Volume I - Text
Transcript of Volume I - Text
PHASE 1A .' "" >SITE CHARACTERIZATION REPORT V ~
Volume I - Text
Remedial InvestigationBarkhamsted-New HartfordLandfill Superfund SiteBarkhamsted, Connecticut
Barkhamsted Site PRP Group
April 1993
OBRIENCGEREENGINEERS, INC.
TABLE OF CONTENTS (Continued)
Page
16 Geologic Cross Section B-B1 - Area B & C 17 Test Pit Location and Limits of Refuse Map 18 Ground Water Investigation Map 19 Schematic of Pneumatic Packer Test Equipment 20 Geologic Cross Section C-C1
21 Geologic Cross Section D-D1
22 Overburden Ground Water Elevation Map - January 26, 1993 23 Shallow Bedrock Ground Water Elevation Map - January 26, 1993 24 Intermediate Bedrock Ground Water Elevation Map - January 26, 1993 25 Deep Bedrock Ground Water Elevation Map - January 26, 1993 26 Semi-Quantitative Flow Net E-E1
27 Semi-Quantitative Flow Net F-F1
28 Overburden Ground Water Plume Map - Total VOCs 29 Shallow Bedrock Ground Water Plume Map - Total VOCs 30 Intermediate Bedrock Ground Water Plume Map - Total VOCs 31 Deep Bedrock Ground Water Quality - Total VOCs 32 Ground Water User Survey and Domestic Supply Well Sample Locations 33 Air Sample Location Map 34 Surface Water/Sediment and Leachate Seep Sample Locations 35 Covertype Map 36 National Wetland Inventory Map for the Vicinity of the Site 37 Litchfield County Soil Survey Map 38 Wetland Delineation Map 39 Floodplain Boundary Map
APPENDICES
A Wetland Delineation Report B Resistivity Plots C Grain Size Analysis Results D Soil Boring and Monitoring Well Logs E Hydraulic Conductivity Data and Plots F Ground Water Sampling Logs G Ground Water User Survey Form H Ground Water Analysis Survey Results I Air Particulate DataLogger Results J On-Site Meteorological Station Data K Brady International Airport Meteorological Data L Air Sampling Survey Data Sheets M Wetland Function and Value Assessment Report
DRAFT April 29, 1993
SECTION 1 - INTRODUCTION
1.01 Introduction
The Barkhamsted-New Hartford Landfill Superfund Site (Barkhamsted Site) is
located adjacent to and southwest of Route 44 within the Towns of Barkhamsted and
New Hartford, Connecticut as shown on Figure 1. The landfill, owned and operated
by Regional Refuse Disposal District #1 (RRDD #1), has been used for solid waste
disposal since April 1974 under a Solid Waste Permit (#005-2L) from the Connecticut
Department of Environmental Protection (CTDEP) for operation of a sanitary landfill.
In 1981, the United States Environmental Protection Agency (USEPA)
conducted a Preliminary Assessment for the Barkhamsted Site based on the results of
a 1980 CTDEP inspection. The USEPA recommended that a site inspection be
conducted. The USEPA site inspection was performed in 1987.
Pursuant to Section 105(8)(b) of the Comprehensive Environmental Response,
Compensation and Liability Act (CERCLA), the Barkhamsted Site was proposed for
inclusion on the National Priorities List (NPL) on June 21, 1988 (53 FR 23988). The
Barkhamsted Site was listed on the NPL on October 4, 1989 (NPL final rule update #6,
54 FR 41015). An Administrative Order to conduct a Remedial Investigation/Feasibility
Study (RI/FS) at the Barkhamsted Site between the Barkhamsted Site PRP Group, the
State of Connecticut and the USEPA became effective on October 4, 1991. (Docket
No. 1-91-1128, October 4, 1991).
During December 1991 and January 1992, O'Brien & Gere Engineers, Inc.
performed a Limited Field Investigation (LFI) at the Barkhamsted Site pursuant to an
LFI Work Plan approved by the USEPA in December 1991. The purpose of the LFI
DRAFT 1 April 29, 1993
was to produce a focused Work Plan for the RI. The results of the LFI are presented
in the Remedial Investigation Work Plan, which received conditional approval from the
USEPA effective October 1, 1992.
Fuss & O'Neill prepared and implemented a Scope of Study at the Barkhamsted
Site on behalf of RRDD #1. The objective of the Scope of Study was to satisfy the
requirements of the CTDEP Administrative Order No. 666. This Administrative Order
required RRDD #1 to: 1) investigate the waste materials and disposal activities on-site,
2) determine the potential impact of such activities or such waste on human health both
on-site and off-site, 3) determine the existing and potential extent and degree of soil,
ground water, and surface water pollution, and 4) identify potential impacts of polluted
ground water and surface water on public and private drinking water supplies. The
results of that investigation are summarized in the Remedial Investigation Work Plan
presented in the RRDD #1 Landfill Site Investigation Report, Fuss & O'Neill,
December 1991.
The majority of field work conducted pursuant to the approved Remedial
Investigation Work Plan was performed between October 1992 and January 1993. The
results of this work are presented in this Phase 1A Initial Site Characterization Report.
Remaining work to be completed in connection with the USEPA approved work plan
includes second round sampling and analysis of surface water/sediments and ground
water. In accordance with the approved Remedial Investigation Work Plan, the results
of these efforts will be presented in an addendum to this report.
DRAFT 2 April 29, 1993
1.02 Rl Objectives
As presented in Section 1 of the Statement of Work (SOW), the primary
objective of the RI/FS is to assess site conditions and evaluate alternatives to the extent
necessary to select a remedy of the site as defined in the Administrative Order on
Consent. The objectives of the RJ are to:
1. Define the source(s), nature, extent, and distribution of contaminants
released;
2. Evaluate and quantify potential exposure pathways;
3. Provide sufficient information to assess the risks to human health and to
the environment; and
4. Provide sufficient information to evaluate remedial alternatives,
conceptually design remedial actions, select a remedy, and issue a record
of decision.
The Phase 1A Initial Site Characterization represents the principal component
of the RI.
1.03 Purpose and Objectives of Phase 1A Initial Site Characterization
As presented in Section 3 of the SOW, the objective of the Initial Site
Characterization (conducted in accordance with the approved Work Plan during the
Phase 1A Field Investigations) was to conduct field activities and collect field data for
the RI/FS. Information generated during the Phase 1A Initial Site Characterization is
to be utilized to select a remedy and to further define the boundaries of the RI/FS study
area by identifying and characterizing all source areas and determining the extent of
existing contaminants and of environmental effects resulting from releases from the site.
DRAFT 3 April 29, 1993
The Site Characterization will provide information sufficient to refine preliminary
identification of potentially feasible remedial technologies and potential Applicable or
Relevant and Appropriate Requirements (ARARs). The Site Characterization will also
provide data needed by the USEPA to perform a Baseline Risk Assessment.
DRAFT 4 April 29, 1993
SECTION 2 - STUDY AREA DESCRIPTION
2.01 Introduction
The Barkhamsted Site is located on lands of RRDD #1 adjacent to and southwest
of Route 44 within the Towns of Barkhamsted and New Hartford, Connecticut as
shown on Figure 1. The Barkhamsted Site is on a 97.8 acre parcel of land on the
northern slope of a hill within the Farmington River Valley in the north central portion
of Connecticut, approximately 20 miles northwest of Hartford. The RRDD #1 property
:i is bordered to the northeast by the Barkhamsted Town Garage facility. The remainder
i> of the parcel is bounded by a combination of developed and undeveloped private
property. Landfill operations occur on a area located in the northern area of the property
with refuse overlaying approximately 10.2 acres of this area. The landfill disposal area
extends north to the RRDD #1 boundary, west to the Unnamed Brook which bisects the
RRDD #1 property, east to the landfill access road and south to a drainage ditch
constructed along the Barkhamsted-New Hartford town line (Figure 2).
i
2.02 Study Area Background
1 The Barkhamsted Site was utilized for the disposal of solid waste between April
1974 and August 1988. Since August 1988, the landfill has been utilized only for the
- disposal of bulky and non-processible waste with the exception of a period during
November and December 1988 when the CRRA Mid-Connecticut Waste to Energy
Plant was inoperable. Recycling activities have been conducted at the site since it was
opened.
DRAFT 5 April 29, 1993
RRDD#1 was formed in May 1970 by the communities of Barkhamsted,
Colebrook, New Hartford, and Winchester. On September 21, 1972, RRDD#1 received
CTDEP solid waste permit #005-2L based on plans prepared by W.G. Weaver and
Associates. According to these plans, landfilling was to occur in a 24.7-acre area
bounded on the west by a 50-foot buffer along the Unnamed Brook, the town line on j
the south, and the eastern portion of the railroad right of way on the east. The bulky
waste disposal area, or stump dump, was to be separated from the main disposal area.
) This area was to be north of the landfill operation building at a location which is
> currently paved between the landfill office and the transfer station. The original \i
Weaver plans also called for the construction of a fluid pit, although a location was not
specified. The plans called for the construction of terraces with a grade of two percent
to be formed by cutting the natural grade. Individual cells (with 6 inches of cover
between cells) were to be constructed on the terraces, with solid waste landfilling to be
initiated on the western side of the northern toe of the existing landfill. Cell
construction required 6 inches of cover between the cells. Filling was to proceed east
along the front of the landfill and then proceed to the south. It is not believed that this ~] - filling sequence was followed during the early years of landfill operation, but no
| documentation currently exists on specific landfilling operations. ^>
An amendment to the RRDD#1 solid waste permit was issued on January 17,
1974, following submission of a revised operation and management plan dated January
2, 1974. The amendment addressed modifications to service area and entrance road
designs as well as to the stump and brush disposal area. The amended permit required
that all wastes with the exception of stumps and brush be excluded from a 50-foot wide
DRAFT 6 April 29, 1993
zone between the Unnamed Brook and the landfill. No refuse was to be allowed to
come into contact with the Unnamed Brook.
The landfill became operational in April 1974. According to CTDEP solid
waste landfill inspection reports from the period of 1974 to 1979, problems were
> reported regarding a lack of daily cover material. Bulky wastes and brush were noted
as the wastes most frequently left uncovered. Ponding of water on the landfill surface <
was also reported to be a problem. The ponding of water is believed to have created
an increase in the amount of leachate resulting from the infiltration of water. Brush and
--, bulky waste were observed to be encroaching on the 50-foot buffer zone which had
been established between the landfill and the Unnamed Brook in the original plans for
the landfill.
In 1981, United States Environmental Protection Agency (USEPA) conducted
a preliminary assessment for the Barkhamsted Site based on a 1980 CTDEP inspection,
and recommended that a site inspection take place. USEPA conducted a site inspection
in 1987. USEPA's site inspection reported that a ground water sample collected and J
analyzed prior to the site inspection contained xylene (92 ppb), toluene (870 ppb), 1,1
-J dichloroethane (86 ppb), 4-methyl-2-pentanone (1700 ppb), and vinyl chloride (170
~] ppb)- In addition, the site inspection reported that industrial oily metal grinding sludges
disposed of at the site contained cadmium, chromium, copper, lead, manganese, nickel
ji and zinc. Leachate from the landfill was observed discharging into the Unnamed Brook
during this site inspection.
A modification to the landfill operating permit was issued on December 16, 1983
based on an updated Operation and Maintenance Plan prepared by Roger H. Whitney,
Inc. in 1982 and updated in 1983. According to this updated plan, landfilling of solid
DRAFT 7 April 29, 1993
waste was to be limited to an area bounded by the Unnamed Brook buffer on the west,
the town line on the south, the main access road on the east, and the railroad right of
way on the north. This plan also allowed for a 1,000-foot buffer zone between the
landfill and a domestic well located to the east on U.S. Route 44. Therefore, the area
available for landfilling was reduced to approximately 10 acres. The plan called for
filling to be conducted by constructing cells 9 feet high and 35 feet wide. Cell
construction was to be initiated at the northern portion of the landfill, proceeding from
] east to west with rows of cells to be constructed from north to south. The direction of
-j row construction was to be reversed following completion of the fourth lift of cells.
i On February 27, 1990, a minor amendment was granted to the RRDD#1 solid
waste permit allowing the landfill to accept dewatered sludge from the Winsted Publicly
Owned Treatment Works (POTW). The sewage sludge was brought to the site and
incorporated into the landfill cover material.
Industrial wastes, including metal grinding waste, oily sludge with metal
~j grinding and degreasers, barrels containing unspecified amounts of chlorinated
hydrocarbons and methyl-ethyl-ketone, and keratin (a food processing waste) were
- accepted at the site. Dry metal grinding waste was utilized on site roads and
1 incorporated into the landfill daily cover. CTDEP records state that an industrial waste
pit was operated at the site during the first year of landfill operation (Fuss & O'Neill,
1991b). Information on the pit location, materials placed in the pit, and its duration of
use is limited. Fuss & O'Neill reported that a 1988 CTDEP document refers to
chemical pit operation in the 1970s that received "oily sludge with metal grindings and
degreasers". A drum crushing operation was reportedly located proximal to a scrap
metal area north of the toe of the landfill and northwest of the landfill garage. The
DRAFT 8 April 29, 1993
1988 CTDEP document states that one half of the barrels received at the site contained
unspecified amounts of chlorinated hydrocarbons or methyl-ethyl-ketone. There are
also reports of the rejection of wastes, such as cutting oils, from the landfill during
1974. The time period for which the waste pit was utilized and its location are not
precisely known. Reference was made to the location of the waste pit "near the existing
n metal grinding waste cell" in 1974. Metal grinding wastes appear to have been
disposed of-at a variety of locations at the site, including north of the toe of the landfill, *~i
\ in the vicinity of a stone arch, and on roadbeds to the east of the landfill. Therefore,
-i the location of the industrial waste pit cannot be accurately identified.
) The types and quantities of industrial wastes handled at the site are not well
documented in CTDEP records. In March 1981, RRDD#1 was requested by the
CTDEP to eliminate hazardous waste from the facility. In July 1981, the CTDEP
formally approved metal grinding waste for disposal at RRDD#1 since testing indicated
that these wastes were not characteristically hazardous. The CTDEP stipulated that the
metal grinding wastes be kept separate from other refuse. A cell for metal grinding
wastes was specified in the operational plans originally prepared by Roger H. Whitney, 1
Inc. in 1982. This cell was to be constructed at the southern portion of the landfill,
I and metal grindings which had been deposited on an unnamed access road on the
eastern portion of the site were scheduled to be relocated to this cell. The cover
material in the metal grinding cell was to consist of a soil-lime mixture in order to raise
the pH and minimize metal leaching to the subsurface. The plan also proposed that the
metal grinding wastes be mixed with cover materials in the cells due to the
nonhazardous nature of these materials. A new metal grindings cell was required by
the middle of 1984. At that time, some metal grindings were apparently stored on-site
DRAFT 9 April 29, 1993
in 55-gallon drums. Existing documents report that the metal grinding waste was
~~ sometimes received heated and placed in piles exceeding 10 feet in height.
In 1983, two complaints were received concerning the presence of a large
number of drums at the landfill. The first complaint, in April 1983, resulted in CTDEP
requesting that 25 drums, which reportedly contained used motor oil, be relocated from /
the vicinity of the oak tree northwest of the landfill building to a paved area on-site.
Fuss & O'Neill reported that the CTDEP collected a composite sample from the drums. 1
j The sample reportedly exhibited a low flashpoint (77°C) and relatively high levels of
lead and cadmium. In November 1983, at least 30 drums were found proximal to the
scrap metal area north of the toe of the landfill and northwest of landfill garage. These
drums were scheduled for crushing, an operation which was apparently centered in this
area of the site. Following investigation into this complaint, the CTDEP formally
notified RRDD#1 that the landfill could not accept hazardous materials for storage or
disposal. The landfill, however, has accepted waste oil for recycling throughout its
operation. Handling of both waste oil and batteries for recycling was reported to and >
it acknowledged by the CTDEP in September 1986.
Presently, the landfill has an active working area of approximately 17 acres, with
1 refuse overlying an area slightly greater than 13 acres. The remaining acreage is utilized
for recycling, offices and other ancillary landfill activities. It is currently open to the
-J public for the disposal of bulky wastes which include construction and demolition
debris. A recycling collection station is operated on-site and is utilized for collecting
glass, plastic, paper, metal, waste oil and paint. Appliances such as refrigerators and
washing machines are deposited in the former drum crushing area and later disposed
DRAFT 10 April 29, 1993
of off-site. Sewage sludge is brought to the site and incorporated into the cover
material. Leaf composting is also conducted on the landfill.
Information in this section has been extracted from the December 1991 report
prepared by Fuss & O'Neill and interviews conducted with representatives of Fuss &
O'Neill. In preparing the discussion of historical waste disposal practices, Fuss &
^ O'Neill reviewed information from the following sources: I
Connecticut Department of Environmental Protection (CTDEP)
j Solid Waste Management Unit Files;
CTDEP Hazardous Waste Management Unit Files; j
CTDEP Water Compliance Division Files;
CTDEP Oil and Chemical Spills Division Files;
USEPA Superfund Files;
CTDEP Underground Storage Tank Files;
RRDD#1 Files;
Town of Barkhamsted Files; and
Personal interviews with John Raabe, PhD. (Geologic Services
-1 Geologist) and James Hart (RRDD#1 Landfill Administrator).
A more detailed discussion of waste disposal at the site may be found in the
Landfill Site Investigation (Fuss & O'Neill, 1991b).
i
2.03 Sensitive Environments and Ecosystems
An ecological characterization of the Barkhamsted Site is presented in the
Landfill Site Investigation (Fuss & O'Neill, in 1991b). O'Brien & Gere performed a
preliminary ecological assessment during December of 1991 as part of the Limited Field
DRAFT 11 April 29, 1993
Investigation (LFI), the results of which are presented in the Remedial Investigation
"" Work Plan (RI Work Plan). These investigations, along with additional work associated
with preparation of this report to assess the nature and extent of effects of site
contamination on nearby ecological resources, are presented in Section 7.
~i
j 2.04 Climatology
i The climate of Connecticut is generally temperate-humid. The proximity of the
) state to the ocean, which is the dominant factor affecting weather most of the year, has
a moderating effect on temperatures. Thermal lag of the ocean causes the spring to be
typically cool and cloudy and the summer and early fall to be warm and clear. i
Precipitation is generally plentiful and evenly distributed throughout the year. The
quantity of water received in Connecticut by precipitation is approximately twice the
quantity lost by evaporation (National Water Summary 1988-89).
1 2.05 Topography and Drainage i J
The Barkhamsted Site is located on the northern toe of a gentle north to south "1
_j sloping hill. A north to south trending ridge lies to the west at a higher elevation and
1 the floodplain of the West Branch of the Farmington River lies to the east of the y
RRDD#1 property.
-1 The floodplain of the West Branch of the Farmington River is at an elevation
of approximately 400 feet mean sea level (msl) and extends west from the river to
Route 44. Topography from this point slopes up toward the west from an elevation
between 420 feet msl and 430 feet msl in the area of Route 44 to an elevation of
approximately 495 feet msl in the vicinity of the landfill office and maintenance garage. j
DRAFT 12 April 29, 1993
A ridge west of the landfill runs southwest to northeast across the western portion of
the RRDD#1 property. Elevations in the vicinity of the ridge range from approximately
510 feet msl on the western side of the landfill to in excess of 800 feet msl along the
crest of the ridge.
Elevations on the landfill range from approximately 500 feet msl on the north
and east portions of the landfill to approximately 590 feet msl at the time of the
topographic survey performed in 1990. Elevations on the southern and western
perimeters of the landfill vary from approximately 550 feet msl to 510 feet msl,
respectively.
A borrow area exists to the southeast and south of the landfill. Excavation has
occurred in this area to provide landfill cover material. Sand and gravel excavation has
occurred, and is an ongoing activity, north of the landfill in the vicinity of the
Barkhamsted Town Garage.
The site is within the Farmington River drainage basin. The Unnamed Brook
originates southwest of the landfill and flows north along the western boundary of the
landfill until it flows off the RRDD#1 property in the vicinity of MW-106 (Figure 2).
After flowing off the property, the Unnamed Brook changes course to the northeast, and
then to the east as it flows through a culvert under U.S. Route 44. The Unnamed
Brook changes from a single channel to a braided pattern between 200 and 250 feet east
of monitoring well nest MW-111.
Drainage from the RRDD#1 property is derived from two sources, precipitation
and seeps occurring at \arious locations around the landfill. Figure 3 illustrates
precipitation drainage path\*a\s. A description of the surface water drainage pattern
follows.
DRAFT 13 April 29, 1993
Precipitation Drainage
1. Sedimentation basin #1 lies along the southern edge of the landfill
(Figure 3). Surface water runoff from the southern face of the landfill,
the western portions of the borrow area, and a leaf composting and wood
pile ares flows into sedimentation basin #1. Outflow from this basin is
to the west into the Unnamed Brook.
2. Sedimentation basin #2 is situated to the east of the access road which
runs along the east side of the landfill . Surface water runoff from the
southeastern face of the landfill and the eastern portions of the borrow
and wood pile areas flow into this basin. Outflow is to a small marshy
area which flows to a storm water catch basin along the eastern shoulder
of the main access road.
3. A drainage swale exists across the eastern side of the landfill. This swale
diverts runoff to a storm water catch basin along the western edge of the
main access road.
4. Runoff from the west and northwest faces of the landfill drains into the
Unnamed Brook.
5. Runoff from the north to northeast face of the landfill drains into the site
storm water drain system.
6. The RRDD #1 storm drain system consists of four components based
upon the number of discharge points from the site. Figure 3 illustrates
the RRDD *1 site storm drain system. The storm drain system consists
of gutters and swales which discharge to approximately 25 storm water
catch basins. Catch basins are located along the main access road along
DRAFT 14 April 29. 1993
the eastern edge of the landfill, along the access road from Route 44 to
the recycling area, in the recycling and maintenance building area, and
on the Barkhamsted Town Garage property.
There are three discharges to the Unnamed Brook. The first discharge point to
the Unnamed Brook is a 42-inch diameter pipe north of well nest MW-5. This
discharge includes runoff from the landfill upper access road. A second discharge is
to the same location, from a culvert west of the recycling area which collects runoff
from the vicinity of the landfill office and recycling area. The third discharge to the
Unnamed Brook is a 24-inch pipe located approximately 170 feet north west of the
Barkhamsted Town Garage. This discharge includes run-off from the lower access road
and the Town Garage property.
A separate discharge occurs through a 20-inch pipe which collects storm water
from a depression just south of the intersection of the RRDD #1 main access road and
Route 44. This pipe discharges to the undeveloped property on the east side of Route
44.
Seep Drainage
A component of the leachate sampling program required that the Barkhamsted
Site be surveyed during a wet period to identify all potential seeps at the site. This
survey was conducted on October 15 and 16, 1992, following a light rain event.
Although the seeps identified during the LFI were revisited during the Phase 1A seep
survey, their designations have been changed based on this more recent survey. Twelve
leachate seeps uere identified during the survey as shown in Figure 3. Estimated flow
and discharge points for each seep is presented below:
DRAFT 15 April 29, 1993
Seep Estimated Flow Discharge Point
Seep #1* 1-3 gpm Unnamed Brook
Seep #2 <.5 gpm Unnamed Brook
Seep #3 <.5 gpm Unnamed Brook
Seep #4 <.l gpm Unnamed Brook
Seep #5 <•! gpm Unnamed Brook
Seep #6 <.5 gpm Unnamed Brook
Seep #7 1-2 gpm Unnamed Brook
Seep #8 <.l gpm Unnamed Brook
Seep #9 <.l gpm Catchment Basin #15
Seep #10 <.l gpm Vicinity of MW-110 nest
Seep #11 1-3 gpm Unnamed Brook via storm sewer
Seep #12 0.5 - 1 gpm West of Town Garage
* The source of Seep #1 is Seep #11 via the storm sewer system.
2.06 Surface Soils
Soil types for the site were evaluated by reviewing the Lichtfield County Soil
Survey (USDA, 1970). According to the soil survey, the majority of the soils in the
landfill area are classified as Charlton very stony, fine, sandy loam with slopes from 3%
to 15% (CrC). It should be recognized that surface soils in the landfill area have been
subjected to disturbance since preparation of the soil survey in 1970. Soils surrounding
the landfill include the Charlton (CrC, CrD, ChB), Hollis (HrC, HxE), Hinckley (HkC).
Sutton (SxA, and Leicester, Ridgebury and Whitman (Lg) series (USDA, 1970). The
site soils map for the landfill area is presented as Figure 4 of the Wetland Delineation
Report, included as Appendix A.
DRAFT 16 April 29, 1993
2.07 Surface Water
The Unnamed Brook, originating southwest of the landfill, is designated as a
Class B/A stream (CTDEP, 1987). This designation indicates that the stream may not
be meeting Class A water quality criteria or one or more Class A uses such as a
potential drinking water supply, fish and wildlife habitat, agricultural and industrial
supply, and recreational use. The State goal for this stream is Class A.
The Unnamed Brook discharges to the West Branch of the Farmington River
which is located approximately 0.25 miles east of the landfill. The river is designated
as a Class Be surface water which indicates that although the river is not a potable
water supply, it is presumed to meet water quality criteria for the support of cold water
fisheries (CTDEP, 1987).
2.08 Ground Water
Ground water at the landfill is classified as GB/GA by the CTDEP (CTDEP,
1987). The GB/GA classification includes the area north of the Barkhamsted-New
Hartford town line between the Unnamed Brook west of the landfill and Route 44. The
GB/GA designation indicates that the ground water may not be suitable for direct
human consumption without treatment due to waste discharges, spills, or chemical leaks
or land use impacts. The State's immediate goal is to maintain the ground water at
Class B conditions, while the long term goal is to return the ground water to drinking
water quality.
Ground water in the area surrounding the landfill is classified as GA (CTDEP,
1987). This designation applies to ground water within the area of influence of private
and potential public water supply wells. Class GA ground water is presumed suitable
DRAFT 17 April 29, 1993
for direct human consumption without treatment. The State's goal is to maintain the
drinking water quality class GA standard.
A discussion of ground water users in the vicinity of the landfill is presented in
Section 4.05 of this report.
DRAFT 18 April 29, 1993
SECTION 3 - SOILS AND SOURCES OF CONTAMINATION
3.01 General
The objectives of the Soils and Sources of Contamination portion of the RI/FS
is to evaluate the nature and extent of contaminant sources associated with the
Barkhamsted Site, characterize the site, and to evaluate the contaminant fate and
transport. In addition, data were obtained for the USEPA for conducting a risk
assessment.
The Barkhamsted Site Phase 1A Site Characterization (Phase 1A) was performed
using a phased approach. Initially, investigations were performed in areas that the
Limited Field Investigation (LFI) Summary Report (O'Brien & Gere; September, 1992)
identified as potential source areas. These investigations included geophysical surveys
to further define the horizontal extent of anomalies identified during the LFI. Results
of the LFI investigations and Phase 1A geophysical surveys were used to conduct a soil
gas survey. Finally, a soil boring program was completed based upon the results of the
LFI, Phase 1A geophysical surveys, and Phase 1A soil gas survey. A summary of the
soils and sources of contamination investigations are shown in Figure 4.
3.02 Phase 1A Geophysical Surveys
Geophysical survey techniques consisting of magnetometer, electromagnetic
(EM) terrain conductivity, and electrical resistivity were utilized on and around the
landfill site as shown in Figure 4. The surveys were used to further define LFI
geophysical anomalies, obtain information on buried waste, identify potential
contaminant plumes, and evaluate the site geologic and hydrogeologic conditions.
DRAFT 19 April 29. 1993
Two grid areas were established south of the landfill disposal area (Figure 4) to
be utilized for the EM and magnetometer surveys. One grid area is located in Area F,
in the vicinity of GPR anomalies identified by Fuss & O'Neill (Fuss & O'Neill, 1991b).
The second grid area is located in Areas G and H in the vicinity of the metals grindings
waste cell. The grid node spacings at each area varied based on area! extent, but were
established at 50-ft intervals over most of the areas. Where the data indicated the
presence of isolated anomalies, the grid spacings were reduced to 10-ft intervals to
obtain more detailed data in the anomalous areas.
Field Modifications
• Landfill operations resulted in the scrap metal pile having been relocated
to Area F. Due to large amounts of scrap metal at the surface, EM-31
in-phase surveys were not attempted in the southern half of Area F south
of and including grid line N-60 through N-64 (Figure 5).
3.02.1 Magnetometer Surveys
Magnetometer surveys were utilized to evaluate the bulk intensity of the
earth's magnetic field and secondary magnetic fields emanating from buried
ferrous materials.
Methods
The magnetometer surveys were performed using an EG&G Geometries
Model G-816/826 Portable Proton Magnetometer in accordance with the
operational instructions in the equipment manual. Magnetometer surveys were
performed on October 12 and 13, 1992 in Areas G, Area H and Area F,
DRAFT 20 April 29, 1993
respectively. Based upon the results of the initial survey, an expanded
magnetometer survey was completed on October 15, 1992 in Areas G, H. and F.
During implementation of the magnetometer survey, base station readings
were recorded at the LFI base station located to the east of the landfill check-in
station on the grass island as illustrated on Figure 4. The purpose of the base
station was to periodically monitor changes in magnetic readings throughout the
day due to diurnal changes in the earth's magnetic field. Generally, measure
ments were taken at the base station on an hourly basis during the operation of
the magnetometer. Magnetometer base station readings are included in Table 1.
Magnetometer readings were recorded at each grid node by orienting the
magnetometer sensor in a northerly direction, and obtaining three readings.
These readings were subsequently averaged and are presented in Table 1. The
averaged readings were plotted on a survey grid map and are illustrated on
Figure 6. The discussion of the magnetometer survey results is presented with
the EM quadrature survey results in Section 3.02.2 below.
3.02.2 Electromagnetic Surveys
Electromagnetic surveys were conducted using the EM-31 in two modes
of operation, an in-phase mode and a quadrature phase mode. EM terrain
conductivity surveys were utilized to evaluate changes in natural ground
conductivities and/or resistivities when operated in the quadrature phase mode.
In-phase mode EM terrain conductivity surveys were utilized to detect buried
metallic objects.
DRAFT 21 April 29, 1993
Methods
Terrain conductivity surveys were performed using a Geonics* EM-31
terrain conductivity meter. Prior to initiating the EM-31 quadrature mode
surveys each day, a system check of the unit was completed at the base station
in accordance with the standard operating procedures specified in the equipment
manual. The base station location is illustrated on Figure 4. The EM-31 terrain
conductivity survey was performed in Areas G, H, and Area F on October 12,
1992.
Quadrature phase terrain conductivity data values were measured within
the two surveyed grid areas at each accessible grid node. Data were recorded
in mmhos/meter and are presented in Table 2. The survey data were collected
by first aligning the EM-31 receiver along a north-south axis, then along an east-
west axis. The two values were recorded at each accessible grid node to
evaluate any lateral changes in terrain conductivity. Figures 7 and 8 illustrate
the EM terrain conductivity data collected in north-south and east-west
orientations, respectively.
To evaluate the presence of buried metallic waste materials, the EM-31
receiver was operated in the in-phase mode at each accessible grid 'node within
each of the two grid areas. The EM in-phase survey was performed on October
13, 1992. While conducting the survey, needle deflections on the EM-31
receiver were noted in a field book. These deflections indicate possible
subsurface metallic materials. Areas where the needle deflections indicated the
likely presence of buried metallic waste materials are illustrated on Figure 5.
DRAFT 22 April 29, 1993
Results
The results of the EM-31 quadrature mode, EM-31 in-phase mode, and
magnetometer surveys are discussed together in this section. This approach is
utilized to evaluate observed anomalies relative to either background values or
average values for the particular areas of interest. The anomalous areas
delineated using these techniques are likely attributed to buried metallic wastes
or highly conductive materials. Figure 6 illustrates the magnetometer survey
contoured results. Lateral changes in terrain conductivity values across the site
relate to the thickness of the fill. Figures 7 and 8 illustrate terrain conductivity
contours for a north to south and east to west orientation, respectively. Figure
5 shows EM-in-phase anomalous results. A discussion of the results is as
follows:
• Lateral changes in terrain conductivity between grid nodes N-l and N-32
(Figures 7 and 8) correlate with changes in fill thickness in this vicinity.
• Elevated terrain conductivity values coincident with dipolar magnetom
eter data in the vicinity of grid nodes N-l6 and N-l8 (Figure 6) likely
indicates the presence of subsurface ferrous material. This result
supports the LFI geophysical survey results and the suspected location
of the metals grinding waste cell.
• Terrain conductivity and magnetometer values approached background
values south of grid line N-23 to N-33 (Figures 6, 7 and 8) off of the
landfill disposal area indicating fill does not extend south of this line.
• EM in-phase results indicated potential buried metallic waste in the
vicinity of grid nodes N-30, N-31, N-32, and N-36 (Figure 5). This
DRAFT 23 April 29, 1993
finding resulted in the installation of soil gas points SG-30, SG-32, SG
35, and SG-36 as discussed in Section 3.03.
• EM terrain conductivity and magnetometer surveys conducted in Area F
generally indicate data values slightly above background indicating that
fill does not exist in this area.
• Anomalous EM terrain conductivity values of less than zero were
detected in both the north-south and east-west orientations in the vicinity
of grid node N-36. A dipole magnetic response was also detected with
the magnetometer in the vicinity of grid nodes N-56, N-57, and N-58.
This is likely indicative of buried ferrous materials which correlates well
with EM in-phase data that indicates strong responses to subsurface
ferrous materials in the vicinity of grid nodes N-56 and N-58. This
finding resulted in the installation of soil gas points SG-20, SG-21, and
SG-22 as discussed in Section 3.03.
• Although EM terrain conductivity surveys were performed in the
southern portion of Area F, data appear to be influenced by the surface
scrap and are most likely not indicative of subsurface conditions.
3.023 Resistivity Surveys
Fourteen electrical resistivity surveys were used to evaluate vertical
heterogeneities in the subsurface materials, the depth to the water table,
overburden thicknesses, and depth to bedrock.
DRAFT 24 April 29, 1993
Methods
The resistivity surveys were conducted with the Bison Model 2390 Signal
Enhancement Earth Resistivity System and Schlumberger electrode configura
tion. The Schlumberger configuration requires the spacing of the two inner
electrodes to remain constant. The spacing of the two outer electrodes varies to
provide greater depth sensitivity. The locations of the resistivity soundings are
illustrated on Figure 9.
The current electrode spacings (AB) for the individual resistivity
soundings varied in length from 200 to 400 feet. Potential electrode spacings
(MM) were increased when the potential voltage difference dropped below 1.0
millivolts. The collected resistivity data were reduced using the computer
program "A Computer Program for the Automatic Interpretation of
Schlumberger Sounding Curves Over Horizontally Stratified Media", 1973, by
A.A.R. Zhody; NTIS PB-232-703, along with RESIX, a computer software
modelling package for resistivity data by Interpex Limited. The computer
processed data were used to provide estimates of the depth to ground water and
bedrock. The interpreted data is summarized on Table 3. Computer processed
resistivity plots and data sheets are included in Appendix B.
Results
Bedrock elevations were estimated across the site from the resistivity data
and compared to depths obtained from monitoring well logs. A bedrock
elevation map was prepared from data obtained from the bedrock borings. The
estimated depths to bedrock were then superimposed on the bedrock elevation
map to determine how well the estimated bedrock depths obtained from the
DRAFT 25 April 29, 1993
resistivity surveys correlated with the bedrock depths obtained from the bedrock
borings. The results are as follows:
• Five resistivity surveys (R-2, 4, 6, 7, and 12) provided acceptable depth
to bedrock/overburden thickness data. These surveys resulted in an
average of 15 percent difference between the bedrock elevations assessed
from bedrock monitoring wells and the estimated bedrock surface
ascertained through the resistivity surveys. Bedrock elevation data
obtained from these five surveys fill in data gaps where no wells or
borings exist. The level of confidence in the accuracy of the data is high
due to good correlation of the data.
Resistivity surveys R-l, 3, 5, 8, 9, 10, 11, 13, and 14 (Figure 9) did not
produce highly correctable data. The average percent difference
between the conceptualized bedrock surface and the estimated bedrock
surface ascertained through the resistivity surveys is approximately 63
percent. The inability to approximate the bedrock surface at the above
survey points can be attributed to the following:
• R-l was completed in an area with a substantial change in
elevation which may have obscured interpretation of the bedrock
surface.
• R-3 was completed over a subsequently discovered large diameter
steel culvert which prevented adequate electrical penetration to
the subsurface.
DRAFT 26 April 29, 1993
R-5 and R-13 were completed in an areas where highly conduc
tive leachate may have prevented adequate electrical penetration
to the subsurface.
• R-8, R-10, R-l 1, and R-14 were completed in areas with resistive,
hard packed, dry sands and gravels which prevented adequate
electrical coupling and electrical penetration to the subsurface.
• R-9 was completed in an area of loose, highly organic soils which
prevented adequate electrode coupling and electrical penetration
to the subsurface.
• Bedrock elevation information obtained from the bedrock wells around
the site indicate bedrock dipping to the north-northeast (Figure 10). The
bedrock elevations estimated from resistivity surveys B-2, 4, 6, 7 and 12
generally fall within the bedrock contours created from well information
as illustrated on Figure 10.
• Water table elevations were estimated from the resistivity surveys. The
water table elevations estimated from the surveys were compared to the
water table elevations from overburden wells as presented in Table 4.
The results are as follows:
• Water table depths estimated from soundings R-l, R-5, and R-l2
correlate well with water table elevations at those locations. The
average difference between actual water table elevations and the
estimated water table elevations determined from resistivity is
approximately 9 percent.
DRAFT 27 April 29, 1993
Water table depths estimated from soundings R-2, 3, 4, 6, 7, 8, 9,
10, 11, 13, and 14 showed large deviations from the water table
elevations measured on January 26, 1993. An average difference
of 198 percent was calculated for these soundings.
• Difficulties were encountered in trying to identify the limits of fill
and fill thicknesses from the resistivity data. Changes in the
computer modelled resistivity data appear to represent saturated
overburden materials and overburden/bedrock interfaces.
Discemable changes in resistivity due to fill materials were not
evident in the models.
3.03 Soil Gas Sampling
3.03.1 Introduction
The following summarizes the soil gas survey performed at the
Barkhamsted Landfill Superfund Site between the dates of November 3, 1992
and December 3, 1992.
Two portable gas chromatographs (GCs) were used to analyze 165 soil
gas samples. The objective of the soil gas sampling was to semi-quantitatively
evaluate the concentration, chemical composition, and horizontal extent of
volatile organic compounds (VOCs) in the subsurface soil, to a depth of 3 feet
below grade, at eleven areas on-site. The areas investigated included: A, B, C,
E, F, G, J. K. the Recycling Area, previously cleared area #1, and previously
cleared area =2, as shown in Figure 11.
DRAFT 28 April 29, 1993
3.03.2 Methods
Sample Locations
Fifty-five sample locations were initially staked based on the
results of the LFI soil gas and geophysical surveys. Consistent with the
procedures outlined in the Field Sampling Plan (FSP) Appendix FSP-B,
additional locations were added based on initial sample results.
Presented in the following table are the number of initial samples and the
total number of samples collected for each area of study. In most
instances, additional soil gas samples were installed outside of the
original area of investigation. Soil gas sampling locations are illustrated
in area detail maps on Figures 11A through 11F.
Area of Investigation Initial Number of Samples Total Number of Samples
Area A 4 10
Area B 2 15
Area C 6 30
Area E 5 16
Area F 7 19
Area G 12 32
Area J 4 13
Area K 5 6
Previously Cleared Area 1 4 18
Previously Cleared area 2 4 4
Recycling Area 2 2
Soil Gas Sample Collection
Soil gas samples were collected using dedicated aluminum shield
points attached to a length of teflon tubing. The teflon tubing/shield
DRAFT 29 April 29, 1993
point assembly was driven to depth of 3 feet using hardened steel probes
(7/8" OD) and an electric impact hammer. Prior to collection of a
sample, the hardened steel probe was retracted 3 to 6 inches to expose
the vapor intake slots of the shield point. One hundred milliliters (ml)
of soil gas was then purged from the system to minimize ambient air
contributions to sample results. Soil gas samples for GC analysis were
collected by attaching a 50 ml glass syringe, equipped with a teflon
stopcock, to the teflon tubing/shield point assembly and drawing back the
plunger. The syringe stopcock was then closed to secure the sample and
the syringe was transported to the office trailer for analysis. A vacuum
gauge was placed in-line during collection of soil gas samples to
qualitatively evaluate soil porosity in each area of collection. A 100 ul
gas-tight syringe was used to extract an aliquot of sample from the 50 ml
syringe for injection into the Photovac GC and 10 ml of sample was
drawn into the Sentex GC directly from the 50 ml syringe.
Field Modifications
Analytical instruments - Due to operating problems incurred with
the Hewlett-Packard 5890 Series II GC, the Photovac and Sentex
GCs were substituted. The substitution was communicated to
EPA prior to initiating the soil gas survey. Analysis protocols
established for the Hewlett-Packard were unchanged.
Chemical concentration action level - As stated in the FSP, "If a
VOC anomaly (i.e. > background total VOCs with portable GC)
DRAFT 30 April 29, 1993
is detected, then the soil gas survey will be expanded on a grid
with a 50-foot spacing". The action level of greater than
background was modified. Instead, the preliminary results for
each area of study were discussed with the EPA Project Manager
to define additional soil gas locations to be used to accomplish
the survey objectives. This approach was adopted in an attempt
to delineate each area of study effectively while minimizing the
number of samples required to do so. It should be noted that
preliminary results were obtained by totalling the chromatogram's
peak area and quantifying using the benzene response factor,
only. Since the final results were quantified on an individual
peak basis, results may vary slightly from preliminary results.
The difference is a result of the different response factors for the
calibrant compounds used for the survey.
GC initial calibration - Initially GC calibration was performed by
using one standard concentration and adjusting the instrument
gain to mimic varying concentrations. Subsequently, calibrations
were performed in accordance with the protocols by running three
unique concentration standards at a fixed instrument gain. A
comparison of the two methods indicated both provided similar
results.
Documentation of the standards preparation log - Metcalf and
Eddy, USEPA oversight personnel requested that the O'Brien and
Gere GC operator expand documentation related to the
DRAFT 31 April 29, 1993
preparation of standards. Therefore, in addition to documentation
denoted on the chromatograph printout, the concentration of each
calibrant was written on the standards chromatograph report
sheets.
Multi-component standards - Metcalf and Eddy, the US EPA
oversight personnel, requested that standards be injected
individually, rather than as part of a multi-component standard
mix, to minimize potential errors associated with misidentification
of constituents. Therefore, individual standards were prepared for
verification of chemical retention time.
Vacuum gauge for sample collection - Initial vacuum gauge
readings were inconclusive due to the poor cohesiveness of
surface soils. These observation resulted in the discontinued use
of vacuum gauges. The use of the vacuum gauge was
reimplemented in accordance with the protocols, upon a request
from Metcalf and Eddy oversight personnel.
GC Calibration
A Photovac 10S70 portable GC equipped with a CPSIL-5
capillary column, isothermal column oven and 10.6 eV photoionization
detector, and a Sentex Scentograph portable GC equipped with a SP
2100 packed column, isothermal column oven, and an electron capture
detector, were used to complete the analysis of the soil gas samples. The
GCs were calibrated to the compounds identified during the Fuss and
DRAFT 32 April 29, 1993
O'Neill (1990) investigation (benzene, toluene, xylene, vinyl chloride,
trans-1.2-dichloroethene, trichloroethene, methyl ethyl ketone, and methyl
isobutyl ketone). The GC calibration consisted of both initial calibration
and continuing calibration.
Initial Calibration: Prior to initiation of field activities, the
Photovac GC was calibrated to the aromatic and ketone compounds and
the Sentex to the chlorinated compounds. The Photovac GC was
calibrated to benzene, toluene, xylene, methyl ethyl ketone, and methyl
isobutyl ketone, and the Sentex GC was calibrated to vinyl chloride,
trans-l,2-dichloroethene, and trichloroethene. A four point calibration
was completed for each of the above mentioned compounds, including
a zero level standard or method blank and three concentration levels.
Continuing Calibration: During the field investigation, the
Photovac was calibrated to a mid-level concentration standard of
benzene, toluene and xylene and the Sentex to a mid-level concentration
standard of vinyl chloride, trans-1,2-dichloroethene, and trichloroethene.
Continuing calibration was performed at the start of each day, and after
every ten sample analyses.
Sample Quantification
A least squares regression was performed to develop an equation
for each calibrant which relates peak area to sample concentration.
Results of sample analyses were quantified by comparison to the
calibration equations. Sample peaks which were consistent with a
DRAFT 33 April 29, 1993
calibrant peak, on the basis of retention time, were quantified using the
corresponding calibration equation. Sample peaks inconsistent with
calibrant standards were grouped and labelled Other VOCs. Other VOCs
were quantified using an average of the calibration equations.
Quality Control
The following quality control measures were taken during the
investigation: 1) GC blanks, 2) equipment decontamination, 3) sample
collection blanks, 4) syringe blanks, 5) sampling variability evaluation,
and 6) accurate record keeping.
1) GC Blanks: GC blanks were run at the beginning of every day.
A GC blank consists of an analytical run without introduction of
sample.
2) Equipment Decontamination: The hardened steel probes used to
install the aluminum shield points were decontaminated between
each sample using a soapy water wash followed by a water rinse.
3) Sample Collection Blanks: A sample collection blank was
collected once per day. The sample collection blank was obtained
by passing ambient air through the sample collection apparatus
and into a 50 ml glass syringe.
4) Svringe Blanks: A syringe blank was performed after each
calibrant set and after each environmental sample which exhibited
detectable concentrations of VOCs. Syringe blanks were obtained
from the 50 ml collection syringe using a 100 /xl gas tight
DRAFT 34 April 29, 1993
syringe. If VOCs were observed in the syringe blank, additional
blanks were run until blank response returned to background.
5) Analytical Variability: In order to assess the variability associat
ed with analysis of environmental samples, three sets of duplicate
samples were analyzed. Duplicate samples were obtained by
collecting two samples from one sampling point. The relative
percent differences (RPD) ranged from 0.59% to 8.76%, based on
total VOC concentrations. This result is within QA/QC criteria.
6) Record Keeping: Chromatograms were taped into analytical note
books. Information detailed on each chromatogram included:
sample number, site name, date/time of collection, date/time of
analysis, column and detector type, injection volume, back-flush
time, carrier gas flow rate, and instrument gain setting. In
addition to the information printed on the chromatographs,
documentation of standard preparation was logged, and field notes
(i.e. ground water was encountered at 1 foot) were documented
on the data sheets.
7) Instrument Performance: A four point calibration was completed
for each calibrant compound to establish a retention time window
and calibration equation (response factor) for each. The GCs
were also calibrated to the calibrant compounds (at the start of
each day) to evaluate variability in instrument performance
throughout the investigation. Results of the initial and continuing
calibration are summarized and presented in the raw data. R
DRAFT 35 April 29, 1993
squared values ranging from 0.992 to 0.999 were obtained for the
initial calibration.
3.03.3 Results
The objective of the soil gas survey was to delineate the areal extent of
VOCs in the vadose zone and to aid in the selection of soil boring locations.
These objectives were accomplished for each of the eleven areas of
investigation. Figures FSP-11 shows the areas of investigation and provides an
index for Figures 11A through 1 IF which illustrate the extent and results of soil
gas surveys within each area of investigation. A discussion of the results
obtained for each area is presented in the following paragraphs.
Area A - Approximately ten samples were utilized to delineate Area A
(Figure 11 A). The highest concentrations in this sample group were observed
at locations SG-3B and SG-3 which exhibited total VOC concentrations of 32.3
and 57.4 ppm, respectively. Sample SG-3 was situated at the southeastern
boundary of Area A, and Sample SG-3B was located 50 feet to the east. The
northern extent of VOCs was defined by sample SG-2A, situated 50 feet north
of sample SG-2. To the west, the extent of VOCs in soil gas was defined by
samples SG-2DD and SG-2DA, situated 50 feet west of samples SG-2D and
SG-2A, respectively. No additional samples were installed to delineate VOCs
in the southern direction, due to the low concentration observed in sample SG-1
and the presence of perched ground water in this area. The primary constituents
observed in Area A were toluene and xylene. The remaining calibrant
DRAFT 36 April 29, 1993
compounds, with the exception of methyl ethyl ketone, were observed at
concentrations ranging from 0.015 to 2.7 ppm.
Area B - Approximately fifteen samples were collected to delineate Area
B (Figure 11 A). The highest concentrations of VOCs were detected in the
southern portion of Area B. Samples SG-5, SG-5C, SG-5DD, and SG-9
exhibited total VOC concentrations of 10.5, 30.6, 26.0, and 44.2 ppm,
respectively. The primary constituents observed in this area were benzene,
toluene and xylene. The chromatographic pattern observed from samples
collected from Area B was consistent with that of a petroleum hydrocarbon
residue. Trace concentrations of the remaining calibrant compounds, excluding
MEK, were also detected. The extent of VOCs to the south was the toe of the
landfill, SG-3A, SG-6 and SG-9AW to the north, and SG-9AB, SG-9B, and SG
9C to the east. The western extent of VOCs was defined by Area A.
Area C - Approximately thirty samples were utilized to delineate
subsurface VOCs in Area C (Figure 11 A). Each of the eight calibrant
compounds were detected in this area. Samples LISG-106, LISG-106D, LISG
106AB, and SG-11Z, situated in the northern portion of Area C, exhibited the
highest total VOC concentrations in this area, at 55.6, 49.1, 27.7, and 10.8 ppm,
respectively. The remaining 25 samples exhibited total VOC concentrations
ranging from non-detect (<0.010) to 3.3 ppm. The areal extent of VOCs was
established by samples LISG-106AADA and LISG-106AAA to the north, LISG
106ABA. LISG-106ABB, LISG-106B, LISG-106Y, and SG-11B to the east,
LISG-106AADD, SG-8A, SG-8D, SG-8Y, and SG-7 to the west, and Area B to
the south.
DRAFT 37 April 29, 1993
Area E - Approximately 19 samples were collected to delineate the extent
of subsurface VOCs in Area E (Figure 11B). Samples LISG-62DA, LISG-62C,
SG-16Z, and LISG-62-2, situated in the western portion of Area E, exhibited
total VOC concentrations of 11.5, 19.7, 15.4, and 3.8 ppm, respectively. The
twelve remaining samples exhibited total VOC concentrations ranging from non-
detect to 2.97 ppm. A mix of chlorinated and aromatic hydrocarbons were
observed in Area E. The chromatographic fingerprint observed in samples with
relatively high total VOC concentrations was consistent with that of a petroleum
hydrocarbon residue. Subsurface VOCs were found to extend approximately
100 feet north of SG-16, the northern most initial sample, as defined by sample
LISG-62DAA. The western extent of VOCs was defined by samples LISG
62DAD, LISG-62DD, and SG-13 and the eastern extent by samples LISG-62A,
LISG-62B, and SG-17. No additional samples were collected to the south of the
initial sample points.
Area F - Approximately nineteen samples were utilized to delineate
Area F (Figure 11C). Total VOC concentrations observed in the these samples
ranged from non-detectable (<0.025 ppm) to 4.79 ppm. Compounds detected
in this area included vinyl chloride, benzene, MEK. (one sample), MIBK. (one
sample), toluene and xylene (one sample). The highest total VOC concentration
was observed in sample SG-20D, located in the western portion of Area F.
Total VOC concentrations dropped off to near background within 50 feet in each
direction. The northern extent of subsurface VOCs was defined by samples SG
20DAA and SG-23A, the western extent by samples SG-20DAD, SG-20DD and
DRAFT 38 April 29, 1993
SG-20DC, and the eastern extent by samples SG-23B and SG-24. No additional
samples were collected south of the initial sample locations.
Area G - Thirty-two samples were collected to delineate subsurface
VOCs in Area G (Figure 11D). Total VOC concentrations in the 32 samples
ranged from non-detect (O.025) to 20.59 ppm. The highest total VOC
concentrations were observed in the northwestern portion of Area G, in samples
SC-25C, SG-27, and SG-27Z. Benzene, toluene and xylene were the major
constituents detected in Area G, while the remaining calibrant compounds were
detected at trace concentrations. The chromatographic pattern observed for
samples from Area G was consistent with that expected for a petroleum
hydrocarbon residue. Sampling was advanced approximately 150 feet to the
south, 100 feet to the west, and 100 feet to the east of initial sample locations,
before near background VOC concentrations were observed. No additional
sampling was necessary in the northern direction.
Area J - Approximately thirteen samples were collected for GC analysis
from Area J, the suspected hazardous waste disposal area (Figure 11B). Total
VOC concentrations observed in samples collected from Area J ranged from
non-detect (<0.025 ppm) to 86.63 ppm. Compounds detected in this area
included vinyl chloride, MEK (one sample), benzene, TCE, MIBK, toluene and
xylene. The highest soil gas concentrations were observed at locations SG
37DC, SG-37DCC, and SG-37D, situated along the eastern boundary of the
landfill.
DRAFT 39 April 29, 1993
Area H - Soil gas samples SG-28CCB, SG-32. and SB-35 were installed
in the vicinity of Area H (Figure 1 ID). Results of these soil gas points did not
indicate the need to expand the soil gas survey into Area H.
Area K - Approximately six samples were collected for GC analysis
from Area K (Figure 11B). The total VOC concentrations observed in Area K
samples ranged from non-detect (<0.025 ppm) to 0.61 ppm. The calibrant
compounds observed in samples collected from Area K included vinyl chloride,
DCE, benzene, toluene, and xylene. The concentrations observed in samples
collected from this area are not consistent with that expected for a contaminant
source area.
Recycling Area - Two samples were collected from the Recycling Area
(Figure HE). Samples SG-44 and SG-43, exhibited total VOC concentrations
of non-detect (<0.025 ppm) and 0.31 ppm, respectively. Sample SG-43
exhibited trace concentrations of vinyl chloride, benzene, and toluene. No
additional samples were collected to further define the area.
Previously Cleared Area #7 - A total of 22 samples were collected to
delineate subsurface VOCs in Previously Cleared Area #1 (Figure 11C). Total
VOC concentrations ranged from non-detectable (O.025 ppm) to 13.83 ppm.
The highest total VOC concentrations were observed in samples SG-49CC. SG
49CCY, SG-49CD, and SG-49CDZ, situated in the southwestern portion of the
area. VOCs inconsistent with calibrant compounds made up the bulk of the total
VOC concentrations observed in samples collected from this area. Calibrant
compounds detected included vinyl chloride, toluene and xylene. The
DRAFT 40 April 29, 1993
contaminants extended approximately 150 feet to the south, 100 feet to the west,
and 50 feet to the east of the initial points (SG-49, 50, 51, and 52).
Previously Cleared Area #2 - Four samples were collected to delineate
subsurface VOCs in Previously Cleared Area #2 (Figure 11F). Total VOC
concentrations observed in the four samples ranged from non-detect (<0.025
ppm) to 0.50 ppm. Calibrant compounds detected include vinyl chloride, DCE,
and toluene. Based on the low total VOC concentrations observed in the four
initial samples, no additional samples were collected from this area.
In summary, the objectives of the soil gas survey were to delineate the
area! extent of subsurface VOCs and aid in the selection of soil boring locations.
These objectives were met by tracking the extent of VOCs in each area until
near, background total VOC concentrations were obtained in each direction, or
until an area was delineated to the mutual satisfaction of O'Brien and Gere and
USEPA. In addition, soil gas data were reduced in the field to provide site
personnel with the preliminary data necessary to select locations for additional
soil borings. Total VOCs typically associated with potential source areas are
greater than 1 ppm. Seventy percent of the Phase 1A soil gas points were less
than 1 ppm, which indicates that the potential sources areas outside the landfill
disposal area are not VOC source areas.
3.04 Landfill Gas Sampling
The following summarizes the landfill gas survey performed during November
and December 1992. The objective of the survey was to qualitatively evaluate the
presence of landfill gas at the site (primarily methane) and the potential for off-site
DRAFT 41 April 29, 1993
migration of landfill gas. Landfill gas sampling locations and results are illustrated on
Figure 12.
3.04.1 Methods
Sample Locations
A total of twelve sample locations were initially selected for
sampling and analysis. The landfill gas sampling was conducted around
the periphery of the landfill to the north, east, and south of the main fill
area to evaluate the potential migration of landfill gas. Landfill gas
samples were not collected along the west side of the main fill area
based on the assumption that the Unnamed Brook acts as a barrier for the
migration of landfill gas. The landfill gas samples collected were
analyzed in the field using a Gas-pointer model H combustible gas
indicator.
The landfill gas samples were collected at 200-foot intervals
around the main fill area at the locations indicated on Figure 12. If
methane was detected at concentrations greater than 2% at any given
sampling location, additional landfill gas samples were collected to better
delineate the extent of elevated landfill gas readings. Additional samples
were situated at locations 100 feet on either side of the point at which
methane was detected at greater than 2 percent. Additional samples were
collected near samples LG-2 and LG-3, the only initial samples
exhibiting methane gas readings of greater than 2 percent.
DRAFT 42 April 29, 1993
Sample Collection
Landfill gas samples were collected using dedicated aluminum
shield points attached to a length of teflon tubing. The teflon tub
ing/shield point assembly was driven to depth of 3 feet using hardened
steel probes (7/8" OD) and an electric impact hammer. Prior to
collection of a sample, the hardened steel probe was retracted 3 to 6
inches to expose the vapor intake slots of the shield point. A sample was
collected by connecting the Gas-pointer combustible gas analyzer directly
to the teflon tube.
Sample Analysis
The landfill gas samples were analyzed using the Gas-pointer
combustible gas analyzer. Initially each sample was analyzed using the
0 to 4% combustible gas scale. If 'the instrument reading stabilized
within this range (0 to 4%) the result was documented. If the meter
showed greater than 4% gas, the instrument was switched to the 0 to
100% scale and the percent combustible gas was documented.
Instrument Calibration
The Gas-pointer calibration consisted of 1) initial calibration, and
2) continuing calibration.
Initial Calibration - Prior to analysis of landfill gas samples, a
two point calibration was performed for methane, consisting of a zero
DRAFT 43 April 29, 1993
level standard or method blank and one 15% methane concentration
standard.
Continuing Calibration - was conducted prior to each sample
being analyzed by checking the internal standard according to
manufacturer's specifications and checking the zero concentration using
ambient air.
3.04.2 Results
Results of the landfill gas sampling are summarized on Figure 12. Two
initial landfill gas samples detected methane concentrations greater than 2
percent. Samples LG-2 and LG-3 (Figure 12) exhibited methane concentrations
of 90% and 10%, respectively. These samples were situated in the northern
portion of landfill, to the west of the landfill office. Additional landfill gas
sampling points LG-2A, LG-2D, LG-3 A, LG-3B, LG-3D, LG-3DA-1 were
installed to further delineate LG-2 and LG-3. As indicated on Figure 12, landfill
gas was not detected at points LG-2A, LG-3DA, and LG-3D. The elevated
methane concentrations observed in this area are likely a result of fill which
exists in this area. The results of the landfill gas sampling indicated that landfill
gas is limited to the vicinity of fill areas.
3.05 Surface Soil Sampling
Twenty-four surface soil samples were collected at the Barkhamsted Site for use
in completing the L'SEPA Risk Assessment. The locations of surface soil samples SS-1
DRAFT 44 April 29, 1993
to SS-24 are illustrated on Figure 4. The locations of surface soil samples within each
potential source area are shown on Figures 13A through 13F.
Surface soil samples SS-20 and SS-21 were collected from the Murray/Jones
property and Yahne property, respectively. Locations of these samples were reviewed
and selected with concurrence of the USEPA oversight personnel.
3.05.1 Methods
Surface soil samples were collected using a stainless steel hand auger.
At each sampling location, the hand auger was advanced to 6 inches below the
ground surface. A stainless steel spoon was utilized to remove and discard the
thin layer of soil which was in contact with the hand auger, and the remaining
sample was placed into a pre-cleaned 4 oz laboratory sample container. This
sample was submitted for TCL volatile analysis. The hand auger was then
advanced to 12 inches, and a stainless steel spoon was used to collect soil from
throughout the 12 inch column into a stainless steel bowl. The soil sample was
homogenized in the bowl and placed into a pre-cleaned laboratory sample jar for
the remaining TCL/TAL analyses. A portion of the homogenized sample was
collected and for grain size analysis using ASTM Method D-422-63. Grain size
analysis results are included in Appendix C.
3.05.2 Field Modifications
Surface soil sample SS-23 was relocated from the southeast side of the
landfill to the north to northeast side of the landfill (Figure 13C). This was the
result of landfill operations regrading and planting grass at the original proposed
location.
DRAFT 45 April 29, 1993
3.05.3 Results
Each surface soil sample was shipped to Pace Laboratories, Inc. in
Wappingers Falls, NY utilizing approved chain-of-custody procedures and
analyzed for TCL/TAL parameters listed in Table 5. Analysis results for
volatiles, semivolatiles, pesticides/PCBs and inorganics are included in Tables
6A through 6D, respectively. The following is a discussion of the analytical
results.
Background Samples
Surface soil samples SS-1 and SS-2 were collected to assess background
conditions at the site. The locations of the soil borings are depicted on Figures 4 and
ISA. The following conclusions were reached:
• Background VOCs levels were below the method detection limit in SS-1
and SS-2.
• 1,4-dichlorobenzene at 95 ^g/kg> an<^ fluoranthene at 23 /xg/kg were
detected in background sample SS-1.
• The compounds Dieldrin, 4,4-DDE, and 4,4-DDT were detected in SS-1
at estimated concentrations of 0.97 /ig/kg, 1.9 /xg/kg, and 0-21 Mg/kg,
respectively. These concentrations are all below the quantitation limit.
PCB/pesticides were not detected in SS-2.
• Background metal concentrations reveal consistent results for both SS-1
and SS-2. The concentrations provide a range in which to compare
metal concentrations detected in surface soils at other locations at the
Barkhamsted site.
DRAFT 46 April 29, 1993
AREA A
Surface soil samples SS-8, SS-10, SS-11, SS-12, SS-13, and SS-14 were
installed adjacent to Area A soil borings as shown on Figure 13B. The following
conclusions were reached for this area:
• VOCs were not detected in Area A surface soils.
• Twenty-two semivolatile constituents were detected in Area A ranging
from 17 jig/kg naphthalene in SS-11 to 3800 ng/kg of benzo(k)
fluoranthene in SS-10.
• Pesticides detected in the Area A surface soils included aldrin, alpha-
chlordane, 4,4-DDD 4,4-DDE, endrin ketone, gamma-chlordane, endrin
aldehyde, 4,4-DDT and methoxychlor. Concentrations ranged from 0.69
jig/kg, 4,4-DDE in SS-11 to 26 /xg/kg, 4,4-DDD in SS-10.
• Area A surface soil metal concentrations are discussed as follows:
With the exception of SS-8, metal concentrations elevated above
background were detected in each Area A surface soil sample.
Elevated metal concentrations ranged from less than two times
background (barium, calcium, and vanadium) to 273 times
background (SS-13;chromium).
AREA B
Surface soil samples SS-16, SS-18 were collected adjacent to soil borings
installed within Area B as illustrated in Figure 13B. The following conclusions were
reached for Area B:
SS-16 and SS-18 VOC analytical results were all below the method
detection limit.
DRAFT 47 April 29, 1993
Nineteen semivolatile constituents were detected in Area B ranging from
21 jig/kg of 2-methylnaphthalene in SS-18 to 4800 /ig/kg of pyrene in
SS-16.
• PCB/pesticide data for Area B surface soil samples are discussed below.
PCB/pesticides detected in SS-16 included 4,4-DDT at 5.2
and 4,4-DDE at 2.3 /ig/kg.
PCB/pesticides detected in SS-18 included 4,4-DDE at 1.5
gamma-chlordane at 0.99 Mg/kg> an<^ endrin ketone at 3.5
• Elevated concentrations of metals were found in each soil sample as are
discussed as follows:
Sodium, nickel, and lead were detected above background
concentrations in SS-16. The concentrations of sodium and zinc
ranged from less then two times background (sodium) to six times
background, respectively.
Barium, potassium, sodium, nickel, and lead were detected above
background in SS-18. Concentrations ranged from less than two
times background for barium, potassium, sodium, an nickel to
seven times background for lead.
AREA C
Surface soil samples SS-17 and SS-19 were collected within Area C as shown
in Figure 13B. The following conclusions were reached for Area C:
• VOCs were not detected above the method detection limit in Area C
surface soil samples.
DRAFT 48 April 29, 1993
• Three semivolatile constituents were detected in Area C surface soil
samples ranging from 17 /xg/kg of phenanthrene in SS-17 to 61 /ig/kg of
fluoranthene in SS-19.
• Pesticides detected in Area C included 4,4-DDT, 4,4-DDE, gamma
chlordane, endrinketone, and methoxyclor. Concentrations ranged from
0.70 jtg/kg of gamma chlordane to 3.5 ng/kg of endrine ketone.
• Elevated metal concentrations were detected in each surface soil sample;
however, concentrations were less than two times the background values.
AREA D
Surface soil samples SS-7 and SS-23 were collected in Area D as shown in
Figure 13C. SS-23 was collected in the vicinity of a stressed vegetation area. Results
of these analyses are discussed as follows:
VOCs were not detected above the method detection limit in SS-7 and
SS-23.
• Four semivolatile constituents were detected in Area D surface soil
samples. Concentrations ranged from 35 /zg/kg of phenanthrene in SS-7
to 110 ng/kg of pyrene in SS-23.
• PCB/pesticides results detected 4,4-DDE at an estimated concentration
of 0.42 jig/kg in SS-23. PCB/pesticides were not detected above the
method detection limit in SS-7.
• Elevated concentrations of metals, as compared to background, were
detected in B-7.
DRAFT 49 April 29, 1993
Elevated metals were detected in SS-7 with concentrations
ranging from less than two times background for aluminum,
arsenic, chromium and iron to three times background for nickel.
Sodium and lead were elevated above background values in SS
23 but were two times below background.
AREA E
Surface soil sample SS-3 was collected adjacent to soil boring B-3 as shown in
Figure 13C. The results of the sample are discussed below:
• The volatile compound 2-butanone was detected in SS-3 at an estimated
concentration below the quantitation limit. No other volatile constituents
were detected in SS-3.
• Pyrene was the only semivolatile detected in SS-3, at an estimated
concentration of 9 ^ig/kg.
• PCB/pesticide concentrations were below the method detection limits in
SS-3.
• All metal concentrations in SS-3 were within the background range.
AREA F
Surface soil samples were not collected in Area F.
AREA G
Surface soil sample SS-9 was collected within Area G and SS-15 was collected
to the east of Area G as illustrated in Figure 13E. Results of the TCL/TAL analyses
are discussed as follows:
VOCs were all below the method detection limit in SS-9 and in SS-15.
• Area G surface soil semivolatile results are discussed as follows:
DRAFT 50 April 29, 1993
1,4 dichlorobenzene was detected in SS-9 at 84 /xg/kg.
Eighteen semivolatile constituents were detected in SS-15 with
concentrations ranging from 29 /xg/kg of 2-methylnaphtalene to
4200 jig/kg of pyrene.
PCB/pesticide analytical results detected 4,4-DDE in SS-15 at a
concentration of 25 /xg/kg. PCB/pesticides were not detected in SS-9.
• Results of analyses for SS-9 and SS-15 are discussed as follows:
The metals detected in SS-9 which were above the background
range were silver, arsenic, chromium, cobalt, iron, nickel, lead,
and zinc. Concentrations ranged from less than two times
background (iron) to 18 times background (chromium).
The metals which were detected above background in SS-15 were
calcium, sodium, lead, and zinc. Concentrations ranged from less
than two times background (calcium, lead, and zinc) to
approximately three times background (sodium).
AREA J
Surface soil samples SS-4, SS-5, SS-6, and SS-24 were located in Area J on the
east side of the upper landfill access road as shown in Figure 13C. Results of the
TCL/TAL analyses are discussed as follows:
• VOCs were not detected above the method detection limit in Area J.
Eleven semivolatile constituents were detected in the Area J surface soil
samples as discussed below:
DRAFT 51 April 29, 1993
Two semivolatile constituents (bis(2-ethylhexyl)phthalate and
diethylphthalate) were detected in surface soil sample SS-6 at 210
Mg/kg and TO^ig/kg, respectively.
Bis(2-ethylhexyl)phthalate was detected in SS-5 at 23 jig/kg.
Ten constituents were detected in SS-4 with concentrations
ranging from 21 /zg/kg anthracene to 220 jig/kg fluoranthene.
• No PCB/pesticides were detected in the Area J surface soils.
• All metals in Area J surface soil samples were within the background
range with the exception of chromium (SS-4) and sodium (SS-6 & SS
24). The elevated metal concentrations were less than 2 times
background.
Recycling Area
Surface soil sample SS-22 was collected adjacent to soil boring B-22 as
illustrated on Figure 13F. Results of the analyses are as follows:
• VOCs were not detected in SS-22.
• Recycling area semivolatile analytical results identified three constituents
in SS-22 at concentrations ranging from 25 ^g/kg of fluoranthene to 79
/xg/kg of 1,4-dichlorobenzene.
• PCB/pesticide analyses detected gamma chlordane at a concentration of
0.46 ng/kg.
• All metals were detected within the background range with the exception
of sodium, which was approximately five times the background value.
DRAFT 52 April 29, 1993
Jones/Murray Property
Surface soil sample SS-20 was collected on the Jones/Murray property as shown
in Figure 4. Results of the TCL/TAL analyses are as follows:
• VOCs were not detected on the Jones/Murray property.
• Three semivolatile compounds were detected in SS-20 at concentrations
ranging from 37 ug/kg of fluoranthene to 150 /ig/kg of 1,4
dichlorobenzene.
PCB/pesticides were not detected in SS-20.
• Metals which were elevated above background concentrations included
arsenic, iron, manganese, nickel, vanadium, and zinc. All concentrations
were less than two times background.
Yahne Property
Surface soil sample SS-21 was collected from the Yahne property as shown in
Figure 4. Results of the sample are as follows:
• VOCs were below the method detection limit in SS-21.
• Semivolatile compounds were not detected on the Yahne property.
Pesticides detected in SS-21 included 4,4-DDT and 4,4-DDE at
concentrations of 3.9 fig/kg and 6.5 ngfcg, respectively.
• Metals detected above the background range in SS-21 included
aluminum, arsenic, chromium, iron, manganese, sodium, nickel, lead,
vanadium, and zinc. All concentrations were less than two times
background concentrations with the exception of lead and arsenic, which
were approximately two times the background concentration.
DRAFT 53 April 29, 1993
3.05.4 Discussion of Surface Soil Sampling Results
Surface soil sampling results provide the data required for the USEPA
Risk Assessment. In addition, analytical data correlated with the horizontal
extent of contamination as defined by the soil boring sampling program.
3.06 Soil Bonnes
Thirty-two soil borings (B-l through B-32) were installed at the Barkhamsted
Site to characterize the nature and horizontal and vertical extent of contamination in
several of the previously defined areas of investigation (Areas A, B, C, D, E, G, J, L,
Recycling Area, Previously Cleared Area #1). Soil gas surveys in Areas H and K. did
not indicate the need for soil boring installation in these areas. In addition, the
electromagnetic geophysical survey indicated that fill did not exisfln Area H. The
locations of the soil borings are illustrated on Figure 4. In addition, the location of
each soil boring within individual areas of investigation is depicted in Figures 13A
through 13F.
A total of 24 soil borings were installed within the areas of investigation based
upon existing information discussed in FSP Section 2.02.4. In accordance with the
provisions of the FSP, eight additional soil borings were installed based upon results
of the Phase 1A soil gas survey and geophysical surveys. The results of the soil gas
survey are discussed in Section 3.03 of this report. The following describes the
methods of the soil boring installations and results of the analyses performed.
DRAFT 54 April 29, 1993
3.06.1 Methods
Soil borings were completed in accordance the FSP procedures in
Appendix FSP-C. Borings were installed using hollow stem auger drilling
techniques. ASTM Method D-1586-84 was utilized to obtain continuous
samples of subsurface materials using a 2-foot long, 2-1/2 inch outside diameter,
split barrel sampler with a 140-lb hammer. Upon retrieval of the sampling
barrel, the samples were visually inspected and logged by the supervising
hydrogeologist. Soil boring logs are included in Appendix D.
Upon collection, the soil samples were divided with one portion being
placed into pre-cleaned 4-oz sample containers for VOC analysis, and a second
portion was placed into a glass container and covered with aluminum foil for
PID screening. Results of the PID screening are included on the soil boring
logs (Appendix D). The remaining sample was placed into a 1-liter amber jar.
Based upon the results of PID screening and visual differentiation between
naturally occurring and waste materials, a minimum of one sample per boring
was submitted to the laboratory for TCL/TAL analysis. A summary of soil
boring elevations, depths, sampled intervals, and first encountered ground water
is included in Table 7.
Initially, soil borings were advanced to the top of the water table. If the
water table was encountered less than 10 feet below grade, the soil borings were
advanced to a minimum depth of 10 feet or until naturally occurring soils were
encountered.
Subsequent to soil boring completion, the boreholes were backfilled with
a Portland cement/bentonite grout below the water table, and a mixture of soil
DRAFT 55 April 29, 1993
cuttings and Portland cement above the water table. Residual soil cuttings were
placed in DOT approved 55-gallon drums and staged in the borrow area in the
southern portion of the RRDD#1 property.
3.06.2 Field Modifications
Methods and locations outlined in the FSP and in the Additional Soil
Boring Technical Memorandum were modified in the field as discussed below.
• Soil borings B-31 and B-32, which were additional soil borings based
upon the soil gas survey results, were located in areas inaccessible to
drill rigs due to the steep grade of slopes in those locations. These soil
borings were advanced using a hand auger to 1 ft to 2 ft below grade.
A stainless steel spoon was used to remove a thin layer of soil which
was in contact with the hand auger, and the remaining sample was placed
into the appropriate sample containers.
• Only two of the four samples collected in boring B-29 (4 to 6 ft and 6
to 8 ft) were submitted for VOC analyses due to insufficient sample
recovery.
• Due to insufficient split spoon sample recovery in boring B-13, a second
soil boring (B-13A) was drilled adjacent to B-13 to acquire a sample.
• A sample from boring B-10 (2 to 4 ft) was submitted for VOC analysis
only due to insufficient sample recovery.
• Due to difficult drilling conditions, two soil borings were installed at the
B-17 and B-19 locations, and three soil borings were installed at the B
18 location (See Table 7).
DRAFT 56 April 29, 1993
Three soil borings (B-21, 21 A, & 2IB) were attempted in the vicinity of
boring B-21. Due to difficult drilling conditions, only soil boring B-21B
was completed successfully.
• Soil boring B-23 was not advanced to the water table due to difficult
drilling conditions. The boring was terminated at 17.4 ft after two
attempts.
3.06.3 Results
Each soil sample was shipped to Pace Laboratories, Inc in Wappingers
Falls, NY utilizing approved chain-of-custody procedures and analyzed for the
TCL/TAL parameters listed in Table 5. Analytical results for volatiles,
semivolatiles, pesticides/PCBs and inorganics are summarized in Tables 8A
through 8D, respectively. The discussion of soil boring sample results with
respect to the objectives of each soil boring are discussed below.
In addition to assessing soil boring analytical data as compared to
background data, the data were compared to levels in Table 9 which presents
soil contaminant action levels presented in the USEPA document "RCRA
Corrective Action for Solid Waste Management Units (SWMUs) at Hazardous
Waste Management Facilities".
Background Borings
Soil borings B-l and B-2 were completed to assess background
conditions at the site. Locations of the soil borings are depicted on Figures 4
and 13 A.
DRAFT 57 April 29, 1993
Background VOCs levels in B-l and B-2 were below the method
detection limit.
Bis(2-ethylhexyi)phalate was detected in B-l and B-2 at 380 ng/kg and
580 ^g/kg. respectively.
• Methoxychlor was detected in boring B-l at an estimated concentration
of 5.4 /ig/kg. which is below the quantitation limit. PCB/pesticides were
not detected in boring B-2.
• Background metal concentrations indicate consistent results for both B-l
and B-2. The concentrations provide a range in which to compare metal
concentrations detected in soils at other locations at the Barkhamsted
Site. Beryllium concentrations exceeded the USEPA action level of 0.2
mg/kg in all soil borings except B-20, B-22, and B-29. However, all
concentrations were below the laboratory quantitation limits.
The geological conditions encountered in B-l and B-2 suggest an
environment undisturbed by landfill activities. The analytical results in borings
B-l and B-2 establish a reliable base of background soil conditions with which
to compare suspected source area volatile, semivolatile, pesticide/PCB and metal
concentrations.
AREA A
Soil borings B-8, B-9, B-10, B-l l , B-l2, B-13, B-14 were installed
within and around the periphery of the suspected metal grindings waste disposal
area. In addi t ion to evaluating the vertical and horizontal extent of potential
contamination, the soil borings were used to evaluate whether the geophysical
anomalies in this area were due to subsurface conditions or surface metallic
DRAFT 58 April 29. 1993
debris. The locations of the soil borings are shown in Figure 13B. Multiple
samples were collected from borings B-9, B-10. B - l l , B-12. and B-14 as
summarized in Table 7 to better characterize the nature of the subsurface
conditions this vicinity. Results of these analyses are as follows:
• The following summarizes the highest concentrations of VOCs detected
in Area A: The compound 2-butanone was detected in boring B-9 (8.5
to 10.5 ft) at 35 /xg/kg; acetone was detected in B-12 (9 to 10 ft) at 590
/ig/kg; carbon disulfide was detected in boring B-8 (10 to 11 ft) at 29
Mg/kg: chlorobenzene was detected in B-12 (4 to 6 ft) at 500
ethylbenzene was detected in boring B-10 (2 to 4 ft) at 7600 n
toluene was detected in boring B-12 (9 to 10 ft) at 310 ^g^g
— xylenes were detected in B-10 (2 to 4 ft) at 34,000 ng/kg. voc
concentrations did not exceed USEPA action limits (Table 9).
• As indicated in Table 8B, 28 semivolatile constituents were detected in
soil borings B-8 through B-14. The highest detected concentration was
phenol at 6300 ^tg/kg in soil boring B-14 (2 to 4 ft). VOC
concentrations did not exceed USEPA action limits.
The PCB/pesticide analyses detected PCB Aroclor 1248, PCB Aroclor
1254, aldrin, alpha-chlordane, 4,4-DDD 4.4-DDE, 4,4-DDT. endnn
ketone, gamma-chlordane, endosulfan sulfate, and heptachlor epoxide.
Concentrations ranged from 1.6 Mg/kg of alpha-chlordane in B-12 (4 to
6 ft) to 6100 pg'kg of PCB Aroclor 1248 in B-12 (0 to 2 ft). PCBs (46
/xg kg of Aroclor 1254) were also detected in B-9 (8.5 to 10.5 ft);
however, results from other borings in Area A suggest these constituents
DRAFT 59 April 29, 1993
are isolated. The PCB concentration in B-12 (0 to 2 ft) exceeded the
USEPA action level of 90jxg/kg. The remaining PCB/pesticide
constituents were below the USEPA action limits.
Area A metal concentrations are discussed as follows:
Mercury was detected in boring B-10 (0 to 2 ft) at 0.72 mg/kg,
which is 18 times the quantitation limit. Mercury was also
detected in B-12 (4 to 6 ft) at 0.13 mg/kg, and B-14 (2 to 4 ft) at
0.19 mg/kg. Mercury was not detected in the background
samples.
Cadmium was detected in soil borings B-8 (10 to 11 ft), B-10 (0
to 2 ft), B-12 (9 to 10 ft), and B-14 (2 to 4 ft). The highest
detected concentration was 1.7 mg/kg, approximately two times
the quantitation limit, in boring B-10. Cadmium was not detected
in the background samples.
The highest metal concentrations were detected in soil borings B
9 and B-10. These metals included silver, aluminum, barium,
beryllium, cobalt, chromium, iron, mercury, potassium,
magnesium, manganese, sodium, nickel, lead, and antimony. The
elevated concentrations ranged from less than the quantitation
limit (antimony) to 289 times background (chromium).
The highest copper concentration in Area A was detected in
boring B-12 (9 to 10 ft) and is 484 times the background concen
trations.
DRAFT 60 April 29, 1993
Figure 14 illustrates the location of geologic cross section A-A. which is
presented as Figure 15. As indicated in the boring logs in Appendix D and
geologic cross section A - A'(Figure 15), the thickness of fill in the vicinity of
Area A ranges from 9 ft in B-l l and B-13 to 14 ft in B-8. The fill contained
refuse which is comprised of newspaper, shingles, metal pins, copper wire,
plastic, rubber tires, and styrofoam. The presence of subsurface metal wire, pins,
and shavings confirms that the geophysical anomalies discussed in the LFI
Summary Report (O'Brien & Gere, 1992) were due to subsurface ferrous
material. Based upon the results of the soil boring installations, Area A can be
confirmed as a former refuse disposal area.
The presence of metal pins and debris in the soil borings demonstrates
that the geophysical surveys in this vicinity were detecting subsurface metal.
However, results of the soil borings indicate the this metal waste is present in
discrete quantities. Analytical results indicate low concentrations of VOCs,
semivolatiles. and PCB/pesticides are present. Given the analytical results, the
proximity of Area A to the landfill, past landfill activities and the low analytical
concentrations. Area A is not a source area that should be addressed separately
from the overall landfill disposal area.
AREA B
Soil borings B-15, B-16, B-18, B-20, and B-31 (Figure 13B) were
installed around and within the suspected drum crushing area (Area B) to
evaluate if residual contamination from the drum crushing operation remained
in the soils. In addition, borings B-16 and B-18 were installed within a potential
metallic anomal> identified during the LFI geophysical surveys. Boring B-31
DRAFT 61 April 29, 1993
is an additional soil boring installed in the vicinity of Phase 1A soil gas point
LISG-106AB (Figure 13A) to aid in characterizing this suspected source area.
Table 7 summarizes the soil boring depths, sampled intervals, and depth to
ground water. Results of the TCL/TAL analyses are as follows:
• The highest detected VOCs in Area B were acetone at 160 ^g/kg in
boring B-15 (4 to 6 ft); and 2-butanone at 76 ngfkg in boring B-16 (14
to 16 ft). VOC concentrations in Area B were below the USEPA action
levels (Table 9).
• Nine semivolatile constituents were detected in Area B ranging from 28
/xg/kg of phenanthrene in B-31 (1 to 2 ft) to 220 /xg/kg of bis(2
Ethylhexyl)phthalate in B-31 (1 to 2 ft). Semivolatiles concentrations
were below the USEPA action levels (Table 9).
• All PCB/pesticide concentrations were below the quantitation limits.
• Elevated concentrations of metals were found in each soil boring, and are
discussed below:
Boring B-18 (4 to 6 ft) detected elevated concentrations of silver,
aluminum, barium, beryllium, cobalt, chromium, copper, iron.
potassium, magnesium, manganese, nickel, vanadium, and zinc.
Concentrations of the above metals were all approximately two
to three times background concentrations.
Lead was detected in boring B-31 (1 to 2 ft) at 13.8 mg/kg,
approximately three times background concentrations.
Figure 14 shows the location of geologic cross section B-B1 . As depicted
in geologic cross section B-B1 (Figure 16). the fill in Area B consists
DRAFT 62 April 29, 1993
predominantly of silt and sands intermixed with wood chips and other organic
matter (roots, branches, etc). Area B may encompass a portion of the former
stump dump which was once located in the vicinity of the recycling area. The
thickness of fil l across Area B ranges from 9 ft in B-18 to 18 ft in B-16. With
the exception of a metal fragment that was present in boring B-15 at 5.25 ft,
subsurface ferrous material was not encountered in this vicinity, indicating the
LFI geophysical anomaly was due to surface metal.
Very low levels of VOCs, semivolatiles, and PCBs/pesticides were
detected in Area B. indicating that residual contamination from the suspected
former drum crushing operation does not exist in this area. The analytical and
geological characterization of Area B indicates that Area B is not a source area
that needs to be addressed separately from the landfill disposal area.
AREA C
This area was identified during the LFI as a suspected landfill disposal
area. Soil borings B-17, B-19, and B-21 were installed within Area C (Figure
13B) to evaluate the extent of potential contamination and to determine whether
the geophysical anomalies observed during the LFI were due to subsurface
conditions or surface interference. In addition, boring B-30 is an additional soil
boring that was installed adjacent to Phase 1A soil gas point SG-11Z which
exhibited a slightly elevated soil vapor result. A summary of soil boring depths
and sampled intervals is included in Table 7. Results of the TCL/TAL analyses
are as follows:
DRAFT 63 April 29. 1993
Volatile constituents detected at the highest concentrations included
acetone at 190 /xg/kg and 2-butanone at 24 jig'kg in B-17 (13 to 15 ft).
Volatile concentrations were below the USEPA action levels (Table 9).
Twelve semivolatile constituents were detected in Area C ranging from
9 /xg/kg of fluorene in B-17 (10 to 12 ft) to 1300 /xg/kg of bis(2
ethylhexyl)phthalate in B-30 (5 to 7 ft). Semivolatile concentrations
were below the USEPA action levels (Table 9).
Pesticides detected in Area C included 4,4-DDD, 4,4-DDE. endrin
ketone. and heptachlor epoxide. The highest concentration detected was
11.0 fig/kg of 4,4-DDE in B-19 (2 to 4 ft). PCB^Pesticide
concentrations were below the USEPA action levels (Table 9).
The metal concentrations in each boring were typically one to three times
above background values.
Mercury was detected in boring B-19 (2 to 4 ft) at 0.15 mg.'kg.
Lead was detected in boring B-19 (2 to 4 ft) at 346 mglcg,
approximately eight times background concentrations.
Selenium was detected in soil borings B-17 (10 to 12 ft). B-17
(13 to 15 ft) and B-30 (5 to 7 ft). Concentrations ranged from
0.21 mg/kg (B-17, 10 to 12 ft) to 0.36 mg/kg (B-17, 13 to 15 ft).
which are all below the quantitation limit.
Thallium was detected in boring B-30 (5 to 7 ft) at 0.23 mg.'kg.
\ \h ich is below the quantitation limit.
Similar to the subsurface conditions encountered in Area B, the fill in
Area C consists of predominantly silt and sands intermixed with wood chips and
DRAFT 64 April 29. 1993
other organic matter (roots, branches, etc). This fill may be the result of the
stump dump which existed in the vicinity of the recycling area. The fill ranged
in thickness from 4 ft in B-19 to 11 ft in B-17.
Although Area C has been impacted from landfill activities, the primarily
organic nature of the fill combined with low levels of VOCs, semivolatiles,
PCB/pesticides and metals indicates that Area C is not a significant source area.
The fill encountered in Area C is limited to the eastern portion based upon soil
gas. geophysical data, and soil borings.
AREA D
This area was identified as a suspected liquid waste disposal area. Soil
boring B-7 was installed north of Area D, adjacent to LFI soil gas point LISG
78 (Figure 13C) to evaluate the potential presence of a source area in this
vicinity. A summary of soil boring sampling data are included in Table 7.
Results of the analyses are as follows:
• VOCs were not detected above the method detection limit in soil boring
B-7.
• Semivolatiles were not detected in B-7.
• PCB/pesticides were not detected above the method detection limit in
boring B-7.
• Elevated concentrations of metals, as compared to background, were
detected in B-7. These metals included silver, aluminum, arsenic,
beryllium, cobalt, chromium, iron, sodium, lead, vanadium, and zinc.
Concentrations ranged from less than two times background (cobalt) to
DRAFT 65 April 29, 1993
five times background (arsenic). However, both arsenic and cobalt were
below the quantitation limit.
All Area D detected TCL/TAL analytes were below USEPA action levels
(Table 9).
Subsurface conditions indicated from the B-7 boring log (Appendix D)
did not reveal refuse or materials originating from landfill activities or the
presence of liquid waste, indicating the limits of fill do not extend into this area.
The low analytical results indicate that Area D in the vicinity of boring B-7 is
not a source area.
AREA E
This area comprises Sedimentation Basin No. 2, and was also identified
as a possible area of waste disposal and former drum storage. Soil boring B-3
was installed in the vicinity of LFI soil gas point LISG -111, and boring B-29
was added adjacent to soil gas point SG-62DA (Figure 13C). These soil borings
were installed to evaluate a potential source area in Area E. In addition, both
soil borings were used to evaluate the potential presence of buried metallic
waste in this vicinity. As summarized in Table 7. one soil sample from B-3 and
four samples from B-29 were selected for TCL/TAL analysis. Results of these
analyses are as follows:
• VOC analytical results for Area E soil borings are discussed as follows:
VOCs were below the method detection limit in boring B-3.
Methylene chloride was detected in B-29, with the highest
concentration of 98 ^ig/kg detected in the 2 to 4 ft interval.
DRAFT 66 April 29, 1993
Acetone was detected in all four B-29 samples, ranging from 9
Mg^kg (6 to 8 ft) to 1200 jig/kg (2 to 4 ft).
Ethylbenzene, toluene, and xylenes was detected in B-29 between
0 ft and 6 ft. The highest concentration of toluene (260 /xg/kg)
was detected in B-29 (2-4'). Xylenes were detected between 0 ft
and 4 ft with the highest concentration of 120 jig/kg detected in
the 0 to 2 ft sample. Ethylbenzene concentrations range from 1
Mg/kg in the 4 to 6 ft sample to 67 jig/kg in the 0 to 2 ft sample.
VOC concentrations in Area E did not exceed USEPA action
levels.
Semivolatiles detected in the Area E soil borings are discussed as
follows:
Three semivolatile compounds were detected in B-3, with
concentrations ranging from 12 /xg/kg °f diethylphtalate to 55
Mg/kg of 1,4-dichlorobenzene.
Seven semivolatile constituents were detected in boring B-29
Concentrations ranged from 49 /xg/kg of 1,4-dichlorobenzene (6
to 8 ft) to 3900 /xg/kg of 2-methylphthalene (0 to 2 ft).
Semivolatile concentrations were below the USEPA action levels
(Table 10).
PCB/pesticide concentrations were below the detection limit in B-3 and
B-29.
Metal concentrations in Area E soil borings are discussed as follows:
DRAFT 67 April 29, 1993
Slightly elevated concentrations of barium and cobalt were
detected in B-3. The metal concentrations are both less than two
times background concentrations.
The bulk of metal concentrations which exceeded background in
boring B-29 were detected in the 0 to 2 ft interval and included
silver, arsenic, barium, cobalt, chromium, copper, iron,
manganese, nickel, lead, vanadium and zinc. The elevated
concentrations ranged from two times background (vanadium) to
316 times background (chromium).
As indicated from the boring logs in Appendix D, the geologic conditions
in this vicinity are similar to background conditions. However, a surficial fill
layer (0 to 2 ft) of black stained silt with ball bearings, metal pins, thread, and
wood chips is present at B-29. This fill is interbedded with gravelly sands
which grade into a black stained silt layer at 4 ft to 4.5 ft, where the water table
was encountered.
Results of the soil borings installed in Area E indicate a potential source
area does not exist in the vicinity of B-3. Buried metallic waste was
encountered in boring B-29, which is confirmed by the elevated metal
concentrations. However, the metals are predominantly at the surface, indicating
that metals have not migrated downward. Although Area E has been impacted
by landfill activities, the limits of fill should not be extended to encompass Area
E. The lou l e v e l s of VOCs, semivolatiles and PCB/pesticides associated with
the uaste indicate that this material is not a source of contaminants.
DRAFT 68 April 29, 1993
AREA F
Area F was previously identified as a stained soil area. Soil boring B-27
was an additional soil boring installed based upon the results of the Phase 1A
soil gas survey. Boring B-27 was installed in the western portion of Area F
(Figure 13D) adjacent to soil gas point SG-20D. The summary of soil boring
depths and sampled intervals is included in Table 7. Results of the TCL/TAL
analyses are as follows:
• VOCs were not detected in B-27.
Nine SVOC constituents were detected in boring B-27 (0 to 2 ft).
Concentrations ranged from 19 /ig/kg of benzo(k)fluoranthene to 530
Mg/kg of bis(2-chloroethyl) ether.
• PCB/pesticide analytical results for boring B-27 indicated that 4.4-DDE
and methoxychlor were detected at estimated concentrations below the
quantitation limit.
• Metals detected in Area F included arsenic, barium, chromium, copper,
iron, potassium, magnesium, sodium, lead, vanadium, and zinc. Elevated
concentrations ranged up to two times background (magnesium).
• TAL/TCL analytical concentrations detected in Area F did not exceed
USEPA action levels (Table 9).
The boring log in Appendix D indicates that refuse was not encountered
in B-27. indicating that the landfill disposal area limits do not extend into Area
F. Trace le\els of pesticides, semivolatiles and elevated metals are similar to
site background conditions. Based upon these results, Area F is not considered
a contaminant source area.
DRAFT 69 April 29. 1993
AREA G
This area was previously identified as the location of a metal grindings
waste cell and a drum storage and handling area. Soil borings B-26 and B-28
were installed within and adjacent to Area G in the vicinity of soil gas points
SG-33C and SG-25C, respectively. These were additional soil borings based
upon the results the Phase 1A soil gas survey. The objective of these soil
borings was to further investigate anomalous soil gas results and identify
potential contamination within Area G. Locations of these soil borings are
shown on Figure 13. Table 7 summarizes boring depths, depth to ground water,
and intervals sampled for laboratory analysis. Results of the TCL/TAL analyses
are as follows:
VOCs were not detected in B-26 and B-28.
• Semivolatile results are discussed as follows:
Bis(2-ethylhexyl)phthalate was detected in B-26 (8 to 10 ft) at
180 /zg/kg and in B-28 at 120 /xg/kg.
Di-n-butylphthalate was detected in B-26 (8 to 10 ft) at 48 /ug/kg
and in B-28 at 45 jig/kg
• PCB/pesticides were not detected in the Area G soil borings.
• Results of metal analyses are as follows:
Boring B-26 (8 to 10 ft) detected potassium and zinc at
concentrations less than two times background. All other metal
concentrations were within the established site background range.
All detected metals, with the exception of calcium, were higher
than background in boring B-28 (6 to 8 ft). The elevated
DRAFT 70 April 29, 1993
concentrations ranged from less than the quantitation limit
(selenium) to two times background (zinc).
• TCL/TAL analyte concentrations detected in Area G did not exceed
USEPA action levels (Table 9).
The boring logs in Appendix D indicate subsurface conditions were
similar to background with the exception that wood chips were encountered in
B-28 up to 2 ft below ground surface. No other refuse was identified in this
vicinity. These conditions, taken in conjunction with the low levels of
semivolatiles and metals along with the lack of EM-31 and magnetometer
anomalies, indicate that the portion of Area G which is not located on the
landfill is not a source area.
AREA J
Based on prior review of aerial photos, this area was identified as a
possible area of unspecified waste disposal or handling. Soil borings B-4, B-5,
and B-6 were located in Area J on the east side of the upper landfill access road
to assess the potential presence of a VOC source area. Soil boring B-25 is an
additional boring located adjacent to Phase 1A soil gas point SG-37DC (Figure
13C). A summary of soil boring depths and sampled intervals is included in
Table 7. Results of the TCL/TAL analyses completed in Area J are as follows:
• Results of VOC analyses indicate the following:
\cetone was detected in soil boring B-4 (2 to 4 ft) at 180 /ig/kg
and in boring B-25 (2 to 4 ft & 4 to 6 ft) at 4 /xg/kg and 73
^g kg. respectively.
DRAFT 71 April 29, 1993
B-25 contained BTEX constituents benzene, ethylbenzene. and
toluene. The highest detected concentration was 7 y.g'kg of
toluene in B-25 (4 to 6 ft).
• Ten semivolatile constituents were detected in the Area J soil borings.
Concentrations ranged from 7 jig/kg of chrysene in B-6 (0 to 2 ft) to 510
Atg/kg of bis(2-Ethylhexyl)phthalate in boring B-4 (2 to 4 ft).
• Results of the pesticide/PCB analyses are as follows:
PCB/pesticides were not detected in borings B-4, B-5, and B-6.
The compounds 4,4-DDD, 4,4-DDE, and 4,4-DDT were detected
in B-25 (2 to 4 ft) at estimated concentrations below the
quantitation limit.
• Results of Area J metal analysis are discussed below:
Although elevated concentrations of some metals, as compared to
background, were observed in all soil borings, boring B-4
contained the bulk of these concentrations and included silver.
aluminum, arsenic, beryllium, chromium, copper, iron.
magnesium, sodium, nickel, antimony, selenium, and vanadium.
The elevated constituents ranged from less than the quantitation
limit (antimony & selenium) to approximately six times
background for arsenic. However, the detected arsenic
concentration was less than the quantitation limit.
Lead \\as detected in B-25 (2 to 4 ft) at approximately 11 times
the site background concentration.
DRAFT 72 April 29, 1993
The TCLTAL analyte concentrations detected in Area J did not exceed
USEPA action levels (Table 9).
The boring logs in Appendix D indicate geologic conditions similar to
the observed background conditions. Boring B-25 exhibited fill materials
(thread and wood chips) to approximately 6 ft. Trace quantities of VOCs,
pesticides, and semivolatiles were detected throughout Area J. Based upon the
soil boring results. Area J has been impacted by landfill activities but is not
considered a source area. The limits of the landfill should not extend to
encompass Area J.
AREA H
Soil borings were not installed in Area H based upon the results of the
geophysical and soil gafsurveys (Section 3.02 and 3.03).
AREA K
Soil borings were not installed in Area K based upon the results of the
soil gas survey (Section 3.03).
AREA L
Soil borings B-23 and B-24 were installed within Area L to evaluate the
potential of a source area existing within the landfill septic field area. The
locations of the soil borings are shown on Figure 13F. A summary of soil
boring elevation, depths, and sampled intervals is presented in Table 7. Results
of TCL/TAL analyses performed on samples from Area L are as follows:
• Vo la t i l e constituents were below the method detection limit in Area L.
DRAFT 73 April 29, 1993
The semivolati le compounds di-n-butylphalate and bis(2
ethylhexy])phthalate was detected in B-24 at estimated concentrations
below the quantitation limit.
PCB/pesticides were not detected in Area L.
• The detected metal constituents in boring B-24 were within the
established background range.
Boring B-23 detected the following metals above the background
range: silver, aluminum, barium, beryllium, cobalt, chromium,
copper, iron, potassium, magnesium, manganese, sodium, nickel,
lead, vanadium and zinc. Each elevated metal concentration was
less than two times the background concentration.
• TCL/TAL analyte concentrations detected in Area L were below the
USEPA action levels (Table 9).
Logs of the soil borings in Area L indicate that background geologic
conditions exist in this vicinity. Refuse was not encountered in this area.
indicating this area should not be included within the limits of fill. Lack of
detectable VOCs, PCBs/pesticides, low levels of semivolatiles and elevated
metals indicate that Area L is not a contaminant source area.
Recycling Area
Soil borings B-21 and B-22 were installed in the vicinity of the recycling
area to evaluate potential impacts from operations in this vicinity (Figure 13F).
The summar) of soil boring depths and sampled intervals is presented in Table
7. Results of FCL TAL analyses from samples collected in this area are as
follows:
DRAFT 74 April 29. 1993
• VOC's were not detected in the recycling area.
• The semivolatile compound 1,4-Dichlorobenzene was detected in B-21
(8 to 10 ft) at 100 /ig/kg- and B-22 (8 to 10 ft) at 64 /ig/kg.
• PCB/pesticides were below the detection limit in the recycling area soil
borings.
• Recycling area metal analyses results are discussed below:
Soil boring B-21 contained the most metal constituents which
were greater than established background values. These
constituents included silver, aluminum, arsenic, barium, beryllium,
cobalt, chromium, copper, iron, magnesium, sodium, nickel, lead,
vanadium, and zinc. These elevated metals concentrations did not
exceed two times the background levels.
Antimony was detected above the site background range;
however, the concentration (2.4 mg/kg) was less than the
quantitation limit.
TCL/TAL analyte concentrations detected in the recycling area were
below the USEPA action levels (Table 9).
Refuse, including plastic and glass, was encountered within the first 2
feet below the ground surface and is the result of scattered refuse from recycling
activities, rather than disposal activities. The geology in this vicinity is similar
to background conditions, indicating the limits of the landfill disposal area do
not extend to the recycling area. Low levels of VOCs, semivolatiles and
elevated metal concentrations were detected in the recycling area. Based upon
these results, the Recycling Area is not a contaminant source area.
DRAFT 75 April 29, 1993
Previously Cleared Area #1
Soil boring B-32 was an additional soil boring installed based upon the
results of the Phase 1A soil gas survey. Soil boring B-32 was installed south
of previously cleared area #1 near soil gas point SG-49CD (Figure 13D). A
summary of the soil boring depth and sampled intervals is included in Table 7.
Results of TCL/TAL analyses performed on samples collected from this area are
as follows:
• VOCs were not detected in B-32.
• The semivolatile compounds bis(2-ethylhexyl)phthalate and di-n
butylphthalate were detected in B-32 at 130 /ig/kg and 38 iLgfag,
respectively.
• PCB/pesticides were not detected in boring B-32 above the method
detection limit.
• Metals detected above background included aluminum, beryllium, iron,
selenium, vanadium, and zinc. The concentrations ranged from less than
the quantitation limit (selenium) to less than two times background
(aluminum).
• The TCL/TAL analyte concentrations detected in previously cleared area
#1 were below the USEPA action levels.
The boring log in Appendix D indicates that refuse was not encountered
in B-32. Trace le\els of semivolatiles and elevated metals are similar to site
background condi t ions . Based upon these results, previously cleared area #1 is
not considered a source area, and shall not be considered part of the landfill
disposal area
DRAFT 76 April 29, 1993
3.07 Geotechnical Properties of Soils and Waste Materials
Geotechnical data on the properties of site soils and waste materials will be
required during preparation of the FS to evaluate stability and settlement as well as
material handling properties in conjunction with the development of remedial
alternatives. Geotechnical data sufficient to permit the evaluation of alternatives
proceed was developed during the Phase 1A Site Characterization.
A total of 32 test borings were installed during field work associated with the
Phase 1A Site Characterization. It should be noted that two of the test borings, B-31
and B-32, were installed using a hand auger and were therefore not utilized in
developing information presented in this section. Based on findings of previous
investigations and information from the test borings installed during the initial site
characterization, the stratigraphy in the vicinity of the landfill consists, from top to
bottom, of the following:
Fill;
• Ice contact deposits;
• Lodgement till;
• Bedrock;
Refuse is present above these strata in the landfill portion of the site. A more detailed
discussion of site stratigraphy is presented in Section 4.
A preliminary determination of the horizontal limits of refuse was made based
on an analysis of aerial photographs, historical records, personal interviews and site
topography. In order to more accurately evaluate the horizontal limits of the landfill.
29 test pits, or trenches, were excavated along the landfill perimeter utilizing a backhoe.
Excavation was typically initiated in clean areas and advanced toward areas suspected
DRAFT 77 April 29, 1993
of having been filled. Upon encountering the edge of fill in a given test pit. the
location was staked and the test pit backfilled. The locations of test pits installed
during the Phase 1A Site Characterization, along with the horizontal limits of the
landfill developed based on the test pit results, are shown on Figure 17. It was not
possible to excavate a test pit at location #15 due to deep snow and steep slopes. The
toe of the steep slope was visually identified as representing the edge of refuse in this
area. Based on the results of the test pits and soil borings, the total estimated area
covered by refuse is approximately 13.3 acres.
Monitoring well MW-119F was installed within the limits of the refuse at the
location shown on Figure 18. Refuse was encountered in the boring for MW-119F to
a depth between 42 and 50 feet below grade. A refuse depth between 40 and 50 feet
at this location corresponds with refuse depths which may be inferred from
interpretation of site topography. The surface of the landfill in the vicinity of MW
119F is approximately 9 feet below the highest elevation of the landfill when the
topographic survey was performed in 1990. This indicates that the greatest thickness
of refuse in this vicinity at the time of the topographic survey was on the order of 60
feet. A closure plan developed in 1992 by Fuss & O'Neill on behalf of RRDD#1 for
compliance with CTDEP regulations indicates that the top of the landfill may receive
between 5 and 10 feet more refuse prior to site closure.
Standard penetration testing was performed during installation of MW-119F and
the 32 test borings. The standard penetration number, N, is the total number of blows
of a 140-lb hammer f a l l i ng 30 inches required to drive a 2-foot sampling spoon 1 foot
after an inial 6-inch penetration. Empirical relationships have been developed relating
the value of N to structural properties of a material.
DRAFT 78 April 29. 1993
Standard penetration testing was performed periodically during installation of
MW-119F in the refuse. N values in material identified as refuse ranged from 25 to
77. The variation in N values reflect the variations in the nature of the refuse
encountered at a municipal landfill. According to the Foundation Engineering
Handbook (Winterkorn & Fang. 1975), if modeled as a soil, the N values indicate that
the refuse would behave as a medium to very dense sand with friction angles ranging
from 30° to in excess of 45°. If cohesive in nature, the refuse would behave as a very
stiff to hard clay with cohesive strengths ranging from 4,000 to 8,000 pounds per square
foot (psf).
According to the Handbook of Solid Waste Management (Wilson. 1977),
residential waste may have densities ranging from 3.3 to 27.8 pounds per cubic foot
(pcf) while industrial waste, excluding heavy metal scrap, may have densities ranging
from 1.9 to 90 pcf. Information presented in Foundation Engineering in Waste
Disposal Fills (Sowers, 1973) indicates that chopped wastes show effective strengths
similar to organic soils, with effective friction angles between 10°and 15° and cohesion
from 200 to 300 psf. Consultants working on stability of the Freshkills Landfill in
Staten Island, New York (the worlds largest landfill), have modeled refuse as having
unit weights ranging from 53 to 86 pounds per cubic foot (pcf), friction angles from 27°
to 38° and cohesion on the order of 300 psf (IT Corporation and others, 1992). The
range of values which have been reported for geotechnical parameters associated with
refuse reflect the heterogenous nature of municipal waste. In light of this discussion
and the nature of \\aste deposited at the Barkhamsted Site, it is proposed that
parameters similar to those ultimately selected for use in the Freshkills study be utilized
DRAFT 79 April 29, 1993
in modelling which will be performed to evaluate remedial alternatives. This approach
results in using a unit weight of 70 pcf, a friction angle of 33°, and a cohesion of 300
psf. These values are conservatively within the ranges of values indicated by field test
results and reported in the literature.
As previously discussed 30 test borings from which geotechnical data can be
developed were installed at the Barkhamsted Site. Of these, 25 encountered fill
composed primarily of disturbed silty and sandy soil, with some extraneous material
such as wood chips, glass, plastic, rubber, paper, styrofoam, cans, brick fragments, and
copper wire. Where encountered, fill thickness ranged from 0.5 to 18 feet. Of the 82
standard penetration tests performed in material classified as fill, N values ranged from
2 to 182 with an average value of approximately 52, and a median value of
approximately 41. The analysis of N values indicate that the fill should be evaluated
as a dense, cohesionless soil. The median N value is indicative of a friction angle
ranging from approximately 38° to 43° according to information presented in
Foundation Engineering Handbook (Winterkorn & Fang, 1975). It is proposed that a
value of 38° be used for evaluation of remedial options. Information presented in So/7
Mechanics (Lambe & Whitman, 1969) indicates that dry unit weights for silty sand
typically range from 87 pcf to 127 pcf. These values will increase as the moisture
content of the material increases. Test boring logs indicate that the fill ranges from dry
to moist. Given the dense nature of the fill indicated by the N values and the presence
of moisture in some of the fill, a unit weight of 120 pcf is appropriate for use in
analyses to be performed in evaluating remedial alternatives.
Previous investigations and test borings installed for this investigation indicate
that the site is underlain by ice contact deposits which are in turn underlain by
DRAFT 80 April 29, 1993
lodgement till. From an engineering perspective, these materials may be considered as
a single unit. Till was encountered in 28 of the 30 test borings installed during this
investigation from which geotechnical data can be derived, as well as at the bottom of
the boring for MW-119F installed through the refuse. In these borings, a total of 115
standard penetration tests were performed with N values ranging from 4 to 205. The
average and median N value for the till is approximately 95. A total of nine samples
of the till were tested for the following parameters:
• Natural moisture content:
• Bulk (natural) soil density (unit weight);
Porosity: and
• Specific gravity.
These samples, in addition to other samples as described in Section 3.06, were also
tested for mechanical grain size analyses. The results of the analyses of these nine
samples are presented in Appendix C.
Natural moisture contents ranged from 9.1% to 32.1% with an average value of
15%. Unit weights ranged from 84.8 pcf to 125.6 pcf with an average value of 113.5
pcf. Values for porosity ranged from 24.8 to 48 with an average value of 33. Specific
gravities ranged from 2.61 to 2.73 with an average value of 2.7. The grain size
analyses performed on samples for which the other laboratory tests were performed
indicated between 27.3% and 77.5% passing a number 200 sieve with an average value
for these nine samples of 39% passing the number 200 sieve.
The values for the tested parameters are all within typical ranges which might
be expected for t i l l . The unit weight of 84.8 pcf is on the low end of the normal range
and the porosity of 48 is on the high end of the normal range. These values occurred
DRAFT 81 April 29, 1993
in the same sample which also had the highest natural moisture content. This
information indicates an anomalous condition in the tested sample. Based on the results
of the standard penetration testing and the results of the laboratory analyses, it is
recommended that the average values of parameters for which laboratory tests were
performed be utilized for subsequent evaluations.
According to information presented in the Foundation Engineering Handbook
(Winterkom & Fang. 1975), glacial till is often assumed to have a presumptive bearing
capacity between 8,000 to 24.000 pcf. The same reference indicates that N values in
excess of approximately 50 correlate with a cohesive strength of 8,000 psf in a clay
soil. In light of the high percentage of fines and the high N values, it is recommended
that the glacial till be modeled as a cohesive soil with a cohesive strength of 8,000 psf.
The final component of site stratigraphy is schist bedrock which is encountered
at depths ranging from 9 feet to 50 feet below grade. Given the high strength of
materials overlying bedrock, any geotechnical properties of bedrock required for
evaluation of remedial alternatives will be minimal and can be reasonably assumed from
literature values.
It should be noted that the approved FSP for the Barkhamsted Site called for the
monitoring of landfill settlement. This was to be accomplished by installing eight
settlement plates and surveying their elevations quarterly. During conduct of field work
associated with other elements of the FSP, it was observed that the area proposed for
installation of the settlement plates is currently receiving waste. As previously
discussed, the 1992 Closure Plan for the site indicates that the area proposed for the
installation of settlement plates will receive between 5 and 10 feet of additional refuse
prior to site closure.
DRAFT 82 April 29, 1993
In a letter to the USEPA dated February 10, 1993. O'Brien & Gere
recommended that, in light of continuing operations at the landfill, installation of
settlement plates be deleted from work to be performed in connection with the Phase
1A Remedial Investigation/Feasibility Study. O'Brien & Gere further proposed that
information presented in the literature be used for evaluation of likely landfill settlement
rates for purposes of evaluating remedial alternatives during the Feasibility Study. It
was also proposed that, if necessary, field data could subsequently be developed for
purposes of final design. By copy of a letter dated March 16, 1993, the USEPA
concurred that sufficient information may be available in the literature to evaluate likely
landfill settlement rates during the FS. However, in accordance with requirements in
that letter, a plan and schedule for obtaining site specific data for purposes of design
is to be developed by O'Brien & Gere and implemented subsequent to approval by
USEPA.
DRAFT 83 April 29, 1993
SECTION 4 HYDROGEOLOGIC INVESTIGATIONS
4.01 General
The objectives of the subsurface hydrogeologic investigations at the Barkhamsted
Site were to characterize the site hydrogeologic conditions, evaluate the potential for
contaminants from the site to enter the ground water system and migrate to potential
receptors, and to develop information to aid in the selection of appropriate remedial
alternatives.
The migration of contaminants in ground water to potential receptors is largely
controlled by the site hydrogeologic conditions. The Phase 1A Site Characterization
hydrogeologic investigations focused on characterization of the overburden and bedrock,
and assessed the hydraulic relationship between the various water bearing zones and
surface water bodies in the vicinity of the Barkhamsted Site. The P h a s e 1A
hydrogeologic investigations were designed to utilize and supplement the hydrogeologic
data collected by Fuss & O'Neill, Inc. in 1991 and summarized in the LFI Summary
Report.
4.02 Hvdrogeological Field Investigations
The objective of the monitoring well installation program was to characterize the
horizontal and vertical extent of ground water contamination and to evaluate the site
hydrogeology. The monitoring well network was also used to provide data for
estimating the volume of ground water in contact with the landfill material.
DRAFT 84 April 29, 1993
4.02.1 Ground Water Monitoring Well Installations
A total of seven overburden monitoring wells and 15 bedrock monitoring
wells were installed as part of the Phase 1A Site Characterization to supplement
the 31 existing ground water monitoring wells. A summary of newly installed
and existing monitoring well specifications is included in Table 4. The locations
of all site monitoring wells are shown in Figure 18. The monitoring well logs
are included in Appendix D.
As described in the FSP, the monitoring well locations were selected
based on existing hydrogeologic ground water quality data, and were designed
to screen various water bearing zones. The wells designated as F (fill), S
(overburden), B (shallow bedrock), I (intermediate bedrock), and D (deep
bedrock) evaluate ground water quality at various depths. The rationale for each
monitoring well location is provided in the FSP.
Methods
Overburden Monitoring Wells
Six overburden monitoring wells and one fill material monitoring well
(MW-113S through MW-118S, and MW-119F) were installed using 4 1/4 inch
inside diameter (I.D.) hollow stem augers (HSA) in accordance with FSP
Appendix FSP-F. During drilling, soil samples were collected continuously at
2-foot intervals utilizing 2-inch diameter split spoon sampling techniques in
accordance with ASTM Method D-l586-84.
Each overburden well was constructed with a 2-inch I.D. schedule 40
PVC well casing which was joined water tight using flush threads to a 10-ft
DRAFT 85 April 29, 1993
length of 2-inch I.D. Schedule 40 PVC 0.010-inch slotted well screen with a
PVC plug at the base. The well casing extended from the screened interval to
2 ft to 3 ft above the ground surface. The annular space between the well
screen and the borehole was filled with washed silica sand compatible with a
0.010-inch slot well screen extending from the base of the hole to a minimum
of 1 foot above the well screen. A bentonite pellet seal was installed above the
filter pack with a minimum thickness of 2 ft. Following installation of the
bentonite seal, a portland cement/bentonite grout was placed in the annular space
between the outside of the well casing and the borehole wall above the bentonite
seal. Each well was finished with a locking 6-inch protective steel casing which
was installed over the PVC casing.
Bedrock Monitoring Wells
Bedrock monitoring wells were installed using conventional air rotary
drilling techniques in accordance with the procedures presented in FSP
Appendix FSP-F. Each bedrock monitoring well was installed by initially
advancing a 10-inch diameter temporary casing to the top of bedrock. A 10
inch diameter borehole was then advanced through the temporary steel casing
approximately 5 ft into competent rock. A permanent 6-inch diameter, schedule
20, new carbon steel casing was installed through the 10-inch temporary casing
into the bedrock borehole, and was extended approximately 2 ft above ground
surface. The 6-inch steel casings were grouted in place with a Portland
cement/bentonite grout mixture as the temporary 10-inch steel casings were
DRAFT 86 April 29, 1993
removed. The grout mixture was allowed to cure a minimum of 12-hours prior
to proceeding with subsequent stages of well installations.
The 6-inch diameter borehole was then completed to a depth which either
produced ground water flow rates of at least 0.1 gallons per minute (gpm), or
in selected well nests (MW-101, MW-104, MW-106, MW-110, MW-111, and
MW-113), based upon the results of packer testing as discussed in Section
4.02.4.
During the drilling of fhe monitoring wells, formation samples were
collected at 5-foot intervals and at each formation change using a wire strainer.
Descriptions of each bedrock borehole are included in the boring logs in
Appendix D.
Bedrock ground water monitoring wells were constructed of 2-inch I.D.,
threaded, flush-joint, schedule 40 PVC well casing attached to 10-ft sections of
2-inch I.D., 0.010-inch slot size, schedule 40 PVC well screen. A washed silica
sandpack compatible with a 0.010-inch slot screen was installed from the bottom
of the borehole to at least 2 ft above the well screen. A bentonite pellet seal
with minimum thickness of 2 ft was installed on top of the sandpack. The
remainder of the annular space above the bentonite seal was filled with a
Portland cement/bentonite grout mixture by pumping the mix through a tremie
line. Each permanent 6-inch casing was fitted with a locking cover to complete
the well installations. As-built construction details of the bedrock monitoring
wells are included in Appendix D.
DRAFT 87 April 29, 1993
Field Modifications
The following field modifications resulted in deviations from procedures
presented in the approved FSP.
• The screened interval in monitoring well MW-113S does not extend
above the water table. Difficulty in identifying saturated conditions in
this vicinity resulted in the well screen being placed at the top of
bedrock, below the top of the water table.
• During installation of MW-113I and MW-106B, the temporary 10-inch
casings could not be retrieved from the subsurface, requiring that they be
left in place and cut flush with the ground surface, leaving the wells
triple-cased.
• An 8-inch temporary casing was installed to the top of bedrock during
the installation of MW-106B. This was due to the inability to advance
or retrieve the temporary 10-inch casing at this location as a result of
subsurface conditions.
Bedrock monitoring wells MW-111I, MW-117B, and MW-118B were
installed using a combination of mud rotary techniques and conventional
air rotary techniques due to difficult subsurface drilling conditions
consisting of cobbles and boulders, and the inability to maintain an open
borehole during overburden drilling. Mud rotary techniques were utilized
during the overburden drilling to install the 10-inch temporary casing to
the top of bedrock. Subsequent to installing the 10-inch temporary
casing, conventional air rotary techniques were utilized to complete
DRAFT 88 April 29, 1993
bedrock monitoring well installation. This modification was discussed
with and subsequently agreed to by the USEPA.
4.02.2 Monitoring Well Development
The overburden and bedrock monitoring wells were developed
following installation to remove fine grained sediments that may have
settled around the well screen during the drilling of each well so that the
screen is transmitting representative portions of the ground water.
Development of the overburden wells was completed by hand
bailing with stainless steel bailers. A length of new polypropylene rope
was utilized at each overburden well location, and the bailers were
decontaminated between overburden well locations in accordance with
the protocol presented in FSP Appendix FSP-D. Development consisted
of lowering the bailer to the bottom of each overburden well, gently
raising and lowering the bailer to agitate sediments, and then retrieving
the bailer to remove the sediment. Development of the overburden wells
ceased after a minimum of 2 hours, the well yielded relatively sediment
free water, and exhibited consistent field pH and specific conductance
measurements. Development water was contained and managed in
accordance with the protocol presented in FSP Appendix FSP-A.
The bedrock ground water monitoring wells were developed with
a Grundfos Redi-Flo 2 submersible pump (a Brainard-Kilman hand pump
was utilized on MW-113B and MW-117B due to a malfunction of the
Grundfos). During development, field measurements of pH, specific
DRAFT 89 April 29, 1993
conductance (^iS). and temperature (°C) were recorded periodically.
Bedrock well development ceased after a minimum of 2 hours the wells
yielded relatively sediment free water, and exhibited consistent of pH,
specific conductance, and temperature measurements. Development
water was containerized and managed in accordance with the FSP
Appendix FSP-A.
4.02.3 Hydraulic Conductivity Testing
Methods
In situ hydraulic conductivity tests were performed on the newly installed
overburden and bedrock wells to estimate the horizontal hydraulic conductivity
in the overburden and bedrock materials in accordance with procedures
presented in FSP Appendix FSP-I. The tests were conducted by first inserting
a pressure transducer (AquiStar DL4A-16A, Instrumentation Northwest, Inc.)
into the well and then performing a rising head and/or a falling head hydraulic
conductivity test by inserting a solid PVC rod into the well. The transducer
system was used to collect recovery data at pre-programmed time intervals at all
newly installed monitoring wells except MW-113I, 113D, 115B, and 116B.
Hydraulic conductivity data were collected at these wells by hand using an
electronic water level probe, due to the protracted recovery times in these wells.
The slug test data collected from the overburden wells was interpreted
using the Bouwer and Rice method (Bouwer, 1989) for unconfined aquifers.
The slug test data collected from the bedrock wells was reduced using the
Cooper method (Cooper and others 1967). Both methods are contained in the
DRAFT 90 April 29, 1993
AQTESOLV™ Aquifer Test Solver program which is a computer program
designed for the reduction of in situ hydraulic conductivity tests Version 10
Documentation (Geraghty and Miller, Inc., 1988, 1989). Results of the
hydraulic conductivity test results are included on Table 4, and field pressure
transducer data and AQTESOLV plots are contained in Appendix E.
Results
Hydraulic conductivity data for each well is listed in Table 4 and
summarized as follows:
Hydraulic Conductivities
Overburden
l . l x l O ' 1 ft/day (MW-101S) to 7.46 ft/day (MW-111S)
Shallow Bedrock
3.3 x 10° ft/day (MW-118B) to 34.87 ft/day (MW-111B)
Intermediate Bedrock
1.62 X 10° ft/day (MW-113I) to 43.06 ft/day (MW-111I)
Deep Bedrock
2.01 x 10° ft/day
Hydraulic conductivity tests could not be performed on MW-101D.
Water between the 6-inch steel protective casing and the 2-inch PVC well casing
had frozen, thus causing the 2-inch PVC casing to buckle in a manner as not to
allow slugs or bailers to be inserted into the well. The permanence of this
damage will be assessed during the second round of ground water sampling, and
the well will be repaired as necessary.
DRAFT 91 April 29, 1993
4.02.4 Packer Testing
Packer tests were conducted in the bedrock boreholes at monitoring wells
MW-101D, 1041, 1061, 1101. 1111, and 113D as part of the Phase 1A Site
Characterization to evaluate flow in the fractured bedrock at the landfill site as
it relates to the potential for contaminant migration. In addition, packer tests
were performed to assist in evaluating the screened intervals for the shallower
bedrock monitoring wells at those locations.
Methods
Following the completion of the bedrock borehole, each borehole was
flushed with clean water to remove cuttings, and the depth of each borehole was
measured to check for borehole wall collapse. The packer testing equipment
(consisting of two inflatable rubber packers separated by a 2-inch diameter
perforated pipe) was lowered into the borehole. Upon reaching the interval to
be tested, the packers were inflated to approximately 500 psi through a high
pressure hose attached to a cylinder of compressed nitrogen. To monitor the
effectiveness of the seal, an in-line pressure gauge was utilized to monitor the
packer inflation pressure. Figure 19 shows a schematic of the packer testing
equipment. In addition, an appropriate seal of the test interval was confirmed
when the pressure in the inflated packers supported the weight of the entire
packer string.
Once the packer equipment was set within a borehole, a small diameter
submersible (Redi-Flo 2) pump was lowered to the bottom of the packer string
. and the interval was purged. Water level measurements were monitored above
the packed interval to check for potential leakage into the packed interval. If
DRAFT 92 April 29, 1993
a minimum 0.1 gpm continuous flow rate could be achieved during the purging
process, this flow rate was noted and a minimum of one test interval volume
was removed from the packed interval. When continuous flow rates could not
be maintained, due to the interval being pumped dry, the water level in the
packed interval was allowed to recover for 15 minutes. After the 15-minute
recovery period, the interval was purged again and the volume of water
recovered was measured. An estimated flow rate was calculated from the test
interval by dividing the volume of water recovered by the 15-minute recovery
period.
If a continuous or estimated flow rate of the test interval was greater than
0.1 gpm. then the test interval was sampled for VOC headspace analysis using
either a stainless steel bailer or pump at a flow rate less than 100 ml/min.
Samples were collected in 40-ml glass vials and analyzed using an on-site gas
chromatograph (GC) as discussed in Section 4.02.5. If the flow was calculated
to be less than 0.1 gpm, the test interval was not sampled, the packers were
deflated, and a new interval was tested. A summary of each packer tested
interval, with respect to estimated flow rates and VOC headspace analysis, is
included in Table 10.
DRAFT 93 April 29, 1993
4.02.4.1 Field Modifications
• Water levels within the packer string could not be monitored due
to the pump discharge hose and nitrogen supply lines preventing
the insertion of a water level probe within the 2-inch diameter
packer pipe.
• Subsequent to purging, the water levels in the packer string were
not monitored due to the pump continually getting caught on the
packer string couplings. By the time the pump was removed the
water level had recovered.
Due to the highly fractured nature of the bedrock in the vicinity
of the Barkhamsted Site, water levels above the packer string
during purging were often observed dropping, indicating leakage
into the packed interval through interconnected fractures. The
leakage was estimated by converting feet of observed drawdown
above the packer string to volume of water (gallons). This
leakage volume was subtracted from the total volume pumped
from the packed interval. The resulting difference was divided by
the time required to pump the packed interval, which gives an
approximate flow rate of the packed interval. The intervals which
exhibited leakage are noted in Table 10.
• VOC headspace samples were collected from the pump discharge
hose during packer testing of MW-101D intervals 219 ft to 229
ft, 209 ft to 219 ft, and 199 ft to 209 ft at a flow greater than 100
DRAFT 94 April 29, 1993
ml/min. After subsequent discussions with USEPA oversight
contractor personnel, the 100 ml/min standard was adopted.
• Initially, packer testing was initiated in 25-foot increments (MW
113D) in accordance with the FSP protocol. Subsequent packer
tests were performed in 10-foot intervals (MW-101D, MW-106I)
to more accurately define discrete flow zones. However, due to
the high incidence of packer leakage, packer testing was
performed at20-ft intervals (MW-104I, MW-1101, and MW-1 111)
to allow for timely installation of monitoring wells.
4.02.5 Packer Testing/Headspace Analysis
The objective of the packer test headspace screening was to evaluate
VOC concentrations at discrete depth intervals in order to select the optimal
screen interval for the bedrock wells. This objective was pursued by collecting
a series of ground water samples from packer tested intervals in six on-site
monitoring wells, and analyzing the headspace using a Photovac 10S70 portable
gas chromatograph (GC).
Ground Water Sample Collection
Ground water headspace samples were collected from packer tested
intervals using either a stainless steel bailer or from the pump discharge hose as
discussed in Section 4.02.4. The samples were then transferred to two 40 ml
vials equipped with teflon septa, headspace free, placed on ice, and transported
to the field laboratory. The two 40 ml vials were placed in a constant
DRAFT 95 April 29, 1993
temperature bath at 40° Celsius for 15 minutes. A syringe needle was placed
through the septa of one vial to act as a vent while 10 ml of the water sample
was removed by a 10 ml glass syringe. The vial was shaken thoroughly for 1
minute, and the sample was allowed to reach thermal and phase equilibrium by
standing in the constant temperature bath for an additional 10 minutes. A
precise 100 /x aliquot of headspace was then extracted from the vial using a gas-
tight syringe and injected into the Photovac GC. The second vial served as a
duplicate should re-analysis be required.
Results
A total of 24 ground water samples were collected for GC headspace
analysis from the packer tested intervals of six monitoring wells (MW-101D,
MW-104I, MW-106I, MW-110I, MW-111I, and MW-113D) and are
summarized in Table 10. Total VOC concentrations 'in monitoring well
headspace samples ranged from non-detect (<0.025 ppm) to 20.6 ppm. The
predominant calibrant compound detected in the ground water headspace
samples was toluene. Other calibrant compounds detected included vinyl
chloride (one sample), MEK (one sample), benzene, MIBK, toluene, and xylene.
Discussion of Packer Testing Results
The objective of packer testing was to evaluate flow in the fractured
bedrock at the landfill site as it relates to the potential for contaminant
migration. This objective was not fully achieved due to the highly fractured
nature of bedrock in the vicinity of the Barkhamsted Site, which resulted in
DRAFT 96 April 29, 1993
routine leakage of ground water into packer tested intervals. This leakage
compromised the integrity of ground water headspace samples and did not allow
for precise measurement of flow rates within a packer tested interval. It is
concluded that the headspace analysis is not an appropriate technique for
evaluating potential contaminant migration at this site.
Packer testing was useful in evaluating relative flow rates within the
borehole. Despite the routine leakage into a packer tested interval, the leakage
was quantified, so as to evaluate which packer tested zone yielded the highest
flow rate. Subsequently, screened intervals could be selected to be consistent
with higher flow zones. However, flow rates can also be estimated using yield
tests while drilling a monitoring well, which would reduce costs and time delays
for well installation.
4.03 Physical Characteristics of the Site
4.03.1 Regional Geology
The landfill study area is located in the southwestern portion of the New
Hartford, Northwestern Connecticut quadrangle (Figure 1). The surficial and
bedrock geology has been mapped by Schnabel (1973, 1975). Unconsolidated
deposits cover approximately 95 percent of the New Hartford quadrangle with
thicknesses ranging from 0 to 90 feet (Schnabel, 1975). The greatest volume of
the Pleistocene and Holocene surficial materials are composed of glacial
deposits, with lesser quantities of stratified drift, stream terrace deposits, swamp
deposits, and alluvium. Two types of glacial contact deposits are present locally
(Schnabel. 1975). A compact silt and clay matrix lodgement till was deposited
DRAFT 97 April 29, 1993
on the bedrock surface during glacial advance. The lodgement till is overlain
by a less dense, silt to boulder matrix which was deposited during glacial retreat.
Bedrock in the vicinity of the site is mapped as the Moretown Formation
(Middle Ordovician) consisting of fine-grained medium to medium-light-gray
quartz-plagioclase-biotite-(muscovite)-(garnet) schist containing thin beds of
fine-grained light green and black hornblende-epidote-plagioclase amphibolite
(Schnabel, 1975). Bedrock is not exposed at the site, however, a large bedrock
outcrop ridge runs in a north-south direction along the western side of the
Unnamed Brook.
Surficial Site Geology
Site geology has been interpreted based on samples collected from soil
borings, overburden monitoring wells and bedrock monitoring wells, as well as
available published literature. Geologic logs containing specific sample depths
and descriptions are contained in Appendix D.
During implementation of the Phase 1A RI, four surficial units,
consisting of fill material, glacial outwash and/or fluvial deposits, ice contact
deposits, and lodgement till were encountered within the landfill study area.
Figure 14 is a cross-section index map. Figures 15 and 16 are geologic cross-
sections illustrating the surficial geology in potential disposal Area A (A-A') and
Areas B and C (B-B'), respectively. The description and extent of each
encountered surficial deposit are as follows:
• The fill material, as described from soil boring samples, is mainly
composed of landfill debris (metals, plastics, wood products, etc.) as
DRAFT 98 April 29, 1993
shown in geologic cross sections A-A1 (Figure 15) and B-B' (Figure 16).
The areal extent of fill material is limited to the landfill (Figure 17)
disposal area, as has been shown by a series of test pits excavated around
the landfill and discussed in Section 3.07.
• Glacial outwash and/or fluvial deposits consisting of stratified sands, silts
and gravel are concentrated along the Farmington River floodplain.
These deposits were encountered in MW-117S and MW-118S and range
in thickness from 10 ft to 63 ft, respectively.
• Poorly sorted, moderately dense to very dense sand, silt, cobble and
gravel ice contact deposits were encountered across the majority of the
site. This unit appears to thicken northward toward the Farmington
River valley as shown in geologic cross section C-C1 (Figure 20). The
ice contract deposits overlies bedrock at areas north and east of a line
connecting the MW-110, MW-1. and MW-106 well nests (Fuss &
O'Neill, 1991b).
A poorly sorted, dense, silt and clay matrix lodgement till was
encountered in soil samples in a limited area at the site. This till unit
was encountered at soil borings B-8 (Figure 15) through B-14 at depths
ranging from 8.5 feet at B-l 1 to 14 feet at B-8. It was also encountered
in MW-112B, MW-113S, and MW-107B at depths ranging from
approximately 10 feet at MW-107B to approximately 20 feet at MW
112B (Fuss & O'Neill, 1991). The lodgement till overlies the bedrock
in the southern portion of the site, extending northward to the MW-106
well nest (Figures 20 and 21). In addition, the lodgement till was
DRAFT 99 April 29, 1993
encountered beneath the fill in MW-119F, suggesting lodgement till
underlies the landfill disposal area (Figure 20). The northward extent of
the lodgement till unit appears to end at a line connecting the MW-110
and MW-1 nests where ice contact deposits were encountered overlying
bedrock (Fuss & O'Neill, 1991b).
4.03.2 Site Bedrock Geology
Fifteen bedrock monitoring wells were installed at the site at depths
varying from approximately 67 feet below ground surface at MW-113B to
approximately 250 feet below ground surface at MW-113D. The bedrock wells
were installed to screen the shallow, intermediate, and deep bedrock zones.
Depth to bedrock varied across the site from approximately 10 feet below
ground surface at MW-117B to approximately 63 feet below ground surface at
MW-118B.
Bedrock cuttings were collected and described at each drilling location.
Bedrock encountered at the Barkhamsted Site is a pegmatite intruded micaceous
schist. During drilling, the bedrock formation was described as soft to
moderately hard. The softness of the rock made distinctions between the
weathered and competent bedrock stratums not easily definable. In addition,
bedrock softness made identification of fracture zones difficult during drilling.
However, as indicated from packer testing results (Section 4.02.4), bedrock was
moderately to highly fractured.
Geologic cross section C-C? (Figure 20) is oriented from south of the
landfill disposal area across the site to the northeast to the MW-111 nest on the
DRAFT 100 April 29, 1993
Farmington River floodplain, as shown in Figure 14. As shown from the cross
section and the boring logs, weathered schist was more thick to the south of the
site and ranged from approximately 6 ft in MW-111 to 75 ft in MW-113. The
bedrock surface across the site dips to the north-northeast which is supported by
bedrock elevations estimated from resistivity surveys as shown in Figure 10.
4.03.3 Regional Hvdrogeologv
The Barkhamsted Site is situated along the west branch of the
Farmington River Basin. The Farmington River Basin is located in north central
Connecticut. The present regional topography is the result of Pleistocene Age
glaciation. In general, the regional ground water supply is located in overburden
deposits and the bedrock (Handman et al, 1986). However, bedrock ground
water was the predominant ground water supply in the vicinity of the
Barkhamsted Site as discussed in Section 4.05.
The overburden aquifer is comprised of either glacial contact deposits
(till), glacial outwash deposits (stratified drift), or alluvial and/or fluvial deposits.
The glacial contact deposits are divided into either ablation or lodgement t i l l .
These till units are relatively thin and are poor aquifers. Hand dug wells in the
vicinity of the Barkhamsted Site are typically screened within till units.
Glacial outwash deposits are sediments which have been transported and
deposited by glacial meltwater into interbedded gravel, sand, silt and clay
deposits. Alluvial and/or fluvial deposition is similar to glacial outwash deposits
and is an ongoing process today. Glacial outwash and alluvium fill the valleys
and lowlands, and covers approximately 22% of the Farmington River Basin
DRAFT 101 April 29, 1993
(Handman et al, 1986). Glacial outwash deposits are the most productive of
overburden aquifers averaging 100 ft in thickness in the Farmington River
Basin. The median yield from this overburden aquifer is 141 gpm with yields
ranging from 4 to 1400 gpm (Handman et al, 1986). However, results of the
ground water user survey (Section 4.05) indicate that ground water supply wells
in the vicinity of the Barkhamsted Site are not screened in this unit.
The bedrock which underlies the Farmington River Basin is a
metamorphic schist as discussed in Section 4.03.1. Bedrock ground water is a
source of water supply for home owners in the vicinity of the Barkhamsted Site.
Ground water storage and movement in bedrock generally occurs in fractures.
Well yields in the bedrock aquifer in the Farmington River Basin range from 0.1
to 200 gpm, with a median yield of 5 gpm (Handman et al, 1986).
4.03.4 Site Hydrogeologv
Two complete rounds of ground water and surface water elevations were
completed on December 28, 1992 and January 26, 1993 as presented in Table
4. In addition, stream water gauge readings are included in Table 11. Ground
water elevations recorded from the latter round are discussed in this section.
An estimation of ground water transmitting capacity is presented for each
water bearing zone. A range of linear ground water flow velocities can be
approximated using the following equation:
DRAFT . 102 April 29, 1993
Darcv's Law
V=Ki/n
Where:
v = velocity (ft/day)
K = hydraulic conductivity (ft/day)
i = hydraulic gradient (ft/ft)
n = average porosity
The following assumptions were made in applying Darcy's Law:
• The average porosity for the overburden (clay to gravel) is 30%
(Todd, 1980) and porosity for the bedrock was derived from the
apparent porosity log which was performed on the monitoring
well MW-4R-1+2 borehole as described in the LFI Summary
Report. The apparent porosities with respect to elevation were
assumed to be constant across the site. Table 12 lists screened
elevations and porosities for that elevation encountered in V1W
4R-1+2.
• Bedrock behaves as a porous media due to its moderate to highly
fractured nature.
Overburden Zone
Depth to water in the overburden wells varied from 3 ft at S-3 to 18.9
ft at MW-105S. A ground water elevation map (Figure 22) was constructed for
the overburden ground water flow from data collected on January 26, 1993.
Ground water flow in the overburden is to the north in the vicinity of the
landfill disposal area. The overburden ground water flow is diverted to the
DRAFT 103 April 29, 1993
northeast adjacent to the Unnamed Brook and flows off the RRDD#1 property,
north of the landfill disposal area. Ground water within the overburden flows
under hydraulic gradients ranging from 0.009 ft/ft to 0.16 ft/ft and with an
appropriate velocity of 3.1x10"2 ft/day to 2.36 x 10"' ft/day.
Shallow Bedrock Zone
Depth to water in the shallow bedrock wells varied from 1.35 ft at MW
5B to 35.02 ft at MW-115B. A ground water elevation map (Figure 23) was
constructed for the shallow bedrock ground water flow from data collected on
January 26, 1993. Ground water flow in the shallow bedrock in the vicinity of
the landfill disposal area is to the north. Similar to overburden flow, bedrock
ground water flow diverts to the northeast as it flows from RRDD#1 property.
Shallow bedrock ground water flows under hydraulic gradients ranging from
0.008 ft/ft to 0.20 ft/ft and with an approximate velocity of 2.21 x 10° ft'day to
13.99 ft/day.
Intermediate Bedrock Zone
Depth to water in the intermediate bedrock wells varied from 1.94 feet
at MW-110I to 18.88 feet at MW-4R-2. A ground water elevation map (Figure
24) was developed from the intermediate bedrock ground water flow from data
collected on January 26, 1993. Ground water flow in the intermediate bedrock
is to the north-northeast under hydraulic gradients ranging from 0.032 ft/ft to
0.12 ft/ft. The approximate ground water velocity from the intermediate bedrock
depths range from 1.56 x 10° ft/day to 43.06 ft/day.
DRAFT 104 April 29, 1993
Deep Bedrock Zone
Depth to water in the deep bedrock wells varied from approximately 2
feet above ground surface at MW-113D to 18.62 feet at MW-4R-1. A ground
water elevation map (Figure 25) was constructed for the deep bedrock ground
water flow from data collected on January 26, 1993. Ground water flow in the
deep bedrock is to the north under a relatively uniform hydraulic gradient of
approximately 0.085 ft/ft. The estimated ground water velocity in the deep
bedrock zone is 3.42 x 10° ft/day.
4.03.5 Conceptual Site Hvdrogeologic Model
The conceptual hydrogeologic model for the Barkhamsted Site was
developed based upon the evaluation of packer tests, hydraulic conductivity
tests, vertical gradients, and ground water elevations. Figures 26 and 27 present
semi quantitative flow nets which illustrate the hydraulic relationship between
the various geologic zones and surface water bodies at the Barkhamsted Site.
Cross section E-E' (Figure 26) shows the hydrogeologic conditions from
the vicinity of the landfill disposal area across the Unnamed Brook, north of the
RRDD#1 property line to MW-104 well nest (Figure 14). Vertical gradient data
are presented in Table 13. As indicated in Figure 26, the overburden and
bedrock aquifer systems act as an interconnected hydraulic unit. Downward
vertical gradients ranging from 0.005 ft/ft to 1.68 ft/ft exist between the
overburden and bedrock in the vicinity and south of the landfill disposal area.
The highest downward vertical gradient exists in the MW-110 nest, located
DRAFT 105 April 29, 1993
along the northern toe of the landfill disposal area. This suggests contaminated
ground water may move downward as well as northward in this vicinity.
Overburden to bedrock vertical gradients north of the landfill disposal
area are upward ranging from 0.016 ft/ft to 0.083 ft/ft. These data suggest that
ground water flows upward as it flows toward the Unnamed Brook north of the
site. Ground water elevation and vertical gradient data indicate that the
overburden is hydraulically connected to the Unnamed Brook (Figure 26).
Although ground water within the bedrock zones has an upward potential north
of the landfill disposal area, flow from the deeper zones may not be
hydraulically connected to the Unnamed Brook (Figure 26).
As indicated from the ground water elevation maps, ground water flow
converges and is diverted to the northeast in the vicinity of the Unnamed Brook
north of the landfill. This ground water diversion is caused by the topographic
high which exists northwest of the site (Figure 1). This is further evidenced by
the ground water quality data in MW-104 nest which indicates that the
contaminant plume does extend to this location. Although bedrock ground water
may not be hydraulically connected to the Unnamed Brook north of the landfill.
the diversion of ground water flow to the northeast indicates contaminants from
the Barkhamsted Site do not extend beyond the Unnamed Brook in this vicinity.
Cross section F-F' (Figure 27) shows the hydrogeologic conditions in the
vicinity of the landfill disposal area, across the site, to the northeast in the
direction of ground water flow (Figure 14). Overburden to bedrock vertical
gradients are upward to the northeast of RRDD#1 property ranging from 0.002
ft/ft to 0.082 ft/ft (Table 13). As shown in Figure 27, flow paths from the
DRAFT 106 April 29, 1993
overburden and shallow to deep bedrock zones are upward toward the
Farmington River Floodplain indicating that the floodplain is a local ground
water discharge area. Based on the data, contaminated ground water movement
from the Barkhamsted Site will eventually flow to the floodplain.
4.04 Ground Water Sampling
Ground water samples were collected from December 28, 1992 through January
6, 1993 from all site monitoring wells to characterize and quantify the contaminants
within the various water bearing zones.
4.04.1 Methods
Ground water samples were collected in accordance with the procedures
specified in the FSP (Appendix FSP-J). Prior to ground water sampling, a
complete round of static ground water elevations was collected from the site
monitoring wells. Based upon historical ground water quality data, monitoring
wells were sampled in an order from suspected least contaminated to most
contaminated. Ground water sampling equipment was decontaminated in
accordance with procedures included in the FSP (Appendix FSP-D). In addition.
subsequent to well purging, purge water was handled in accordance with
procedures included in FSP Appendix FSP-A. Ground water field sampling logs
are contained in Appendix F.
Each ground water sample was shipped to Pace Laboratories, Inc. in
Wappingers Falls, New York using approved chain of custody procedures.
Samples were analyzed for the TCL/TAL parameters listed in Table 5.
Analytical results for volatiles, semivolatiles, pesticides/PCBs and metals are
DRAFT 107 April 29, 1993
summarized in Tables 14A through 14Ds, respectively. A discussion of
monitoring well sample results is presented below.
4.04.2 Results
Background Ground Water Quality Conditions
Monitoring well nests MW-112, MW-113, MW-114, MW-115, and MW
116 are located to the south, west, and east of the landfill disposal area as shown
in Figure 18. These well nests were located to assess the ground water quality
upgradient and adjacent to the landfill disposal area relative to ground water
flow across the site. Results of the TAL/TCL analysis from this area is discussed
below:
• Results of the TCL volatile analysis are discussed as follows:
VOCs were not detected in the MW-112, MW-114, MW-115, or
MW-116 well nests. In addition, VOCs were not detected in
MW-113S.
Monitoring wells MW-113B, MW-1131, and MW-113D detected
toluene at 2 jzg/L , 3 /xg/L, and 16 fig/L. respectively.
• Semivolatile results are discussed as follows:
Bis(2-Ethylhexyl)phthalate was detected in the MW-112 nest, and
in MW-113S, B, & I, the MW-114 nest, MW-115B, and the
MW-116 nest at estimated concentrations below the quantitation
limit.
DRAFT 108 April 29, 1993
Di-n-butylphthalate was detected in the MW-112 nest, MW-113S,
and MW-114S at estimated concentrations below the quantitation
limit.
The compound 4-nitroaniline was detected in MW-1131 at an
estimated concentration below the quantitation limit.
The compound N-nitrosodipheylamine and 3-nitroaniline were
detected in MW-115B at estimated concentrations below the
quantitation limit.
• PCB/pesticides were not detected upgradient or adjacent of the landfill
disposal area.
• A discussion of the background metal concentrations is as follows:
Monitoring well MW-113S detected beryllium (2.8 /ig/L),
chromium (143 ng/L), and antimony (25.4 /zg/L) at concentrations
above the federal MCLs for drinking water.
Monitoring well MW-114S detected antimony (32.3 /zg/L).
beryllium (3.1 ng/L), chromium (197 /ig/L), and nickel (155
/xg/L) at concentrations exceeding the federal MCLs for drinking
water.
Monitoring well MW-116S detected antimony (33.9 ^ig/L),
beryllium (4.2 /ng/L), chromium (266 /ng/L), and nickel (137
/ig/L) at concentrations above the federal MCLs for drinking
water.
Beryllium concentrations were greater than the federal MCL in
MW-115S (2.6 /xg/L) and MW-116B (1.5 /xg/L)
DRAFT 109 April 29, 1993
The chromium concentration in MW-115S was 106 /xg/L, which
exceeds the federal MCL.
The results of TCL analysis upgradient and adjacent to the landfill
disposal area indicate that the ground water in areas encompassed by monitoring
well nests MW-112, MW-113, MW-114, MW-115, and MW-116 has not been
impacted by the landfill disposal area. Based on these results, the analytical
data from these wells will be used to represent background ground water quality
at the Barkhamsted Site.
The TAL metal analytical data from the wells have been utilized to
assess ground water quality downgradient (north) of the landfill disposal area.
Downgradient overburden concentrations are evaluated in relation to MW-112S
and MW-113S, and shallow bedrock concentrations are evaluated in relation to
MW-112B and MW-113B. The intermediate and deep bedrock metal
concentrations are evaluated in relation to the background range established in
MW-113I and MW-113D.
The most widespread migration of site-related compounds in ground
water at the Barkhamsted Site is best characterized by the extent of VOCs and
semivolatiles. A comparison of VOC concentrations and semivolatile
concentrations indicates that total concentrations are similar in the vicinity of the
landfill disposal area; however, VOC concentrations exceed semivolatile
concentrations downgradient. Therefore VOC concentrations were utilized to
discuss the extent of the contaminant plume at the Barkhamsted Site.
Figures 28, 29, 30, and 31 depict the VOC plumes in the overburden,
shallow bedrock, intermediate bedrock, and deep bedrock water bearing zones,
DRAFT 110 April 29, 1993
respectively. As indicated from the figures and discussed above, the
background well nests contain trace levels of VOCs in the shallow, intermediate
and deep bedrock water bearing zones. Well nests MW-113, MW-114, MW-115
and MW-116 define the contaminant plume at their respective locations on site.
North of the Landfill Disposal Area
The following is a discussion of the ground water quality north of the
landfill disposal area. The area north (downgradient) of the landfill is structured
into discussion of each aquifer zone (overburden; shallow, intermediate and deep
bedrock zones).
Overburden Zone
The overburden VOC contaminant plume is centered in the vicinity of
MW-1S as shown in Figure 28. The overburden plume is oriented in a north
to south direction around well MW-101S to the north and MW-110S to the
south. VOCs were not detected in MW-104S, MW-105S, and MW-113S
(Figure 28). The Unnamed Brook defines the northern extent of the overburden
plume and MW-113S defines the southern extent on the RRDD#1 property. As
discussed above, the western boundary does not extend beyond MW-107S and
MW-114S, and the eastern boundary does not extend beyond MW-115S and
MW-116S.
The overburden VOC plume migrates off the RRDD#1 property to the
northeast. As the plume extends off-site, the Unnamed Brook defines the
northwestern boundary, and MW-102S, MW-103S and MW-1088 define the
southeastern boundary. The downgradient extent of the plume is defined by
DRAFT 111 April 29, 1993
MW-111S which is located along the Unnamed Brook on the Farmington River
floodplain.
The overburden contaminant plume contains VOCs, semivolatiles and
metals as discussed below:
• VOCs detected within the overburden plume consist primarily of acetone,
2-butanone, toluene, methylene chloride, and 4-methyl-2-pentanone.
Acetone concentrations within the plume ranged from 38 jig/L in
S-3 to 13,000 Mg/L in MW-1S.
Concentrations of 2-butanone ranged from 30 /xg/L in S-3 to
30,000 pg/L in MW-1S.
Toluene concentrations ranged from 200 /ig/L MW-5S to 7600
/xg/L in MW-11 OS.
Methylene chloride concentrations ranged from 320 /xg/L in MW
1S to 970 ng/L in MW-101S
Concentrations of 4-methyl-2-pentanone ranged from 16 /zg/L in
S-3 to 1400 ng/L in MW-1S.
Other VOCs were detected in the overburden contaminant plume and
included benzene, chloroethane, ethylbenzene, 1,2-dichloroethene, trichloro
ethene, 1,1-dichloroethane, 1,2-dichloroethane, and 2-hexanone.
• The semivolatile compounds which were detected in the overburden
monitoring wells within the plume are discussed as follows:
Concentrations of bis(2-ethylhexyl)phthalate ranged from 0.5/xg/L
in MW-110S to 10,000 /ig/L in MW-101S.
DRAFT 112 April 29, 1993
Concentrations of 2, 4-dimethylphenol ranged from 3 /xg/L in
MW-110S to 3100 fig/L in MW-101S.
Concentrations of 4-methylphenol ranged from 62 /xg/L in MW
110S to 45,000 /xg/L in MW-1S.
Concentrations of 2-methylpheriol ranged from 6 jig/L in S-3 to
2600 /zg/L in MW-101S.
Concentrations of phenol ranged from 14 /xg/L in MW-4S to 5600
/ig/L in MW-101S
Semivolatiles were detected in downgradient wells MW-104S and MW
105S. However, concentrations were below the quantitation limits.
Semivolatiles were not detected in the overburden monitoring wells east of
Route 44.
• PCBs/pesticides were not detected in the overburden monitoring wells
above the quantitation limit.
• Overburden metal concentrations were evaluated in relation to the
background range established in wells MW-112S and MW-113S. The
following is a discussion of overburden metal concentrations:
The highest metal concentrations on the RRDD#1 property were
detected within the axis of the overburden plume as defined by
wells MW-101S, MW-1S, and MW-110S (Figure 28). Within
this plume, the most elevated metal concentrations were observed
in MW-1S and ranged from two times background (zinc) to 106
times background (sodium). Overburden ground water metal
constituents which exceeded the federal drinking water MCLs in
DRAFT 113 April 29, 1993
MW-1S included barium at 4830 /xg/L, nickel at 139 /xg/L, and
antimony at 120 /xg/L.
The metal component of the overburden contaminant plume
extends to MW-4S and MW-5S where the most elevated metal
concentration (sodium) is 11 times background in both wells.
Antimony concentrations in MW-4S (14.8 /zg/L) and MW-5S
(30.8 /xg/L) were greater than the federal MCL. In addition,
nickel at 112 /xg/L was greater than the MCL in MW-4S.
Although elevated metal concentrations are observed
downgradient of the RRDD#1 property, in general these
concentrations are approximately two times the background
values. Exceptions to this include metal concentrations in MW
105S where sodium is 81 times the background concentration,
and MW-111S where elevated metals range from less than two
times background (thallium) to 17 times background (sodium).
Metal concentrations which exceed federal MCLs in MW-111S
includes beryllium at 9.8 /xg/L, antimony at 25.1 /xg/L. chromium
at 443 /xg/L, and nickel at 375 /xg/L.
Mercury was detected in S-3 and MW-11 IS at 2.0 /xg/L and 0.27
/xg/L. The concentrations are at and below the federal drinking
water MCL of 2 /xg/L.
Shallow Bedrock Water Bearing Zone
The shallow bedrock VOC contaminant plume is centered in the vicinity
of MW-110B to the south, MW-101B to the north, and MW-4R to the northwest
DRAFT 114 April 29. 1993
as shown in Figure 29. Similar to the overburden plume, the Unnamed Brook
defines the northern extent of the shallow bedrock contaminant plume. MW
113B defines the southern extent of the plume on the RRDD#1 property. The
western plume boundary does not extend as far as MW-107B and MW-114B,
and the eastern boundary does not extend as far as MW-115B and MW-116B.
The shallow bedrock plume extends off the RRDD#1 property to the northeast.
In this direction, the Unnamed Brook defines the northwestern boundary and MW
102B, MW-103B, and MW-108B define the southeastern boundary. The downgradient
extent of the plume extends beyond MW-11 IB, but not as far as MW-118B.
The shallow bedrock water bearing zone contaminant plume consists of
VOCs, semivolatiles, and metals as discussed below:
• Most of the VOCs which constitute the shallow bedrock plume include
acetone, butanone, toluene, and 4-methyl-2-pentanone as discussed
below:
Acetone concentrations within the plume ranged from 26 pg/L in
MW-1R to 2,000 jtg/L in MW-101B.
Concentrations of 2-butanone ranged from 33 /xg/L in MW-1R to
7,000 pg/L in MW-101B.
Toluene concentrations ranged from 9 j*g/L MW-5B to 11,000
/xg/L in MW-11 OB.
Concentrations of 4-methyl-2-pentanone ranged from 16 /xg/L in
MW-5B to 390 /xg/L in MW-101B.
DRAFT 115 April 29, 1993
Other VOCs detected in the shallow bedrock contaminant plume included
ethylbenzene, 1,2-dichloroethane, 1.1 -dichloroethane, benzene, xylenes,
trichloroethene and 1,2-dichloroethene.
• The semivolatile compounds which constitute the shallow bedrock
contaminant plume are discussed as follows:
Bis(2-Ethylhexyl)phthalate was detected at concentrations ranging
from 0.6 Mg/L in MW-105B, MW-108B, and MW-111B to 430
Mg/L in MW-101B.
Concentrations of 2,4-dimethylphenol ranged from 16 /xg/L in
MW-5B to 830 Mg/L in MW-101B.
Concentrations of 4-methylphenol ranged from 0.6 ^g/L in MW
108B to 11,000 Mg/L in MW-101B.
Concentrations of 2-methylphenol ranged from 24 /ig/L in MW
1R to 760 ^g/L in MW-101B.
Phenol Concentrations ranged from 16 ^g/L in MW-l 10B to 1700
/ig/L in MW-101B.
SVOCs were detected in downgradient wells MW-103B, MW-105B.
MW-108B, MW-111B, MW-117B, and MW-118B. However, the downgradient
SVOC concentrations are all below the quantitation limits.
• Heptaclor epoxide was detected at an estimated concentration of 0.03
ug/L in MW-103B. PCB/Pesticides were not detected in any other
shallow bedrock monitoring wells.
• Shallow bedrock metal concentrations were evaluated in relation to the
background range established in wells MW-112B and MW-113B. The
DRAFT 116 April 29, 1993
following is a discussion of metal concentrations in the shallow bedrock
zone:
The most elevated metal concentrations were detected within the
axis of the shallow bedrock plume as defined by wells MW-101B
and MW-110B (Figure 29). Within this plume, the most elevated
metal concentrations were observed in MW-101B and ranged
from three times background (antimony, arsenic & silver) to 155
times background (iron). The following metal concentrations
exceeded federal MCLs in MW-101B: antimony at 52.5 jig/L,
barium at 2170 ^ig/L, beryllium at 13.5 jig/L, chromium at 466
/xg/L, and nickel at 449 ng/L.
Similar to the trends observed in the overburden plume, elevated
metal concentrations in the shallow bedrock zone have been
detected downgradient of the RRDD#1 property. These
concentrations are approximately two to five times background
values. Exceptions to this include metal concentrations in MW
108B, where cobalt is six times the background concentration.
and MW-11 IB where sodium is 19 times background.
Mercury was detected in MW-102B and MW-103B at 0.75 /xg/L
and 1.2 figfL, respectively. Both concentrations are below the
federal MCL of 2.0 /*g/L.
Intermediate Bedrock Water Bearing Zone
The intermediate bedrock VOC contaminant plume is centered in the
vicinity of MW-101I as shown in Figure 30. The plume extends from MW-1011
DRAFT 117 April 29, 1993
to the northeast beyond MW-11II. MW-1131 exhibited 3 /xg/L of toluene and
defines the southern extent of the intermediate bedrock VOC contaminant plume
on the RRDD#1 property.
The intermediate bedrock water bearing zone contaminant plume consists
of VOCs, semivolatiles and metals as discussed below:
• The primary VOC constituents of the intermediate bedrock plume are
acetone, 2-butanone, toluene, 1,1 -dichloroethane, and 1,2-dichloroethene
as discussed below:
Acetone was detected in MW-1011 at 270 /ig/L.
Concentrations of 2-butanone ranged from 15 /xg/L in MW-4R-2
to 680 jug/L in MW-101I.
Toluene concentrations ranged from 2 jzg/L in MW-1101 to 29
Mg/L in MW-101I.
1,1-dichloroethane. and 1,2-dichloroethene were detected in MW
1111 at 5 ng/L and 180 /ig/L, respectively.
Estimated trace quantities of trichloroethene were detected in
MW-1061 and MW-4R-2.
• The total SVOC concentrations in the intermediate bedrock wells within
the plume ranged from 1.0 Mg/L in MW-1 111 to 258 /zg/L in MW-1011.
The primary SVOCs detected in MW-101I were 2,4- dimethyl-
phenol, 4-methylphenol, 2-methylphenol, diethylphthalate, and
phenol.
• PCB/pesticides were not detected in the intermediate bedrock zone.
DRAFT 118 April 29, 1993
• Intermediate bedrock metal concentrations were evaluated in relation to
the background values established between MW-113I and MW-1131).
The following is a discussion of metal concentrations in the intermediate
bedrock zone:
The most elevated metal concentrations detected in the
intermediate bedrock zone were manganese at 58 times
background in MW-101I, and magnesium at 73 times background
in MW-4R-2. Intermediate bedrock zone metal concentrations
did not exceed federal MCLs.
Elevated metal concentrations were detected downgradient in
MW-111I. These elevated concentrations ranged from less than
two times background (zinc) to 38 times background
(manganese). Downgradient intermediate zone metal
concentrations did not exceed federal MCLs.
Deep Bedrock Water Bearing Zone
The deep bedrock VOC contaminant plume is centered in the v i c imt \ of
MW-101D as shown in Figure 31. The plume extends from MW-101D to the
south to MW-113D. The eastern extent is defined by MW-4R-1 in which no
VOCs were detected.
The deep bedrock water bearing zone contaminant plume consists of
VOCs, SVOCs, and metals as discussed below:
• The volatile constituents which constitute the deep bedrock plume
include acetone, 2-butanone, and toluene.
DRAFT . 119 April 29, 1993
Acetone was detected in MW-101D at 35 /ig/L and in MW-113D
at 31 /ig/L.
2-butanone was detected in MW-101D at 84 ^tg/L.
Toluene concentrations ranged from 3 jug/L in MW-101D to 16
/tg/L in MW-113D.
• Semivolatile compounds were detected in MW-101D at 24.9 ppb.
• PCB/pesticides were not detected in the deep bedrock zone.
• Deep bedrock metal concentrations were evaluated in relation to the
background values established in MW-113D. The following is a
discussion of metal concentrations in the deep bedrock zone:
The most elevated metal concentrations were detected in MW-4R
1 and ranged from less than two times background to 256 times
background (manganese). Metal concentrations within the deep
bedrock zone did not exceed federal MCLs.
4.05 Ground Water Users Survey
\ ground water users survey was conducted to identify and locate residential,
commercial, municipal, and industrial ground water users within a 1 -mile radius of the
landfill. The area covered by the groundwater users survey is illustrated on Figure 32.
The objective of the ground water users survey was to assess potential impacts that the
landfill may have had on ground water users within a 1-mile radius of the Barkhamsted
Site. The ultimate goal of the ground water users survey was to develop a sufficient
data base to implement a domestic supply well sampling program, as described in
Section 4.06.
DRAFT 120 April 29, 1993
Methods
The primary method used to gather data on the ground water use within a 1-mile
radius of the Barkhamsted Site was a door-to-door survey. A Ground Water User
Survey Form was developed to obtain property owner information, water supply
information at each property (public water supply source vs. private well), and available
information on any private well on the property. This form was hand delivered to each
residence, business or other institution within a 1-mile radius of the Barkhamsted Site.
Included with the survey form was a letter explaining the purpose of the survey and a
stamped, self-addressed envelope for the convenience of the individual from whom
information was requested. A copy of the Ground Water Use Survey Form and the
accompanying letter is included in Appendix G.
Ground Water Use Survey Forms were hand-delivered to a total of 221
residences, businesses, and institutions (churches, etc.) in December 1992. Responses
were received from a total of 106 residences, 3 businesses, and 1 church for a total of
110 responses. The total percentage of survey response was approximately 50 percent.
The information obtained through the survey was supplemented with additional
information obtained through appropriate local and state agencies, including the
Farmington Valley Health District and the State of Connecticut Department of Health.
Computer data bases from the National Ground Water Association and the USGS were
reviewed, however, detailed information related specifically to ground water users
within a 1-mile radius of the Barkhamsted Site was not available. Results of the ground
water users survey, including data from all available sources, were tabulated and are
included in Appendix H.
DRAFT - 121 April 29, 1993
Results
Although specific information was not obtained from every ground water user
within a 1-mile radius of the site, sufficient information was obtained to conduct a
representative evaluation of the ground water use in the area and the potential impact
that the Barkhamsted Site may have had on the local ground water users.
The results of the ground water users survey indicate that, with the exception of
a small area within the Village of New Hartford, the residences, businesses and
institutions within a 1-mile radius of the Barkhamsted Site utilize ground water as the
primary water supply source. The New Hartford Water Company provides a public
water supply source for some residences within the Village of New Hartford that fall
within the southern most portion of the survey area, including parts of Main Street,
Highland Avenue, and Johnnycake Lane, as indicated on Figure 32.
The local ground water users obtain water supplies from multiple zones within
the overburden and bedrock aquifers. Water supply wells range in depth from shallow
hand-dug wells to 505 feet into the bedrock. The majority of the wells are installed
within the bedrock at depths greater than 100 feet. Well yields are typically less than
10 gallons per minute (gpm), with a few wells reporting yields up to 80 gpm.
The results of the ground water users survey were used to develop a domestic
supply .well sampling program as discussed in Section 4.06.
4.06 Domestic Supply Well Sampling
A domestic supply well sampling program was implemented to evaluate the
potential impacts to local homeowners from ground water contamination at the
Barkhamsted Site. The domestic supply wells to be sampled were selected based on
DRAFT 122 April 29, 1993
the Barkhamsted historical ground water flow direction in the bedrock aquifer,
proximity to the landfill, and data collected during the Fuss & O'Neill investigation.
4.06.1 Methods. Locations, and Analyses
Water samples were collected from ten domestic supply wells listed on
Table 15. Table 15 indicates the domestic well depths, if known, and the basis
for sampling selection. The domestic supply well locations are illustrated on
Figure 32.
Prior to sampling each of the domestic supply wells, information was
obtained from the owner as to whether a holding tank was part of their supply
system. All but one domestic supply well (the Eddy residence) was verified as
having a holding tank as part of their water supply system. Domestic supply
well samples were collected at the kitchen faucets of all residents except at the
DMR Landscaping/Accurate Welding property, the Eddy property, and the
Baumann property which were collected from outside faucets. Prior to sample
collection at each property, the water was allowed to flow for approximately
one-half hour to drain the holding tank and/or remove stagnant water from the
system. Well evacuation and sampling procedures were followed in accordance
with the protocols outlined in Appendix FSP-K. of the FSP.
Domestic supply well samples were collected on January 25, 1993. The
samples were analyzed for the TCL/TAL parameters specified on Table 5 using
USEPA drinking water analytical methods. QA/QC samples were collected in
accordance with the procedures identified in the QAPP contained in the RI
DRAFT 123 . April 29, 1993
Work Plan. After sampling was completed at each property, pH, conductivity,
and temperature measurements were recorded and are presented below:
Sampling Point Location pH Conductivity (/xS) Temperature (C°)
Case Residence 10.0 80 9
Jones/Murray Residence 9.9 60 10
Yahne Residence 8.0 210 10
DMR Landscaping / Accurate 8.6 120 11 Welding Property
Young Residence 8.4 50 10
Eddy Residence 8.9 110 10
Swain Residence 8.0 110 11
Baumann Residence 8.1 110 9
Almori Residence 8.2 130 10
Scaramuzza Residence 8.0 50 11
Results of domestic supply well TCL volatile analysis are included on Table 16A.
VOCs were not detected in the domestic supply wells.
A review of Table 16B indicates that the diethylphthalate was detected at a
estimated concentration of below the quantitation limit in the DMR
Landscaping/Accurate Welding sample. No other SVOCs were detected in the domestic
supply well samples.
A review of Table 16C indicates that no PCB/Pesticides were detected in the
domestic supply well samples.
A review of Table 16D indicates that a total of 16 metals were detected in the
domestic supply well samples. Iron was detected in the Swain sample at a
concentration of 4.800 ug/'l, which exceeds the secondary MCL of 300 ppb. Lead was
detected in the Swain sample at a concentration of 29.2 ug/1 which exceeds the federal
DRAFT 124 April 29, 1993
action level of 15 ug/1. Antimony was detected in the Swain sample at a concentration
of 16.3 ug/1 which exceeds the federal MCL for antimony of 6 ug/1. It should be noted
that during sampling, the Swain residence expressed concern about potential lead
contamination from an abandoned railroad bed which borders their property to the west.
In addition, lead and antimony are common components of household plumbing (lead
based solder and supply lines) and their detection in the domestic supply well samples
is not considered to be site-related. None of the remaining domestic supply well
samples indicate concentrations of metals above the current federal MCLs for drinking
water.
DRAFT 125 April 29, 1993
SECTION 5 - AIR QUALITY ASSESSMENT
5.01 Introduction
This section presents the results of the air quality assessment performed at the
Barkhamsted Site during non-invasive and invasive activities on October 23, 1992,
October 27, 1992, November 16, 1992 and November 17, 1992. The air quality
assessment was performed in accordance with the FSP dated September 1992.
5.01.1 Objectives
The objective of the air quality assessment, as defined in the FSP, was
to collect data for use in evaluating whether site-related residues are being
transported from the site via air transport.
5.01.2 Scope Of Work
The scope of the air quality assessment, as defined in the FSP, was to:
• Collect environmental air samples at designated locations for volatile and
semivolatile compound analysis and compare the results to the
Occupational Safety and Health Administration (OSHA) Permissible
Exposure Limits (PELs) and the American Conference of Governmental
Industrial Hygienists (ACGIH) Threshold Limit Values (TLVs);
Measure respirable paniculate concentrations at the site and compare the
results to the OSHA PEL; and
DRAFT 126 April 29, 1993
• Measure the wind speed and direction, temperature, and atmospheric
pressure for use in selecting sampling locations, volume calculations, and
general data interpretation.
Consistent with the FSP, these activities were performed prior to and
during invasive RI activities. The results of the air sampling, in conjunction
with the measured meteorological parameters, will be used to evaluate the
potential transport of site-residues via the air pathway.
5.02 Methodologies
5.02.1 Schedule
Air quality sampling was performed on two occasions: during a period
when no invasive site activities were occurring (non-invasive) and during
monitoring well installation (invasive). The non-invasive air quality sampling
was performed on October 23, 1992 and October 27, 1992, while the invasive
air quality sampling was performed on November 16, 1992 and November 17.
1992.
5.02.2 Approach
Environmental air samples were collected during non-invasive activities
over 2 days for approximately 8 hours each day to establish baseline conditions.
In addition, environmental air samples were also collected during invasive
activities over 2 days for approximately 8 hours each day to simulate "worst
case" conditions. The criteria necessary to define "worst case" conditions were
based on the installation of monitoring wells near potential disposal areas, as
DRAFT 127 April 29, 1993
identified in the FSP. This condition was satisfied by collecting air samples
during the installation of wells at monitoring well nest MW-101. During the
LFI Well Inventory, MW-101-S had the highest recorded PID reading (6 ppm)
at the top of the casing of any of the inventoried wells.
A total of seven environmental air sampling stations were established at
the site. The locations of the stations are illustrated on Figure 33. These
locations were selected with the assistance the USEPA. A description of and
justification for selecting each sampling station location is presented below:
• AS-01 was established near monitoring well nest MW-101 to provide
data at a potential point source. Sampling during non-invasive activities
provided background data, while sampling during invasive activities
provided data at a potential point source during "worst case" conditions.
• AS-02 was established on the north-west side of the site near Seep 6 to
provide data during non-invasive and invasive activities.
• AS-03 was established in the center of the landfill disposal area to
provide data in relationship to the fill.
• AS-04 was established on the south side of the site to provide upwind or
downwind data, based on wind direction.
• AS-05 was established near Seep 9 to provide data at a potential point
source during non-invasive and invasive activities.
• AS-06 was established on an adjacent residence property located south
east of the site to provide data at a potential receptor location.
• AS-07 was established on an adjacent residence property located north
of the site to provide data at a potential receptor location.
DRAFT 128 April 29, 1993
Airborne paniculate monitoring was conducted at AS-01. This location
was selected to provide data regarding the emission of particulates at an invasive
activity. In addition to the air sampling stations, a meteorological station was
established at the site to provide data on the wind direction and speed,
temperature, and pressure. The meteorological data were used to identify
upwind and downwind sampling stations and to correct the air sampling volumes
for standard temperature and pressure (STP). The meteorological station was
located in the center of the landfill disposal area, adjacent to sampling station
AS-03.
5.02.3 Sampling and Analytical Methods
Volatile Compounds
Volatile organic air samples were collected on a carbon molecular sieve
(CMS) sampling device attached to a personal air sampling pump at the seven
sampling stations. The sampling pumps were pre-calibrated to a flowrate of
approximately 0.04 liters per minute (1pm) according to the FSP standard
operating procedure (SOP) for the collection of environmental air samples.
The air samples were collected continuously over a period of
approximately 8 hours at a height equivalent to the human breathing zone. A
field blank and duplicate samples were collected in accordance with the FSP.
The duplicate samples were collected within 12 inches of an existing
environmental air sampling station, at different locations each sampling day.
Following sample collection, the personal air sampling pumps were post-
calibrated as described in the SOP. The pre- and post-calibration data are
DRAFT 129 April 29, 1993
presented in Table 17. The average flowrate. average temperature/sampling day
and average barometric pressure/sampling day were inserted into the generalized
gas law to determine the total sampling volume for each sample.
At the end of each sampling day, collected samples were placed in a
laboratory-supplied airtight vessel and shipped via overnight mail to Pace
Laboratories, Golden, Colorado, in a cooler at a temperature of approximately
4°C. The samples and blank were analyzed by gas chromatography/mass
spectrometry (GC/MS), according to the US EPA method TO-2 and the
laboratory SOP developed for this method.
Semivolatile Compounds
Semivolatile organic air samples were collected at each sampling station
on a glass fiber filter followed by a sorbent tube containing 100 milligrams (mg)
of XAD-2 resin, with 50 mg of XAD-2 resin as a backup. The sampling media
were attached to a personal air sampling pump. The sampling pumps were pre
calibrated to a flowrate of between approximately 0.02 to 0.5 1pm according to
the SOP for the collection of environmental air samples.
The collection of a duplicate sample, sampling duration, and post-
calibration methods were the same as for the volatile samples.
The samples for each sampling day were wrapped in aluminum foil and
shipped via overnight mail to Pace Laboratories, Golden, Colorado, in a cooler
at a temperature of approximately 4°C. The samples and blank were analyzed
by GC/MS, following modified USEPA method TO-13 according to the
laboratory SOP developed for this method.
DRAFT 130 April 29, 1993
Airborne Respirable Particulate
Airborne respirable participate concentrations were measured at AS-01
using a Monitoring Instrument for the Environment (MIE) Real-Time Aerosol
Monitor (RAM-1) linked to a datalogger. The datalogger collected continuous
measurements from the RAM-1 including average concentrations.
Meteorological Data
On-site meteorological monitoring was conducted during the
environmental air monitoring program for the following parameters:
• Horizontal wind speed and direction
• Ambient temperature
• Atmospheric pressure
These parameters were measured continuously using a MET-1
meteorological station located in the approximate center of the landfill.
The predominant wind direction for the area is from the southwest
(Climates of the States. 1974). According to the FSP SOP, sampling was to be
postponed if the wind direction on the sampling date differed by more than 90°
as compared to the historical data.
5.03 Observations
Observations described in this subsection correspond to the sampling dates and
sampling stations. Sampling stations are shown on Figure 33.
DRAFT 131 April 29, 1993
5.03.1 October 23. 1992
The following observations were noted at the site on this date:
• No invasive activities related to the RI were being conducted.
• Material was being brought into the site for disposal during the sampling.
• The average temperature was 50°F and the average barometric pressure
was 1028 millibars according Northeast Regional Climate Center's
weather station located at Bradley International Airport (Bradley). In
addition, the wind was generally out of the south according to field
observations and meteorological data collected at Bradley. The wind
direction did not differ by more than 90° as compared to the historical
data.
The following table presents the orientation of the sampling stations with
respect to the wind direction, and pertinent observations that could influence the
interpretation of the air monitoring results:
Orientation to Landfill Sampling Observations - October 23, 1992
Upwind Downwind Station
AS-01 X Vehicles operating upwind of AS-01.
AS-02 X Also downwind of Seep 6.
AS-03 Located on landfill; vehicles operating upwind of AS-03.
AS-04 X
AS-05 X Downwind of Seep 9.
AS-06 X Residential receptor; vehicles operating upwind on Rte. 44.
AS-07 Residential receptor.
AS-08 Duplicate for AS-03.
DRAFT 132 April 29, 1993
5.03.2 October 27. 1992
The following observations were noted at the site on this date:
• No invasive activities related to the RI were being conducted.
• Material was being brought into the site for disposal during the sampling.
• The average temperature was 50°F and the average barometric pressure
was 1011 millibars according to the weather station located at Bradley.
In addition, the wind was generally out of the north-northwest according
to field observations and meteorological data collected at Bradley. The
wind direction differed by more than 90° as compared to the historical
data, as discussed in Section 5.04.
The following table presents the orientation of the sampling stations with
respect to the wind direction and pertinent observations that could influence the
interpretation of the air monitoring results:
Orientation to Landfill Sampling Observations - October 27. 1992
Upwind Downwind Station
AS-01 X
AS-02 X Downwind of Seep 6.
AS-03 Trucks and portable generator operating in vicinity of AS-03.
AS-04 X
AS-05 X Also downwind of Seep 9.
AS-06 X Residential receptor, operating upwind on Rte. 44.
AS-07 X Residential receptor; asphalt being applied at a downwind business location.
AS-08 Duplicate for AS-03.
DRAFT April 29. 1993
5.03.3 November 16. 1992
The following observations were noted at the site on this date:
• Invasive activities related to the RI were being conducted at well nest
MW-101.
• Material was being brought into the site for disposal during the sampling.
• The average temperature was approximately 32°F, according to the on-
site meteorological station and Bradley, the average barometric pressure
was 1029 millibars according to Bradley, and the wind was generally out
of the southwest at 5 miles per hour according to field observations, the
on-site meteorological station and Bradley. The wind direction did not
differ by more than 90° as compared to the historical data.
The following table presents the orientation of the sampling stations with
respect to the wind direction and pertinent observations that could influence the
interpretation of the air monitoring results:
Orientation to Landfill Sampling Observations - November 16. 1992
Upwind Downwind Station
AS-01 X Also downwind of invasive activity: drill rigs operating in vicinity of AS01.
AS-02 Downwind of Seep 6.
AS-03 On landfill; trucks and portable generator operating in vicinity of AS03.
AS-04 X
AS-05 X Also downwind of Seep 9.
AS-06 X Residential receptor.
AS-07 X Residential receptor.
AS-08 X Duplicate of AS-01
DRAFT 134 April 29, 1993
5.03.4 November 17. 1992
The following observations were noted at the site on this date:
• Invasive activities related to the RJ were being conducted at well nest
MW-101.
• Material was being brought into the site for disposal during the sampling.
• The average temperature was approximately 32°F, according to the on-
site meteorological station and Bradley, the average barometric pressure
was 1021 millibars according to Bradley, and the wind was generally out
of the southwest at less than 5 mph according to field observations, the
on-site meteorological station and Bradley. The wind direction did not
differ by more than 90° as compared to the historical data.
The following table presents the orientation of the sampling stations with
respect to the wind direction and pertinent observations that could influence the
interpretation of the air monitoring results:
Orientation to Landfill Sampling Observations -November 17. 1992
Upwind Downwind Station
AS-01 X Also downwind of invasive activi ty: drill rigs operating in vicinity of AS01.
AS-02 Downwind of Seep 6.
AS-03 On landfill; trucks and portable generator operating in vicinity of AS03.
AS-04
AS-05 X Downwind of Seep 9.
AS-06 X Residential receptor.
AS-07 X Residential receptor.
AS-08 X Duplicate of AS-01
DRAFT 135 April 29, 1993
5.04 Modifications
The sampling protocols established in the FSP and SOP were adhered to during
the environmental air sampling project. However, there were minor modifications from
the FSP sampling procedures necessitated by on-site field conditions. The following
statements identify the modifications, their rationale, and the corrective actions taken.
RAM-1
Airborne respirable particulate concentrations were measured
continuously by linking the MIE RAM-1 to a datalogger which electronically
compiled the results to provide average particulate concentrations. However, on
October 23, 1992 and November 16, 1992, the datalogger was not properly
operating and the continuous results could not be logged into the datalogger.
The corrective action taken was to use the airborne particulate measurements
collected on October 27, 1992 (non-invasive day) to establish background
conditions, and to use the measurements collected on November 17. 1992
(invasive day) to measure levels during "worst case" conditions. In addition, on
November 17. 1992 the datalogger was improperly programmed with the wrong
date, November 18. 1992. The proper date was noted when the data was being
transcribed.
Weather Station
On-site meteorological monitoring was conducted continuously during the
environmental air monitoring program for the following parameters:
• Horizontal wind speed and direction
• Ambient temperature
• Atmospheric pressure
DRAFT 136 April 29, 1993
However, on October 23, 1992, October 27, 1992, and in the morning of
November 16, 1992 the on-site meteorological station was not fully operational,
due to a defective circuit board in the digital processor. The corrective action
taken was to replace the defective board and collect meteorological information
from the closest airport (Bradley International). On-site data were also collected
using hand-held instruments. In-field observations were made throughout the
sampling event to correlate the airport and hand-held data. This information was
used to determine the sampling volumes and wind directions in place of the on-
site meteorological station.
Volatile Sample Blank
A volatile sample field blank was not collected on October 23, 1992.
Since samples and field blanks were collected in a similar manner during the
other sampling days, the field blank results from the other sampling dates were
used to correct the October 23, 1992 volatile data during the data validation
process.
Wind Direction
Sampling was to be postponed if the wind direction on the sampling date
differed by more than 90° as compared to the historical wind direction ( w i n d s
out of the southwest). However, on October 27, 1992, the wind was generally
out of the north north-west, which differs from the historical data by 180°. In
consultation with USEPA, the samples were collected on this date since invasive
activities were scheduled to begin on October 28, 1992. The locations of the
sampling stations on October 27, 1992 provided upwind and downwind site data,
DRAFT 137 April 29, 1993
downwind of point source data, and upwind and downwind receptor data, as
specified in the SOP.
5.05 Results
OSHA establishes PELs, while ACGIH establishes TLVs. Both PELs and TLVs
have been established to provide time weighted average concentrations for a normal 8
hour work day and a 40 hour work week, to which nearly all workers may be
repeatedly exposed, day after day, without adverse effects. OSHA PELs and ACGIH
TLVs have been established to provide a reference for industrial exposure settings and
area not intended to be utilized for evaluating community health issues.
Results of the environmental air monitoring are presented in Table 18. These
tables provide OSHA PELs and ACGIH TLVs for the parameters listed, their respective
sample locations, and the parameter concentration based on the volume of air collected.
The paniculate datalogger results are presented in Appendix I. The strip chart
recording of the meteorological data is provided in Appendix J and the meteorological
data collected at Bradley International Airport is provided in Appendix K. The
sampling survey data sheets are provided in Appendix L.
During the course of the sampling, cars and trucks were observed near and
upwind from the various sampling stations. The fuel used by vehicles may contain
benzene, toluene, ethylbenzene and xylene (BTEX) and the internal combustion of the
vehicles produces the components of BTEX. Therefore, the detection of BTEX at
concentrations below OSHA PELs and ACGIH TLVs may be attributed to the fuel used
by the vehicles and internal combustion.
DRAFT 138 April 29. 1993
5.06 Discussion
For all sampling events, all detected volatile and semivolatile compounds were
present at concentrations at least 100 times less than OSHA PELs and ACG1H TLVs.
5.06.1 Non-Invasive Site Activities
October 23. 1992
The following compounds were detected above their respective method
detection limits at one or more of the sampling stations, but not in the other
field blanks and not in the method blank:
• Carbon Tetrachloride
• Chlorobenzene
• Ethylbenzene
Carbon tetrachloride was detected at concentrations below the OSHA
PEL and ACGIH TLV at sampling stations AS-02 (downwind landfil l and
downwind seep), AS-01 (downwind landfill), AS-08 (center landfill dup l i ca te ) .
and AS-07 (downwind receptor).
Chlorobenzene was detected at a concentration below the OSHA P f - L and
ACGIH TLV at sampling station AS-02 (downwind landfill and downwind
seep).
Ethylbenzene was detected at sampling stations AS-03 (center landfill.
AS-08 (center landfill duplicate, AS-02 (downwind landfill and downwind seep).
AS-01 (downwind landfill) and AS-07 (downwind receptor). These results may
be attributed to the fuel used by the vehicles and internal combustion.
DRAFT 139 April 29. 1993
The following substances were detected in the samples at concentrations
below OSHA PELs and ACGIH TLV, and in the field blanks collected during
the other sampling dates:
• Benzene
• m,p-Xy!ene
• o-Xylene
• Tetrachloroethane
The following substances were detected in the samples at concentrations
below OSHA PELs and ACGIH TLV, and in the method blank:
• 1,1,1 -Trichloroethane
• 2-Butanone
• Acetone
• Methylene chloride
• Toluene
Bis(2-ethylhexyl)phthalate
• Di-n-butylphthalate
October 27. 1992
The following compounds were detected above their respective method
detection limits at one or more of the sampling stations and not in the field or
method blanks:
• Carbon Tetrachloride
• Ethylbenzene
DRAFT 140 April 29, 1993
Carbon tetrachloride was detected at concentrations below the OSHA
PEL and ACGIH TLV at all of the sampling stations, except AS-04 (downwind
landfill).
Ethylbenzene was detected, slightly above the method detection limit, at
sampling station AS-06 (downwind receptor) and AS-08 (downwind landfill and
seep) . This result may be attributed to the fuel used by the vehicles and the
internal combustion.
The following substances were detected in the samples at concentrations
below OSHA PELs and ACGIH TLV, and in the field blanks collected during
the sampling date:
• Benzene
• m,p-Xylene
• o-Xylene
Tetrachloroethane
• 1,1,1-Trichloroethane
• 2-Butanone
• Acetone
• Methylene chloride
• Toluene
• Di-n-butylphthalate.
The fol lowing substances were detected in the samples at concentration
below OSHA PELs and ACGIH TLV and in the method blank:
• 1.1.1-Trtchloroethane
• o-X\Iene
DRAFT 141 April 29, 1993
• Acetone
• Methylene chloride
• Di-n-butylphthalate
The average participate concentration at AS-01 (upwind landfill) was
below the OSHA PEL and ACGIH TLV.
5.06.2 Invasive Site Activities
November 16. 1992
The following compounds were detected above their respective method
detection limits at one or more of the sampling stations and not in the field or
method blanks:
• 1,1 -Dichloroethane
• Benzene
• Carbon Tetrachloride
• Ethylbenzene
• m,p-Xylene
• o-Xylene
1,1-Dichloroethane was detected slightly above the method detection l imit
at concentrations below the OSHA PEL and ACGIH TLV at AS-08 (invasive
activity duplicate sample).
Benzene, ethylbenzene, and m,p,o-Xylene were detected at the landfill
sampling station AS-03, These results were below the appropriate OSHA PELs
and ACGIH TLVs. These results attributed to the fuel used by the vehicles and
the internal combustion.
DRAFT 142 April 29, 1993
Carbon tetrachloride was detected at concentrations below the OSHA
PEL and ACGIH TLV at AS-04 (upwind of landfill), AS-03 (center landfill),
AS-02 (upwind of the landfill and downwind seep), AS-08 (invasive activity
duplicate), AS-05 (downwind landfill and seep), and AS-07 (downwind
receptor).
The following substances were detected in the samples at concentrations
below OSHA PELs and ACGIH TLV and in the field blanks collected during
the sampling date:
• 1,1,1 -Trichloroethane
• Acetone
• Methylene chloride
• Toluene
• Di-n-butylphthalate
. The following substances were detected in the samples at concentrations
below OSHA PELs and ACGIH TLV and in the method blank:
• Acetone
• Methylene chloride
• Di-n-butylphthalate
November 17. 1992
The following compounds were detected above their respective method
detection limits at one or more of the sampling stations and were not detected
in the method blank:
• Carbon Tetrachloride
• Chlorobenzene
DRAFT 143 April 29, 1993
Carbon tetrachloride was detected at concentrations below the OSHA
PEL and ACGIH TLV at AS-04 (upwind of landfill), AS-03 (center of the
landfill), AS-02 (upwind of the landfill and downwind of a seep), AS-01
(invasive activity), and AS-08 (invasive activity duplicate).
Chlorobenzene was detected at a concentration below the OSHA PEL and
ACGIH TLV at sampling station AS-02 (upwind of the landfill and downwind
seep).
The following substances were detected in the samples at concentrations
below OSHA PELs and ACGIH TLV and in the field blanks collected during
the sampling date:
• 1,1,1-Trichloroethane
Acetone
• Benzene
• Carbon Disulfide
• Ethylbenzene
• m,p-Xylene
• Methylene chloride
• o-Xylene
• Styrene
• Tetrachloroethene
• Toluene
• Di-n-but>lphthalate
The following substances were detected in the samples at concentration
below OSHA PELs and ACGIH TLV and in the method blank:
DRAFT 144 April 29. 1993
• 1,1,1-Trichloroethane,
• Methylene chloride
• Di-n-butylphthalate
The average particulate concentration at AS-01 (invasive activity) was
below the OSHA PEL and ACGIH TLV.
5.07 Summary
Compounds were collected at the on-site sampling stations, upwind and
downwind off-site sampling stations, and at the receptors sampling stations during non
invasive and invasive activities. The results of the monitoring were below OSHA PELs
and/or ACGIH TLVs by at least two orders of magnitude. OSHA PELs and ACGIH
TLVs have been established to provide industrial exposure limits for health adult
workers over an 8 hour work day and a 40 hour work week. Since the volatile and
semivolatile levels were well below the OSHA PELs and/or ACGIH TLVs. it is
concluded that the site did not impact the quality of air being transported off-site.
DRAFT 145 April 29, 1993
SECTION 6 - SURFACE WATER. LEACHATE AND SEDIMENTS
6.01 General
A total of 15 surface water and 16 sediment samples were collected between
October 27 and November 6, 1992, to characterize the surface water and sediment
quality and to identify the current and/or potential adverse impacts the Barkhamsted Site
may have on the on-site surface waters and sediments, as well as the potential for
transport of these media off-site. The surface water and sediment sampling locations
are illustrated on Figure 34.
Nine leachate seeps were sampled between October 29 and December 11. 1992.
Leachate sampling was performed to characterize and quantify the contaminants in the
leachate, and to identify the potential impacts that the leachate may have had on the
surface waters and/or sediments.
Four storm sewer samples were collected to evaluate the impact the landfill mav
be having on storm water generated on site. Two samples were collected from
catchment basins on site and samples were collected from the two outfalls discharging
storm water to the Unnamed Brook. The location of storm sewer samples are bho\vn
in Figure 34.
6.02 Methods
Surface \vater sampling locations were chosen to evaluate the surface water and
sediment qualitv in samples collected at areas upgradient of the landfill (indicative of
background condit ions) , at on-site areas of concern, and at areas downgradient of the
DRAFT [46 April 29. 1993
landfill. Specific rational for each surface water and sediment sampling location is
explained in the FSP, contained within the RI Work Plan.
Surface water samples were collected approximately 6 inches below the uater
surface at the midpoint of each stream. Pond surface water samples were collected at
the bank of each pond. Surface water samples were collected prior to the collection of
associated sediment samples in order to avoid suspension of sediments which may have
become dispersed in the water column Prior to filling sample containers, a
representative portion of surface water was analyzed in the field for pH, temperature,
conductivity, and dissolved oxygen (Table 19). Water samples were col'ected by
immersing unpreserved sample containers just below the water surface. Preserved
sample containers were filled by collecting water in a decanting vessel and then
decanting the sample into the preserved containers. The decanting vessel \vas
decontaminated in accordance with the procedures outlined in FSP Appendix FSP-D
Surface water samples were analyzed for hardness and the TCL/TAL parameters
outlined on Table 5.
Sediment samples were collected in the same vicinity of each surface uatcr
sample immediately after collection of surface water samples. A stainless steel spoon
was utilized for the collection of each sediment sample. Sediment samples \\ere
collected approximately 6 inches below the sediment surface and placed in a stainless
steel bowl. Excess water was decanted from the sample. Sample containers were then
filled with the sediment in the stainless steel bowl using a stainless steel spoon.
Sediment sampling equipment was decontaminated in accordance with the procedures
outlined in FSP Appendix FSP-D. Sediment samples were analyzed for the TCL/TAL
DRAFT 147 April 29. 1993
parameters outlined on Table 5 and for total organic carbon. In addition, sediment
samples were analyzed for grain size using ASTM Method D422.
A total of twelve leachate seeps were mapped and the approximate volume of
flow at each seep was estimated as described in Section 2.05. During the leachate
mapping task, a sample from each seep was collected in a glass jar, covered with
aluminum foil, agitated for approximately 30 seconds and screened with a flame
ionizing detector (FID). Results of FID screening are included in Table 19. Final
leachate sample collection locations were based on field screening, volume of leachate
flow, and potential impacts on surface water bodies along with concurrence from the
USEPA.
Leachate samples were collected at the locations illustrated on Figure 34. Where
leachate seeps did not have sufficient flow for immediate sampling, a hole was dug with
a decontaminated spade, into which was placed a stainless steel bowl flush to the
ground surface. Enough leachate was allowed to collect in the bowl to provide for
sample collection. Prior to leachate sample collection, a representative portion of each
leachate seep was field tested for pH. temperature, conductivity, and dissolved o\> gen
(Table 19). Sample containers were filled by decanting the leachate liquid from the
stainless steel bowl. Leachate samples were analyzed for TOC, BOD, and hardness.
along with the TCL/TAL parameters outlined on Table 5.
Leachate sediments were collected from four leachate seep locations as shown
in Figure 34. Leachate sediments were collected in a stainless steel bowl using a
stainless steel spoon. Leachate sediments were then placed into the appropriate sample
containers. Leachate sampling equipment was decontaminated in accordance with the
procedures outlined in FSP Appendix FSP-D. Leachate sediments were analyzed for
DRAFT 148 April 29. 1993
the TCL/TAL parameters outlined on Table 5 and for total organic carbon. In addition.
sediment samples were analyzed for grain size using ASTM Method D422.
Field Modifications
Surface water was not present at SW/SED-1 and therefore only a sediment
sample was collected.
6.03 Surface Water Results
The following is a discussion of the surface water analytical results upgradient,
in the vicinity of the landfill disposal area, and downgradient of the landfill disposal
area.
Upgradient Surface Water Samples
Surface water samples SW-3 and SW-4 were collected in the Unnamed Brook,
upgradient of the landfill disposal area (Figure 34). Results of the TCL/TAL analyses
for volatiles, semivolatiles, pesticides/PCBs and metals are presented on Tables 20A
through 20D, repsectively, and are as follows:
• VOCs were not detected in the upgradient surface water samples.
• SVOCs were not detected in the upgradient surface water samples.
• PCB/pesticides were not detected in the upgradient surface water samples.
• The metal constituents detected in SW-3 and SW-4 included:
Upgradient metal concentrations are similar in SW/SED-3 and SW SED
4. providing a range in which to compare downgradient samples.
Metal concentrations do not exceed federal ambient water level criteria
(AWLQ) for water and fish ingestion with the exception of iron in SW-3
which is approximately four times greater than the AWLQ (Table 20D)
DRAFT 149 April 29. 1993
Proximal to Landfill Disposal Area
Surface water samples SW-2, SW-5, SW-6, SW-14, SW-15, and SW-16 were
collected in the vicinity of the landfill disposal area as shown in Figure 34. Results of
the TCL/TAL analyses are as follows:
• VOCs were not detected in the vicinity of the landfill disposal area.
• The semivolatile compounds diethylphthalate and 2,4-dimethylphenol were
detected in SW-15 and di-n-butylpthalate was detected in SW-6 at estimated
concentrations below the quantitation limit. The compound 4-methylphenol was
detected in SW-15 at 16 /zg/L.
• The pesticide 4,4-DDT was detected in SW-15 at an estimated concentration
below the quantitation limit.
• Elevated metal concentrations were detected in the vicinity of the landfill
disposal area. Results are as follows:
The bulk of elevated metal concentrations were detected in SW-15 and
ranged from less than two times background (lead and zinc) to 134 times
background (manganese).
Manganese concentrations were greater than both background and the
AQWL in SW-2, SW-5, SW-14, SW-15. and SW-16.
Iron was greater than background and the AQWL in SW-15 and SW-16.
Downgradient of the Landfill Disposal Area
Surface water samples SW-7, SW-8, SW-9, SW-10, SW-ll; SW-12, and SW-13
were collected downgradient of the landfill disposal area off the RRDD#1 property as
shown in Figure 34. Results of TCL/TAL analyses for these samples are as follows:
• TCL volatile results include:
DRAFT 150 April 29. 1993
Estimated concentrations of acetone and butanone were detected below
the quantitation limit in SW-8.
Acetone was detected in SW-7 and SW-9 at 11.0 /xg/L and below the
quantitation limit, respectively.
Methylene chloride was detected in SW-10 at an estimated concentration
below the quantitation limit.
An estimated concentration of toluene was detected below the
quantitation limit in SW-9.
• All SVOCs detected in the downgradient surface water samples were below the
quantitation limit.
• PCB/pesticides were not detected in the downgradient surface water samples.
• TAL metal results are discussed as follows:
Elevated metal concentrations were detected in all downgradient surface
water samples.
Manganese was the most elevated metal in all downgradient samples
ranging from 23 times higher than background in SW-11 to 60 times
background in SW-9. All manganese concentrations in the downeradient
surface water samples exceeded the AQWL.
• Iron concentrations exceeded the AQWL in all downgradient surface
water samples. Elevated iron concentrations in downgradient samples
were no more than two times background.
• Mercury was detected in SW-13 at 1 /ig/L which is greater than the
AQWL.
DRAFT 151 April 29, 1993
Discussion of Surface Water Quality Results
Results of surface water analysis indicated that the surface water in the vicinity
of and downgradient of RRDD#1 is impacted by the landfill. Elevated metal
concentrations are the most significant impact that the landfill has on the surface water.
The highest metal concentrations have been detected in the vicinity of leachate seep
discharges to the Unnamed Brook (SW-13, SW-15, and SW-16).
6.04 Leachate Seep Results
The results of leachate seep TCL/TAL analysis are included in Tables 21A to
21D and discussed below:
• A total of 12 VOCs were detected in the leachate seeps.
Acetone was detected in Seep 1 and Seep 11 at 300 /ig/L.
Benzene was detected in Seep 4, Seep 5, and Seep 7, and Seep 12 at
concentrations below the quantitation limit. Benzene was detected at 1 2
Hg/L in Seep 11.
Chlorobenzene was detected in Seep 4 and Seep 7 at concentrations
below the quantitation limit and 77 ^tg'L. respectively.
Chloromethane was detected below the quantitation limit in Seep 5.
2-Butanone was detected in Seep 1 and Seep 11 at 370 ^g/L and 680
jig/L, respectively.
Ethylbenzene was detected in Seep 7 and Seep 11 at 12 /zg/L, 120 /ig. L.
and 14 jig L. respectively.
4-Methyl-2-pentanone was detected in Seep 1 and Seep 11 at 45 /xg/L.
and 120 /zg/L. respectively.
DRAFT 152 April 29. 1993
Toluene was detected in Seep 1 and Seep 11 at 100 /ig/L and 4700 jug/L,
respectively.
Xylenes were detected in Seep 7 and Seep 11 at 31 jug/L and 34 /xg/L,
respectively.
Chloroethane was detected in Seep 11 at 25 /ig/L.
Methylene chloride was detected at an estimated concentration below the
quantitation limit in Seep 12.
Chloroform was detected at an estimated concentration below the
quantitation limit in Seep 11.
• Seep SVOC analytical results were rejected as discussed in the Validation
Report.
• PCB/pesticides were not detected in the seep samples with the exception of Seep
7 which detected dieldrin at an estimated concentration below the detection
limit.
• Seep TAL metal analytical results are discussed below:
Seep 12 contains the highest metal concentrations. This may be due to
the distance the ground water travels from the landfill prior to
discharging in Town of Barkhamsted gravel excavation.
Arsenic was detected in Seep 3, Seep 7, and Seep 11 below the
quantitation limit.
Copper was detected in Seep 11 and Seep 12 28.6 /xg/L and 183 ^g/L.
respectively. Copper was below the quantitation limit in all other seep
samples.
DRAFT 153 April 29. 1993
Chromium was detected in Seep 7 at 15.1 /zg/L. All other concentrations
were below the quantitation limit.
Lead was detected in Seep 4 through Seep 12 at estimated concentrations
greater the quantitation limit. Concentrations ranged from 4.5 ^g/L
(Seep 7) to 111 ^g/L (Seep 12).
Mercury was detected in Seep 12 at 0.39 jig/L.
Cyanide was detected in Seep 1, Seep 7 and Seep 10 at estimated
concentrations of 6.3 jig/L, 16.6 /xg/L, and 40.3 pg/L, respectively.
Seep VOC and elevated metal concentrations are consistent with those detected
in other site sample matrices (i.e. soils, ground water). The leachate seeps are directly
impacting the Unnamed Brook water quality.
6.05 Surface Water Sediment Results
The following is a discussion of the surface water sediment analytical results
upgradient, in the vicinity of the landfill disposal area, and downgradient of the landfill
disposal area. Results of the TCL/TAL analyses for volatiles. semivolat i les.
pesticides/PCBs and metals are presented on Tables 22A through 22D. respectively
Upgradient of Landfill Disposal Area
Surface water sediment samples SED-3 and SED-4 were collected in the
Unnamed Brook, upgradient of the landfill disposal area (Figure 34). Results of the
TCL/TAL analyses are as follows:
• VOCs were not detected in the upgradient surface water sediment samples.
• Four SVOCs were detected in the upgradient surface water sediment samples.
All were at estimated concentrations below the quantitation limits.
DRAFT . 154 April 29. 1993
• PCB/pesticides were not detected in the upgradient surface water sediment
samples.
• Upgradient metal concentrations were similar in SED-3 and SED-4 and provide
a range in which to compare downgradient samples.
Proximal to Landfill Disposal Area
Surface water sediment samples SED-1, SED-2, SED-5, SED-6, SED-14,
SED-15, and SED-16 were collected in the vicinity of the landfill disposal area as
shown in Figure 34. Results of the TCL/TAL analyses are as follows:
• TCL volatile analyses detected acetone in SED-6 and SED-15 at 13 MS/kg ^d
41 (j.gfkg, respectively.
• Twenty-one SVOCs were in surface water sediment samples proximal to the
landfill. Most constituents were detected below the quantitation limit with the
exception of the following:
SED-2 detected benzo(b)fluoranthene, fluoranthene, and pyrene at 610
/ig/kg, 460 /zg/kg> and 610 ng/kg, respectively.
• PCB/pesticides results are discussed as follows:
4,4-DDT and methoxychlor was detected in SED-1 below the
quantitation limit.
4,4-DDT was detected in SED-2 at 3.7 jig/kg-
Gamma chlordane was detected in SED-2 and SED-6 at 6.6 ^g/kg and
3.9 Mg^g- respectively.
PCB Aroclor-1254 was detected in SED-2 and SED-6 at 110 /ig/kg and
190 /ig/kg, respectively.
DRAFT 155 April 29, 1993
4,4-DDE was detected in SED-2 and SED-6 at 5.8 Mg.'kg and 9.6 /xg/kg,
respectively.
Endosulfan II was detected in SED-2 and SED-6 at 4.0 /zg/kg and 8.9
/xg/kg, respectively.
4,4-DDD, endrin, endrin ketone, and methoxychlor were detected in
SED-2 below the quantitation limit.
Endrin was detected in SED-6 at 3.8 ng/kg.
4,4-DDT, endrin ketone, and methoxychlor were detected in SED-6
below the quantitation limit.
• Elevated metal concentrations were detected in the vicinity of the landfill
disposal area. Results are as follows:
Silver, chromium, and sodium were detected in SED-5 at concentrations
less than two times background.
Copper and potassium were detected in SED-2 at concentrations less than
two times background.
Potassium and thallium were detected in SED-14. The potassium
concentration was less than two times background and thal l ium \\as less
than the quantitation limit.
Downgradient of the Landfill Disposal Area
Surface water sediment samples SED-7, SED-8, SED-9, SED-10, SED-11. SED
12, and SED-13 were collected downgradient of the landfill disposal area off the
RRDD#1 property as shown in Figure 34.
• TCL volatile results are discussed as follows:
• SVOC results are discussed as follows:
DRAFT 156 April 29, 1993
Thirteen SVOCs were detected in SED-9 ranging from less than the
quantitation limit to 340 //g/kg (pyrene).
Fifteen SVOCs were detected in SED-11 ranging from less than the
quantitation limit to 2300 /ig/kg (pyrene).
Fifteen SVOCs were detected in SED-12 ranging from less than the
quantitation limit to 950 /ig/kg (di-n-burylphthalate).
Acetone was detected in SED-6, -12, -13 and -15 at concentrations
ranging from 13 /xg/kg m SED-6 to 190 /xg/kg m SED-16.
Butanone was detected in SED-12 at a concentration of 52 Mg^g
SED-10 and SED-13 exhibited SVOCs below the quantitation limit.
• PCB/pesticides results are discussed as follows:
Gamma chlordane was detected in SED-9 at 1.8 Mg/kg-
The following constituents were detected in SED-11: PCB Arochlor-1254
at 80 /zg/kg; gamma chlordane at 6.3 /ug/kg; 4.4-DDD at 4.3 p.ejkg; 4.4
DDE at 6.2 jxg^g; an^ 4,4-DDT and methoxyclor at less than the
quantitation limit.
Gamma chlordane was detected in SED-12 at 3.8 jig/kg; 4.4-DDD at 4 b
/xg/L; 4.4-DDE at 4.8 /^g/kg; and methoxyclor at less than the
quantitation limit.
• TAL metal results are discussed as follows:
All downgradient sediment elevated metal concentrations were less than
two times the background values.
Mercury was detected in SED-11 at 0.26 /xg/kg.
DRAFT 157 April 29, 1993
As indicated from the sediment analyses surface water sediments have been
impacted by the landfill activities. Landfill precipitation runoff and leachate seeps are
continuing to impact surface water sediments.
6.06 Leachate Seep Sediment Results
The results of leachate seep sediment TCL/TAL analyses for volatiles,
semivolatiles, pesticides/PCBs and metals are included in Tables 22A to 22D,
respectively, and discussed below:
The VOC acetone was detected in Seep/SED-5 and Seep/SED-6 at
concentrations of 150 Mg/kg, 250 jig/kg> respectively.
• SVOCs were detected in all leachate sediments and are discussed as follows:
Six SVOCs were detected in Seep/SED-4 at concentrations less than the
quantitation limits.
Ten SVOCs were detected in Seep/SED-5 at concentrations less than the
quantitation limit.
The following SVOCs were detected in Seep/SED-6: benzol b)
fluoranthene at 770 jig/kg; fluoranthene at 540 ^g/kg; and pyrene at 490
jig/kg. The remaining twelve SVOCs were detected at concentrations
less than the quantitation limit.
The following SVOCs were detected in Seep/SED-11: benzo(a)
anthracene at 340 /xg/kg; benzo(b)fluoranthene at 620 /zg/kg; fluoranthene
at 840 Mg^g; phenanthrene at 420 /xg/kg; and pyrene at 600 /xg/kg. The
remaining fourteen SVOCs were detected at concentrations less than the
detection limit.
DRAFT 158 April 29. 1993
PCB/Pesticides results are discussed as follows:
4,4-DDE was detected in Seep/SED-4 at 3.4
Gamma chlordane, PCB Aroclor -1254 and 4,4-DDE were detected in
Seep/SED-5 at 4.4 ng/kg, 42 Mg/kg and 3.7 Mi/kg, respectively. Aldrin
and alpha-chlordane were detected at concentrations less than the
quantitation limit.
The following constituents were detected in Seep/SED-6: 4,4-DDD at 14
Mg/kg, 4,4-DDE at 10 Mg/kg, 4,4-DDT at 15 jug/kg, and alpha chlordane
at 4.7 /xg/kg. Dieldrin was detected at a concentration less than the
quantitation limit.
• Metal concentrations are consistent between the leachate seep sediments.
Leachate seep sediments exhibit contaminants consistent with those observed in
the leachate seeps.
6.07 Storm Sewer Sampling Results
Catchment basins #6 and #15 (CB-6 and CB-15) and storm sewer outfall 31 and
#2 (OS-1 and OS-2) were sampled for the TCLTAL parameters listed in Table 5. The
locations of these samples are shown in Figure 34. The results of analyses for volatiles.
semivolatiles, pesticides/PCBs and metals are presented on Tables 23A through 23D,
respectively, and discussed below:
• The volatile compounds detected included acetone, toluene and methylene
chloride. Acetone was detected in CB-15 at 53 Mg/kg- Toluene was detected
in OS-2, and methylene chloride was detected in CB-6 and CB-15 below the
quantilation limit.
DRAFT 159 April 29, 1993
• The semi volatile compound butylbenzylphthalate was detected at estimated
concentrations below the quantitation limit in OS-2.
• PCB/pesticides were not detected in the storm sewer system.
• The highest metal concentrations were detected in CB-15. The metals detected
included cyanide and cadmium which were below the quantitation limits.
Mercury was detected at 0.46 jig/kg.
Catchment basin #15 is the most impacted storm sewer component sampled during the
Phase 1A RI. The basin was sampled because ground water was observed seeping into
the basin through the side walls. CB-15 is located in close proximity to the landfill
disposal area and appears to be draining ground water impacted by the landfill disposal
area.
DRAFT 160 April 29. 1993
SECTION 7 - QUALITATIVE ECOLOGICAL ASSESSMENT
7.01 Introduction
This section presents a Phase I qualitative Ecological Assessment (EA) for the
site. The EA was designed in a phased approach to assess whether on-site ecological
receptors could be exposed to site-related compounds before deciding if additional
activities needed to be conducted to evaluate risk or potential off-site impacts.
The EA was performed based on information obtained from regulatory agencies
and two O'Brien & Gere Engineers, Inc. (O'Brien & Gere) site visits conducted on
December 26, 1991, for the Limited Field Investigation (O'Brien & Gere, 1992a) and
October 20-23, 1992 for the EA. The Phase I EA was designed in accordance with
Risk Assessment Guidance for Superjund Volume II Environmental Evaluation Manual
(USEPA, 1989a), and Ecological Assessment of Hazardous Waste Sites: A Field and
Laboratory Reference (USEPA. 1989b). The specific objectives of the Phase I EA are
to:
• Identify potential fish and wildlife receptors in the study area.
• Qualitatively evaluate the potential impacts of exposures to site-related
chemicals on the identified receptors, and
• Evaluate the potential for off-site impacts.
O'Brien & Gere designed this EA, and its associated field elements, to collect
the information necessary to meet the objectives of the Phase I EA. Based on USEPA
Work Plan comments (USEPA, I992a) reflected in the approved Work Plan (O'Brien
& Gere, 1992b), USEPA will perform the identification of compounds of concern, the
determination of exposure point concentrations, and the evaluation of wildlife exposure
DRAFT 161 April 29, 1993
pathways typically performed in a Phase I EA. Therefore, consistent with the Work
Plan (O'Brien & Gere 1992b), this Phase I EA focuses exclusively on the identification
of potential wildlife receptors based on information requests and field evaluations of
wildlife inhabitation, and presents this information to USEPA for its evaluation of
impact. However, an independent continuation of this EA may be performed by
O'Brien & Gere for comparative purposes.
The following five tasks were performed to meet the objectives of this Phase I
EA: 1) Covertype Analysis, 2) Wildlife Receptor Evaluation, 3) Wildlife Habitat
Quality Evaluation 4) Qualitative Impact Evaluation, and 5) Potential for Off-site
Impacts. The scope and results of these tasks are presented in the following sections.
7.02 Covertvpe Analysis
The objective of the covertype analysis is to identify the major vegetative
communities and their distribution within 0.5 miles of the site (the study area). The
0.5-mile radius was selected for this site because it incorporates the major covertvpes
in the vicinity of the site from which transient wildlife could visit the site and
potentially be exposed to site-related compounds. The covertype map (Figure 35)
presents the relative sizes and positions of each identified covertype. The covertvpe
map was prepared based on information extracted from existing maps, literature review,
aerial and general photograph review, and a qualitative vegetative census performed
during site visits. Natural terrestrial covertypes were classified according to a
conventional classification scheme for New England forested and nonforested habitats
(DeGraff et al.. 1992)
DRAFT 162 April 29, 1993
The following subsections present a general description of the site and
assessment area followed by detailed descriptions of each identified covert\pe.
7.02.1 Site and Study Area Description
As presented in the Work Plan (O'Brien & Gere, 1992b), the site consists
of the RRDD# 1 property and the area between the eastern boundary and Route
44. The site includes active and inactive landfill areas surrounded primarily by
mixed hardwood and conifer forests. Active landfill areas are essentially void
of vegetation. Inactive landfill areas have revegetated with old field/shrub plant
species. The site includes one surface water body, the Unnamed Brook, which
originates south of the site, and flows north along the west side of the landfill
area. The brook flows northeast on-site towards and under Route 44. Various
buildings and roads, associated with active recycling operations at the facility,
are present on the site.
Also as presented in the Work Plan (O'Brien & Gere, 1992b). the studv
area consists of the site and the area traversed by the Unnamed Brook to its
confluence with the Farmington River. Once the Unnamed Brook crosses Route
44, it enters the Farmington River floodplain and runs southeast through a series
of small beaver ponds. South of the ponds, the brook runs along the base of a
steep embankment along the eastern side of Route 44 before entering the
Farmington River approximately 0.25 mi southeast of the site. The floodplain
area is characterized by a mixture of forested upland areas, open fields, and
seasonally saturated wetlands.
DRAFT 163 April 29. 1993
Terrestrial, wetland, and aquatic ecological covertypes were identified in
the study area by O'Brien & Gere. Dominant terrestrial covertypes consisted
of white pine-northern hardwood forest, Eastern hemlock forest, old field/shrub,
landfill, and paved/cultural areas. Wetland covertypes consisted of National
Wetland Inventory (NW1) wetlands for off-site areas and delineated wetlands for
on-site areas. On-site wetlands were identified and delineated by O'Brien and
Gere based on current federal guidelines (Environmental Laboratory, 1987). The
aquatic communities in the study area include the Unnamed Brook with
associated beaver ponds, a small pond located northwest of the site, and the
Farmington River. Although the surface water areas are also considered NWI
wetlands, they are discussed as aquatic covertypes in this EA. The physical
characteristics of each covertype are described in the following sections.
7.02.2 Terrestrial Covertvpes
White Pine-Northern Hardwood Forest
The landfill area is surrounded by mixed hardwoods and conifers tvpical
of a white pine-northern hardwood forest covertvpe. Off-site, this coxerupe is
found in upland areas of the Farmington River floodplain. Dominant canopy
species in this covertype consist of Northern red oak (Quercus nigra), red
maple (Acer rubrum). Eastern white pine (Pinus strobus), sugar maple (Acer
saccharum), white oak (Quercus alba), American beech (Fagus grandifolia),
white birch (Betula papyrifera), gray birch (Betula populifolia), and Eastern
hemlock (Ttuga canadensis). Dominant trees in this covertype are
DRAFT 164 April 29. 1993
approximately 12 to 16 inches in diameter, indicative of a middle-aged stand.
The majority of the canopy is closed, resulting in a limited shrub layer.
Understory shrubs and saplings consist of mountain laurel (Kalmia latifolia),
Northern red oak, red maple, white oak, Eastern hemlock, and Eastern white
pine. The herbaceous layer varied with the degree of canopy closure supporting
ferns such as Christmas fern (Polystichum acrostichoides) and New York fem
(Thelypteris noveboracensis). A list of vegetation observed in the white pine-
northern hardwood forest is presented in Table 24.
Eastern Hemlock Forest
Southwest of the landfill is a relatively small Eastern hemlock forest,
dominated by Eastern hemlock with lesser numbers of white birch interspersed.
Trees in this covertype are approximately 6 to 14 inches in diameter. In areas
where the canopy is dense, the sapling layer consists primarily of eastern
hemlock and white birch. The herbaceous layer was essentially lacking in this
covertype likely due to the closed canopy and the acidity of the soil caused by
the hemlock. A list of vegetation observed in the Eastern hemlock forest is
presented in Table 25.
Old Field/Shrub
Portions of the inactive landfill and the area between Route 44 and the
Farmington River are communities best described as an old field/shrub
covertype. Portions of the old field/shrub areas near the Farmington River are
seasonally Hooded, Periodically, portions of this area are mowed by
Connecticut Department of Environmental Protection (CTDEP) to maintain early
DRAFT 165 April 29. 1993
successional vegetation for its wildlife value (Wilson, 1993). These areas
provide rich floodplain type habitat, dominated by tall grasses and herbaceous
vegetation such as golden rod (Solidago spp.), sedges (Carex spp.), grasses
(Bromus spp.), greenbrier (Smilax spp.), and staghorn sumac (Rhus typhina).
Inactive landfill areas are also representative of this covertype, resulting from
revegetation following landfill disturbances. A list of vegetation observed in the
old field/shrub covertype is presented in Table 26.
Active Landfill
The active landfill covertype is the area that receives fill material and soil
covering. No vegetation was observed in the active portions because of the soil
disturbances.
Cultural/Paved Areas
The cultural/paved area covertype includes man-made structures (i.e.
buildings, roads) constructed for human use. Cultural/paved areas within the
study area consist of Route 44, access roads to the landfill, the recycling
buildings and office, a Department of Transportation salt storage facility, and
residential homes. These areas are not vegetated except for ornamental lawns
included in this covertype.
7.02.3 Wetland Covertvpe
The presence of wetlands within 0.5 miles of the site was evaluated
through a review of NWI maps, the Litchfield County soil survey, and by
delineating wetland boundaries in accordance with current federal methodology.
DRAFT 166 April 29, 1993
Dominant tree species observed in the wetland areas include American elm
(Ulmus americana), cottonwood (Populus deltoides), honeylocust (Gleditsia
triacanthos), American sycamore (Platanus occidentalis), American hornbeam
(Carpinus caroliniana), and silver maple (Acer saccharinurri). Common shrub
species include dogwoods (Cornus spp.), and golden rod. No submerged or
emergent vegetation was observed in the main channel, however adjacent
inundated areas contained grasses and herbaceous vegetation tolerant of wet
conditions. A list of vegetation observed in the wetland covertype is presented
in Table 27.
Each of the identified wetland types is discussed below.
NWI Wetlands
The NWI maps present classifications of wetlands using alphabetical and
numerical designations developed by Lewis M. Cowardin (Cowardin, 1979) for
the U.S. Fish and Wildlife Service (USFWS) which describe hydrologic and
vegetative characteristics of the wetland. The NWI maps present \vetland
boundaries on topographic maps based on USFWS wetland criteria established
as an indicator of waterfowl production areas. NWI wetlands are not intended
for federal regulatory purposes. Figure 36 presents the locations of NWI
wetlands within a 0.5-mile radius of the site.
A review of the NWI maps for the area indicates that one USFWS
designated wetland occurs on the site, the Unnamed Brook. The Unnamed
Brook, flowing from southwest to northeast across the site, is classified as
PFO4E - a palustrine, forested, needle-leaved evergreen, seasonally saturated.
DRAFT 167 April 29. 1993
North and east of the site, the Unnamed Brook runs through several palustrine
wetland areas classified as: PFO1C - forested, broad-leaved deciduous,
seasonal; PFO/SS1A -forested/scrub/shrub, broad-leaved deciduous, temporary;
PSS1C - scrub/shrub, broad-leaved deciduous, seasonal; PSS1/EME
scrub/shrub/emergent, broad-leaved deciduous, seasonal saturated; PEMA
emergent, temporary; PEMC - emergent, seasonal; and PEMFb - emergent,
semipermanent, beaver.
The Farmington River and Unnamed Brook wetland areas east of Route
44 are the most extensive wetlands in the study area. The Farmington River
floodplain, reaching approximately 1000 feet in width, contains two palustrine
wetlands classified as PF01A - forested, broad-leaved deciduous, temporary; and
PFQ1C - forested, broad-leaved deciduous, seasonal. The Farmington River is
classified as R3OWH - riverine, upper perennial, open water, permanent.
Other palustrine wetlands within 0.5 miles of the site include POWH
open water, permanent - a small pond located northwest of the site; PFO1E
forested, broad-leaved deciduous, seasonal saturated - a small intermittent stream
north of the site; and PFO4E - forested, needle-leaved evergreen, seasonal
saturated - an intermittent stream north of the site.
State of Connecticut Wetlands
Wetlands are defined and regulated by the State of Connecticut based on
soil type (Flores. 1992). The Litchfield County soil survey (USDA, 1970) was
reviewed to identify the soil types on the site. Identified soil types were
compared to the Connecticut List of Map Units that Qualify as Wetland Soils.
Based on this review, Leicester, Ridgebury, and Whitman very stony fine sandy
DRAFT 168 April 29, 1993
loam, designated "Lg" on the soil map, is the only wetland soil occurring in the
study area. Figure 37 presents the location of this wetland soil in the study area.
Federal Wetlands
Wetlands are defined and regulated at the federal level by the US Army
Corps of Engineers (ACOE) and USEPA. The currently accepted federal
method for wetland identification and delineation is the 1987 Army Corps of
Engineers Wetland Delineation Manual (Environmental Laboratory, 1987). In
accordance with this manual, wetland criteria require the presence of hydric
soils, a dominance of hydrophytic vegetation, and wetland hydrology.
Consistent with the Work Plan (O'Brien & Gere, 1992b), only on-site wetlands
were identified and delineated. Although it is recognized that the Unnamed
Brook is a wetland, wetlands were only delineated in those areas that met the
criteria outside of the main brook channel. Six wetlands were delineated on the
site by O'Brien & Gere in accordance with the 1987 ACOE method. The
wetland areas include a small isolated pond on the northern portion of the site.
two isolated sedimentation basins located south and west of the landfill , and
three areas along the Unnamed Brook. Along the Unnamed Brook, two
wetlands were located on either side of the old stone bridge, and the third
wetland was associated with the headwaters of the brook, leading towards the
western site boundary. The wetland boundaries are presented'in Figure 38.
Documentation of the wetland boundaries is presented in O'Brien & Gere's
Wetland Delineation Report (O'Brien & Gere, 1993) which is presented in
Appendix A.
DRAFT 169 April 29. 1993
Using the Cowardin system of classification, the six identified wetlands
would be classified as follows: the small pond. POWF - palustrme. open water,
permanent; the sedimentation basins, PUBhx - unconsolidated bottom, permanent
excavated; and the areas along the Unnamed Brook, PFO1Y - forested, broad
leaved deciduous, saturated/semi-permanent/seasonal.
Wetland Functions and Values
In accordance with the Work Plan (O'Brien & Gere, 1992b), the
functions and values of non-isolated wetlands, potentially impacted by the
landfill, were evaluated using the Wetland Evaluation Technique (WET)
developed by Paul Adamus for the ACOE (Environmental Laboratory 1987).
WET evaluates the functions and values of wetlands based on their physical,
chemical, and biological characteristics. The WET analysis is presented in
Appendix M.
The delineated wetlands on either side of the old stone bridge were
identified as the Assessment Area (AA) tor the WET analysis as these wetlands
are the only non-isolated wetlands that occur on-site and downgradient of the
landfill. WET was run using current conditions and average flow regime^ The
watershed of the AA was identified as the input zone and the locality for the
evaluation, and the Farmington River was identified as the Service Area. Table
28 summarizes the results of the WET analysis.
DRAFT 170 April 29. 1993
7.02.4 Aquatic Covertvpes
The aquatic covertypes include the Unnamed Brook on-site, the Unnamed
Brook off-site, a small pond on the northern portion of the site, and the
Farmington River. A discussion of each of these areas is presented below.
The Unnamed Brook originates southwest of the landfill and flows north
along the western boundary of the landfill. Average width and depth ranged
from approximately 2 to 4 feet and 1 to 8 inches, respectively. The flow rate
varied from 4 to 12 inches/second over a substrate containing mostly rocks and
boulders. The brook consists primarily of riffles with an occasional small (6 to
8 inch) pool. No submerged or emergent vegetation was observed in the main
channel. The portion adjacent to the landfill contained water with an orange
coloration. Water was clear in the more southern portion of the brook. No fish
species were observed. Amphibians and aquatic macroinvertebrates inhabited
the brook. Physical characteristics (DO, pH, specific conductance, temperature)
of the Unnamed Brook on-site are presented in Table 19. On-site Unnamed
Brook surface water sampling locations are designated SW-4. SW-05. SW-06.
SW-07, SW-09, SW-10. SW-13. SW-14. and SW-I5.
The off-site portion of the Unnamed Brook flows into the Farmington
River floodplain where it is temporarily impounded by a series of beaver dams
between forested upland areas. The first and northernmost pond was 4 to 6
inches deep over a muddy substrate. The average depth of the other ponds was
approximately 3 to 4 feet. The brook continues south along the eastern edge of
Route 44 before converging with the Farmington River approximately 0.25 mi
southeast of the site. The width and depth of the brook downstream of the
DRAFT 171 April 29, 1993
beaver ponds ranged from approximately 2 to 10 feet and 1 to 8 inches,
respectively. The flow rate was approximately 12 inches/second over a rocky
substrate. Portions of the brook contained submerged grasses. Physical
characteristics (DO, pH, specific conductance, temperature) of the Unnamed
Brook off-site are presented in Table 19. Off-site Unnamed Brook sample
locations are SW-11 and SW-12.
The small (approx. 3500 sq ft) pond, located in the northwest portion of
the site occurs in a forested area. Runoff from steep adjacent terrain collects in
this localized depression which is approximately 2 to 3 feet deep. High flows
of the Unnamed Brook may enter this pond at times. Overflow from the pond
could discharge to the Unnamed Brook. No submerged or emergent vegetation
was observed during field investigations. Physical Characteristics (DO, pH,
specific conductance, temperature) of the pond are presented in Table 19. The
pond sample location is SW-8.
The west branch of the Farmington River is located east of the site. The
average width is approximately 200 feet. Average flow rate, measured in
Unionville, CT. seasonally fluctuates between 1 and 7 feet/second (Cemone.
1993). The river's substrate is rocky and the average water depth ranges from
3 to 6 ft. The western shoreline is relatively flat and rises approximately 5 ft
above the observed water level. The eastern shoreline is relatively steep, rising
approximately 20 to 40 ft above the observed water level. This segment of the
river is being considered for listing as a Wild and Scenic River under the Wild
and Scenic Rners Act of 1968. Figure 39 presents the 100-year and 500-year
floodplain zones for the Farmington River and a small southern portion of the
DRAFT 172 April 29, 1993
Unnamed Brook. No surface water samples were collected from the Farmington
River.
7.03 Wildlife Receptor Evaluation
The objective of this task is to identify wildlife species that inhabit the study
area that could potentially be exposed to site-related compounds. Ecological receptors
were identified through contact with state and federal agencies, during transects walked
specifically for this purpose during site visits, and by identifying typical inhabitants of
the identified covertypes through literature review. Resident and transient fish or
wildlife species that frequent the site or adjacent areas were identified based on actual
sightings; observations of wildlife indicators such as nesting places, burrows, tracks,
scat or browse; or audible indicators such as bird songs.
7.03.1 Special Resources
According to U.S. EPA (1989a), potential ecological receptors inc lude
special resources such as environmentally sensitive areas: significant habitats .
rare, threatened or endangered species (RTE): regulated wetlands: streams: lakes.
and Wild and Scenic rivers. The objective of this task is to identify special
resources within the study area. Special resources were identified through
contact with state and federal agencies and review of the NW1 maps.
Rare. Threatened, or Endangered Species
Information'regarding the presence of RTE wildlife species in the vicinity
of the site was provided by CTDEP, Natural Diversity Data Base and the
USFWS. Information from the above agencies was requested for a 2 mile radius
DRAFT . 173 April 29. 1993
from the site to account for the larger home range of some RTE species.
According to CTDEP Natural Diversity Data Base, there are no known extant
populations of Federally Endangered and Threatened Species or species
proposed for State Endangered, Threatened or Special Concern occurring at the
site (Meltzer, 1992). According to the USFWS, no Federally listed or proposed,
threatened and endangered species under the jurisdiction of the USFWS are
known to occur within 2 miles of the project area (Beckett, 1992). However,
the CTDEP Wildlife Division indicated that wintering bald eagles (Haliaeetus
leucocephalus), which have migrated from the north, use the Farmington River
habitat during the winter months for feeding and resting. The bald eagle is
listed as an endangered species in the State of Connecticut as well as federally.
Bald eagles nesting in the Barkhamsted Reservoir area (more than 2 miles away)
may use the Farmington River as a feeding site during the summer months
(Wilson. 1993).
Regulated Wetlands
Wetlands in the study area were previously identified and discussed in
Section 1.02.3 of this EA.
Wild and Scenic Rivers
According to the National Park Service (NPS), two segments of the
Farmington River are currently being studied and considered for listing as Wild
and Scenic Rivers under the Wild and Scenic Rivers Act of 1968 (Huffman,
1993). One segment is located in Massachusetts and the other begins in
Hartland. Connecticut and extends 14 miles downstream to the southern extent
of the New Hartford - Canton town line including the segment east of the site.
DRAFT 174 April 29, 1993
Study segments are subject to the same protective status as a listed river,
requiring NFS approval for any water resources project requiring federal
assistance (permit, license, funding etc.) that may adversely impact the study
segment (Huffman, 1993).
7.03.2 Terrestrial Habitat Receptors
Several transects were walked during a 4-day site visit in the fall to
identify terrestrial mammals, amphibians, reptiles, and resident and migratory
birds. Terrestrial wildlife species observed in the study area are summarized in
Table 29. Typical wildlife inhabitants of the terrestrial covertypes, as identified
in the literature, are presented in Table 30.
7.03.3 Palustrine Habitat Receptors
With the exception of bird species, direct animal sightings were limited
during the O'Brien & Gere site visits. Bird species observed in the Farmington
River wetland area include Northern cardinal (Cardinalis cardinally}. Northern
mockingbird (\limus polygloitos). Eastern bluebird ( Stalls stalls), and tut ted
titmouse (Parus bicolor). In addition, a Northern oriole (Icterus galbula) nest
was also sited. White-tailed deer (Odocoileus virginiana) tracks indicated recent
activity in this area. Typical wildlife inhabitants of palustrine habitats, as
identified in the literature, are presented in Table 31.
DRAFT 175 . April 29. 1993
7.03.4 Aquatic Habitat Receptors
The surface water of the Unnamed Brook was surveyed for
macroinvertebrates using USEPA kick net sampling techniques (USEPA, 1989c).
The invertebrate assessment was performed in the Unnamed Brook at three
locations: at the furthest downstream location on-site (Assessment Area #1);
adjacent to the landfill (Assessment Area #2); and upstream (west) of the landfill
(Assessment Area #3). Both rocky and sandy substrates were sampled at each
location except for the location upstream of the landfill, where sandy substrate
could not be found. Macroinvertebrates were counted in a 10 sq ft section of
water at each location. Sufficient quantities of macroinvertebrates were not
present for statistical analysis of potential population effects but do provide an
indication of the benthic community. Table 32 summarizes the observed
macroinvertebrates at each location.
No fish were observed in any surface waters of the site. A brook trout
was observed being caught by a fisherman on the Farmington River during field
investigations. The CTDEP Division of Fisheries indicated that the ent i re
segment of the Farmington River in the study area is located wi th in a 3 5 mi le
trout management area which is stocked with brook trout (Salvelinus Jontmalis)
and rainbow trout (Oncorhynchus mykiss) for recreational fishing (Hyatt, 1993a).
Atlantic salmon (Salmo salar) and long-nose dace (Rhinichthys cataractae) are
reported to be abundant in this portion of the river. (Hyatt. 1993a). Table 33
lists other common fish species of this segment of the Farmington River. The
Unnamed Brook, near the point of confluence with the Farmington River, is
seasonally used primarily by minnow (Family Cyprinidae), darters (Family
DRAFT 176 April 29. 1993
Percidae), and trout (Hyatt, 1993b). However, no resident fish species are
known to inhabit the brook (Hyatt, 1993b)
Beaver (Castor canadensis) activity was apparent along the beaver ponds
of the Unnamed Brook, east of Route 44 Freshly gnawed trees and old dams
and lodges were observed, however, no beaver were sited.
7.04 Wildlife Habitat Quality Evaluation
The objective of the habitat quality evaluation is to use the information gathered
during previous tasks to evaluate the ability of study area covertypes to provide the life
sustaining requirements of the identified ecological receptors. High quality habitat
provides sufficient size and resource to support either ecologically or economically
important single species, or a diverse ecological community. Low quality habitat lacks
sufficient size or resource to support important species or diverse communities
The active landfill and cultural/paved covertypes do not provide ^utf ic ient
quantities of vegetation for food or cover and are, therefore, considered to be poor
quality wildlife habitats and are not further discussed in this section
7.04.1 Terrestrial Covertypes
The uhite pine-northern hardwood covertype, containing mixed
hardwoods and conifers, is considered a high quality habitat for a variety of
wildlife species The oak and beech trees of the canopy and understory provide
high quahtv habitat for mast feeding species such as gray squirrel (Sciurus
carolinem>u>>, turkey ( \feleagris gallopavo) and deer, and also provide value as
DRAFT 177 April 29, 1993
cover. The food sources and roosting areas provided by birch and hemlock,
respectively, provide a good habitat tor ruffed grouse (Bonasa umbelIns) The
mixed hardwood and conifer forest is preferred habitat for many reptiles, birds
and mammals (DeGraff et al., 1992)
The Eastern hemlock forest covertype also provides abundant cover for
wildlife, but offers fewer food sources than the white pine-northern hardwood
forest. It is preferred habitat for many bird species, small mammals, and for
wintering white-tailed deer (Degraff et al.,1992).
The old field/shrub covertype provides minimal cover or shelter for
wildlife, however many birds and small mammals use these areas for feeding.
The old field/shrub area located in the Farmington.River floodplain is owned by
the Metropolitan District Commission Water Company and is leased by the state
to provide wildlife based recreation to the public (Wilson, 1993). The area is
open to small game hunting during the season and is stocked with pheasants
(Wilson. 1993). This is a high use area for hunting (Wilson. 1993) This
covertype provides food and cover for many bird species and small mammals
(Degraff et al.. 1992).
7.04.2 Palustrine Wetlands
The wetland areas on the site do not provide sufficient water depth and
food sources to attract aquatic furbearers such as beaver, muskrat (Ondatra
:ibethica}. or mink (Mustela vison), or waterfowl such as the wood duck (Aix
sponsa). Vegetation browsers such as the white-tailed deer would find sufficient
DRAFT 178 April 29. 1993
food, cover, and water in this covertype to consider this a good qualin habitat.
This covertype is also suitable for a variety of reptiles and amphibians.
Palustrine wetlands in the off-site areas adjacent to the Farmington River
are considered higher quality habitats than the on-site wetlands because of their
proximity and accessibility to the Farmington River. This area would, therefore,
be considered high quality habitat for most of the species discussed above.
7.04.3 Surface Waters
The Farmington River is the highest quality aquatic habitat of the surface
waters in the study area. This major river provides important riparian and
associated wetland habitat for a vast number of wildlife species (Wilson, 1993).
Its physical characteristics, with alternating pools, riffles, runs, and deep water
areas, provide good habitat for trout and salmon species. The presence of trout
and other fish species provide food sources for aquatic furbearers such as mink
and piscivorous birds such as the great blue heron (Ardea herodias).
The beaver ponds of the off-site portions of the Unnamed Brook are of
sufficient size and depth to support the fish. bird, and aquatic furbearcr species
which inhabit the Farmington River and are therefore considered to be high
quality aquatic habitats.
In contrast, the Unnamed Brook on the site is not a high quality aquatic
habitat because it does not support a fish population. The shallow water depths,
low. intermittent flows, absence of submerged and emergent vegetation; and
small macro invertebrate populations provide insufficient habitat requirements to
support economically important fish species. However, it likely provides
DRAFT 179 April 29. 1993
drinking water for terrestrial wi ld l i fe and an acceptable environment for a
variety of amphibians and reptiles Depending on the amount of rainfall in the
spring and summer, portions of the Unnamed Brook may be dry during the
summer months
The small pond near the Unnamed Brook is of sufficient depth to support
some non-game fish species; however, its small size and lack of vegetation
provide insufficient habitat requirements to support economically important fish.
This pond could provide habitat for a variety of reptiles and amphibians
7.05 Qualitative Impact Evaluation
The fish and wildlife species that inhabit the different covertypes of the study
area are considered potential ecological receptors for exposures to site-related
compounds. A qualitative evaluation of impact to these receptors requires the
identification of a means of exposure and an evaluation of the result of the exposure
Means of exposure consist of dermal contact, ingestion. or inhalation of site-related
contaminants. The presence of site-related contaminants in surface waters ot the studs
area could result in exposures to aquatic and terrestrial ecological receptors \quat ic
organisms could be exposed to contaminants via uptake from the ambient water or
through the consumption of contaminated sediments, macromvertebrates, vegetation, or
contaminated prey fish Terrestrial wildlife could be exposed via ingestion or dermal
contact with contaminated surface water, soil, vegetation, or lower food chain
organisms. Food chain exposures could result in bioaccumulation of contaminants in
the higher food chain organisms ( i e worms) USEPA has indicated that it will use the
site-related compound concentrations detected in surface water, sediments, and soils to
DRAFT 180 April 29, 1993
evaluate exposure point concentrations and model exposures to indicator \\ildlife species
to determine if a potential for unacceptable risk exists for the site (USEPA. 1992b).
The effects of contaminant exposure on aquatic macroinvertebrates can be
evaluated based on observed community structure comparisons between impacted and
control areas. USEPA guidance (USEPA, 1989c) discusses the evaluation of impacts
to macroinvertebrate populations based on the presence and abundance of members of
the Ephemeroptera (mayfly), Plecoptera (stonefly), and Trichoptera (caddisfly) Orders.
Statistical population comparisons were not included in the scope of this assessment,
however the macroinvertebrate community was evaluated from limited data collected
as part of potential stream receptor identification efforts. Macroinvertegrates were
collected from sediments in 10 sq ft areas located upstream, adjacent to, and
downstream of the landfill. The results of this effort are presented in Table 32. As can
be seen from Table 32, organisms from these Orders were only identified in the
upgradient macroinvertegrate assessment area.
The effects of contaminant exposure on particular wildlife species is a funct ion
of the exposure concentrations, the duration of the exposure, and the sensit i \ i t> ot the
exposed species. State (CDEP. 1992) and Federal (USEPA. 1992b) Ambient \Vater
Quality Criteria (AWQC) have been developed by the CDEP and the L'SEPA.
respectively, for the protection of aquatic life. AWQC were used to screen contaminant
concentrations detected in surface waters of the site and vicinity. Exceedance of
AWQC does not necessarily reflect an unacceptable condition. Exceedance of the
reference criteria may trigger the performance of additional Steps of the EA process.
However, because of the safety factor approach used in their derivation, exceedance of
the criteria do not necessarily indicate an unacceptable level of risk to ecological
DRAFT 181 April 29. 1993
receptors. Iron, lead, mercury, and zinc concentrations in on-site surface waters slightly
exceed USEPA AWQC for chronic exposures in aquatic environments. Zinc also
exceeds acute USEPA AWQC at one location. Exceedance of the criteria during a
single sampling event is another uncertainty in the evaluation of whether an impact is
occurring or has occurred. The detected concentrations could represent intermittent
contaminant releases, or be indicative of a constant release of low levels.
A comparison of detected compound concentrations in surface water with
Connecticut AWQC was also performed. No volatile or semivolatile exceedances of
criteria were identified. No metal detections were found to exceed criteria but accurate
comparisons for all metals were not possible. The detected total copper, lead and zinc
concentrations in surface water exceed the State AWQC but the criteria apply only to
the soluble fraction of the samples. In accordance with the Work Plan (O'Brien &
Gere, 1992b), the analyzed surface water samples were not filtered prior to analysis.
In addition, the state criterion for mercury only applies to methyl mercury, \vhich was
not analyzed at the site. Therefore, an evaluation of the significance of the detected
concentrations of copper, lead, zinc and mercury could not be performed.
Therefore, an evaluation of impacts can not be performed at this time, based on
a single round of sampling data. An evaluation of potential impacts to ecological
receptors of the site would best be performed based on the results of at least a second
round of surface water and sediment sampling and analysis.
Potential impacts to on-site wetlands downgradient of the landfill were
qualitatively evaluated based on the results of the WET analysis. An impact could
result to a wetland it' the opportunity to provide a function is higher than the
effectiveness of the wetland at performing that function. In the WET analysis, only the
DRAFT 182 April 29, 1993
function of nutrient removal/transformation had a LOW effectiveness and a HIGH
opportunity. The HIGH opportunity stems from potential nutrient inputs from the
adjacent landfill area. The LOW effectiveness ranking results from the lack of aquatic
vegetation and fine organic sediments in the main channel to retain, uptake and
transform nutrients. The input of more nutrients than the AA could effectively absorb
would not have a negative impact in a flowing water environment but would allow
nutrients to be transported downstream.
The impact of a toxicant release into the AA can be evaluated based on the
concentration of the release. High concentrations could result in toxicity to vegetation
and aquatic organisms and reduce the quality of the AA. However, currently detected
concentrations of contaminants have not resulted in observable vegetative stress and the
WET analysis has evaluated the AA's ability to retain toxicants to be effectively HIGH.
Therefore, it does not appear that the landfill is impacting the functions and \alues of
the evaluated wetland, but potential wetland inhabitants may be exposed to toxicants
in the wetland.
7.06 Potential For Off-Site Impacts
The objective of this task is to evaluate the potential for off-site impacts to
ecological receptors. Chemical concentrations detected in off-site surface \vater and
sediment samples were evaluated to determine if site-related chemicals have migrated
to off-site areas at concentrations that could impact ecological receptors. As an init ial
screening step, off-site surface water contaminant concentrations were compared to
State and Federal AWQC. Two surface water samples were collected from off-site
portions of the Unnamed Brook in the Farmington River floodplain.
DRAFT 183 April 29, 1993
Lead, copper and zinc were the only compounds found to exceed the Federal
chronic AWQC in off-site sampling locations. Zinc was also found to exceed acute
Federal AWQC. No volatile or semivolatile exceedances of State AWQC criteria were
identified. No metal detections were found to exceed State AWQC criteria but accurate
comparisons for all metals were not possible. The detected total lead, copper, and zinc
concentrations in surface water exceed the State AWQC but the criteria apply only to
the soluble fraction of the samples. In accordance with the Work P:lan (O'Brien &
Gere, 1992b), the analyzed surface water samples were not filtered prior to analysis.
Therefore, an evaluation of the significance of the detected concentrations of lead,
copper, and zinc could not be performed.
A background surface water sample, collected upgradient of the site, also
exceeds Federal AWQC for iron, indicating that iron occurs at elevated concentrations
in the vicinity of the site, upgradient to the influence of the landfill. A single sample
is not statistically representative of background, however the iron detection may indicate
either naturally elevated concentrations in the region or an upgradient source of iron
entering the Brook. High iron concentrations in background surface \vater uould
eliminate iron from further consideration at the detected concentrations xvhich onl>
slightly exceed Federal AWQC. Background iron concentrations will be further
evaluated following subsequent surface water quality sampling and analysis.
The presence of contaminants in off-site surface waters indicates that
contaminants may have been released in the past or during different flow and/or
leachate conditions than when the first round of sampling was conducted. However,
no chemical concentrations exceeded Federal AWQC in the surface water sample
located at the furthest downstream location on the site. This information suggests that
DRAFT 184 April 29, 1993
contaminants were not being transported off-site at the time of sampling at levels which
give rise to exceedance of the Federal AWQC in surface water. Contaminant
concentrations in the water could change in response to higher or lower flows and
changes in leachate generation. Therefore, an evaluation of off-site impacts should be
deferred until additional rounds of surface water samples can be collected, representing
a variety of leachate and flow conditions.
DRAFT 185 April 29. 1993
SECTION 8 - SUMMARY AND CONCLUSIONS
8.01 General
The following provides a summary of the Phase 1A Site Characterization results
with respect to each individual area of investigation. In addition, conclusions are
presented with regard to the adequacy of the Phase 1A Site Characterization for the
purpose of completing a Feasibility Study (FS).
8.02 Summary
50/75 and Sources of Contamination
The geophysical and soil gas surveys were effectively utilized to
delineate the horizontal extent of potential source areas. Results of each
survey served to focus invasive investigations (soil borings).
Resistivity surveys provided correlatable resolution of water table and
bedrock elevations in several locations of the site.
The results of the landfill gas survey indicated that methane gas is
limited to the vicinity of fill areas.
Surface soil sampling results provided validated data for the USEPA risk
assessment. In addition, analytical data correlated with the horizontal
extent of contamination as defined by the soil boring sampling program.
Surface soil sampling of the Yahne property detected low levels of
pesticides. Surface soil sampling of the Jones/Murray property detected
low levels of semi-volatile constituents.
DRAFT 186 April 29, 1993
The soil boring installation program provided analytical and physical
characterization of each potential source area. The results revealed that
with the exception of a few discrete soil samples, contaminants were
below the USEPA action levels.
Site Hydrogeologic Characterization
Geologically, the site consists of predominantly ice contact and glacial
outwash/fluvial overburden deposits which overly a pegmatite intruded
micaceous schist metamorphic bedrock.
Hydrogeologically, the site consists of an overburden aquifer which is
hydraulically connected to the bedrock aquifer. The bedrock, which is
moderately to highly fractured, acts as single hydraulic unit.
Ground water flow direction is similar in overburden and the bedrock.
Flow is to the north on RRDD#1 property in the vicinity of the landfill
disposal area. Ground water flow diverts to the northeast, and flows off
the RRDD#1 property, north of the landfill disposal area in the vicinity
of the Unnamed Brook. Ground water from the site discharges in the
Farmington River Flood Plain.
The ground water contaminant plume consists of VOCs, semivolatiles.
and elevated metal concentrations. Contaminant plume VOC and
semivolatile concentrations were similar in the vicinity of the landfill
disposal area; however, VOC concentrations exceed semivolatile
concentrations downgradient. Therefore VOC concentrations were
utilized to assess the maximum extent of the ground water contaminant
plume at the Barkhamsted Site.
DRAFT 187 April 29, 1993
The local ground water users obtain water supplies from multiple zones
within the overburden and bedrock aquifers. Water supply wells range
in depth from shallow hand-dug wells to 500 foot bedrock wells.
Air Quality Assessment
The results of air monitoring found that during both non-invasive and
invasive activities , air analyte concentrations were below OSHA PELs
and/or ACGIH TLVs by at least two orders of magnitude.
Surface Water, Leachate, and Sediments
Surface water samples collected upgradient of the landfill disposal area
detected iron above the Federal AWQL criteria for water and fish
ingestion. All other analytes were below method detection limits.
Low levels of VOCs, semivolatiles, pesticides, and elevated metal
concentrations were detected in the surface water samples proximal to
and downgradient of the landfill disposal area.
Twelve leachate seeps were identified at the Barkhamsted Site. Fen ot'
the seeps discharge either directly or indirectly via the storm ^euer
system to the Unnamed Brook. One seep originates on the Barkhamsted
Town Garage property, flows overland a short distance and infiltrates
into the ground.
Seep analytical samples detected VOCs and elevated metal
concentrations.
Analysis of stream sediments proximal to and downgradient of the
landfill disposal area detected VOCs, semivolatiles, PCBs/pesticides. and
elevated metal concentrations.
DRAFT 188 April 29, 1993
The storm sewer system is impacted by the landfill disposal area. Seep
#11 discharges directly to the storm sewer system. Catchment basin #15
collects ground water which has been impacted by the landfill disposal
area.
Ecological Assessment
The ecological assessment identified terrestrial, wetland and aquatic
covertypes in the vicinity of the Barkhamsted Site. In addition, the
wildlife receptors which reside in and around the covertypes were
identified.
Iron, lead, mercury, and zinc in on-site surface waters exceeded the
USEPA AWQC for chronic exposures in aquatic environments.
Comparison of detected compounds in surface waters to the Connecticut
AWQC found VOCs and semivolatiles did not exceed the criteria.
Based on WET analysis, the landfill is not impacting the functions and
values of on site wetlands. However, potential wetland inhabitants mav
be exposed to toxicants in the wetland.
Lead, copper, and zinc concentrations in off-site surface water s l i g h t K
exceeded Federal chronic AWQC criteria.
DRAFT 189 April 29, 1993
8.Q3 Conclusions
The Phase 1A Site Characterization has provided sufficient data to identify and
characterize all potential source areas, evaluate the nature and extent of contaminants,
and assess the environmental effects resulting from releases from the site. The data
generated during the Phase 1A Remedial Investigation will be sufficient for use in
screening and evaluating remedial alternatives. In addition, data has been generated for
the USEPA Risk Assessment.
The following has been concluded from the results of the Phase 1A Site
Characterization:
The results of the soil boring and test pit installations indicate that the
limits of fill encompass potential source Area A, Area B, and the eastern
portion of Area C.
The revised limits of fill increase the landfill disposal area to
approximately 13 acres.
The result of the soils and sources of contamination investigation indica te
that source areas do not exist outside the landfill disposal area.
Therefore, potential disposal Areas A through L, PreviousK Cleared
Areas #1 and #2 and the Recycling Area do not need to be considered
as contaminant sources independently from the landfill disposal area.
The overburden aquifer is hydraulically connected to the Unnamed
Brook.
Higher contaminant concentrations exist in the overburden aquifer and
decrease with increasing depth into the bedrock aquifer.
DRAFT 190 April 29, 1993
The contaminant plume from the Barkhamsted Site migrates with ground
water flow. The plume flows north in the vicinity of the landfill disposal
area, then diverts to the northeast, north of the landfill disposal area in
the vicinity of the Unnamed Brook, and flows off the RRDD#1 property
and discharges to the Farmington River Floodplain.
Results of the domestic supply well sampling program indicate that the
domestic supply wells in the vicinity of the site are not impacted by the
site related contaminants.
The surface water in the vicinity and immediately downgradient of the
Barkhamsted Site is being impacted by the landfill in the form of
elevated metal concentrations. The highest elevated metal concentrations
have been detected in the vicinity of leachate seep discharges to the
Unnamed Brook.
Volatile and semi-volatile airborne constituents were below OSHA PELs
and/or ACGIH TLVs indicating the site does not impact the quality of
air being transported off site.
DRAFT 191 April 29, 1993
References
QBRIEN G GERE ENGINEERS, INC.
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