 2 Respiratory System: HI = 2

Residents PRB Total HI = 34 (RME) Kidney HI = 31 Respiratory System HI= 4 Lung HI= 2 GI Tract HI = 2

Total HI= 15 (CTE) Kidney HI = 13 Respiratory System HI = 13

Maunabo River Total HI= 0.007

Carcinogenic Risk Carcinogenic risk is expressed as a probability of developing cancer over the course of a lifetime as a result of a given exposure level. To assess overall cancer risk, risks from various COPCs are assumed to be additive and are summed. EPA uses a range of cancer risks of 1 x 1 o-4 to 1 x 1 o-6 as an acceptable risk range and the Agency strives to ensure that risks are within or below this range as part of a Superfund cleanup.

To assess overall cancer risk, risks from various COPCs are assumed to be additive and are summed. EPA uses a range of cancer risks of 1 x 1 o-4 to 1 x 1 o-6 as a "target range within which the Agency strives to manage risks as part of a Superfund cleanup". The NCP states that "for known or suspected carcinogens, acceptable exposure levels are generally concentration levels that represent and excess upper bound lifetime cancer risk to an individual ofbetween 1 x 104 to 1 x 10-6

".

For the current land-use scenario, total estimated cancer risks are within EPA's target range (cancer risk of 1 x 10-4 to 1 x 1 0-6) for all receptors under the RME scenario, except commercial industrial workers at both the FSM and PRB areas and residents at the FSM. However, under the CTE scenario for residents at the FSM, the total cancer risk is within the cancer risk range of 1 x 1 0·4 to 1 x 10-6.

Scenario

Commercial Industrial Workers

Trespasser

Cancer Risk Scenarios (Current Scenario)

Area

FSM

PRB

FSM

22

Cancer Risk

4 X 10-'

4 X 10-5

9 X 10-1

R2-0002582

PRB I X 10-6

Residents FSM 2 x I o-4 (RME)

8 x I o-5 (CTE)

Recreational Users Maunabo River 9 X 10-'

For the future land-use scenario, total estimated cancer risks are within EPA's target range (cancer risk of 1 xI oA to I xI 0-6

) for all receptors under the RME scenario, except residents at the FSM and recreational users of the Maunabo River. In addition, under the CTE scenario for residents at the FSM, the total cancer risk is not within the cancer risk range of I xI 0-4 to I xi0-6.

Cancer Risk Scenarios (Future Scenario)

Scenario Area Cancer Risk

Future Construction Workers FSM 2 X 10-t

PRB 8 X 10-8

Trespasser FSM 9 X 10-1

PRB 1 X 10-6

Residents FSM 2 x I o-4 (RME)

8 X 10-5 (CTE)

Maunabo River 2 x Io-5

Recreational Users Maunabo River 9 X 10-/

Summary of SLERA A SLERA was conducted to evaluate the potential for ecological risks from the presence contaminants in surface soil, sediment, porewater and surface water. The SLERA focused on evaluating the potential for impacts to sensitive ecological receptors to Site-related constituents of concern through exposure to soil, sediment, porewater and surface water. Concentrations of compounds detected in surface soil, sediment, porewater and surface water were compared to ecological screening values as an indicator of the potential for adverse effects to ecological receptors. A complete summary of all exposure scenarios can be found in the SLERA Report, which is part of the Administrative Record for this Site.

Based on a comparison of maximum detected concentrations of contaminants in Site soil, sediment, porewater, and surface water, to conservatively derived Ecological Screening

23

R2-0002583

Levels (ESLs), the potential for ecological risk may occur. The COPCs identified by media at the Site are:

• Soil: cadmium, chromium, copper, lead, manganese, mercury, vanadium, and zinc • Sediment: copper • Porewater: aluminum, barium, and iron • Surface water: barium

The following media-specific contaminants (VOCs and metals) were all retained as COPCs due to a lack of media-specific ESLs.

• Soil: carbazole • Sediment: barium and vanadium • Surface water: bromodichloromethane and dibromochloromethane

Based on a comparison of maximum detected concentrations of contaminants in Site soil, sediment, surface water, and porewater to conservatively derived ESLs, the potential for ecological risk may occur. The COPCs identified by media at the Site are:

• Soil: cadmium, chromium, copper, lead, manganese, mercury, vanadium, and zinc • Sediment: copper • Surface water: barium • Porewater: aluminum, barium, and iron

The following media-specific contaminants (VOCs and metals) were all retained as COPCs due to a lack of media-specific ESLs:

• Soil: carbazole • Sediment: barium and vanadium • Surface water: bromodichloromethane and dibromochloromethane

COPC retained via comparison to their respective media-specific ESLs were all comprised of metals and several non-site related VOCs and a pesticide were retained due to a lack of a screening value. However, there were not Site-related chemicals detected in any media evaluated in this SLERA. The compounds detected above conservative ESLs or those that were retained due to a lack of a screening value are most likely reflective of natural conditions, or non Site-related sources. Therefore, the Site poses no Site-related risk to ecological communities present.

It is EPA's current judgment that remedial action is necessary to protect public health, welfare, and the environment from actual or threatened releases of hazardous substances into the environment.

REMEDIAL ACTION OBJECTIVES

Remedial action objectives (RAOs) are specific goals to protect human health and the environment. These objectives are based on available information and standards, such as ARARs, TBC guidance, and Site-specific risk-based levels.

The RAOs for the Site are:

24

R2-0002584

• Protect human health by preventing exposure via ingestion, inhalation, or dermal contact to contaminated groundwater with concentrations above Preliminary Remediation Goals ("PRGs"); and

• Remediate the groundwater to the extent practicable by reducing Site contaminant concentrations to PRGs

Contaminated groundwater is the media of interest for the Site. Surface and subsurface soil samples collected during the RI did not identify a source of Site-related VOCs. Site related contaminants are chlorinated volatile organic compounds, including PCE, TCE, cis-1,2-DCE, 1, 1-DCE. These contaminants may pose risks to human health through inhalation, ingestion, and dermal contact.

PRGs for the Site The National Primary Drinking Water Standards, MCLs (40 C.P.R. 141), are the relevant and appropriate chemical-specific ARAR for the contaminated groundwater at the Site. Groundwater at the Site is classified as SG, suitable for drinking water use, and it is currently utilized as a source of potable water supply. Therefore, federal drinking water standards are applicable requirements. PRGs which are the groundwater cleanup goals, have been derived from chemical-specific ARARs for this Site, and are presented in the table below.

Preliminary Remediation Goals for auna o roun wa er on amma IOn uper un 1 e M b G d t C t . f S ti d s·t

Chemicals of Potential Concern National Primary Drinking Preliminary Water Standards (EPA Remediation Goals Maximum Contaminant

Levels) Tetrachloroethene (PCE) 5 J.tg/L 5 J.tg/L cis-1 ,2-dichloroethene ( cis-1 ,2-DCE) 70 J.tg/L 70 J.tg/L 1,1-dichloroethene (1,1-DCE) 7J.tg/L 7J.tg/L

Even though the PRGs are the ultimate concentration goals for Site cleanup, site-specific situations and limitations on currently available technologies may prevent the remedial action to achieve the PRGs within a reasonable time frame.

DESCRIPTION OF THE ALTERNATIVES

Remedial Alternatives Remedial alternatives were assembled by combining the retained remedial technologies and process options for the contaminated media and evaluated in the FS, as required in the NCP. The remedial alternatives which were evaluated to address groundwater contamination in the three plumes are summarized below.

Alternative l:No Action The No Action alternative is retained for comparison purposes as required by the NCP. No remedial action would be implemented as part of this alternative. It does not include any institutional controls or monitoring program. According to CERCLA, alternatives resulting in contaminants remaining above levels that allow for unrestricted use and unlimited exposure require that the Site be reviewed at least once every five years.

25

R2-0002585

Alternative 2: Monitored Natural Attenuation ("MNA") MNA relies upon naturally occurring destructive mechanisms (biodegradation) to address the cis-1,2-DCE and 1,1-DCE plumes and nondestructive mechanisms (dilution and dispersion) to address the PCE plume. Routine monitoring and contaminant concentration trend analysis are generally performed as part of the MNA response action to demonstrate that contaminants do not represent significant risk and that degradation is occurring. If monitoring indicates that levels are not decreasing sufficiently, a contingency plan would need to be implemented. If asymptotic contaminant concentration levels are achieved, an active remedy (e.g., targeted injection, etc.) may be necessary to achieve PRGs.

To address the uncertainty surrounding contaminant concentration reduction via MNA, a pre-design MNA investigation would be required in order to provide information to better project the effectiveness of natural attenuation mechanisms at field scale and to confirm that active degradation of contaminants is occurring where needed.

Institutional controls such as deed restrictions and well drilling restrictions would be implemented to eliminate the exposure pathways of contaminated groundwater to receptors. Long-term monitoring would involve annual groundwater sampling and periodic reviews to monitor and evaluate contaminant migration and concentration changes in the aquifer.

Five year reviews will have to be performed for the same reasons stated in Alternative 1.

Alternative 3: Air Sparging/Soil Vapor Extrusion (for the cis-2,2-DCE plume) and Monitored Natural Attenuation (for the PCE and 1,1-DCE plumes) MNA would be implemented for the PCE and 1,1-DCE plumes as presented in Alternative 2. In addition, air sparging would be used to remove VOCs from the groundwater in the cis-1 ,2-DCE plume and reduce concentrations to below the PRGs. Air sparging is a technology in which air is injected into the subsurface through sparge points. The injected air acts to remove or "strip" the VOCs from the groundwater. A grid of sparge points would be installed in areas of slow moving groundwater-relatively far from the pumping well (Maunabo #1) and a row of sparge points (a sparge curtain) would be installed closer to the well in the faster moving groundwater. Each sparge point is assumed to have a 10-foot radius of influence. This configuration is considered to be cost- and performance-optimized compared to a configuration consisting solely of a grid of sparge points across the entire plume.

This alternative also includes a SVE system. The SVE system would be implemented to collect the VOCs stripped from groundwater by the sparge system. It should be noted that since concentrations in groundwater are low, it is anticipated that the mass collected by the SVE system would be very low and potentially below detection limits in the SVE system effluent. Furthermore, biodegradation from the aerobic conditions created by the air sparging would further decrease the mass of cis-1 ,2-DCE to be captured by the SVE system.

26

R2-0002586

An air sparging/SVE system pilot test would be required to determine the radius of influence of each sparge location and soil vapor extraction well, and consequently the number of sparge points needed. The pilot test would also evaluate the need for treatment of the collected vapors.

Data obtained during the RI, pre-design MNA investigation, and air sparging/SVE system pilot test would be used to develop the detailed approach for site remediation during the remedial design. All aspects necessary for implementing the remedial action would be considered, including but not limited to: detailed layout of the treatment strategy and system, construction sequence, regulatory requirements, and cost estimates.

It is anticipated that the sparge grid would be operated for one year and the sparge curtain for three years. Performance monitoring would be conducted at groundwater monitoring wells installed in the sparge grid as well as upgradient and downgradient of the sparge curtain.

Pre-design MNA investigation, institutional controls, long-term monitoring, and fiveyear review components are similar to the ones described in Alternatives 1 and 2.

Alternative 4: In-situ Bioremediation (for the cis-1,2-DCE plume) and Monitored Natural Attenuation (for the PCE and 1,1-DCE plumes) Under this alternative, in-situ bioremediation could be implemented within the 70 J..LgiL contour in the cis-1,2-DCE plume, with institutional controls for protection of human health. In the PCE and 1,1-DCE plumes, MNA would be relied upon to ensure that the groundwater remediation RAO is met, as described in Alternative 2.

As part of the bioremediation alternative, a microcosm study would be conducted to better understand the natural biological activity within the plume and the effects of amendments on the microbes' ability to reduce contaminant concentrations. The microcosm study would evaluate the effectiveness of an amendment called EHC® and others such as lactate/whey in order to select the most cost-effective amendment(s) for this Site. A pilot study may need to be conducted prior to the remedial design to obtain site-specific design parameters for the full scale implementation of bioremediation. A pre-design investigation would be conducted to further delineate the vertical and lateral extent of the treatment zone in the plume. In-situ bioremediation of the cis-1,2-DCE plume would be conducted by injecting the selected amendment(s) in the form of bio-barriers, into a series of injection points over the target treatment area, which will be delineated during the pre-design MNA investigation. The amendment can be injected using direct push technology or permanent injection points. Based upon the low concentrations of the contaminants, only one round of amendment injection may be necessary. The reducing conditions created by the amendment injection would be expected to potentially enhance natural attenuation of remaining low concentration contaminants in the vicinity of treatment. Pre-design MNA investigation, institutional controls, long-term monitoring, and fiveyear review components are similar to the ones described in Alternatives 1 and 2.

27

R2-0002587

There are several common elements which would be included as part of each remedial alternative. The common elements include the items below.

• Long-Term Monitoring - Periodic monitoring of Site groundwater can be implemented when contaminants remain above levels that allow for unrestricted use and unlimited exposure. The monitoring program should continue until concentrations have stabilized or met remedial goals.

• Institutional controls -Institutional controls should restrict the future use of the groundwater, and should require precautions to be taken to protect human health in the event remedial measures are disturbed.

• Five-year site review - As discussed above, according to CERCLA, alternatives resulting in contaminants remaining above levels that allow for unrestricted use and unlimited exposure require that the Site be reviewed at least once every five years. If justified by the review, additional remedial actions may be implemented to remove, treat, or contain the contamination. The Site review would include a Site-wide visual inspection and a report prepared by EPA.

COMPARATIVE ANALYSIS OF ALTERNATIVES

Nine Superfund evaluation criteria were used to evaluate and compare the different remedial alternatives individually and against each other in order to select the best alternative. These nine evaluation criteria address statutory requirements and considerations for remedial actions in accordance with the NCP (40 C.P.R. 300.430(e)(9)) and additional technical and policy considerations that have proven to be important for selecting among remedial alternatives.

Each alternative has been evaluated against these nine criteria and compared to the other alternatives under consideration. The evaluation of the alternatives in relation to the nine criteria is discussed below.

Overall Protection of Human Health and the Environment Alternative 1 would not meet the RAOs and would not be protective of human health and the environment since no action would be taken. Contamination would remain in the groundwater, while no mechanisms would be implemented to prevent exposure to contaminated groundwater, or to reduce the toxicity, mobility, or volume of contamination except through natural attenuation processes, which would not be monitored to assess the effectiveness or predict the duration of this alternative. Alternative 2 would meet the RAOs. It is important to note that although historical data in Maunabo #1 has not shown contaminants above the MCLs since 2006, the cis-1,2-DCE plume is within the capture zone ofMaunabo #1. If natural attenuation does not occur within a reasonable time frame, there is the potential that the concentrations above the PRGs that are currently present in the plume would enter the Maunabo # 1 in the future, potentially impacting human health. Additional data collection would be needed to confirm that concentrations are decreasing through natural attenuation and the PRGs would be met within a reasonable timeframe. Similarly for the PCE and 1, 1-DCE plume, it is uncertain if natural attenuation is occurring at a great enough rate to permanently reduce concentrations to below the PRGS within a

28

R2-0002588

reasonable timeframe. Alternatives 3 and 4 will meet the RAOs. The air sparging and soil vapor extraction system for Alternative 3 and the bio-barriers in Alternative 4 would each serve to reduce the concentration of contaminants in groundwater being drawn into the Maunabo #1, providing protection of human health. Only bio-amendments that are safe to be injected into the aquifer near a public supply well would be considered and further evaluated during the microcosm study. Alternatives 2, 3, and 4 would provide adequate control of risk to human health by implementing institutional and engineering controls.

Compliance with Applicable or Relevant and Appropriate Requirements ("ARARs") Alternative 1 would not achieve chemical-specific ARARs established for groundwater. Location and action-specific ARARs do not apply to this alternative since no remedial action would be conducted. For Alternative 2, further data collection would be needed to confirm the ability of natural attenuation to reduce concentrations and comply with ARARs. If natural attenuation does not occur within a reasonable time frame, ARARs would not be met. This is true also ofthe PCE and 1,1-DCE plumes for Alternatives 3 and 4. For the cis-1,2-DCE plume, these two alternatives would meet the chemical-specific ARARs over the long-term because implementation of air sparging and soil vapor extraction system or in-situ treatment processes would be designed to significantly reduce contaminant concentrations in the treatment area. There are no location-specific ARARs for this Site. Alternatives 2 through 4 would comply with action-specific ARARs if implementation occurs as anticipated.

Long-Term Effectiveness and Permanence Alternative 1 would not be effective or permanent since there would be no mechanisms to prevent exposure to contaminated groundwater. Alternative 2 would provide long-term effectiveness and permanence by relying on natural attenuation to permanently reduce contaminant concentrations in the three plumes. However, for the cis-1,2-DCE and 1,1-DCE plumes, it is uncertain if natural attenuation is occurring at a great enough rate to reduce concentrations to below the PRGs within a reasonable timeframe. Alternatives 3 and 4 differs from Alternative 2 in that these alternatives would provide long-term effectiveness and permanence in the cis-1 ,2-DCE plumes by using in-situ treatment to reduce the contaminant mass in the treatment area. Alternatives 3 and 4 would provide the greatest permanent mass reduction of contamination within the cis-1,2-DCE plume within the shortest period of time. Remaining low contaminant concentrations in all three plumes would be reduced through natural attenuation processes. Institutional controls in Alternatives 2, 3 and 4 would prevent exposure to contaminated groundwater while groundwater quality is restored via natural attenuation processes. The long-term effectiveness of the selected alternative would be assessed through routine groundwater monitoring and five year reviews.

Reduction of Toxicity, Mobility, or Volume Through Treatment Alternative 1 would not reduce the contaminant toxicity, mobility, or volume ("T/MIV") since no remedial action would be conducted. For Alternative 2, the total volume of contaminated groundwater in all three plumes might increase if natural attenuation processes are unable to contain the plume. The extent and effectiveness of toxicity reduction pathways via natural attenuation, especially on-going biodegradation of chlorinated contaminants, would need to be verified with further data collection. Alternatives 3 and 4 would be the most effective in reducing toxicity and volume of

29

R2-0002589

contamination through treatment in the cis-1,2-DCE plume. Furthermore, the sparge curtain (Alternative 3) and bio-barriers (Alternative 4) would serve to limit the mobility of the cis-1,2-DCE plume beyond its existing footprint. In the 1,1-DCE plume, mobility would not be reduced via Alternative 3 or 4. However, toxicity and volume would potentially be reduced by biodegradation. T/M/V would not be reduced in the PCE plume since the mechanisms of natural attenuation would be dilution and dispersion, and not biodegradation.

Short-Term Effectiveness With respect to Alternative 1, there would be no short-term impact to the community and environment as no remedial action would occur. For long-term monitoring to be conducted on private property, coordination and access would need to be obtained from private property owners. There would be short-term impacts to the local community and workers for Alternatives 3 and 4 in the cis-1,2-DCE plume due to the active remedial actions undertaken and associated construction, operation, and/or injection activities. Implementing MNA in the PCE plume and I, 1-DCE plume would not be effective in the short term, since effectiveness would rely upon the dilution and dispersion created by groundwater flow and naturally occurring biodegradation to reduce concentrations to PRGs. Air monitoring, engineering controls, and appropriate worker Personnel Protective Equipment would be used to protect the community and workers for Alternatives 2 through 4.

Implementability Alternative 1 would be easiest both technically and administratively to implement as no additional work would be performed at the Site. Alternatives 2 through 4 would be technically implementable since services, materials, and experienced vendors are readily available. Bench and pilot studies would be implemented to obtain Site-specific design parameters. Access agreements would be required to implement the selected alternative on private properties. Overall, Alternative 4 would be the most difficult to implement, followed by Alternative 3, then Alternative 2.

Cost There are no costs associated with Alternative 1. The total present worth for Alternative 2 is $2.5 million. The total present worth for Alternative 3 is $4.9 million. The total present worth for Alternative 4 is $2.8 million.

State/Support Agency Acceptance The Commonwealth of Puerto Rico concurs with the selected remedy (Appendix II).

Community Acceptance Community acceptance of the selected remedy was assessed during the public comment period (August 9, 2012 to September 7, 2012). EPA believes that the community generally supports the selected remedy. Specific responses to public comments are addressed in the Responsiveness Summary (refer to Part III).

30

R2-0002590

PRINCIPAL THREAT WASTES

Principal threat wastes are those source materials considered to be highly toxic or highly a mobile that generally cannot be reliably contained, or would present significant risk to environment human health or the environment should exposure occur. The principal threat concept is applied to the characterization of source materials at a Superfund site. A source material is material that includes or contains hazardous substances, pollutants, or contaminants that act as a reservoir for migration of contamination to groundwater, surface water or air, or acts as a source for direct exposure. Contaminated groundwater generally is not considered to be a source material. Since the principal problem at Site is the presence of three groundwater contamination plumes; a cis-1,2-DEC plume, a PCE plume, and a 1, 1,-DCE plume, no principal threat is considered to exist at the Site.

SELECTED REMEDY

The selected remedy for the Site is Alternative 3: Air Sparging/Soil Vapor Extraction (for the cis-2,2-DCE plume) and Monitored Natural Attenuation (for the PCE and 1,1-DCE plumes). The selected remedy will achieve the RAOs established for the Site by reducing the groundwater contamination to the established PRGs and in accordance with the statutory determinations.

The selected remedy consists of the following major components: • Pre-design MNA investigation • Air sparging pilot study • Remedial design • Air sparging/SVE system • Institutional controls • Long-term monitoring • Five-year review

Pre-Design MNA Investigation To address the uncertainty surrounding contaminant concentration reduction via MNA, an MNA investigation will be performed in order to provide information to better project the effectiveness of natural attenuation mechanisms at field scale and to confirm that active degradation of contaminants is occurring where needed. The investigation will incorporate extensive monitoring within, at the boundaries, and downgradient of the capture zones. The pre-design MNA investigation will be conducted for a sufficient period of time to observe meaningful trends (i.e., several years) decision points, and contingency plans will be included so that any unexpected increase in contaminant concentrations or off-Site migration of contamination can be quickly addressed. The key to the effectiveness of MNA is the ability of natural processes to reduce contaminant concentrations to acceptable levels in a reasonable time frame. Factors that may limit the applicability and effectiveness of the process include the need to collect data, the need for highly skilled data evaluators, and limiting natural attenuation to low risk situations.

31

R2-0002591

Air Sparging/SVE System Pilot Study A pilot test will be performed to determine the radius of influence of each sparge location and soil vapor extraction well, and consequently the number of sparge points needed. The pilot test will also evaluate the need for treatment of the collected vapors.

Remedial Design Data obtained during the RI, pre-design MNA investigation, and air sparging/SVE system pilot study will be used to develop the detailed approach for Site remediation during the design. All aspects necessary for implementing the remedial action will be considered, including, but not limited to, detailed layout of the treatment strategy and system, construction sequence, regulatory requirements, and cost estimates. It is anticipated that the sparge points will have a 1 0-foot radius of influence, and SVE system wells will have a 20-foot radius of influence.

Air Sparging/SVE System Installation/Operation The air sparge curtain would be installed upgradient of Maunabo #1, and a grid of sparge points would be installed in the upgradient portion of the cis-1 ,2-DCE plume. SVE system wells would be installed to collect sparged vapors in the vadose zone. There would likely be no need to treat the vapor prior to release to the atmosphere because discharge rates could be lower than Puerto Rico standards; however, the need for vapor treatment should be evaluated thoroughly during remedial design. We estimated that the sparge grid would be operated for one year and the sparge curtain for three years. Performance monitoring would be conducted at groundwater monitoring wells installed in the sparge grid as well as upgradient and downgradient of the sparge curtain.

Institutional Controls This alternative will also involve implementation of institutional controls to control, limit, and monitor activities on-Site. The objectives of institutional controls will be to prevent prolonged exposure to contaminant concentrations, control future development, and prevent the installation of wells within the contaminated plume boundary. The effectiveness of selected institutional controls will depend on their continued implementation. The types of institutional controls employed in the plume footprint will include activity and use restrictions enacted through proprietary (e.g., easements, covenants) and/or governmental (e.g., zoning requirements) controls to prevent use ofthe properties that would pose an unacceptable risk to receptors (i.e., for residential use). Other institutional controls could include restrictions on installation of drinking water or irrigation wells, restrictions on groundwater use at locations within the plume footprint, and restrictions on home or building construction within the plume footprint. Institutional controls (e.g., warning signs, advisories, additional public education, deed notices, notices of environmental contamination) could also be employed to limit access to contaminated groundwater.

Long-Term Monitoring Monitoring is an essential component of engineered air sparging/SVE system design and operation. Post-construction long-term monitoring is critical to ensure that the sparge curtain and grid are removing contaminants from the groundwater plume as planned. Since contaminants would remain on-Site, a long-term groundwater monitoring program would be instituted to monitor groundwater contaminant concentrations and movement on

32

R2-0002592

Site. Groundwater samples from the monitoring well network would be collected annually and analyzed for COPCs. The monitoring data would be evaluated and used to assess the effectiveness of the selected remedy and to plan for further remedial action if required.

Five-Year Reviews Five-year review will be conducted every five years using data obtained from maintenance and monitoring program. These reviews are important under this alternative because it is an additional mechanism to ensure the protection of human health and the environment. In this FS, it is assumed that the review will be conducted six times for the duration of 30 year FS evaluation period.

Estimated Outcomes of Selected Remedy The principal outcome of the selected remedy is the restoration of the groundwater to the established PRGs, resulting on an improvement of a potable water supply for over 14,000 residents in the municipality of Maunabo.

EPA Region 2 Clean and Green Policy Consistent with EPA Region's 2 "Clean and Green" Policy, the utilization of applicable green remediation practices would be considered and, to the extent practical, would be incorporated into the detailed design of the selected remedy. Some examples of the operational practices that would be applicable are those that reduce emissions of air pollutants, minimize water consumption, incorporate native vegetation into revegetation plans, and consider beneficial reuse and/or recycling of materials, among others.

STATUTORY DETERMINATIONS

As required under Section 121 of CERCLA, remedial actions carried out under Section 104 or secured under Section 106 must be protective of human health and the environment and attain the levels or standards of control for hazardous substances, pollutants, or contaminants specified by the ARARs of Federal environmental laws and Commonwealth environmental and facility siting laws, unless waivers are obtained. The selected remedy also must be costeffective and utilize permanent solutions and alternatives treatment technologies or resource recovery technologies to the maximum extent practicable. Finally, the statute includes a preference for remedies that employ treatment that permanently and significantly reduce the volume, toxicity, or mobility of hazardous substances, as available.

Protection of Human Health and the Environment The selected remedy will provide protection of human health and the environment. The air sparging/soil vapor extraction system will remove the contaminants within the cis-1,2-DCE plume permanently. The remaining very low contaminant concentrations are expected to be reduced through natural processes such as dilution, dispersion, and biodegradation. During remediation, exposure to groundwater in all three plumes-beyond the exposure route of the existing supply wells-would be prevented through institutional controls. This remedy would meet the RAOs. Institutional controls would eliminate the exposure pathway for contaminated groundwater to local receptors before the RAOs and the PRGs are achieved.

33

R2-0002593

Compliance with ARARs The selected remedy would not meet chemical-specific ARARs in the short term in the PCE and 1, 1-DCE plumes because concentrations of COPCs would continue to exceed the PRGs in groundwater while natural attenuation is taking place. However, over time in all three plumes, the existing concentrations of COPCs are anticipated to decrease to acceptable levels within a reasonable timeframe by either the air sparging/SVE system or natural attenuation. If natural attenuation is not proceeding effectively, a contingency remedy would need to be implemented to meet chemical-specific ARARs. This alternative would follow health and safety requirements to meet the action-specific ARARs. There are no location-specific ARARs for this Site.

EPA defined three classifications of requirements in the ARAR determination process, defined as chemical-, location-, or action-specific. Additionally, TBC criteria are also evaluated.

Chemical-specific ARARs and TBCs Chemical-specific ARARs include those laws and regulations governing the release of materials possessing certain chemical or physical characteristics, or containing specified chemical compounds. These ARARs and TBCs usually are numerical values that are health- or risk-based values or methodologies. They establish acceptable amounts or concentration of chemicals that may be found in, or discharged to, the ambient environment. They also may define acceptable exposure levels for a specific contaminant in an environmental medium. They may be actual concentration-based cleanup levels, or they may provide the basis for calculating such levels. Examples of chemical-specific ARARs are polychlorinated biphenyl cleanup criteria for soils under the Toxic Substances and Control Act or Maximum Contaminant Levels (MCLs) specified for public drinking water that are applicable to groundwater aquifers used for drinking water.

Location-specific ARARs and TBCs Location-specific ARARs are design requirements or activity restrictions based on the geographical or physical positions of the Site and its surrounding area. Location-specific requirements set restrictions on the types of remedial activities that can be performed based on Site-specific characteristics or location. Examples include areas in a floodplain, a wetland, or an historic site. Location-specific criteria can generally be established early in the RifFS process since they are not affected by the type of contaminant or the type of remedial action implemented.

Action-specific ARARs and TBCs Action-specific ARARs are technology-based, establishing performance, design, or other similar action specific controls and restriction to particular remedial actions. These action-specific ARARs are considered in the screening and evaluation of various technologies and process options to be used as a remedy for a site.

The selected remedy will comply with the following ARARs and TBC guidelines identified for the Site and would be demonstrated through monitoring, as appropriate.

34

R2-0002594

Chemical-Specific

Under Federal Standards and Guidelines:

ARARs • Federal Drinking Water Standards and

Regulations is the National Primary Drinking Water Standards: MCLs (40 C.F.R. 141). This ARAR establishes healthbased standards for public drinking water systems. Also establishes drinking water quality goals set at levels at which no adverse health effects are anticipated, with an adequate margin of safety.

Under Commonwealth of Puerto Rico Standards and Guidelines:

• There is not a chemical-specific ARAR or TBC identified for this Site.

ARARs and TBCs for the Site

Location-Specific


• There is not a location-specific ARAR or TBC identified for this Site


• There is not a location-specific ARAR or TBC identified for this Site

35

Action-Specific


ARARs For Site Remediation • Occupational Safety and Health

Administration (OSHA) Worker Protection (29 C.F.R. 1904, 1910,1926)

• OSHA General Industry Standards (29 C.F.R. 1910)

• OSHA Construction Industry standards (29 C.F.R. 1926)

• Resource Conservation and Recovery Act (RCRA): Identification and Listing of Hazardous Waste (40 C.F.R. 261)

• Standards Applicable to Generators of Hazardous Waste (40 C.F.R. 262)

• Standards for Owners/Operators of permitted hazardous waste facilities ( 40 C.F.R. 264.10-264.19)

For Transportation of Hazardous Waste • Department of Transportation (DOT) Rules

for Transportation of Hazardous Materials (49 C.F.R. 107, 171, 172, 177, and 179)

• RCRA Standards Applicable to Transporters of Hazardous Waste (40 C.F.R. 263)

For Waste Disposal • RCRA Land Disposal Restrictions ( 40

C.F.R. 268) • RCRA Hazardous Waste Permit Program

R2-0002595

(40 C.F.R. 270) For Off-Gas Management

• Clean Air Act (CAA) -National Ambient Air Quality Standards (NAAQS) (40 C.F.R. 50)

• Standards of Performance for New Stationary Sources (40 C.F.R. 60)

• National Emission Standards for Hazardous Air Pollutants (40 C.F.R. 61)

TBCs For Off-Gas Management

• Federal Directive- Control of Air Emissions from Superfund Air Strippers (OSWER Directive 9355.0-28)


ARARs For Site Remediation

• PREQB Regulation for the Prevention and Control ofNoise Pollution Waste Disposal

• PREQB Regulation for the Control of Non-Hazardous Solid Waste (November 1997)

• PREQB Regulation for the Control of Hazardous Solid Waste (September 1998)

TBCs For Off-Gas Management

• PREQB Regulation for the Control of Atmospheric Pollution (1995)

36

R2-0002596

Cost Effectiveness A cost effective remedy is one whose costs are proportional to its overall effectiveness (NCP §§300.430(f)(l)(i)(B)). Overall effectiveness is based on the evaluations of the following: long-term effectiveness and permanence; reduction in toxicity, mobility, and volume through treatment; and short term effectiveness. Based on the comparison of overall effectiveness to cost, the selected remedy meets the statutory requirement that Superfund remedies be cost effective (NCP §§300.430(f)(l)(ii)(D)).

The selected remedy has undergone a detailed cost analysis. The total present worth for the selected remedy is around $4.9 million. The estimated capital cost is $2.3 million for the first five years, the estimated Operation and Maintenance and Long-Term Monitoring approximately $2.6 million for 30 years. A detailed cost estimate for the selected remedy is illustrated below.

Air Sparging and Soil Vapor Extraction System Extended Cost ($)

CAPITAL COSTS 1. Pre-design Investigation 486,000 2. Remedial Design 506,120 3. Air Sparging/Soil Vapor Extrusion System 927,000

Subtotal 1,919,120 Contingency (20%) 383,824

TOTAL COSTS 2,302,944

OPERATION & MAINTENANCE (O&M) COSTS 1. O&M- sparge grid (1 year) 268,734 2. O&M - sparge curtain ( 5 years) 79,300

TOTAL COSTS 348,034

LONG-TERM MONITORING {O&M) COSTS Long-term Monitoring (Quarterly year 1 and 2; Annually year 3-30) 126,000

TOTAL COSTS 229,000

PRESENT WORTH OF 30 YEAR COSTS (with discounting) 1. Total Capital Costs 2,302,944 2. Operation and Maintenance· 593,880 3. Long-term Monitoring Cost (30-years)" 2,098,449

TOTAL PRESENT WORTH OF 30 YEAR COSTS 4,995,273

TOTAL ESTIMATED REMEDY COST 4,995,273

* Present worth calculation assumes 7% discount rate after mflatron IS considered.

Utilization of Permanent Solutions and Alternative Treatment Technologies to the Maximum Extent Practicable The selected remedy represents the most appropriate solution at the Site because it provides the best balance oftradeoffs among the alternatives with respect to the evaluation criteria.

-37-

R2-0002597

The selected remedy combines a well-demonstrated approach (air sparging/SVE system) to remediation of contaminated groundwater that will provide a permanent remedy for contaminated groundwater. Air sparging protects human receptors by reducing concentrations of contaminants in groundwater. This technology is effective for volatile, relatively insoluble organics. Air flow through the saturated zone may not be uniform, which implies that there can be uncontrolled movement of potentially dangerous vapors. Depending on the mass of sparged vapors, air sparging could increase exposure to surface receptors if not implemented in conjunction with the SVE system.

EPA has concluded that the selected remedy is protective, compliant with ARARs, cost effectiveness, and provides the best balance of tradeoffs for utilizing permanents solutions and alternative treatment technologies to the extent practicable for the Site.

Preference for Treatment as a Principal Element The statutory preference for remedies that employ treatment as a principal element is satisfied through the implementation of the selected remedy. Air sparging involves the injection of air or oxygen into the contaminated aquifer. Injected air strips organic contaminants in-situ and helps to flush the contaminants into the unsaturated zone. If the mass of VOCs is great enough, soil SVE system may be implemented in conjunction with air sparging to remove the vapor-phase contamination from the vadose zone by vacuum extraction and, if required, vapor treatment to mitigate impacts to surface receptors. The need for an SVE system is generally determined during a site-specific pilot study. Oxygen in the air injected into contaminated groundwater can also enhance aerobic biodegradation of contaminants below and above the water table. This treatment technology accomplishes the required end result of protection human health and the environment.

Five Year Review Requirements Because the selected remedy results in contaminants remaining on-Site above levels that allow for unrestricted use and unlimited exposure, a review of Site conditions would be conducted no less often than every five years after completion of the construction of the remedy. The Site reviews will include an evaluation of the remedy components to ensure that the remedy remains protective of human health and the environment.

DOCUMENTATION OF SIGNIFICANT CHANGES FROM PREFERRED ALTERNATIVE OF PROPOSED PLAN

The Proposed Plan for the Site was released for public comment on August 9, 2012, and the public comment period ran from that date through September 7, 2012. The Proposed Plan identified the selected remedy as the Preferred Alternative for the Site.

All written and verbal comments submitted during the public comment period were reviewed by EPA. Upon review of these comments, EPA has determined that no significant changes to the remedy, as it was originally identified in the Proposed Plan, were necessary.

-38-

R2-0002598

APPENDIX I

Administrative Record Index for Maunabo Groundwater Contamination Superfund Site

-39-

R2-0002599

FINAL

08/08/2012 Region ID: 02

Site Name: MAUNABO URBANO PUBLIC WELLS

CERCLIS: PRN000205831

OUID: 01

1111111111111111111111111111111111111111

124190 SSID: 02XF

Action:

Region ID: 02

Doc ID: 124190

Bates:

Date: 07/1912012

Pages: 9

To:

Title: ADMINISTRATIVE RECORD INDEX FOR OU1 FOR THE MAUNABO URBAN PUBLIC WELLS SITE

Doc Type: INDEX

Name Author: ,

Name

Region ID: 02

Doc ID: 124179

Bates: R2-0000001

Date: 0110111111

Pages: 11

Organization US ENVIRONMENTAL PROTECTION AGENCY

Organization

To: R2-0000011

Title: MAUNABO AREA GROUNDWATER PRESENTATION FOR THE MAUNABO URBAN PUBLIC WELLS SITE

Doc Type: OTHER MAP

Name

Name

0810812012

Organization

Organization

Page 1 of 9

R2-0002600

Region ID: 02

Doc ID: 124181

FINAL

08/08/2012


CERCUS: PRN000205831

OUID: 01

SSID: 02XF

Action:

Bates: R2-0000012

Date: 0211912008

To: R2-0000172

Pages: 161

Region ID: 02

Title: FINAL WORK PLAN FOR THE REMEDIAL INVESTIGATION I FEASIBILITY STUDY FOR THE MAUNABO URBAN PUBLIC WELLS SITE

Doc Type: PLAN

Name Author: ,

Name Addressee: ,

Region ID: 02

Doc ID: 124188

Bates: R2-0000173

Date: 02/1912008

Pages: 2

Organization CDM FEDERAL PROGRAMS CORP


To: R2-0000174

Title: TRANSMITTAL OF THE FINAL WORK PLAN FOR THE REMEDIAL INVESTIGATION I FEASIBILITY STUDY FOR THE MAUNABO URBAN PUBLIC WELLS SITE

Doc Type: LETTER

Name Author: LITWIN, JEANNE

Name Addressee: ONEILL, CARLOS

0810812012

Organization CDM FEDERAL PROGRAMS CORP

Organization EPA

Page 2 of 9

R2-0002601

Region ID: 02

Doc ID: 124180

FINAL

08/08/2012



QUID: 01

SSID: 02XF

Action:

Bates: R2-0000175

Date: 01/28/2010

To: R2-0000750

Pages: 576

Region 10: 02

Title: QUALITY ASSURANCE PROJECT PLAN FOR THE REMEDIAL INVESTIGATION I FEASIBILITY STUDY FOR THE MAUNABO URBAN PUBLIC WELLS SITE

Doc Type: PLAN

Name Author: ,

Name Addressee: ,

Region 10: 02

Doc ID: 124187

Bates: R2-0000751

Date: 01/28/2010

Pages: 2

Organization COM FEDERAL PROGRAMS CORP


To: R2-0000752

Title: TRANSMITTAL OF THE FINAL QUALITY ASSURANCE PROJECT PLAN FOR THE REMEDIAL INVESTIGATION /A FEASIBLITY STUDY FOR THE MAUNABO URBAN PUBLIC WELLS SITE

Doc Type: LETTER

Name Author: VALENTINO, MICHAEL

Name Addressee: SANTOS, LUIS

08/08/2012

Organization COM FEDERAL PROGRAMS CORP

Organization EPA, REGION 2

Page 3 of 9

R2-0002602

Region ID: 02

Doc ID: 124178

FINAL

08/08/2012



OUID: 01

SSID: 02XF

Action:

Bates: R2-0000753

Date: 04/27/2012

To: R2-0000836

Pages: 84

Region ID: 02

Title: FINAL SCREENING LEVEL ECOLOGICAL RISK ASSESSMENT FOR THE MAUNABO URBANO PUBLIC WELLS SITE

Doc Type: REPORT

Name Author: ,

Name

Region ID: 02

Doc ID: 124186

Bates: R2-0000837

Date: 04/27/2012

Pages: 1

Organization COM SMITH

Organization

To: R2-0000837

Title: TRANSMITTAL OF THE FINAL SCREENING LEVEL ECOLOGICAL RISK ASSESSMENT FOR THE REMEDIAL INVESTIGATION I FEASIBILITY STUDY FOR THE MAUNABO URBAN PUBLIC WELLS SITE

Doc Type: LETTER



08/08/2012



Page 4 of 9

R2-0002603

Region ID: 02

Doc ID: 124182

FINAL

08/08/2012



OUID: 01

SSID: 02XF

Action:

Bates: R2-0000838

Date: 05/04/2012

To: R2-0000843

Pages: 6

Region 10: 02

Title: RESPONSE TO COMMENTS ON THE DRAFT REMEDIAL INVESTIGATION REPORT FOR THE MAUNABO URBAN PUBLIC WELLS SITE

Doc Type: OTHER

Name Author: ,

Name

Region ID: 02

Doc ID: 124189

Bates: R2-0000844

Date: 05/04/2012

Pages: 1

Organization CDMSMITH

Organization

To: R2-0000844

Title: TRANSMITTAL OF THE RESPONSE TO COMMENTS ON THE DRAFT REMEDIAL INVESTIGATION REPORT FOR THE MAUNABO URBAN PUBLIC WELLS SITE

Doc Type: LETTER



08/08/2012

Organization CDMSMITH


Page 5 of 9

R2-0002604

Region ID: 02

Doc ID: 660977

FINAL

08/08/2012



OUID: 01

SSID: 02XF

Action:

Bates: R2-0000845

Date: 06/29/2012

To: R2-0002066

Pages: 1222

Region 10: 02

Title: FINAL REMEDIAL INVESTIGATION REPORT FOR THE MAUNABO URBANO PUBLIC WELLS SITE

Doc Type: REPORT

Name Author: ,

Name Addressee: ,

Region 10: 02

Doc ID: 123469

Bates: R2-0002067

Date: 07/03/2012

Pages: 1

To: R2-0002067


Organization US ENVIRONMENTAL PROTECTION AGENCY REGION2

Title: TRANSMITTAL OF THE FINAL HUMAN HEALTH RISK ASSESSMENT REPORT FOR THE MAUNABO URBANO PUBLIC WELLS SITE

Doc Type: LETTER



08/08/2012



Page 6 of 9

R2-0002605

Region ID: 02

Doc ID: 123470

FINAL

08/08/2012



OUID: 01

SSID: 02XF

Action:

Bates: R2-0002068

Date: 07/03/2012

To: R2-0002360

Pages: 293

Region ID: 02

Title: FINAL HUMAN HEALTH RISK ASSESSMENT FOR THE MAUNABO URBANO PUBLIC WELLS SITE

Doc Type: REPORT

Name Author: ,

Name

Region 10: 02

Doc ID: 123500

Bates: R2-0002361

Date: 08/06/2012

Pages: 1

To: RZ-0002361


Organization

Title: TRANSMITIAL OF THE FINAL FEASIBILITY STUDY REPORT FOR THE MAUNABO URBANO PUBLIC WELLS SITE

Doc Type: LETIER

Name Author: ,


08/08/2012



Page 7 of 9

R2-0002606

Region ID: 02

Doc ID: 123499

FINAL

08/08/2012



OUID: 01

SSID: 02XF

Action:

Bates: R2-0002362

Date: 08/06/2012

To: R2-0002501

Pages: 140

Region ID: 02

Title: FINAL FEASIBILITY STUDY REPORT FOR THE MAUNABO URBANO PUBLIC WELLS SITE Doc Type: REPORT

Name Author: ,


Region ID: 02

Doc ID: 123502

Bates: R2-0002502

Date: 08/07/2012

Pages: 1

Organization CDM SMITH


To: R2-0002502

Title: US EPA NOTICE OF PUBLIC COMMENTS ON THE PROPOSED PLAN (SPANISH VERSION) FOR THE MAUNABO URBANO PUBLIC WELLS SITE

Doc Type: NOTICE

Name Author: ,

Name

08/08/2012


Organization

Page 8 of 9

R2-0002607

Region ID: 02

Doc ID: 123501

FINAL

08/08/2012



OUID: 01

SSID: 02XF

Action:

Region ID: 02

Bates: R2-0002503

Date: 08/07/2012

To: R2-0002525

Pages: 23

Title: PROPOSED PLAN FOR THE MAUNABO URBANO PUBLIC WELLS SITE

Doc Type: PLAN

Name Author: ,

Name

08/08/2012

Organization US ENVIRONMENTAL PROTECTION AGENCY REGION2

Organization

Page 9 of 9

R2-0002608

APPENDIX II

Puerto Rico Environmental Quality Board's Concurrence Letter

-40-

R2-0002609

GOBIEflN O OE PUERTO R ICO OFIC INA D EL GOBERNAOOR JUNTA DE CALl DAD AMBIENTAL

August 7, 2012

Mr. Jose C. Font Acting Division Director Caribbean Environmental Protection Division US EPA, Region 2 City View Plaza II - Suite 7000 48 RD. 165 Km. 1.2 Guaynabo, P.R. 00968-8069

Dear Mr. Font:

Oficina del Director Ejecutivo

The Puerto Rico Environmental Quality Board (PREQB) acknowledges receipt of the Proposed Plan for the Maunabo Ground Water Contamination Site dated August 2012. The Maunabo Ground Water Contamination Site is a National Priority List (NPL) Site being managed by the US Environmental Protection Agency (USEPA) responsibilities under Section 117(a) of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), as amended (commonly known as the federal "Superfund" law), and Section 300.430(f)(2) of the National Oil and Hazardous Substances Pollution Contingency Plan (NCP).

After the review of the documentation provided and due consideration of all the information available to us; the PREQB concurs with the preferred alternative recommendation for the Maunabo Ground Water Contamination Site. This alternative is identified as number (3) : Air SpargingjSoil Vapor Extrusion, Natural Attenuation, Long-term Monitoring, Institutional Controls and five year review.

If you have any question, please do not hesitate to contact Mrs. Nitza Marrero Fontan, Project Manager, at (787)502-2410 [email protected] or Carlos E. O'Neill at (787)767 -8056 [email protected].

r

Pet o . •~nda, Esq. Execu ive Director

c: Luis E. Santos - USEPA

"Puerto Rico es nuestro ambiente, cuidemoslo" Edificio de Agencias Arnbientales Cruz A. Matos - Ave. Ponce de Leon #1375. San Juan. PR

PO Box 11488 Santurce. PR 00910 I T. 787-767-8056 I F. 787-767-4861 www.jca.pr.gov

R2-0002610

APPENDIX III

Figures

-41-

R2-0002611

Figure 1 -Site Location

Public Supply Wells

Figure t-1 Site Ln:at1on Map

MaunabO Groundwater Contamination Site Maunabo, Puerto Rico

R2-0002612

Fig11re 2- Locatio11s ofthe Pl11mes

Esitmated MCL isocontour

Monitoring Well Locstlons *' Ground'wBter Screenlrtg_ loc&Jklns

Mavn®r>#1 Publrr:; Supp%}1 V\'el!s Uncertalnlsacontour Boundary

-43-

Figure 2-1 Plume Map- MCL (~gil) lsocontours

Maunabo Superfund Site Maunabo, Puerto Rico

R2-0002613

Fig11re 3- Groundwater Screening Investigation Sampling Locations (Transects)

Groundwater Sr:re,eni>ng locations

Groundwater nol encountered

-44-

figure 2-1 Groundvl3ter Screening Locations

Maunabo Groundwater Contamination Site M:mnabo, Puerto Rico

R2-0002614

MRL-70

TO- 2'1D

>-210

lfFEGG~~ci~-i,:Z-OCE 70 1.lf!ll iSOCOl)IOUr

SVE Wfrf!S

-45-

Figure 3-1 of AS/SVE System in cts- ,2-DCE Plume

Maunabo Groundwater Contamination Site Maunabo, Puerto Rico

R2-0002615

APPENDIX IV

Proposed l'hm and Fact Sheet (Spanish)

-46-

R2-0002616

EPA Region 2 – August 2012

INTRODUCTION This Proposed Plan (Plan) identifies the Preferred Alter-native for cleaning up the contaminated groundwater at the Maunabo Area Groundwater Contamination Super-fund Site (Site), Maunabo, Puerto Rico (Figure 1) and provides the rationale for this preference. In addition, this Plan includes summaries of other cleanup alternatives evaluated for use at this Site. This document is issued by the U.S. Environmental Protection Agency (EPA), the lead agency for Site activities, and the Puerto Rico Envi-ronmental Quality Board (EQB), the support agency. EPA, in consultation with EQB, will select a final remedy for the Site after reviewing and considering all infor-mation submitted during the 30-day public comment pe-riod. EPA, in consultation with EQB, may modify the Preferred Alternative or select another response action presented in this Plan based on new information or public comments. Therefore, the public is encouraged to review and comment on all the alternatives presented in this plan. The U.S. Environmental Protection Agency (EPA) is is-suing this Proposed Plan as part of its requirements under Section 117(a) of the Comprehensive Environmental Re-sponse, Compensation and Liability Act (CERCLA, commonly known as Superfund), and Section 300.430(f)(2) of the National Oil and Hazardous Sub-stances Pollution Contingency Plan. This Proposed Plan summarizes information that can be found in greater detail in the Remedial Investigation and Feasibility Study (RI/FS) reports and other documents contained in the Administrative Record (AR) for this Site. EPA and EQB encourage the public to review these documents to gain a more comprehensive understanding of the Site and Superfund activities that have been con-ducted there. SITE BACKGROUND The Maunabo Urbano public water system consists of four groundwater wells: Maunabo #1 through Maunabo #4. This system serves a population of approximately 14,000 people and is managed by the Puerto Rico Aque-

duct and Sewer Authority (PRASA). In 1961, PRASA installed the public water supply well Maunabo #1 and it was used until 1974 (Adolphson et al. 1977). In 2001, PRASA decided to reactivate the Maunabo #1 well. In 2002, PRASA conducted groundwater sampling which found the presence of chlorinated volatile organic compounds (VOCs), tetrachloroethene (PCE), trichloroethene (TCE), cis‐1,2‐dichloroethene (cis‐1,2 ‐DCE), and 1‐dichloroethene (1,1 ‐DCE). The maximum

MARK YOUR CALENDAR

PUBLIC COMMENT PERIOD:

August 9, 2012 – September 7, 2012

EPA will accept written comments on the Proposed Plan during the public comment period.

Written comments should be addressed to:

Luis E. Santos,

Remedial Project Manager United States Environmental Protection Agency Caribbean Environmental Protection Division

City View Plaza II – Suite 7000 48 RD. 165 Km. 1.2

Guaynabo, P.R. 00968-8069 Telephone: (787) 977-5824

Fax: (787) 289-7104 Emailt:[email protected]

PUBLIC MEETING:

August 23, 2012 at 7:00 pm

EPA will hold a public meeting to explain the Pro-posed Plan and all of the alternatives presented in the Feasibility Study. Oral and written comments will also be accepted at the meeting. The meeting will be held at the Maunabo City Hall.

Superfund Program U.S. Environmental Protection Agency Proposed Plan Region 2 Maunabo Groundwater Contamination Superfund Site Maunabo, Puerto Rico August 2012

R2-0002617

PROPOSE PLAN MAUNABO GROUNDWATER CONTAMINATION SUPERFUND SITE

2

concentrations of PCE, TCE, and cis‐1,2‐DCE detected in Maunabo #1 were 16.4 micrograms per liter (μg/L), 1.6 μg/L, and 4.3 μg/L, respectively. The federal maximum contaminant level (MCL) for PCE and TCE is 5 μg/L, and for cis‐1,2‐DCE is 70 μg/L. In addition, Maunabo #2, # 3, and #4 wells were sampled to determine the pres-ence of VOCs. Another VOC, 1,1‐dichloroethene (1,1 ‐DCE) was detected intermittently in subsequent years in both Maunabo #1 and Maunabo #4 at levels below the MCL. These VOCs were not present in samples collected from Maunabo supply wells #2 and # 3 over the same time period. Tap water samples of the distributed water showed that the contaminants detected in Maunabo #1 were present. In March 2002, the Puerto Rico Department of Health (PRDOH) ordered PRASA to close Maunabo #1 because the PCE concentration exceeded the federal MCL. How-ever, rather than close the well, PRASA opted to treat the groundwater at the wellhead using activated carbon filtra-tion tanks. Post‐treatment samples taken as part of a PRDOH 2004 inspection, including tap water samples collected from the distribution system down the line from Maunabo #1, indicated that PRASA's treatment was not effective and that contaminated drinking water was reaching the consumers. In October 2005, EPA’s Site Assessment Team (SAT) 2 collected water samples from Maunabo Wells #1, #2, #3, and #4, and in the distribution water system. The samples were analyzed for Target Compound List (TCL) organic parameters, base/neutral/acid, pesticides/polychlorinated biphenyls (PCBs) and Target Analyte List inorganic pa-rameters including mercury and cyanide through the EPA Contract Laboratory Program (CLP). The data confirmed the presence of PCE and cis‐1,2‐DCE in Maunabo #1 and in post‐treatment samples along the distribution line at levels below the MCLs. The results also confirmed the presence of 1,1 DCE in Maunabo #4 and a gasoline additive, methyltertbutylether (MTBE), in Maunabo #1 and in the distribution system samples. No detections were above the MCL, except for bis(2‐ethylhexyl) phthalate (6.5 μg/L) in Maunabo #3, which marginally exceeded the MCL of 6 μg/L. PCE, cis‐1,2‐DCE, 1,1‐DCE, and MTBE were not detected in Maunabo #2 and Maunabo #3. In December 2005, SAT 2 conducted a limited investiga-tion to identify possible sources of groundwater contami-nation in Maunabo. Facilities that were investigated in-clude the former Maunabo Municipal Solid Waste Land-

fill (Maunabo Landfill), PRASA's Wastewater Treatment Plant located close to Maunabo Well #1, El Negro Auto Body/Parts Shop, Total Gas Station, Esso Gas Station, and five light industrial facilities operating under the aus-pices of the Puerto Rico Industrial Development Corpora-tion (PRIDCO). The five identified PRIDCO industrial facilities are: Centro de Acopio Manufacturing; Juan Orozco Limited, Inc; Puerto Rico Beverage; FEMA Stor-age Facility; and Plastic Home Products. A summary of SAT 2 limited investigation activities and findings is presented below. All of the samples collected at the properties described below were analyzed for target compound list (TCL) VOCs through the EPA contract laboratory program (CLP).

Maunabo Landfill ‐ SAT 2 collected four sur-face soil samples, including one duplicate, one subsurface soil sample, and one groundwater sample at the former Maunabo Landfill. VOCs were not detected in the samples. No preliminary assessment/site inspection (PA/SI) report was prepared by SAT 2 for the landfill.

PRASA Wastewater Treatment Plant ‐ SAT collected four surface soil samples, two subsur-face soil samples, and one groundwater sample at the PRASA Wastewater Treatment Plant. VOCs were not detected in the samples. No PA/SI re-port was prepared for this facility.

El Negro Auto Body/Parts Shop ‐ SAT 2 con-ducted an on‐site reconnaissance of the facility. The facility was well maintained. One surface soil sample was collected from an open area ad-jacent to the facility. VOCs were not detected in the sample. SAT 2 had no detailed information regarding historical waste disposal practices at the facility. The PA/SI report for the facility rec-ommended no further remedial action.

Total Gas Station ‐ SAT 2 collected two groundwater samples at the Total Gas Station. MTBE, a gasoline additive, was detected at 14 and 7J μg/L in the samples Benzene was detected at 4J μg/L and 20 μg/L, which exceeded the MCL of 5 μg/L. SAT 2 did not prepare a PA/SI report for this facility.

Esso Gas Station ‐ SAT 2 collected three groundwater samples, including one duplicate, at the Esso Gas Station. No VOCs were detected in the samples. No PA/SI report was prepared for this facility.

Centro de Acopio Manufacturing ‐ SAT 2 col-lected four surface soil samples, two subsurface

R2-0002618


3

soil samples, and one groundwater sample from open areas adjacent to the Centro Acopio Manu-facturing (CAM) facility building using the Geoprobe™ direct‐push method. No VOCs were detected in the samples. A review of available background information indicated that these sub-stances were not generated by activities at the CAM facility, nor were any waste sources sus-pected of releasing or having the potential to re-lease contaminants to groundwater or surface wa-ter identified at the CAM facility. The PA/SI re-port recommended no further remedial action for the CAM facility.

Juan Orozco Limited, Inc. ‐ SAT 2 collected four surface soil samples, two subsurface soil samples, and one groundwater sample from open areas adjacent to the facility building using the Geoprobe™ direct-push method. Analytical re-sults indicated non‐detect values for contami-nants previously detected in the Maunabo public water supply wells as well as the remaining VOC parameters. A review of available background in-formation indicated that these substances were not generated by activities at Juan Orozco Lim-ited, nor were any waste sources suspected of re-leasing or having the potential to release contam-inants to groundwater or surface water identified at the facility. The PA/SI report recommended no further remedial action.

Puerto Rico Beverage ‐ SAT 2 collected four surface soil samples, two subsurface soil sam-ples, and one groundwater sample from open are-as adjacent to the Puerto Rico Beverage (PRB) facility building using the Geoprobe™ di-rect‐push method. No VOCs were detected in the samples. A review of available background in-formation indicated that VOCs were not generat-ed by activities at PRB, nor were any waste sources suspected of releasing or having the po-tential to release to groundwater or surface water identified at the PRB facility. The PA/SI report recommended no further remedial action for PRB.

FEMA Storage Facility ‐ SAT 2 collected five surface soil samples, including a duplicate sam-ple, and two subsurface soil samples from open areas adjacent to the FEMA Storage Facility us-ing the Geoprobe™ direct‐push method. No VOCs were detected in the samples.

Plastic Home Products ‐ SAT 2 collected four surface soil samples and two subsurface soil samples from open areas adjacent to the Plastic

Home Products (PHP) facility using the Geoprobe™ direct‐push method. No VOCs were detected in the samples. A review of available background information indicated that VOCs were not generated by activities at PHP, nor were any waste sources suspected of releasing or hav-ing the potential to release contaminants to groundwater or surface water identified at the PHP facility. The PA/SI report recommended no further remedial action for PHP.

SAT 2 collected four background surface soil, two back-ground subsurface soil, and one background groundwater sample. No VOCs were detected in the background sam-ples. Based on the October and December 2005 data, SAT 2 concluded that there was insufficient information to determine the source of contamination of the public supply wells. EPA completed a Hazard Ranking System Documenta-tion Package (HRS) in 2006. The Site was listed on the National Priorities List (NPL) on September 27, 2006.

EPA conducted a Remedial Investigation (RI) at the Site from August 2010 to July 2011. From August 25 through September 29, 2010, a groundwater screening investiga-tion was conducted at five potential source areas based on information provided in the Site Inspection and Hazard Ranking System Repor and a field reconnaissance con-ducted by CDM Smith. The groundwater screening inves-tigation was conducted to provide screening‐level data on the distribution of VOCs in groundwater. The screening data were used to support selection of the locations and depths of permanent monitoring wells and to identify po-tential source areas for subsequent soil sampling. Groundwater screening investigation samples were col-lected along four transects (Figure 2):

Transect 1 – East ‐ Potential Source Area Upgradient of Maunabo # 4

Transect 1‐ West ‐ PRIDCO Potential Source Ar-ea (including Puerto Rico Beverage [PRB])

Transect 2 ‐ Central Potential Source Area Transect 3 ‐ Northern Potential Source Area Transect 4 ‐ Former Sugar Mill Potential Source

Area Groundwater screening samples were collected along four transects oriented approximately perpendicular to the estimated groundwater flow direction. Groundwater screening samples were collected using a groundwater sampling system with a 4‐foot screen attached to a direct push technology. At each location, samples were collect-

R2-0002619


4

ed at 10-foot intervals, starting from the bottom of bore-hole and extending to the groundwater table. All screen-ing samples were analyzed for trace‐level VOCs with a 24‐hour turnaround time. A summary of the groundwater screening collected from the five source areas is provided below:

Transect 1 – East ‐ Southeastern Potential Source Area ‐ A total of 37 groundwater screen-ing samples, including duplicates, were collected from four locations downgradient from a residen-tial/commercial area and upgradient of Maunabo #4. Transect 1 – West ‐ PRIDCO Potential Source Area ‐ A total of 71 groundwater screen-ing samples, including duplicates, were collected from 10 locations downgradient from Centro de Acopio, Juan Orozco LTD, PRB and PRASA’s Waste Water Treatment Plant.

Transect 2 ‐ Central Potential Source Area ‐ A total of 10 groundwater screening samples, in-cluding duplicates, were collected from four lo-cations downgradient of the Esso Gas Station and Maunabo Dry Cleaners.

Transect 3 ‐ Northern Potential Source Area ‐ A total of 12 groundwater screening samples, in-cluding duplicates, were collected from four lo-cations downgradient from the Federal Emergen-cy Management Agency (FEMA) Storage Facili-ty, Plastic Home Products, and Total Gas Station. Transect 4 ‐ Former Sugar Mill (FSM) Poten-tial Source Area ‐ A total of 31 groundwater screening samples, including duplicates, were collected from four locations downgradient from the FSM facility, south of the Rio Maunabo.

From December 10 through 22, 2010, 64 additional groundwater screening samples, including duplicates, were collected and analyzed for VOCs. This groundwater screening supplemental sampling was conducted at nine additional locations. These additional locations were add-ed to provide the data to refine and focus the locations and depths for permanent monitoring wells, including background monitoring wells. Three groundwater monitoring wells were used to evalu-ate water quality upgradient of the impacted areas. Sedi-ment and surface water background samples were col-lected upriver from the expected zone of impact in the Rio Maunabo.

A total of 16 monitoring wells were installed as part of the RI. Two rounds of groundwater samples were collect-ed from the 16 monitoring wells and the four public sup-ply wells (Maunabo# 1 through Maunabo# 4). Round 1 was conducted between March 2 and 8, 2011. Round 2 was conducted between June 7 and 10, 2011. During the RI field investigation, groundwater background samples were collected from areas not expected to be impacted by site‐related contamination. These samples were analyzed for the same analytical parameters as previous sampling events. Based on the groundwater data collected during the RI, there are three separate plumes (cis-1,2-DCE, PCE, and 1,1,-DCE) at the Site (Figure 3). The plumes are located in different areas of the Site and have characteristic con-taminant profiles. The conclusions for each of the three plumes are: Cis-1,2-DCE Plume ‐ The configuration of this plume indicates that a release of site‐related contaminants, most likely PCE or TCE, occurred in or near the Puerto Rico Beverage (PRB) facility. Cis‐1,2‐DCE, a degradation product of TCE, was found at the highest concentrations (up to 300 μg/L) in this area. Related VOCs including trans‐1,2‐DCE, 1,1‐DCE, and vinyl chloride (VC) are also present, but at much lower concentrations. Only cis‐1,2‐DCE (up to 300 μg/L) and VC (up to 1.8 μg/L) exceed the groundwater screening criteria. Site-related groundwater contamination was not detected in ground-water upgradient of the PRB Area. The plume is migrat-ing toward the southwest, influenced by pumping at the Maunabo #1 supply well and groundwater flow toward the Rio Maunabo. PCE Plume – The primary contaminant in this plume near the Former Sugar Mill is PCE, which is present at concentrations exceeding screening criteria in one moni-toring well (8.5 J μg/L) and one screening location (7.4 μg/L). TCE was also detected, but concentrations were well below the screening criteria of 5 μg/L. The plume is migrating toward the northeast, influenced by pumping at the Maunabo #1 supply well and groundwater flow to-ward the Rio Maunabo. The downgradient edge of the plume is the Maunabo #1 supply well. 1,1,-DCE Plume – This plume is located northwest of Maunabo #4 and differs from other plumes in that it con-sists almost entirely of 1,1‐DCE. The highest concentra-tion of 1,1‐DCE detected was 25 μg/L in a monitoring well (MW-L). Also, 1,1‐DCE was detected in the Maunabo #4 supply well (1.1 μg/L). The plume appears

R2-0002620


5

to be migrating toward the southeast, toward Maunabo #4. However, the plume may also be migrating toward the southwest, influenced by groundwater flow toward the Rio Maunabo. The source of this plume is unknown. Surface and subsurface soil samples were collected at two potential source areas, the PRB Area and FSM Area. These areas were identified as potential source areas based on the groundwater screening results. A discussion of the results of the soil sampling is as follows: PRB Area – Surface and subsurface soil samples collect-ed from the PRB Area did not identify a source of site‐related VOCs. None of the six site‐related VOCs was detected in soil samples from the PRB Area. However, one Semi-Volatile Organic Compound (SVOC), bis(2‐ethylhexyl)phthalate, and several metals exceeded screening criteria. The SVOC and metals are not consid-ered to be site-related and are not affecting the public supply wells. FSM Area – Surface and subsurface soil samples col-lected from the FSM Area did not identify a source of site related VOCs. None of the six site‐related VOCs were detected in soil samples from the FSM Area. However, in surface soil samples, three SVOCs and 12 metals exceed-ed screening criteria, and one SVOC, benzo(a)pyrene, and eight metals exceeded their screening criteria in sub-surface samples. The SVOC and metals are not consid-ered to be site-related and are not affecting the public supply wells. Surface water, sediment, and porewater have not been impacted at the site since none of the six site‐related VOCs was detected samples collected from these media in the Rio Maunabo. No VOCs, SVOCS, pesticides, PCBs, or metals exceeded screening criteria in surface water or porewater samples. Six metals exceeded screen-ing criteria in sediment samples, but they are not consid-ered to be site-related.

SITE CHARACTERISTICS The Site is located in the municipality of Maunabo, in the southeastern coastal area of Puerto Rico (18° 00' 20.6" north latitude and 65° 54' 19.5" west longitude), within an isolated alluvial river valley (Figure 1). It is surrounded by mountains to the north, east, and west and the Carib-bean Sea to the southeast. The highest point in the area is Cerro La Pandura at 1,700 feet above mean sea level (amsl) and the lowest point is the Caribbean Sea to the southeast. The Maunabo River and several intermittent streams are located in the vicinity of the Site and flow to the southeast toward the Caribbean Sea. The area topog-raphy slopes south/southwest from the nearby hills, ap-proximately 180 feet amsl, toward the Maunabo River at 30 feet amsl. The elevation of the Site area is approxi-mately 40 feet amsl. The limits of the Pandura Sierra Mountain Range run through the north and northeast re-gion of Maunabo, in which the Pandura and El Sombrerito hills, at the border with Yabucoa, are the highest elevations. With the exception of the elevations noted above, the rest of the territory of Maunabo is quite level. As a result, it is geographically considered part of the Southern Coastal Valley. The Site consists of three groundwater plumes (cis-1,2-DCE; PCE; and 1,1,-DCE) with no identified source(s) of contamination (Figure 3). The Maunabo Urbano public water system consists of four groundwater wells: Maunabo #1 through Maunabo #4. Groundwater contam-ination was found in two of the public supply wells, Maunabo #1 and Maunabo #4. The four public supply wells are completed at depths ranging from 80 to 125 feet below the ground surface (bgs) in the Maunabo alluvial valley aquifer. This aquifer generally consists of poorly sorted sand, silt, clay, and gravel alluvium, including len-ticular deposits of sand, gravel, and cobbles.

R2-0002621


6

WHAT IS RISK AND HOW IS IT CALCULATED?

A Superfund baseline human health risk assessment is an analysis of the potential adverse health effects caused by hazardous substance releases from a site in the absence of any actions to control or mitigate these under current- and future-land uses. A four-step process is utilized for assessing site-related human health risks for reasonable maximum ex-posure scenarios. Hazard Identification: In this step, the contaminants of con-cern at the site in various media (i.e., soil, groundwater, sur-face water, and air) are identified based on such factors as toxicity, frequency of occurrence, and fate and transport of the contaminants in the environment, concentrations of the contaminants in specific media, mobility, persistence, and bioaccumulation. Exposure Assessment: In this step, the different exposure pathways through which people might be exposed to the con-taminants identified in the previous step are evaluated. Ex-amples of exposure pathways include incidental ingestion of and dermal contact with contaminated soil. Factors relating to the exposure assessment include, but are not limited to, the concentrations that people might be exposed to and the po-tential frequency and duration of exposure. Using these fac-tors, a “reasonable maximum exposure” scenario, which por-trays the highest level of human exposure that could reason-ably be expected to occur, is calculated. Toxicity Assessment: In this step, the types of adverse health effects associated with chemical exposures, and the relationship between magnitude of exposure (dose) and se-verity of adverse effects (response) are determined. Potential health effects are chemical-specific and may include the risk of developing cancer over a lifetime or other non-cancer health effects, such as changes in the normal functions of organs within the body (e.g., changes in the effectiveness of the immune system). Some chemicals are capable of causing both cancer and non-cancer health effects. Risk Characterization: This step summarizes and combines exposure information and toxicity assessments to provide a quantitative assessment of site risks. Exposures are evaluat-ed based on the potential risk of developing cancer and the potential for non-cancer health hazards. The likelihood of an individual developing cancer is expressed as a probability. For example, a 10-4 cancer risk means an “one-in-ten-thousand excess cancer risk”; or one additional cancer may be seen in a population of 10,000 people as a result of exposure to site contaminants under the conditions explained in the Exposure Assessment. Current Superfund guidelines for acceptable exposures are an individual lifetime excess cancer risk in the range of 10-4 to 10-6 (correspond-ing to a one-in-ten-thousand to a one-in-a-million excess cancer risk). For non-cancer health effects, a “hazard index” (HI) is calculated. An HI represents the sum of the individual exposure levels compared to their corresponding reference doses. The key concept for a non-cancer HI is that a “thresh-old level” (measured as an HI of less than 1) exists below which non-cancer health effects are not expected to occur.

The regional direction of groundwater flow in the Maunabo basin is to the southeast toward the Caribbean Sea. Wellhead Protection Areas are delineated for the public supply wells, so the groundwater plumes lie within a designated Wellhead Protection Area. SCOPE AND ROLE OF THE ACTION Groundwater contamination has been defined in suffi-cient detail to complete the RI Report and prepare a fea-sibility study and risk assessments. SUMMARY OF SITE RISKS As part of the Remedial Investigation and Feasibility Study, EPA conducted a baseline risk assessment to de-termine the current and future effects of contaminants on human health and the environment. The current exposure pathways and receptors evaluated are: Commercial Indus-trial Workers at Former Sugar Mill and Puerto Rico Bev-erage; Trespassers at Former Sugar Mill and Puerto Rico

Beverage; Residents at Former Sugar Mill; and Recrea-tional Users at Maunabo River. The future exposure

The administrative record file, which con-tains the information upon which the selection of the response action will be based, is available at the follow-ing locations: Maunabo City Hall Maunabo, PR (787) 861-1012 Hours: Monday – Friday 9:00am to 3:00 pm USEPA-Caribbean Environmental Protection Division City View Plaza II – Suite 7000 48 RD. 165 Km. 1.2 Guaynabo, P.R. 00968-8069 (787) 977-5865 Hours: Mon - Fri 9:00 a.m. to 5:00 p.m. By appointment Puerto Rico Environmental Quality Board Emergency Response and Superfund Program Edificio de Agencias Ambientales Cruz A. Matos Urbanización San José Industrial Park 1375 Avenida Ponce de León San Juan, PR 00926-2604 (787)767-8181 ext. 3207 Hours: Monday – Friday 9:00am to 3:00 pm By appointment U.S. EPA Records Center, Region 2 290 Broadway, 18th Floor. New York, New York 10007-1866 (212) 637-4308 Hours: Monday-Friday - 9 am to 5 pm By appointment.

R2-0002622


7

pathways and receptors evaluated are: Commercial Indus-trial Workers at Former Sugar Mill and Puerto Rico Bev-erage; Trespassers at Former Sugar Mill and Puerto Rico Beverage; Residents at Former Sugar Mill, Puerto Rico Beverage, and Maunabo River; Recreational Users at Maunabo River; and Construction Workers at Former Sugar Mill and Puerto Rico Beverage. In addition, the potential future use of groundwater will be as a drinking water source for the community once safe cleanup levels have been achieved. Hence, the baseline risk assessment focused on health effect for both children and adults, in a residential setting, that could result from current and fu-ture direct contact with: (1) contaminated soil (e.g., chil-dren ingesting soil); and (2) contaminated groundwater (e.g., through ingestion and inhalation of volatile com-pounds). It is the lead agency’s current judgment that the Preferred Alternative identified in this Proposed Plan, or one of the other alternatives considered in the Proposed Plan, is necessary to protect human health or welfare or the environment for actual or threatened releases of haz-ardous substances into the environment. Human Health Risk Assessment The chemicals of potential concerns (COPCs) identified for the Site are based on criteria outlined in the Risk As-sessment Guidance for Superfund, primarily through comparison to risk‐based screening levels. Two semi‐volatile organic compounds (benzo(a)pyrene and dibenzo(a,h)anthracene) and eight inorganics (alu-minum, arsenic, chromium, cobalt, iron, manganese, thal-lium, and vanadium) are identified as COPCs in the sur-face and subsurface soil at the Former Sugar Mill area. Seven (aluminum, arsenic, chromium, cobalt, iron, man-ganese, and vanadium) inorganics are identified as COPCs in the surface and subsurface soil at the Puerto Rico Beverage area. Five volatile organic compounds (cis-1,2-dichloroethene, tetrachloroethane, trans-1,2-dichloroethene, trichloro-ethene, and vinyl chloride) and nine inorganics (alumi-num, arsenic, barium, chromium, cobalt, copper, iron, manganese, and vanadium) are identified as COPCs in the groundwater. Two VOCs (bromodichloromethane and dibromo-chloromethane) and six inorganics (arsenic, chromium, cobalt, iron, manganese, and vanadium) are identified as COPCs in sediment from the Maunabo River.

Exposure pathways evaluated for soil include ingestion of and dermal contact with soil, inhalation of particulates from soil by commercial/industrial workers, trespassers, residents, and construction workers. Exposure pathways evaluated for groundwater include ingestion of and der-mal contact with groundwater, inhalation of vapor re-leased during showering and bathing, and inhalation of vapor through vapor intrusion by commercial/industrial workers and residents. Exposure pathways evaluated for surface water and sediment include ingestion of and der-mal contact by recreational users. For the current and future land‐use scenarios, total esti-mated cancer risks are within EPA’s target range (cancer risk of 1×10‐6 to 1×10‐4) for all receptors under the Rea-sonable Maximum Exposure (RME) scenario, except res-idents at both the Former Sugar Mill and Puerto Rico Beverage areas. The risks are driven by the potential ex-posure to groundwater as a potable water supply. How-ever, under the Central Tendency Exposure (CTE) sce-nario, the total cancer risks are within EPA’s target range of 1×10‐6 to 1×10‐4. For the current and future land‐use scenarios, total non-cancer health hazards are within EPA’s target threshold (Hazard Index of 1.0) for all receptors under the RME scenario, except commercial and industrial workers, con-struction workers, and residents at both the Former Sugar Mill and Puerto Rico Beverage areas. The current and future commercial/industrial workers, construction work-ers, and residents have non-cancer Hazard Index (HI) exceeding EPA’s threshold of unity under the RME sce-nario for the kidney, respiratory system, lung, and gastro-intestinal (GI) tract. Non-cancer health hazards for cur-rent and future commercial/industrial workers and con-struction workers are almost entirely due to the hypothet-ical use of contaminated groundwater as a potable water supply. For current and future residents, the potential health hazards to the kidney are results of exposure of cis‐1,2‐DCE and vanadium in groundwater, while the potential adverse health effects to the respiratory system are results of exposure to vanadium in soil and ground-water. The potential adverse health effects to the lung and GI tract are mainly results of exposure to arsenic and iron, respectively, in both soil and groundwater. Under the CTE scenario, the HIs still exceed EPA’s threshold of unity for the same target organs/effects, except lung and GI tract, affected under the RME.

R2-0002623


8

Cancer Risk Scenarios (Current Scenario)

Scenario Area Risk


Former Sugar Mill PR Beverage

4 x 10-5

4 x 10-5

Trespassers Former Sugar Mill PR Beverage

9 x 10-7

1 x 10-6

Residents Former Sugar Mill 2 x 10-4

(RME) 8 x 10-5 (CTE)

Recreational Users Maunabo River 9 x 10-7

Cancer Risk Scenarios

(Future Scenario)

Scenario Area Risk

Residents PR Beverage Maunabo River

2 x 10-4

(RME) 8 x 10-5 (CTE) 2 x 10-5

Future Construction Workers


2 x 10-7

8 x 10-8

Non-Cancer Health Hazard Scenarios

(Current Scenario)

Scenario Area Hazard Index



Total: 5 (RME) Kidney: 5 Respiratory Sys-tem: 4 Total: 4 (CTE) Kidney: 3 Respiratory Sys-tem: 3 Total: 5 (RME) Kidney: 4 Respiratory Sys-tem: 4 Total: 3 (CTE) Kidney: 3 Respiratory Sys-tem: 3

Trespasser Former Sugar Mill PR Beverage

Total: 0.8 Total:0.7

Residents Former Sugar Mill

Total: 36 (RME) Kidney: 32 Respiratory Sys-tem: 30 Lung: 2 GI* Tract: 2 Total: 16 (CTE) Kidney: 14 Respiratory Sys-tem: 13

Recreational Users

Maunabo River Total: 1

* GI = Gastrointestinal

R2-0002624


9

Non-Cancer Health Hazard Scenarios (Future Scenario)

Scenario Area Hazard Index

Residents PR Beverage

Maunabo River

Total: 34 (RME) Kidney: 31 Respiratory Sys-tem: 4 Lung: 2 GI* Tract: 2 Total: 15 (CTE) Kidney: 13 Respiratory Sys-tem: 13 Total: 0.007

Construction Workers

Former Sugar Mill

Total: 2 Kidney: 2 Respiratory System: 2

PR Beverage Total: 2 Kidney: 2 Respiratory System: 2

* GI = Gastrointestinal The vapor intrusion pathway was also evaluated. This exposure pathway was evaluated by performing a screen-ing evaluation in order to determine if this exposure pathway is complete. Several contaminant concentra-tions exceeded their respective criteria. However, further evaluation identified that these exceedances were either located more than 100 feet away from any nearby resi-dences or at a depth where an uncontaminated groundwa-ter layer is above the contaminated groundwater. Con-sidering the multiple lines of evidence, it was determined that vapor intrusion is currently not a concern. Screening Level Ecological Risk Assessment A screening-level ecological risk assessment (SLERA) was conducted to evaluate the potential for ecological risks from the presence contaminants in surface soil, sed-iment, pore water and surface water. The SLERA focused on evaluating the potential for impacts to sensitive eco-logical receptors to site-related constituents of concern through exposure to soil, sediment, pore water and sur-face water. Concentrations of compounds detected in surface soil, sediment, pore water and surface water were compared to ecological screening values as an indicator of the potential for adverse effects to ecological recep-

tors. A complete summary of all exposure scenarios can be found in the SLERA Report, which is part of the Ad-ministrative Record for this Site. Based on a comparison of maximum detected concentra-tions of contaminants in site soil, sediment, pore water and surface water, to conservatively derived Ecological Screening Levels (ESLs), the potential for ecological risk may occur. The chemicals of potential concern (COPCs) identified by media at the Site are:

Soil: cadmium, chromium, copper, lead, manga-nese, mercury, vanadium, and zinc

Sediment: copper Porewater: aluminum, barium, and iron Surface water: barium

The following media‐specific contaminants (VOCs and metals) were all retained as COPCs due to a lack of me-dia‐specific ESLs.

Soil: carbazole Sediment: barium and vanadium Surface water: bromodichloromethane and

dibromochloromethane Based on a comparison of maximum detected concentra-tions of contaminants in site soil, sediment, surface water, and porewater to conservatively derived Ecological Screening Levels (ESLs), the potential for ecological risk may occur. The chemicals of potential concern (COPCs) identified by media at the Site are:

Soil: cadmium, chromium, copper, lead, manga-nese, mercury, vanadium, and zinc

Sediment: copper Surface water: barium Porewater: aluminum, barium, and iron

The following media‐specific contaminants (VOCs and metals) were all retained as COPCs due to a lack of me-dia‐specific ESLs:

Soil: carbazole Sediment: barium and vanadium Surface water: bromodichloromethane and

dibromochloromethane COPCs retained via comparison to their respective me-dia‐specific ESLs were all comprised of metals and sev-eral non-site related VOCs and a pesticide were retained due to a lack of a screening value. However, there were no site‐related chemicals (e.g., PCE and DCE) detected in any media evaluated in the SLERA. The compounds de-tected above conservative ESLs or those that were re-

R2-0002625


10

tained due to a lack of a screening value are most likely reflective of natural conditions, or non site‐related sources. Therefore, the Site poses no site‐related risk to ecological communities present. It is EPA’s current judgment that the Preferred Alterna-tive identified in this Proposed Plan, or one of the other active measures considered, is necessary to protect public health, welfare and the environment from actual or threatened releases of hazardous substances into the envi-ronment. REMEDIAL ACTION OBJECTIVES Remedial action objectives (RAOs) are specific goals to protect human health and the environment. These objec-tives are based on available information and standards, such as applicable or relevant and appropriate require-ments (ARARs), to-be-considered guidance, and site-specific risk-based levels. The RAOs for the Site are:

Protect human health by preventing exposure via ingestion, inhalation, or dermal contact to con-taminated groundwater with concentrations above Preliminary Remediation Goals (PRGs); and

Remediate the groundwater to the extent practi-cable by reducing Site contaminant concentra-tions to PRGs.

The PRGs selected for this Site are:

Contaminant PRG*

PCE 5 µg/L cis 1,2-DCE 70 µg/L 1,1-DCE 25 µg/L *National Primary Drinking Water Standards Contaminated groundwater is the media of interest for the Site. Surface and subsurface soil samples collected during the RI did not identify a source of site‐related VOCs. Site related contaminants are chlorinated volatile organic compounds, including PCE, TCE, cis‐1,2‐DCE, 1,1‐DCE. These contaminants may pose risks to human health through inhalation, ingestion, and dermal contact. Based on the groundwater data collected during the RI, there are three separate plumes at the Site (Figure 3). These three plumes are located in different areas of the Site and have characteristic contaminant profiles. The cis‐1,2‐DCE plume is located between the PRB Area and the Maunabo #1 public supply well. The PCE plume is located between

the FSM Area and the Maunabo #1 public supply well. The 1,1‐DCE plume is located northwest of the Maunabo #4 public supply well. The groundwater plumes are with-in a designated Wellhead Protection Area and the public supply wells (Maunabo #1 and Maunabo #4) are current-ly in operation. Summary of Remedial Alternatives Remedial alternatives were assembled by combining the retained remedial technologies and process options for each contaminated media. The remedial alternatives to address groundwater contamination in each of the three plumes are summarized below. The proposed remedial alternative for the Site is Alternative 3: Air Sparging/Soil

Vapor Extrusion (cis-1,2-DCE plume) and Monitored

Natural Attenuation (PCE and 1,1-DCE plumes).

Alternative 1: No Action The No Action alternative is retained for comparison purposes as required by the NCP. No remedial action would be implemented as part of this alternative. It does not include any institutional controls or monitoring pro-gram. Five‐year reviews would be conducted by EPA to assess Site conditions. No cost is included in the Feasibil-ity Study for five-year reviews since they would be per-formed by EPA. Per CERCLA, alternatives resulting in contaminants re-maining above levels that allow for unrestricted use and unlimited exposure require that the Site be reviewed at least once every five years. If justified by the review, ad-ditional remedial actions may be implemented to remove, treat, or contain the contamination. The review would include a site‐wide visual inspection and a report pre-pared by EPA. Alternative 2: Monitored Natural Attenuation Alternative 2 - Monitored Natural Attenuation (MNA) relies upon naturally occurring destructive mechanisms (biodegradation, dilution, and dispersion) to address the PCE, cis‐1,2‐DCE and 1,1‐DCE plumes. Routine moni-toring and contaminant concentration trend analysis are generally performed as part of the MNA response action to demonstrate that contaminants do not represent signifi-cant risk and that degradation of the contaminants is oc-curring. If monitoring indicates that levels are not de-creasing sufficiently, a contingency plan would need to be implemented. If asymptotic contaminant concentration

R2-0002626


11

levels are achieved, an active remedy (e.g., targeted injec-tion, etc.) may be necessary to achieve PRGs. Alternative 2 consists of the following major activities:

Pre‐design investigation/MNA study Institutional controls Long‐term monitoring Five‐year review

To help address the uncertainty surrounding contaminant concentration reduction via MNA, an MNA investiga-tion/study would be required in order to provide infor-mation to better project the effectiveness of natural atten-uation mechanisms at field scale and to confirm that ac-tive degradation of contaminants is occurring where needed. Institutional controls should restrict the future use of the Site and groundwater, and should require precautions to be taken to protect human health in the event remedial measures are disturbed. Long-term monitoring of Site groundwater can be im-plemented when contaminants remain above levels that allow for unrestricted use and unlimited exposure. The monitoring program should continue until concentrations have stabilized or meet remedial goals. According to CERCLA, alternatives resulting in contam-inants remaining above levels that allow for unrestricted use and unlimited exposure require that the Site be re-viewed at least once every five years. If justified by the review, additional remedial actions may be implemented to remove, treat, or contain the contamination. The re-view would include a site‐wide visual inspection and a report prepared by EPA. Alternative 3: Air Sparging/Soil Vapor Extrusion (cis 2,2-DCE)) and Monitored Natural Attenuation (PCE and 1,1-DCE Plumes) Under Alternative 3, Monitored Natural Attenuation (MNA) would be implemented for the PCE and 1,1‐DCE plumes as presented in Alternative 2. In addition, under this alternative, Air Sparging (AS) would be used to re-move VOCs from the groundwater in the cis‐1,2‐DCE plume and reduce concentrations to below the PRGs. Air sparging is a technology in which air is injected into the subsurface through sparge points. The injected air acts to remove or “strip” the VOCs from the groundwa-ter. A grid of sparge points would be installed in areas of

slow moving groundwater—relatively far from the pump-ing well (Maunabo #1),, and a row of sparge points (a sparge curtain) would be installed closer to the well in the faster moving groundwater. Each sparge point is assumed to have a 10‐foot radius of influence. This configuration is considered to be cost‐ and performance‐optimized compared to a configuration consisting solely of a grid of sparge points across the entire plume. A Solid Vapor Extraction (SVE) system will be imple-mented to collect the VOCs stripped from groundwater by the sparge system. It should be noted that since con-centrations in groundwater are low, the mass collected by the SVE system would be very low and potentially below detection limits in the SVE system effluent. Furthermore, biodegradation from the aerobic conditions created by the AS system would further decrease the mass of cis‐1,2‐DCE and VC to be captured by the SVE. An air sparging pilot test would be required to determine the radius of influence of each sparge location and soil vapor extraction well, and consequently the number of sparge points needed. The pilot test would also evaluate the need for treatment of the collected vapors. Data obtained during the RI, pre‐design investiga-tion/MNA study, and air sparging pilot test would be used to develop the detailed approach for Site remedia-tion during Remedial Design. All aspects necessary for implementing the remedial action would be considered, including but not limited to: detailed layout of the treat-ment strategy and system, construction sequence, regula-tory requirements, and cost estimates. It is anticipated that the sparge grid would be operated for one year and the sparge curtain for three years. Perfor-mance monitoring would be conducted at groundwater monitoring wells installed in the sparge grid as well as upgradient and downgradient of the sparge curtain. Pre-design investigation/MNA study, institutional con-trols, long-term monitoring, and five-year review activi-ties are similar to the described ones in Alternative 2. Alternative 4: In‐situ Bioremediation (cis‐1,2‐DCE plume) and Monitored Natural At-

tenuation (PCE and 1,1‐DCE plumes) Under this alternative, in‐situ bioremediation could be implemented within the 70 μg/L contour in the cis‐1,2‐DCE plume, with institutional controls for protec-tion of human health. In the PCE and 1,1‐DCE plumes,

R2-0002627


12

MNA would be relied upon to ensure that the groundwa-ter remediation RAO is met, as described in Alternative 2. As part of the bioremediation alternative, a microcosm study would be conducted to better understand the natural biological activity within the plume and the effects of amendments on the microbes’ ability to reduce contami-nant concentrations. The microcosm study would evalu-ate the effectiveness of an amendment called EHC® and others such as lactate/whey in order to select the most cost‐effective amendment(s) for this Site. A pilot study may need to be conducted prior to the remedial design to obtain site‐specific design parameters for the full-scale implementation of bioremediation. A pre‐design investi-gation would be conducted to further delineate the verti-cal and lateral extent of the treatment zone in the plume. In‐situ bioremediation of the cis‐1,2‐DCE plume would be conducted by injecting the selected amendment(s) in the form of bio‐barriers, a series of injection points, over the target treatment area, delineated during the pre-design investigation. The amendment can be injected using di-rect push technology or permanent injection points. Based upon the low concentrations of the contaminants, only one round of amendment injection may be neces-sary. The reducing conditions created by the amendment injection would potentially enhance natural attenuation of remaining low concentration contaminants in the vicinity of treatment. In the PCE and 1,1‐DCE plumes, MNA would be relied upon to ensure that the groundwater remediation RAO is met, as described in Alternative 2. Institutional controls such as deed restrictions and well drilling restrictions would be implemented to eliminate the exposure path-ways of contaminated groundwater to receptors. Long‐term monitoring would involve annual groundwater sampling and periodic reviews to monitor and evaluate contaminant migration and concentration changes in the aquifer. Alternative 4 includes the following components:

Pre‐design investigation Microcosm and pilot study Remedial Design In‐situ bioremediation of cis‐1,2‐DCE plume Institutional controls Long‐term monitoring Five‐year reviews

According to CERCLA, alternatives resulting in contam-inants remaining above levels that allow for unrestricted

use and unlimited exposure require that the Site be re-viewed at least once every five years. If justified by the review, additional remedial actions may be implemented to remove, treat, or contain the contamination. The re-view would include a site‐wide visual inspection and a report prepared by EPA. Evaluation of Remedial Alternatives Nine Superfund evaluation criteria are used to evaluate the different remedial alternatives individually and against each other in order to select the best alternative.

THE NINE SUPERFUND EVALUATION CRITERIA 1. Overall Protectiveness of Human Health and the Envi-ronment evaluates whether and how an alternative elimi-nates, reduces, or controls threats to public health and the environment through institutional controls, engineering con-trols, or treatment. 2. Compliance with Applicable or Relevant and Appropri-ate Requirements (ARARs) evaluates whether the alterna-tive meets federal and state environmental statutes, regula-tions, and other requirements that pertain to the site, or whether a waiver is justified. 3. Long-term Effectiveness and Permanence considers the ability of an alternative to maintain protection of human health and the environment over time. 4. Reduction of Toxicity, Mobility, or Volume (TMV) of Contaminants through Treatment evaluates an alterna-tive's use of treatment to reduce the harmful effects of princi-pal contaminants, their ability to move in the environment, and the amount of contamination present. 5. Short-term Effectiveness considers the length of time needed to implement an alternative and the risks the alterna-tive poses to workers, the community, and the environment during implementation. 6. Implementability considers the technical and administra-tive feasibility of implementing the alternative, including fac-tors such as the relative availability of goods and services. 7. Cost includes estimated capital and annual operations and maintenance costs, as well as present worth cost. Present worth cost is the total cost of an alternative over time in terms of today's dollar value. Cost estimates are expected to be accurate within a range of +50 to -30 percent. 8. State/Support Agency Acceptance considers whether the State agrees with the EPA's analyses and recommenda-tions, as described in the RI/FS and Proposed Plan. 9. Community Acceptance considers whether the local community agrees with EPA's analyses and preferred alter-native. Comments received on the Proposed Plan are an important indicator of community acceptance.

R2-0002628


13

Each alternative has been evaluated against these nine criteria and compared to the other alternatives under con-sideration. The evaluation of the alternatives in relation to the nine criteria is discussed below. A more detailed analysis of the presented alternatives can be found in the Feasibility Study report.

1. Overall Protection of Human Health and the Environment

Alternative 1 would not meet the RAOs and would not be protective of human health and the environment since no action would be taken. Contamination would remain in the groundwater, while no mechanisms would be imple-mented to prevent exposure to contaminated groundwa-ter, or to reduce the toxicity, mobility, or volume of con-tamination except through natural attenuation processes, which would not be monitored to assess the effectiveness or predict the duration of this alternative. Alternative 2 would meet the RAOs. It is important to note that although historical data in Maunabo #1 has not shown contaminants above the MCLs since 2006, the cis‐1,2‐DCE plume is within the capture zone of Maunabo #1. If natural attenuation does not occur within a reasonable time frame, there is the potential that the concentrations above the PRGs that are currently present in the plume would enter the Maunabo #1 supply well in the future, potentially impacting human health. Addition-al data collection would be needed to confirm that con-centrations are decreasing through natural attenuation and the PRGs would be met within a reasonable timeframe. Similarly, for the PCE and 1,1‐DCE plume, it is uncertain if natural attenuation is occurring at a great enough rate to permanently reduce concentrations to below the PRGS within a reasonable timeframe. Alternatives 3 and 4 will meet the RAOs. The AS/SVE system for Alternative 3 and the bio‐barriers in Alterna-tive 4 would each serve to reduce the concentration of contaminants in groundwater being drawn into the Maunabo #1 supply well, providing protection of human health. Only bio-amendments that are safe to be injected into the aquifer near a public supply well will be consid-ered and further evaluated during the microcosm study. Alternatives 2, 3, and 4 would provide adequate control of risk to human health by implementing institutional and engineering controls. 2. Compliance with Applicable or Relevant and

Appropriate Requirements (ARRAs)

Alternative 1 would not achieve chemical‐specific ARARs established for groundwater. Location and ac-tion‐specific ARARs do not apply to this alternative since no remedial action would be conducted. For Alternative 2, further data collection would be need-ed to confirm the ability of natural attenuation to reduce concentrations and comply with ARARs. If natural atten-uation does not occur within a reasonable time frame, ARARs would not be met. This is true also of the PCE and 1,1‐DCE plumes for Alternatives 3 and 4. For the cis‐1,2‐DCE plume, these two alternatives would meet the chemical-specific ARARs over the long‐term because implementation of AS/SVE or in‐situ treatment processes would significantly reduce contaminant concentrations in the treatment area. There are no location-specific ARARs for this Site. Alternatives 2 through 4 would comply with action‐specific ARARs 3. Long-Term Effectiveness and Permanence Alternative 1 would not be effective or permanent since there would be no mechanisms to prevent exposure to contaminated groundwater. Alternative 2 would provide long‐term effectiveness and permanence by relying on natural attenuation to perma-nently reduce contaminant concentrations in the three plumes. However, for the cis‐1,2‐DCE and 1,1‐DCE plumes, it is uncertain if natural attenuation is occurring at a great enough rate to reduce concentrations to below the PRGs within a reasonable timeframe. Alternatives 3 and 4 differs from Alternative 2 in that these alternatives would provide long‐term effectiveness and permanence in the cis‐1,2‐DCE plumes by using in‐situ treatment to reduce the contaminant mass in the treatment area. Alternatives 3 and 4 would provide the greatest permanent mass reduction of contamination within the cis‐1,2‐DCE plume within the shortest period of time. Remaining low contaminant concentrations in all three plumes would be reduced through natural attenua-tion processes. Institutional controls in Alternatives 2, 3 and 4 would prevent exposure to contaminated groundwater while groundwater quality is restored via natural attenuation processes. The long‐term effectiveness of the selected alternative would be assessed through routine groundwa-ter monitoring and reviews every five years (five-year review process).

R2-0002629


14

4. Reduction of Toxicity, Mobility, or Volume

Through Treatment Alternative 1 would not reduce the contaminant toxicity, mobility, or volume (T/M/V) since no remedial action would be conducted. For Alternative 2, the total volume of contaminated groundwater in all three plumes might increase if natural attenuation processes are unable to contain the plume. The extent and effectiveness of toxicity reduction path-ways via natural attenuation, especially ongoing biodeg-radation of chlorinated contaminants, would need to be verified with further data collection. Alternatives 3 and 4 would be the most effective in re-ducing toxicity and volume of contamination through treatment in the cis‐1,2‐DCE plume. Furthermore, the sparge curtain (Alternative 3) and bio‐barriers (Alterna-tive 4) would serve to limit the mobility of the cis‐1,2‐DCE plume beyond its existing footprint. In the 1,1‐DCE plume, mobility would not be reduced via Al-ternative 3 or 4. However, toxicity and volume will po-tentially be reduced by biodegradation. T/M/V would not be reduced in the PCE plume since the mechanisms of natural attenuation would be dilution and dispersion, and not biodegradation. 5. Short-Term Effectiveness With respect to Alternative 1, there would be no short‐term impact to the community and environment as no remedial action would occur. For long‐term monitor-ing to be conducted on private property, coordination and access would need to be obtained from private property owners. There would be short‐term impacts to the local communi-ty and workers for Alternatives 3 and 4 in the cis‐1,2‐DCE plume due to the active remedial actions undertaken and associated construction, operation, and/or injection activities. Implementing MNA in the PCE plume and 1,1‐DCE plume would not be effective in the short term, since effectiveness would rely upon the dilu-tion and dispersion created by groundwater flow and nat-urally occurring biodegradation to reduce concentrations to PRGs. Air monitoring, engineering controls, and ap-propriate worker Personnel Protective Equipment would be used to protect the community and workers for Alter-natives 2 through 4.

6. Implementability Alternative 1 would be easiest both technically and ad-ministratively to implement as no additional work would be performed at the Site. Alternatives 2 through 4 would be technically imple-mentable since services, materials, and experienced ven-dors would be readily available. Bench and pilot studies would be implemented to obtain Site‐specific design pa-rameters. Access agreements would be required to im-plement the selected alternative on private properties. Permit requirements would have to be met to inject bio-remediation amendment into the subsurface and/or to dis-charge vapor from an air sparge system to the atmosphere (if required). Overall, Alternative 4 would be the most difficult to implement, followed by Alternative 3, then Alternative 2. 7. Cost There are no costs associated with Alternative 1. The total present worth for Alternative 2 is $2.4 million. The total present worth for Alternative 3 is $4.6 million. The total present worth for Alternative 4 is $4.5 million. 8. State/Support Agency Acceptance The Commonwealth of Puerto Rico agrees with the pre-ferred alternative in this Proposed Plan. 9. Community Acceptance Community acceptance of the preferred alternative will be evaluated after the public comment period ends and will be described in the Responsiveness Summary section of the Record of Decision for this site. The Record of Decision is the document that formalizes the selection of the remedy for a site. SUMMARY OF THE PREFERRED ALTERNATIVE Alternative 3: Air Sparging/Soil Vapor Extrusion (cis-

1,2-DCE plume) and Monitored Natural Attenuation

(PCE and 1,1-DCE plumes).

Alternative 3 consists of the following major activities: Pre‐design investigation/MNA study AS pilot study Remedial design AS/SVE installation/operation Institutional controls

R2-0002630


15

Long‐term monitoring Five-year reviews

Overall Protection of Human Health and the En-vironment This alternative would provide protection of human health and the environment. AS/SVE would remove the contaminants within the cis‐1,2‐DCE plume permanently; the remaining very low contaminant concentrations are expected to be reduced through natural processes such as dilution, dispersion, and biodegradation. During remediation, exposure to groundwater in all three plumes—beyond the exposure route of the existing sup-ply wells—would be prevented through institutional con-trols. This alternative would meet the RAOs. Institutional controls would eliminate the exposure pathway for con-taminated groundwater to local receptors before the RAOs and the PRGs are achieved. Compliance with ARARs Alternative 3 would not meet chemical‐specific ARARs in the short term in the PCE and 1,1‐DCE plumes because COC concentrations would continue to exceed the PRGs in groundwater while natural attenuation is taking place. However, over time in all three plumes, the existing con-centrations of COCs may decrease to acceptable levels within a reasonable timeframe by either AS/SVE or natu-ral attenuation. If natural attenuation is not proceeding effectively, a contingency remedy would need to be im-plemented to meet chemical‐specific ARARs. This alter-native would follow health and safety requirements to meet the action‐specific ARARs. There are no loca-tion‐specific ARARs for this Site. Long-term Effectiveness and Permanence AS/SVE would permanently remove contamination by stripping contaminants from groundwater. It is important to note that the proposed configuration of sparge points assumes that Maunabo #1 would continue operating as it currently operates. The sparge curtain layout is proposed in order to harness the hydraulic gradient created by the pumping to draw water into the sparge curtain treatment zone. If the well ceases pumping, the curtain would still be effective, but treatment would take a longer time since the groundwater flow velocity through the curtain would decrease.

An additional factor to consider is aerobic biodegrada-tion. Since volatile compounds and cis‐1,2‐DCE are known to be degradable by aerobic bacteria, the introduc-tion of oxygen into the aquifer by the sparge system should stimulate the growth of aerobic bacteria capable of degrading these two compounds. Contaminants remain-ing outside the treatment zone are at low concentrations, and would be reduced over time through dilution and dis-persion. Overall, this alternative provides an effective, permanent remedy for the cis‐1,2‐DCE plume. Natural processes such as dilution, dispersion, and biodegradation would reduce concentrations permanently in the PCE and 1,1‐DCE plumes. Institutional controls would prevent exposure to contaminated groundwater before the groundwater quality would be restored to PRGs in each of the three plumes. The long‐term monitoring program and five‐year reviews would assess the contamination conditions. Reduction of Toxicity, Mobility, or Volume (T/M/V) Through Treatment This alternative would significantly reduce the T/M/V of contamination in the cis‐1,2‐DCE plume. The volume and toxicity of contaminated groundwater would be reduced by the stripping of contamination from groundwater. The mobility of soil vapor would be controlled by the vacuum applied to the treatment area, which would prevent vapor migration. In the 1,1‐DCE plume, mobility would not be reduced. However, toxicity and volume will potentially be reduced by biodegradation. T/M/V would not be re-duced in the PCE plume since the mechanisms of natural attenuation would be dilution and dispersion, and not bi-odegradation. Short-term Effectiveness This alternative would have some short-term impacts to the community and the environment. AS/SVE would need to be installed and operated on the Site for approxi-mately three years. Installation of the system would be performed without significant risk to the community. Site workers would wear appropriate personal protection equipment (PPE) to minimize exposure to contamination and as protection from physical hazards. AS/SVE will be effective in the short-term. VC and cis-1,2-DCE are vola-tile compounds that can be stripped relatively effectively from groundwater with sparging. The aerobic conditions in the groundwater created by the sparge system will in-duce a degree of biodegradation of the contaminants. Im-plementing MNA in the PCE plume and 1,1-DCE plume would not be effective in the short-term, since effective-

R2-0002631


16

ness would rely upon the dilution and dispersion created by groundwater flow and naturally occurring biodegrada-tion to reduce concentrations to the PRG. Implementability MNA and AS/SVE are well established technologies and could be readily implemented at the Site. This alternative would require the use of readily available conventional construction and subsurface drilling equipment. Ground-water monitoring associated with MNA would be easily implemented using readily available services and materi-als. Costs The total present worth for Alternative 3 is $4.6 million. The estimated capital cost is $1.9 million for the first five years, the estimated O&M is $0.6 million, and monitor-ing cost is $2 million for 30 years. State/Support Agency Acceptance The Commonwealth of Puerto Rico agrees with the pre-ferred alternative Community Acceptance Community acceptance of the preferred alternative will be evaluated after the public comment period ends. COMMUNITY PARTICIPATION EPA provided information regarding the cleanup of the Maunabo Groundwater Contamination Site to the public through public meetings, the Administrative Record file for the site and announcements published in the La Esquina and Primera Hora newspapers. EPA encourages the public to gain a more comprehensive understanding of the Site and the Superfund activities that have been conducted there. For further information including EPA’s preferred alter-native for the Maunabo Groundwater Contamination Site, contact:

Luis E Santos Remedial Project Manager

(787) 977-5865

Brenda Reyes Community Relations

(787) 977-5869

EPA-Caribbean Environmental Protection Division

City View Plaza II – Suite 7000 48 RD. 165 Km. 1.2

Guaynabo, P.R. 00968-8069 (787) 977-5865

Or access EPA web page at: http://www.epa.gov/region02/superfund/npl/maunabo

The dates for the public comment period; the date, the location and time of the public meeting; and the locations of the Administrative Record files are provided on the front page of this Proposed Plan. GLOSSARY ARARs: Applicable or Relevant and Appropriate Require-ments. These are Federal or State environmental rules and regulations that may pertain to the site or a particular alterna-tive. Carcinogenic Risk: Cancer risks are expressed as a number reflecting the increased chance that a person will develop can-cer if exposed to chemicals or substances. For example, EPA’s acceptable risk range for Superfund hazardous waste sites is 1 × 10-4 to 1 × 10-6, meaning there is 1 additional chance in 10,000 (1 × 10-4) to 1 additional chance in 1 million (1 × 10-6) that a person will develop cancer if exposed to a Site contami-nant that is not remediated. CERCLA: Comprehensive Environmental Response, Com-pensation and Liability Act. A Federal law, commonly referred to as the “Superfund” Program, passed in 1980 that provides for response actions at sites found to be contaminated with haz-ardous substances, pollutants or contaminants that endanger public health and safety or the environment. COPC: Chemical of Potential Concern. SLERA: Screening Level Ecological Risk Assessment. An evaluation of the potential risk posed to the environment if re-medial activities are not performed at the site. FS: Feasibility Study. Analysis of the practicability of multiple remedial action options for the site. Groundwater: Subsurface water that occurs in soils and geo-logic formations that are fully saturated. HHRA: Human Health Risk Assessment. An evaluation of the risk posed to human health should remedial activities not be implemented. HI: Hazard Index. A number indicative of non-carcinogenic health effects that is the ratio of the existing level of exposure to an acceptable level of exposure. A value equal to or less than one indicates that the human population is not likely to experi-ence adverse effects. HQ: Hazard Quotient. HQs are used to evaluate non-carcinogenic health effects and ecological risks. A value equal to or less than one indicates that the human or ecological popu-lation is not likely to experience adverse effects.

R2-0002632

http://www.epa.gov/region02/superfund/npl/maunabo



17

ICs: Institutional Controls. Administrative methods to prevent human exposure to contaminants, such as by restricting the use of groundwater for drinking water purposes. IEUBK: The Integrated Exposure Uptake Biokinetic Model is a mathematical model that predicts the blood lead concentra-tion in humans due to exposure to lead in air, food, water, dust, and soil. The model can also be used to develop cleanup goals for lead that are protective of public health. Nine Evaluation Criteria: See text box on Page 7. Non-carcinogenic Risk: Non-cancer Hazards (or risk) are ex-pressed as a quotient that compares the existing level of expo-sure to the acceptable level of exposure. There is a level of ex-posure (the reference dose) below which it is unlikely for even a sensitive population to experience adverse health effects. EPA’s threshold level for non-carcinogenic risk at Superfund sites is 1.0, meaning that if the exposure exceeds the threshold; there may be a concern for potential non-cancer effects. NPL: National Priorities List. A list developed by EPA of un-controlled hazardous substance release sites in the United States that are considered priorities for long-term remedial evaluation and response. Operable Unit (OU): a discrete action that comprises an incremental step toward comprehensively addressing site problems. This discrete portion of a remedial response manages migration, or eliminates or mitigates a release, threat of a release, or pathway of exposure. The cleanup of a site can be divided into a number of operable units, depending on the complexity of the problems associated with the site. Practical Quantitation Level (PQL): means the lowest concentration of a constituent that can be reliably achieved among laboratories within specified limits of precision and accuracy during routine laboratory operat-ing conditions. Present-Worth Cost: Total cost, in current dollars, of the re-medial action. The present-worth cost includes capital costs required to implement the remedial action, as well as the cost of long-term operation, maintenance, and monitoring. PRG: Preliminary Remediation Goal. PRPs: Potentially Responsible Parties. Proposed Plan: A document that presents the preferred reme-dial alternative and requests public input regarding the pro-posed cleanup alternative. Public Comment Period: The time allowed for the members of a potentially affected community to express views and con-cerns regarding EPA’s preferred remedial alternative. RAOs: Remedial Action Objectives. Objectives of remedial actions that are developed based on contaminated media, con-taminants of concern, potential receptors and exposure scenari-os, human health and ecological risk assessment, and attain-ment of regulatory cleanup levels. Record of Decision (ROD): A legal document that describes the cleanup action or remedy selected for a site, the basis for choosing that remedy, and public comments on the selected remedy. Remedial Action: A cleanup to address hazardous substances

at a site. RI: Remedial Investigation. A study of a facility that supports the selection of a remedy where hazardous substances have been disposed or released. The RI identifies the nature and ex-tent of contamination at the facility and analyzes risk associat-ed with COPCs. Saturated Soils: Soils that are found below the Water Table. These soils stay wet. TBCs: “To-be-considereds,” consists of non-promulgated ad-visories and/or guidance that were developed by EPA, other federal agencies, or states that may be useful in developing CERCLA remedies. Unsaturated Soils: Soils that are found above the Water Table. Rain or surface water passes through these soils. These soils remain dry: EPA: United States Environmental Protection Agency. The Federal agency responsible for administration and enforcement of CERCLA (and other environmental statutes and regula-tions), and final approval authority for the selected ROD. VOC: Volatile Organic Compound. Type of chemical that readily vaporizes, often producing a distinguishable odor. Water Table: The water table is an imaginary line mark-ing the top of the water-saturated area within a rock col-umn.

R2-0002633


Figure 1

Site Map

R2-0002634

EPA Region 2 – August 2012 R2-0002635


Figure 2

Groundwater Screening Investigation Samples Location

R2-0002636


Figure 2-1 A Groundwater Screening Locations Groundwater Screening Locations

Maunabo Groundwater Contamination Site

.. ~-A~-G-~_ro_u_n_d_w~at_e_r_n_o_t_e_n_c_o_u_nt_e_r_e_d~~~~~~~~~-o:::•u:.~~~-2:n::::::~:::::::~:·:::::•~._.:_:~~~~~~~~~~~~~~~CDM Maunabo, Puerto Rico smith

R2-0002637


Figure 3

Location of Groundwater Contamination Plume

R2-0002638


Legend - - - Esitmated MCL isocontour

Monitoring Well locations •

Maunabo #1 Public Supply Wells ?

Groundwater Screening Locations

Uncertain lsocontour Boundary A !!""=:=!~~--~====~--~''" 0 106 210 <120 640

Figure 2-1 Plume Map - MCL (IJg/L} lsocontours


R2-0002639

EPA Región 2 – Agosto 2012

INTRODUCCIÓN Este Plan Propuesto identifica la Alternativa Preferida para la limpieza de aguas subterráneas contaminadas en el área de Maunabo, Lugar de Superfondo de Contamina-ción de Agua Subterránea, del área de Maunabo Puerto Rico, y proporciona las razones para esta preferencia. Además, este Plan Propuesto incluye resúmenes de otras alternativas de limpieza evaluadas para este Lugar. La Agencia Federal de Protección Ambiental (EPA), agencia principal para las actividades del Lugar y la Junta de Ca-lidad Ambiental (JCA), la agencia de apoyo, emitieron este documento. La EPA, en consulta con la JCA, selec-cionará el remedio final para el Lugar después de revisar y considerar toda la información presentada durante los 30 días del período de comentarios público. La EPA, en consulta con JCA, podrá modificar la alternativa preferi-da o seleccionar otra respuesta de acción presentada en este Plan Propuesto basado en nueva información obteni-da o comentarios del público. Por lo tanto, se recomienda al público revisar y comentar sobre todas las alternativas presentadas en este Plan. La Agencia Federal de Protección Ambiental (EPA) emi-te esta Plan Propuesto como parte de sus requisitos bajo la sección 117 (a), de Respuesta Ambiental Comprensiva, Ley de Compensación y Responsabilidad (CERCLA, comúnmente conocida como el programa de Superfondo) y la Sección 300.430(f)(2) del Plan de Contingencia Na-cional de Contaminación de Petróleo y Sustancias Peli-grosas. Este Plan Propuesto resume la información que se puede encontrar con mayor detalle en los informes de Investiga-ción Remedial y Estudio de Viabilidad (RI/FS por sus siglas en inglés) y demás documentos contenidos en el Registro Administrativo para el Lugar. La EPA y la JCA exortan al público a revisar estos documentos para obte-ner una comprensión más completa del Lugar y las acti-vidades del Superfondo que se hayan llevado a cabo en el Lugar.

DESCRIPCIÓN DEL LUGAR El sistema público de agua Maunabo Urbano consiste de cuatro pozos de agua subterránea: Maunabo #1 hasta Maunabo #4. Este sistema sirve a una población de aproximadamente 14,000 personas y lo maneja la Autori-

MARQUE SU CALENDARIO

PERÍODO DE COMENTARIOS PÚBLICOS:

9 de agosto de 2012 – 7 de septiembre de 2012

EPA aceptará comentarios por escrito sobre el Plan de Propuesta durante este período de comentarios públi-

cos.

Comentarios escritos deben ser dirigidos a:

Luis E. Santos, Gerente de Proyectos

Agencia Federal de Protección Ambiental División de Protección Ambiental del Caribe

City View Plaza II – Oficina 7000 48 RD. 165 Km. 1.2

Guaynabo, P.R. 00968-8069 Teléfono: (787) 977-5824

Fax: (787) 289-7104 Email:[email protected]

REUNIÓN PÚBLICA:

23 de agosto de 2012 a las 7:00 pm

EPA sostendrá una reunión pública para explicar el

Plan Propuesto y todas las alternativas presentadas en el Estudio de Viabilidad. También se aceptarán co-mentarios por escrito y orales en la reunión. La reu-

nión se llevará a cabo en la Casa Alcaldía de Mauna-bo.

Programa Superfondo Agencia Federal de Protección Ambiental Hoja Informativa Región 2 Lugar de Superfondo Contaminación de Agua Subterránea del Área de Maunabo Maunabo, Puerto Rico Agosto 2012

R2-0002640

PLAN PROPUESTO

Lugar de Superfondo Contaminación de Agua Subterránea del Área de Maunabo

2

dad de Acueductos y Alcantarillados de Puerto Rico (AAA). En 1961, la AAA instaló el pozo de suministro público de agua Maunabo #1 y se utilizó hasta 1974 (Adolphson et al. 1977). En 2001, la AAA decidió reactivar el pozo Maunabo #1. En 2002, la AAA llevó a cabo un muestreo de agua sub-terránea resultando con la presencia de compuestos orgá-nicos volátiles clorinados (COV), tetracloroetano (PCE), tricloroetano (TCE), cis-1-2-dicloroetano (cis-1-2-DCE) y 1-dicloroetano (1,1-DCE). La concentración máxima de PCE, TCE y de cis-1,2-DCE detectada fue de 16.4 microgramos por litro (μg/L), 1.6 μg/L, 4.3 μg/L, respec-tivamente. Los niveles federales máximos de contami-nantes (MCL por sus siglas en inglés) para PCE y TCE son de 5 μg/L y para el cis-1,2-DCE es de 70 μg/L. Además, se recolectaron muestras en los pozos de Mau-nabo #2, #3, y #4 para determinar la presencia de COV. Otro COV, 1,1-dicloroetano (1,1-DCE) se detectó inter-mitentemente en años subsiguientes en Maunabo #1 y Maunabo #4 a niveles por debajo del MCL. Estos COV no estuvieron presentes en muestras recolectadas en los pozos de Maunabo #2 y #3 durante el mismo periodo. Las muestras de agua de la pluma muestran que los con-taminantes detectados en Maunabo #1 estaban presentes en las mismas. En marzo de 2002, el Departamento de Salud de Puerto (DSPR) ordenó a la AAA que cerrará el pozo #1 debido a que la concentración del PCE excedía el MCL federal. Sin embargo, en lugar de cerrar el pozo, la AAA optó por dar tratamiento al agua subterránea a la salida del pozo utilizando tanques de filtración de carbón activado. Se tomaron muestras de agua después del tratamiento como parte de la inspección del DSPR en el 2004, incluyendo muestras de agua de la pluma recolectadas del sistema de distribución en la línea de Maunabo #1 que indicaron que el tratamiento de la AAA no fue efectivo y que el agua potable contaminada estaba llegando a los consumidores. En octubre de 2005, EL Equipo de Evaluación del Lugar 2 de la EPA (SAT por sus siglas en inglés) recolectó muestras de aguas de los pozos Maunabo #1, #2, #3 y #4, y en la línea de distribución de agua. Las muestras fue-ron analizadas para parámetros orgánicos de la Lista de Compuestos (TCL por sus siglas in inglés), básicos/ neu-trales/ ácidos, pesticidas/policlorinados bifeniles (PCB) y de la Lista de Búsqueda de Analitos para parámetros in-orgánicos incluyendo mercurio, cianuro a través del Pro-grama de Laboratorios Contratados (CLP por sus siglas en inglés) de la EPA.

Los datos confirmaron la presencia de PCE y de cis-1,2-DCE en Maunabo #1 y en las muestras después del tra-tamiento a lo largo de la línea de distribución a niveles por debajo del MCL. Los resultados también confirma-ron la presencia de 1,1 DCE en Maunabo #4 y del aditivo de gasolina, metil terbutil éter (MTBE), en Maunabo #1 y en las muestras del sistema de distribución. Los niveles detectados no fueron mayores que los MCL, excepto por el bis(2-etilohexilo) ftalato (6.5 μg/L) en Maunabo #3, que marginalmente excedió el MCL de 6 μg/L. PCE; cis-1,2-DCE; 1,1-DCE; y el MTBE no se detectaron en Maunabo #2 y #3. En diciembre del 2005, SAT 2 llevó a cabo una investi-gación limitada para identificar posibles fuentes de con-taminación del agua subterránea en Maunabo. Las insta-laciones que fueron objeto de ésta investigación incluyen el antiguo Vertedero Municipal de Desperdicios Sólidos de Maunabo (Vertedero de Maunabo), la Planta de Tra-tamiento de Aguas Negras de la AAA localizada cerca del Pozo Maunabo #1, Tienda El Negro Auto Body/Parts, la Estación de Gasolina Esso y cinco facilidades indus-triales ligeras operando bajo el auspicio de la Corpora-ción para el Desarrollo Industrial de Puerto Rico (PRID-CO por sus siglas en inglés). Las cinco facilidades indus-triales de PRIDCO son: Centro de Acopio Manufactu-ring; Juan Orozco Limited, Inc.; Puerto Rico Beverage; Facilidades de Almacenaje de FEMA; y Plastic Home Products. Un resumen y resultados de la investigación limitada de SAT 2 se presentan a continuación. Todas las muestras recolectadas en las propiedades que se describen a conti-nuación fueron analizadas para la presencia de COV TCL a través del CLP de la EPA.

Vertedero de Maunabo ‐ SAT 2 recolectó cua-tro muestras de suelo de superficie, incluyendo un duplicado, una muestra del subsuelo, y una mues-tra de agua subterránea en al antiguo Vertedero de Maunabo. Los COV no se detectaron en las muestras del antiguo Vertedero de Maunabo. No se preparó un informe sobre la evaluación preli-minar/inspección del lugar (PA/SI) de parte del SAT 2 para el vertedero.

Planta de Tratamiento de Aguas Negras de la

AAA ‐ SAT recolectó cuatro muestras de suelo de superficie, dos del subsuelo, y uno de agua subterránea en la Planta de Tratamiento de Aguas Negras de la AAA. No se detectaron COV en las muestras. No se preparó un informe de PA/SI del

R2-0002641

PLAN PROPUESTO


3

SAT 2 para esta facilidad.

Tienda El Negro Auto Body/Parts ‐ El SAT 2 llevó acabo un reconocimiento del lugar en la fa-cilidad. La facilidad se encontró en buen mante-nimiento. Se obtuvo una muestra del suelo de superficie en un área abierta adyacente a la facili-dad. No se detectaron COV en la muestra. SAT 2 no tenía información detallada con relación a prácticas históricas de disposición de residuos en esta facilidad. El PA/SI no recomienda ninguna acción remedial (EPA 2006b).

Estación de Gasolina Total ‐ El SAT 2 reco-

lectó dos muestras de agua subterránea en la Ga-solinera Total. Un aditivo a la gasolina, MTBE, se detectó en 14 y 7J μg/L, en las muestras tam-bién se detectó Benceno en 4J μg/L y 20 μg/L, excediendo éste el MCL de 5 μg/L. El SAT 2 no preparó un informe PA/SI para esta facilidad.

Estación de Gasolina Esso ‐ El SAT 2 reco-

lectó tres muestras de agua subterránea, incluyen-do un duplicado, en la Gasolinera Esso. No se de-tectó ningún COV en las muestras. Ningún in-forme fue preparado por SAT 2 para esta facili-dad.

Centro de Acopio Manufacturing ‐ SAT 2 re-

colectó cuatro muestras del suelo de superficie, dos de subsuelo y una de agua subterránea en una área abierta adyacente al edificio de la facilidad del Centro de Acopio Manufacturing (CAM), uti-lizando el método de empuje directo de Geopro-be™. No se detectaron COV en las muestras. Una revisión del historial disponible indica que estas sustancias no se han generado por las activi-dades en las instalaciones del CAM, ni tampoco fueron identificadasotras fuentes de liberación de residuos sospechosos o que tengan el potencial de liberar contaminantes al agua subterránea o de su-perficie en la facilidad del CAM. El informe PA/SI recomendó no llevar a cabo ninguna otra acción remedial en la facilidad CAM (EPA 2006c).

Juan Orozco Limited, Inc. ‐ El SAT 2 reco-

lectó cuatro muestras de suelo de superficie, dos del subsuelo y una de agua subterránea de un área abierta adyacente al edificio de la facilidad usan-do el método de empuje directo de Geoprobe™. Los resultados analíticos indicaron que no hay de-

tecciones para los contaminantes previamente de-tectados en los pozos de agua del suministro público de Maunabo al igual que los parámetros de COV. Una revisión del historial disponible in-dica que estas substancias no fueron generadas por las actividades de Juan Orozco Limited, ni tampoco cualquier otra fuente de liberación de re-siduos sospechosos o que tengan el potencial de liberar contaminantes al agua subterránea o de su-perficie fueron identificadas en la facilidad. El PA/SI recomendó no llevar a cabo ninguna acción correctiva (EPA 2006d).

Puerto Rico Beverage ‐ SAT 2 recolectó cuatro

muestras de suelo de superficie, dos muestras de subsuelo, y una de agua subterránea en áreas abiertas adyacentes a la facilidades del edificio de Puerto Rico Beverages (PRB por sus siglas en inglés) utilizando el método de empuje directo de Geoprobe™. No se detectaron COV en las muestras. Una revisión del historial disponible indica que estas substancias no fueron generadas por las actividades de PRB, ni tampoco cualquier otra fuente de liberación de residuos sospechosos o que tengan el potencial de liberar contaminantes al agua subterránea o de superficie fueron identi-ficadas en la facilidad. El PA/SI recomendó no llevar a cabo ninguna acción correctiva (EPA 2006e).

Facilidades de Almacenaje de FEMA ‐ El

SAT 2 recolectó cinco muestras de suelo de su-perficie, incluyendo un duplicado, y dos de sub-suelo en áreas abiertas adyacentes a la Facilidad de Almacenaje de FEMA utilizando el método de empuje directo de Geoprobe™. No se detectaron COV en las muestras. (EPA 2006f).

Plastic Home Products ‐El SAT 2 recolectó

cuatro muestras del suelo de superficie y dos muestras del subsuelo en áreas abiertas adyacen-tes a la facilidad de Plastic Home Products (PHP) usando el método directo-empuje del Geopro-be™. No se detectaron COV en las muestras. Una revisión de la información de trasfondo dis-ponible indicó que estas substancias no fueron generadas por las actividades de PRB, ni tampoco cualquier otra fuente de liberación de residuos sospechosos o que tengan el potencial de liberar contaminantes al agua subterránea o de superficie fueron identificadas en la facilidad. El PA/SI re-comendó no llevar a cabo ninguna acción correc-

R2-0002642

PLAN PROPUESTO


4

tiva (EPA 2006g). El SAT 2 recolectó siete muestras de trasfondo; cuatro de suelo de superficie, dos de subsuelo y una de agua subterránea. No se detectaron COV en las muestras. Ba-sado en los datos de octubre y diciembre de 2005, el SAT 2 concluyó que había información insuficiente para de-terminar la fuente de contaminación en los pozos de su-ministro público. La EPA completó el Paquete de Documentación del Sis-tema de Clasificación de Peligro (HRS por sus siglas en inglés) en 2006 (EPA 2006a). El Lugar fue añadido a la Lista de Prioridades Nacionales (NPL por sus siglas en inglés) el 27 de septiembre de 2006. La EPA llevó a cabo una Investigación Remedial (RI por sus siglas en inglés) en el Lugar desde agosto de 2010 hasta julio de 2011. Desde el 25 de agosto hasta el 29 de septiembre de 2010, se llevó a cabo una investigación preliminar delagua subterránea en cinco áreas de fuentes potenciales basado en la información provista en el In-forme de Inspección del Lugar y en el Sistema de Clasifi-cación de Peligros (Weston Solutions 2006) y un recono-cimiento de campo llevado a cabo por la compañía CDM Smith. La investigación preliminar delagua subterránea se llevó a cabo para proporcionar datos sobre la distribu-ción de COV en el agua subterránea. Los datos de detec-ción se utilizaron para apoyar la selección de las ubica-ciones y profundidades de pozos de monitoreo permanen-tes y para identificar las áreas de fuente potencial para el muestreo de suelo subsiguiente. Las muestras prelimina-res de detección en el agua subterránea se recopilaron a lo largo de cuatro Transectos:

Transecto 1 – Este ‐Área de Fuente potencial en la Pendiente Ascendente de Maunabo # 4

Transecto 1‐ Oeste ‐ Área de Fuente Potencial

PRIDCO (incluyendo Puerto Rico Beverage [PRB])

Transecto 2 ‐Área de Fuente Potencial Central

Transecto 3 ‐Área de Fuente Potencial del Nor-

te

Transecto 4 ‐ Área de Fuente Potencial Antigua Central Azucarera

Las muestras de agua subterránea se recolectaron a lo largo de cuatro transectos orientados aproximadamente

perpendiculares a la dirección estimada del flujo del agua subterránea. Las muestras de agua subterránea se recopi-laron utilizando un sistema de muestreo con una malla metálica de 4-pies de largo adjunta a una pieza de tecno-logía de empuje directo. En cada ubicación, las muestras se tomaron a intervalos de 10 pies del fondo del barreno y extiendose al nivel freático. Todas las muestras fueron analizadas para la detección de COV con resultados en un periodo de 24 horas. A continuación se provee un resumen de la investigación preliminar del agua subterránea en las cinco áreas de fuente potencial:

Transecto 1 – Este ‐ Área de Fuente Poten-cial del Sureste ‐ Un total de 37 muestras de agua subterránea, incluyendo duplicados, se reco-lectaron de cuatro localizaciones en pendientes descendentes de un área residencial/comercial y de pendiente ascendente de Maunabo #4.

Transecto 1 – Oeste ‐ Área de Fuente Poten-cial PRIDCO ‐ Un total de 71 muestras de agua subterránea, incluyendo duplicados, se reco-lectaron de 10 localizaciones en un área de pen-diente descendente del Centro de Acopio Juan Orozco Ltd., PRB y de la Planta de Tratamiento de Aguas Negras de la Autoridad de Acueductos y Alcantarillados de Puerto Rico (AAA).

Transepto 2 ‐ Área de Fuente Potencial Cen-

tral ‐ Un total de 10 muestras del agua sub-terránea, incluyendo duplicados se recolectaron de cuatro localizaciones de pendiente descenden-te de la Estación de Gasolina Esso y de Maunabo Dry Cleaners.

Transepto 3 ‐ Área de Fuente Potencial del

Norte ‐ Un total de 12 muestras delagua sub-terránea, incluyendo duplicados, se recolectaron de cuatro localizaciones de pendiente descenden-te de la Facilidad de Acopio de la Agencia Fede-ral para el Manejo de Emergencias (FEMA por sus siglas en inglés), de Plastic Home Products y de la Estación de Gasolina Total.

Transepto 4 ‐ Área de Fuente Potencial de la

Antigua Central Azucarera ‐ Un total de 31 muestras del agua subterránea, incluyendo dupli-cados, se recolectaron de cuatro localizaciones de

R2-0002643

PLAN PROPUESTO


5

pendientes descendentes de las facilidades de FSM, al sur del Río Maunabo.

Desde el 10 al 22 de diciembre de 2010, 64 muestras adi-cionales del agua subterránea, incluyendo los duplicados, se recolectaron y analizaron para encontrar COV. Estas muestras se recolectaron en nueve localizaciones adicio-nales para suplementar el muestreo preliminar. Estas lo-calizaciones adicionales se añadieron para proveer datos para refinar el enfoque sobre las ubicaciones y profundi-dades de los pozos de monitoreos permanentes, incluyen-do pozos de monitoreo de trasfondo. Tres pozos de monitoreo del agua subterránea se utiliza-ron para evaluar la calidad de agua de la pendiente ascen-dente de las áreas impactadas. Las muestras de sedimen-tos y de agua superficiales de trasfondo se recolectaron río arriba de la zona de impacto esperada en el Río Mau-nabo. Se instalaron un total de 16 pozos de monitoreo como parte del RI. Se recolectaron dos rondas de muestras del agua subterránea de los 16 pozos de monitoreo y de cua-tro pozos de suministro público (Maunabo #1 hasta Mau-nabo #4). La primera ronda se llevó a cabo entre el 2 al 8 de marzo de 2011. La segunda ronda se llevó a cabo entre el 7 al 10 de junio, 2011. Durante la investigación de campo de RI, se recolectaron muestras de aguas de superficie de trasfondo en áreas que no se esperaba que fueran impactadas por la contamina-ción relacionada con el Lugar. Estas muestras se analiza-ron para los mismos parámetros analíticos que los mues-treos anteriores. Basándose en los datos recolectados del agua subterránea durante el RI, hay tres plumachos separados en el Lugar (Cis-1,2-DCE, PCE, y 1,1,-DCE) (Figura 2). Estos plu-machos están ubicados en diferentes áreas del Lugar y tienen perfiles característicos de los contaminantes. Las conclusiones para cada una de estos tres plumachos son: Penacho Cis-1,2-DCE ‐ La configuración de este plumacho indica que la decarga de los contaminantes re-lacionados a el Lugar, muy posiblemente PCE o TCE, ocurrió en o cerca de la facilidad PRB. Cis-1,2-DCE, una degradación producto del TCE, se encontró en las con-centraciones más altas (hasta 300 μg/L). COV relaciona-dos incluyendo trans – 1,2 –DCE, 1,1 –DCE y cloruro de vinilo también están presentes, pero normalmente en con-centraciones mucho más bajas. Sólo cis – 1,2 – DCE (hasta 300 μg/L) y el cloruro de vinilo (hasta 1.8 μg/L)

exceden los criterios de detección de agua subterránea. El plumacho está emigrando hacia el suroeste, influen-ciado por el bombeo en el pozo de suministro de Mauna-bo #1 y el flujo de agua subterránea hacia el Río Mauna-bo. El plumacho por lo general está en el linde de la pen-diente ascendente, hacia el sureste y noroeste. Penacho PCE – El principal contaminante de este plu-macho es el PCE, que está presentes en concentraciones que exceden los criterios de detección en un pozo de mo-nitoreo (8.5 J μg/L) y un lugar de detección (7.4 μg/L). El TCE también fue detectado, pero las concentraciones fueron inferiores a los criterios de detección de 5 μg/L. El plumacho esta emigrando hacia el noreste, e influen-ciado por el bombeo del pozo de suministro Maunabo #1 y el flujo del agua subterránea hacia el Río de Maunabo. El borde de la pendiente descendente del plumacho es el pozo de suministro Maunabo #1. Penacho 1,1,-DCE – Este plumacho esta ubicado al noreste del Maunabo #4 y se diferencia del Área FSM y del plumacho del Área de PRB en que consiste mayor-mente de 1,1 – DCE. La concentración más alta fue de-tectada a 25 μg/L. También, 1,1-DCE fue detectado en el pozo de suministro Maunabo #4 (1.1 μg/L). El plumacho aparenta estar emigrando hacia el sureste, hacia el Mau-nabo #4. Sin embargo, el plumacho también puede emi-grar hacia el suroeste, influenciado por el flujo de agua de subterránea hacia el Río Maunabo. Se desconoce la fuen-te del plumacho. Las muestras de suelo y subsuelo se recolectaron en dos áreas de fuentes potenciales, PRB y FSM. Estas áreas se identifican como áreas de fuentes potenciales basado en los resultados de detección del agua subterránea. Las conclusiones para cada una de las dos áreas son: Área PRB– Las muestras de suelo y subsuelo recolecta-das del Área PRB no identificaron una fuente de COV relacionadas con el Lugar. Ninguno de los seis COV re-lacionados con el Lugar se encontraron en las muestras en el área del PRB. Sin embargo, un Compuesto Orgáni-co Volátil Secundario (COVS), bis(2‐etilhexil)ftalato, y varios metales excedieron los criterios de detección. Los COVS y los metales no se consideran relacionados con el Lugar y no afectan el suministro de los pozos públicos. Área FSM– Las muestras de suelo superficial y subsuelo recolectadas en el área del FSM no identificaron una fuente de COV relacionadas con el Lugar. Ninguno de los seis COV relacionados al Lugar fueron encontrados en el área del PRB. Sin embargo, en las muestras de sue-

R2-0002644

PLAN PROPUESTO


6

lo superficial, tres COVS y 12 metales excedieron los criterios de detección y un COVS, benzo (a) pireno, y ocho metales excedieron los criterios de detección en muestras del subsuelo. Los COVS y los metales no se consideran relacionados con el Lugar y no están afectan-do el suministro de los pozos públicos. Las aguas superficiales, los sedimentos y el agua entre –poros o intersticial no han sido impactadas por las des-cargas de contaminantes relacionadas con el Lugar en el agua subterránea. Ninguno de los COV, COVS, pestici-das, PCB ni metales excedieron los criterios de detección en las muestras de agua superficial o el agua entre poros. Seis metales excedieron los criterios de detección en las muestras de sedimento, pero no se consideran relaciona-dos con el Lugar. CARACTERÍSTICAS DEL LUGAR El Lugar está ubicado en el municipio de Maunabo, en la costa sureste de Puerto Rico (18°, 00’, 20.6” latitude nor-te y 65°, 54’, 19 longitud oeste), dentro de un aislado va-lle aluvial (Figura 1). El Lugar está rodeado de montañas al norte, este y oeste y el Mar Caribe al sureste. El punto más alto del área es el Cerro La Pandura a 1,700 pies por encima del nivel del mar (amsl por sus siglas en inglés) y el punto más bajo es el Mar Caribe al sureste. El Río Maunabo y varios riachuelos intermitentes están localiza-dos en las inmediaciones del Lugar y fluyen al sureste hacia el Mar Caribe. La topografía en las cercanías del Lugar se inclina al sur/suroeste, desde las montañas cer-canas, aproximadamente a 180 pies sobre el nivel del mar, hacia el Río Maunabo a 30 pies sobre nivel del mar. La elevación del Lugar es de aproximadamente 40 pies sobre el nivel del mar. Los límites de la Sierra Pandura corren de norte a noreste en la región de Maunabo, en la cual la Pandura, El Sombrerito, en la frontera con Yabu-coa tienen las elevaciones más altas. Con la excepción de las elevaciones arriba mencionadas, el resto del territorio de Maunabo es bastante nivelado. Como resultado de ello, se considera geográficamente parte del Valle Coste-ro del Sur. El Lugar consiste de tres plumachos de agua subterránea (Cis-1,2-DCE, PCE, y 1,1,-DCE) sin ninguna fuente de contaminación identificada (Figura 2). El sistema de agua pública de Maunabo Urbano consiste de cuatro pozos de agua subterránea: Maunabo #1 a Maunabo #4. Se en-contró contaminación en el agua subterránea en dos po-zos de suministros públicos, Maunabo #1 y Maunabo #4. Los cuatro pozos de suministro público fueron completa-dos a profundidades que van de 80 a 125 pies debajo de

la superficie del suelo (bgs por sus siglas en inglés) en el acuífero del valle aluvial de Maunabo. Este acuífero ge-neralmente consiste de arena de gran variedad granu-lométrica, cieno, arcilla, y gravilla de aluvión, incluyendo depósitos lenticulares de arena, gravillas y piedras ovoi-des. La dirección regional del flujo del agua subterránea en la cuenca de Maunabo es al suroeste hacia el Mar Caribe. El “Wellhead Protection Area” está delineado para los pozos de suministro público, de forma tal que los plumachos del agua subterránea queden dentro del “Wellhead Protection Area”. ALCANCE Y DESCRIPCIÓN DE LA ACCIÓN La contaminación de aguas subterráneas se ha definido con suficientes detalles para completar el Informe RI y preparar un estudio de viabilidad y evaluaciones de ries-gos. RESUMEN DE RIESGOS DEL LUGAR Como parte del la Investigación Remedial y el Estudio de Viabilidad (RI/FS por sus siglas en inglés), la EPA llevó a cabo una evaluación de riesgo para determinar los efec-tos actuales y futuros de los contaminantes a la salud humana y al medio ambiente. Los receptores actuales son: Trabajadores de la Industria Comercial de la Anti-gua Central Azucarera y la Puerto Rico Beverage; los residentes en la Antigua Central Azucarera; y los Usura-rios del Área Recreacional del Río Maunabo. Los recep-tores futuros son: Trabajadores de la Industria Comercial de la Antigua Central Azucarera y el Puerto Rico Beve-rage; Intrusos en la Antigua Central Azucarera y Puerto Rico Beverage; Residentes de la Antigua Central Azuca-rera, Puerto Rico Beverage, y el Río Maunabo; Usurarios del área Recreacional del Río Maunabo; y Trabajadores de la Construcción en la Antigua Central Azucarera y la Puerto Rico Beverage. Además, el uso potencial futuro del agua subterránea será como fuente de agua potable para la comunidad una vez que los niveles seguros de limpieza se hayan alcanzado. Por lo tanto, la evaluación de riesgo inicial se enfocó en los efectos a la salud, tanto en niños y adultos, en un área residencial, que pudiera resultar de contacto directo presente y futuro con: (1) sue-lo contaminado (p.ej. niños ingiriendo tierra), y (2) agua subterránea contaminada (p. ej. a través de la ingestión e inhalación de compuestos volátiles). Es el juicio de la actual de la agencia principal que la Alternativa Preferida identificada en este Plan Propuesto, o una de las alterna-tivas consideradas en el Plan Propuesto, sea necesaria

R2-0002645

PLAN PROPUESTO


7

para proteger la salud humana o el bienestar del medio ambiente de presentes o posibles amenazas de descargas de sustancias peligrosas al medio ambiente.

Evaluación del Riesgo a la Salud Humana

Los químicos de potencial preocupación (COPC) por sus siglas en inglés) identificados en el Lugar están basados en los criterios descritos en la Guía de Evaluación de Riesgos para el Superfondo, principalmente a través de la comparación con los niveles de detección basado en los riesgos. Dos componentes orgánicos semi-volátiles (COSV) (ben-zo(a)pireno y dibenzo(a,h)antraceno) y ocho inorgánicos (aluminio, arsénico, cromo, cobalto, hierro, manganeso,

talio y vanadio) se identificaron como COPC en la super-ficie y el subsuelo en el área de la Antigua Central Azu-carera. Siete (aluminio, arsénico, cromo, cobalto, hierro, manga-neso y vanadio) se identificaron como COPC en la super-ficie y el subsuelo en el área de la Puerto Rico Beverage. Cinco compuestos orgánicos volátiles (COV) (cis-1,2-dicloroetano, tetracloroetano, trans-1,2-dicloroetano tri-cloroetano, y cloruro de vinilo) y nueve inorgánicos (aluminio, arsénico, bario, cromo, cobalto, cobre, hierro, manganeso, y vanadio) se identificaron como COPC en el agua subterránea. Dos COV (bromodiclorometano y dibromoclorometano) y seis inorgánicos (arsénico, cromo, cobalto, hierro, man-ganeso, y vanadio) se identificaron como COPC en el sedimento del Río Maunabo. Las vías de exposición evaluadas para el suelo incluyen la ingestión y el contacto dérmico con el suelo, la inhala-ción de partículas del suelo por parte de los trabajadores industriales/comerciales, intrusos, residentes y trabajado-res de la construcción. Las vías de exposición evaluadas incluyen la ingestión y el contacto dérmico con el agua subterránea, la inhalación del vapor emitido durante una ducha o el baño, y la inhalación del vapor a través de la intrusión de trabajadores comerciales/industriales y resi-dentes. Las vías de exposición evaluado para el agua de superficie y sedimento incluye la ingestión de o el con-tacto dérmico de los usuarios recreacionales. Para los escenarios actuales y futuros del uso de terreno, el total estimado de los riesgos de cáncer están dentro del rango establezido por la EPA (riesgo de cáncer de 1x10 -6 a 1x10 - 4) para los receptores bajo el escenario de Riesgo Máximo de Exposición (RME por sus siglas en inglés) para todos los receptores bajo el escenario del RME, con excepción de los residentes de la Antigua Central Azucarera y la Puerto Rico Beverage. Sin em-bargo, bajo el escenario de Tendencia Central de Exposi-ción (CTE por sus siglas en inglés), el total de riesgos de cáncer están dentro del rango establecido por la EPA de 1x10 - 6 a 1x10 - 4.

El archivo del expediente administrativo, que contiene la información sobre la cual se basará la selección de la respuesta de acción, estará disponible en los siguientes lugares: Casa Alcaldía de Maunabo Maunabo, PR (787) 861-1012 Horario: Lunes – Viernes de 9:00am a 3:00 pm Agencia Federal de Protección Ambiental División del Caribe City View Plaza II – Oficina 7000 48 RD. 165 Km. 1.2 Guaynabo, P.R. 00968-8069 (787) 977-5865 Horario: Lunes - Viernes 9:00 a.m. a 5:00 p.m. Por cita Junta de Calidad Ambiental de Puerto Rico Programa de Respuesta de Emergencia y del Superfondo Edificio de Agencias Ambientales Cruz A. Matos Urbanización San José Industrial Park 1375 Avenida Ponce de León San Juan, PR 00926-2604 (787)767-8181 ext. 3207 Horario: Lunes – Viernes 9:00am a 3:00 pm Por cita U.S. EPA Records Center, Region 2 290 Broadway, 18th Floor. New York, New York 10007-1866 (212) 637-4308 Horario: Lunes-Viernes - 9 am a 5 pm Por cita.

R2-0002646

PLAN PROPUESTO


8

¿QUÉ ES EL RIESGO Y CÓMO SE CALCULA? Una evaluación de riesgos humanos, es un análisis de los efectos adversos potenciales a las saludes causadas por la liberación de sustancias peligrosas de un lugar en ausencia de acciones para controlar o mitigar los mismos bajo los actuales y futuros usos del terreno. Un proceso de cuatro pasos se utiliza para evaluar los riesgos humanos de salud relacionados con el lugar para situa-ciones razonables de exposición máxima. Identificación de riesgos: En este paso, los contaminantes de interés en el lugar en distintos medios (es decir, el suelo, las aguas subterráneas, aguas superficiales, y el aire) se identifican en función de factores tales como la toxicidad, la frecuencia de ocurrencia, y el destino y transporte de los contaminantes en el medio ambiente, las concentraciones de los contaminantes en los medios específicos, la movilidad, persistencia y bioacumulación. Evaluación de la Exposición: En este paso, se evalúan las vías de exposición diferentes a través de las cuales las personas pue-den estar expuestas a los contaminantes identificados en el paso anterior. Ejemplos de las vías de exposición son la ingestión acci-dental de y el contacto dérmico con el suelo contaminado. Los factores relacionados con la evaluación de la exposición incluyen, pero no se limitan a, las concentraciones a las cuales se pueden exponer las personas y la posible frecuencia y duración de la exposición. Al usar estos factores, el escenario de “exposición máxima razonable" se calcula y se muestra el más alto nivel de exposición humana que razonablemente podía esperarse que se produzca. Evaluación de Toxicidad: En este paso, se determinan los tipos de efectos adversos para la salud asociados con exposiciones químicas y la relación entre la magnitud de la exposición (dosis) y la gravedad de los efectos adversos (de respuesta). Los efectos potenciales sobre la salud son los productos químicos específicos y pueden incluir el riesgo de desarrollar cáncer durante toda la vida u otro tipo de efectos no cancerígenos en la salud, tales co-mo cambios en las funciones normales de los órganos dentro del cuerpo (por ejemplo, los cambios en la eficacia del sistema inmu-nitario). Algunos productos químicos son capaces de causar cáncer y efectos no cancerígenos en la salud. Caracterización del riesgo: Este paso sintetiza y combina infor-mación sobre la exposición y las evaluaciones de toxicidad para realizar una evaluación cuantitativa de los riesgos en el lugar. Se evalúan los riesgos en función del riesgo potencial de desarrollar cáncer y el potencial de riesgos para la salud no cancerígenos. La probabilidad de que una persona manifieste cáncer se expresa como una probabilidad. Por ejemplo, un riesgo del cáncer de 104 significa uno "en diez mil es el riesgo de contraer cáncer en exce-so", o un caso adicional de cáncer puede ser visto en una pobla-ción de 10,000 personas como consecuencia de la exposición a los contaminantes de la ubicación bajo las condiciones ya expues-tas en la Evaluación de la Exposición. Las actuales directrices del Superfondo para las exposiciones aceptables son un riesgo de por vida individuales de cáncer en exceso en el rango de 104 hasta 106 (que corresponde a una entre diez mil a uno en un millón de riesgo de cáncer en exceso). Para los efectos sobre la salud no cancerígenos se calcula un índice de peligrosidad "(HI). Un HI representa la suma de los niveles de exposición individual en comparación con las dosis de referencia correspondiente. El concepto clave para una HI no cancerígeno es que un “nivel de umbral” (medida como un HI de menos de 1) exista por debajo del cual no se espera que ocurran los efectos no cancerígenos. .

Para los escenario actuales y futuros del uso de terreno, el total de riesgos a la salud que no sean cáncer están dentro de los límites establecidos por la EPA (HI de 1) para to-

dos los receptores bajo el RME, con excepción de los trabajadores comerciales e industriales, trabajadores de la construcción y residentes tanto de la Antigua Central Azucarera y la Puerto Rico Beverage. Los actuales y fu-turos trabajadores comerciales/industriales, trabajadores de la construcción y residentes tienen un Índice de Riesgo cáncer no incluido (HI por sus siglas en inglés) que exce-de el límite por unidad establecido por la EPA de del RME para los riñones, sistema respiratorio, pulmones, y el tracto gastrointestinal (GI). Los riesgos a la salud, sin incluir cáncer, para los actuales y futuros trabajadores comerciales/industriales y trabajadores de la construcción están casi en su totalidad está fundado hipotéticamente en el agua subterránea como agua potable. Para los residen-tes actuales y futuros, el potencial de riesgos a la salud de los riñones es el resultado de la exposición al cis‐1,2‐DCE y al vanadio en el agua subterránea, mientras que los potenciales efectos adversos al sistema respiratorio son el resultado de la exposición al vanadio en el suelo y en el agua subterránea. El efecto potencial adverso a los pulmones y al tracto gastrointestinal (GI) es mayormente el resultado de la exposición al arsénico y al hierro, respectivamente, tanto en el suelo como en el agua subterránea. En el escenario del CTE, el HI todavía ex-cede el límite de unidad establecido por la EPA para el mismo objetivo enórganos/efectos, con excepción de los pulmones y el tracto gastrointestinal, afectado por el RME.

Escenarios de Riesgos de Cáncer (Escenario Actual)

Escenario Área Riesgo

Trabajadores Comerciar-les e Industriales

Antigua Central Azucarera PR Beverage

4 x 10-5

4 x 10-5

Intrusos Antigua Central Azucarera PR Beverage

9 x 10-7

1 x 10-6

Residentes Antigua Central Azucarera

2 x 10-4

(RME) 8 x 10-5 (CTE)

Usuarios Recreacionales Río Maunabo 9 x 10-7

R2-0002647

PLAN PROPUESTO


9

Escenarios de Riesgos de Cáncer (Escenario Futuro)

Escenario Área Riesgo

Residentes PR Beverage

Río Maunabo

2 x 10-4

(RME) 8 x 10-5 (CTE) 2 x 10-5

Futuros Trabajadores de la Construcción


2 x 10-7

8 x 10-8

Escenarios de Riesgos a la Salud que no sean Cáncer

(Escenario Actual)

Escenario Área Índice de Peligro

Trabajadores Comerciales e Industriales


Total: 5 (RME) Riñones: 5 Sistema Respiratorio: 4 Total: 4 (CTE) Riñones: 3 Sistema Respiratorio: 3 Total: 5 (RME) Riñones: 4 Sistema Respiratorio: 4 Total: 3 (CTE) Riñones: 3 Sistema Respiratorio: 3

Intrusos Antigua Central Azucarera PR Beverage

Total: 0.8 Total:0.7

Residentes Antigua Central Azucarera

Total: 36 (RME) Riñones: 32 Sistema Respiratorio: 30 Pulmones: 2 Tracto GI*: 2 Total: 16 (CTE) Riñones: 14 Sistema Respiratorio: 13

Usuarios Re-creacionales

Río Maunabo Total: 1

* GI = Gastrointestinal

Escenarios de Riesgos ala Salud que no sean Cáncer (Escenario Futuro)

Escenario Área Índice de Peligro

Residentes PR Beverage

Río Maunabo

Total: 34 (RME) Riñones: 31 Sistema Respirato-rio: 4 Pulmones : 2 Tracto GI*: 2 Total: 15 (CTE) Riñones: 13 Sistema Respirato-rio: 13 Total: 0.007

Trabajadores de la Cons-trucción

Antigua Central Azucarera

Total: 2 Riñones: 2 Sistema Respirato-rio: 2

PR Beverage Total: 2 Riñones: 2 Sistema Respirato-rio: 2

* GI = Gastrointestinal Detección del Nivel de Evaluación de Riesgo Ecológico

Basado en una comparación de las concentraciones máximas detectadas de los contaminantes del Lugar en el suelo, sedimento, agua de superficie, y agua entre poros derivada de forma conservadora de los Niveles de Selec-ción Ecológica (ESLs por sus siglas en inglés), el poten-cial de riesgo ecológico puede ocurrir. Los químicos de potencial preocupación (COPCs por sus siglas en inglés) identificados en el Lugar por medio son:

Suelo: cadmio, cromo, cobre, plomo, manganeso, mercurio, vanadio, y zinc

Sedimento: cobre Agua de superficie: bario Agua Porosa: aluminio, bario, y hierro

Los siguientes contaminantes (COV y metales) me-dio‐específicos se retuvieron como COPC debido a la falta de ESL medio - específico.

Suelo: carbazol

R2-0002648

PLAN PROPUESTO


10

Sedimento: bario y vanadio Agua de superficie: bromodiclorometano y di-

bromoclorometano. Los organismos o grupos representativos de organismos pueden estar expuestos a contaminantes por medio del contacto directo y/o la ingestión de medios contaminados o a través de sus presas. Aunque varios escenarios po-tenciales de exposición pueden ser identificados por los receptores ecológicos, es más apropiado enfocar la eva-luación sobre escenarios de exposición críticos o aquellos que más pueden contribuir. Por lo tanto, el Evaluación de Riesgo Ecológico por Detección (SLERA) se enfocó en el escenario de exposición por contacto directo. Los puntos finales de evaluación y medición fueron iden-tificados y enfocados colectivamente en los organismos potenciales en el Lugar utilizando hábitat acuático y te-rrestre. Para propósito del SLERA, las concentraciones máximas de contaminantes detectadas en el suelo, sedi-mento, agua entre poros y de superficie sirvieron como punto de concentraciones de exposición y se evaluó a través de la exposición específica directa. Los químico-especificos y los medio-específicos ESL sirven como efecto concentraciones. La comparación de estos dos valores se utilizó para estimar el riesgo. Es criterio actual de la EPA que la Alternativa Preferida identificada en este Plan Propuesto, o una de las otras alternativas consideradas, es necesaria para proteger la salud pública, el bienestar y el medio ambiente de emi-siones reales o amenazas de sustancias peligrosas al me-dio ambiente. Los COPC obtenidos a través de la comparación con sus respectivos medio-específicos, los ESL estaban todos compuestos de metales. No hay productos químicos rela-cionados con el Lugar (p. ejemplo, el PCE y el DCE) que fueran detectados en algún medio evaluado en este SLE-RA. Estos metales detectados conservadoramente por encima de los ESL son muy probablemente reflejode condiciones naturales o no relacionadas a fuentes del Lu-gar. Por lo tanto el Lugar no representa ningún riesgo actual a las comunidades ecológicas. OBJETIVOS DE ACCIONES CORRECTIVAS Los objetivos de acciones correctivas (RAO por sus si-glas en ingles) son metas específicas para proteger la sa-lud humana y el medioambiente. Estos objetivos están basados en la información y normas disponibles, tales como los requisitos apropiados, aplicables o relevantes

(RAAR), guia-para-considerar y niveles de riesgos es-pecíficos del Lugar. Los RAO para el Lugar son:

Proteger la salud humana con la prevención de exposición a través de ingestión, inhalación o contacto dérmico con agua subterránea contami-nada con concentraciones por encima de las Me-tas de Remediación Preliminares (MRP); y

Remedial las aguas subterráneas en la medida posible mediante la reducción de las concentra-ciones de contaminantes del Lugar hasta las MRP.

El agua subterránea contaminada es el medio de interés para el Lugar. Las muestras de subsuelo y suelo de su-perficies recopiladas durante el RI no identificaron una fuente de COV relacionada con el Lugar. Los contami-nantes relacionados con el Lugar son compuestos alifáti-cos clorinados incluyendo el PCE, TCE, cis‐1,2‐DCE, 1,1‐DCE, y compuestos volátiles. Estos contaminantes son COV y pueden representar riesgos a la salud humana a través de la inhalación, ingestión y contacto dérmico. Basándose en los datos recopilados del agua subterránea durante el RI, hay tres plumachos separados en el Lugar (Figura 3). Estos tres plumachos están ubicados en dife-rentes áreas del Lugar y tienen perfiles característicos de los contaminantes. El plumacho de cis‐1,2‐DCE está localizado entre el área PRB y el pozo de suministro público Maunabo #1. El plumacho de PCE está localiza-do entre el área de FSM y el pozo de suministro público Maunabo #1. El plumacho de 1,1‐DCE está localizado al noroeste del pozo de suministro público Maunabo #4. Los plumachos de aguas subterráneas están dentro del “Wellhead Protection Area” y los pozos de suministro público (Maunabo #1 y Maunabo #4) se encuentran ope-rando actualmente. Resumen de Alternativas Correctivas Las alternativas correctivas se agruparon al combinar las tecnologías correctivas y las opciones de operación para cada medio contaminado. Las alternativas remediales para manejar la contaminación en cada uno de los tres plumachos están resumidas más adelante. La alternativa propuesta para el Lugar, es la Alternativa 3: Extrusión por Aeriación/Extrusión de Vapor de Suelos (AS/SVE por

sus siglas en ingles) y Monitoreo y Atenuación Natural (MNA por sus siglas en inglés).

R2-0002649

PLAN PROPUESTO


11

Alternativa 1: No Requiere Acción

La alternativa de No Requiere Acción se conserva para propósitos de comparación según lo requiere la NCP. Ninguna acción remedial se llevaría a cabo como parte de esta alternativa. No incluye ningún control institucional o programas de monitoreo. Las revisiones cada cinco años se llevarían a cabo por la EPA para evaluar las con-diciones del Lugar. No incluye ningún costo en el Estu-dio de Viabilidad para las revisiones ya que las llevaría a cabo la EPA. Debido a CERCLA, las alternativas que mantengan con-taminantes por encima de los niveles permitidos para el uso no restringido y la exposición ilimitada requieren que el Lugar sea revisado cada cinco años. Si la revisión lo justifica, acciones remediales adicionales pueden imple-mentarse para remover, tratar o controlar la contamina-ción. La revisión del Lugar incluirá una inspección vi-sual de todo el Lugar y un informe preparado por la EPA. Alternativa 2: Monitoreo de la Atenuación Natural

(MNA por sus siglas en inglés)

Alternativa 2 - El Monitoreo de la Atenuación Natural (MNA por sus siglas en inglés) se basa en mecanismos destructivos de origen natural (biodegradación) para tra-tar los plumachos cis‐1,2‐DCE y 1,1‐DCE y los meca-nismos no destructivos (dilución y dispersión) para tratar el plumacho PCE. El monitoreo rutinario y el análisis de la tendencia de la concentración del contaminante, se lle-van a cabo generalmente como parte de la acción de res-puesta de la MNA para demostrar que los contaminantes no representan riesgo significativo y que la degradación está ocurriendo. Si el monitoreo indica que los niveles no están disminuyendo lo suficientemente, se debe imple-mentar un plan de contingencia. Si se logra un nivel asintótico de concentración de contaminantes, un remedio activo (p.ej., inyecciones en lugares claves, etc.) pudieran ser necesarias para logra los MRP. La alternativa 2 consiste en las siguientes actividades principales:

Investigación prediseño/estudio MNA Controles institucionales Monitoreo a largo plazo Revisión cada cinco años

Para ayuda a entender la incertidumbre en torno a la re-ducción de la concentración de contaminantes a través de MNA, se requiere un estudio/investigación de MNA a fin de proporcionar la información para proyectar mejor la

efectividad de los mecanismos de atenuación natural en el campo y para confirmar que la degradación activa de los contaminantes está ocurriendo donde se necesita. Los controles institucionales deberán restringir el uso futuro del Lugar y las aguas subterráneas, y se deben re-querir precauciones para proteger la salud humana en caso de que las medidas correctivas se vean perturbadas. El monitoreo a largo plazo de las aguas subterráneas del Lugar puede implementarse cuando los contaminantes se mantengan por encima de los niveles que permite el uso y la exposición ilimitada. El programa de monitoreo de-berá continuar hasta que las concentraciones se han esta-bilizado o se haya alcanzado las metas remediales. De acuerdo con CERCLA, las alternativas que resulten en contaminantes por encima del nivel permitido para el uso y la exposición ilimitada requieren que el Lugar sea revisado cada cinco años. Si la revisión lo justifica, ac-ciones remediales adicionales pueden ser implementadas para remover, tratar o contener la contaminación. La re-visión del Lugar incluirá una inspección visual de todo el Lugar y un informe preparado por la EPA. Alternativa 3: Extrusión por Aeración/Extrusión de Vapor de Suelos (AS/SVE por sus siglas en inglés) y Monitoreo y Atenuación Natural (MNA) Penacho PCE

y1,1,-DCE . Bajo la Alternativa 3, el MNA sería implantado para los plumachos del PCE y del 1,1‐DCE según se presentan en la Alternativa 2. Además, bajo esta alternativa, la aera-ción se utilizaría para sustraer los COV de las aguas sub-terráneas en el plumacho cis‐1,2‐DCE y reducir las con-centraciones por debajo de los MRP. Una cuadrícula de puntos de aeración se instalaran en áreas donde el movimiento delagua subterránea es lento - relativamente lejos del pozo de bombeo, y una hilera de puntos de aeración (una cortina de aeración) se instalará cerca del pozo en las áreas donde el agua subterránea se mueve con más rapidez. Cada punto de aeración se su-pone tenga un radio de influencia de 10 pies. Esta confi-guración es considerada por ser costo efectivo y de des-empeño óptimo, comparada con una configuración que conste únicamente de una cuadrícula de puntos de aera-ción a lo largo de todo el plumacho. Se implementará un sistema SVE en la zona vadoza para recopilar los COV que se liberen del agua subterránea por el sistema de aeración. Cabe señalar que, dado que las

R2-0002650

PLAN PROPUESTO


12

concentraciones en el agua subterránea son bajas, la masa recolectada por el sistema SVE sería muy baja, y poten-cialmente por debajo de los límites de detección en el sistema efluente si se recogiesen las muestras. Además, la biodegradación en las condiciones aeróbicas creadas por el sistema de aeración y también en la zona vadosa, reduciría la masa de cis‐1,2‐DCE y VC para que la pueda capturar el SVE. Se requerirá una prueba piloto de Sistema de Aeración para determinar el radio de influencia de cada localiza-ción de aeración y el pozo de extracción de vapor de sue-lo, y por consiguiente el número de puntos de aeración necesarios. La prueba piloto también evaluará la necesi-dad del tratamiento de los vapores recolectados. Los datos obtenidos durante el RI, del estudio prediseño de la investigación/MNA, y el estudio piloto AS se utili-zarán para desarrollar un enfoque detallado para la reme-diación del Lugar durante el diseño. Todos los aspectos necesarios para la implementación de la acción remedial considera, incluyendo, pero sin limitar: un diseño detalla-do de la estrategia de tratamiento y sistema, la secuencia de construcción, los requisitos reglamentarios y los esti-mados de costo. Se instalará una cortina de aeración en la pendiente as-cendente de Maunabo #1 y una cuadrícula de puntos de aeración se instalará en la porción de la pendiente ascen-dente del plumacho cis‐1,2‐DCE. Los pozos SVE se ins-talarán para recolectar los vapores de aeración en la zona vadosa. El vapor recolectado se libera directamente a la atmósfera. La cuadrícula de aeración operará por un año y la cortina de aeración operara por tres años. El monito-reo del desempeño se llevará a cabo en los pozos de agua subterránea instalados en la cuadrícula de aeración, al igual que en la pendiente ascendente y descendente de la cortina de aeración. El estudio prediseñado de la investigación/MNA, los con-troles institucionales, el monitoreo a largo plazo, y las actividades de revisión cada cinco años son similares a las descritas en la Alternativa 2. Alternativa 4: Bioremediación In-situ, (Penacho

cis‐1,2‐DCE) Monitoreo de la Atenuación Natural (MNA) (Penachos PCE y 1,1‐DCE)

Bajo esta alternativa, la bioremediación in-situ podría realizarse dentro del contorno de 70 μg/L en el plumacho cis‐1,2‐DCE, con controles institucionales para la pro-

tección de la salud humana. Un programa de monitoreo a largo plazo podría implementase para asegurar que la migración adicional de COPC no esté ocurriendo. Los resultados de un programa de monitoreo a largo plazo apoyará las decisiones sobre la implementación de con-troles institucionales. Como parte del proceso de biore-mediación, EHC® será utilizado como parte de la solu-ción representativa. Un estudio microcosmo se llevará a cabo en el plumacho. El estudio del microcosmo eva-luará la efectividad del EHC® y otras soluciones tales como el lactato/suero, con el fin de seleccionar la(s) solu-ción(s) más costo-efectiva para este Lugar. Es posible que se necesite llevar a cabo un estudio piloto antes del diseño remedial para obtener los parámetros de diseño específicos del Lugar para la implementación a gran esca-la de la bioremediación. Una investigación prediseño se llevará a cabo para definir con más precisión la extensión vertical y lateral de la zona de tratamiento en el pluma-cho. La bioremediación in-situ del plumacho cis‐1,2‐DCE se llevará a cabo mediante la inyección de la solución EHC® en forma de bio-barreras en el área de tratamiento, delineadas durante la investigación predi-seño. Cada bio-barrera consistiría en una serie de puntos de inyección que inyectarían la solución EHC® en el plumacho. La solución puede ser inyectada utilizando la tecnología de empuje directo o en puntos permanentes de inyección. En base a las bajas concentraciones de conta-minantes, sólo una ronda de inyecciones de solución podría ser necesaria. Las condiciones de reducción crea-das por la inyección de la solución potencialmente au-mentaría la atenuación natural de los contaminantes res-tantes de baja concentración cercanos al área de trata-miento. En los plumachos de PCE y 1,1‐DCE, el MNA se basó para asegurar que la remediación del agua subterránea RAO se logre, según se describe en la alternativa 2. Los controles institucionales tales como las restricciones de las escrituras y restricciones sobre la perforación de po-zos será implantará para eliminar las rutas de exposición de agua contaminada a los receptores. El monitoreo a largo plazo involucraría el muestreo de agua subterránea anual y la revisión periódica de éstas para monitorear y evaluar la emigración y cambios en la concentración en el acuífero. La Alternativa 4 incluye los siguientes componentes:

Investigación Prediseño Estudio microcosmo y estudio piloto Diseño Remedial Bioremediación In‐situ del plumacho

cis‐1,2‐DCE

R2-0002651

PLAN PROPUESTO


13

Controles institucionales Monitoreo a largo plazo Revisiones cada cinco años

Según CERCLA, las alternativas que resulten en conta-minantes sobre el nivel permitido para el uso no restrin-gido y la exposición ilimitada requeridas para el Lugar, deben ser revisadas al menos una vez cada cinco años. Si la revisión lo justifica, acciones correctivas adicionales se pueden implementar para remover, tratar o detener la contaminación. La revisión del Lugar incluirá una ins-

pección visual de todo el Lugar y un informe preparado por la EPA. Evaluación de Alternativas Remediales Existen nueve criterios del Superfondo que son utilizados para evaluar las diferentes alternativas de forma indivi-dual y en comparación una contra otra para la selección de la mejor alternativa. Cada alternativa ha sido evaluada contra estos nueve criterios y comparada con las otras alternativas bajo consideración. La evaluación de alter-nativas en relación con los nueve criterios se analiza a continuación. Un análisis más detallado de las alternati-vas presentadas se puede encontrar en el informe del Es-tudio de Viabilidad.

1. Protección Total de la Salud Humana y el Medio Ambiente

La Alternativa 1 no cumple con los RAO y no sería de protección a la salud humana y ni al medio ambiente ya que ninguna acción sería tomada. La contaminación per-manecería en el agua subterránea, mientras que ningún mecanismo se implementaría para prevenir la exposición al agua subterránea contaminada, o para reducir la toxici-dad, movilidad, o volumen de contaminación excepto a través de procesos naturales de atenuación que no serán monitoreados para evaluar la eficacia o predecir la dura-ción de esta alternativa. La Alternativa 2 cumpliría con los RAO. Es importante señalar que a pesar de que los datos históricos en Maunabo #1 no han demostrado con-taminantes por encima de los MCL desde el 2006, el plumacho cis‐1,2‐DCE está dentro de la zona de captura de Maunabo #1. Si la atenuación natural no ocurre de-ntro de un periodo de tiempo razonable, existe el poten-cial de que las concentraciones sobre los MRP que están actualmente en el plumacho podrían entrar al pozo de suministro Maunabo #1 en el futuro, impactando poten-cialmente la salud humana. La recolección de datos adi-cionales será necesaria para confirmar que esas concen-traciones están disminuyendo a través de la atenuación natural y los MRP se cumplirían dentro de un periodo de tiempo razonable. Lo mismo ocurre para los plumachos de PCE y 1,1‐DCE, es incierto si la atenuación natural se está produciendo a un ritmo suficientemente grande como para reducir permanentemente las concentraciones por debajo de los MRPS dentro de un periodo razonable de tiempo. Las Alternativas 3 y 4 cumplen con los RAO. El sistema de AS/SVE para la Alternativa 3 y las bio-barreras en la Alternativa 4; cada una sirve para reducir la concentración de contaminantes en el agua subterránea que se saca del pozo de suministro Maunabo #1, prove-

LOS NUEVE CRITERIOS DE EVALUACIÓN DEL SUPERFONDO

1. Protección general de la salud humana y el medio am-biente evalúa si una alternativa elimina, reduce o controla las amenazas para la salud pública y el medio ambiente a través de controles institucionales, los controles de ingeniería o tratamien-to. 2. Cumplimiento con los Requisitos Apropiados Aplicables o Relevantes (ARAR) evalúa si la alternativa cumple con las leyes y regulaciones ambientales federales y estatales, y otros requisitos que pertenecen a la ubicación, o si se justifica una exención de los mismos. 3. Efectividad y Permanencia a Largo Plazo considera la posi-bilidad de una alternativa para mantener la protección de la sa-lud humana y el medio ambiente a través del tiempo. 4. Reducción de Toxicidad, Movilidad, o Volumen (TMV) de Contaminantes a Través del Tratamiento evalúa la utilización alterna de tratamiento para reducir los efectos nocivos de los contaminantes principales, su capacidad para moverse en el ambiente, y la cantidad de contaminación presente. 5. Efectividad a Corto Plazo considera la duración del tiempo necesario para ejecutar una alternativa y los riesgos que la alter-nativa plantea a los trabajadores, la comunidad y el medio am-biente durante su ejecución. 6. Implementabilidad considera la viabilidad técnica y adminis-trativa de la aplicación de alternativas, incluyendo factores tales como la disponibilidad relativa de bienes y servicios. 7. Costo incluye estimados de capital y de operaciones y man-tenimiento anual, así como el valor presente. Valor actual de costos es el costo total de una alternativa más el tiempo en términos de valor en dólares de hoy. Los estimados de gastos se espera que sean precisos en un marco de +50 a -30 por ciento. 8. Aceptación Estado/Agencia de Apoyo considera si el Esta-do está de acuerdo con los análisis Y recomendaciones de la EPA, tal como se describen en el RI/FS y el Plan Propuesto. 9. Aceptación de la Comunidad considera si la comunidad local está de acuerdo con los análisis de la EPA y la alternativa preferida. Observaciones recibidas sobre el Plan Propuesto son un indicador importante de la aceptación de la comunidad.

R2-0002652

PLAN PROPUESTO


14

yendo una protección inmediata a la salud humana. Sólo las bio-soluciones que sean seguras para inyectarse en el acuífero cerca de un pozo de suministro, serán considera-das y se evaluarán más a fondo durante el estudio de mi-crocosmo. Las Alternativas 2, 3, y 4 proveen controles adecuados a los riesgo para las salud humana al imple-mentar los controles institucionales y de ingeniería. 2. Cumplimiento con los Requisitos Apropiados y

Relevantes (ARRA por sus siglas en inglés) La Alternativa 1 no lograría los químico-específicos ARAR para el agua subterránea. La ubicación y la ac-ción específica de los ARAR no aplican a esta alternativa ya que no se llevará a cabo ninguna acción remedial. Para la Alternativa 2, la recolección de datos sería nece-saria para confirmar la capacidad de atenuación natural para reducir concentraciones y cumplir con los ARAR. Si la atenuación natural no ocurre dentro de un periodo de tiempo razonable, los ARAR no se alcanzarán. Esto también es cierto para los plumachos de PCE y de 1,1‐DCE de las Alternativas 3 y 4. Para el plumacho cis‐1,2‐DCE, estas dos alternativas cumplen con los quí-micos-específicos de ARAR en un término a largo plazo debido a la implementación de AS/SVE o del proceso de tratamiento in‐situ que reduciría considerablemente las concentraciones de contaminantes en el área de trata-miento. No existen ARAR específicos para este Lugar. Las Alternativas 2 a la 4 cumplirían con la acción-específica ARAR. 3. Eficacia y Permanencia a Largo Plazo La Alternativa 1 no sería eficaz ni permanente ya que no habría mecanismos para prevenir la exposición al agua subterránea contaminada. La Alternativa 2 proveería una eficacia y permanencia a largo plazo al confiar en la ate-nuación natural para reducir permanentemente las con-centraciones de contaminantes en los tres plumachos. Sin embargo, para los plumachos cis‐1,2‐DCE y 1,1‐DCE, es incierto si la atenuación natural está ocu-rriendo a un ritmo lo suficientemente grande como para reducir las concentraciones por debajo de los MRP dentro de un periodo de tiempo razonable. Las Alternativas 3 y 4 difieren de la Alternativa 2 en que estas alternativas ofre-cen una efectividad y permanencia a largo plazo al plu-macho de cis‐1,2‐DCE mediante el uso del tratamiento in‐situ para reducir la masa contaminante en el área de tratamiento. Las Alternativas 3 y 4 podrían proporcionar la mayor reducción de masa de contaminación dentro del plumacho cis‐1,2‐DCE dentro de un periodo de tiempo menor. Las bajas concentraciones restantes de contami-

nantes en los tres plumachos we reducirian a través del proceso de atenuación natural. Los controles Institucio-nales de las Alternativas 2, 3 y 4 podrían evitar la exposi-ción de las aguas subterráneas contaminadas mientras se restaura la calidad de las aguas subterráneas a través del proceso de atenuación natural. La eficacia a largo plazo de la alternativa seleccionada será evaluada a través del monitoreo rutinario de las aguas subterráneas y las revi-siones cada cinco años. 4. Reducción de la Toxicidad, Movilidad o Volumen a

través del Tratamiento La Alternativa 1 podría no reducir el contaminante de toxicidad, movilidad o volumen (T/M/V) ya que no se llevaría a cabo ninguna acción remedial. Para la Alterna-tiva 2, el volumen total de agua subterránea contaminada en los tres plumachos podría aumenta si el proceso de atenuación natural no puede detenerse en el plumacho. El alcance y la eficacia de la reducción de toxicidad a través de la atenuación natural, especialmente la trayecto-ria de la bio-degradación de contaminantes clorinados, tendrán que ser verificados con la recopilación de datos adicionales. Las Alternativas 3 y 4 serían las más efica-ces para reducir la toxicidad y el volumen de contamina-ción a través del tratamiento en el plumacho cis‐1,2‐DCE. Por otra parte, la cortina de aeración (Al-ternativa 3) y las bio-barreras (Alternativa 4) podrían ser-vir para limitar la movilidad del plumacho cis‐1,2‐DCE más allá de su radio actual. En el plumacho 1,1‐DCE, la movilidad no se reducirá a través de la Alternativa 3 o 4. Sin embargo, la toxicidad y el volumen se reduciran po-tencialmente por la biodegradación. El T/M/V no se re-duciría en el plumacho PCE ya que los mecanismos de atenuación natural serían de dilución y dispersión, y no de biodegradación. 5. Eficacia a Corto Plazo Con respecto a la Alternativa 1, no habría ningún impacto a corto plazo a la comunidad y el medio ambiente ya que no se tomaría ninguna acción remedial. Para que un mo-nitoreo a largo plazo se lleve a cabo en una propiedad privada, se tiene que obtener de los dueños de la propie-dad acceso y las coordinaciones tendrán que ser a través de los mismos. Habrá impactos a corto plazo para la co-munidad local y los trabajadores en las Alternativas 3 y 4 en el plumacho cis‐1,2‐DCE debido a las medidas reme-diales que se llevan a cabo y que estén asociadas con la construcción, la operación y/o las actividades de inyec-cion. El implementar los MNA en el plumacho PCE y

R2-0002653

PLAN PROPUESTO


15

1,1‐DCE no sería eficaz a corto plazo, ya que la eficacia se basaría en la dilución y la dispersión creada por el flu-jo del agua subterránea y la biodegradación natural para reducir las concentraciones MRP. El monitoreo del aire, los controles de ingeniería y uso apropiado de PPE por trabajadores se utilizarán para proteger la comunidad y los trabajadores en las Alternativas 2 a la 4. 6. Implementabilidad La Alternativa 1 sería la más fácil técnica y administrati-vamente de implementar ya que no se llevará a cabo ningún trabajo adicional en el Lugar. Las Alternativas 2 a la 4 serían técnicamente implementadas ya que los ser-vicios, materiales y vendedores experimentados estarían disponibles. Los estudios pilotos y la plataforma serán implementados para obtener parámetros de diseño especí-ficos del Lugar. Se necesitaran acuerdos de acceso para implementar la alternativa seleccionada en las propieda-des privadas. También se requeriría un permiso para in-yectar la solución de bioremediación en el subsuelo y/o descargar vapor del sistema de aeración a la atmosfera (si se requiere). En general, la Alternativa 4 sería la más difícil de implementar, seguida de la Alternativa 3 y lue-go la Alternativa 2. 7. Costo No hay ningún costo asociado con la Alternativa 1. El valor total de la Alternativa 2 es de $2.4 millones. El valor total actual de la Alternativa 3 es de $4.6 millones. El valor total actual de la Alternativa 4 es de $4.5 millo-nes. 8. Aceptación de la Agencia Estatal/de Apoyo El Estado Libre Asociado de Puerto Rico está de acuerdo con la alternativa preferida en este Plan Propuesto. 9. Aceptación de la Comunidad La aceptación de la comunidad de la alternativa preferida será evaluada después que termine del periodo de comen-tarios públicos y se describirá en la sección del Registro de Decisiones para este Lugar. El Registro de Decisiones es el documento que formaliza la selección de una solu-ción para el lugar. RESUME DE LA ALTERNATIVA PREFERIDA

Alternativa 3: Extrusión por Aeración/Extrusión de Vapor de Suelos (AS/SVE por sus siglas en inglés) y Monitoreo y Atenuación Natural (MNA) Penacho PCE

y1,1,-DCE .

La Alternativa 3 consiste de las siguientes actividades principales:

Estudio prediseño de investigación/MNA Estudio piloto AS Diseño Remedial Instalación/operación de AS/SVE Controles Institucionales Monitoreo a largo plazo Revisión cada cinco años

Protección Total de la Salud Humana y el Ambiente Esta alternativa proveerá protección a la salud humana y al medio ambiente. La AS/SVE podrá eliminar los con-taminantes del plumacho cis‐1,2‐DCE permanentemente; las bajas concentraciones restantes de contaminantes se espera que se reduzcan a través de procesos naturales ta-les como la dilución, dispersión y la biodegradación. Durante la corrección, la exposición al agua subterránea en los tres plumachos - más allá de la ruta de exposición de los pozos de suministros existentes – será prevenida a través de controles institucionales. Esta alternativa cum-pliría con los RAO. Los controles institucionales elimi-naría la ruta de exposición para el agua subterránea con-taminada hacia los receptores locales antes de los RAO y los MRP se hayan logrado. Cumplimiento con los ARAR

La Alternativa 3 no cumplirá con los ARAR químicos específicos a corto plazo en el plumacho PCE y 1,1‐DCE debido a que las concentraciones COC continúen exce-diendo los MRP en el agua subterránea mientras la ate-nuación natural esté ocurriendo. Sin embargo, a través del tiempo en los tres plumachos, las concentraciones exis-tentes de COC podrían disminuir a niveles aceptables en un periodo de tiempo razonable ya sea por el AS/SVE o por atenuación natural. Si la atenuación natural no pro-cede efectivamente, será necesario implementar una ac-ción de contingencia para lograr los ARAR químicos es-pecíficos. Esta alternativa seguirá los requisitos de salud y seguridad para cumplir los ARAR de acción específica. No hay ARAR de ubicación específica para este Lugar. Eficacia y Permanencia a Largo Plazo

R2-0002654

PLAN PROPUESTO


16

Los AS/SVE removerán la contaminación de forma per-manente por extracción de contaminantes del agua sub-terránea. Es importante observar que la configuración propuesta de los puntos de aeración supone que Maunabo #1 continuará operando como opera en la actualidad. El diseño de cortina de aireación se propone con el fin que pueda aprovechar la pendiente hidráulica creada por el bombeo para halar el agua a la cortina de aeración en la zona de tratamiento. Si el pozo deja de bombear la corti-na todavía sería efectiva, pero el tratamiento podría tardar más tiempo ya que la velocidad del flujo del agua sub-terránea se reduciría. Un factor adicional a considerar es la biodegradación aeróbica. Ya que los compuestos volá-tiles y el cis‐ 1,2‐DCE se conoce que son degradables por bacterias aeróbicas, la introducción de oxígeno al acuífe-ro por el sistema de aeración estimularía el crecimiento de bacterias aeróbicas capaces de degradar estos dos compuestos. Los contaminantes que permanecen fuera de la zona de tratamiento son de bajas concentraciones y se reducen con el tiempo a través de la dilución y la dis-persión. En general, esta alternativa provee una correc-ción efectiva y permanente para el plumacho cis‐1,2‐DCE. Los procesos natrales tales como la dilu-ción, dispersión y la biodegradación reducirían las con-centraciones permanentemente en el plumacho PCE y 1,1‐DCE. Los controles institucionales podrían evitar la exposición al agua subterránea contaminada antes de que la calidad de la misma se restaure a MRP en cada uno de los tres plumachos. El programa de monitoreo a largo plazo y la revisión cada cinco años será para evaluar las condiciones de la contaminación y determinar el marco de tiempo operacional del remedio. Reducción de Toxicidad, Movilidad, o Volumen

(T/M/V) a través del Tratamiento

Esta alternativa reduciría significantemente el T/M/V de la contaminación en el plumacho cis‐1,2‐DCE. El volu-men y toxicidad del agua subterránea contaminada se reducirá al remover la contaminación del agua subterrá-nea y del suelo. La movilidad del vapor del suelo será controlada por el vacío aplicado al área de tratamiento, que evitaría la migración del vapor. En el plumacho 1,1‐DCE, la movilidad no se reduciría. Sin embargo, la toxicidad y el volumen se reducirían potencialmente por la biodegradación. Los T/M/V no se reducirían en el plumacho PCE ya que los mecanismos de atenuación na-tural serán diluidos y dispersados, y no la biodegradación.

Eficacia a Corto Plazo

Esta alternativa tendría unos impactos a corto plazo en la comunidad y el ambiente. Los AS/SVE tendrían que ins-talarse y operarse en el Lugar por aproximadamente tres años. La instalación del sistema se llevará a cabo sin ningún riesgo significante para la comunidad. Los traba-jadores del Lugar utilizarán vestimenta apropiada de PPE para minimizar la exposición a la contaminación y como protección a peligros físicos. Los AS/SVE serán efecti-vos a corto plazo. Los VC y cis-1,2-DCE son compues-tos volátiles que pueden ser retirados efectivamente del agua subterránea con aeración. Las condiciones aeróbi-cas en el agua subterránea creadas por el sistema de aera-ción inducirán un grado de biodegradación de los conta-minantes. La implementación del MNA en el plumacho PCE y 1,1-DCE no sería efectiva a corto plazo, ya que la efectividad se basaría en la dilución y dispersión creada por el flujo del agua subterránea y la biodegradación na-tural para reducir las concentraciones de MRP. Implementabilidad

El MNA y AS/SVE son tecnologías ya establecidas y fácilmente podrían implementarse en el Lugar. Esta alter-nativa requeriría el uso de construcción convencional de fácil disposición y equipos de perforación subterránea. El monitoreo del agua subterránea asociada al MNA podría fácilmente implementarse utilizando los servicios y mate-riales disponibles Costos

El valor total actual de la Alternativa 3 es de $4.6 millo-nes. El costo capital estimado es de $1.9 millones para los primeros 5 años, el estimado de O&M es de $0.6 mi-llones, y el costo de monitoreo es de $2 millones por 30 años. Estado/ Aceptación de la Agencia de Apoyo

El Estado Libre Asociado de Puerto Rico está de acuerdo con la alternativa preferida. Aceptación de la Comunidad

La aceptación de la comunidad de la alternativa preferida se evaluará después de que el período de comentarios públicos finalice.

R2-0002655

PLAN PROPUESTO


17

PARTICIPACIÓN DE LA COMUNIDAD

La EPA proveerá información relacionada con la limpie-za del Lugar de Contaminación de Aguas de Subterránea de Maunabo, para el público a través de vistas públicas, en los Récord Administrativos del Lugar y en anuncios publicados en los Periódicos La Esquina y El Nuevo Día. La EPA exhorta al público a obtener una comprensión más completa del Lugar y de las actividades realizadas en este lugar bajo Superfondo. Para más información sobre el Lugar, incluyendo la al-ternativa preferida de la EPA para el Lugar, favor comu-nicarse con:

Luis E Santos Gerente de Proyecto

(787) 977-5865

Brenda Reyes Relaciones con la

Comunidad (787) 977-5869

EPA – División de Protección Ambiental del Caribe

City View Plaza II – Oficina 7000 48 RD. 165 Km. 1.2

Guaynabo, P.R. 00968-8069 (787) 977-5865

O accesar la página de Internet de la EPA a: http://www.epa.gov/region02/superfund/npl/maunabo

Las fechas para el período de comentarios públicos; la fecha, el lugar y hora de la reunión pública, y el Lugar del Récord Administrativo se proporcionan en la página principal de esta hoja informativa. GLOSARIO Acción Remedial: una limpieza correctiva para tratar sustancias peligrosas en un lugar. Aguas subterráneas: El agua subterránea que se encuen-tra en los suelos y formaciones geológicas que están completamente saturados. ARAR: Requisitos aplicables o relevantes y apropiados. Estas son las normas ambientales federales o estatales y regulaciones que puedan concernir al Lugar o una alter-nativa en particular

Atenuación Natural (MNA): La atenuación natural aprovecha los procesos naturales para contener la conta-minación causada por derrames de productos químicos y reducir la concentración y la cantidad de contaminantes en los lugares afectados. CERCLA: La ley de Responsabilidad, Compensación y Recuperación Ambiental (Comprehensive Environmental Response Compensation and Liability Act, CERCLA por sus siglas en inglés). Una ley federal, conocida común-mente como el Programa "Superfondo", aprobada en 1980 que prevé las acciones de respuesta en las ubicacio-nes que se encuentran contaminadas con sustancias peli-grosas, y/o agentes contaminantes que ponen en peligro la salud pública y la seguridad o el medio ambiente. COPC: Químico de Potencial Preocupación. Costo Valor Presente: el costo total, en dólares actuales, de las medidas remediales. El valor del costo actual in-cluye los gastos de capital necesarios para aplicar las me-didas correctoras, así como el costo de operación a largo plazo, el mantenimiento y vigilancia. COV: Compuestos Orgánicos Volátiles. Tipo de produc-to químico que se evapora fácilmente, a menudo produ-ciendo un olor distinguible. EPA: Agencia de Protección Ambiental de los Estados Unidos. La agencia federal responsable de la administra-ción y la ejecución de CERCLA (y otras leyes y regla-mentos ambientales), y de la aprobación final para el ROD seleccionado. FS: Estudio de Viabilidad. Análisis de la viabilidad de varias opciones de medidas remediales para el Lugar. HHRA: Evaluación de Riesgo para la Salud Humana. Una Evaluación del Riesgo que representa para la Salud Humana si no se implementan las acciones correctivas. HI: Índice de Peligrosidad. Un número indicativo de efectos en la salud no cancerígenos qué es la relación en-tre el nivel existente de exposición y un nivel aceptable de exposición. Un valor igual o menor de uno indica que la población humana probablemente no experimente efec-tos adversos. HQ: Cociente de Peligrosidad. Se utiliza para evaluar efectos en la salud no cancerígenos y los riesgos ecológi-cos. Un valor igual o inferior a uno indica que la pobla-

R2-0002656



PLAN PROPUESTO


18

ción humana o ecológica no es probable que experimente efectos adversos. IC: Controles Institucionales. Métodos administrativos para evitar la exposición humana a contaminantes, como por ejemplo, restringiendo el uso del agua subterránea con fines de agua potable. Nivel de Cuantificación Práctica (CVP): es el nivel más bajo de concentración de un componente que puede lo-grarse de manera fiable entre los laboratorios dentro de los límites especificados de precisión y exactitud en con-diciones de laboratorio de rutina. Nivel freático: El nivel freático es una línea imaginaria que marca la parte superior de la zona saturada de agua dentro de la columna del substrato. NPL: Lista Nacional de Prioridades. Una lista desarro-llada por la EPA de lugares expuestos a liberación de sus-tancias peligrosas no controladas en los Estados Unidos que se consideran como prioridad para evaluación reme-dial a largo plazo y respuesta. Nueve Criterios de Evaluación: véase el recuadro de texto en la página 7. Período de Comentarios Públicos: El tiempo permitido para los miembros de una comunidad que puedan resultar afectados para expresar sus opiniones e inquietudes sobre la alternativa remedial preferida de la EPA. Plan de Propuesta: Documento que presenta la alterna-tiva remedial preferida y pide la opinión del público res-pecto a la alternativa de limpieza propuesta. PPR: Las partes potencialmente responsables. MRP: Objetivos Remediales Preliminares. RAOs: Objetivos de acción correctiva. Objetivos de las medidas correctivas que se desarrollan sobre la base de medios contaminados, los contaminantes de interés, los receptores potenciales y escenarios de exposición, la sa-lud humana y la evaluación de riesgo ecológico, y el lo-gro de niveles de reglamentación de limpieza. RI: Investigación para la Recuperación. Un estudio de una instalación que apoya la selección de una solución cuando las sustancias peligrosas han sido eliminadas o sacadas de la misma. El RI define la naturaleza y alcance de la contaminación en la instalación y análisis de riesgo

asociados. Riesgo Cancerígeno: riesgo de cáncer se expresan como un número que refleja la mayor probabilidad de que una persona desarrolle cáncer si está expuesta a productos químicos o sustancias. Por ejemplo, el rango de riesgo aceptable de la EPA para las ubicaciones del Superfondo de residuos peligrosos es de 1 x 10-4 a 1 x 10-6, lo que significa que es una oportunidad adicional de 10 mil (1 x 10-4) a una oportunidad adicional de 1 millón (1 x 10-6) que una persona desarrolle cáncer si está expuesta a un contaminante de el Lugar si no se remedia. Riesgos no Cancerígenos: Los peligros (o riesgos) no cancerígenos se expresan como un cociente que compara el nivel actual de exposición con un nivel aceptable de exposición. Hay un nivel de exposición (la dosis de refe-rencia) por debajo del cual es poco probable, incluso para una población sensible a experimentar, que haya efectos adversos para la salud. El nivel umbral de la EPA para el riesgo de no cancerígenos en las ubicaciones de Super-fondo es de 1.0, lo que significa que si la exposición su-pera el umbral, puede haber una preocupación por los posibles efectos no cancerígenos. ROD Registro de Decisión: Un documento legal que describe la acción de limpieza o remedio seleccionado para una Lugar, la base para la elección de este recurso, y los comentarios públicos sobre el recurso seleccionado con COPCS SLERA: Nivel de evaluación de riesgo ecológico. Una evaluación del riesgo potencial que supone para el medio ambiente si las actividades de recuperación no se realizan en el Lugar. Suelos no saturados: Los suelos que se encuentran por encima de la capa freática. El agua de lluvia o de la su-perficie pasa a través de estos suelos. Estos suelos per-manecen secos. Suelos Saturados: Los suelos que se encuentran debajo del nivel freático. Estos suelos permanecen húmedos. TBC: "a-ser-considerados", consiste en avisos y/o orien-tación no emitidos que fueron desarrollados por la EPA, otras agencias federales, o los estados que pueden ser útiles en el desarrollo de los recursos CERCLA. Unidad Operable (OU): una acción discreta que implica un paso más hacia la solución de los problemas del Lugar de forma abarcadora. Esta porción discreta de una res-

R2-0002657

PLAN PROPUESTO


19

puesta correctiva maneja la migración, o elimina o reduce una descarga, su amenaza, o vía de exposición. La lim-pieza de un Lugar se puede dividir en un número de uni-dades operativas, en función de la complejidad de los problemas asociados con el Lugar.

R2-0002658


Figura 1

Lugar del Mapa

R2-0002659

EPA Región 2 – Agosto 2012 R2-0002660


Figura 2

Ubicación de las cinco áreas de la Investigación Preliminar

R2-0002661

R2-0002662

Figura 3

Ubicación de Plumachos de Contaminación de Agua Subterránea

R2-0002663


Legend - - - Esitmated MCL isocontour

Monitoring Well locations •

Maunabo #1 Public Supply Wells ?

Groundwater Screening Locations

Uncertain lsocontour Boundary A !!""=:=!~~--~====~--~''" 0 106 210 <120 640

Figure 2-1 Plume Map - MCL (IJg/L} lsocontours


R2-0002664

APPENDIXV

Public Notices

-47-

R2-0002665

La Agenda Federal de Protecci6n Amblental Anundit el Plan Ptopuesto y Periodo para Comentarios Pllblicos ·

Lugar de Superfondo Contaminaci6n de Agua Subte"anea del Area de Maunabo Maunabo, Puerto Rico

La Agenda Federal de Protection Ambiental (EPA, por sus siglas en Ingles) en colaboraci6n con Ia Junta de Calidad Ambiental anuncia el Plan Propuesto (Plan) para ellugar conoddo como Contaminaci6n de Agua Subterranea del Area de Maunabo (Lugar). Este Plan describe las altemativas evaluadas para tratar e1 agua subterranea. Ademas, presenta Ia altemativa recomendada para el Lugar y las razones para dicha recomendaci6n. Antes de seleccionar un remedio finat Ia EPA va a considerar comentarios escritOs y verbales recibidos sobre Ia altemativa recomendada en el Plan Propuesto. Todos los comentarios deben ser recibidos en o antes del 7 de septiemhre de 2012. Las respuestas de los comentarios recibidos seran incluidas en el Record de Decision para ellugar. El Record de Decisi(ln es el documento legal que describe el remedio final paralugar. ·

La EPA llevar.! a cabo una reuni6n publica el jueves 23 de agosto de 2012, de 7:00pm a 8:00pm en ellocal anexo a Ia Casa Alcaldfa, Maunabo. PR. Representantes de Ia EPA discutir.!n el Plan y contestaran pregunt~s o comentarios que los partidpantes tengan con relad6n al Plan.

Copias del Plan Propuesto y de toda Ia documentaci6n que apoya el Plan estaran disponibles en los siguientes repositorios de informaci6n:

Biblioteca Municipal Maunabo,PR (787)861-2009 Horario: Lunes-Viernes 8:00AM a 4:30 PM

Junta de Calfdlld Ambiental Prograrna de Emergendas y Superfondo Edifldo de Agenclas Amblentales Cruz A. Matos Urbanizacion San Jose Industrial Pari< 1375 Avenida Ponce de le6n San Juan, PR 00926-2604 (787)767-8181' Ext.3207 Horario:Lunes-Viemes 9:00 AM. a 3:00 PM Pordta

Divis16n de Protecd6n Ambiental del Caribe City View Plaza II- Suite 7000 48 RD, 165 Km.1.2 Guaynabo, PR 0096&-806!1 Fax: (787) 2119-7104 (787) 977-5869 Horario: Lunes· Viemes, 9:00AM a 4:30 PM Pordta

Ofldna Regional de Ia Agenda de Protecci6n Amblental Federal290 Broadway. lath floor New York, New York 10007•1866 (212) 637-4308 Horario:lunes.-Viemes, 9:00AM a 3:30PM Porcita

Para mas informaciOn, favor de comunicarse con et Sr. luis Santos al (787) 977-5824. Comentarios e$Ciitos deben ser enviados a:

Luis E. Santos Gerente de Proyectos

Agencia de Protecd6n Ambiental Federal I Division de Protecci6n Amblental del Caribe City View Plaza II- Suite 7000,48 RD, 165 Km. 1.2, Guaynabo, PR 0096&-8069

FlllCl (7871289-7104/lntVMt: [email protected]

f_).

Cll 0

in .... 2 c:

~ ~ ...... e m < m jll 10 0 m

"' 0 ;::i,

'I

l

R2-0002666

~~~ED Si-41'~~

1 \ \~) ~t.~'"

La Ag ncla Fed I d Proteccl6n Amblental Anuncia el PI n Propuesto y P rlodo para Com ntarlos Publico

Lugar de Superfondo Contamlnac:l6n de Agua Subt rninea del Area de Maunabo

Maun bo, Pu rto Rico LaAgencia Federal de Protec:ci6u .Ambiental (EPA, por sus siglas en ingles) en colaboracion conla.Jw1 de ( · 1 iJ.Amhie•ttah m 1ci el Plan Propuesto (Plan) para cl lu~r conocido como Contaminacion de Agna Snbtemiuea del Areu de l\latmabo (Lugar). Este Plan describe las alternativas evaluad spara tratar el agua subterninea.

Adeuuis, presenta la alt'.E'.rnaLiva recomendacla 1· 1 L•L~· y 111-. rnzonr" p~rn rlkh~ rrt'Olllt>IHhwion 1\nws dt> "~leecionAr un remedio final, la EPA va a rousiderar comenta1ios escritos y verbales recibidos sobre la lllteruativa nx:omeudada en el Plan Propuesto. Todos los comentario~ debe11 ser recibidos en o antes del 7 de

scptiembre de 2012. I..asrespncstas de loscomcntAlios rerihidos sen\n incluiclas en el Record de Dcci .. i6n parael tugar. E!Rccord de Dccisi.6n es el documcnto legal que describe el remedio final para Lugar.

La EPAllevaraacabo una reunion ptiblicael ju.eves, 23 de agosto de 2012, de 7:00pm a8:00 pm en ellocalanexo ala CasaAlcaldia, Maunabo, PR. Rcprcscntantcs de 1a EPA discutinin el Plan y rontestanin pregnntas o comeutarios que los participantes tengan t'OU rehtdou al Plan.

Copia!JdelP P pu )det,-,dal docum 1 ,j,·, "luea • elPianeslarindisponibl enlossiguieotesrepositoriosdeintn ...........

BIBIJOTECAMUNICIPAL JUNTA DE CAUDAD AMBIENTAL- PROGRAMA DIVISION DE PROTECCI6N OFICINA REGIONAL DEL LA DE EMERGENCIAS Y SUPERFO DO AMBIENTAL DEL CARIBE AGENCIA DE PROTECCI6N

Maunabo, PR Edificio de Agendas Amblentales Cruz A. M City View Plaza 11- Suite 700048 RD. 165 AMBIENTAL FEDERAL (787) 861-2009 Urbanizaci6n San~ Industrial Park ,1375 AVN~lda Km. 1.2 Guaynabo, PR 00968-8069 290 Broadway, 18th f '"'

Horario: Lunes - Viemes Ponce de Le6n, San Juan, PR 00926--2604 Fax: {787) 289-7104 {787) 9n-5869 Nr Y '~ Yor\ 10007 18S'i 8:00AM a4:30 1'¥ (787)767-8181, Ext. 3207 Horario: Lunas- Viemes, 9:00AM a 4:30PM (212) 637-4308

Horario: Lunes - V~emes 9:00 AM. a 3:00 PM Por cita Hotario: Lunes.-Viemes, 9:00 ~ a 3:30 Pl ~~ ~~

Para mas informacion, favor de comunicarse con el Sr. T .uis Santos al (787) 977-5824. Comeutn.rios ( <!ritos del • ' dos a: I L •. Santos (Gerente dE" P 0) r-lO~) \<"'(' 1 ".l de Protecci6n Ambiental Fed r -T ,. Ol ~<'16 1 \ 1 ttnl del Cnribe

CitvViewPlazal Sw 8-RD. l65 Km 1.2( P -8069 F~.,.: (787) 289-7104 I ~rn t: santos.lui e.Pn.JZOV

R2-0002667

La Agencia Federal de Protección AmbientalAnuncia el Plan Propuesto y Periodo para Comentarios Públicos

Lugar de Superfondo Contaminación de Agua Subterránea del Área de Maunabo Maunabo, Puerto Rico

La Agencia Federal de Protección Ambiental (EPA, por sus siglas en inglés) en colaboración con la Junta de Calidad Ambiental anuncia el Plan Propuesto (Plan) para el lugar conocido como Contaminación de Agua Subterránea del Área de Maunabo (Lugar). Este Plan describe las alternativas evaluadas para tratar el agua subterránea. Además, presenta la alternativa recomendada para el Lugar y las razones para dicha recomendación. Antes de seleccionar un remedio final, la EPA va a considerar comentarios escritos y verbales recibidos sobre la alternativa recomendada en el Plan Propuesto. Todos los comentarios deben ser recibidos en o antes del 7 de septiembre de 2012. Las respuestas de los comentarios recibidos serán incluidas en el Récord de Decisión para el Lugar. El Récord de Decisión es el documento legal que describe el remedio final para Lugar.

Debido a condiciones climatológicas adversas, La EPA ha reprogramado la reunión pública para el miércoles 29 de agosto de 2012, de 7:00 pm a 8:00 pm en el local anexo a la Casa Alcaldía, Maunabo, P. R. Representantes de la EPA discutirán el Plan y contestarán preguntas o comentarios que los participantes tengan con relación al Plan.

Copias del Plan Propuesto y de toda la documentación que apoya el Plan estarán disponibles en los siguientes repositorios de información:

Biblioteca Municipal Maunabo, PR (787) 861-2009Horario: Lunes - Viernes 8:00 AM a 4:30 PM

Junta de Calidad AmbientalPrograma de Emergencias y SuperfondoEdificio de Agencias Ambientales Cruz A. Matos Urbanización San José Industrial Park 1375 Avenida Ponce de LeónSan Juan, PR 00926-2604(787)767-8181, Ext. 3207Horario: Lunes - Viernes 9:00 AM. a 3:00 PMPor cita

División de Protección Ambiental del CaribeCity View Plaza II- Suite 700048 RD, 165 Km. 1.2Guaynabo, PR 00968-8069Fax: (787) 289-7104 (787) 977-5869Horario: Lunes - Viernes, 9:00 AM a 4:30 PM Por cita

Oficina Regional de la Agencia de Protección Ambiental Federal 290 Broadway, 18th floorNew York, New York 10007-1866(212) 637-4308Horario: Lunes.-Viernes, 9:00 AM a 3:30 PM Por cita

Para más información, favor de comunicarse con el Sr. Luis Santos al (787) 977-5824. Comentarios escritos deben ser enviados a:

Luis E. SantosGerente de Proyectos

Agencia de Protección Ambiental Federal / División de Protección Ambiental del Caribe City View Plaza II- Suite 7000, 48 RD, 165 Km. 1.2, Guaynabo, PR 00968-8069

Fax: (787) 289-7104 / Internet: [email protected]

R2-0002668

APPENDIX VI

Public Meeting Attendance Sheet

-48-

R2-0002669

DE POSICION

~------V~~--~----------Deponente ------------------- '

PRESENTES ~-~~m~RE~C~a~ON~------~~

CA- ~' If

l0&-&46"-

ov

•

\

R2-0002670

APPENDIX VII

Transcript of the Public Meeting and Written Comments

-49-

R2-0002671

FASYO REPORTERS - English and Spanish510 Octavio Marcano Street Urb. RooseveltSan Juan, PR 00918 (787)767-5593 447-8858

AGENCIA DE PROTECCION AMBIENTAL DE LOS ESTADOS UNIDOS

REGION 2

REUNION PUBLICA SOBRE

LUGAR DE SUPERFONDO

CONTAMINACION DE AGUAS SUBTERRANEAS DEL AREA DE MAUNABO;MAUNABO, PUERTO RICO

Fecha: 29 de agosto de 2012, 7:00 P.M.

Lugar: Centro de Usos MúltiplesCasa Alcaldía de MaunaboMaunabo, Puerto Rico

Moderadora: Brenda Reyes, oficial de prensa, EPA

R2-0002672

2


COMPARECENCIAS:

SA. BRENDA REYES, Environmental Protection Agency

SR. LUIS E. SANTOS, Environmental Protection Agency

SR. RAMON TORRES, Environmental Protection Agency

SR. CARLOS O'NEILL, Junta de Calidad Ambiental

SA. NITZA MARRERO FONTAN, Junta de Calidad Ambiental

LCDA. ARLYN GONZALEZ DIAZ, PRIDCO

LCDO. JORGE GARCIA DIAZ, PRIDCO

SR. MICHAEL VALENTINO, CDM Smith

SA. SUSAN SCHOFIELD, CDM Smith

SA. CAROL B. RODRIGUEZ

SR. JOSE LUIS SANCHEZ

****************

R2-0002673

3


PROCEDIMIENTOS

SA. REYES: Mi nombre es Brenda Reyes, yo soy oficial

de prensa de la Agencia Federal de Protección Ambiental.

Estamos aquí hoy para presentarles a ustedes el plan propuesto

para el lugar de superfondo de... el municipio de... de Maunabo

o, como se conoce en inglés, "Maunabo ground water".

Conmigo está el compañero Luis Santos, que es el

gerente de proyecto, Ramón Torres, que es el director interino

de la División de Respuestas y Remediación Ambiental de la

División de Protección Ambiental del Caribe. Tenemos aquí

también a los compañeros de la Junta de Calidad Ambiental, el

señor Carlos O'Neill y a Nitza también, de la Junta de Calidad

Ambiental y los compañeros de CDM, que es el contratista en

este caso.

Durante la noche de hoy, pues, Luis les va a estar

haciendo una breve presentación y estamos, pues, aquí para

contestar preguntas.

SR. SANTOS: Gracias, Brenda.

Bueno, buenas noches, aquí nuestra intención es ir lo

más sencillo posible de traer los hallazgos, los resultados y

las alternativas. Empezamos.

SR. LEON ORTIZ: Con el permiso. Una cuestión de

orden.

SR. SANTOS: Ajá.

(Pausa.)

R2-0002674

4


SR. LEON ORTIZ: Probando. Mi nombre es José Luis León

Ortiz, yo soy de Maunabo, maunabeño de... de nacimiento, vivo

en el barrio de Majagua, pero me crié toda mi vida aquí, en el

sector del pueblo. Soy de oficio maestro, bibliotecario y

promotor cultural... este...

Me parece que hay algún problema por la asistencia

del pueblo de Maunabo, que no ha llegado nadie. Creo que yo soy

el único residente... eh... Y para que no sea esto como una

cuestión de forma ))¿verdad?)), yo solicito de que se haga una

nueva invitación con un mayor énfasis a la ciudadanía para que

participen, porque esto es un tema tan y tan delicado y tan y

tan importante, que me parece que hay una confusión por la

suspensión de... de la fecha y la aproximación de las fiestas

jueyeras y demás, me sorprende sumamente que no esté ni el

periódico La Esquina ni el alcalde ni miembros de la asamblea

ni el centro cultural, que yo los invité para el jueves. El

lunes, yo les dije a ellos que era el jueves,... este... porque

yo pertenezco a ese centro.

Y... este... para que no agotemos esfuerzos

))¿verdad?)) en un proceso pro forma, yo propongo que se haga

un esfuerzo, antes del cierre de... eh... septiembre, que queda

poco tiempo, lo sé, para ver cómo podemos... eh... motivar y

hacer que más personas... eh... participen de toda esta

información tan valiosa, que ustedes tienen bien a darnos.

Ese es mi planteamiento.

R2-0002675

5


SR. SANTOS: Ramón, ¿tú puedes abundar más, qué

podemos hacer con la ---- de él?

SR. TORRES: En el proceso...

(Pausa.)

SR. TORRES: OK. Este es Ramón Torres, de la Agencia

de Protección Ambiental.

Su preocupación, estuve consultando con la Junta de

Calidad Ambiental y lo que vamos a proponer es llevar a cabo

esto pro forma, pero... eh... hacer un "public availability

session". Quiere decir hablar con Luis para la semana que

viene, si usted nos puede apoyar y presentar todas las personas

que estén interesadas para que Luis conteste al... todas las

preguntas que tengan.

Esto se llevó a cabo, para récord, dos veces se

anunció en el periódico, dos veces utilizando El Nuevo Día y

utilizando Esquina. O sea, tratamos de utilizar todos los

medios para que la comunidad se... eh... se informe.

Sí, entendemos, es bajo estatuto, entendemos que,

pues, hay otras actividades fuera de nuestro control, pero yo

entiendo que podemos hacer esto pro forma, llevarlo a cabo,

usted lo pueda observar, todas las preguntas que tiene, con

mucho gusto, le vamos a contestar y, seguido a esto, una sesión

de disponibilidad donde Luis Santos y representantes de la

Junta van a estar disponibles aquí. O tenemos que buscar un

lugar donde podamos y le voy a pedir que nos ayude usted a

R2-0002676

6


traer a las personas que estén interesadas.

Todos los documentos de este proyecto están

disponibles al público aquí, en municipio, ¿no?. Están... la

biblioteca. Le exhorto que busquen todo esto, vean la

documentación que le hemos dados y vengan preparados para

cualquier pregunta o algún "issue" que tengan... eh...

Yo entiendo que, con eso, cumplimos con todos, para

entonces... eh... seguir moviendo este proyecto y poder

resolver la situación que hay aquí, en Maunabo. ¿OK.?

(Pausa.)

SR. LEON ORTIZ: José Luis León, de Maunabo.

El problema es que la no asistencia ))¿verdad?)) del

público de Maunabo a esta actividad, total, menos yo,... eh...

pues, es prueba de que no hubo una comunicación efectiva.

Pero por otro lado, también prueba ))¿verdad?)) la

gravedad en el desarrollo de la conciencia y cómo una situación

tan delicada, pues, en términos de educación comunitaria

ambiental, estamos tan atrás para generar una preocupación y un

mayor envolvimiento comunitario para ayudar a solucionar el

problema... eh...

Sin embargo,... eh... si yo me quedo, sería entonces

pro forma, estaría yo aceptando toda la información que ustedes

me dan, que yo tengo tantas dudas ))¿verdad?)) y tanta cosa en

la mente sobre este particular, porque históricamente, no hemos

sido responsables con el manejo de nuestros desperdicios...

R2-0002677

7


eh...

Nosotros tirábamos la basura en el Mala Pascua, hacia

el mar, por años y años y años. Y esa planta de tratamiento de

agua estuvo ahí botando porquería años y años y años y años...

eh... Entonces,... eh... me parece que, pues, yo, como

ciudadano de este país, pues, tengo... me compromento a ayudar

a procurar que mayor personas participen, estudiantes,

investigadores maunabeños,... eh... la administración pública,

instituciones religiosas, porque Maunabo tiene esa capacidad y

lo ha demostrado en proyectos como el de la... el de... eh...

del humedal, el de los túneles, todos son proyectos con mucho

apoyo comunitario.

SR. TORRES: Unjú.

SR. LEON ORTIZ: Entonces, pues, yo estoy sorprendido

por la ausencia del público.

Entonces,... eh... pues,... eh... no sé.

La solución que usted me brinda es... eh... para mí,

es sinónimo de que los planes, pues, es difícil cambiarlos, por

lo menos, como estaba concebida la actividad en el día de

hoy,...

SR. TORRES: Unjú.

SR. LEON ORTIZ: ...por ese planteamiento que usted

hace que, tanto el señor Santos como cualquier perito... eh...

vinculado, pues, si logramos reunir comunidad, pues, venga a

contestar preguntas y demás, que sea antes del cierre de

R2-0002678

8


septiembre, para que ustedes...

SR. TORRES: Unjú.

SR. LEON ORTIZ: ...se lleven ese influjo... este...

Pero me ponen en una situación bien delicada...

SR. TORRES: No, no, no, pero lo que le estamos...

SR. LEON ORTIZ: Es una inter... interlocución lo que

vamos a tener.

SR. TORRES: Enter... Exacto. Pero... O sea,

obviamente, cumplimos y están... está usted presente y

reconozco que esté aquí. Y esto se va a hacer con una persona

o, si no se hubiese nadie, tenemos aquí representante de... de

PRIDCO. O sea, no... de otra de las compañías. O sea, tenemos

aquí representantes que están pendientes también a eso. Ellos

también pueden comentar. Usted puede comentar. O sea, usted

tiene un respeto, como lo tiene to' el mundo.

SR. LEON ORTIZ: Claro.

SR. TORRES: Y eso... por eso es que no quiero que

usted pierda su tiempo ni... por poder venir aquí y... y con

respeto de los demás que vinieron aquí. Pero por eso estoy

dando la segunda opción, que sería también... O sea, damos

esto, usted ya entiende... se empapa de su... del... de la...

de lo que se está sucediendo y la licenciada presente y

podemos, entonces, tener un diálogo ))¿OK.?)) y ahí tiene una

información suficiente para que la próxima semana... eh... yo

le voy a decir a Luis que, entonces, empiece a trabajar mañana

R2-0002679

9


mismo en buscar un lugar y comunicarse... hablarse con usted

para ponerse de acuerdo y Luis está disponible. Yo,

lamentablemente, no puedo estar disponible,... este... pero...

eh... Brenda va a estar, para entonces facilitar ese diálogo.

Y si hay que presentar nuevamente información, se presenta toda

la información.


SR. TORRES: O sea, no es que vamos a cortarle el

derecho a la comunidad para que se entiende y escuche. Y

volvemos a decir: cumplimos con los requisitos de someterlo,

hemos... estuvimos hablando, lamentablemente, por Isaac,

tuvimos que cancelarlo, pero queremos rápidamente darle a

ustedes el privilegio ))¿no?)) y es su derecho a que... este...

revise, comente, presente sus "concerns", sus preguntas...

preocupaciones y nosotros tenemos nuestra obligación de

contestársela. ¿OK.?

SR. LEON ORTIZ: Eh... bueno...

SA. REYES: Mire, don José, yo le sugiero... Y esto se

me ocurre, porque nos ha pasado también en otros casos, donde,

pues, hay un interés mayor al que generó, pues, una reunión

pública. En su caso, pues, usted nos está comentando que habría

otras personas interesadas.

Nosotros hicimos el debido proceso, se publicó en los

periódicos, se hicieron hojas sueltas, se entregaron esas hojas

sueltas, sabemos que hubo una cancelación, pero nosotros

R2-0002680

10


resolvimos el problema, ¿no?

Se me ocurre que, tal vez ))y lo dialogué aquí

brevemente)) nos podamos reunir en la biblioteca, pedir acceso

a la biblioteca y usted nos traiga un grupo de personas que sí

estén interesadas. Luis y yo estamos allí toda la tarde,

podemos hacer la presentación, tratar de contestar todas las

preguntas... eh... y, pues, un horario que sea conveniente,

porque nosotros, es verdad que tenemos la cues... la... la

situación que está el festival, pero pues, tam... también ))o

sea)) se publicó en los periódicos y, pues, tuvo difusión. Lo

que quiero...

SR. LEON ORTIZ: Sí, sí.

SA. REYES: ...que entienda es que esto tuvo

difusión... eh...

Sin embargo, pues, para complacer su petición, si

usted nos dice, usted llama a Luis, Luis se pone en contacto

conmigo, nosotros estamos en la misma oficina, hablamos por

teléfono... eh... Yo vengo con él el miércoles o el jueves de

la semana entrante.

SR. LEON ORTIZ: Yo soy de... A mí me gustaría...

Fíjese, yo estoy de acuerdo con su... su observación y

considero que la relación entre todos ustedes y nosotros...

eh... debe ser y tiene que ser dinámica y que,... eh... de

acuerdo a la emergencia ))¿verdad?)) o la urgencia que... que...

el problema que estamos tratando,... este... eh...

R2-0002681

11


Sí, lo que pasa es que yo sé que... que tenemos la

fuerza, el talento para apoyar y para coordinar y para hacer

esto... eh... un movimiento envolvente de conocimiento sobre la

situación ambiental...

SR. SANTOS: Unjú.

SR. LEON ORTIZ: ...y nuestra salud... eh... propia,

¿no? Y por eso, estoy sorprendido por la ausencia de personas.

Ahora, el planteamiento que usted hace de varias...

cuando... cuando nosotros lo solicitemos o tengamos las

condiciones, reunirnos... eh... Me parece que eso lo debemos

tener siempre... este...

SA. REYES: Sí, no, eso es siempre.

SR. LEON ORTIZ: ...abiertas estas comunicaciones para

que si tienen que ir a la escuela o tienen... o informar...

eh... o algún grupo de interés que quiera escuchar su

opinión,... eh... se pueda hacer en una forma dinámica. En

realidad, no tienen que ser todos, sino...

SR. TORRES: Sí.

SR. LEON ORTIZ: ...alguien que conozca

técnicamente...

SA. REYES: Sí, nosotros,...

SR. LEON ORTIZ: ...el problema.

SA. REYES: ...como parte de los procesos de

superfondo... Obviamente, el proceso de superfondo... de... de

los casos de superfondo requiere in... eh... con... lo que se

R2-0002682

12


conoce como "community involvement" o que se involucre a la

comunidad... se involucre a la comunidad en todas las partes,

pero comunidad pueden ser ellos, pueden ser un ente

gubernamental, puede ser un ente privado, puede ser personas

que residen...

Claro, yo lo que quiero que entienda es que estamos

dispuestos, el compañero y yo y lo tenemos que hablar con Mike

))¿verdad?)) para que él venga y esté con nosotros, buscamos un

lugar, la biblioteca, usted trae a su gente.

SR. LEON ORTIZ: 'Ta bien.

SA REYES: Nosotros vamos a ir sobre este caso en

específico. Cualquier preocupación ambiental adicional, porque

usted enumeró una serie de preocupaciones de prácticas, de

malos manejos que hubo en el pasado. Hay muchas veces esas

prácticas. No me atañen a mí, como agencia, pero le atañen a...

a la Junta de Calidad Ambiental o le atañen al Departamento de

Salud.

Yo lo que le pido es que, en esa reunión que tengamos

la semana que viene, podamos dialogar sobre esto y contestar

preguntas sobre este caso y, entonces, luego, una vez

terminemos, nos podemos sentar y ver cómo nosotros le podemos

ayudar a canalizar esas otras preocupaciones con las agencias

concernidas. Porque no todo va a caer en manos de la EPA. Eso

se lo anticipo.


R2-0002683

13


SA. REYES: Pero nosotros le podemos ayudar a

canalizarlas. O sea... Y pues, si hay que escribir un... Ramón

tiene que escribir un "email", un memo, se hace...


SA. REYES: ...y se refiere. Porque nos pasa en todos

sitios. Los otros días, Luis y yo tuvimos una reunión en PREPA

Palo Seco y, pues, hubo una serie de preocupaciones que levantó

la comunidad de Cataño Palo Seco... eh... con relación a otra

serie de cosas y yo les di mi número de teléfono y se les dio

unos números de contacto y los ayudamos...


SA. REYES: ...a que ellos canalicen sus

preocupaciones.

Pero realmente, la comunidad se tiene que unir...

SR. LEON ORTIZ: Por eso.... este...

SA. REYES: ...para canalizar esas... esas cosas,

porque no puede ser usted solamente.

SR. LEON ORTIZ: Por eso. Por eso. Y yo sé que... que

hay... O sea, nosotros somos un... un pueblo del tiempo de las

guácaras, antiquísimo, taíno, pero... antiquísimo... este... Y

así lo confirman todos los estudios históricos.

Entonces,... este... además de mucha participación,

sabe, organizado. Entonces, yo estoy sorprendido por completo,

la verdad. Yo no me esperaba esto.

SA. REYES: Pero no fue por falta de tratar.

R2-0002684

14


SR. LEON ORTIZ: Bueno, se hicieron las gestiones,

pero el mensaje no llegó.

SR. TORRES: Sí, no... no... no llegó o ellos no...

escogieron no... no venir. Pero yo entiendo su preocupación y

acuérdese que toda vez tenemos un comentario públic... eh... un

período de comentarios,...

SR. LEON ORTIZ: Sí.

SR. TORRES: ...que si no pudieron y tienen

comentarios por escritos, hágannoslos llegar antes de

septiembre 7, para nosotros, entonces,...


SR. TORRES: ...contestarlos. O sea, que... que la

oportunidad puede ser dinámica, "face to face" o pueden

decidir, si no pueden, hacerlo a través de un... este... un

escrito, ¿no?


SR. TORRES: Pero por eso mismo, yo entiendo que

podemos aprovechar y, si llegan más tarde, lleguen tarde. No

hay problema. Pero yo entiendo que deberíamos de com... de

continuar con... con la charla y la presentación para los que

estén presentes, que entiendan lo que está pasando y, luego,

entonces, como una segunda oportunidad que le demos, el... la

disponibilidad pública, donde... este... tanto Brenda como Luis

y Michael, cuando pueda, si puede,... este... se da y,

entonces, pueden tener ese diálogo...

R2-0002685

15



SR. TORRES: Más directo. Porque un "availability" es

menos formal... eh... y es...

Esto es un requisito formal,...


SR. TORRES: ...por ley...


SR. TORRES: ...este... que hay que hacerlo. Y

entonces, ese "public availability session" yo lo he hecho

muchísimas veces y hasta es más efectivo, porque es el... el

"one on one" y es un período de tiempo... eh... bastante más

largo, ¿no?


SR. TORRES: ¿OK.?


SR. TORRES: Así que yo creo que, si estamos, pues,

podemos continuar, entonces, con los trabajos.

SR. LEON ORTIZ: Bueno, sí,...

SR. TORRES: ¿OK.?

SR. LEON ORTIZ: ...yo me sentaré...

SR. TORRES: OK. Y escuche. Y si tiene...

SR. LEON ORTIZ: ...dedicadamente.

SR. TORRES: Exacto. Pues, siéntase en el honor. Y

muchísimas gracias por estar aquí.

SR. LEON ORTIZ: Gracias.

R2-0002686

16


SR. SANTOS: Gracias, Ramón, gracias, José Luis. Y

pues, retomando eso, el... nosotros estaríamos disponibles

para, en alguna tarde, estar en la... en la biblioteca,

sentarnos allí y atenderte a ti ya todas las personas que tú

puedas convocar, para que nos traigan... Verbales o escrito.

Preferiblemente, de aquí en adelante, preferiríamos que fuera

escrito. Pero podemos estar en cum... en... en...

SR. LEON ORTIZ: Espero que la asamblea tenga una

opinión... eh...

SR. SANTOS: Sí.

SR. LEON ORTIZ: Por eso, le digo que, si aquí no

ponemos interés...

SR. SANTOS: Por eso. Pues, vamos a continuar.

El enfoque de este estudio... los objetivos generales

de este estudio serían definir la naturaleza, alcance y las

fuentes de contaminación de las aguas subterráneas en el

municipio de Maunabo, evaluar el riesgo a la salud humana y

sal... y al medio ambiente, realizar una investigación

remediativa y un estudio de viabilidad.

Para localizarnos, el mapa de Maunabo, tenemos cuatro

pozos de agua potable de donde suple el sesenta porciento de la

comunidad... eh... agua potable para la zona. Pozo número 1, 2,

3 y 4. Todos son de PRASA y hacen la re de suministro de agua

potable para el sesenta y cinco porciento de la población.

SR. LEON ORTIZ: ¿El total? ¿De Maunabo?

R2-0002687

17


SR. SANTOS: De Maunabo. Los barrios... los barrios se

nutren de otras fuentes.

SR. LEON ORTIZ: Ah, cuando usted... Entonces, no; el

total es que... ¿El casco urbano?

SR. SANTOS: El casco urbano.

SR. LEON ORTIZ: El casco urbano, que se puede incluir

Talante, Bordaleza...

SR. SANTOS: Y sus barrios aledaños.

SR. LEON ORTIZ: ¿Las partes llanas?

SR. SANTOS: Exactamente.... este...

(Hablan varias personas a la vez, sin micrófono; el

récord no se entiende.)

SR. SANTOS: Continuamos.

SR. LEON ORTIZ: Yo sigo aportando...

SR. SANTOS: Sí, sí. Compar...

SR. LEON ORTIZ: ...interactúo...

SR. SANTOS: Sí. Pues, yo me detengo, tú hablas, te

identificas y seguimos.

SR. LEON ORTIZ: Exacto.

SR. SANTOS: OK. Y éste es el proceso de superfondo.

Y esto es para que veamos dónde estamos.

Un lugar, en el proceso de superfondo, se descubre el

lugar, se hace un estudio preliminar, ese estudio preliminar

lleva una lista bajo la superfondo, de ahí, se hace una

investigación del lugar, de allí, se llevan datos a un modelo

R2-0002688

18


matemático en el cual se estandariza y, de ahí, va a una lista

nacional de prioridad.

Todo... todo lugar que entra a la lista nacional de

prioridad... eh... pasa por un proceso de "time investigation",

de investigación y de viabilidad, que eso es lo que, realmente,

a lo que vinimos. Y en este punto es que estamos.

SR. LEON ORTIZ: OK.

SR. SANTOS: Antes del estudio remedial y de

viabilidad, que ya fue completado y antes del récord de

decisión. O sea, estamos justamente en la interface entre

estudio de remediación y viabilidad y el récord de decisión.

OK. El trasfondo histórico. El sistema de suministro

de agua potable del casco urbano de Maunabo consta de cuatro

pozos: Urbano, Bordaleza, Calzada y San Pedro. El agua proviene

de estos cuatro pozos y es mezclada y, más o menos, le da...

suple a catorce mil residentes del pueblo de Maunabo y sus

barrios aledaños.

En el 2005, la Autoridad de Acueductos y

Alcantarillados detectó compuestos orgánicos volátiles en el

pozo número 1. El Departamento de Salud ordena que se detenga

el... el... el suministro de agua de ese pozo y,

automáticamente, la Autoridad... eh... instala unos pozos...

unos sistemas de filtración para tratar esa agua. Una vez esa

agua cumple con los estándares federales, el Departamento de

Salud permite que se vuelva a instalar el... el pozo en la red.

R2-0002689

19


SR. LEON ORTIZ: Este... yo tengo una duda ahí.

¿Entonces quiere decir que el pozo 1 y el pozo 4, que son

los... son los más altos contaminantes...

SR. SANTOS: Bueno...

SR. LEON ORTIZ: ...y que la prueba de Salud demostró

que el agua estaba contaminada ))o EPA?)) para no consumo? ¿O

eso es más o menos...?

SR. SANTOS: Lo que ocurre es lo siguiente...

SR. LEON ORTIZ: En el 2000. Ay ¿y en qué año? ¿En el

2000?

VOZ SIN IDENTIFICAR: 2.

VOZ SIN IDENTIFICAR: 2002.

SR. SANTOS: En el 2002. Lo que ocurre es lo

siguiente.

SR. LEON ORTIZ: En el 2002.

SR. SANTOS: PRASA vende agua. El Departamento de

Salud regula esa venta. La... Departamento de Salud se ciñe a

los estándares federales para... de agua potable.


SR. SANTOS: Todo contaminante o toda lista... todo

sustancia que esté listada, que sobrepase los estándares de

calidad de agua federales no cumple con los requisitos para ser

vendida. Por lo tanto, una vez es detectada, el Departamento de

Salud le prohíbe a Acueductos que venda esa agua. Y eso fue lo

que ocurrió allí.

R2-0002690

20


SR. LEON ORTIZ: Que venda esa agua.

SR. SANTOS: Sí, porque Acueductos vende y le cobra a

usted.

SR. LEON ORTIZ: Pero consumo. Esa es de consumo.

SR. SANTOS: Bueno, venta, venta. Acueductos vende y

el pueblo consume.

SR. LEON ORTIZ: ¿El Departamento de Salud...

SR. SANTOS: Regula esa venta.

SR. LEON ORTIZ: ...no interviene en la... en la...?

Entonces... O sea, pero también intervienen en la regulación

para el consumo, ¿no?

SR. SANTOS: El... el...

SR. LEON ORTIZ: Y además de la cuestión de la venta

que pueda estar ahí...

SR. SANTOS: Bueno, es que es una venta, es una venta.

Ellos venden agua. Y esa agua tiene que cumplir con unos

estándares.

SR. LEON ORTIZ: OK.

SR. SANTOS: Y la entidad que tiene la jurisdicción

para velar que cumpla con esos estándares es el Departamento de

Salud.

SR. LEON ORTIZ: Entre otras.

SR. SANTOS: El Departamento de Salud es el que dice,

el que monitorea constantemente, mensualmente Acueductos, para

que esa agua que está vendiendo cumpla con los estándares

R2-0002691

21


federales.

SR. LEON ORTIZ: Y en el 2000 o el 2000...

SR. SANTOS: Eso fue en el 2002, se encon...

SR. LEON ORTIZ: ¿En el 2002?

SR. SANTOS: ...se encontró que el pozo número 1 no

cumplía con esos estándares.

SR. LEON ORTIZ: ¿El 1?

SR. SANTOS: El 1.

SR. LEON ORTIZ: ¿Y esa fue la alarma que...?

SR. SANTOS: Esa fue la alarma. Se le ordena que

detenga la venta y ellos optan por hacer un tratamiento y se le

permite, con el tratamiento, que vuelvan a seguir vendiendo.

Porque el tratamiento reducía los... este... las... las

sustancias.

SR. LEON ORTIZ: ¿Y fue efectivo el tratamiento?

SR. SANTOS: Sí, fue efectivo. Por eso fue que ellos

le permitieron seguir.

SR. LEON ORTIZ: ¿Y le permitieron seguir?

SR. SANTOS: Y hasta la fecha, están vendiendo.

SR. LEON ORTIZ: ¿Y el Departamento de Salud también

siguió permitiendo de que se vendiera esa agua?

SR. SANTOS: Sí, sí.

SR. LEON ORTIZ: Porque ya había... El pozo 1...

SR. SANTOS: El pozo...

SR. LEON ORTIZ: ...había bajado...

R2-0002692

22


SR. SANTOS: ...1, con el tra...

SR. LEON ORTIZ: ...los estándares de...

SR. SANTOS: ...con el tratamiento.

SR. LEON ORTIZ: ...contaminci... ¿Con el tratamiento?

SR. SANTOS: Con el tratamiento le llegaban los

valores a los estándares.

SR. LEON ORTIZ: ¿En ese pozo?

SR. SANTOS: En ese pozo. Los otros pozos, no había

problema

SR. LEON ORTIZ: ¿Todavía no había problema?

SR. SANTOS: OK. 2005. Se realiza una inspección del

lugar, ya estamos, ya, en el proceso de superfondo, donde el

Maunabo 1 y el Maunabo 2 tienen niveles por debajo de los

estándares. El "MCL" son los estándares de calidad de agua

federales.

En el 2005, se realiza una investigación para

identificar las fuentes de esta contaminación y, hasta ese

momento, no pudimos detectar quién era el causante de esa

contaminación.

En el 2006, el lugar entra a la lista nacional de

prioridad. Básicamente, lo que estoy repasando es la tabla que

di... eh... anteriormente; el proceso de superfondo.

SR. LEON ORTIZ: ¿En el 2006 entra a dónde? ¿NPL?

SR. SANTOS: Entra a la lista nacional de prioridad...

SR. LEON ORTIZ: ¿Eso es...

R2-0002693

23


SR. SANTOS: ...federal.

SR. LEON ORTIZ: ...del gobierno total?

SR. SANTOS: Federal.

SR. LEON ORTIZ: Federal... eh... OK.

O sea, ¿que el caso fue considerado de emergencia y

se atendió?

SR. SANTOS: Sí. Fue como hablamos aquí, como hablamos

aquí. El... el lugar es... es detectado al... en el momento en

que el Departamento de Salud prohíbe la venta de esa agua,...

SR. LEON ORTIZ: OK.

SR. SANTOS: ...porque hay una violación de los

estándares. Se hace un estudio preliminar. Este es el que es el

del 2004, se hace un estudio del lugar ))2005)) y todo esto

lleva a la lista nacional de prioridad en el 2006.

SR. LEON ORTIZ: OK.

SR. SANTOS: Y cumple con los requisitos de la EPA. Ya

esto es la EPA.

SR. LEON ORTIZ: Muy bien.

SR. SANTOS: OK. Seguimos.

En el... del 2010 al 2012, la EPA... Y estamos en

este proceso.

SR. LEON ORTIZ: ¿Aquí?

SR. SANTOS: Estamos aquí.

SR. LEON ORTIZ: OK.

SR. SANTOS: Ya éste es éste...

R2-0002694

24


SR. LEON ORTIZ: OK.

SR. SANTOS: ...y estamos aquí, en este lugar...

SR. LEON ORTIZ: Se toma acción...

SR. SANTOS: En este lugar. Toma acción y, durante el

2010 al 2012, la EPA inició y completó la investigación

remedial del lugar.

En el 2012, EPA inició y completó los... los... los

siguientes documentos: el estudio de riesgo a la salud, el

estudio de riesgo ecológico y el estudio de viabilidad. Esos

estudios están en la mesa.

SR. LEON ORTIZ: Sí. Tengo uno allí.

SR. SANTOS: Y están en el depositorio, en la

biblioteca de la Alcaldía.

SR. LEON ORTIZ: Esos no los vi. Estaban... No, no,

eso no... Bueno,...

SR. SANTOS: Están.

SR. LEON ORTIZ: ...no puedo decir si no estaban.

SR. SANTOS: Pero dé la vuelta y, si no están,...

SR. LEON ORTIZ: Y yo...

SR. SANTOS: ...están, pero si no...

SR. LEON ORTIZ: ¿Pero están... este...? Yo...

SR. SANTOS: Sí.

SR. LEON ORTIZ: Pues, cómo no.

SR. SANTOS: O sea, todo este estudio, del 2010 al

2012, concluye en que se completan los estudios de riesgo...

R2-0002695

25



SR. SANTOS: ...y se completan los estudios de riesgo

ecológico y riesgo humano. Y se hace un estudio de viabilidad

con los resultados.

SR. LEON ORTIZ: OK.

SR. SANTOS: OK.

SR. LEON ORTIZ: ¿Eso fue este año, en el 2012?

SR. SANTOS: 2012. Se completó. Empezó en el 2010 y se

completa en el 12.

SR. LEON ORTIZ: Ah.

SR. SANTOS: O sea, que esto es reciente.


SR. SANTOS: OK. Aquí tenemos las tres áreas que

fueron estudiadas. Se hizo un estudio preliminar que coge todo

el pueblo; todas las áreas que identificamos que podían ser las

causantes...

SR. LEON ORTIZ: ¿De la contaminación?

SR. SANTOS: ...de la contaminación y llegamos que, de

todas esas cinco áreas que nosotros estudiamos, nos quedamos

con tres áreas. Y ahí fue donde hincamos los pozos. Se hincaron

dieciséis pozos, mas los cuatro pozos de la... de Acueductos,

son veinte. Y ésos son la red de muestreo...


SR. SANTOS: ...que da base a los resultados.


R2-0002696

26


SR. SANTOS: OK. Las actividades de campo constaron de

muestras de agua subterrá... muestras de... de... las

preliminares, que fue lo que yo le mencioné, se hicieron

muestras de suelo, se hicieron muestras y se instalaron pozos,

se hicieron muestras de agua subterránea y se hicieron muestras

de agua superficial y sedimento en el Río Maunabo.

O sea, que nosotros comprendimos todo lo... todo,

todo, todo, todo el ambiente. Preliminar, hay suelo, agua

subterránea, agua superficial y sedimento en el río.

SR. LEON ORTIZ: En el área específica que ustedes

señalaron o, por ejemplo, en el río, ¿hasta la...

SR. SANTOS: En el río, era...

SR. LEON ORTIZ: ...hasta la boca?

SR. SANTOS: Bueno, en el río... Hasta la boca. Desde

antes del pueblo...

SR. LEON ORTIZ: ¿En el puente...?

SR. SANTOS: Desde antes del pueblo, has... pasando

por todo el sur, hasta la boca.


SR. SANTOS: OK. No se encontraron contaminantes

específicos en el lugar para aguas superficiales en el río. O

sea, el río, no se encontró contaminación. No se encontraron

contaminantes específicos en el lugar para los suelos. En el

suelo, no se encontró contaminación.

Entonces, ¿qué se encontró? Tres penachos de

R2-0002697

27


"dicloretano", tetracloroetileno y "dicloretileno". Esos tres

penachos fueron los que se encontraron en las aguas

subterráneas. O sea, que agua superficial, sedimento y suelo,

no hay problema. El problema radicada en el agua subterránea.

Y se encontraron tres penachos.

SR. LEON ORTIZ: OK.

SR. SANTOS: ¿De dónde pueden venir estos penachos?

¿Quién... quiénes ser las fuentes? Pues mira, podrían ser los

"dry cleaners", podía ser "degreaser"; "degreaser", pues, algún

tipo de negocio formal o informal en la zona, que se dedicara

a... a utilizar estas sustancias para limpieza y manejo de...

de un proceso. Podía ser doméstico...

SR. LEON ORTIZ: ¿Motores y cosas?

SR. SANTOS: Podía ser doméstico, podría ser

industrial...

SR. LEON ORTIZ: Como el Batey Columbia, que toda la

historia estuvo allí una central dedicada a la maquinaria

particularmente,...

SR. SANTOS: Exactamente.

SR. LEON ORTIZ: ...que lo que hacían era... eh...

trabajar con "troces" y tirar los aceites a... a...

SR. SANTOS: O sea,...

SR. LEON ORTIZ: ...a tierra.

SR. SANTOS: ...que estos productos que encontramos,

el origen podría ser de los "dry cleaner" o "degreaser".

R2-0002698

28


SR. LEON ORTIZ: OK.

SR. SANTOS: OK. Aquí, ésta ilustra los tres áreas

trabajadas. Y los tres penachos. Aquí tenemos uno, otro... las

tres estrellas. Donde están las estrellas es donde están los

penachos.

SR. LEON ORTIZ: OK.

SR. SANTOS: Penacho es porque es debajo del agua.

Debajo del suelo. Plumacho sería aire que está corriendo en la

superficie.

OK. Desde el punto de vista de riesgo humano, todos

los parámetros en el suelo están dentro del rango establecido

por la EPA. O sea, que lo que... Volvemos atrás. En suelo, no

hay problema de contaminación alguno. Se muestreó en todas las

áreas de "screening", que fue prácticamente todo el pueblo y

ninguno de los suelos encontramos que había problema de riesgo

humano.

SR. LEON ORTIZ: O sea, que está apto pa' la... para

la agricultura,...

SR. SANTOS: El terreno.

SR. LEON ORTIZ: ...desarrollo... eh...

SR. SANTOS: Sí, señor.

SR. LEON ORTIZ: ...y demás. ¿Está apto?


SR. LEON ORTIZ: Ganadería, plátanos...


R2-0002699

29


SR. LEON ORTIZ: OK.

SR. SANTOS: Aquí estamos hablando de riesgo ecológico

a la salud. Los potenciales sustancias químicas de preocupación

planteada es en el... no plantean riesgo significativo a la

EPA... a la... al... por la EPA a la... al ambiente. O sea,

primero, hablábamos humano. Lo que estoy aquí llevando es el

ambiente. Este es el riesgo a un... al medioambiente. Y ese

riesgo al medioambiente no tiene ningún... El medioambiente no

está en riesgo. Lo que estamos hablando es si es plantas,

animales, no están en riesgo.

SR. LEON ORTIZ: ¿Ni la cadena alimentaria?

SR. SANTOS: Ni la cadena alimentaria.

Cuáles fueron las alternativas para bregar con los

cuatro... con los tres penachos.

La alternativa número 1 sería no acción. Y es una

base. Es un be... Se utiliza siempre como base para verifi...

para... como base de comparación.

Alternativa número 2 consta de un muestreo de

atenuación. Es dejar que la naturaleza modifique... eh... los

contaminantes y nosotros dedicarnos a monitorearlos, a ver cómo

va el proceso de... de degradación.

La alternativa número 3 haría la monitoría, pero

inyectaría también aire, de tal manera que acelere la... el...

la descomposición de estas sustancias y bajen los niveles en el

agua.

R2-0002700

30


SR. LEON ORTIZ: Y ese aire, cuando... ¿Hacia dónde

saldría?

SR. SANTOS: Ese aire va al... al terreno. Inyectado

al terreno.

SR. LEON ORTIZ: O sea, ¿sale de la subterráneo a la

superficie?

SR. SANTOS: Se inye... se inyecta directamente al

suelo, promoviendo que el contaminante que está allí, en esa

agua, se acelere y haya degradación. O sea, que...

SR. LEON ORTIZ: ¿Degradación como natural, con el...

SR. SANTOS: Natural.

SR. LEON ORTIZ: ...con... con el... con la...

SR. SANTOS: Estamos...

SR. LEON ORTIZ: ...adquisición de aire?

SR. SANTOS: ...estamos... Lo que haría la naturaleza,

lo estamos acelerando.


SR. SANTOS: La naturaleza, si no le haces nada, la

misma naturaleza lo va a degradar.


SR. SANTOS: Con este aire, promovemos que se degrade

en menos tiempo.

SR. LEON ORTIZ: Muy bien. Entonces, el aire que sale,

¿está contaminado o ya está atenuado, antes de expulsarlo a la

atmósfera?

R2-0002701

31


VOZ SIN IDENTIFICAR: Está atenuado ---- (habla sin

micrófono; no se escucha).

Entendemos que ya está atenuado, porque tenemos ----

partes por millón y, cuando salga, va a salir por ----, de una

forma que no se puede ni detectar.

SR. LEON ORTIZ: ¿Que no se puede detectar? O sea, que

problemas en la piel,... eh... por contacto directo,

respiración...

SR. O'NEILL: Carlos O'Neill, de la Junt'e Calidad

Ambiental. El aire que va a salir... este... Estamos hablando

con unos rangos de partes por "billón" en el agua, que son bien

pequeños. Son unas cantidades, concentraciones bien pequeñas.

Una vez... Si algún... eh... de estos gases escapa con el

aire,... eh... son cantidades tan pequeñas que no se pueden

detectar en aire y no tienen ningún tipo de efecto en la salud

o en el... el... el ecosistema.

SR. LEON ORTIZ: Ahora entendí esa... Oiga, porque es

que, entonces, al poner... eh... ese sistema a... a... le lleva

aire a las aguas subterráneas...

SR. SANTOS: Aguas subterráneas...

SR. LEON ORTIZ: ...y, entonces, ahí comienza un

proceso de aceleración, como si fuera la descomposición natural

de esos organismos.

SR. SANTOS: De esas sustancias.

SR. LEON ORTIZ: De esas sustancias. Que no es para

R2-0002702

32


sacar... Porque yo creía que era...

SR. SANTOS: No, no es extraer.

SR. LEON ORTIZ: ...eh... sacarlo hacia afuera.

SR. SANTOS: No, no, no, no. Es inyectar aire al agua

subterránea...

SR. LEON ORTIZ: Ahora entiendo.

SR. SANTOS: ...y eso promueve la degradación de esas

sustancias a niveles aceptables.

SR. LEON ORTIZ: Muy bien. Entendí.

SR. SANTOS: En el pozo número 4, sería

biorremediación en el lugar. Ya usted estarían utilizando

sustancias químicas inyectadas en el subsuelo, en el agua

subterránea, para acelerar la degradación de estos compuestos

y que cuan... y que no... y bajar los niveles y que sean

aceptables, dentro de los estándares de calidad de agua.

La alternativa número 3 fue la que escogimos,...


SR. SANTOS: ...que fue la... la que te expliqué. Era

inyectar y monitorear.

Y básicamente, esto sería un... un... una gráfica de

cómo... Aquí, tú ves que se está inyectando, por estos tubos,

al agua subterránea, promoviendo que esta agua subterránea

tenga una degradación y que esas... y que esos... y que esos

compuestos, que ya detectamos, bajen en sus niveles.

SR. LEON ORTIZ: Entiendo. ¿Tienen una idea bastante

R2-0002703

33


clara de hasta dónde es la contaminación? ¿Hasta qué tiempo,

más o menos, se llevaría esa descontaminación? Y una cosa que

leí, que me preocupó, era que hablaban de una ronda pa... eh...

que ustedes pensaban que, en una ronda... no sé el término que

usaron para describir qué... de qué era la ronda... eh... creo

que es de eso mismo, de aereación,... eh... podían ya, el

problema, más o menos... eh... determinarlo.

¿Pero qué... qué... qué implica una ronda... eh... de

esos sistemas,...

SR. SANTOS: Bueno...

SR. LEON ORTIZ: ...en... en... a tono con... eh...

la... la... los análisis que ustedes han hecho de la cantidad

de agua subterránea contaminada que existe?

SR. SANTOS: OK. Cuánto tiempo tenemos que estar

inyectando aire lo va a determinar la monitoría.

SR. LEON ORTIZ: OK.

SR. SANTOS: A medida que vayamos progresando el

número de días aplicando aire, vamos segui... seguido con la

monitoría y esa monitoría nos va a decir cuán efectivo estamos

siendo y cuándo debemos ya entender que hemos ya remediado la

situación. Por eso, la monitoría va... va ligada a la

inyección. Una...

SR. LEON ORTIZ: ¿A la ronda?

SR. SANTOS: A la ron...

SR. LEON ORTIZ: ¿A la ronda?

R2-0002704

34


SR. SANTOS: A la ronda. Una... una va ligada a la

otra. Yo no puedo hacer inyección y olvidarme de monitorear,

porque no estoy detectando qué es lo que es.


SR. SANTOS: O sea, yo tengo que ver cuánto tiempo

llevo en esa ronda inyectando, cuáles fueron los resultados;

qué niveles tengo y cuánto... qué porciento yo estoy... eh...

degradando.

SR. LEON ORTIZ: ¿Pero ustedes están partiendo de la

premisa de que... eh... del evento de contaminación ya se

controló? ¿Que ya no existe más?

SR. SANTOS: Bueno, estamos partiendo de la premisa

que, al... a la fecha de hoy, no tenemos detectado una fuente

de contaminación.

SR. LEON ORTIZ: ¿A la fecha de hoy?

SR. SANTOS: La... No hay fuente. Ha una contaminación

existente. De dónde viene, de dónde proviene, no lo tenemos. Y

si se está inyectando actualmente, no, porque tendríamos que,

a medida... en... en... en las dos rondas que se hicieron, en

los dos estadíos de monitoreo que se hicieron, básicamente,

reprodujeron. Se hizo seis meses entre una y otra, hubo

reproducción. Lo que... lo que nos indica que no están yendo

inyección...

SR. LEON ORTIZ: ¿Lo que implica que...

SR. SANTOS: ...de contaminantes.

R2-0002705

35


SR. LEON ORTIZ: ...que no habían más...

SR. SANTOS: No hay fuente. No hay...

SR. LEON ORTIZ: No hay fuente.

SR. SANTOS: Ahora mismo, no hay fuente.

SR. LEON ORTIZ: Bueno, entonces, quería de...

SR. SANTOS: La fuente estuvo y... y... inyectó...

SR. LEON ORTIZ: Y...

SR. SANTOS: ...y tenemos el... el... el efecto. Pero

quién lo causó es lo que todavía no hemos... eh... logrado.

SR. LEON ORTIZ: Bueno, nosotros hemos... eh... Por lo

menos, yo he analizado la situación y me parece que fue el mal

manejo de la planta de tratamiento de las aguas negras de la

Autoridad de Acueductos y Alcantarillados y que, tan pronto

repararon ese monstruo que había ahí, pues,... eh... la cosa,

pues, se mejoró, ¿no? Porque... eh... hicieron una inyección

ahí de unos cuantos... eh... miles de dólares. O millones.

Entonces, pues, de hecho, eso implica, entonces, quiere decir

que se paralizó la fuente de contaminación, por las mejoras que

le hicieron a la planta de tratamiento.

SR. SANTOS: Hay que partir de la premisa de que esa

plant'e tratamiento es una plant'e tratamiento de aguas usadas.

No es industrial.

SR. LEON ORTIZ: De aguas usadas.

SR. SANTOS: Por lo tanto. Y los re... los

contaminantes que estamos detectando son industriales.

R2-0002706

36


SR. LEON ORTIZ: Vaya. Mira p'allá.

SR. SANTOS: Unos son... Porque lo que... lo que está

entrando a la planta de aguas... de aguas negras, de

tratamiento de Acueductos es aguas usadas. Aguas que vienen de

los... se... las servidumbres públicas.

SR. LEON ORTIZ: Pero el resultado del tratamiento de

esas aguas, inefectivo, lanzado por ahí p'abajo... eh... a la

superficie y a las aguas... eh... O sea, los químicos que ellos

estaban utilizando para tratar de corregir el... grave

situación...

SR. SANTOS: Este químico en particular,...

SR. LEON ORTIZ: No... no...

SR. SANTOS: ...que es detectado...

SR. LEON ORTIZ: No se registra...

SR. SANTOS: ...no tiene... no tiene... no tiene

conexión.

SR. LEON ORTIZ: Porque la otra sospecha que nosotros

tenemos es que, cuando se estableció un vertedero en el Barrio

El Tumba'o,...

SR. SANTOS: Unjú.

SR. LEON ORTIZ: ...que queda entre ese puente que

está ahí, en El Tranque y el otro puente, que queda... eh...

camino a Palo Seco, establecieron un vertedero. Y fue para la

época donde la Union Carbide había sido demandada y tenía que

cerrar en Yabucoa y demás y... eh... la experiencia que tenemos

R2-0002707

37


es que ahí se tiraron tóxicos de allí, aunque se le puso una

malla y qué sé yo y que nos parece, también, que algunos de los

elementos contaminantes provenían de la base Roosevelt Roads.

Pero no tenemos información que nos demuestre ese

dato, porque pregunté y parece que no había control, en esa

época, de quiénes eran los que llevaban allí materiales y

depositaban.

SR. SANTOS: Este es el propósito de estos

conversatorios. Porque ahora mismo, ya lo que está allí y está

allí y nosotros venimos a decir cómo lo vamos a remediar.

SR. LEON ORTIZ: Pero ustedes no estudiaron esa área.

SR. SANTOS: Pero lo que vamos a... lo que vamos a ver

es quiénes fueron las fuentes y nos va a ayudar a detectar.

O sea, toda información que tenga la comunidad, que

nos ayude a determinar o detectar qué posibles compañías, qué

posibles entes fueron los causantes, nos va a ayudar a poder

lidiar con esta... con... con el proceso de... de...

SR. LEON ORTIZ: Básicamente,...

SR. SANTOS: ...de remediación.

SR. LEON ORTIZ: ...ahí... eh... trajeron tóxicos de

Yabucoa, de la Union Carbide...

SR. SANTOS: Esa información...

SR. LEON ORTIZ: ...y de la Sun Oil.

SR. SANTOS: ...es excelente.

SR. LEON ORTIZ: Y de la Sun Oil.

R2-0002708

38


SR. SANTOS: Esa información es excelente. Y toda

información que usted tenga al respecto, tráigala. Porque

nosotros lo analizamos y nos va a ayudar a detectar quiénes o

quiénes fueron los causantes de esta contaminación.

SR. LEON ORTIZ: Bueno, habría que hacer una

investigación para... eh...

SR. SANTOS: Nosotros estamos dispuestos a hacerla.

SR. LEON ORTIZ: ...para... este... ver... eh... los

archivos del manejo de aquel vertedero,...

SR. SANTOS: Unjú.

SR. LEON ORTIZ: ...si se llevó algún registro...

eh... de esos... de... de esa basura que tiraron ahí.

O sea, yo desconozco si eso existe. A... hasta ahí...

Yo pregunté, me comentaron que eso, los vecinos y demás, qué

había sucedido y... este... hasta ahí yo puedo dar la

información...

SR. SANTOS: Este estudio tiene dos funciones

principales. Uno es evaluar la concentración y la magnitud de

la contaminación en el lugar y otra es detectar quiénes fueron

los causantes de la contaminación.

SR. LEON ORTIZ: Pues... eh...

SR. SANTOS: Al momento, hemos sido exitosos

determinando qué hay, en qué concentraciones y cómo lo vamos a

resolver.


R2-0002709

39


SR. SANTOS: Pero no hemos sido exitosos en buscar

quién fue el causante.

SR. LEON ORTIZ: Quién fue.

SR. SANTOS: Y toda información que tenga la comunidad

nos va a servir de una ayuda extraordinaria.

SR. LEON ORTIZ: Porque, para récord, quiero señalar

que Maunabo tiene un desempleo del sesenta y cuatro porciento,

que no hay fábricas. A penas,... este... una o dos cosas que

llegan, unos meses y... o dos años y se van,... este... bajo

unas condiciones... este... de pocos estímulos económicos y de

una belleza... eh... significativa, el pueblo y su contorno.

SR. SANTOS: Continuamos.

Pues básicamente, ésta es la... la presentación.

Hemos tratado de hacerla lo más sencilla posible. En el

depositorio están todos los documentos que hemos utilizado para

llegar a esta... a esta... conclusiones.

Aquí fue una colaboración de la Jun... de... Esto es

un proyecto que está liderado por la... por la EPA... eh... La

Junta de Calidad Ambiental es nuestro compañero en el trabajo

y el municipio de Maunabo nos ayudó un montón con los accesos

y con la...


SR. SANTOS: ...los trabajos.

SR. LEON ORTIZ: Claro. Así es.

(Pausa.)

R2-0002710

40


SR. LEON ORTIZ: Muchas gracias,...

SR. SANTOS: José Luis,...

SR. LEON ORTIZ: ...señor Santos.

SR. SANTOS: ...aquí estoy a tus órdenes.

SR. LEON ORTIZ: Lo sé.

SR. SANTOS: Ya, desde el princi... desde que

hablamos... dialogamos en un principio,... eh... yo me

comprometo a que, ya sea el lunes, el martes, en la tarde,

miércoles o jueves, que decidamos, estar presente en la

biblioteca, que es donde está el depositorio y recoger

preguntas, dudas y todo el docu... toda la información que

venga.

Ya, en este momento, nos gustaría que lo que trajeran

fuera escrito.

SR. LEON ORTIZ: ¿Escrito?

SR. SANTOS: Sí, escrito, porque el foro para traerlo

verbal era éste.


SR. SANTOS: Y realmente, lamentablemente, pues, no...


SR. SANTOS: ...tuvimos la asistencia que esperábamos.

SR. LEON ORTIZ: Sí, yo esperaba posición de la

Asamblea, posición de Centro Cultural, posición de las i... Yo

esperaba algo más...

SR. SANTOS: Pero tú has sido bien, bien... este...

R2-0002711

41


Nos has ayudado un montón, porque nos has encaminado por unos

caminos que... que, una vez nosotros estemos analizando unas...

las... las... este proceso de... de respuesta a la actividad,

tenemos que tomar en consideración to' lo que tú has dicho.

SR. LEON ORTIZ: Gracias... este... Pero imagínese la

importancia para nosotros de sus intervenciones para resolver

este problema, que puede ser más grave aun si no se toman las

medidas remediativas,...

SR. SANTOS: Ahora mismo...

SR. LEON ORTIZ: ...salubristas y... Por ejemplo, con

los estudiantes. Una comunidad, una población, hay una escuela,

hay un hospital, hay un cuartel de la policía, está toda el

área... este... sur del pueblo,... eh... Bordaleza, la parte

este. O sea, hay toda una comunidad... Los parques... eh... yo

que soy fe... que estoy... cuento la boca... eh... como el

lugar de preferencia de esparción, pues,... eh... imagínese la

importancia que esto tiene para nosotros... este... Y le

agradecemos sobremanera... eh... que la agencia se haya

preocupado y que continúe investigando...

SR. SANTOS: Sí.

SR. LEON ORTIZ: ...y estamos en la disposición de

colaborar en todo lo que nos podamos.

Pero por ejemplo, mire, el lunes es... regularmente,

nos reunimos en el Centro Cultural de Maunabo. Allá, analizamos

y demás, que es nuestro foro público y demás. El Festival

R2-0002712

42


Jueyero termina el primero de septiembre. En esos cuatro

días,... eh... yo podría... A menos que si ustedes ponen hojas

sueltas ))¿verdad?)) en el festival o ponen algún... algunos

mensajes disponibles para la comunidad, que se puede

aprovechar. E inclusive, utilizar... eh... la tarima. Nosotros

tenemos el sábado por la tarde, que se la podíamos brindar,...

eh... antes de un espectáculo que tenemos de bomba y plena,

para que se exponga a la comunidad la preocupación y...

Porque la gente está alarmada y yo creo que está

asustada también, pero todavía no ha entendido el problema y

las soluciones que... Creo yo. A menos que no sea... eh... yo

el que estoy perdido y to' el mundo sabe de que la cosa está

bajo control y que no debo tener tanta preocupación... eh...

Pues, yo le doy las gracias, señor Santos, por esta

información. Las dudas que yo tenía, básicamente, yo se las

hice.

La otra pregunta que tengo es si no hace falta

medidas salubristas... eh... de emergencia... eh... para

orientar a la comunidad... eh... sobre el agua... eh...

potable, el filtro,... eh... si es necesario pasarla por

algunos procesos, si es confiable y demás,... eh... que

podamos, en estas... Porque esto se llena, orientar y eliminar

la preocupación ciudadana de que hay una crisis... eh... de

emergencia en los pozos subterráneos de Maunabo.

SR. SANTOS: En este momento, yo no utilizaría esa

R2-0002713

43


palabra, crisis de emergencia. Yo lo que te diría es que los

pozos... los cuatro pozos que utiliza la Autoridad para

servirle agua al pueblo están aptos para ser consumidos.

SR. LEON ORTIZ: Eso es bien importante. Eso es bien

importante...

SR. SANTOS: Yo diría que está apto,...

SR. LEON ORTIZ: ...que el pueblo...

SR. SANTOS: ...porque...

SR. LEON ORTIZ: ...lo sepa, lo conozca...

SR. SANTOS: ...las sustancias que encontramos no han

llegado a los pozos. Por lo tanto, esas sustancias están bien

alejadas y las propu... y las... el remedio que estamos

proponiendo es para disipar este contaminación para que nunca

llegue al pozo de agua potable.

SR. LEON ORTIZ: Muy bien. Y...

SR. SANTOS: Actualmente, no hay problema, en base a

los resultados de nuestros análisis.

SR. LEON ORTIZ: Pero yo, según leí, hablaba de que

hicieron unas pruebas en algunos... eh... plumas pública...

eh... plumas de las casas y que también habían unos márgenes

preocupantes de contaminación, no sé en qué área fue... este...

Me preocupa si eso se sigue haciendo.

SR. SANTOS: No, no,...

SR. LEON ORTIZ: Si eso no es así...

SR. SANTOS: ...en el estudio de nosotros...

R2-0002714

44


SR. LEON ORTIZ: ¿No?

SR. SANTOS: No.

SR. LEON ORTIZ: ¿No? Ah, pues...

SR. SANTOS: Nosotros estudiamos el... el pozo y la

pluma del pozo. Cogimos muestras en el pozo de... de... de

PRASA y en la pluma adyacente al pozo, antes y después del

tratamiento, en el caso que hubiera tratamiento. Y en ambos...

eh... muestras dio apto para ser consumido.

SR. LEON ORTIZ: Para consumo. Ay, qué alegría.

SR. SANTOS: O sea, que está siendo efectivo.

SR. LEON ORTIZ: Qué alegría.

Entonces, ¿eso sería así, básicamente...

SR. SANTOS: Eso no quiere decir...

SR. LEON ORTIZ: ...permanente?

SR. SANTOS: ...que pueda tener un sabor específico,

porque cada zona de la isla tienen sabores diferentes.

SR. LEON ORTIZ: Sí, sí, sí, sí, sí, sí. Aquí decimos

que si uno toma agua de allá, de La Pica, se queda en el

pueblo. Cada región tiene la...

SR. SANTOS: Tiene un sabor...

SR. LEON ORTIZ: Esa gestión...

SR. SANTOS: ...diferente.

SR. LEON ORTIZ: ...particular...

SR. SANTOS: Eso no entra dentro del ajuste...

SR. LEON ORTIZ: Un cariño al agua, al río, a... Una

R2-0002715

45


bendición ))¿verdad?)) que el agua es tan necesaria.

SR. SANTOS: Unjú.

SR. LEON ORTIZ: Entonces, su cuerpo y cómo debemos

protegerlo.

SR. SANTOS: Unjú.

SR. LEON ORTIZ: Pues fíjese, a mí me parece que...

Qué bueno que están las aguas aptas; qué bueno que hay un plan

de remediación... este... Me parece que, entonces, lo que hay

es una preocupación social, que se puede aclarar utilizando La

Esquina, alguna charla, como se planteó ahorita, que se puede

hacer para que haya más tranquilidad ciudadana y, si es

posible, que es nos ayude a tomar más conciencia, a los

ciudadanos, sobre nuestros recursos naturales y cómo debemos

cuidarlos, protegerlos y... y participar en el esfuerzo para

que eso sea así, ¿ve? Esa es mi preocupación.

SR. SANTOS: Pues, gracias por su participación. Ha

sido bien... eh... buena.

SR. LEON ORTIZ: Pues, si he servido para algo,

pues,...

SR. SANTOS: Sí, gracias.

SR. LEON ORTIZ: ...me alegro mucho.

SR. SANTOS: Gracias.

SR. LEON ORTIZ: Y si hay alguna información que nos

traigan durante el Festival, pues, yo, desde el Centro

Cultural, puedo hacer gestiones. El Centro Cultural es ese

R2-0002716

46


edificio que queda aquí al lado,...

SR. SANTOS: Unjú.

SR. LEON ORTIZ: ...que nosotros organizamos los

artesanos y demás y hay una exposi...

SR. SANTOS: Yo entiendo que, ahora mismo, esa da...

esa información que trajimos...


SR. SANTOS: ...te la puedes llevar, por lo menos, la

que esté en español,...


SR. SANTOS: ...para que puedas...

SR. LEON ORTIZ: No y algunas...

SR. SANTOS: ...distribuirla, porque está...

SR. LEON ORTIZ: ...en inglés. Y algunas...

SR. SANTOS: Y te la pue's llevar toda.

SR. LEON ORTIZ: Sí. Eso...

SR. SANTOS: Es tuya.

SR. LEON ORTIZ: ...sería...

SR. SANTOS: Es tuya, las hojas, porque te vamos a

utilizar...

SR. LEON ORTIZ: Sí, porque...

SR. SANTOS: ...como portavoz...


SR. SANTOS: ...de nosotros, como parte de la

comunidad.

R2-0002717

47


SR. LEON ORTIZ: Y...

SR. SANTOS: Ya te adoptamos. Ya tú eres de nosotros

y tú nos vas a ayudar. Tú eres del equipo de trabajo.

SR. LEON ORTIZ: Bueno, yo estoy disponible, ya yo

estoy jubilado,... este...

SR. SANTOS: Pues, no te preocupes, ya...


VOZ SIN IDENTIFICAR: Tienes trabajo.

SR. SANTOS: Ya te vamos a dejar las hojas y yo me voy

a comunicar contigo entre el lunes y el martes para decirte qué

día te conviene a ti más que vengamos.

SR. LEON ORTIZ: Muy bien... este... Y yo, en todo...

durante... Yo trato de hacerlo todo durante el Festival

Jueyero,...

SR. SANTOS: 'Ta bien.

SR. LEON ORTIZ: ...que es una oportunidad que tengo

de ver a tanto compueblano...

SR. SANTOS: Distribúyelas, porque...

SR. LEON ORTIZ: ...y...

SR. SANTOS: ...ahí vas a ver información y ahí vas a

ver...


SR. SANTOS: ...personas que estén interesadas y las

puedes agrupar y, el día que hablemos,...


R2-0002718

48


SR. SANTOS: ...pues, tú me dices cuál es el día que

te conviene que yo venga.

SR. LEON ORTIZ: Sí, sí. Sí, sí, cómo no. Cómo no...

este... Yo me comprometo en eso... este... Pues, yo... eh... No

sé si hay algo más que...

SR. SANTOS: No, ya...

SR. LEON ORTIZ: ¿Estamos bien?

SR. TORRES: Y quiero mencionarte algo. Es Ramón

Torres, de la EPA. Y la decisión final que se tome de la

alternativa número 3 para la remediación, todo esta

información, análisis, el... un resumen del análisis de riesgo,

el por... de por qué llegamos a esa decisión, por qué nosotros

recomendamos eso, todo eso se va a capturar en un documento que

se llama el récord de decisión.

SR. LEON ORTIZ: OK.

SR. TORRES: ¿OK.? El récord de decisión es... en vez

de estar leyendo toda lo... la gama de... de...

SR. LEON ORTIZ: ¿Estudios y demás?

SR. TORRES: ...estudios técnicos, que quizás no vas

a entenderlo ))¿verdad?)), no ofendiendo a nadie, pero es

mucho... muy complicado,...

SR. LEON ORTIZ: Sí, sí, sí.

SR. TORRES: ...eh... se en... se prepara un récord de

decisión, donde se explican todas las alternativas, se explica

el análisis de por qué se escogió esta versus las otras tres y,

R2-0002719

49


entonces, pues, eso también va a estar disponible, una vez

terminemos el... el tiempo del... En septiembre 7 terminamos

los comentarios...

SR. LEON ORTIZ: Sí

SR. TORRES: ...e incluyen los co... la contestación

a todas las preguntas que usted nos acaba de hacer, van a estar

escritas en un documento que se llama "responsiveness summary",

donde vamos a recopilar todos los comentarios, tanto escritos

como verbales y se contestan en una... en el documento.

Pues, ese documento tiene tres partes; tiene la parte

de un "statement" que se dice de autorización, el récord de

decisión, que es el explicativo de todo y la última parte es la

contestación de todos los comentarios. Y eso, una vez... eh...

se firme, es un documento legal... eh... y ahí, pues, se plasma

lo que se hizo. Y ese documento también, una vez es final, está

disponible para el público, para que, entonces, ustedes lo

tengan y puedan decir: "Hey, ¿qué pasó aquí? Ustedes

dijeron..."


SR. TORRES: "...que iban a hacer esto. ¿Qué pasó?"

SR. LEON ORTIZ: OK.

SR. TORRES: ¿OK.?


SR. TORRES: Eso es para dejarlo saber, que también...

SR. LEON ORTIZ: Bueno, a mí, en particular

R2-0002720

50


))¿verdad?)), si no hay una alarma,... eh... si no hay necesidad

de medidas salubristas para con la comunidad, orientación a los

estudiantes en el uso y manejo de las aguas o del lugar, la

cuestión de la piel o demás,... eh... si los resultados,...

eh... por ejemplo, de las... de los casos de muerte que se

informan en algunos sectores, no están vinculados a o, si

algunos están vinculados,... eh... la cantidad ))¿verdad?)), el

estudio no propone o no me dice qué cantidad de personas de

Maunabo están en tratamiento, es una duda que tengo ))¿verdad?))

referente a... Porque se mencionaba de que, en Maunabo, sí

habían muchos casos de cáncer, habían casos de cáncer en la

piel, habían casos... muchos casos de enfermedades de riñones,

muchas personas, amigos míos y demás,... eh... que tienen

problemas de diálisis y demás y... eh... la gente como que

también ha cogido como una apatía mayor a estar en el río y a

ir a... a la boca, allí, a la playa, que es la más... eh...

cercana a esta área de contaminación... este...

Pues,... eh... las medidas salubristas, entonces, si

no es una alarma, pues, podríamos hacerlo con las instituciones

que hay en Maunabo,... eh... las escuelas, las iglesias y

demás, prepararles alguna hoja informativa más sencilla que

ésta, para que... eh... se orienten sobre los hallazgos y los

trabajos que se están haciendo sobre la calidad del agua de

Maunabo, el problema de las aguas subterráneas... eh... y...

eh... los procesos que se están llevando a cabo para... eh...

R2-0002721

51


tratar de resolver el problema, ¿no? Que... que esto se

resuelva en una forma satisfactoria.

SR. TORRES: Sí, no hay problema. Quiero que entienda

que esto no termina aquí. O sea, no termina... nosotros no

terminamos con el récord de decisión. O sea, viene la fa... la

fase del diseño y de la acción a tomar, que todavía "EPA" va a

estar aquí envuelto bastante tiempo.

SR. LEON ORTIZ: Ah bueno.

SR. TORRES: O sea, esto no es que vamos a terminar,

con esto, se acabó todo. No. Viene la segunda fase.

SR. LEON ORTIZ: Eso es bien importante.

SR. TORRES: O sea, es que no...

SR. LEON ORTIZ: Están...

SR. TORRES: ...en el proceso... en el proceso de

superfondo,...

SR. LEON ORTIZ: Diseño...

SR. TORRES: ...éste es el récord de decisión,

entramos en... que es lo que yo le dije, que es el documento

legal,...


SR. TORRES: ...ven... viene, entonces, la parte de

diseño y acción y la operación y mantenimiento. O sea, la EPA

todavía le falta por trabajar aquí. O sea, que no es que

nosotros vamos a ir de aquí,...


R2-0002722

52


SR. TORRES: ...este... ni la Junta tampoco. 'Tamos

presos aquí con ustedes, con este sitio tan precioso que hay...

Yo digo preso, pues,...


SR. TORRES: ...en el sentido de que estamos

comprometidos aquí, "so, which is fine". Y ahí vamos a estar

trabajando en eso. Y la... y el... el envolvimiento en la

comunidad continúa. O sea, esto no para aquí.

Terminamos... Esto es una fase. Volvemos. Esto es por

fases. Terminamos esta fase, pero vamos entonces seguir la

segunda. Cuando expliquemos... Hay que hacer otros "public

meeting" pa' discutir cómo va el diseño, cómo se va a

implementar, etcétera, etcétera, etcétera y se puede

continuar... este... ese esfuerzo dentro del "community

involvement plan" que nosotros tenemos, que es preparado

para... para eso mismo, para seguir... eh... en... e informando

a la comunidad sobre lo que está sucediendo en el proyecto,

porque es importante.

SR. LEON ORTIZ: ¿Y ustedes continúan recibiendo

información del Departamento de Salud sobre casos y sobre

situaciones o tratamiento? ¿O esa área habría que ser más...

SR. TORRES: Esa área...

SR. LEON ORTIZ: ...investigativo?

SR. TORRES: Esa área es una epidemiología y nosotros

no bregamos con el área de epidemiología... este... Eso es el

R2-0002723

53


Departamento de Salud y es que hace todos los estudios y las

estadísticas.


SR. TORRES: Nosotros lo que nos vamos mayormente es

en el área ambiental, en los contaminantes y lo que estamos es

tratando de evitar que se hagan... que... que tengan que hacer

un estudio epidemiólogo,...


SR. TORRES: ...porque si no, es que el problema está.


SR. TORRES: Si no, estamos tratando de evitar que el

problema presente.


SR. TORRES: Ahora mismo, claramente, con estos

hallazgos que le encontramos ahora, claramente le puedo indicar

a usted que el agua subterrá... eh... superficial y los

sedimentos y el suelo no tienen contaminante. Hay... hay

unos... eh... "plumes" que se encontraron bajando... que... los

penachos que le llaman, que son los que vamos a tra...

"address", a... a trabajarlos, por la sencilla razón de que

pueden representar un peligro para la salud humana y el

ambiente, antes de que llegue a los pozos... especialmente a la

salud humana, antes de que llegue a los pozos de PRASA, vamos

a corregirlos. Y eso es lo que estamos tratando de hacer.

SR. LEON ORTIZ: Qué bueno.

R2-0002724

54


SR. TORRES: ¿OK.?

SR. LEON ORTIZ: Qué bueno.

SR. TORRES: Pues, muchísimas gracias a todos por

estar aquí. Así que, con esto, pues, terminamos, así que nos

vamos a poner de acuerdo con Luis para cuadrar eso, ¿OK.?

Pues, dado... damos, entonces, por terminada la

reunión... este... Muchísimas gracias por la participación.

SR. LEON ORTIZ: Bueno, gracias a ustedes.

(Se dan por concluidos los procedimientos.)

****************

R2-0002725

55


CERTIFICADO DEL TAQUIGRAFO

Yo, Ricardo Alvarado, E.R. Reporter, miembro de FASYO

Reporters, CERTIFICO:

Que la que antecede constituye la transcripción fiel

y exacta de la grabación realizada durante la reunión de

celebrada en el sitio y la fecha que se indican en la página

uno de esta transcripción.

Certifico además que no tengo interés en el resultado

de este asunto y que no tengo parentesco en ningún grado de

consanguinidad con las partes involucradas en el mismo.

En San Juan de Puerto Rico, a 4 de septiembre de

2012.

__________________________

RICARDO ALVARADO

E.R. Reporter

****************

R2-0002726

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION 2

PUBLIC MEETING ON THE

MAUNABO AREA GROUNDWATER CONTAMINATION SUPERFUND SITE


Date: August 29, 2012, 7:00 PM

Location: Multipurpose Center

City Hall of Maunabo

Maunabo, Puerto Rico

Moderator: Brenda Reyes, Press Officer, EPA

Translated by: Aledawi Yigueroa

www.smielagainpr.com 787.872.5151 I 787.225.6332

1

R2-0002727

ATTENDANTS:

MRS.BRENDA REYES, Environmental Protection Agency

MR.LUIS E. SANTOS, Environmental Protection Agency

MR. RAMON TORRES, Environmental Protection Agency

MR. CARLOS O'NEILL, Environmental Quality Board

MRS. Nitza MARRERO FONTAN, Environmental Quality Board

BA.ARLYN GONZALEZ DIAZ, PRIDCO

BA.JORGE GARCIA DIAZ, PRIDCO

MR.MICHAEL VALENTINO, CDM Smith

MRS. SUSAN SCHOFIELD, CDM Smith

Mr. Leon Ortiz

MS.CAROL B. RODRIGUEZ

MR.JOSE LUIS SANCHEZ

****************

2

R2-0002728

3

PROCEDURES

MRS. REYES: My name is Brenda Reyes, and I am the

press official of the U.S. Environmental Protection Agency. We

are here today to present to you the proposed plan for Superfund

site ... the town of ... Maunabo or, as it is known in English,

"Maunabo ground water".

With me is Luis Santos, who is the project manager,

Ramon Torres, who is the acting director of the Response and

Environmental Remediation Branch of the Caribbean Environmental

Protection Division. We also have here Mr. Carlos O'Neill from

the Environmental Quality Board and Nitza, who is also from the

Environmental Quality Board and the people from CDM, who is the

contractor in this case.

Tonight, Luis will be making a brief presentation, and

we are here to answer questions.

MR. SANTOS: Thank you, Brenda.

Well, good evening, our intention is to

simple as possible, to bring the findings,

alternatives. Let's get started.

make this as

results and

(Pause)

Ortiz,

live in

MR. LEON ORTIZ: Excuse me, it is an order matter

MR. SANTOS: Mhm.

MR.LEON ORTIZ: Testing. My name is Jose Luis Leon

I am from Maunabo, "maunabefio"

the Maj agua neighborhood but

since since birth, I

I grew up my whole life

R2-0002729

4

here in this part of town. I'm officially a teacher, librarian

and cultural promoter ... urn ...

I think there is a problem because of the assistance of the

Maunabo town; no one has come in yet. I think I am the only

resident eh And for this not to be a matter of form) )

right?)), I request that you make a new invitation with a

greater emphasis on citizenship, for them to participate,

because this is a subject so delicate and so, so important. I

think there is confusion because of the suspension the

change of date and because of the upcoming "jueyeras" and among

other things. I'm surprised that the newspaper La Esquina, the

mayor and the members of the assembly or cultural center that I

in vi ted for Thursday are absent. On Monday, I told them it was

on Thursday ... uh because I belong to that center.

And ... uh... for us not to exhaust efforts)) Right?)) On a

pro forma process, I propose that we make an effort, before the

end of eh September, I know we don't have a lot of time,

to see how we can eh motivate and get more people ... eh

to participate ln this valuable information, you are

willingly providing us.

That's my approach.

MR. SANTOS: Ramon, can you elaborate more, what can we do with -

his ... ?

MR. TORRES: In the process ...

(Pause)

MR. TORRES: OK. This is Ramon Torres, from the Environmental

Protection Agency.

R2-0002730

Your concern, I was consulting with the Board of

Environmental Quality, and what we propose is to conduct

5

this pro forma, but ... eh ... make a "Public Availability

Session". This means talking to Luis next week, if you can, and

introducing him to everyone who is interested so that Luis can

answer to ... all questions they may have.

This was carried out-- for the record -- It was announced

in the newspaper twice, two times using ~El Nuevo Dia" and

using ~LA Esquina". So, we tried to use all means for the

community ... eh ... to get informed.

Yes, we understand, is under statute, we understand that,

eh, there are other activities out of our control, but I

I understand that we can do this pro forma, carry it out,

you can see it, ask all the questions you have, we' 11 gladly

answer them, and afterwards, an availability session where Luis

Santos and representatives from the Board will be available

here. Or we have to find a place where we can meet and I will

ask you to help us bring people who are interested.

All documents about the project are available to the public

here in town, right? They are at the library. I urge you to

look at all of this, see the documentation that we have given

and come prepared to ask any questions or talk about any issue

you may have ... eh ... I understand that, with that, we comply

with everyone, in order to eh to keep moving this

project forward and resolve the situation we have here, in

Maunabo. Okay?

(Pause)

MR. LEON ORTIZ: Jose Luis Leon, from Maunabo.

R2-0002731

6

The problem is that the non-attendance)) right?)) Of

Maunabo' s public to this activity, all except me eh

then, it is proof that there was no effective communication. But

on the other hand, it also proves)) right?)) the seriousness in

the lack of consciousness and how a situation so delicate, then,

in terms of community environmental education, we are so belated

on generating concern and greater community involvement to help

solve the problem eh ...

However, eh If I stay, it would then be pro forma,

I would be accepting all the information that you provide ... and I

have so many questions)) right?)) And so many things in mind

about this in particular, because historically, we have not been

responsible with our waste management ... eh ...

We used to throw the trash at the Mala Pascua to the sea for

years and years and years. And that water treatment plant was

there throwing waste for years and years and years.

Eh ... Then ... eh... It seems to me that, well, I, as a citizen

of this country, uh... I have... I am committed to getting more

people, students, and Maunabo investigators to participate, eh ...

the public administration, religious institutions, because

Maunabo has that capacity and has demonstrated it in projects

such as the ... that of ... eh ... the wetland, and the tunnels.

Those are all projects with a lot of community support.

MR.TORRES: Mhm.

MR.LEON ORTIZ: Then, then I am surprised

absence of the public. Then, eh therefore

not know.

by

eh

the

I do

The solution that you are providing me is that eh

is synonymous to the the plans, well they are difficult to

change, at least, as the activity was conceived for today ...

R2-0002732

MR.TORRES: Mhm.

MR.LEON ORTIZ: ... By that approach that you Mr. Santos or any other expert in

eh ... linked, then if we gather the

make, the

7

for field

community, to come answer questions and let it be before the end of September so that you ...

MR.TORRES: Mhm.

MR.LEON ORTIZ: carry on that influence ... this ... But

you put me in a rather delicate situation .. .

MR.TORRES: No, no, no, but what we are .. .

MR.LEON ORTIZ: This is an inter ... interlocution what we

are going to have.

MR. TORRES: Enter ... Correct. But I mean, we

obviously complied and they are you are present and I

acknowledge that you are here. And this is going to be done with

one person or, if no one had come, we here have a

representative of PRIDCO. So, not from ... other companies. So,

here we have representatives who are keeping an eye on

this. They can also comment. You can comment. So you are

respected as everybody else.

MR.LEON ORTIZ: Sure.

MR. TORRES: And that that's why I do not want you to

waste your time or by being able to come here and and

with all due respect for the others who came here. But that is

why I am giving the second option, which would also be That

is, we proceed with this, you already understand I get the

information the the of what is happening and with

R2-0002733

8

the lawyer present and we can then have a dialogue)) OK.?)) And

hence you have sufficient information so that next week eh

I' 11 tell Luis to start looking for a place tomorrow and

call you. . . talk with you to agree and Luis is available. I,

unfortunately, I won't be available, this but eh

Brenda will be there to facilitate the dialogue. And if we have

to resubmit all the information, we will present all the

information.

MR. LEON ORTIZ: Sure.

MR. TORRES: So, it's not

community's right to understand and

that we'll

listen. And

cut off

we repeat:

the

we

we... we're talking,

to cancel it, but we

And it is your right

meet the submission requirements,

unfortunately, because of Isaac we had

quickly give you the privilege)) right?))

to have this

your questions

them. Okay?

review, discuss, present your concerns,

concerns and we have our obligation to answer

MR. LEON ORTIZ: Eh ... well ...

MRS. REYES: Look, Don Jose, I suggest And this is

what comes to my mind ... because it has happened to us in other

cases, where, there is a greater interest than it generated

well, a public meeting. In your case, you are saying that there

are other interested persons. We did the due process, this was

published in the newspapers, handouts were made, these handouts

were delivered, we know that there was a cancellation, but

we solved the problem, no?

It occurs to me that maybe)) and I talked it over here

briefly) ) we can meet in the library, request access to the

library and you bring us a group of people who are interested.

Luis and I will be there all afternoon, we can make the

R2-0002734

presentation,

therefore, a

that we have

festival, but

try to answer all questions eh

time that is convenient, because we ... it

the thing the the situation

also... also)) I mean)) it was published

is

of

in

newspapers and therefore the word was spread. What I want ...

MR. LEON ORTIZ: Yes, yes.

9

and,

true

the

the

MRS. REYES: is for you to understand that this was

announced eh But then, to comply with your request if

you tell us, you call Luis, Luis can contact me, we're in the

same office, we can speak on the Phone eh I can come

with him on Wednesday or Thursday of next week.

MR. LEON ORTIZ: I'm ...

with your observation and I

between you and us all eh

dynamic and that eh

right?)) or the urgency that

uh ... eh ...

I would like ... Look, I agree

believe that the relationship

should be and has to be

according to the emergency))

of the problem at hand ...

Yes, what happens is that I know that ... we have the strength,

talent and support to coordinate and to do this eh an

encompassing knowledge movement about our environmental

situation ...

MR. SANTOS: Mhmm

MR. LEON ORTIZ: and our health ... eh ... our own,

Right? And so, I'm surprised by the lack of people. Now, this

approach your having about ... when when we require or have

the conditions, to meet eh I think that we should have

that always ... uh ...

Mrs. REYES: Yes, no, that's all the time.

R2-0002735

10

MR. LEON ORTIZ: with these open communications to

... that if they have to go to school or have or inform ... eh

or some interest group that wants to hear your opinion

eh it can be done ln a dynamic way. Actually, they don't

need to be all but ...

MR. TORRES: Yes

MR. LEON ORTIZ: ... someone who knows technicalities ...

MRS. REYES: Yes, we ...

MR. LEON ORTIZ: the problem.

MRS. REYES: as part of the Superfund process

Obviously, the super fund process of of Superfund

cases required in eh with what is known as 11 community involvement 11 which involves the community

community involvement in all parts, it can be the

community, but maybe it can also be a government entity, it

can be a private entity, it can be residents ... Of course,

what I want you to understand is that we are willing, my

partner and I will have to talk to Mike)) Right?)) For him

to come and be with us, we seek a place, the library and

you bring your people.

Mr. LEON ORTIZ: Ok, well.

Mrs. REYES: We're going to go over this case

specifically. Any additional environmental concern; because you

listed a number of practical concerns of mismanagement that

occurred in the past. Sometimes those practices don't concern

me, as an agency, but it concerns the Environmental Quality

Board, or the Health Department.

What I ask is that, at that meeting we will have next

week, we can talk about it and answer questions about the case

and then, once we are done, we can sit and see how we can help

R2-0002736

11

channel these concerns to the corresponding agencies. Because

not everything is going to be in EPA's hands. I can assure you

that.

Mrs.

then, if


REYES: But we can

you have to write

help

a

"email", a memo, it will be done ...


channeling

if Ramon

them. So And

has to write an

Mrs. REYES: and he means. Because it happens on all

sites. The other day, Luis and I had a meeting in PREPA Palo

Seco and there were a number of concerns raised by the Catano

Palo Seco community ... eh in relation to a number of things

and I gave them my phone number and some other contact numbers

and helped ...


MRS. REYES: for them to channel their concerns.

But really, the community must get together .. .

MR. LEON ORTIZ: That's why .... this .. .

MRS. REYES: to channel these ... those things,

because it can't be just you.

MR. LEON ORTIZ: That's why, that's why. And I know that ...

that there are... I mean, we are a an old town ancient,

Taino, but ... ancient ...

historical studies. Then,

this And This is confirmed by all

this plus a lot of participation

you know, organized.

did not expect this.

So, I'm completely surprised, truthfully. I

MRS. REYES: It was not for lack of trying.

R2-0002737

12

MR.LEON ORTIZ: Well, steps were taken, but the message was

lost.

MR.TORRES: Yes, no ... no ... or they did not come ... chose

not ... not to come.

that we still have

period ...

But I understand your concern and remember

a Public comment eh a comment

MR.LEON ORTIZ: Yes

MR. TORRES: and that if they could not come and have

written comments, please submit them before September 7, for us,

then ...


MR. TORRES: answer them. That is that opportunity

can be dynamic, "face to face" or they can decide, if they can't

come, to do it through a uh ... a writing, right?


MR.TORRES: But because of that, I understand that we can

continue; and if they arrive later, later it is. No problem. But

I understand that we should continue with the talk and

presentation for the ones that are present, so they understand

what is happening; and then, as a second chance

the ... the public availability, where uh

Luis and Michael, when you can, if you can,

given and, then, you can have that dialogue ...


we give them,

where Brenda,

uh it'd be

R2-0002738

13

MR. TORRES: More Direct. Because an "availability" is less formal ... eh ... and it's ... This is a formal requirement ...

MR.LEON ORTIZ: Yes

MR. TORRES: by law ...

MR.LEON ORTIZ: Yes

MR. TORRES: this that must be done. And then, that "public availability session" I have done it many times and it is even more effective, because it is the the "One on One" and is a period of time ... eh ... significantly longer, right?

MR.LEON ORTIZ: Yes, yes.

MR.TORRES: OK?


MR.TORRES: So I think that if we are set, then, we can continue, then, with the work.

MR.LEON ORTIZ: Well, yes ...

MR.TORRES: OK?

MR.LEON ORTIZ: I'll sit ...

MR.TORRES: OK. And listen. And if you have ...

MR.LEON ORTIZ: dedicated.

MR.TORRES: Exactly. Well, feel honored. And thank you very much for being here.

MR.LEON ORTIZ: Thank you.

MR. SANTOS: Thanks, Ramon Thanks, Jose Luis. And then

resuming with this, this we would be available to, in one

afternoon, be in the in the library, sit there and you and

everyone you can summon, to bring us Verbal or written.

Preferably, from now on, we would prefer it to be in writing.

But we can be in cum ... in ... in ...

R2-0002739

14

MR.LEON ORTIZ: I hope that the assembly has an opinion

eh ...

MR.SANTOS: Yes

MR.LEON ORTIZ: That's why, I tell you, that if we don't put

interest ...

MR.SANTOS: So. Well, let's continue. The focus of this

study ... the general objectives of this study is to define the

nature, extent and sources of groundwater contamination in the

Maunabo Township, assess the risk to human health and ... and to

the environment, and do a remedial investigation and a

feasibility study.

To get situated, ln the map of Maunabo, we have four

drinking water wells that supply sixty percent of the community

eh ... drinking water for the area. Well number 1, 2, 3 and

4. They are all PRASA' s and provide the drinking water supply

to sixty-five percent of the population.

MR.LEON ORTIZ: In total? For Maunabo?

MR.SANTOS: In Maunabo. The neighborhoods

are drawn on other sources.

neighborhoods

MR. LEON ORTIZ: Ah, when you

It's just from downtown?

So, it's not in total is

MR.SANTOS: The urban section.

MR. LEON ORTIZ: The urban section, which may include

Talante, Bordaleza ...

MR.SANTOS: and their surrounding neighborhoods.

MR.LEON ORTIZ: The flat parts?

R2-0002740

15

MR. SANTOS: Exactly .... this ...

(Several people speak at once, without a microphone, the record

is not understood.)

MR.SANTOS: Continuing.

MR.LEON ORTIZ: I'm bringing .. .

MR. SANTOS: Yes, yes. To buy .. .

MR.LEON ORTIZ: ... interact .. .

MR. SANTOS: Yes Well, I stop, you talk, you identify

yourself and we continue.

MR.LEON ORTIZ: Exactly.

MR.SANTOS: OK. And this is the Superfund process. And this

is for us to see where we are. A site in the Superfund process

is discovered, a preliminary study is made, this preliminary

study carries a list under the Superfund, hence, an

investigation is carried out of the site, from there, the data

is taken to a mathematical model where it would be standardized

and from there, to a National Priority List.

All Every site that comes to the National Priority List

eh goes through a process of "investigation time" research

and feasibility studies, that's really what we came here for.

And at this point is where we are.

MR.LEON ORTIZ: OK.

MR.SANTOS: Before the remedial and feasibility

studies, which were completed prior to the record of decision.

So, we are just at the interface between remediation and

feasibility study and the record of decision.

R2-0002741

16

OK. The background history: the supply system for drinking

water of the town of Maunabo has four wells: Urbano, Bordaleza,

Calzada and San Pedro. The water comes from these four wells and

is mixed and, more or less, gives supplies to fourteen

thousand residents of the village of Maunabo and surrounding

neighborhoods. In 2005, the Puerto Rico Aqueduct and Sewer

Authority ( PRASA) detected Volatile Organic Compounds in well

No. 1. The Health Department ordered to stop the the

supplying of water from that well and, automatically, the

Authority eh installed some wells some filtration

systems to treat the water. Once that water meets federal

standards, the Department of Health allows them to reinstall the

... the well in the network.

MR. LEON ORTIZ: This I have a question there. So

that means the well 1 and the well 4, which are the ... are the

highest contaminants ...

MR.SANTOS: Well ...

MR. LEON ORTIZ:

water was contaminated))

that's more or less ... ?

and Health test proved that the

or EPA?)) For non-consumption? Or

MR. SANTOS: What happens is this ...

MR.LEON ORTIZ: In 2000. Oh and what year was it? Was

it 2000?

UNIDENTIFIED VOICE: 2.

UNIDENTIFIED VOICE: 2002.

MR.SANTOS: In 2002. What happens lS the following.

MR.LEON ORTIZ: In 2002.

R2-0002742

17

MR. SANTOS:

regulates the sale.

federal standards for

PRASA sells water. The Department of Health

The Department of Health adheres to

drinking water.


MR.SANTOS: Any pollutant or any list ... all substance

which is listed, which exceeds federal water quality standards,

does not meet the requirements to be sold. Therefore, once

detected, the Department of Health prohibits PRASA from selling

this water. And that's what happened there.

consume.

MR.LEON ORTIZ: To sell that water.

MR.SANTOS: Yes, because PRASA sells it and bills you.

MR.LEON ORTIZ: But consumption. That is consumed.

MR. SANTOS: Well, sell, sell. PRASA sells and people

MR.LEON ORTIZ: The Department of Health ...

MR.SANTOS: Regulates the sale.

MR. LEON ORTIZ: doesn't get involved in the ... in

the ... ? So Is, but it also gets involved in the regulation

for consumption?

MR. SANTOS: The. . . The ...

MR.LEON ORTIZ: And besides that issue of sale that can

be there ...

MR. SANTOS: Well, it is a sale, is a sale. They sell

water. And that water has to meet the standards.

MR.LEON ORTIZ: OK.

R2-0002743

18

MR.SANTOS: And the entity having jurisdiction to

ensure they comply with these standards is the Department of

Health.

MR.LEON ORTIZ: Among others.

MR.SANTOS: The Department of Health is the one that

says, that constantly monitors, monthly, PRASA so that the

selling water meets the federal standards.

MR.LEON ORTIZ: And in 2000 or 2000 ...

MR.SANTOS: That was in 2002, was found ...

MR.LEON ORTIZ: In 2002?

MR.SANTOS: it was found that well number 1 didn't

comply with those standards.

MR.LEON ORTIZ: well number 1?

MR.SANTOS: Number 1.

MR.LEON ORTIZ: And that was the alarm that ... ?

MR.SANTOS: That was the alarm. It was ordered to stop

selling and they decided on treatment and were allowed, with the

treatment, to continue selling. Because treatment reduced the

... eh the ... the substances.

MR.LEON ORTIZ: And was the treatment effective?

MR.SANTOS: Yes, it was effective. That was why they

allowed them to continue.

MR.LEON ORTIZ: And they let them continue?

MR.SANTOS: And so far, they are selling.

R2-0002744

19

MR.LEON ORTIZ: And the Department of Health also

allowed them to continue selling that water?

MR.SANTOS: Yes, yes.

MR.LEON ORTIZ: Because I had ... Well 1 ...

MR. SANTOS: Well ...

MR.LEON ORTIZ: ... the levels had decreased ...

MR.SANTOS: 1, with trea ...

MR.LEON ORTIZ: ... standards ...

MR.SANTOS: with treatment.

MR.LEON ORTIZ: ... contamination ... With treatment?

MR.SANTOS: With the treatment the standard values were

met.

MR.LEON ORTIZ: In this well?

MR. SANTOS: In this well. With the other wells there

was no problem.

MR.LEON ORTIZ: Still no problem?

MR.SANTOS: OK. 2005. An inspection is performed we

are, in the Superfund process, where the Maunabo 1 and 2 have

levels below standards. The "MCL" are the federal water quality

standards. In 2005, an investigation is conducted to identify

the sources of pollution and, until that time, we could not tell

what the cause of that contamination was.

In 2006, the site is included in the National

List. Basically, what I'm reviewing is the table di

above, the Superfund process.

Priority

eh ...

R2-0002745

20

MR.LEON ORTIZ: In 2006 it goes where? NPL?

MR.SANTOS: It is included on the National Priority

List ...

MR.LEON ORTIZ: That's ...

MR.SANTOS: ... federal.

MR.LEON ORTIZ: Total government ... ?

MR.SANTOS: Federal.

MR.LEON ORTIZ: Federal ... eh ... OK. I mean, the case was considered an emergency and was addressed?

MR.SANTOS: Yes, it was as we speak, as we speak here. The site is ... is detected when ... at the time the Department of Health prohibits the sale of that water ...

MR.LEON ORTIZ: OK.

MR. SANTOS: standards. There was there was a study of

because there is a violation of the a preliminary study. This was in 2004, the site)) 2005)) and this leads to the

national priority list in 2006.

MR.LEON ORTIZ: OK.

MR.SANTOS: And meets the EPA requirements. This is already EPA.

MR.LEON ORTIZ: Alright.

MR.SANTOS: OK. We'll continue. In the ... from 2010 to 2012, the EPA ... And we are still in this process.

MR.LEON ORTIZ: Here?

MR.SANTOS: We're here.

MR.LEON ORTIZ: OK.

MR.SANTOS: Now this is it ...

MR.LEON ORTIZ: OK.

R2-0002746

21

MR. SANTOS: and we are here in this place ...

MR.LEON ORTIZ: We take action ...

MR.SANTOS: In this place. Action was taken and, during the 2010 to 2012, EPA initiated and completed a Remedial Investigation of the site. In 2012, EPA initiated and completed

the the following documents: the human health risk assessment, the ecological risk assessment and the feasibility study. Those studies are on the table.

MR.LEON ORTIZ: Yes I have one there.

MR. SANTOS: And are in the depository, in the Library of the City Hall.

MR.LEON ORTIZ: I did not see those. They were ... No, no ... Well. ..

MR.SANTOS: They are there.

MR.LEON ORTIZ: I cannot say they were not.

MR. SANTOS: But go check them out and, if they're not there, ...

MR.LEON ORTIZ: And I ...

MR. SANTOS: they are, but if not ...

MR.LEON ORTIZ: But they are ... uh ... ? I ...

MR.SANTOS: Yes

MR.LEON ORTIZ: Well, of course.

MR. SANTOS: So, all this investigation, from 2010 to 2012, concludes that the risk assessments are completed ...


MR. SANTOS: and completed the ecological risk and human risk assessments. And a feasibility study is made with the results.

MR.LEON ORTIZ: OK.

R2-0002747

22

MR.SANTOS: OK.

MR.LEON ORTIZ: That was this year, in 2012?

MR. SANTOS: 2012. Completed. It began in 2010 and was completed in 2012.

MR.LEON ORTIZ: Ah.

MR.SANTOS: So, this is recent.

MR.LEON ORTIZ: Yes

MR.SANTOS: OK. Here are studied. A preliminary study was town, all identified areas that causes ...

the made were

MR.LEON ORTIZ: Of pollution?

three areas that covered identified as

that were the whole

possible

MR.SANTOS: pollution and got that, of all these five areas that we studied, we focused on three areas. And that's where wells were installed. Sixteen wells installed, plus four wells. . . with the ones from PRASA, that makes twenty. And those are the sampling network ...


MR. SANTOS: giving base to the results.


MR. SANTOS: OK. Field activities consisted of groundwater samples samples of the preliminary, which was what I mentioned, we collected soil samples, samples were collected and wells were installed. Groundwater samples were collected and surface water and sediment samples were collected in the Maunabo River. That is, we covered everything

R2-0002748

23

everything, the whole environment. Preliminary, there is soil, groundwater, surface water and sediment in the river.

MR. LEON ORTIZ: In the specific area you indicated or, for example, in the river, how the ...

MR. SANTOS: In the river, was ...

MR.LEON ORTIZ: ... up to the mouth?

MR.SANTOS: Well, in the river somewhere before the town ...

MR.LEON ORTIZ: On the bridge ... ?

To the mouth. From

MR. SANTOS: From before the town, passing across the south, up to the mouth.


MR.SANTOS: OK. No specific contaminants were found in the surface water sample locations in the river. Meaning that in the river, no contamination was found. No specific contaminants in the soil locations were found. Soil contamination was not found.

So; what was found? Three plumes of "Dichlorethane", tetrachlorethylene and diclorethylene. These three plumes were those found in the groundwater. That is, surface water, sediment and soil, had no problems. The problem occurred in the groundwater. And there were three plumes found.

MR.LEON ORTIZ: OK.

MR. SANTOS: Where could these plumes have come from? Who who'd be the sources? Look, it could have been the dry cleaners, could have been degreaser, degreaser therefore any type of formal or informal business in the area, which was dedicated to to use of these substances for cleaning and handling ... a process. It could be domest~c ...

MR.LEON ORTIZ: Engines and things?

MR. SANTOS: industrial ...

It could be domestic, could be

R2-0002749

24

MR.LEON ORTIZ: Like Batey Columbia, there was an area there for a long time dedicated to machinery, particularly ...

MR.SANTOS: Exactly.

MR. LEON ORTIZ: that what they did was eh work with trucks and pull the oils ... to ...

MR. SANTOS: So ...

MR.LEON ORTIZ: to the ground.

MR. SANTOS: that these products that were found, the origin could be from the "dry cleaner" or "degreaser".

MR.LEON ORTIZ: OK.

MR. SANTOS: investigated. And the

the three stars. were found.

OK. Here, this illustrates the three areas three plumes. Here is one, the second one Where the stars are is where the plumes

MR.LEON ORTIZ: OK.

MR.SANTOS: Plume is because it is Underground. "Pl umacho" would be if it was air surface.

under water. blowing on the

OK. From the point of view of human risk, all soil parameters are within EPA ranges. So, what ... Let's go back. In the soil there is no pollution problem. In all sampled areas of screening, which was almost the whole town, and in none of the soils we found that there was any problem to human risk.

MR.LEON agriculture? ...

ORTIZ: So,

MR.SANTOS: The land.

lS it safe

MR.LEON ORTIZ: ... developing ... eh ...

MR.SANTOS: Yes, sir.

for

MR.LEON ORTIZ: ... and all. Is it safe for that?


for

R2-0002750

25

MR.LEON ORTIZ: Livestock, bananas ...


MR.LEON ORTIZ: OK.

MR.SANTOS: We're talking about ecological risk to

health. The potential concern about the chemical substances that

came up ended in no significant risk to the EPA ... the ...

to EPA to the environment. That is, first we speak of

humans. What I'm talking about here 1s the environment. This is

the risk to a the environment. And that risk to the

environment has no The environment is not at risk. What

we're talking about is whether plants, animals are not at risk.

MR.LEON ORTIZ: Nor the food chain?

MR. SANTOS: Nor the food chain. What were the

alternatives for dealing with the four ... the three plumes?

The alternative number 1 was no action. And it is a base.

It is ... It is always used as the basis for verification ... to

as a benchmark.

Alternative number 2 consists of an attenuation sampling.

Let nature make its modification of eh ... the contaminants

and we monitor them, to see how the process goes

degradation.

of

Alternative number 3 would be to continue the monitoring,

but also inject air, so that it accelerates the the

decomposition of these substances and decreases the levels in

the water.

MR.LEON ORTIZ: And that air when go?

MR.SANTOS: That air goes to injected to the ground.

Where would it

to ground. It is

R2-0002751

26

MR.LEON ORTIZ: Which means, that it would come out of the underground to the surface?

MR. SANTOS: It is inj ec is injected directly into the soil, promoting that the contaminant that is there, in that water, accelerates its degradation. That is ...

MR.LEON ORTIZ: Degradation as natural, with the ...

MR.SANTOS: Natural.

MR.LEON ORTIZ: with ... with ... with ...

MR. SANTOS: We ...

MR.LEON ORTIZ: acquisition of air?

MR. SANTOS: we We are accelerating what nature would do.


MR.SANTOS: Nature, if we don't do anything, nature will degrade it on its own.


MR. SANTOS: With this air, we promote the degradation in less time.

MR.LEON ORTIZ: Alright. Then, the air coming out, Is it contaminated or have you already degraded it, before ejecting it to the atmosphere?

UNIDENTIFIED VOICE: degraded (speaking without

microphone, not heard). We understand that it is degraded,

because we parts per million and, when it comes out,

it ends up in a way that it cannot even be detected.

MR.LEON ORTIZ: What cannot be detected? That is, skin

problems, eh ... by direct contact, breathing ...

R2-0002752

27

MR. 0' NEILL: Carlos 0' Neill, of Environmental Quality

Board. The air will come out ... this we are talking with a

range of parts by "billion" in the water which are very small.

Once ... If any ... eh these gases escape from the air,

eh the quanti ties are so small they cannot be detected in

the air and do not have any health effect on health or ... the

the ecosystem.

MR.LEON ORTIZ: Now I understood that Hey, it is

that, then, by putting eh ... that system ... it takes air

to groundwaters ...

MR.SANTOS: Groundwater ...

MR. LEON ORTIZ:

acceleration process begins,

organisms.

and then, that's where the

like natural decomposition of these

MR.SANTOS: of these substances.

MR.LEON ORTIZ: Of those substances. So, it is not to

extract ... Because I thought it was ...

MR.SANTOS: No, not extract.

MR.LEON ORTIZ: eh get it to the outside.

MR.SANTOS: No,

groundwater ...

no, no, no.

MR.LEON ORTIZ: Now I understand.

Inject air into the

MR. SANTOS: and that promotes the degradation of

these substances to acceptable levels.

MR.LEON ORTIZ: Alright. I understood.

R2-0002753

28

MR.SANTOS: In Alternative 4, it would be

bioremediation of the place. Since you would be using chemicals

injected underground, in groundwater, to accelerate the

degradation of these compounds and that when and lower the

levels and make them acceptable within the water quality

standards. The alternative we chose was number 3,

MR.LEON ORTIZ: Yes

MR. SANTOS: that was the one I explained. It

was inject and monitored. And basically, this would be a a

a graph of how Here, you see that is being injected,

these tubes, to groundwater, groundwater promoting this

degradation and have those and that these and those

compounds, already detected a reduction in their levels.

MR.LEON ORTIZ: I understand. Do they you a fairly

clear idea of how far does the pollution go? How much time, more

or less, the decontamination will take? And one thing that

I read that worried me was that it talked about a round pa

eh ... you thought that, in a round ... I do not know the term

used to describe what what was the round . . . eh I think

it is just that, airing eh

problem, more or less? But what

involve ... eh ... of these systems ...

MR.SANTOS: Well ...

could already resolve the

what does a round

MR.LEON ORTIZ: on 1n ... tune with ... eh ...

the the analysis you have done on the amount of

contaminated groundwater that exists?

R2-0002754

29

MR.SANTOS: OK. How long we have to keep injecting air?

That's going to be determined by the monitoring.

MR.LEON ORTIZ: OK.

MR. SANTOS: As we progress the number of days using

air, we follow ... followed by monitoring, and that will tell us

how effective we are being, and when we understand that we have

already corrected the situation. So as monitoring goes it's

linked to the injection. Ah ...

MR.LEON ORTIZ: At the round?

MR.SANTOS: The rou ...

MR.LEON ORTIZ: At the round?

MR. SANTOS: A round. A ... one is linked to the

another. I cannot do the injection and forget about monitoring,

because I'm not detecting what it is.


MR.SANTOS: So, I have to see how long I have been

injecting in that round, what were the

have and how much ... what percent I have

results; what levels

eh ... degraded.

MR.LEON ORTIZ: But you are starting from the

premise that ... eh ... the contamination event is already

controlled? What, it no longer exists?

MR.SANTOS: Well, we are starting from the premise

that ... to date, we have not detected a source contamination.

I

R2-0002755

30

MR.LEON ORTIZ: At today's date?

MR.SANTOS: There is no source of the existing

Contamination. Where it comes from, the origin, it is unknown.

And if it was releasing now, no, we would have detected it

in ... in in the two monitoring rounds, the two rounds were

basically the same. They were six months apart from each other,

and the results were similar. What

there is no active release ...

which indicates that

MR.LEON ORTIZ: Which means that ... ?

MR.SANTOS: of pollutants.

MR.LEON ORTIZ: weren't there more ...

MR. SANTOS: No source. No ...

MR.LEON ORTIZ: No source.

MR.SANTOS: Right now, there is no source.

MR.LEON ORTIZ: Well, then, I wanted to ...

MR. SANTOS: The source was there and... and... Was

released

MR.LEON ORTIZ: Y ...

MR. SANTOS: and we have the ... the . .. effect. But

who caused it? That is what we have not yet eh

discovered.

MR.LEON ORTIZ: Well, we have eh at least, I

have analyzed the situation and I think the source was the

mismanagement of the Processing Plant with the wastewater of the

Water and Sewerage Authority. And, as soon as the monster that

was there was repaired, then eh the thing, therefore

R2-0002756

31

improved, right? Because

there that cost a few ... eh

eh it received an injection

thousand dollars~ or millions.

So then, in fact, that means, then, that those improvements to

the treatment plant paralyzed the source of contamination.

MR.SANTOS: We must start from the premise that

treatment plant is a water treatment plant for wastewater. It is

industrial.

MR.LEON ORTIZ: Wastewater.

MR. SANTOS: So. And there

contaminants that are industrial.

there we are detecting

MR.LEON ORTIZ: Go. Look at that.

MR.SANTOS: Some are ... Because what ... what is

wastewater plant wastewater treatment entering the

from Aqueduct is wastewater. Water coming from the

public easements.

plant

is

MR.LEON ORTIZ: But the outcome of

waters, ineffective, released down there ... eh

those treatment

to the

surface waters and to eh In other words, the chemicals

that they were using to try to correct the serious

situation ...

MR.SANTOS: This particular chemical ...

MR.LEON ORTIZ: No ... No ...

MR. SANTOS: that is detected ...

MR.LEON ORTIZ: It hasn't registered ...

MR. SANTOS: no ... no ... there's no connection.

R2-0002757

32

MR.LEON ORTIZ: Because the other suspicion that we had

was that when a landfill was established in the Neighborhood

of Tumba' o ...

MR.SANTOS: Mhmm.

MR.LEON ORTIZ: ... which is between that bridge

in the dam and the other bridge, which is eh ... ? all the way

in Palo Seco, established a landfill. And it was the year when

Union Carbide had been sued and had to close down in Yabucoa and

eh our experience is that there were toxics that were

thrown there even when a mesh was put there. And you never know

if those contaminants came from the Roosevelt Roads. But we have

no information to prove that data, because I asked and it seems

that there was no control, in that period, of whom were those

who carried materials and deposited.

MR.SANTOS: This is the purpose of these conversations.

Because right now, whatever is there is already there and we

come to say how we will remedy it.

MR.LEON ORTIZ: But you did not study this area.

MR.SANTOS: But what we will ... what we will see

is who were the sources and that will help us detect.

any information that the community has that can

determine or detect what possible companies, which

entities were responsible, we will help deal with this

... with the process ... of ...

MR.LEON ORTIZ: Basically ...

MR. SANTOS: remediation.

That is,

help us

possible

... with

R2-0002758

33

MR.LEON ORTIZ: there eh they brought

toxics from the Union Caribe in Yabucoa.

MR. SANTOS: That information ...

MR.LEON ORTIZ: ... and from the Sun Oil.

MR.SANTOS: is excellent.

MR.LEON ORTIZ: And from the Sun Oil.

MR.SANTOS: This information is excellent. And all the

information you have about this, bring it. Because we can

analyze and we will help find who were responsible for this

contamination.

MR. LEON ORTIZ:

investigationto ...

Well, we would have to make an

MR.SANTOS: We are willing to do it.

MR.LEON ORTIZ: ... to ... this ... see ... eh ... the

managing files from that landfill ...

MR.SANTOS: Mjm.

MR.LEON ORTIZ: ... if a record was kept ...

eh ... of those ... of ... of that garbage dumped there.

I mean, I do not know if that exists. A ... up there ...

I asked, neighbors and others told me that happened,

and ... I can't give more information ...

MR.SANTOS: This study has two functions:

R2-0002759

34

One is to assess the concentration and size of contamination at

the site and the other to detect who were the polluters.

MR.LEON ORTIZ: Well ... eh ...

MR.SANTOS: At the time, we have been successful

determining what, at what levels and how we will resolve.


MR.SANTOS: But we have not been successful in finding

who was responsible.

MR.LEON ORTIZ: Who was?

MR.SANTOS: And any information that the community has

will serve as extra support.

MR.LEON ORTIZ: Because, for the record, I want to

highlight that Maunabo has an unemployment rate of sixty-four

percent, there is no manufacturing. Hardly, uh. . . there have

been one or two things that arrived for a few months and or

two years and then they leave, this under conditions of

of little economic stimulus and a significant beauty eh

... of the town and its surroundings.

MR. SANTOS: Continuing. So basically, this is the

presentation. We have tried to make it as simple as possible.

You can find all the documents that we used to get to this

these conclusions in the depository. This was in

collaboration with ... This was a project that was led by the

EPA eh ... the Environmental Quality Board is our partner in

the job and the municipality of Maunabo helped a lot with the

connections and the ...

R2-0002760

35


MR. SANTOS: the job.

MR.LEON ORTIZ: Sure. Right.

(Pause)

MR.LEON ORTIZ: Thank you ...

MR.SANTOS: Jose Luis ...

MR.LEON ORTIZ: ... Mr. Santos.

MR.SANTOS: here I am at your service.

MR.LEON ORTIZ: I know.

MR.SANTOS: Now, from the start ... ever since we spoke

Initially we talked eh I promise that, either on

Monday, Tuesday, in the afternoon, Wednesday or Thursday,

whatever we decide, to be present in the library, which is where

the depository is and we can collect questions, doubts and all

the docu all the information that comes in. Now, by this

time, we would like you to bring whatever you have in writing.

MR.LEON ORTIZ: Written?

MR.SANTOS: Yes, written, because this was the forum to

bring it was verbally.


MR.SANTOS: And we really, unfortunately, didn't have

MR.LEON ORTIZ: Yes

MR. SANTOS: the assistance we expected.

R2-0002761

36

MR.LEON ORTIZ: Yes, I expected a representative from

the Assembly, a Cultural Center position, position of the I

I expected more ...

MR.SANTOS: But you are right, well ... this ...

You've helped a lot, because we've aimed to different roads

that once we are analyzing the the this process the

response to this activity, we need to consider what you said.

important

problem,

taken ...

MR.LEON ORTIZ: Thanks ...

it is to us if you don't

which can be even worse if

MR. SANTOS: Currently ...

this But imagine how

intervene to resolve this

remedial measures are not

MR. LEON ORTIZ: health professionals and For

example, with students. A community, a population, there is a

school, there is a hospital, there is a police station, and all

the south area of town eh Bordaleza. In other words,

there is a whole community The parks eh therefore,

eh Imagine the importance of this for us uh. . . And I

thank you very much eh that the agency has been

concerned and continues to investigate ...

MR.SANTOS: Yes

MR.LEON ORTIZ: and we are ready to collaborate on

everything we can. But for example, look, we regularly meet on

Mondays at the Cultural Center of Maunabo. There we can analyze

which is our public forum. The Jueyero Festival ends on

September 1st. In these four days eh I could ... Unless

you want to hand out flyers)) right?)) At the festival or give a

message to the community, somehow. You can even use eh

R2-0002762

37

the stage. Us, we have Saturday afternoon, we could provide you

the ... eh before a show of bomba and plena, to give a spech

and bring this issue to the community and ... Because people are

alarmed and I think they are scared too, but they still have not

understood the problem and the solutions I think. Unless

eh ... I, I'm the one that's lost and the whole world knows that

the thing is under control and then I should not be so concerned

eh ... Well, I thank you, Mr. Santos, for this information.

I basically asked all the doubts I had. The other question I

have is if you do not need measures from health professionals

eh emergency eh to guide the community eh

about the water ... eh ... drinking, filtering, eh if

it is necessary to process it, if it is reliable and more,

eh that can, in this festival we can. . . Because this gets

full, maybe we can give them the information and remove public

concern about there being a crisis eh of emergency in

the Maunabo underground wells.

MR.SANTOS: At this point, I would not use those words,

emergency crisis. What I would say is that the Wells the

four wells used by the Authority to serve water to the people

are fit for consumption.

MR.LEON ORTIZ: That is very important. That is very

important ...

MR. SANTOS: I would say it is suitable ...

MR.LEON ORTIZ: the people ...

MR.SANTOS: because ...

R2-0002763

38

MR.LEON ORTIZ: ... I know, I know ...

MR.SANTOS: substances found have not reached the

wells yet. Therefore, these substances are remote and and

the remedy we are proposing is to dissipate this pollution

is so it never reaches the drinking water well.

MR. LEON ORTIZ: Alright. And ...

MR. SANTOS: Currently, there lS no problem, based on

the results of our analysis.

MR.LEON ORTIZ: But I, as I read, it said that you did

some tests on some ... eh ... Public faucets ... eh ... and that

there were some margins that were a concern of contamination. I

do not know which area was ... this ... I worry if that is still

done.

MR.SANTOS: No, no ...

MR.LEON ORTIZ: If it is not like that ...

MR. SANTOS: in our study ...

MR. LEON ORTIZ: No?

MR. SANTOS: No.

MR. LEON ORTIZ: No? Ah, well ...

MR. SANTOS: We studied the ... the well and the faucet

well. We took samples at the well of of PRASA and

adjacent to the well faucet, before and after processing, in the

case that there is treatment. And both. . . eh

fit for consumption.

samples were

MR.LEON ORTIZ: For consumption. Oh, what a joy.

R2-0002764

39

MR.SANTOS: So, it is working.

MR.LEON ORTIZ: What a joy. So, would that be so,

basically ...

MR.SANTOS: That does not mean ...

MR.LEON ORTIZ: permanent?

MR.SANTOS: you may have a specific flavor, because

each area of the island has different flavors.

MR. LEON ORTIZ: Yes, yes, yes, yes, yes, yes.

say that whoever drinks water from there, from La Pica,

town. Each region has the ...

MR. SANTOS: Its own taste ...

MR.LEON ORTIZ: That management ...

MR.SANTOS: different.

MR.LEON ORTIZ: particular ...

MR. SANTOS: That is not within the setting ...

Here

stays

we

in

MR. LEON ORTIZ: It is a blessing)) right?)) That water

is so necessary.

MR.SANTOS: Mhm.

MR.LEON ORTIZ: So, about your body and how we protect

it.

MR.SANTOS: Mhm.

MR.LEON ORTIZ: Well look, I think ... I'm so glad the

waters are safe, it is great that there is a remedial plan

R2-0002765

40

this I think, then, that there is a social concern, which

can be made clear by using the newspaper, a meeting, as

discussed right now, that we can do to make more public

awareness, if possible, which is to help us become more aware,

as citizens, on our natural resources and how we care for,

protect and ... and we participate in the effort for that to be

that way, see? That is my concern.

MR.SANTOS: Well, thank you for your participation. It

Has been well . . . eh good.

MR.LEON ORTIZ: Well, if I've served some purpose,

then ...

MR.SANTOS: Yes, thank you.

MR.LEON ORTIZ: I'm glad.

MR.SANTOS: Thanks.

MR.LEON ORTIZ: And if there is any information you can

bring during the Festival, well, I, from the Cultural Center, I

can make arrangements. The Cultural Center is that building that

next to this one ...

MR.SANTOS: Mhm.

MR.LEON ORTIZ: we organize the artisans and others

and there is an exhibition ...

MR. SANTOS: I understand that, right now, that gives ...

that information we brought ...

MR.LEON ORTIZ: Yes

MR. SANTOS: you can take it, at least, the one

R2-0002766

that's in Spanish ...


MR.SANTOS: so you can .. .

MR.LEON ORTIZ: No and some .. .

MR. SANTOS: distribute it, because it is ...

MR.LEON ORTIZ: in English. And some ...

MR.SANTOS: And you can take as many as you like.

MR.LEON ORTIZ: Yes, that ...

MR.SANTOS: It's yours.

MR.LEON ORTIZ: ... would ...

41

MR. SANTOS: The flyers are yours, because we're going

to use you ...

MR.LEON ORTIZ: Yes, because ...

MR. SANTOS: as a spokesperson ...


MR. SANTOS: of us, as part of the Community.

MR. LEON ORTIZ: and ...

MR.SANTOS: We've already adopted you. Now you are one

of us and we'll help you. You're in the team.

MR. LEON ORTIZ: Well, I'm available, I am retired

this ...

MR.SANTOS: Well, do not worry, because ...

R2-0002767

42

MR.LEON ORTIZ: Yes

UNIDENTIFIED VOICE: You have work.

MR. SANTOS: We're going to leave the information and

I' 11 get in touch with you between Monday and Tuesday to tell

you which day would be the most convenient day for us to come

again.

MR. LEON ORTIZ: Okay . . . eh . . . And I, in all. . . I' 11

try to do everything I can during the Jueyero Festival ...

MR.SANTOS: Very well.

MR.LEON ORTIZ: that is an opportunity where I get

to see a lot of people from the town ...

MR.SANTOS: distribute them, because ...

MR.LEON ORTIZ: ... and ...

MR.SANTOS: there you will see information and ...

MR.LEON ORTIZ: Yes

MR.SANTOS: people who are interested and can form

a group and talk about it the day ...


MR.SANTOS: ... well, you tell me what day you want me to come.

MR. LEON ORTIZ:

... I agree with that

Yes, yes.

this

if there is something else ...

MR.SANTOS: No, because ...

Yes, yes, of course. . . . this

Well, I ... eh ... don't know

MR.LEON ORTIZ: Are we good?

R2-0002768

43

MR. TORRES: And I want to mention something. This is Ramon

Torres, from the

Alternative Number

analysis, the

EPA. And the final decision about the

3 for remediation, all this information,

a summary of the risk analysis, the

of why we came to that decision, why we

all that will be captured in a document called a

explanation

recommend that,

record of decision.

MR.LEON ORTIZ: OK.

MR. TORRES: OK? The record of decision is

of reading all the ... the range ... of ...

MR.LEON ORTIZ: Studies and others?

instead

MR.TORRES: technical studies that may not be

understood) ) right?) ) , no offense to anyone, but is much

very complicated ...

MR.LEON ORTIZ: Yes, yes, yes.

MR.TORRES: eh ... we prepare a record of decision,

which explains all the alternatives, explains analysis of why we

chose this versus the other three and, then, well, that also

will be available once we finish the ... the comments period ...

On September 7 ...

MR.LEON ORTIZ: Yes

MR.TORRES: and it includes everything the

answers to all the questions that you just made, will be written

in a document called "responsiveness summary", where we will

collect all comments, both written as verbal and answer them ...

in the document. Well, that document has three parts, it has a

"statement" of authorization, the record of decision, which is

the explanation of everything and the last part is the reply to

R2-0002769

44

all comments. And that, once eh ... is signed, it is a legal

document ... eh ... and it's therefore states what was done. And

this document once is final, it will be available to the public,

so, then, what you have and can say, "Hey, what happened here?

You said "

MR.LEON ORTIZ: Yes

MR. TORRES: II you were going to do this. What

happened?"

MR.LEON ORTIZ: OK.

MR.TORRES: OK?


MR.TORRES: That's to let you know that too ...

MR.LEON ORTIZ: Well, for me, particularly )) Right?)),

If there is no alarm,

community to take health

eh if there is

measures, for the

no need for the

students to be

informed in the correct use of the water or the place, because

of skin and all of that... If the death cases that have been

reported in some areas are not related to - or if some of them

are, well I would like to know the amount) ) right?) ) --because

the study does not tell me how many people of Maunabo are

undergoing treatment, and that lS a doubt I have)) right?))

concerning Because some people say that in Maunabo there

have been many cases of cancer; skin cancer... Many cases of

kidney diseases, many people, including some friends of mine

having dialysis and other problems and eh People have

gotten scared to go in the river and go to ... the mouth of the

river, there, to the beach, which is the closest to this area of

pollution ... this ...

R2-0002770

45

Well, eh ... if there is no health concern and nothing

to worry about then we can start giving this information to do

the institutions here in Maunabo, eh schools, churches

and others, a simple fact sheet can be prepared about this, ...

eh ... so they can get informed about the findings and the job

that is being done on water quality in Maunabo, the problem of

groundwater eh and eh processes being carried

out to eh ... articulate, try to solve the problem, right?

That ... this is resolved in a satisfactory manner.

MR. TORRES: Yes, no problem. I want you to understand

it does not end here. In other words, does not end ... we do not

finish with a record of decision. After that the design process

begins and the action to take, EPA will be here for a long time.

MR.LEON ORTIZ: Ah well.

MR.TORRES: So, this is not going to end it, with this,

it won't be all over. No. Now comes the second stage.

MR.LEON ORTIZ: That is very important.

MR.TORRES: So, is that no ...

MR.LEON ORTIZ: They're ...

MR. TORRES: in the process in the process of

Superfund ...

MR.LEON ORTIZ: Design ...

MR.TORRES: this is the record of decision, that's

the one I told you about, the legal document ...

MR.LEON ORTIZ: Yes

R2-0002771

operation

still has

leaving ...

MR. TORRES: see ...

and maintenance will

a lot of work here.

MR.LEON ORTIZ: Yes

46

then, the design and action and

continue. Which means that EPA

What I mean lS that we're not

MR.TORRES: this neither the Board nor. We are

prisoners here with you, with this beautiful place I say

prisoners ...

MR.LEON ORTIZ: Yes

MR. TORRES: in the sense that we are committed

here, so, which is fine. And we will be working on that. And the

and community involvement continues. In other words, it

does not stop here.

We ended This is one stage. We return. These are the

stages. We ended this stage, but we then follow the second. When

we explain There must be other public meetings to discuss

how the design is going, how it will be implemented, etc., etc.,

etc. and you can continue this that effort within the

Community Involvement plan that we have, which is done for

for that matter, to continue ... eh in ... and informing the

community about what is happening in the project, because it is

important.

MR.LEON ORTIZ: And you continue to receive information from

the Department of Health on cases and situations or treatment?

Or that area would be more ...

MR.TORRES: That area ...

MR.LEON ORTIZ: ... research?

R2-0002772

47

MR. TORRES: That area is an epidemiology study and we

do not work with the area of epidemiology ... this That is

the Department of Health. They're the ones that do all the

studies and statistics.


MR.TORRES: What we mostly work on is the environmental

area, the contaminants. And what we are trying to avoid is for

them to have to do an epidemiology study ...


MR. TORRES:

problem is there ...

because if they do, that means that the


MR.TORRES: So, we are trying to prevent this problem.

are now,


MR.TORRES: Right

I can clearly

now,

tell

clearly,

you that

sediments and soil are not polluted. There

... plumes were found down there that

these

the

findings which

surface water,

there are . . . eh

those plumes they

call, those are the ones we will wor "address", ... to work

them, for the simple reason that they can pose a danger to human

health and the environment before it reaches the wells

especially to human health before it reaches PRASA wells, we

will correct them. And that's whal we're trying to do.

MR.LEON ORTIZ: Good.

MR.TORRES: OK?

MR.LEON ORTIZ: Good.

R2-0002773

48

MR.TORRES: Well, thank you all for being here. So,

with this, then we finished, so we're going keep in touch with

Luis to arrange all of this, OK? Well then the meeting is

finished. Thank you for your participation.

MR.LEON ORTIZ: Well, thank you.

(The proceedings are concluded)

****************

R2-0002774

49

CERTIFICATE OF REPORTER

I, Ricardo Alvarado, E.R. Reporter, Reporters FASYO member,

CERTIFY:

That the above ls a true and correct transcript of the

recording made during the meeting held at the place and date

indicated on page one of this transcript.

I further certify that I have no interest in the outcome of

this matter and I have no relationship to any degree of

consanguinity with the parties involved in it.

In San Juan, Puerto Rico, September 4 2012.

RICARDO ALVARADO E.R. Reporter

****************

Translated by:

Aledawi Figueroa www.smileagainpr.com (787) 872-5151 I (787) 225 6332

R2-0002775

MARTINEZ ODELL & CALABRIA

P.O. BOX 190998

SAN .JUAN, PUERTO RICO 00919·0998

TELEPHONE (787) 753-8914

TELEFAX (787) 753-8402

www.mocpr.com

.JORGE .J. GARCiA-DiAZ BANCO POPULAR CENTER

PARTNER SIXTEENTH FLOOR

(787) 274-2912 SAN .JUAN, PUERTO RICO 00918

[email protected]

Via Certified Mail Return Receipt and E-Mail at [email protected]

Luis E. Santos Remedial Project Manager

September 7, 2012

United States Environmental Protection Agency Caribbean Environmental Protection Division City View Plaza II- Suite 7000 48 RD. 165 KM 1.2 Guaynabo, Puerto Rico 00968

Re: Maunabo Groundwater Contamination Superfund Site, Maunabo, Puerto Rico

Dear Mr. Santos:

The comments contained in this letter are submitted to the U.S. Environmental Protection Agency ("EPA") on behalf of the Puerto Rico Industrial Development Company ("PRIDCO"), regarding the Proposed Plan (the "Plan") prepared by EPA which identifies EPA's Preferred Alternative for cleaning up the groundwater at the Maunabo Groundwater Contamination Superfund Site (the "Site"). The comments follow the Public Hearing held by EPA on August 29, 2012 in Maunabo. They are timely submitted within the Public Comment Period which ends on September 7, 2012 and requires that they be postmarked on or before said date.

PRIDCO has reviewed the Plan and its representatives have gathered information concerning the Site and areas in the vicinity of the Site since 2005. PRIDCO had also submitted comments to EPA on June 19, 2006 regarding the proposed listing of the Site on the National Priorities List and the reasons why it believed and still believes that it should not be considered as a potentially responsible party ("PRP").

The information upon which PRIDCO supports its determination that it is not a PRP for the Site includes the following:

• PRIDCO was established as a public corporation and a governmental instrumentality of the Commonwealth of Puerto Rico for the purpose of promoting the development of the economy of Puerto Rico by stimulating the formation of new local firms and encouraging firms in the United States and foreign countries to establish and expand operations in Puerto Rico. To accomplish its mission, PRIDCO maintains a continuing infrastructure development program, including facilities for lease or sale to qualified private

R2-0002776


Luis E. Santos Remedial Project Manager September 7, 2012 Page 2 of?

4555726.1

industrial and commercial investors, and the construction of industrial and commercial facilities for lease. In addition, PRIDCO disburses legislative appropriations in accordance with various special incentives programs to assist manufacturers in offsetting allowable start-up costs. The basic purpose underlying PRIDCO's supporting role to Puerto Rico's economic development program is the creation of jobs and the consequent improvement of living standards in Puerto Rico. In order to conduct its legislatively-created authority, PRIDCO has the power, among other things, to acquire, own, sell and lease property, all for the purpose of assisting and enhancing Puerto Rico's economy.

• PRIDCO does not operate any facility. PRIDCO only owns the land and constructs the buildings to be used by its tenants. As a result, PRIDCO does not generate any hazardous substances or hazardous wastes. As noted above, it is simply a passive landowner, which leases property it owns to commercial and industrial entities for economic development purposes, and takes measures to ensure its tenants comply with all applicable laws, regulations and best practices to protect the environment.

• PRIDCO's environmental consultant, Caribe Environmental Services, Inc. ("CES"), has evaluated the Plan, reports and data, including those available from EPA and the Puerto Rico Environmental Quality Board, and has visited the Site and areas in the vicinity of the Site. In addition to the EPA's HRS Documentation Record, CES has reviewed, among other documents, EPA's Preliminary Assessment Inspection Report, Maunabo Urbano Municipal Wells, Volumes I, II and Ill, March 2006.

Based upon the CES' evaluation, the following conclusions can be drawn:

o The data available to CES for the five industrial facilities referenced in the Plan does not indicate the historical use by any of PRIDCO's tenants, past or present, of the chlorinated solvents or their degradation products that have been detected in the public wells which constitute the Site. Furthermore, the available data presented in the Plan does not identify any of PRIDCO's properties as the source of contamination. In addition to PRIDCO's belief that it should not be considered as a PRP for the Site based on the evaluation of its own file records, PRIDCO also supports its reasoning based on EPA's conclusions in the Plan as further described below:

R2-0002777


Luis E. Santos Remedial Project Manager September 7, 2012 Page 3 of7

4555726.1

1. Centro Acopio Manufacturing

PRIDCO's review of its files for this site does not indicate the historical use of chlorinated solvents by any of the tenants that occupied the building. PRIDCO's Environmental Division conducted inspections of the site when Sunoco, NPFW and Coop. Industrial Mercadeo Agrimax were tenants and did not identify any issues of environmental concern during the inspections. The information available at PRIDCO does not indicate the presence of chemical storage areas, above ground tanks, underground storage tanks or underground injection units. The available information indicates that the tenants at this facility did not generate any hazardous wastes or used chlorinated solvents.

The Plan indicates that EPA collected four surface soil samples, two subsurface soil samples and one groundwater sample from open areas adjacent to the Centro Acopio Manufacturing (CAM) facility. EPA's results indicated that no VOCs were detected in the soil and groundwater samples. EPA also indicated that a review of available background information revealed that these substances were not generated by activities at the CAM facility, nor were any waste sources suspected of releasing or having the potential to release contaminants to groundwater or surface water identified at the CAM facility. The PAISI report prepared by EPA recommended no further remedial action for the CAM facility.

EPA's conclusion of no further remedial action is consistent with the available information that PRIDCO has for this site.

2. Juan Orozco Limited, Inc.

PRIDCO's review of its files available for this site does not indicate the historical use of chlorinated solvents by any of the tenants that occupied the building. PRIDCO's Environmental Division conducted inspections of the site when Fiterteck and Juan Orozco Limited were tenants of the building and did not identify any issues of environmental concern. The available information does not indicate the presence of chemical storage areas, above ground tanks, underground storage tanks or underground injection units. The available information indicates that the tenants at this facility did not generate any hazardous wastes or used chlorinated solvents.

The Plan indicates that EPA collected four surface soil samples, two subsurface soil samples, and one groundwater sample from open areas adjacent to this site. Analytical results indicated non-detect values for

R2-0002778


Luis E. Santos Remedial Project Manager September 7, 2012 Page 4 of 7

4555726.1

contaminants previously detected in the Maunabo public water supply wells as well as the remaining VOC parameters. EPA stated that a review of available background information indicated that these substances were not generated by activities at Juan Orozco Limited, nor were any waste sources suspected of releasing or having the potential to release contaminants to groundwater or surface water identified at the facility. The PAIS! report prepared by EPA recommended no further remedial action.


3. Puerto Rico Beverage

PRIDCO's review of its files available for this site does not indicate the historical use of chlorinated solvents by any of the tenants that occupied the building.

EPA collected four surface soil samples, two subsurface soil samples and one groundwater sample from open areas adjacent to the Puerto Rico Beverage (PRB) facility building. The EPA data indicated that no VOCs were detected in the samples. EPA stated that a review of available background information indicated that VOCs were not generated by activities at PRB, nor were any waste sources suspected of releasing or having the potential to release to groundwater or surface water identified at the PRB facility. The PAIS! report recommended no further remedial action for PRB.


4. FEMA Storage Facility

PRIDCO's review of its files available for this site does not indicate the historical use by its former tenants of the chlorinated solvents that were the target of the EPA investigation.

According to the Plan, EPA collected five surface soil samples, including a duplicate sample and two subsurface soil samples from open areas adjacent to the FEMA Storage Facility. EPA's sampling results revealed that no VOCs were detected in the samples.

EPA's information and sampling results are consistent with the available information that PRIDCO has for this site.

R2-0002779



4555726.1

5. Plastic Home Products

PRIDCO's review of its files available for this site does not indicate the historical use of chlorinated solvents by its former tenants. PRIDCO's Environmental Division conducted inspections of the site when FEMA and Muebles Eirico were tenants of the building and did not identify any issues of environmental concern. The available information does not indicate the presence of chemical storage areas, above ground storage tanks, underground storage tanks or underground injection units at the site.

EPA collected four surface soil samples and two subsurface soil samples from open areas adjacent to the Plastic Home Products (PHP) site. EPA's sampling results revealed that no VOCs were detected in the samples. EPA further stated in the Plan that a review of available background information indicated that VOCs were not generated by activities at PHP, nor were any waste sources suspected of releasing or having the potential to release contaminants to groundwater or surface water identified at the PHP site. The PAIS! report recommended no further remedial action for PHP.


o On page 4 of the Plan EPA states that the cis-1 ,2-DCE Plume indicates that a release of site-related contaminants, most likely PCE or TCE, occurred in or near the Puerto Rico Beverage (PRB) facility. However, PRIDCO respectfully understands that the information presented in the Plan is not sufficient to reach the conclusion that a release of PCE or TCE occurred in or near the PRB facility. We note, in support of our understanding, that according to the Plan, the highest concentrations of cis-1 ,2-DCE detected are outside of the PRB site. Also, as stated by EPA in the Plan, no detection of VOCs was reported on soil and groundwater samples collected at the PRB site, despite that EPA initially identified this site as a potential source based on its groundwater screening results. Also, of particular relevance in supporting PRIDCO's position herein is that none of the six related VOCs were detected in soil samples at the PRB site during EPA's additional investigation activities. Considering the fact that chlorinated solvents are known to be sinkers, it is expected that they will sink underneath the potential point of release in the soil and groundwater underlying the area of the release. Therefore, it would be expected that the highest concentrations of this substance be located at

R2-0002780



4555726.1

the potential source area and not outside said area, as it appears from the Plan.

o As noted above and as previously commented by PRIDCO to EPA in its letter of 2006 in the instant matter, PRIDCO's review of its own file records, and where relevant, site visits reveal that the tenants which currently occupy the PRIDCO-owned buildings in the vicinity of the Site have not used the chlorinated solvents that have been detected in the Site wells. Furthermore and most notably, EPA's own investigation and results summarized in the Plan is consistent with PRIDCO's own investigation and does not identify a source of contamination coming from any of PRIDCO's properties at the Site. In addition and in support of the foregoing, from a calculation of the groundwater flow velocity, using data developed by the U.S. Geological Survey for the Maunabo Valley area, it is likely that the detected contamination is not associated with releases from former occupants of these properties either. Consequently, PRIDCO understands that the Plan supports PRIDCO's position that it should not be named as a PRP at the Site.

o PRIDCO's technical opinion is that a more likely source of chlorinated solvents at the area where the cis-1 ,2-DCE plume is shown in Figure 3 of the Plan would be the Maunabo Dry Cleaners facility located up gradient of the Maunabo Well #1. Dry cleaning facilities have been historically recognized as likely sources of PCE contamination. The volatile organic compounds detected at the Maunabo #1 well, except for MTBE, are all associated with PCE. The main degradation products of PCE are TCE, cis DCE, 1,1 DCE, trans DCE and vinyl chloride. Based upon the groundwater flow direction at the site, it is likely that potential PCE releases at the dry cleaning facilities may have reached the Maunabo #1 Well. PRIDCO's property is, therefore, likely to be a "victim" of off-site passive migration of contamination as opposed to one of its properties actually being a source. It is not evident from the Plan and from the Siterelated information which CES has studied that this potential source in the vicinity of the Site has been properly investigated by EPA. It is respectfully suggested that such a step may be appropriate. In this regard, PRIDCO would like to meet immediately with EPA to present its information on the dry cleaners being likely the source rather than PRB.

Regarding the likeliness of cis-1 ,2-DCE plume coming from dry cleaning facilities up gradient of the Maunabo Well #1, PRIDCO respectfully suggest to EPA that it modifies the current language in the first sentence of the cis-1 ,2-DCE paragraph in page 4 of the Plan, followed by a new sentence to read as follows: "Cis-1,2-DCE Plume - The configuration of

R2-0002781


Luis E. Santos Remedial Project Manager September 7, 2012 Page 7 of?

this plume indicates that a release of off-site-related contaminants, most likely PCE or TCE, occurred up gradient of Maunabo Well #1, potentially from dry cleaning operations. Therefore, further investigation is necessary to determine where the release is coming from" . ...

In summary, what seems clear at this juncture, based on the foregoing and on the other information reviewed by CES, is that the facilities on the PRIDCO-owned properties in Maunabo do not constitute a source of the contamination of the Site wells. Consequently, PRIDCO respectfully states that: (i) it should not be considered as a PRP for the Site; and (ii) EPA should consider investigating other potential sources of contamination such as dry cleaners up gradient from the Site.

As stated above, PRIDCO is willing and able to meet immediately with EPA to present its information on the dry cleaners being likely the source of the cis-1 ,2-DCE plume rather than the PRB site. PRIDCO understands EPA's desire to release the Record of Decision of the Site by September 30, 2012 and its intention to meet with EPA in no way should be considered as an impediment or delay of said date, rather PRIDCO is willing to move with EPA quickly in order to meet the current timeline proposed by the agency.

PRIDCO appreciates having the opportunity to provide these comments to EPA.

Sincerely,

9,,~G,9 ?·

4555726.1

R2-0002782

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 2

PART III – RESPONSIVENNES SUMMARY

RECORD OF DECISION MAUNABO GROUNWATER CONTAMINATION SUPERFUND SITE


R2-0002783

1

RESPONSES TO PUBLIC COMMENTS PREPARED IN SUPPORT OF THE RESPONSIVENESS SUMMARY FOR THE

RECORD OF DECISION MAUNABO GROUNDWATER CONTAMINATION SUPERFUND SITE


On August 9, 2012, the U.S. Environmental Protection Agency (EPA) released for public comment the Proposed Plan for the Maunabo Groundwater Contamination Superfund Site (Site). During the public comment period, EPA held a public meeting on August 29, 2012 to discuss and accept comments regarding the Proposed Plan. EPA received verbal comments at the public meeting as well as written comments during the public comment period. EPA also held a public availability session at the Maunabo Public Library on September 5, 2012 to discuss the preferred remedial alternative. This document summarizes comments from the public at the public meeting on August 29, 2012 and those submitted via mail. EPA’s responses are provided following each comment. The comments are group generally in the following categories: Community Involvement Background Information Results Alternative 3 Potential Sources Health Risks Community Involvement Comment 1: It seems there is a problem with the community involvement program. I am the only resident here and for this public meeting not to be a formality, I request that a new invitation be made with more emphasis to the community. Response 1: EPA had published public notices on two occasions in El Nuevo Día and La Esquina newspapers to advertise the public meetings. The first public meeting scheduled had to be cancelled due to Tropical Storm Isaac. Fact sheets have also been made available to the public. In addition to your presence, a representative from the Puerto Rico Development Company (PRIDCO) is present. EPA will continue with the public meeting presentation as scheduled and will respond to concerns. EPA will add a public availability session so the community will have an additional opportunity to raise concerns. The community has until September 7th to submit written comments to EPA. Comment 2: It is good that the water is safe for consumption and that there is a remediation plan. But I believe that there is a social concern which could be alleviated by using La Esquina newspaper or public meetings. If provided with information, I will distribute it in the upcoming festival. Response 2: EPA will appreciate your assistance with the distribution of the provided fact sheets and sharing the date for the public availability session. EPA will also communicate with you to coordinate the public availability session. EPA will capture comments, concerns, risk analysis, and information from residents about the selected alternative in the Record of Decision. Additionally, the Responsiveness

R2-0002784

2

Summary document will contain the responses to questions and concerns. These documents will be made public. Background Information Comment 1: The public supply wells provide water to all Maunabo? Including the flat lands? Response 1: The public supply well system, consisting of wells Maunabo 1, 2, 3 and 4, supplies the urban areas and nearby wards, including the flat lands. Comment 2: Are well 1 and well 4 the ones with the highest concentration of contaminants? The analysis performed by the health department or EPA demonstrated that the water is suitable for consumption? In 2000? Response 2: The Puerto Rico Department of Health regulates the public water supply services Puerto Rico Aqueduct and Sewer Authority (PRASA) provides to the public. The Department of Health uses the federal standards for evaluating drinking water. Every substance listed in the federal standards that exceeds the permissible limits does not comply with federal standards for drinking water. As such, once detected, the Department of Health prohibits the use of the water for consumption. That is what happened in 2002; the Public Supply Well 1 did not comply with the federal standards. The Department of Health ordered PRASA to close the well 1; PRASA opted to treat the groundwater which allowed continued use of the water. Comment 3: Was the treatment effective? Response 3: Yes, it was effective. That was the reason the Department of Health allowed [PRASA] to continue providing water from this well. Comment 4: So it was considered an emergency and was attended to? Response 4: As a result of the exceedance of the drinking water standards, EPA conducted a preliminary investigation in 2004 and a site investigation in 2005 that resulted in the listing of the site on the National Priorities List in 2006. Comment 5: I read that analyzed tap water samples, at locations that I don’t know, showed contaminants at levels of concern. I am worried that it is still a concern. Response 5: As part of this investigation EPA collected samples before and after treatment at the well and the results showed that water is safe for consumption.

Results Comment 1: What are the areas of possible sources of contamination?

R2-0002785

3

Response 1: EPA conducted a preliminary investigation at five areas that were identified as potential sources of contamination. After this investigation, three areas remained as potential sources of contamination. Sixteen monitoring wells were installed in these areas. The sampling network included monitoring wells and four PRASA public supply wells, for a total of 20 wells. Comment 2: Was the sampling performed specifically in the areas you mentioned or does it include the river? Response 2: EPA collected samples along the river upgradient and downgradient from the potential sources of investigation. Comment 3: So, the land is suitable for agricultural use? Response 3: EPA sampled soil in all screening areas - which practically covered the entire town - and the results showed that they presented no human risk. Alternative 3 Comment 1: When sparging, where will the air go out? Response 1: The air injected to the subsurface will come out to the surface through the soil vapor extraction system that is part of the overall remedy. Comment 2: Is the air coming out of wells contaminated or has it been attenuated? What about skin problems, direct contact, or respiration? Response 2: It will be attenuated. Since the concentrations in groundwater are low, the air collected by the soil vapor extraction system would be very low and potentially below detection limits. The concentrations will range in parts per billion which are very low and nearly undetectable. The levels will have no effect on human health or the environment. Comment 3: How long, more or less, will the remediation take? Will it be performed in one round? What is a round? Response 3: The duration of the remediation process will be dependent on the monitoring results. As progress is monitored EPA will be know the effectiveness of the system and when the remediation goals are met. Each round of results will be evaluated and provide comparison information to evaluate the time needed for implementation. The remediation process can last approximately 30 years. Comment 4: Your design is based on the assumption that the source of contamination is under control and it does not exist anymore? Response 4: EPA did not identify specific sources of contamination but rather areas where contamination may have been input into the aquifer. However, after two rounds of sampling, the results showed a

R2-0002786

4

reduction in the concentration of contaminants in the groundwater in comparison to previous sampling events, indicating that the source of contamination is probably no longer active. Potential Sources Comment 1: I have analyzed the situation and believe that mismanagement of PRASA’s wastewater treatment plant as a source of contamination, and later updating may have cause the cessation of the contamination. Response 1: Based on the fact that the PRASA plant processes wastewater and that the contaminants found are industrial in origin, EPA does not believe there is a connection. Comment 2: We suspect that the other potential source could be the landfill established in Tumba’o Ward. The construction of the landfill coincided with the closing of Union Carbide in Yabucoa. Although the landfill was lined, the information we have is that toxic substances were dumped there and also contained contaminants from Roosevelt Roads base. We have no documentation to prove this information because no records were kept. An investigation will be needed. Response 2: EPA is open to information provided by the community that could help identify sources of contamination and potential responsible parties. All information provided will be analyzed and, if necessary, EPA will perform an investigation. Comment 3: PRIDCO provided comments that it is its technical opinion that a more likely source of chlorinated solvents at the area where the cis-1,2-DCE plume is shown in Figure 3 of the Plan would be the Maunabo Dry Cleaners facility located upgradient of the Maunabo Well #1. PRIDCO points out those dry cleaning facilities have been historically recognized as likely sources of PCE contamination. The volatile organic compounds detected at the Maunabo #1 well, except for MTBE, are all associated with PCE. The main degradation products of PCE are TCE, cis DCE,1,1 DCE, trans DCE and vinyl chloride. Based upon the groundwater flow direction at the Site, PRIDCO indicated that it believes that it is likely that potential PCE releases at the dry cleaning facilities may have reached the Maunabo #1 Well. PRIDCO's property is, therefore, it believes, likely to be a "victim" of off-site passive migration of contamination as opposed to one of its properties actually being a source. It is not evident to PRIDCO from the Proposed Plan and from the Site related information which PRIDCO’s consultant has studied that this potential source in the vicinity of the Site has been properly investigated by EPA. It suggested that such a step may be appropriate and that language in the Proposed Plan be modified to reflect its position that the Dry Cleaner is the likely source of contamination. PRIDCO concluded at this juncture, based on the foregoing and on the other information reviewed by PRIDCO’s consultant, it believes that the facilities on its properties in Maunabo do not constitute a source of the contamination of the Site wells. Response 3: Groundwater Screening Transect Number 2, as shown on Figures 2-1 and 4-6 (Figure Inset) of the Maunabo Groundwater Contamination Site Final Remedial Investigation (RI) Report (June 29, 2012) was located to intercept any groundwater contamination downgradient of the Maunabo Dry

R2-0002787

5

Cleaners. Six groundwater screening locations were drilled along Transect Number 2. Groundwater screening samples were generally collected at the refusal depth and every ten feet until the top of the water table. No water was encountered in the two locations on the transect’s west side (T2-A and T2-AA) because shallow bedrock was encountered. At T2-B, only one sample was collected at 19 feet below ground surface (bgs). At T2-C, D, and E samples were collected at approximately 30 feet bgs, 20 feet bgs, and 10 feet bgs. No site related contaminants (tetrachloroethene (PCE), trichloroethene (TCE), cis-1,2-dichloroethene (DCE), 1,1-DCE, trans-1,2-DCE, and vinyl chloride) were detected in groundwater screening samples in this transect. If a release of PCE or TCE occurred from the dry cleaners, remnant PCE/TCE or breakdown products would be expected to be detected in the groundwater screening samples. Because no site-related contaminants were detected in the 10 groundwater screening samples collected along Transect Number 2, no further investigation of this area was completed for the RI, and we cannot conclude that the Dry Cleaner is a source of contamination. No site related contaminants were detected in Groundwater Screening Transect Number 3, which was located to intercept any possible groundwater contamination downgradient of the Plastic Home Products Facility and the Federal Emergency Management Agency (FEMA) Storage Facility. If a release of PCE or TCE occurred from these facilities, remnant PCE/TCE or breakdown products would be expected to be detected in the groundwater screening samples. No further investigation of this area was conducted in the RI. Site related contaminants, especially cis-1,2-DCE, vinyl chloride, PCE, and TCE, were detected in the portion of Transect 1 downgradient of the Puerto Rico Beverage (PRB) property. Two locations, T1-N and T1-L, were on the PRB property and T1-C was 40 feet downgradient of the property. Monitoring well MW-B was installed at the T1-C location. The Federal Maximum Contaminant Level (MCL) for cis-1,2-DCE is 70 micrograms per liter (µg/L). The highest concentration of cis-1,2-DCE at these locations were: T1-N – 60 µg/L (58-62 feet bgs) T1-L – 19 µg/L (19-23 feet bgs) T1-C – 200 µg/L (36-40 feet bgs) MW-B – 300 µg/L (25-35 feet bgs)

Cis-1,2 DCE and vinyl chloride, breakdown products of PCE and TCE, were generally detected in the shallow and intermediate groundwater screening intervals while PCE and TCE were detected in the deepest intervals. Vinyl Chloride, PCE, and TCE were not detected above MCLs in any of these samples. No site related contaminants were detected at the following locations: Groundwater screening location T1-K, upgradient of the northeast boundary of the PRB property Groundwater screening location, GS-D, upgradient and north of the PRB property Monitoring well MW-D upgradient and north of the PRB property.

Because site related contamination was detected in the groundwater on the PRB property and immediately downgradient of the PRB property, six soil borings were sampled to a depth of 12 feet below the ground surface. No site related contaminants were detected in the soil samples collected. Therefore, the source of the site-related chlorinated VOCs in the groundwater samples is uncertain. However, based on the

R2-0002788

6

groundwater screening results for Transect Number 2, the dry cleaner cited in the comment is likely not the source of the groundwater contamination. Health Risks Comment 1: Does EPA receive information from the Department of Health on cases or treatments? Response 1: EPA’s investigations are principally in the environmental field. Based on the results of this investigation, the surface water, sediments, and soils do not contain the contaminants of concern at levels that may represent risks to human health or the environment. The groundwater plumes will be treated before reaching PRASA’s wells.

R2-0002789

RECORD OF DECISION Maunabo Groundwater ...Contamination Site (the “Site”), located in the...

Documents

Transcript of RECORD OF DECISION Maunabo Groundwater ...Contamination Site (the “Site”), located in the...