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DRAFT FINAL PKEAK;REMEDIAL

VOLUME 1 OF 4 - TEXT

REMEDIAL INVESTIGATION/FEASIBILITY STUDY

NEW HAMPSHIRE PLATING COMPANYMERRIMACK, NEW HAMPSHIRE

ForU.S. Environmental Protection Agency

ByHalliburton NUS Corporation

andRaytheon Engineers & Constructors, Inc.

EPA Work Assignment No. 33-1LG1EPA Contract No. 68-W8-0117

HNUS Project No. 0772

May 1996

Halliburton NTJSC O R P O R A T I O N

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DRAFT FINAL REMEDIAL INVESTIGATION REPORT

VOLUME 1 OF 4 - TEXT

REMEDIAL INVESTIGATION/FEASIBILITY STUDY

NEW HAMPSHIRE PLATING COMPANY MERRIMACK, NEW HAMPSHIRE

For U.S. Environmental Protection Agency

By Halliburton NUS Corporation

and Raytheon Engineers & Constructors, Inc.

EPA Work Assignment No. 33-1LG1 EPA Contract No. 68-W8-0117

HNUS Project No. 0772

May 1996

Marilyn M. Wade, P.E. George D(7Gardner, P.E. Project Manager Program Manager

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E.O EXECUTIVE SUMMARY ES-1

1.0 INTRODUCTION 1-1 1.1 Site and Study Area Background 1-2 1.2 NHPC Site History 1-3 1.3 Report Organization 1-4

2.0 STUDY AREA INVESTIGATION 2-1 2.1 Previous Investigations 2-1

2.1.1 Peck Environmental Laboratory, Inc 2-1 2.1.2 Wehran Engineering 2-2 2.1.3 New Hampshire Department of Environmental

Services (NHDES) 2-3 2.1.4 Removal Action - U.S. EPA Emergency Response

Team (ERT) 2-4 2.1.5 Wetland Investigation 2-5 2.1.6 Technical Assistance Groundwater Sampling 2-6 2.1.7 Non-Time-Critical Removal Action 2-7 2.1.8 Previous Investigations on Properties

Abutting the NHPC Site 2-9 2.1.8.1 Magnum Leasing and Mortgage Company . . . 2-9 2.1.8.2 New England Pole and Wood Treating

Company 2-9 2.1.8.3 Techwood Building Systems, Inc 2-9 2.1.8.4 Jones Chemical, Inc 2-10

2.2 Study Areas Summary of Existing Information 2-11 2.2.1 NHPC Operations Area 2-11

2.2.1.1 NHPC Building Area 2-12 2.2.1.2 Former Lagoon Areas 2-13 2.2.1.3 Wetlands and Overflow Area 2-16 2.2.1.4 Other On-site Areas 2-17

2.2.2 Adjacent Properties 2-18 2.2.2.1 Magnum Leasing and Mortgage

Company Property 2-19 2.2.2.2 YMCA Property 2-19 2.2.2.3 Horseshoe Pond Island 2-20 2.2.2.4 New England Pole and Wood Treating

Corporation (NEPWTC) 2-20

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2.2.2.5 Lot Number 22 Property 2-21 2.2.2.6 Techwood Building Systems Property 2-21 2.2.2.7 Jones Chemical, Inc. Property 2-22

2.2.3 Other Locations of Investigation 2-23 2.2.3.1 Horseshoe Pond 2-24 2.2.3.2 Merrimack River 2-24

2.3 Conceptual Site Model 2-24 2.3.1 Source Areas 2-24 2.3.2 Migration Pathways 2-25

2.4 Objectives of the Rl 2-26 2.5 Summary of Remedial Investigation Activities 2-27

2.5.1 Phase I Activities 2-27 2.5.1.1 Surface Soil Sampling Program 2-28 2.5.1.2 Phase I Lagoon Sampling Program 2-29

2.5.2 Phase II Activities 2-31 2.5.2.1 Building Area Soil Boring Program 2-31 2.5.2.2 Lagoon Soil Boring Program 2-33 2.5.2.3 Monitoring Well Installation Program 2-40 2.5.2.4 Piezometer Installation 2-50 2.5.2.5 Soil Vapor Survey 2-50 2.5.2.6 Elevation and Location Surveys 2-51 2.5.2.7 Water Level Monitoring 2-53 2.5.2.8 Groundwater Sampling Program 2-54 2.5.2.9 Surface Water and Sediment Sampling

Program 2-55 2.5.3 Summary of Remedial Investigation Sampling

and Analysis 2-57 2.5.3.1 Data Quality and Data Quality

Objectives 2-57 2.6 Studies Performed By Others 2-58

2.6.1 Geophysical Studies Performed by United States Geologic Survey (USGS) 2-58

2.6.2 Ecological Studies 2-59 2.6.2.1 EPA Corvallis Laboratory 2-59 2.6.2.2 U.S. Fish and Wildlife Service 2-60

2.6.3 University of Cincinnati Stabilization/Solidification Studies 2-60

2.6.4 Former Building Soil Sampling 2-61

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3.0 PHYSICAL CHARACTERISTICS OF THE STUDY AREA 3-1 3.1 Surface and Topographic Features 3-1

3.1.1 NHPC Operations Area 3-1 3.1.2 Study Area 3-2

3.2 Demography and Land Use 3-3 3.2.1 Demography 3-3 3.2.2 Land Use 3-4 3.2.3 Groundwater Use 3-5 3.2.4 Surface Water Use 3-5

3.3 Climate 3-6 3.4 Surface Water Hydrology 3-7 3.5 Geology 3-8

3.5.1 Regional Geology 3-9 3.5.2 Study Area Geology 3-10

3.5.2.1 Unconsolidated Soil Deposits 3-10 3.5.2.2 Former Lagoon Areas 3-15 3.5.2.3 Bedrock 3-17

3.6 Hydrogeology 3-19 3.6.1 Shallow Overburden Aquifer 3-21

3.6.1.1 Hydraulic Conductivity 3-21 3.6.1.2 Groundwater Elevation Measurements 3-23 3.6.1.3 Horizontal Hydraulic Gradients 3-24 3.6.1.4 Horizontal Groundwater Flow 3-24 3.6.1.5 Groundwater Flow Rates 3-26

3.6.2 Deep Overburden 3-27 3.6.2.1 Hydraulic Conductivity 3-27 3.6.2.2 Piezometric Surface Elevation Measurements 3-28 3.6.2.3 Horizontal Hydraulic Gradients 3-28 3.6.2.4 Horizontal Groundwater Flow 3-29 3.6.2.5 Groundwater Flow Rates 3-29

3.6.3 Bedrock Aquifer 3-29 3.6.3.1 Hydraulic Conductivity 3-30 3.6.3.2 Piezometric Surface Elevation

Measurements 3-30 3.6.3.3 Horizontal Hydraulic Gradients 3-32 3.6.3.4 Horizontal Groundwater Flow 3-33

3.6.4 Former Lagoon Areas 3-33 3.6.4.1 Lagoon Area Hydrology 3-34 3.6.4.2 Observed Groundwater Fluctuations

and Depths 3-35

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3.6.5 Groundwater Recharge and Discharge 3-36 3.6.5.1 Upgradient Recharge Areas 3-36 3.6.5.2 Interconnection of Aquifer Systems 3-37 3.6.5.3 Groundwater/Surface Water Interaction . . . . 3-40

3.7 Ecology 3-42

4.0 SOURCE, NATURE AND EXTENT OF CONTAMINATION 4-1 4.1 Source Areas 4-1

4.1.1 NHPC Building Area 4-1 4.1.1.1 NHPC Building 4-2 4.1.1.2 Former Leachfields 4-3 4.1.1.3 Underground Fuel Oil Storage Tank 4-3 4.1.1.4 Above-ground Solvent Storage Tank 4-4 4.1.1.5 Former NHPC Production Well 4-4 4.1.1.6 Solidified Material Storage Cell 4-5

4.1.2 Former Lagoon Areas 4-5 4.1.3 Wetland and Overflow Areas 4-7 4.1.4 Summary of Source Areas 4-7

4.2 Nature of Chemical Compounds Detected at NHPC 4-9 4.2.1 Metals 4-9 4.2.2 Cyanide 4-10 4.2.3 Volatile Organic Compounds (VOCs) 4-10 4.2.4 Semi-Volatile Organic Compounds (SVOCs) 4-11 4.2.5 Pesticides/Polychlorinated Biphenyls (PCBs) 4-11 4.2.6 Petroleum Hydrocarbons 4-12

4.3 Background/Upgradient Sampling Locations 4-13 4.3.1 Background Soil Sampling 4-13

4.3.1.1 Metals 4-13 4.3.1.2 VOCs 4-15 4.3.1.3 SVOCs 4-15 4.3.1.4 Compounds Analyzed by Not Detected . . . . 4-15

4.3.2 Upgradient Groundwater Sampling 4-15 4.3.2.1 Metals 4-16 4.3.2.2 VOCs 4-16

4.3.3 Surface Water and Sediment 4-16 4.4 Extent of Contamination in Soils 4-17

4.4.1 Extent of Soils Contamination in NHPC Building Area , 4-19 4.4.1.1 Metals . . . 4-20 4.4.1.2 Cyanide 4-27

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4.4.1.3 VOCs ........................... 4-28 4.4.1.4 SVOCs .......................... 4-30 4.4.1.5 PCBs ............................ 4-30 4.4.1.6 Total Petroleum Hydrocarbons (TPH) ...... 4-30 4.4.1.7 Compounds Analyzed But Not Detected . . . . 4-31

4.4.2 Data Presentation for Former Lagoons, Wetlands, and Overflow Area .......................... 4-31

4.4.3 Extent of Soils Contamination in Former Lagoon Areas ................................... 4-33 4.4.3.1 Lagoon 1 Area ..................... 4-34 4.4.3.2 Lagoon 2 Area ..................... 4-41 4.4.3.3 Lagoon 3 and 4 Area ................. 4-49 4.4.3.4 Clean Fill Soil Sample Results ........... 4-57

4.4.4 Extent of Soils Contamination in Wetlands and Overflow Area .......................... 4-58 4.4.4.1 Southern Wetland Area ............... 4-58 4.4.4.2 Northern Wetland Area ............... 4-68 4.4.4.3 Lagoon 4 Overflow .................. 4-77

4.4.5 Other On-site Areas ......................... 4-81 4.4.5.1 Jones Chemical Run-off Area ........... 4-81 4.4.5.2 Pug Mill Area ...................... 4-82 4.4.5.3 ESD Anomally Area .................. 4-83 4.4.5.4 Stockpile Area ..................... 4-83

4.4.6 Off-site Soils .............................. 4-83 4.5 NHPC Study Area Breakdown ........................ 4-84

4.5.1 Background and Cross-Gradient Areas ............ 4-84 4.5.2 NHPC Operations Area ....................... 4-85 4.5.3 Downgradient Areas ........................ 4-85

4.6 Extent of Contamination in Ground water ................ 4-86 4.6.1 Evaluation of Ground water Analytical

Results .................................. 4-87 4.6.2 Shallow Overburden Aquifer ................... 4-88

4.6.2.1 Background and Cross-gradient Areas ..... 4-88 4.6.2.2 NHPC Operations Area ............... 4-90 4.6.2.3 Downgradient Areas ................. 4-92 4.6.2.4 Summary of Shallow Overburden

Aquifer Contamination ................ 4-94 4.6.3 Deep Overburden Aquifer .................... 4-103

4.6.3.1 Upgradient/Cross-gradient Areas ........ 4-104 4.6.3.2 NHPC Operations Area .............. 4-104

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4.6.3.3 Downgradient Areas 4-105 4.6.3.4 Summary of Deep Overburden Aquifer

Contamination 4-106 4.6.4 Bedrock Aquifer 4-110

4.6.4.1 Upgradient/Cross-gradient Areas 4-111 4.6.4.2 NHPC Operations Area 4-111 4.6.4.3 Downgradient Areas 4-112 4.6.4.4 Summary of Bedrock Aquifer

Contamination 4-112 4.7 Surface Water and Sediment Analytical Results 4-114

4.7.1 Evaluation of Surface Water and Sediment Results 4-114

4.7.2 Horseshoe Pond 4-115 4.7.2.1 Volatile Organic Compounds 4-115 4.7.2.2 SVOCs 4-116 4.7.2.3 Metals and Cyanide 4-117 4.7.2.4 Total Organic Carbon 4-118

4.7.3 Merrimack River 4-119 4.7.3.1 Volatile Organic Compounds 4-119 4.7.3.2 Metals and Cyanide 4-119 4.7.3.3 Total Organic Carbon 4-120

4.7.4 Summary of Surface Water and Sediment Contamination 4-120

5.0 CONTAMINANT FATE AND TRANSPORT 5-1 5.1 Fate and Transport Processes 5-2

5.1.1 Advection 5-2 5.1.2 Diffusion and Dispersion 5-3 5.1.3 Partitioning 5-5

5.1.3.1 Air-Water Partitioning 5-5 5.1.3.2 Soil-Water Partitioning 5-7

5.1.4 Decay 5-9 5.1.5 Dissolution and Precipitation 5-10 5.1.6 Acid/Base Reactions 5-11 5.1.7 Complexation 5-12 5.1.8 Biotic Uptake 5-12

5.2 Behavior of Contaminants 5-12 5.2.1 Metals 5-13

5.2.1.1 Cadmium 5-13 5.2.1.2 Zinc 5-14

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5.2.1.3 Chromium 5-15 5.2.1.4 Lead 5-15 5.2.1.5 Nickel 5-15

5.2.2 Organic Compounds 5-16 5.3 Discussion of Site Contamination and Transport 5-17

5.3.1 Former Lagoons 5-18 5.3.1.1 Metals and Cyanide 5-18 5.3.1.2 Volatile Organic Compounds 5-21

5.3.2 Former Building Area 5-21 5.3.2.1 Metals and Cyanide 5-22 5.3.2.2 Volatile Organic Compounds 5-22

5.3.3 Downgradient Areas 5-23 5.3.3.1 Metals and Cyanide 5-24 5.3.3.2 Volatile Organic Compounds 5-26

5.4 Summary 5-26 5.4.1 Lagoon Area Sources 5-27 5.4.2 Former Building Area Sources 5-27 5.4.3 Physical Features Influencing Fate and Transport 5-28

6.0 BASELINE HUMAN HEALTH RISK ASSESSMENT 6-1 6.1 Introduction 6-1 6.2 Hazard Identification 6-3

6.2.1 Selection of Chemicals of Concern 6-3 6.2.1.1 The Concentration-Toxicity Screen 6-4 6.2.1.2 Volatile Organic Compounds (VOCs)

of Concern 6-6 6.2.1.3 Semivolatile Organic Compounds (SVOC)

of Concern 6-8 6.2.1.4 Pesticides/PCBs- Chemicals of Concern . . . . 6-10 6.2.1.5 Inorganic Chemicals of Concern 6-11

6.2.2 Toxicity Profiles 6-14 6.2.2.1 Acetone 6-15 6.2.2.2 Antimony 6-15 6.2.2.3 Arsenic 6-17 6.2.2.4 Barium 6-17 6.2.2.5 Benzene 6-18 6.2.2.6 Beryllium 6-19 6.2.2.7 Bis(2-ethylhexyl)phthalate 6-20 6.2.2.8 2-Butanone (Methyl Ethyl Ketone) 6-20 6.2.2.9 Cadmium 6-21

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6.2.2.10 Carbon Disulfide 6-22 6.2.2.11 Chloroform 6-22 6.2.2.12 Chromium 6-23 6.2.2.13 Cobalt 6-24 6.2.2.14 Copper 6-26 6.2.2.15 Cyanide 6-27 6.2.2.16 DDT (4,4'-Dichlorodiphenyl

trichloroethane) 6-28 6.2.2.17 1,2-Dichloroethane 6-30 6.2.2.18 1,1-Dichloroethene (1,1-DCE) 6-30 6.2.2.19 1,1-Dichloroethane 6-31 6.2.2.20 Cis-1,2-Dichloroethene (Cis-1,2-Dichloro

ethylene) 6-32 6.2.2.21 Trans-1,2-Dichloroethene (Trans-1,2

Dichloroethylene) 6-32 6.2.2.22 Di-n-butylphthalate (Dibutylphthalate) 6-33 6.2.2.23 Lead 6-33 6.2.2.24 Manganese 6-34 6.2.2.25 Mercury and Mercury Compounds 6-35 6.2.2.26 Methylene Chloride 6-35 6.2.2.27 Nickel 6-36 6.2.2.28 Polychlorinated Biphenyl Compounds (PCBs) . 6-37 6.2.2.29 Polynuclear Aromatic Hydrocarbons (PAHs) . 6-37 6.2.2.30 Selenium 6-39 6.2.2.31 Silver 6-39 6.2.2.32 Tetrachloroethene 6-40 6.2.2.33 Inorganic Tin 6-40 6.2.2.34 1,1,1-Trichloroethane 6-41 6.2.2.35 Trichloroethene (TCE) 6-41 6.2.2.36 Vanadium 6-42 6.2.2.37 Vinyl Chloride 6-42 6.2.2.38 Zinc 6-43

6.3 Dose-Response Assessment 6-43 6.3.1 Toxicity Criteria (Dose-Response Parameters) 6-44

6.3.1.1 Reference Dose (RfD) 6-44 6.3.1.2 Carcinogenic Slope Factor (CSF) 6-45

6.3.2 Criteria/Standards 6-46 6.3.2.1 Maximum Contaminant Levels (MCLs) 6-46 6.3.2.2 Maximum Contaminant Level Goals (MCLGs) 6-46

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6.3.2.3 Ambient Water Quality Criteria (AWQC) . . . . 6-47 6.3.2.4 Health Advisories (HAs) 6-47

6.4 Exposure Assessment 6-47 6.4.1 The NHPC Site Environmental Setting and

Sources of Contamination 6-48 6.4.1.1 Potential Sources of Contamination 6-48 6.4.1.2 Site-Related Chemicals 6-49 6.4.1.3 Summary of Environmental Contamination . . 6-49

6.4.2 Contaminant Transport and Migration 6-50 6.4.3 Receptor Identification and Exposure Routes 6-51

6.4.3.1 Demographics and Land/Water Use Patterns . 6-51 6.4.3.2 Human Receptors of Concern 6-53 6.4.3.3 Exposure Routes 6-54

6.5 Risk Assessment 6-61 6.5.1 Methodology for Estimation of Carcinogenic Risks . . . . 6-61 6.5.2 Methodology for Estimation of Noncarcinogenic Risks . . 6-62 6.5.3 Risk Assessment Results 6-63

6.5.3.1 Risk Assessment Results for Soil Exposure Scenarios 6-63

6.5.3.2 Risk Assessment Results for Groundwater Exposure Scenarios 6-70

6.5.3.3 Risk Assessment Results for Surface Water/ Sediment Exposure Scenarios 6-74

6.5.4 Uncertainty in Risk Assessment 6-75 6.6 Summary of the Baseline Risk Assessment Results 6-77

7.0 ECOLOGICAL RISK ASSESSMENT 7-1 7.1 Site Description and Potential Receptors 7-1

7.1.1 Characteristics of the Study Area 7-1 7.1.2 Habitats and Potentially Exposed Receptor Groups 7-3 7.1.3 Nature and Extent of Contamination 7-5

7.2 Contaminants and Areas of Concern, Indicator Species, and Ecological Endpoints 7-9 7.2.1 Identification of Areas and Contaminants of Concern . . . 7-9 7.2.2 Selection of Indicator Species 7-11 7.2.3 Selection of Ecological Endpoints 7-13

7.3 Ecological Effects Assessment 7-14 7.3.1 Reported Toxic and Ecological Effects of Cadmium . . . 7-15 7.3.2 Benchmark Toxicity Values for Cadmium 7-22 7.3.3 Uncertainty Analysis 7-23

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7.4 Exposure Assessment 7-23 7.4.1 Fate and Transport Analysis 7-24 7.4.2 Soil Exposure Assessment 7-26 7.4.3 Uncertainty Analysis 7-33

7.5 Risk Characterization 7-35 7.5.1 Risk from Soil Contamination by Cadmium 7-36 7.5.2 Uncertainty Analysis 7-39

7.6 Summary and Conclusions of the Ecological Risk Assessment . . 7-42

8.0 CONCLUSIONS AND RECOMMENDATIONS 8-1 8.1 Study Area Hydrology, Geology, and Hydrogeology 8-1 8.2 Source and Nature of Contaminants 8-3 8.3 Surface and Subsurface Soil Contamination 8-5 8.4 Groundwater Contamination 8-7 8.5 Surface Water and Sediment Contamination 8-9 8.6 Human Health and Ecological Risk Assessment 8-10 8.7 Recommendations 8-11

REFERENCES

TABLES

NUMBER PAGE

2-1 Previously Installed Monitoring Well and Piezometers Drilling and Installation Summary Volume 2

2-2 Phase I Surface Soil CLP Sampling Locations and Analytical Parameters Volume 2

2-3 CLP Sampling Locations and Analytical Parameters Volume 2 2-4 CLP Sample Locations and Analytical Parameters Volume 2 2-5 Phase II Lagoon Soil Boring Program Volume 2 2-6 Lagoon Soil Boring Analytical Summary Volume 2 2-7 Newly Installed Monitoring Wells and Piezometers

Drilling and Installation Summary Volume 2 2-8 Monitoring Well/Soil Boring Sampling and Analytical Summary . Volume 2 2-9 Summary of Groundwater Elevations and Saturated Thickness

Shallow Groundwater Monitoring Wells Volume 2 2-10 Summary of Groundwater Elevations Deep Overburden and

Bedrock Monitoring Wells Volume 2 2-11 Summary of Groundwater Elevations Former Lagoon Areas . . . Volume 2

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2-12 Ground water Sampling and Analytical Summary Volume 2 2-13 Surface Water Sampling and Analytical Summary Volume 2 2-14 Sediment Sampling and Analytical Summary Volume 2 2-15 Summary of Field and QA/QC Samples Volume 2 3-1 Depths to Ground water Below Ground Surface Former Lagoon

Area Piezometer Locations Volume 2 3-2 Summary of Vertical Hydraulic Gradients Volume 2 4-1 Volatile Organic Compounds Detected in the NHPC

Study Area Volume 2 4-2 Semi-Volatile Organic Compounds Detected in the

NHPC Study Area Volume 2 4-3 XRF and ICP Background Metals Results, Phase I Surficial

Soil Sampling Volume 2 4-4 Detected Contaminants in the Horseshoe Pond Sediment,

Phase II Sampling: 1993 Volume 2 4-5 Detected Contaminants in the Merrimack River Sediment,

Phase II Sampling: 1993 Volume 2 4-6A Metals and Cyanide Analytical Results, Phase I Lagoon

Soil Boring Program, 1992 Volume 2 4-6B Metals and Cyanide Analytical Results, Phase I Lagoon

Soil Sampling Program, 1992 Volume 2 4-7A Metals and Cyanide Analytical Results: Lagoon Areas,

Phase II Lagoon Soil Boring Program: 1993 Volume 2 4-7B Metals and Cyanide Analytical Results: Lagoon Areas,

Phase II Lagoon Soil Boring Program: 1993 Volume 2 4-7C Metals and Cyanide Analytical Results: Lagoon Areas,

Phase II Lagoon Soil Boring Program: 1993 Volume 2 4-7D Metals and Cyanide Analytical Results: Southern Wetland,

Phase II Lagoon Soil Boring Program: 1993 Volume 2 4-7E Metals and Cyanide Analytical Results: Northern Wetland,

Phase II Lagoon Soil Boring Program: 1993 Volume 2 4-7F Metals and Cyanide Analytical Results: Lagoon 4 Overflow

Area, Phase II Lagoon Soil Boring Program: 1993 Volume 2 4-8 Phase I Surficial Soil CLP Analytical Results Volume 2 4-9 XRF Metals and CLP Analytical Results, Building Area

Soil Borings Volume 2 4-10 Detected Contaminants in the Building Soil Sampling

Program: 1994 Volume 2 4-11 Field GC Screening Results Volume 2

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4-12 Summary of Samples with 0-2 Foot Depth Designations, Phase II Lagoon Soil Boring Program Volume 2

4-13 Detected TCLP Contaminants in the Lagoon Areas, Phase II Lagoon Soil Sampling: 1993 Volume 2

4-14 Detected Contaminants in the Soil Samples, Phase I Soil Sampling: 1992 Volume 2

4-15 Detected Contaminants in the Shallow Overburden Aquifer, Phase II Groundwater Sampling: 1993 Volume 2

4-16 Detected Contaminants in the Deep Overburden Aquifer, Phase II Groundwater Sampling: 1993 Volume 2

4-17 Detected Contaminants in the Bedrock Overburden Aquifer, Phase II Groundwater Sampling: 1993 Volume 2

4-18 Frequency of MCL Exceedances in Groundwater Volume 2 5-1 Comparison of TCLP and Total Cadmium in Soil Volume 2 6-1 Toxicity Criteria for Chemicals Detected in Environmental

Media Samples Volume 2 6-2 Selection of Chemicals of Concern for Groundwater Volume 2 6-3 Selection of Chemicals of Concern for Soil Volume 2 6-4 Selection of Chemicals of Concern for Surface Water Volume 2 6-5 Selection of Chemicals of Concern for Sediment Volume 2 6-6 Summary of Chemicals of Concern for Risk Assessment Volume 2 6-7 Standards and Criteria for Chemicals of Concern Volume 2 6-8 Exposure Scenarios for the New Hampshire Plating Site Volume 2 6-9 Summary of Input Parameters for Intake Equations Volume 2 6-10A Carcinogenic Risk Assessment Results for Shallow Soil

Exposure Pathways Accidental Ingestion and Dermal Contact by an Industrial Worker (Future Land Use Scenario) or Trespasser (Current Land Use Scenario) Lagoon Soils Volume 2

6-1 OB Noncarcinogenic Risk Assessment Results for Shallow Soil Exposure Pathways Accidental Ingestion and Dermal Contact by an Industrial Worker (Future Land Use Scenario) or Trespasser (Current Land Use Scenario) Lagoon Soils Volume 2

6-11A Carcinogenic Risk Assessment Results for Shallow Soil Exposure Pathways Accidental Ingestion and Dermal Contact by an Industrial Worker (Future Land Use Scenario) or Trespasser (Current Land Use Scenario) Lagoon 1 Soils Volume 2

6-11B Noncarcinogenic Risk Assessment Results for Shallow Soil Exposure Pathways Accidental Ingestion and Dermal Contact by an Industrial Worker (Future Land Use Scenario) or

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MERRIMACK, NEW HAMPSHIRE

NUMBER PAGE

Trespasser (Current Land Use Scenario) Lagoon 1 Soils . . . . . . . Volume 2 6-12A Carcinogenic Risk Assessment Results for Shallow Soil

Exposure Pathways Accidental Ingestion and Dermal Contact by an Industrial Worker (Future Land Use Scenario) or Trespasser (Current Land Use Scenario) Lagoon 2 Soils Volume 2

6-12B Noncarcinogenic Risk Assessment Results for Shallow Soil Exposure Pathways Accidental Ingestion and Dermal Contact by an Industrial Worker (Future Land Use Scenario) or Trespasser (Current Land Use Scenario) Lagoon 2 Soils Volume 2

6-13A Carcinogenic Risk Assessment Results for Shallow Soil Exposure Pathways Accidental Ingestion and Dermal Contact by an Industrial Worker (Future Land Use Scenario) or Trespasser (Current Land Use Scenario) Lagoons 3 and 4 Soils Volume 2

6-13B Noncarcinogenic Risk Assessment Results for Shallow Soil Exposure Pathways Accidental Ingestion and Dermal Contact by an Industrial Worker (Future Land Use Scenario) or Trespasser (Current Land Use Scenario) Lagoons 3 and 4 Soils Volume 2

6-14A Carcinogenic Risk Assessment Results for Shallow Soil Exposure Pathways Accidental Ingestion and Dermal Contact by an Industrial Worker (Future Land Use Scenario) or Trespasser (Current Land Use Scenario) Northern Wetlands . . . Volume 2

6-14B Noncarcinogenic Risk Assessment Results for Shallow Soil Exposure Pathways Accidental Ingestion and Dermal Contact by an Industrial Worker (Future Land Use Scenario) or Trespasser (Current Land Use Scenario) Northern Wetlands . . . Volume 2

6-15A Carcinogenic Risk Assessment Results for Shallow Soil Exposure Pathways Accidental Ingestion and Dermal Contact by an Industrial Worker (Future Land Use Scenario) or Trespasser (Current Land Use Scenario) Southern Wetlands . . . Volume 2

6-15B Noncarcinogenic Risk Assessment Results for Shallow Soil Exposure Pathways Accidental Ingestion and Dermal Contact by an Industrial Worker (Future Land Use Scenario) or Trespasser (Current Land Use Scenario) Southern Wetlands . . . Volume 2

6-16A Carcinogenic Risk Assessment Results for Shallow Soil Exposure Pathways Accidental Ingestion and Dermal Contact by Future Adult and Young Child Residents Building Phase II Data Volume 2

W94619DF xiii

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TABLE OF CONTENTS (Continued) VOLUME 1 - TEXT

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NUMBER PAGE

6-16B Noncarcinogenic Risk Assessment Results for Shallow Soil Exposure Pathways Accidental Ingestion and Dermal Contact by Future Adult and Young Child Residents Building Phase II Data Volume 2

6-16C Carcinogenic Risk Assessment Results for Shallow Soil Exposure Pathways Accidental Ingestion and Dermal Contact by Future Adult and Young Child Residents Building Phase I . . Volume 2

6-16D Noncarcinogenic Risk Assessment Results for Surface Soil (0 to 2 feet) Exposure Pathways Accidental Ingestion and Dermal Contact by Future Adult and Young Child Residents Building Phase I Volume 2

6-17A Carcinogenic Risk Assessment Results for Shallow Soil Exposure Pathways Accidental Ingestion and Dermal Contact by an Industrial Worker (Future Land Use Scenario) or Trespasser (Current Land Use Scenario) Building Area Volume 2

6-17B Noncarcinogenic Risk Assessment Results for Shallow Soil Exposure Pathways Accidental Ingestion and Dermal Contact by an Industrial Worker (Future Land Use Scenario) or Trespasser (Current Land Use Scenario) Building Area Volume 2

6-17C Carcinogenic Risk Assessment Results for Shallow Soil Exposure Pathways Accidental Ingestion and Dermal Contact by an Industrial Worker (Future Land Use Scenario) or Trespasser (Current Land Use Scenario) Building Phase I Data . Volume 2

6-17D Noncarcinogenic Risk Assessment Results for Shallow Soil Exposure Pathways Accidental Ingestion and Dermal Contact by an Industrial Worker (Future Land Use Scenario) or Trespasser (Current Land Use Scenario) Building Area Volume 2

6-18A Carcinogenic Risk Assessment Results for Shallow Soil Exposure Pathways Accidental Ingestion and Dermal Contact by Future Adult and Young Child Residents, Jones Chemical . . Volume 2

6-18B Noncarcinogenic Risk Assessment Results for Shallow Soil Exposure Pathways Accidental Ingestion and Dermal Contact by Future Adult and Young Child Residents, Jones Chemical . . Volume 2

6-19A Carcinogenic Risk Assessment Results for Shallow Soil Exposure Pathways Accidental Ingestion and Dermal Contact by an Industrial Worker (Future Land Use Scenario) or Trespasser (Current Land Use Scenario), Jones Chemical Soils . Volume 2

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TABLE OF CONTENTS (Continued) VOLUME 1 - TEXT

DRAFT FINAL REMEDIAL INVESTIGATION REPORT NEW HAMPSHIRE PLATING COMPANY SITE

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6-19B Noncarcinogenic Risk Assessment Results for Shallow Soil Exposure Pathways Accidental Ingestion and Dermal Contact by an Industrial Worker (Future Land Use Scenario) or Trespasser (Current Land Use Scenario), Jones Chemical Soils . Volume 2

6-20A Carcinogenic Risk Analysis Results for Groundwater Exposure Pathways (RME Receptor) Ingestion of Background (Shallow Overburden) Groundwater as Drinking Water by Future Adult Residents Volume 2

6-20B Noncarcinogenic Risk Analysis Results for Groundwater Exposure Pathways (RME Receptor) Ingestion of Background (Shallow Overburden) Groundwater as Drinking Water by Future Adult Residents Volume 2

6-20C Carcinogenic Risk Analysis Results for Groundwater Exposure Pathways (CT Receptor) Ingestion of Background (Shallow Overburden) Groundwater as Drinking Water by Future Adult Residents Volume 2

6-20D Noncarcinogenic Risk Analysis Results for Groundwater Exposure Pathways (CT Receptor) Ingestion of Background (Shallow Overburden) Groundwater as Drinking Water by Future Adult Residents Volume 2

6-21A Carcinogenic Risk Analysis Results for Groundwater Exposure Pathways (RME Receptor) Ingestion of Background (Deep Overburden) Groundwater as Drinking Water by Future Adult Residents Volume 2

6-21B Noncarcinogenic Risk Analysis Results for Groundwater Exposure Pathways (RME Receptor) Ingestion of Background (Deep Overburden) Groundwater as Drinking Water by Future Adult Residents Volume 2

6-21C Carcinogenic Risk Analysis Results for Groundwater Exposure Pathways (CT Receptor) Ingestion of Background (Deep Overburden) Groundwater as Drinking Water by Future Adult Residents Volume 2

6-21D Noncarcinogenic Risk Analysis Results for Groundwater Exposure Pathways (CT Receptor) Ingestion of Background (Deep Overburden) Groundwater as Drinking Water by Future Adult Residents Volume 2

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TABLE OF CONTENTS (Continued) VOLUME 1 - TEXT

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NUMBER

6-22A Carcinogenic Risk Analysis Results for Groundwater Exposure Pathways (RME Receptor) Ingestion of Background (Bedrock) Groundwater as Drinking Water by Future Adult Residents Volume 2

6-22B Noncarcinogenic Risk Analysis Results for Groundwater Exposure Pathways (RME Receptor) Ingestion of Background (Bedrock) Groundwater as Drinking Water by Future Adult Residents Volume 2

6-22C Carcinogenic Risk Analysis Results for Groundwater Exposure Pathways (CT Receptor) Ingestion of Background (Bedrock) Groundwater as Drinking Water by Future Adult Residents Volume 2

6-22D Noncarcinogenic Risk Analysis Results for Groundwater Exposure Pathways (CT Receptor) Ingestion of Background (Bedrock) Groundwater as Drinking Water by Future Adult Residents Volume 2

6-23A Carcinogenic Risk Analysis Results for Groundwater Exposure Pathways (RME Receptor) Ingestion of Upgradient (Shallow Overburden) Groundwater as Drinking Water by Future Adult Residents Volume 2

6-23B Noncarcinogenic Risk Analysis Results for Groundwater Exposure Pathways (RME Receptor) Ingestion of Upgradient (Shallow Overburden) Groundwater as Drinking Water by Future Adult Residents Volume 2

6-23C Carcinogenic Risk Analysis Results for Groundwater Exposure Pathways (CT Receptor) Ingestion of Upgradient (Shallow Overburden) Groundwater as Drinking Water by Future Adult Residents Volume 2

6-23D Noncarcinogenic Risk Analysis Results for Groundwater Exposure Pathways (CT Receptor) Ingestion of Upgradient (Shallow Overburden) Groundwater as Drinking Water by Future Adult Residents Volume 2

6-24 Summary of Risk Assessment Results for Groundwater Volume 2 6-25 Summary of Risk Assessment Results for Soils Volume 2 7-1 Plant Species Present in the Study Area Volume 2 7-2 Mammal Species Associated with the Study Area Volume 2 7-3 Bird Species Associated with the Study Area Volume 2 7-4 Amphibian and Reptile Species Associated with the

Study Area Volume 2

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TABLE OF CONTENTS (Continued) VOLUME 1 - TEXT

DRAFT FINAL REMEDIAL INVESTIGATION REPORT NEW HAMPSHIRE PLATING COMPANY SITE

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NUMBER

7-5 Fish Species Associated with the Study Area Volume 2 7-6 Soil Contaminants Detected in the 0 to 2 Foot Depth Interval Volume 2 7-7 Characterization of the Indicator Species Volume 2 7-8 Bioaccumulation Factors for Earthworms and other Terrestrial Volume 2

Invertebrates 7-9 Cadmium Soil Concentration Estimates Derived from the Food Volume 2

Web Model 7-10 Cadmium Risk Estimates for the Indicator Species Volume 2

EXHIBITS

NUMBER

6-1 Ingestion of Groundwater Residential Land Use Scenario Volume 2 6-2 Incidental Ingestion of Soils Residential Land Use and Volume 2

Trespassing Scenarios 6-3 Dermal Contact with Soils Residential Land Use and Volume 2

Trespassing Scenarios 6-4 Incidental Ingestion of Soils Industrial Land Use Scenario . . . . Volume 2 6-5 Dermal Contact with Soils Industrial Land Use Scenario Volume 2 6-6 Incidental Ingestion of Sediments Recreational Land Use Volume 2

and Trespassing Scenarios 6-7 Dermal Contact with Sediments Recreational Land Use

Scenario Volume 2

FIGURES

NUMBER PAGE

1-1 Site Location Map Volume 3 1-2 Study Area Location Map Volume 3 2-1 Previously Installed Monitoring Well and Piezometer

Location Map Volume 3 2-2 Groundwater Elevation Contour Map, Shallow Overburden

Aquifer, 24 August 1992 Volume 3 2-3 Building Area Soil Sampling Location Map Volume 3 2-4 Lagoon Soil Boring Location Map Volume 3

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TABLE OF CONTENTS (Continued) VOLUME 1 - TEXT

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NUMBER

2-5 Phase I Surficial Soil Sampling Location Map Volume 3 2-6 Phase I Lagoon Sampling Location Map Volume 3 2-7 Cyanide Sampling Location Map, Lagoon Soil Boring Program . Volume 3 2-8 TCLP Sampling Location Map, Lagoon Soil Boring Program . . . Volume 3 2-9 VOC Sampling Location Map, Lagoon Soil Boring Program . . . . Volume 3 2-10 Chrome VI Sampling Location Map, Lagoon Soil

Boring Program Volume 3 2-11 Wetlands Restoration Sampling Location Map Volume 3 2-12 Newly Installed Monitoring Well and Piezometer Location Map . Volume 3 2-13 Soil Vapor Survey Sampling Location Map Volume 3 2-14 Monitoring Well and Piezometer Location Map Volume 3 2-15 Groundwater Sampling Location Map Volume 3 2-16 Surface Water and Sediment Sampling Location Map Volume 3 3-1 Geological Cross-Section Line Location Map (NHPC

Study Area) Volume 3 3-2 Geological Cross-Section A-A' Volume 3 3-3 Geological Cross-Sections B-B' and C-C' Volume 3 3-4 Glacio-Lacustrine Unit Surface Elevation Contour Map Volume 3 3-5 Geological Cross-Section Line Location Map (Former

Lagoon Area) Volume 3 3-6 Lagoon Area Cross-Sections Volume 3 3-7 Bedrock Surface Elevation Contour Map Volume 3 3-8 Groundwater Elevation Contour Map, Shallow Overburden

Aquifer, 30 November 1993 Volume 3 3-9 Piezometric Surface Elevation Contour Map, Deep

Overburden Aquifer, 30 November 1993 Volume 3 3-10 Piezometric Surface Elevation Contour Map, Bedrock

Aquifer, 30 November 1993 Volume 3 3-11 Groundwater Contaminant Distribution Cross-Section

Location Map Volume 3 3-12 Flow Net Cross-Section l-l' (Shallow and Deep

Overburden Aquifers) Volume 3 3-13 Water Level Hydrograph, Selected Wells Volume 3 4-1 Building Area Detail Map Volume 3 4-2 Phase II Lagoon Sampling - South Cadmium Concentrations

in Soil Volume 3 4-3 Phase II Lagoon Sampling - North Cadmium Concentrations

in Soil Volume 3 4-4 Study Area Breakdown Map Volume 3

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TABLE OF CONTENTS (Continued) VOLUME 1 - TEXT

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4-5 MCL Exceedance Map, Volatile Organic Compounds in Groundwater Volume 3

4-6 Contaminant Contour Map (TCE in Groundwater) Shallow Overburden Aquifer Volume 3

4-7 MCL Exceedance Map, Metals in Groundwater Volume 3 4-8 Contaminant Concentration, Cross Section J-J', TCE in

Groundwater Volume 3 4-9 Contaminant Contour Map (Cadmium in Groundwater)

Shallow Overburden Aquifer Volume 3 4-10 Contaminant Concentration, Cross-Section A-A', TCE in . . . . Volume 3

Groundwater 4-11 Contaminant Concentration, Cross Section l-l', TCE in

Groundwater Volume 3 4-12 MCL Exceedances in Overburden Groundwater Volume 3 7-1 Habitat Distribution Map Volume 3 7-2 Lagoons-Wetlands System, Area of Concern for the

Ecological Soil Exposure Pathway Volume 3

APPENDICES (VOLUME IV)

Appendix A Building Area Soil Borings Log Appendix B Monitoring Well/Soil Boring Logs Appendix C Soil Vapor Survey Report Appendix D Low Flow Groundwater Sampling Procedure Appendix E Phase I Soil Analytical Results Appendix F Phase II Soil Analytical Results Appendix G Groundwater Analytical Results Appendix H Surface Water/Sediment Analytical Results Appendix I XRF Comparison to ICP Data Appendix J Groundwater Sampling Log Sheets For Low Flow Sampling (December

1993)

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E.O EXECUTIVE SUMMARY

Halliburton NUS Corporation (HNUS) and Raytheon Engineers and Constructors (REC,

formerly Badger Engineers, Inc.) conducted a Remedial Investigation (Rl) at the New

Hampshire Plating Company (NHPC) Superfund Site located in Merrimack, New

Hampshire, under U.S. EPA Work Assignment No. 33-1GL1, Contract No.

68-W8-0117. The Rl evaluated the physical characteristics of the site; the source,

nature and extent, and fate and transport of the site contaminants; and the human

health and ecological risks posed by the site. The results of the Rl indicate that soils

within the NHPC property are contaminated with metals, most significantly cadmium,

and that the groundwater beneath and migrating from the NHPC property is

contaminated with metals, most notably cadmium, and volatile organic compounds

(VOCs), principally trichloroethylene (TCE). The Rl further concludes that the

contaminated soils present a direct risk to ecological receptors, and an indirect risk to

human receptors through leaching of the contaminants to groundwater. The

contaminated groundwater was found to present a human health risk, and to exceed

regulatory levels for several of the detected contaminants in drinking water.

The principle site contaminants are:

Volatile Organic Compounds (VOCs)

• Tetrachloroethylene (PCE)

• Trichloroethylene (TCE)

• 1,1,1 -trichloroethane (TCA)

Cyanide

Metals

• Cadmium • Lead

• Zinc • Nickel

• Chromium • Tin

• Copper

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DRAFT FINAL

Physical Characteristics

The NHPC site is located Wright Avenue in Merrimack (Hillsborough County), New

Hampshire. The study area investigated during the Rl includes the NHPC Operations

Area and adjacent properties and surface water bodies as noted below:

NHPC Operations Area

• NHPC Building

• Lagoons 1, 2, 3, and 4

• Northern Wetland Area

• Southern Wetland Area

Adjacent Properties

• Magnum Leasing Property

• YMCA Property

• Horseshoe Pond Island Property

• New England Pole Wood Treating Corporation Property

• Lot Number 22 Property

• Techwood Building Systems, Inc. Property

• Jones Chemical, Inc. Property

Surface Water Bodies

• Horseshoe Pond

• Merrimack River

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Historical information

NHPC operated an electroplating facility on the site from 1962 to 1985. The metals

used in the electroplating process included cadmium, zinc, chromium, copper, lead,

nickel, tin, gold, silver, aluminum, iron, and manganese. The chlorinated organic

solvents used included trichloroethylene, 1,1,1-trichloroethane, and

tetrachloroethylene. Cyanide was also used in the electroplating process. Chlorinated

solvent use was reportedly discontinued during the latter part of the 1970s.

Electroplating wastes generated by the NHPC facility included metals, VOCs, cyanide,

and acids (Weston, 19901).

Treated and untreated wastes and wastewater were collected in various drainage

channels constructed within the concrete floors in the processing areas of the NHPC

building. The wastes were then gravity-drained through an underground discharge

pipe to unlined waste lagoons located approximately 325 feet north of the building.

Wastes were discharged directly into a primary infiltration lagoon (Lagoon 1). The

lagoon system was constructed to allow the discharged wastes to flow from the

primary lagoon into a secondary infiltration lagoon (Lagoon 2} and subsequent

overflow lagoons (Lagoons 3 and 4) during periods of high discharge from the facility.

Approximately 35,000 to 60,000 gallons of wastewater were generated and

discharged to the lagoons each day (Bracchi, 1992).

In 1980, NHPC notified the U.S. Environmental Protection Agency (EPA) that it was

a hazardous waste disposal facility according to the Resource and Conservation

Recovery Act (RCRA) Section 3001 regulations. NHPC continued to operate, and as

a result of inspections by EPA and the New Hampshire Department of Environmental

Services (NHDES), received several Notices of Violation/Orders of Abatement for

failure to comply with RCRA transportation, storage, and disposal requirements, and

for failure to treat its cyanide wastewater prior to discharge. Operations at NHPC

ceased in November 1985.

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In June 1987, the NHDES initiated interim remedial measures at the site that

consisted of removing waste materials (plating solutions, cyanide salts, and other

materials) from the NHPC building. Sludge and sediment were also removed from the

building floors and disposed of at an approved off-site facility. Additionally, Lagoon

1 was treated with approximately 127 tons of lime and 800 gallons of a sodium

hypochlorite solution of unknown concentration (Weston, 19901).

The U.S. EPA Emergency Response Team (ERT) initiated an emergency removal action

in October of 1989. After a preliminary study in the fall of 1990 and spring of 1991,

EPA performed a limited on-site removal action involving the excavation of sludge and

soil from the lagoons. Approximately 13,600 tons of material was excavated,

solidified on site in an ash/mortar mix, and encapsulated in a high density polyethylene

(HDP) Solidified Material Storage Cell at a location immediately north of the NHPC

building. An additional 5,000 tons of soil were disposed off site at a secured landfill.

As the last step of the removal action, approximately 5,600 cubic yards of material

excavated from the overflow lagoon areas were placed in the former primary lagoon

area (Lagoon 1 Area). The material was covered with a HDP cap and approximately

two feet of clean fill. The other excavated lagoon areas were covered with 1 to 6

feet of clean fill.

EPA also undertook a Non-Time-Critical Removal Action (NTCRA) at the NHPC building

site in November and December of 1994. Laboratory wastes from within the building

were packed in drums for off-site shipment; asbestos-containing material was

removed; process equipment and the building were decontaminated; the building, floor

slab, and foundation were demolished; an underground storage tank was removed;

and the building footprint was graded and covered with geomembrane. Both non

hazardous and hazardous materials generated during the building removal were

disposed of off site.

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Geologic and Hydrogeologic Features

The Merrimack River flows from north to south along the eastern boundary of the

study area. Horseshoe Pond, a recreational water body, is located on the southern

boundary of the study area. The land surface generally slopes downward to the

southeast. The lowest elevations are located within the former lagoons and wetland

areas on the NHPC property. The Merrimack River is the low point of the study area.

The study area lies within the drainage basin of the Merrimack River and its

tributaries. The east-flowing Souhegan River joins the Merrimack River approximately

1500 feet north of the NHPC property. Surface water from Horseshoe Pond, an

oxbow lake, flows into the Merrimack River through an outlet stream at the

southeastern end of the pond. Surface drainage within the study area is controlled

primarily by topographic features. Because the study area is predominantly unpaved,

much of the surface water infiltrates directly into the subsurface soils during light and

moderate precipitation periods.

The subsurface soils encountered during the Rl, in order from ground surface to

bedrock, generally consist of alluvial sand deposits with glacio-lacustrine, glacial

outwash, and glacial till deposits. The lower permeability glacio-lacustrine deposits

were observed in the subsurface soils across much, but not all, of the study area. A

bedrock trough, between the NHPC building and Horseshoe Pond, oriented in an

approximate north-south direction, extends across the southern portion of the study

area. The bedrock surface rises steeply in all directions away from the central bedrock

low area. Bedrock cores collected during the Rl indicated that the dominant rock

types encountered in the study area were granite and granite gneiss, with some

schist.

Three water bearing formations in the study area include a shallow overburden, deep

overburden, and bedrock aquifers:

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DRAFT FINAL

• The shallow overburden aquifer is generally situated between 5 and 40

feet below ground surface, is generally unconfined, and is bounded at

depth by lower permeability glacio-lacustrine soils.

• The deep overburden aquifer is generally below the glacio-lacustrine soil

unit within the glacial outwash sand deposits. This aquifer is semi-

confined by upper (glacio-lacustrine) and lower (bedrock) hydraulic

boundaries of less permeable formations over most of the study area,

except where the glacio-lacustrine soils are absent. It ranges between

10 and 75 feet thick across the study area showing a general trend of

thinning toward do wngradient locations adjacent to the Merrimack River.

Historically, the deep overburden aquifer contained lower levels of

contaminants than the shallow overburden aquifer.

• The bedrock aquifer generally includes the entire bedrock section

beneath the study area. In general, this aquifer contained lower levels

of contamination than the shallow and deep overburden aquifers.

Horizontal flow within the shallow overburden is from areas of higher to lower

elevation. Groundwater within the shallow and deep overburden aquifers

predominantly flows in a southeasterly and easterly direction toward the Merrimack

River. Horizontal flow within the bedrock aquifer appears to be in an easterly direction

toward the Merrimack River.

Conversely, upward vertical gradients were generally observed between these aquifers

in the southern and eastern portions of the study area. Downward vertical gradients

occur in the northern and western portions of the study area between the shallow and

deep overburden aquifers.

Sources of Contamination

The historic sources of metals, cyanide, and VOCs at the site are:

W94619DF ES-6

E.2

DRAFT FINAL

• the release of effluent from the discharge trenches within the building;

• the release of effluent from the overflow pipes along the north wall of

the building;

• the discharge of effluent to Lagoon 1 ;

• the migration of effluent from Lagoon 1 to Lagoons 2, 3, and 4; and

• the overflow of the effluent from the lagoons to adjacent wetlands and

soils.

The results of the Rl and previous investigations also indicate that the current sources

of contamination can be summarized as follows:

• The surface soils and subsurface soils both above and below the

groundwater table in the Lagoon 1 Area are continuing sources of

cadmium and other metals to the groundwater.

• To a lesser extent, the subsurface soils in the building area may be a

continuing source of cadmium and other metals to the groundwater.

• The subsurface soils below the groundwater table in the Lagoon 1 Area

are a continuing source of chlorinated VOC contamination to the

groundwater.

• The surface soils and subsurface soils in the embankments and basins

of Lagoons 2, 3, and 4; the Southern Wetland; Northern Wetland; and

Lagoon 4 Overflow Areas are continuing sources of cadmium and other

metals.

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DRAFT FINAL

• Cadmium and chlorinated VOCs in groundwater are migrating east and

southeast, and are likely a current and/or potential source of contaminant

discharge to the Merrimack River.

The Lagoon 1 soils represent the most significant source of the highest levels of

contamination in the study area.

E.3 Nature and Extent of Contamination

The nature of contaminants detected within the NHPC study area corresponds to the

known plating effluent constituents released during the facility operations. These

contaminants include metals (cadmium, zinc, chromium, lead, nickel, copper, tin),

chlorinated solvents, (TCE and its degradation products), and cyanide.

E.3.1 Extent of Contamination in Soils

NHPC Building Area Soils

The highest residual levels of metals and VOCs were found along the northern side

of the former building, where the overflow pipes discharged through the building wall.

Contamination was generally higher in the surface soil, decreasing with depth. The

highest level of cadmium detected was 172 mg/Kg from a location beneath where the

former discharge trench exited the building.

Detectable levels of cyanide were found in 22 soils samples taken from the building

area. The highest level of cyanide detected was 87.7 mg/Kg.

VOC field screening results indicated the presence of trichloroethylene (TCE), trans-

1,2-dichloroethene (T-DCE), 1,1,1-trichloroethane (TCA), tetrachloroethylene (PCE),

and benzene around the building, and TCE in the vicinity of the former septic system.

No appreciable levels of VOCs were detected by laboratory analysis.

W94619DF ES-8

DRAFT FINAL

Former Lagoon Area Soils

Although some VOCs were detected during field screening of Lagoon 1 soils, no

appreciable chlorinated VOCs were detected in laboratory samples from any of the

lagoons. The metals detected above background concentrations are cadmium,

chromium, copper, lead, nickel, tin, and zinc. Cyanide was also detected.

The following paragraphs summarize the distribution of these inorganic contaminants.

Lagoon 1

High concentrations of cadmium and zinc were detected in Lagoon 1 soils, with

generally the highest levels (cadmium, 623 mg/Kg) in subsurface soils from the

embankments and from the backfilled soils. Their presence in the lagoon

embankments suggests that plating effluent infiltrated the area laterally. Their

presence in the surface soils suggests that plating effluent from the lagoon periodically

overflowed to perimeter areas. The shallow nature of the metals contamination

detected in both surface and subsurface soils in the southwestern corner of the

Lagoon 1 Area indicates that plating effluent overflowed and/or infiltrated laterally

southwest of the former lagoon to the topographically lower Southern Wetland area.

Metals presence in the formerly remediated and filled portion of the Lagoon 1 Area

indicates that their concentrations in the contaminated soil fill are generally

homogeneous. The concentrations decrease at depths below the contaminated fill in

soil samples that entirely penetrate the undisturbed soils beneath the fill.

Cyanide was detected in 11 of 13 soil samples; 10 were collected within the

contaminated fill soils. The highest level of cyanide detected was 59.9 mg/Kg.

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DRAFT FINAL

Lagoon 2

The lateral distribution of cadmium and zinc reveals that both surface and subsurface

soils in the former lagoon and its embankments have been impacted. Cadmium

concentrations ranged from 8 to 733 mg/Kg, with the highest levels detected in the

southeastern and northwestern corners of the former lagoon.

High concentrations of cadmium and zinc were found within 0 to 6 feet below ground

surface in the embankment area soils. Within the formerly remediated and filled

portion of the Lagoon 2 Area, concentrations generally decreased with depth below

the fill. High concentrations of target metals were encountered in the shallow

subsurface soil beneath the fill. In general, metals concentrations decreased to lower

or non-detection concentrations within 0 to 2-feet depth below the fill, although high

target metal concentrations were found at several sampling locations, in subsurface

soils up to 8 feet below the fill.

Detectable concentrations of cyanide were found in eight of eleven soil samples with

the 74.6 mg/Kg the highest level detected.

Lagoons 3 and 4

Cadmium concentrations detected ranged between 6 and 1277 mg/Kg, with the

highest concentration detected in shallow subsurface soils located beneath the clean

fill. This concentration is one of the two highest levels of cadmium found anywhere

within the NHPC property.

High concentrations of the target metals were also detected in the embankment

surface soils. High concentrations of target metals in the soil berm that separates

Lagoons 3 and 4 from the Northern Wetland reveals that overflow of lagoon effluent

occurred between Lagoon 3 and 4 and the Northern Wetland.

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DRAFT FINAL

Metals were detected predominantly at shallow depths in both the embankment and

interior of the Lagoon 3 and 4 Area.

Cyanide concentrations were found in 11 of the 20 soil samples. The highest level

of cyanide detected was 247 mg/Kg.

Lagoon 4 Overflow Area

Surface soils in the southwestern corner and along the western side of the overflow

area have been impacted by metals from NHPC waste disposal operations. Only

locations immediately adjacent to the former lagoon areas contain high concentrations

of metals in the surface soils. In the overflow area, metals concentrations decrease

to lower or non-detectable concentrations below 1 foot depth.

Detection of cyanide in samples analyzed from the Lagoon 4 Overflow Area

corresponded with high levels of zinc and cadmium. The highest level of cyanide

detected was 10.4 mg/Kg.

Wetlands Areas

The Southern and Northern Wetlands were not part of the original lagoon system, and

were not remediated during the EPA ERT removal action.

Southern Wetland Area

Overflow from the former NHPC lagoon system has impacted surface and shallow

subsurface soils throughout the Southern Wetland Area. High concentrations of

metals in the surface soils along the western edge of the wetland also indicates that

past vehicle decontamination activities in this area may have contributed to the area's

metals contamination.

W94619DF ES-11

DRAFT FINAL

High concentrations of cadmium and zinc were found in surface soils within the

Southern Wetland Area, with cadmium concentrations ranging from 12 to 728 mg/Kg.

The highest cadmium concentrations were detected in surface soils in the eastern and

northern portions of the wetland. Sample locations along the northern side of the

wetland and within the roadway area also indicated high concentrations of cadmium

and zinc in the soils beneath the crushed stone fill.

Other target metals detected were not widespread except for chromium and tin.

Cadmium and zinc decreased to lower concentrations at depths greater than 4 feet

below ground surface for most of the soil boring locations in the wetland area.

Cyanide was detected in seven of ten soil samples collected, with the highest level

of 509 mg/Kg. This surface soil sample contained the highest detected level of

cyanide anywhere within the NHPC property.

Northern Wetland Area

Overflow effluent from the former NHPC lagoon system delivered metals to shallow

subsurface soils throughout the area. Cadmium concentrations ranged from 7 to 286

mg/Kg, all in surface soil.

The high concentrations of cadmium and zinc detected at the berm surface and at

locations throughout the Northern Wetland Area indicate that lagoon effluent

overflowed into the Northern Wetland from the Lagoon 3 and 4 Area. The surface

water likely provided a pathway for the metals to reach areas in the central and

eastern portions of the area.

Cyanide was detected in 9 of 12 soil samples. The highest level of cyanide detected

was 21.5 mg/Kg.

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DRAFT FINAL

E.3.2 Extent of Contamination in Groundwater

Eight VOCs were detected in groundwater at concentrations above the Maximum

Contaminant Levels (MCLs) established by federal regulation. These include

trichloroethylene (TCE); 1,1-dichIoroethene (DCE); tetrachloroethylene (PCE); vinyl

chloride (VC); 1,1,1 -trichloroethane (TCA); cis & trans-1,2-dichloroethene (C&T DCE);

1,2-dichloroethane (1,2-DCA); and chloroform. Five metals were also detected in the

groundwater above the established MCLs, including cadmium, nickel, chromium,

arsenic, and lead. No samples collected in December 1993 contained elevated

cyanide concentrations. TCE and cadmium were the contaminants that most

frequently exceeded their respective MCLs of 5 ug/L.

Groundwater contamination was detected in all three aquifers. However, the levels

of contamination in the deep overburden were significantly less than in the shallow

overburden; similarly the bedrock aquifer exhibited lower levels of contamination than

found in the deep overburden. Metals contamination did not extend below the

shallow overburden aquifer. The following paragraphs characterize the extent of

groundwater contamination by aquifer.

Shallow Overburden Aquifer

Two VOCs (TCE and DCE) were detected above their MCLs within the northern half

of the YMCA property south of the NHPC Operations Area; six VOCs (TCE, DCE, PCE,

TCA, C&T DCE and VC) were detected above their MCLs within the NHPC Operations

Area, and five VOCs (TCE, DCE, PCE, TCA, and VC) were detected above their MCLs

downgradient of the NHPC Operations Area. The highest level of VOC contamination

(7500 ug/L of TCE) was found at well MW-217S, within the NHPC Operations Area,

immediately adjacent to Lagoon 1. VOC levels decrease with distance from the

Lagoon 1 source area.

One well located on the western side of the YMCA property indicated cadmium

exceeding MCLs. Twelve wells in the NHPC Operations Area indicated elevated

W94619DF ES-13

DRAFT FINAL

concentrations of cadmium, nickel, arsenic, lead, and chromium. Samples from seven

monitoring wells located in the downgradient portions of the NHPC study area

indicated cadmium, nickel, and chromium at elevated concentrations. The highest

level of metals contamination (852 ug/L of cadmium) was found at well OHM-3, on

the JCI property immediately downgradient of Lagoon 1.

Deep Overburden Aquifer

Two deep overburden monitoring wells within the YMCA property south of the NHPC

Operations Area indicated TCE, the only VOC detected in these wells, at

concentrations in exceedence of MCLs. Monitoring well MW-106, located adjacent

to Horseshoe Pond on the southern portion of the YMCA property had the highest

concentration of TCE (220 ug/L) observed in the deep overburden aquifer within the

NHPC study area. Four deep overburden monitoring wells in the NHPC Operations

Area indicated VOC concentrations exceeding MCLs. TCE and chloroform were the

only VOCs detected at elevated concentrations from these wells. Five of six wells

downgradient of the NHPC Operations Area revealed TCE and C&T-DCE at levels

above MCLs.

None of the deep overburden aquifer wells yielded groundwater samples with metals

exceeding MCLs.

Bedrock Aquifer

One VOC (TCE at 180 ug/L) was detected above its MCL in well MW-106R, adjacent

to Horseshoe Pond on the south side of the YMCA property. TCE was also detected

at elevated concentrations from bedrock wells within the NHPC Operations Area. The

results of the chemical analyses for three wells downgradient of the NHPC Operations

Area indicated the presence of TCE above its MCL in only one of them.

None of the bedrock aquifer wells yielded groundwater samples with metals exceeding

MCLs.

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DRAFT FINAL

E.3.3 Extent of Contamination in Surface Water and Sediments

Horseshoe Pond

VOCs were not detected in any of the surface water samples, however, they were

detected in five of the seven sediment samples. Four VOCs were detected in these

samples including: 2-butanone (methyl ethyl ketone (MEK)); acetone; 1,1,1

trichloroethylene (TCA); and carbon disulfide.

The only sediment sample subjected to SVOC analysis, which was collected on the

eastern shore adjacent to the NEPWTC property, indicated the presence of several

polynuclear aromatic hydrocarbons (PAHs) typically associated with fuels, oils, and

other petroleum-related compounds. One phthalate was also detected in the sample.

Arsenic, cadmium, chromium, copper, lead, nickel and zinc were not observed above

method detection limits in any of the seven surface water samples analyzed for total

metals or filtered metals. Cyanide also was not observed above detection levels in

surface water or sediment samples.

Sediment samples containing arsenic, chromium, copper, nickel, and zinc were

detected at concentrations above background levels.

Merrimack River

VOCs were not detected at concentrations above detection limits in any of the surface

water or sediment samples.

No identified site metals were detected for total metals, or filtered metals. Cyanide

was also not detected in the surface water.

W94619DF ES-15

E.4

DRAFT FINAL

Contaminant Fate and Transport

Activities conducted at the NHPC facility have resulted in contaminants being located

principally in three areas, which include the former lagoons, the former building area,

and downgradient areas.

Lagoon System

Within the former lagoon system and adjacent overflow areas, contaminants are

present in soil. Metals and cyanide have been detected in surface and subsurface

soils above the water table. Transport of these metals and cyanide within the lagoon

areas occurs by three primary mechanisms:

• Entrainment of contaminated soil particles in surface runoff;

• Percolation of infiltrating precipitation and surface water through

contaminated soils to the water table; and

• Direct contact between groundwater and stockpiled soil below the water

table in the Lagoon 1 Area and subsequent desorption of contaminants

from the soil.

Transport as surface water runoff occurs as rainwater and snow melt flows overland

and collects in the low-lying lagoons areas. Cadmium, zinc, and other metals were

detected in samples from the lagoon area embankments, which will be a continuing

source for contaminant migration by surface runoff unless they are covered or

otherwise remediated.

Surface water collects in the lagoon areas and recharges the underlying aquifer (water

flows uniformly downward to the water table in the lagoons; upward flow does not

occur). Consequently, metals in lagoon area soils are slowly leaching into the

underlying aquifer.

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DRAFT FINAL

Contaminants then travel with groundwater to downgradient areas. These

downgradient areas, east and southeast of the NHPC property, contain elevated

concentrations of several metals, including cadmium. Among the heavy metals,

cadmium is relatively mobile and will tend to leach into groundwater more rapidly than

other metals. The contaminated soils act as a continuing source of groundwater

contamination as the adsorbed metal slowly leaches away.

VOC contamination has also been identified in the aquifer below the lagoon area, with

MCL exceedences found for TCE; PCE; 1,1 -DCE; 1,1,1-TCA; 1,2-DCA; and vinyl

chloride. It is likely that these VOCs are adsorbed to soils beneath the water table in

the Lagoon 1 Area, and are being desorbed from the soil to groundwater.

Former Building Area

Potential source areas include soil near the building septic system leachfield, soil near

a former 275-gallon above ground storage tank, soil beneath a waste collection trench

formerly in the NHPC building, and soil near the former opening in the wall of the

NHPC building that served as an overflow outlet during periods of high waste

discharge. The levels of contamination in these areas, however, are substantially

lower than in the lagoon system.

Transport of contaminants in the building area via surface water runoff is minimized

by the presence of pavement, and a cover over the former building. Percolation of

infiltrating precipitation and surface water through contaminated soils to the water

table is also minimized due to these covers. Therefore, the former building area no

longer serves as a significant continuing source of contamination.

Contamination historically originating from the building is, however, present in

groundwater, and is transported by groundwater to downgradient areas. East of the

building area, peak concentrations of cadmium and chromium were noted

downgradient of the former plating waste collection trench at the building overflow

outlet. The relatively lower metals concentrations closer to the former building area

W94619DF ES-17

E.5

DRAFT FINAL

appear to reflect the higher rates of recharge to the water table that occurred during

plant operation and the subsequent downgradient migration of the cadmium plume.

Downgradient Areas

Many of the contaminants found in soils and groundwater at the site are mobile.

VOCs and elevated metals concentrations were detected in groundwater

downgradient of the lagoons and former building area. In general, these contaminants

are being transported through advective flow in the groundwater toward the

Merrimack River. Contaminant diffusion and dispersion results in the typical

broadening of the contaminant plumes with distance from the source. Most

contaminant transport with groundwater occurs in the shallow aquifer.

The approximate distance between the cadmium source area and the groundwater

plume peak cadmium concentration was used to estimate the rate of contaminant

travel. Contaminants in groundwater have traveled approximately 300 feet

downgradient of the source since facility shutdown. The fate of contaminants from

the site travelling with groundwater appears to be the Merrimack River. Contaminants

discharging to the river are apparently diluted to levels below detection.

Human Health Risk Assessment

The following bullets summarize the results of the baseline human health risk

assessment conducted for the NHPC study area:

• Chemicals of concern in groundwater include TCE, DCE, PCE, VC, TCA,

C&T DCE, 1,2-DCA, chloroform, arsenic, cadmium, chromium, and

nickel. A comparison of contaminants of concern concentrations to

available MCLs indicates that the aquifer underlying and downgradient

of the site is not suitable as a potable water supply.

W94619DF ES-18

DRAFT FINAL

• If the aquifer underlying and downgradient of the NHPC Operations Area

is utilized as a domestic water supply in the future, risk estimates exceed

the U.S. EPA 10~4 to 10"6 cancer risk range often used to determine the

need for action at a CERCLA site. Cancer risk estimates for individual

COCs such as TCE also exceed 104.

• A potential for adverse noncarcinogenic health effects exists to

individuals exposed to the groundwater contaminants in the aquifer -5,5. -=«—IS"*— _ -ai •&£:£- -"J- -W.

underlying and downgradient of the study area.

• Cancer risk estimates for soils from the lagoon system, the former

building area, and adjoining areas are within or less than the EPA target

range of 1 x 10"4 to 1 x 10'6.

• The potential for adverse noncarcinogenic health effects exists only if

receptors are exposed under reasonable maximum exposure conditions.

• Lead concentrations in soil samples from Lagoon 2 and the Southern

Wetland exceed an EPA Benchmark of 1,000 ppm (a benchmark for lead

in industrial soil).

• Dermal contact with or inadvertent ingestion of the sediments of

Horseshoe Pond and/or the Merrimack River by a recreational user does

not appear to present significant risk.

Ecological Assessment

The ecological risk assessment only addressed the soil exposure pathway for the

wetlands-lagoons system as a whole. Cadmium was selected as the indicator

contaminant of concern. The potential ecological risks associated with the former

NHPC building area were not addressed because this area offers minimal wildlife

habitat, and thus represents an incomplete contaminant exposure pathway. The

W94619DF ES-19

E.6

DRAFT FINAL

potential ecological risks associated with the Merrimack River and Horseshoe Pond

surface water and sediment exposure pathways were not addressed in the ecological

risk assessment because few site-related contaminants were detected there and

because contaminant sources other than the NHPC site can potentially introduce

contaminants to these surface water bodies. The following bullets summarize the

results of the ecological risk assessment:

• The ecological risk assessment concluded that the lagoon system portion

of the NHPC property presents an unacceptable risk to ecological

receptors because cadmium soil contamination could cause detrimental

effects on populations of organisms and the overall food web associated

with the site.

• Four indicator species were selected for the ecological risk assessment,

and a conceptual food web model was prepared to represent the soil

exposure pathway at the site. The food web model was the basis for

the calculation of cadmium soil concentrations above which adverse

effects on the indicator species are expected to occur.

• Of the four indicator species, the short-tailed shrew was found to be at

the greatest risk of adverse effects from cadmium concentrations in the

soil. For this indicator species, cadmium soil concentrations above 5.6

mg/Kg would be expected to cause detrimental impact.

E.7 Conclusions

Surface and subsurface soil within the NHPC lagoon system and the former building

area is contaminated with site-related metals, the most significant of which is

cadmium. Levels of cadmium range up to 1277 mg/Kg, and are higher in the lagoon

system than in the former building area. The levels of contamination in lagoon system

soil present a significant direct risk to ecological receptors. The levels of

contamination in site soils present a noncarcinogenic human health risk only when the

W94619DF ES-20

DRAFT FINAL

reasonable maximum exposure scenario is considered. The more significant human

health risk posed by the contaminants in soils is the indirect risk caused by the

continued leaching of contaminants to groundwater.

Groundwater beneath and downgradient of the NHPC Operations Area is contaminated

with site-related organic and inorganic contaminants. The majority of the groundwater

contaminants (chlorinated organics and metals) were found in the shallow overburden

aquifer that lies beneath the site, and above the identified lower permeability glacio

lacustrine soil unit. Only five chlorinated organic contaminants were found in the

lower overburden aquifer (below the glacio-lacustrine unit) and even fewer chlorinated

organic contaminants were detected in bedrock. The highest levels of groundwater

contamination are present below and just downgradient of Lagoon 1. An additional

area of contamination also exists south of the former building area, on the YMCA

property.

Based on water level measurements and contaminant distribution, the contamination

from the site is migrating with groundwater to the east and southeast toward the

Merrimack River. Surface water and sediment sampling do not indicate that the river

is being impacted, and the contaminants are likely being diluted below detection

levels.

Twelve contaminants are present in groundwater at levels that exceed their respective

MCLs. If groundwater were to be used as a domestic water supply, the groundwater

contaminants would present carcinogenic and noncarcinogenic risks to human health.

Because the NHPC Site poses both ecological and human health risks, a Feasibility

Study (FS) is recommended to address the contamination detected in soils and

groundwater.

W94619DF ES-21

ACGIH

AOC

ATSDR

AWQC

B & M

BAF

BEI

BEPH

BTEX

C & T DCE

CEC

CERCLA

CLP

CNS

COC

CSF

CT

DCA

DCE

W94619DF

DRAFT FINAL

LIST OF ACRONYMS AND ABBREVIATIONS

American Conference of Governmental Industrial Hygienists

Area of Concern

Agency for Toxic Substances and Disease Registry

Ambient Water Quality Criteria

Boston and Maine

Bioaccumulation Factor

Badger Environmental Inc.

bis(2-ethylhexyl)phthalate

Benzene, Toluene, Ethylbenzene and Xylenes

Cis and Trans - 1,2-dichloroethene

Cation Exchange Capacity

Comprehensive Environmental Response Compensation and Liability Act

Contract Laboratory Program

Central Nervous System

Contaminant of Concern

Carcinogenic Slope Factor

Central Tendency

1,1 -Dichloroethane

1,1-Dichloroethene

-1

DRAFT FINAL

LIST OF ACRONYMS AND ABBREVIATIONS (Continued)

DDT 4,4'-Dichlorodiphenyltrichloroethane

%DI Percent Dietary Intake

DQO Data Quality Objectives

ECG Electrocardiograph

EE/CA Engineering Evaluation / Cost Analysis

EPA Environmental Protection Agency

EPRB Emergency Planning and Response Branch

ERL-C EPA Environmental Research Laboratory - Corvallis

ERT Emergency Response Team

F Degree Fahrenheit

FFS Focused Feasability Study

FS Feasability Study

GC Gas Chromatograph

Gl Gastrointestinal

GZA Goldberg Zoino and Associates, Inc.

HA Health Advisory

HDP High Density Polyethylene

HI Hazard Index

HNUS Halliburton NUS Corporation

HQ Hazard Quotient

IRIS Integrated Risk Information System

I.D. Inside Diameter

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DRAFT FINAL

LIST OF ACRONYMS AND ABBREVIATIONS (Continued)

ICP Inductively Coupled Plasma

JCI Jones Chemical Inc.

LEI Ludgate Engineering Inc.

LOAEL Lowest Observed Adverse Effect Level

LOEL Lowest Observed Effect Level

MCL Maximum Contaminant Level

MCLG Maximum Contaminant Level Goal

MEK Methyl Ethyl Ketone

mg/Kg milligram per kilogram

mg/L milligram per liter

MLMC Magnum Leasing and Mortgage Company

mph miles per hour

MTBE Methyl-tertbutyl ether

MVWD Merrimack Village Water District

NCR National Oil and Hazardous Substances Pollution Contingency Plan

NEPWTC New England Pole and Wood Treating Company

NERL Northeast Regional Laboratory

NHDES New Hampshire Department of Environmental Services

NHPC New Hampshire Plating Company

NOEL No Observed Effect Level

NOV/OOA Notice of Violation/Order of Abatement

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DRAFT FINAL

LIST OF ACRONYMS AND ABBREVIATIONS (Continued)

NTCRA Non-Time-Critical Removal Action

NTU Nephelometric Turbidity Unit

NUS FIT NUS Corporation Field Investigation Team

ORD Office of Research and Development

PA Preliminary Assessment

PAH Polynuclear Aromatic Hydrocarbons

PCB Polychlorinated biphenyl

PCE tetrachloroethene

pH Hydrogen ion concentration

PID Photo-ionization detector

PVD Polyvinyl chloride

ppm parts per million

QA/QC Quality Assurance / Quality Control

RAS Routine Analytical Services

RCRA Resource and Conservation Recovery Act

REC Raytheon Engineers and Constructors, Inc.

REAC Response Engineering and Analytical Contractor

RfC Reference Concentration

RfD Reference Dose

Rl Remedial Investigation

RME Reasonable Maximum Exposure

ROD Record of Decision

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DRAFT FINAL

LIST OF ACRONYMS AND ABBREVIATIONS (Continued)

Rp Rippowan

RREL Risk Reduction Engineering Laboratory

SARA Superfund Amendments and Reauthorization Act

SAS Special Analytical Services

SDWA Safe Drinking Water Act

SFF Site Foraging Frequency

SNHWC Southern New Hampshire Water Company

STMSC Solidified Treated Material Storage Cell

SVOC Semivolatile Organic Compound

UF Uncertainty Factor

USCS Unified Soil Classification System

USEPA United States Environmental Protection Agency

USFWS United States Fish and Wildlife Service

USGS United States Geological Survey

TAT Technical Assistance Team

TCA 1,1,1-Trichloroethane

TCB 3,3',4,4'-Tetrachlorobiphenyl

TCE Trichloroethene

TCLP Toxicity Characteristic Leaching Protocol

T-DCE trans-Dichloroethene

TOC Total Organic Carbon

TPH Total Petroleum Hydrocarbon

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DRAFT FINAL

LIST OF ACRONYMS AND ABBREVIATIONS (Continued)

TSD Transportation, Storage and Disposal

TVOC Total Volatile Organic Compound

ug/Kg microgram per kilogram

ug/L microgram per liter

UST Underground Storage Tank

VC Vinyl Chloride

VOC Volatile Organic Compound

WLS Wetlands-Lagoon System

XRF X-Ray Fluorescence

W94619DF -6

1.0

DRAFT FINAL

INTRODUCTION

Halliburton NUS Corporation (HNUS) and Raytheon Engineers and Constructors, Inc.

(REC), (formerly Badger Engineers, Inc.) were contracted by the United States

Environmental Protection Agency (EPA) to perform a Remedial Investigation (Rl) of the

New Hampshire Plating Company (NHPC) Site in Merrimack, New Hampshire. This

investigation was authorized by the EPA under Work Assignment No. 33-1GL1,

Contract No. 68-W8-0117.

In an effort to accelerate the decision-making process, without dividing the site into

operable units, a detailed evaluation of the former NHPC building was conducted

concurrent with the Rl. This evaluation included the performance of a Focused

Feasibility Study (FFS) and Engineering Evaluation/Cost Analysis (EE/CA) for the

building. The building subsequently was demolished and removed as a Non-Time-

Critical Removal Action (NTCRA). Results of the FFS and EE/CA for the former NHPC

building are documented separately in the April 1993 "Draft Focused Feasibility

Study" and October 1993 "Engineering Evaluation/Cost Analysis for Non-Time-Critical

Removal Action" prepared by HNUS/REC.

This report presents the results of the Rl. The source, nature and extent, fate and

transport of contaminants, and ecological and human health risks are addressed in this

report. Recommendations for future work and remedial action objectives for the site

are also presented. With completion of this Rl, a Feasibility Study (FS) will be

undertaken to evaluate remedial alternatives for the entire site. A Record of Decision

(ROD) outlining the selected remedy for the site will follow.

The overall objective of the RI/FS is to characterize the risks posed by hazardous

substances at the site and to evaluate potential remedial options. To achieve this

objective, the RI/FS must:

• assess the source, nature, and distribution of contaminants in

groundwater, soils, surface water, and sediments;

W94619DF 1-1

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DRAFT FINAL

• assess the fate and transport of these contaminants;

• evaluate through a risk assessment the potential threats to human health

and the environment posed by site contamination; and

• develop and evaluate a range of remedial alternatives that address the

site contamination.

The Rl was performed consistent with requirements outlined in the Comprehensive

Environmental Response Compensation and Liability Act (CERCLA) of 1980 and

Superfund Amendments and Reauthorization Act (SARA) of 1986, the National Oil

and Hazardous Substances Pollution Contingency Plan (NCP), and the EPA Statement

of Work for the NHPC Site (1992).

The Rl report was prepared in accordance with the Interim Final Guidance for

Conducting Remedial Investigations and Feasibility Studies Under CERCLA (EPA,

October 1988). The report organization is presented in Section 1.2.

Site and Study Area Background

A description of the NHPC site and study area, including the site history, is presented

in this section. The approximately 13 acre NHPC site is located in the Town of

Merrimack (Hillsborough County) in south central New Hampshire. The site is located

on the northern side of Wright Avenue approximately one quarter of a mile east of the

Daniel Webster Highway (Route 3), as shown on Figure 1 -1, Site Location Map. This

area is zoned for commercial and light industrial use, although residential lots, both

developed and undeveloped, are found to the north, south, and west. The site is

situated between three major water bodies, which include the Souhegan River (located

approximately 1200 feet north of the site), the Merrimack River (located

approximately 500 feet east of the site), and Horseshoe Pond (located approximately

600 feet south of the site).

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DRAFT FINAL

As shown on Figure 1-2, Study Area Location Map, the NHPC study area is comprised

of several parcels of land that include the NHPC site, adjacent properties, and other

areas located to the south, east, and west. These other areas include the Magnum

Leasing and Mortgage Company property, the City of Manchester YMCA property,

Horseshoe Pond Island, the New England Pole and Wood Treating Company

(NEPWTC) property, Lot Number 22 property, the Techwood Building Systems, Inc.

(Techwood) property, and the Jones Chemical, Inc. (JCI) property. Descriptions of

these study area parcels are provided in Section 2.0.

NHPC Site History

NHPC operated an electroplating facility on the site from 1962 to 1985. The metals

used in the electroplating process included cadmium, zinc, chromium, copper, lead,

nickel, tin, gold, silver, aluminum, iron, and manganese. The chlorinated organic

solvents used included trichloroethylene, 1,1,1-trichloroethane, and

tetrachloroethylene. Cyanide was also used in the electroplating process. Chlorinated

solvent use was reportedly discontinued during the latter part of the 1970s.

Electroplating wastes generated by the NHPC facility included metals, volatile organic

compounds (VOCs), cyanide, and acids (Weston, 19901).

Treated and untreated wastes and wastewater were collected within various drainage

trenches constructed in the concrete floors of the former NHPC building's processing

areas. The wastes were then gravity-drained through an underground discharge pipe

to the unlined waste lagoons located approximately 325 feet north of the building.

Wastes were discharged directly into a primary infiltration lagoon (Lagoon 1). The

lagoon system was constructed to allow the discharged wastes to flow from the

primary lagoon into a secondary infiltration lagoon (Lagoon 2) and subsequent

overflow lagoons (Lagoons 3 and 4) during periods of high discharge from the facility.

Approximately 35,000 to 60,000 gallons of wastewater were generated and

discharged to the lagoons each day (Bracchi, 1992).

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DRAFT FINAL

In 1980, NHPC notified the U.S. Environmental Protection Agency (EPA) that it was

a hazardous waste disposal facility according to the Resource and Conservation

Recovery Act (RCRA) Section 3001 regulations. The first RCRA inspection in 1982

resulted in the issuance of a Notice of Violat