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EVALUATION OF THE TERRESTRIAL ECOSYSTEM

OF THE HOUSATONIC RIVER VALLEY

JULY 26,1994

preparedfor:

The General Electric Company 100 Woodlawn Avenue

Pittsfield, Massachusetts 01201

prepared by:

ChemRisk A Division of McLaren/Hart

Stroudwater Crossing 1685 Congress Street

Portland, Maine 04102 (207) 774-0012

in collaboration with:

S.G. Martin & Associates, Inc. 7121 N. County Road 9 Wellington, CO 80549

(303) 568-9333

A Division of McLaren/HartEnvironmental Engineering

r fBcyc/ed paper oioH25

Area Environmental & Facility Programs General Electric Company 100 Woodlawn Avenue, Pittsfield, MA 01201

July 26, 1994

Ms. J. Lyn Cutler Section Chief, Special Projects Department of Environmental Protection 436 Dwight Street Springfield, MA 01103

Mr. Bryan Olson U.S. Environmental Protection Agency Waste Management Division J.F. Kennedy Federal Building HRR-CAN3 Boston, MA 02203

Re: Housatonic River (DEP # 1-0147P, EPA Permit Area 6) Terrestrial Ecosystem Assessment

Dear Ms. Cutler and Mr. Olson:

Enclosed for your review is a report entitled "Evaluation of the Terrestrial Ecosystem of the Housatonic River Valley," prepared by ChemRisk in collaboration with Dr. Stephen G. Martin, a terrestrial ecological expert. This report describes the methodology and results of their study of the health of terrestrial wildlife potentially exposed to PCBs in the Housatonic River floodplain.

In consultation with ChemRisk, GE plans to use this report as one basis for the ecological risk assessment of the Housatonic River.

We look forward to discussing this report with the DEP and EPA at our meeting on August 18. Please call me if you have any questions.

Sincerely yours,

Johohnn D. Ciampa Project Manager

Enclosure

- 2

cc: Alan Weinberg, DEP WERO Stephen F. Joyce, DEP Office of Commissioner Robert Bell, DEP WERO Stephen P. Winslow, DEP Susan Steenstrup, DEP WERO Carol Rowan West, DEP ORS Meg Harvey, DEP ORS Gary B. Gosbee, EPA Region I Douglas J. Luckerman, EPA Region I Ruth Bleyler, EPA Region I Ronald F. Desgroseilliers, GE Stephen C. Moore, GE Andrew J. Thomas, Jr., GE Ellen S. Ebert, ChemRisk Stephen G. Martin, Ph.D., S.G. Martin & Associates Daniel M. Woltering, ENVIRON Robert K. Goldman, Blasland, Bouck & Lee James R. Bieke, Shea & Gardner Public Information Repositories (ECL I-R-IV(A)(1))

EVALUATION OF THE TERRESTRIAL ECOSYSTEM

OF THE HOUSATONIC RIVER VALLEY

prepared for:

The General Electric Company 100 Woodlawn Avenue

Pittsfield, Massachusetts 01201

prepared by:

ChemRisk Division of McLaren/Hart

Stroudwater Crossing 1685 Congress Street

Portland, Maine 04102 (207) 774-0012

July 26,1994 Reviewed and Approved By:

Miranda HenningTask Manager

C_3 'Date Ellen E.Ebert Project Manager

Russell E. Keenan, Ph.D.Principal-In-Charge

Date

ChemRisk A Division of McLaren/Hart Environmental Engineering

ChemRisk - A Division of McLaren/Hart July 26,1994

TABLE OF CONTENTS

1.0 INTRODUCTION 1-1

2.0 METHODS 2-1

2.1 Ecosystem Selected for Evaluation 2-1 2.1.1 Characterization of Habitats 2-3 2.1.2 Selection of Indicator Species 2-4

2.2 Characterization of Exposure Scenarios 2-4 2.2.1 Small Mammal Exposure Profile 2-5 2.2.2 Song Bird Exposure Profile 2-6

2.3 Selection of Endpoints 2-7

2.4 Selection of Study Areas 2-8 2.4.1 Flood Plain Forest Target Areas 2-8 2.4.2 Shrub Meadow Study Areas 2-10 2.4.3 Characterization of PCBs in Flood Plain Soils and River Sediments 2-11

2.5 Ecological Assessment Methods 2-14 2.5.1 Method of Comparing Target Areas and Reference Areas 2-14 2.5.2 Method for Evaluating Avian Population Structure 2-15 2.5.3 Method for Evaluating Avian Reproductive Success 2-17 2.5.4 Method for Evaluating Small Mammal Population Structure 2-21 2.5.5 Method for Evaluating Small Mammal Age Structure 2-22 2.5.6 Method for Evaluating Small Mammal Reproductive Success . . . . 2-22

3.0 RESULTS 3-1

3.1 Avian Population Structure 3-2 3.1.1 Avian Population Structure in the Massachusetts Target Area 3-2 3.1.2 Avian Population Structure in the Maryland Reference Area 3-3 3.1.3 Avian Population Structure in the North Carolina Reference Area . . . 3-4 3.1.4 Summary of Findings on Avian Population Structure 3-5

3.2 Avian Reproductive Success 3-7 3.2.1. Clutch Sizes 3-7 3.2.2 Young Hatched 3-8 3.2.3 Hatching Success 3-9 3.2.4 Summary of Findings on Avian Reproductive Success 3-9

3.3 Small Mammal Population and Density 3-9 3.3.1 Population and Density of White-Footed Mice and Southern Red-

Backed Voles 3-9 3.3.2 Population and Density of Shrews 3-11 3.3.3 Summary of Findings on Small Mammal Populations and Density . 3-11

ChemRisk - A Division of McLaren/Hart July 26, 1994

TABLE OF CONTENTS (CONT'D)

3.4 Small Mammal Age Structure 3-11 3.4.1. Findings on White-Footed Mice and Southern Red-Backed Voles . 3-12 3.4.2 Summary of Findings on Small Mammal Age Structure 3-12

3.5 Small Mammal Reproductive Success 3-13 3.5.1 Reproductive Success of White-Footed Mice and Southern

RedBacked Voles 3-13 3.5.2 Reproductive Success of Shrews 3-14 3.5.3 Summary of Findings on Small Mammal Reproductive Success ... 3-15

3.6 Additional Ecological Data 3-15 3.6.1. Observations of Wildlife Species 3-15 3.6.2 Summary of Findings on Additional Ecological Data 3-17

4.0 DISCUSSION 4-1

4.1 Uncertainty Analysis 4-1

4.2 Discussion of Results 4-4 4.2.1 Absence of a Species Normally Expected to be Present 4-4 4.2.2 Reduction of a Population or Subpopulation 4-5 4.2.3 Change in Community Structure 4-6 4.2.4 Bioaccumulation Associated with an Adverse Effect 4-7

4.3 Conclusions 4-8

5.0 REFERENCES 5-1

Appendix A - Selection of Indicator Species

Appendix B - Comparison of Target Areas and Reference Areas

Appendix C - Results of Statistical Analyses of Avian Reproductive Data


LIST OF FIGURES

Figure 2-1 Map of the Housatonic River Flood Plain Between Lenox Rd. & Woods Pond Dam 2-2a

Figure 2-2 Summary of River Sediment and Flood Plain Soil Sampling Results & Study Area Locations 2-2b

Figure 2-3 Summary of River Sediment and Flood Plain Soil Sampling Results & Study Area Locations 2-2c

Figure 2-4 Summary of River Sediment and Flood Plain Soil Sampling Results & Study Area Locations 2-2d

Figure 2-5 Summary of River Sediment and Flood Plain Soil Sampling Results & Study Area Locations 2-2e

Figure 2-6 Avian Census Observation Route 2-15a

Figure 3-1 Nest Heights of Avian Species Observed in Massachusetts Target Area . . . . 3-2a

Figure 3-2 Avian Population Study: Density 3-5c

Figure 3-3 Avian Population Study: Plot Size and Number of Species 3-6a

Figure 3-4 Avian Population Study: Diversity 3-6b

Figure 3-5 Avian Reproduction Evaluation: Clutch Size 3-7a

Figure 3-6 Comparison of Observed Clutch Sizes to Ranges Reported in the Literature . 3-8a

Figure 3-7 Avian Reporoduction Evaluation: Young Hatched 3-8b


LIST OF TABLES

Table 2-1 Rationale for Selection of Indictor Species 2-4a

Table 2-2 Ecosystem Characterization 2-4b

Table 2-3 Exposure Analysis Summary 2-4c

Table 2-4 Candidate Reference Areas and Rationale for Exclusion 2-9a

Table 2-5 Summary of April 27 - June 7,1994 Flood Plain Soil Sampling and Analysis Program 2-13a

Table 3-1 Summary of 1993 Avian Census Results for Massachusetts Target Area . . . . 3-2b

Table 3-2 Summary of 1991 Avian Census Results for Maryland Reference Area . . . . 3-3a

Table 3-3 Summary of 1991 Avian Census Results for North Carolina Reference Area 3-4a

Table 3-4 Comparison of Avian Census Results 3-5a

Table 3-5 Comparison of Species Densitiies in Three Reference Areas and in the Literature (territories/40ha) 3-5b

Table 3-6 Small Mammal Population Estimates 3-10a

Table 3-7 Summary of Flood Plain Forest Small Mammal Population Study 3-1 Ob

Table 3-8 Summary of Shrew Population Study 3-1 la

Table 3-9 Summary of Small Mammal Population Age Structure 3-12a

Table 3-10 Summary of Small Mammal Reproductive Analyses 3-14a

Table 3-11 Expected and Observed Wildlife Species of the Housatonic River Valley . . 3-16a

Table 3-12 Rare Bird Species Observed in the Housatonic River Valley 3-16b

Table 4-1 Summary of Potential Exposure-Effect Relationships by Measurement Endpoint and by Species 4-8a

ChemRisk* - A Division of McLaren/Hart July 26, 1994 Page 1-1

EVALUATION OF THE TERRESTRIAL ECOSYSTEM OF THE HOUSATONIC RlVER VALLEY

1.0 INTRODUCTION

ChemRisk, the risk assessment division of McLaren/Hart Environmental Engineering, in

collaboration with S.G. Martin & Associates, Inc., was retained by the General Electric Company

(GE) to conduct an evaluation of the health of terrestrial wildlife populations and communities

potentially exposed to polychlorinated biphenyls (PCBs) in soils of the Housatonic River flood plain. McLaren/Hart's ChemRisk Division is one of the largest groups of professionals dedicated

to the use of risk assessment to understand and solve problems associated with exposure to

chemicals released to the environment. More than 20 members of the ChemRisk staff have

advanced training in ecotoxicology, aquatic toxicology, wildlife toxicology, ecology, marine

biology, wetlands and environmental science; the team together has published more than 30 papers

on ecotoxicological risk assessment in peer-reviewed journals and books. Stephen G. Martin

holds a Ph.D. degree in Animal Ecology; he has 30 years of experience in designing, conducting,

and evaluating research programs pertaining to environmental and anthropogenic perturbations to

animals.

PCBs were used as insulating liquids in select transformer applications at the GE facility in

Pittsfield from 1932 until March 1977 (Blasland & Bouck, 1991). Before 1977, inadvertent

releases of these materials from the facility were conveyed to the East Branch of the Housatonic

River. Use of PCBs at the facility was discontinued in 1977.

Flood plain soils between the GE facility and Woods Pond Dam have been investigated for the

presence of PCBs that may have resulted from deposition of river materials on the flood plain

during flooding events (Blasland & Bouck, 1991, 1992a, 1992c, 1993, 1994a). Data from these

sampling efforts indicate that the current composition of PCB Aroclors in Housatonic River flood

plain soils is approximately 99 percent Aroclor 1260, with the remainder being Aroclor 1254.

This ecological evaluation focuses on Aroclor 1260 as the primary stressor of interest

ChemRisk - A Division of McLaren/Hart July 26, 1994 Page 1-2

It has been determined that PCBs in flood plain soils are largely limited to the approximate 10-year

flood plain between the GE facility and Woods Pond Dam (Blasland & Bouck, 1991, 1992a,

1993, 1994a). The great majority of samples collected beyond the approximate 10-year flood plain

contained concentrations less than 1 ppm (Blasland & Bouck, 1991, 1992a, 1993, 1994a). In

those few areas where PCB levels greater than 1 ppm were found outside of the approximate 10

year flood plain, these exceedances were, in general, either the result of inaccuracies in the

topographic mapping or interpretation used in modeling the limits of the approximate 10-year flood

plain in a couple of areas (the flood plain limits in these areas have since been corrected) or else

were found very close to (e.g., within two feet of) the limit of the approximate 10-year flood plain

(see Blasland, Bouck & Lee, 1994b).

In evaluating whether the presence of PCBs in the flood plain soils has potentially stressed the

Housatonic River valley ecosystem, a number of additional factors must be considered as potential

stressors. Physical stressors may include both natural and anthropogenic events, such as extremes

in natural conditions, habitat alteration, direct manipulation of wildlife and resource management

practices. Several natural conditions may stress the Housatonic River valley ecosystem, including

flooding, storms, and extreme temperatures. Flooding may result in drowned individual biota and

destruction of food resources, nests, and cover. Storms, with their associated precipitation,

winds, and extreme temperatures, can stress wildlife through starvation, freezing, drowning, and nest destruction or abandonment. Such extremes in weather are not unusual in Massachusetts.

Alteration of habitat along the Housatonic River is most apparent within the city of Pittsfield and

downstream to the New Lenox Road bridge. Within this reach, residential, commercial and

industrial structures have been constructed, oxbows have been filled, native vegetation has either

been completely removed or replaced with ornamental shrubs and grasses, and the river channel

has been straightened for flood control purposes. In many areas upstream of the New Lenox Road

bridge, these activities have resulted in the complete removal of suitable foraging and nesting

habitats, thereby limiting wildlife inhabitation in these areas. Where habitats have not been entirely

destroyed in the more developed portion of the river, they have been substantially fragmented by

buildings, parking lots, and roads. The roads which dissect the ecosystem of the Housatonic

River valley limit the natural (and necessary) movements of wildlife, a situation analogous to an


island existence (Diamond and May, 1976). Ecosystems that are fragmented, like the upper

Housatonic River valley, create small islands capable of supporting small populations of a limited

number of species (Lovejoy and Oren, 1981).

Downstream of the New Lenox Road-bridge, in the Housatonic Valley Wildlife Management Area

(HVWMA), the physical stressors associated with human development are replaced by hunting,

trapping, and resource management practices. Wildlife species legally hunted in Massachusetts

include crow, turkey, ruffed grouse, pheasant, quail, American woodcock, various waterfowl,

snowshoe hare, cottontail rabbit, opossum, raccoon, fox, coyote, bobcat, gray squirrel, jackrabbit,

black bear, deer, bull frog, green frog, and snapping turtle (MDFW, 1992). Species legally

trapped in Massachusetts include fox, coyote, skunk, opossum, weasel, bobcat, fisher, mink,

raccoon, otter, muskrat, and beaver (MDFW, 1991). Because HVWMA is actively managed to

promote hunting and trapping and since representatives of nearly all levels of the food web may be

legally hunted or trapped, these activities could potentially stress the overall ecosystem, should

overharvesting occur. In addition to these direct effects, resource management practices, such as

mowing and herbicide application, may also stress the ecosystem by changing vegetative structure,

thereby promoting occupancy by non-forest and exotic species, and by limiting cover for feeding,

nesting, and rearing young. The direct effect of mowing on reduced primary productivity may also

lead to increased competition among primary consumers for food resources. Additionally, because mowing inhibits natural succession, mowed areas are effectively maintained at stages of early

successional development. Early successional habitats tend to be dominated by opportunistic

species, which in turn limit species diversity and richness.

This study was designed to evaluate the effects of PCBs on terrestrial wildlife by comparing the

health of wildlife populations within the flood plain downstream of New Lenox Road bridge

(hereafter referred to as the target population) to the health of reference populations that share the

characteristics and stressors of the target population, with the exception of exposure to PCBs.

While there are a number of methodologies for evaluating ecological effects presented in various

guidance documents (EPA, 1989a; EPA, 1989b; EPA, 1990; EPA, 1992), the study designs,

terminologies, and formats recommended by these sources are in many cases inconsistent and in


other cases extremely general, making it difficult to select a single methodology that conforms to all

available guidance and is appropriate to all sites. In designing this study, professional judgment

has been employed in selecting a strategy that is best suited to the specific character of the

Housatonic River flood plain target area.

Two basic types of study methodologies are typically used to assess environmental risks. The first

includes predictive methods, which generally require the application of mathematical models of

food webs to simulate the transfer of a chemical from sediment, soil, or water to lower levels of the

food web and from these lower trophic levels to higher trophic levels. The application of most

food web models, characterized as a "bottom-up" approach, requires substantial extrapolation,

including:

from a species typically used in laboratory experiments (such as the rat or chicken) to a variety of species found in the natural environment;

from observed effects in the laboratory under very controlled conditions to predicted effects in the natural environment;

from individuals to populations; and,

from acute effects (such as the lethal concentration to 50 percent of the population after a single exposure, the LCso) to chronic effects.

There are several other limitations to the bottom-up approach. First, the input data on toxicity that

are required by such models are very limited and are not compiled in any guidance document or

database, let alone one which has received the EPA's approval. As a result, it is necessary to

conduct a comprehensive literature review, compiling a range of toxicity criteria. These studies

and data must then be critically evaluated for applicability to the species and stressors of interest.

In the absence of toxicity criteria handbooks, criteria for selecting input data and the values

themselves will vary among risk assessors.

Second, food web models do not realistically simulate varied food sources for different species and

for individuals within a species. Typically, modelers may input the fraction of the diet assumed to

be derived from a limited number of locations (e.g., chemically exposed vs. unexposed) and/or

food groups (e.g., vegetation, invertebrates, small mammals). Usually, these proportions are


assumed to remain constant over time and to be uniform for all individuals within a species. In

reality, the diet of most wildlife is extremely variable; food availability dictates the relative

proportions of different prey consumed, as well as the size and location of the feeding range.

These factors vary on a daily and seasonal basis. Because models cannot adequately simulate the

dynamics of feeding behavior, considerable uncertainty is introduced with respect to the transfer of

chemicals up the food web.

Third, models cannot account for the movement patterns of free-ranging animals or the individual

behaviors and foraging site preferences. Each of these factors substantially influences dietary

exposure.

Finally, it is difficult, if not impossible, to adequately simulate the effects of both competition and

predation in the natural environment. The fundamentals of population ecology assert that the health

of a community is a function of all interactions within and between species (Begon and Mortimer,

1986), as well as of physical and chemical stressors. The primary interactions within and between

species are competition and predation. While predation is often the focus of food web models,

competition also plays a critical role in the utilization of limited resources, such as food, water, and

breeding territory. As such, competition directly impacts potential exposure to stressors that are

present in these resources. By neglecting competition, food web models may substantially over-or underestimate actual exposure.

The second type of methodology, retrospective assessment, involves field observations and the

collection of community-level data on density, diversity, and reproductive success to determine if

wildlife are adversely affected by the stressor. Because it is possible to focus field monitoring

programs on those species at or near the top of the food web which are likely to face the highest

levels of exposure, this approach may be described as "top-down."

The "top-down" procedure ascertains whether diversity, density, and the reproductive success of

wildlife living in contaminated areas lie within normal ranges as reported in the literature, or

whether they compare favorably to populations inhabiting uncontaminated reference areas. By


monitoring the actual ecosystem potentially at risk, this approach determines whether wildlife are

healthy and whether the ecological system on which they depend is healthy and functional.

Because of the different kinds of uncertainties associated with the "top down" and "bottom up"

approaches, conclusions based on the two approaches may not always agree. In cases where a

divergence exists between conclusions based on the "top down" and "bottom up" approaches,

discrepancies likely reflect the extent of extrapolation necessary to relate the two approaches. For

example, in a typical laboratory toxicity study, cohorts of laboratory mammals (e.g., mice, rats)

would be administered a constant dose of a chemical in the diet, via gavage, intraperitoneally, or

via inhalation over a relatively short period of time (days, weeks, or months). Such conditions are

purposefully controlled in order to allow determination of a dose-response relationship. These

same controlled conditions, however, narrow the applicability of the laboratory study's findings.

In order to realistically apply the findings of this example laboratory study to actual conditions in

the field, variability in the following factors would first need to be accounted for: species,

exposure duration, no/lowest effects levels, genotype, individual/ population/community/eco

system level effect, feeding preference, feeding behavior, grooming behavior, home range,

metabolic rate, contaminant distribution, exposure route, and stress associated with confinement.

Only the first three factors listed are normally accounted for in such extrapolations and, even then,

the basis for the uncertainty factors which allow extrapolation may have little scientific foundation.

In short, if a linkage is not apparent between results of field studies and laboratory studies or

models, it is likely because one or more of these differences in conditions has not or cannot be

accounted for. In the absence of a discernible relationship between field and laboratory studies,

evaluation of a broader range of endpoints can help determine which approach provides the most

accurate conclusions for the site in question.

Given the high level of uncertainty associated with the "bottom-up" method, the "top-down"

approach was selected as the more appropriate study design to be applied in this evaluation of the

terrestrial ecosystem of the Housatonic River flood plain. This assessment focuses on potential

impacts related to exposure to PCBs in materials deposited on the flood plain during flooding

events. Because this investigation focuses on community structure and dynamics, the density,

diversity, and reproductive success of two groups of animals that occupy key roles in the terrestrial


ecosystem (birds and small mammals) were studied. Species density and diversity were evaluated

using standard field censusing techniques, including mark-recapture studies for small mammals

and plot censuses for birds. Reproductive success of small mammals was evaluated by counting

the number of placental scars and/or embryos in female specimens. To study avian reproductive

success, natural nests were monitored for the numbers of eggs laid and young hatched. Data

collected for birds and small mammals inhabiting the flood plain were then compared to data for

reference populations living in areas in which PCBs are not present and to data reported in the

scientific literature.

ChemRisk* - A Division of McLaren/Hart July 26, 1994 Page 2-1

2.0 METHODS

To evaluate the potential effects of Aroclor 1260 on the terrestrial ecosystem of the Housatonic River valley, it was first necessary to:

select the ecosystem to be evaluated, identify types of habitats present in that ecosystem, identify and select indicator species within those habitats, identify potential exposure scenarios, select endpoints to be evaluated, identify and select target areas and either reference areas or literature studies, demonstrate comparability of target areas and reference areas, identify study methodologies, identify statistical and analytical methods with which to compare the ecological health of target areas and reference areas, and

perform the field studies.

The methodologies used in evaluating each of these initial steps are discussed in the following

sections.

2.1 Ecosystem Selected for Evaluation

The reach of the Housatonic River with the highest concentrations of PCBs in flood plain soils is

the 10-year flood plain between the GE facility and Woods Pond dam (Blasland & Bouck, 1992a,

1993, 1994). From the GE facility to the New Lenox Road bridge, habitats are either small or

have been substantially altered and/or fragmented. This would confound any evaluation of

ecological communities within this reach. Between the New Lenox Road bridge and Woods Pond,

there are more widespread and unfragmented wildlife habitats. Although other physical stressors

(such as hunting, trapping, and natural resource management practices) may be present

downstream of the New Lenox Road bridge, these stressors should not confound the assessment,

provided they are also present in reference areas that are evaluated and that species that are hunted

or trapped are not included as indicator species.

Areas of the Housatonic River valley downstream of Woods Pond dam are less suitable for

evaluating the effects of PCBs on ecological receptors for several reasons. First, the PCB

concentrations in both sediments and flood plain soils are substantially lower downstream of

Woods Pond dam than they are upstream, with concentrations detected in flood plain soils


downstream of the dam averaging below 1 ppm (Blasland & Bouck, 1991). Accordingly, the

potential for PCB exposure along this stretch of the river would likewise be substantially lower.

Moreover, the habitat in this portion of the flood plain is less suitable for wildlife than the habitat

between the New Lenox Road bridge and Woods Pond. In virtually all areas downstream of

Woods Pond dam where the flood plain is broad, land use is dominated by agriculture. Regular

plowing, tilling, and harvesting practices on agricultural land strongly affect the natural ecosystem,

rendering most agricultural lands suitable habitat only for opportunistic and tolerant species. In

other areas downstream of Woods Pond dam, the flood plain is so narrow as to be practically

nonexistent; PCBs would not likely be deposited on these steep banks, which are characteristic of

scouring environments.

For these reasons, the present evaluation focuses on the ecosystem located within the 10-year flood

plain of the Housatonic River between the New Lenox Road bridge and Woods Pond dam, as

illustrated in Figure 2-1. The concentrations of PCBs in flood plain soils within this reach range

from below detection to around 100 ppm, as illustrated in Figures 2-2 through 2-5. Given the

elevated concentrations of PCBs in flood plain soils, coupled with the widespread availability of

desirable wildlife habitat along this stretch of the Housatonic River, this study area allows for the

assessment of potential effects under worst-case (maximum) exposure conditions. If adverse

effects are not observed in this ecosystem, then they would not be expected to occur where the

potential for exposure is lower.

The flood plain south of New Lenox Road to Woods Pond dam is relatively wide. Approximately

one-half mile south of New Lenox Road, the flood plain along the east bank of the river is

confined by October Mountain, while the west bank has a relatively flat topography resulting in an

extended flood plain (Blasland & Bouck, 1991). Within this reach, the Housatonic River is

associated with substantial wetland flood plains and backwater areas. Here, the river is slow-

mixing and meandering as it travels through relatively flat areas of local topography, and

deposition of sediment within the backwater areas is pronounced (Stewart Laboratories, 1982).

Because the mesic flood plains between New Lenox Road and Woods Pond dam also provide the

largest intact wildlife habitat upstream of Woods Pond dam, they were targeted for ecological

study.

CtemRisk-A DMston of McLaren/Hart JULY29, 1994 PAGE 2-2A

SEE FIGURES 2-2 THROUGH 2-5 FOR DETAIL mi >

1200' 1200'

APPROXIMATE SCALE

24-00

LIMIT OF APPROXIMATE FLOOD PLAIN

EDGE OF WATER

ROADWA-T OR TRAIL

1 THE LIMIT OF FLOOD PLAIN REPRESENTS THE APPROXIMATE 10-YEAR FLOOD PLAIN

Original includes color coding.

BLASLAND, BOUCK & LEE, INC. ENGINEERS & SCIENTISTS

GENERAL ELECTRIC COMPANY PITTSFIELD, MASSACHUSETTS

MAP OF THE HOUSATONIC RIVER FIGURE FLOOD PLAIN BETWEEN

7/94 54-AK NES LENOX RD. & WOODS POND DAM 1019741R/CHEMRSK/10197G01 DWG

2-1

Ctt*nRtek-A DMaton of McLaren/Hart JULY 29.1994 PAQE2-2B

1988-1989 PARCEL 29-1 SAMPLING LOCATION

PCB CONCENTRATION (PPM DRV WEIGHT) 0-4 DEPTH

PC8 CONCENTRATION (PPM DRY WEIGHT) 4"-8" DEPTH

RESULTS Of DUPLICATE ANALYSIS

FLOOD PLAIN TRANSECT LINE

TRANSECT SAMPLE LOCATION (1990-1992)

TRANSECT SAMPLE LOCATION NAME PCB CONCENTRATION (PPM) 0"-6' DEPTH PCB CONCENTRATION (PPM) 6--12" DEPTH

ROOD PLAIN SIM EVALUATION SAMPLE LOCATION (AUGUST 1992)

DECKER CANOE LAUNCH STM EVALUATION SAMPLE LOCATION (JULY 1993)

SAMPLE IDENTIFICATION

PCB CONCENTRATION (PPM DRV WEIGHT) a'-e' DEPTH SEDIMENT SAMPLING LOCATION (1981-1982) r / SEDIMENT SAMPLING LOCATION (1990-1991)

FLOOD PLAIN COMPOSITE SAMPLING LOCATION (APRIL & MAY 1994)

LIMIT OF APPROXIMATE IDYEAR FLOOD PLAIN

NOTES.

1 THE BASE MAP FEATURES PRESENTED ON THIS FIGURE WERE PHOTOGRAMMETRICALl'i MAPPED FROM APRIL 1990 AERIAL PHOTOGRAPHS (AREA NORTH OF NEW LENOX ROAD) AND FROM APRIL 1983 AERIAL PHOTOGRAPHS (AREA SOUTH OF NEW LENOX ROAD

2 THE LIMIT OF FLOOD PLAIN REPRESENTS THE APPROXIMATE 1O-YEAR FLOOO PLAIN DELINEATION OF 10-YEAR FLOOD PLAIN IS BASED ON HEC-2 HYDRAULIC MODELING PERFORMED BY BLASLAND & BOUCK ENGINEERS P C (1991) AND AVAILABLE TOPOGRAPHIC MAPPING

3 TAX ASSESSORS PARCEL IDENTIFICATION NUMBERS AND BOUNDARY INFORMATION OBTAINED FROM CITl OF PITTSFIELD S TAX ASSESSORS OFFICE AND IS CURRENT THROUGH DECEMBER 31 1991

4 ALL SAMPLE LOCATIONS ARE APPROXIMATE

5 DATA QUALIFIERS REFERENCE NO NOT DETECTED J ESTIMATED VALUE BELOW OUANT1TAT10N LIMIT fSHRUB MEADOW

DECKER CANOE LAUNCH AREA APPROXIMATE SCALE

BLASLAND, BOUCK & LEE, INC ENGINEERS & SCIENTISTS

GENERAL ELECTRIC COMPANY PITTSFIELD MASSACHUSETTS

CONTINUED ON SHEET 2-3

SUMMARY OF RIVER SEDIMENT X 10197G03 DWG AND FLOOD PLAIN SOIL SAMPLING LA ONOFFREF. -MAP_NUM -PROPERTY -ROW GC-OBG 7/94 54- RLP NES

RESULTS & STUDY AREA LOCATIONS 10I9741R/10197GO.'!

ChemR&F-A Division of McLaren/Hart JULY 29, 1994 PAQE 2-2C


SHRUB MEADOW

TARGET ARE

SEDIMENT SAMPLING LOCATION (1981-1982)


FLOOD PLAIN COMPOSITE SAMPLING LOCATION (APRIL In MAY 1994)

FLOOD PLAIN SAMPLING LOCATION (JUNE 1991)

PC9 CONCENTRATION (PPM DRY WEIGHT) 0"-6" DEPTH

NEST LOCATION

FLOOD PLAIN LIMIT OF APPROXIMATE 10 -YR FLOOD PLAIN

FOREST TARGET AREA EDGE OF WATER PAVED ROADWAY

UNPAVED ROADWA1 OR TRAIL

RAILROAD

VEGETATION

THE BASE MAP FEATURES PRESENTED ON THIS FICURF WERE PHOTOGRAMMETRICALLY MAPPED FROM APRIL 1983 AERIAL PHOTOGRAPHS

THE LIMIT OF FLOOD PLAIN REPRESENTS THE APPROXIMATE 10-YEAR FLOOD PLAIN DELINEATION OF 10-YEAR FLOOD PLAIN IS BASED ON HEC-2 HYDRAULIC MODELING PERFORMED B~i BLASLAND & BOUCK ENGINEERS P C (I9S1) AND AVAILABLE TOPOGRAPHIC MAPPING

TAX ASSESSORS PARCEL IDENTIFICATION NUMBERS AND BOUNDARY INFORMATION OBTAINED FROM CITY OF PITT5FIE1D S TAX ASSESSORS OFFICE AND IS CURRENT THROUGH DECEMBER 31 1991


5 DATA QUALIFIERS ND NOT DETECTED J ESTIMATED VALUE BEIOW QUANflTATION LIMIT

APPROXIMATE SCALE


CONTINUED ON SHEET 2-4 GENERAL ELECTRIC COMPANY PITTSFIELD, MASSACHUSETTS

SUMMARY OF RIVER SEDIMENT FIGURE X 10197G04 DWG LA ON-' OFF>REF MAP_NUM -PROPERT1 -ROW GE> 06O 7/94 54 RLP NES

AND FLOOD PLAIN SOIL SAMPLING RESULTS & STUDY AREA LOCATIONS 2-3

1019741R/10197G04DVK:

ChemfVsk'-A DMslon of McLaren/Haft JULY29. 1994 PAGE2-2D


FLOOD PLAIN TRANSECT LINE

TRANSECT SAMPLE LOCATION (1990-1992)

TRANSECT SAMPLE LOCATION NAME PCB CONCENTRATION (PPM) 0"-6" DEPTH PCB CONCENTRATION (PPM) 6"-12" DEPTH PCB CONCENTRATION (PPM) 12"-18" DEPTH PCB CONCENTRATION (PPM) 18"-24" DEPTH



FLOOD PLAIN SAMPLING LOCATION (JUNE 1994)

PCB CONCENTRATION (PPM DRY WEIGHT! 0"-6" DEPTH

NEST LOCATION

LIMIT OF APPROXIMATE 10-YEAR FLOOD PLAIN

EDGE OF WATER

PAVED ROADWAY

UNPAVED ROADWA't OR TRAIL

RAILROAD

VEGETATION

MOTtS

1 THE BASE MAP FEATURES PRESENTED ON THIS FIGURE WERE PHOTOGRAMMETRICALLY MAPPED FROM APRIL 198"* AERIAL PHOTOGRAPHS

? THE LIMIT OF FLOOD PLAIN REPRESENTS THE APPROXIMATE 10-YEAR FLOOD PLAIN DELINEATION OF 10-YEAR FLOOD PLAIN IS BASED ON HEC-2 HYDRAULIC MODELING PERFORMED BY BLASLAND & BOUCK ENGINEERS, PC (1991) AND AVAILABLE TOPOGRAPHIC MAPPING

3 TAX ASSESSORS PARCEL IDENTIFICATION NUMBERS AND BOUNDARY INFORMATION OBTAINED FROM CITY OF PITTSFIELD S TAX ASSESSORS OFFICF AND IS CURRENT THROUGH DECEMBER 31 1991


5 DATA QUALIFIERS ND NOT DETECTED


APPROXIMATE SCALE


GENERAL ELECTRIC COMPANY PITTSFIELD, MASSACHUSETTS

SUMMARY OF RIVER SEDIMENT FIGURE AND FLOOD PLAIN SOIL SAMPLING

RESULTS & STUDY AREA LOCATIONS 2-4 X 10197GOSDWG LA ON-> OFF-.REF- MAP_NUM.'PROPERTY -ROW.GE- OBG> 7/94 54- RLP, NES 1019741R/10197G05 DWG

ChemRlsk^A DMslon of McLaren/Hart JULY29. 1994 PAGE 2-2E

1-3A (008 PPM)

1-36 (1 2 PPM)

1-3C

(029 PPM)

A FLOOD PLAIN STM EVALUATION SAMPLE LOCATION (AUGUST 1992)

1-3A SAMPLE IDENTIFICATION

^0 06 PPM) PCS CONCENTRAT10N-(PPM DRY WEIGHT) 0"-6" DEPTH

SEDIMENT SAMPLING LOCATION IB (1981-1982)

SEDIMENT SAMPLING LOCATION a (1990-1991) FLOOD PLAIN SAMPLING LOCATION (JUNE 1994)

PCB CONCENTRATION (PPM OR) WEIGHT) (46) 0"-6 DEPTH

NEST LOCATION

* LIMIT OF APPROXIMATE 10-YEAR FLOOD PLAIN

EDGE OF WATER

PAVED ROADWAY

UNPAVED ROADWAt OR TRAIL

RAILROAD

VEGETATION

NOTES.

1 THE BASE MAP FEATURES PRESENTED ON THIS FIGURE WERE PHOTOGRAMMETRICALL1 MAPPED FROM APRIL 1983 AERIAL PHOTOGRAPHS

2 THE LIMIT OF FLOOD PLAIN REPRESENTS THE APPROXIMATE 10-YEAR FLOOD PLAIN DELINEATION OF 10-YEAR FLOOD PLAIN IS BASED ON HEC-2 HYDRAULIC MODELING PERFORMED BY BLASLAND * BOUCK ENGINEERS P C (1991) AND AVAILABLE TOPOGRAPHIC MAPPING

3 TAX ASSESSORS PARCEL IDENTIFICATION NUMBERS AND BOUNDARY INFORMATION OBTAINED FROM CITY OF PITTSFIELD'S TAX ASSESSORS OFFICE AND IS CURRENT THROUGH DECEMBER 31 1991

4 AIL SAMPIE LOCATIONS ARE APPROXIMATE

.


200 0 200 4-00

APPROXIMATE SCALE


GENERAL ELECTRIC COMPANY PFTSFIELD, MASSACHUSETTS

SUMMARY OF RIVER SEDIMENT FIGURE AND FLOOD PLAIN SOIL SAMPLING

RESULTS & STUDY AREA LOCATIONS 2-5 X 101Q7G06DWG LON--OFF--REF- -MAP_NUM -PROPERTY.-ROW GE- OBG"* 94 ?4- RLP NES I0174IR/10197G060WG


2.1.1 Characterization of Habitats

Based on Land Use and Property Ownership Maps (Blasland & Bouck, 1992b), National

Wetlands Inventory maps, and field observations, much of the land between New Lenox Road and

Woods Pond dam that is potentially affected by a 10-year flood event is comprised of flood plain

forests, shrub meadows, and cattail marshes.

The Housatonic flood plain forest is dominated by mixed hardwood trees with scattered pine. It is

intermittently flooded and has well developed ground, shrub, and tree strata. Ground cover is

prevalent, consisting mainly of ferns. The shrub stratum, which covers approximately one-third of

the flood plain forest, is relatively diverse and is dominated by arrowood and sugar maple. The

tree stratum is well developed both in terms of density and diversity. The diversity is typical of a

forest controlled by flooding; while many species of trees (balsam poplar, black oak, black cherry,

white and yellow birch, ironwood, etc.) are represented, one species dominates (sugar maple).

The ground, shrub, and tree strata together comprise a diverse community providing high quality

habitat for song birds and small mammals.

Shrub meadows along the Housatonic River between New Lenox Road and Woods Pond dam are

early successional ecosystems dominated by grass-forb-shrub communities. Within the region of

interest, most shrub meadows are actively managed for wildlife and hunting by mowing and other

practices. Vegetation is abundant, even in mowed areas. The ground cover is comprised of

grasses and forbs, interspersed with occasional emergent shrubs.

As their name would suggest, cattail marshes are dominated by cattails, although limited numbers

of red osier dogwood, willow, and silver maple are interspersed among the cattails. Arrowheads,

water hyacinths, and lily pads are generally present in the backwaters of the river along the cattail

marshes. Duck blinds and nest boxes have been established in many of these marsh areas.

Additionally, because the cattail stands are of limited size, are frequendy inundated with water, and

are dominated by a single plant species, they do not support extensive or diverse terrestrial wildlife

populations.


2.1.2 Selection of Indicator Species

Upon completion of a literature review, indicator species were selected based on feeding habits,

territory sizes, densities, trophic levels, and extent of human interference associated with each of

the individual species expected in the ecosystem. While large mammals, raptors, and piscivorous

species were considered in the selection of indicator species, there were a number of reasons why

they were not determined to be optimal indicator species for this evaluation. A complete review of

the rationale behind the selection of target species is provided in Appendix A and summarized in

Table 2-1.

The indicator species selected for evaluation included the Northern short-tailed shrew, white-footed

mouse, Southern red-backed vole, Eastern phoebe, barn swallow, wood thrush, American robin,

yellow warbler, American redstart, rose-breasted grosbeak, and red-winged blackbird.

As shown in Table 2-2, each of the indicator species shares several characteristics which directly

influence their potential for exposure to PCBs in flood plain soils. Specifically, all of the indicator

species have home ranges substantially smaller than the 10-year flood plain, ensuring that the

majority of the area where they forage is within the study area. Second, with few exceptions, the

indicator species are secondary consumers, indicating that exposures are likely to occur through

foodweb transfer, as well as through direct contact and ingestion of soils during grooming.

Potential for exposures through direct contact varies among indicator species; those that nest and forage on or near the ground, such as the small mammals, wood thrush and red-winged blackbird,

clearly have increased potential for exposure through direct contact and inhalation. In contrast,

most of the activities of the American redstart are conducted in the upper canopy, where exposures

are limited to food web transfer as it feeds on flying insects that metamorphosed from larval stages

living in flood plain soil or river sediments.

2.2 Characterization of Exposure Scenarios

The potential exposure routes, frequencies, and timings for the indicator species used in this

ecological evaluation are summarized in Table 2-3. For all species, the spatial scale of their

primary activities is closely related to the spatial scale of PCBs in flood plain soils. That is,

depending upon the species, certain or all activities such as foraging, incubating, preening or

ChemRisk A Division of McLaren/Hart July 26, 1994 Page 2-4a

Table 2-1.

Species Considered Advantages

Large Mammals

White-tailed Range includes the Berkshires Deer Social value (hunting,

aesthetics)

Black Bear Range includes the Berkshires Social value (hunting, aesthetics)

Moose Range includes the Berkshires Social value (aesthetics)

Rationale for Selection of Indicator Species

Selected as an Indicator

Disadvantages Species?

Diet primarily consists of vegetation, so opportunity would NO be limited for exposure through the food web Large feeding territories and home ranges expand beyond the target area, suggesting it would be difficult to distinguish between target and reference populations Limited potential for exposure due to large feeding territories and home ranges Sample sizes would be limited due to low population densities typical of large mammals Preferred habitat is limited within the 10-year flood plain of the Housatonic River valley

Diet primarily consists of vegetation, so opportunity NO would be limited for exposure through the food web Large feeding territories and home ranges expand beyond target area, suggesting it would be difficult to distinguish between target and reference populations Limited potential for exposure due to large feeding territories and home ranges Sample sizes would be limited due to low population densities typical of large mammals Preferred habitat is limited within the 10-year flood plain of the Housatonic River valley

Diet primarily consists of vegetation, so opportunity NO would be limited for exposure through the food web Large feeding territories and home ranges expand beyond the target area, suggesting it would be difficult to distinguish between target and reference populations Limited potential for exposure due to large feeding territories and home ranges Sample sizes would be limited due to low population densities typical of large mammals Preferred habitat is limited within the 10-year flood plain of the Housatonic River valley

Page 1 of 8

ChemRisk - A Division of McLaren/Hart July 26, 1994 Page2-4a

Table 2-1. Rationale for Selection of Indicator Species (cont'd)

Selected as Species

Considered Advantages Disadvantages an Indicator

Species?

Furbearers

Marten Because diet consists of small Current distribution is restricted to north of the St. NO mammals, birds, and insects, opportunity for dietary exposure through food chair transfer is high Home ranges are normally small; therefore individuals are naturally restricted to the reference or target area Easily trapped for study Social value (trapping)

Lawrence River. Therefore, it is unlikely that populations exist in the Berkshires Preferred habitat is upland, characterized by spruce, balsam, and hemlock; in contrast, the habitat of the Housatonic River valley is comprised of bottomlands and cattail marshes

Fisher Social value (trapping) Extirpation of fishers from New England has been reported. Presence in the Berkshires is doubtful

NO

Limited potential for exposure due to large home ranges Large home ranges (12.8 to 24 km in diameter) which expand beyond the target area would make it difficult to distinguish between target and reference populations

Long-tailedWeasel

Diet primarily consists of small mammals, increasing potential

exposure through food web transfer

Social value (trapping)

The grassy and eroded shores of the Housatonic River differfrom the rocky shores preferred by long-tailed weasels. Due to habitat unsuitability, populations of sufficient size for quantitative study are not expected in the Housatonic River valley Limited potential for exposure due to large home ranges

NO

Ermine

Diet consists primarily of small mammals, increasing potential exposure through food web transfer

Social value (trapping)

Preferred habitat (rock piles or other heavy cover close to awatercourse) is not present in the Housatonic River valley. Due to habitat unsuitability, populations of sufficient size for quantitative study are not expected in the Housatonic River valley Distinguishing between reference and target population would be difficult, given ermines' propensity to travel great distances to feed

NO

Page 2 of 8

ChemRisk - A Division of McLaren/Hart July 26, 1994 Page 2-4a



Furbearers (cont'd)

Mink Diet includes fish, frogs, and aquatic insects, increasing opportunity for accumulation through the food web

Considered highly sensitive to PCBs

River Otter Relatively small but stable populations inhabit most New England states

Diet includes fish, increasing opportunity for accumulation through the food web



The mink's solitary lifestyle would make it difficult to NO locate a target population of adequate size to render statistically meaningful results Extensive home ranges expand beyond the target area, suggesting it would be impossible to distinguish between target and reference populations, due to normal low population densities, populations of sufficient size for quantitative study are not expected in the Housatonic River valley Mink are subject to a wide range of stressors (trapping, habitat destruction, and other human disturbances), the effects of which would confound observations of population effects

Active trapping status in MA would confound observations NO of population effects in the field Feed in both contaminated and uncontaminated areas within a large home range; thus, potential exposure is limited Extensive home ranges expanding beyond the study area would make it impossible to distinguish between target and reference populations Sample sizes would be limited due to naturally low populations densities

Page 3 of 8



Selected as Species an Indicator

Considered Advantages Disadvantages Species?

Small Mammals

White- Diet includes insects, increasing Diet also consists of seeds, acoms, nut, fruits, and green YES footed opportunity for accumulation of plants, reducing opportunity for dietary exposure Mouse contaminant through the food

web Commonly found in woodlands

and thickets like those of the flood plain forests along the Housatonic River

Adequate sample sizes; easily studied due to ease of trapping and high population densities

Close contact with soil increases exposure through dermal contact, inhalation, and incidental ingestion

Small home ranges ensure that individuals are naturally restricted to target or reference areas

Well researched species, permitting comparisons with literature reports

Shrew Insectivorous feeding behavior Mark and recapture population studies are not feasible, due to YES Species increases opportunity for extremely rapid metabolism, which causes the animals to

exposure through the food web starve to death within hours of being trapped Commonly found in woodlands

and thickets like those of the flood plain forests along the Housatonic River

Close proximity to soil increases exposure through dermal contact, inhalation, and incidental ingestion

Page 4 of 8

ChemRiskJuly 26, 1994 Page 2-4a

A Division of McLaren/Hart



Species?

YES

NO


Small Mammals (cont'd)

Southern Commonly found in forests Red-backed similar to those in the flood Vole plains along the Housatonic

River Owls, hawks, foxes, bobcats,

mustelids, and raccoons feed on meadow voles; therefore, alterations in vole populations could potentially affect all species that prey on them

Small home ranges naturally restrict individuals to contaminated or uncontaminated areas

Adequate sample sizes easily studied, due to ease of trapping and naturally high population densities

Close contact with soil increases exposure through dermal contact, inhalation, and incidental ingestion

Easily studied concurrently with other small mammals

Avian Species

Belted Piscivorous feeding behavior Kingfisher increases opportunity for

exposure through the food web Social value (aesthetics, bird

watching)

Disadvantages

Diet consists of vegetative material, thus reducing opportunity for dietary exposure

Solitary behavior would make it difficult to locate a target population of adequate size to render statistically meaningful results Woody roots, which are common in the Housatonic study area, impede nest excavation; therefore, belted kingfisher would not breed along the Housatonic River Masses of pondweed and water buttercup (like those found on the reaches of the Housatonic River) are a deterrent to foraging

Page 5 of 8



Species Selected as i Considered Advantages Disadvantages Indicator Spec

Avian Species (cont'd)

Osprey Piscivorous feeding behavior Ospreys are migratory species in the Berkshires. In MA, they NO increases opportunity for only breed near the coast (Veil and Peterson, 1993) exposure through the food web Large feeding ranges may expand far beyond the target area,

Social value (aesthetics, bird suggesting it would be difficult to distinguish between target watching) and reference populations

Clear waters are preferred for foraging over those with extensive emergent and submergent vegetation, like the Housatonic River.

Bald Eagle Piscivorous feeding behavior Does not nest in the region NO increases opportunity for Sample sizes would be limited due to naturally low population exposure through the food web densities Social value (aesthetics, bird Clear waters are preferred for foraging over those with extensive watching) emergent and submergent vegetation, like the Housatonic River

Open canopy and old growth forests, which are not generally present along the Housatonic, are preferred habitat

Human disturbances that are common in the Housatonic River valley may deter bald eagles from inhabiting the region

Studying an endangered species, particularly one known to avoid human disturbance, might disturb the birds to the extent that behavior and reproductive success might be adversely affected

Huge feeding areas make it impossible to differentiate between target and reference populations

Other Birds High trophic level enhances Sample sizes expected to be limited due to naturally low NO of Prey opportunities for exposure population densities

through food chain transfer Large feeding territories and home ranges expand beyond the Social value (aesthetics, bird study area; therefore, extent of exposure to chemicals within the watching) Housatonic flood plain is unknown

Great Blue Piscivorous feeding behavior Great blue herons do not nest in the Housatonic River valley; NO Heron increases opportunity for nesting restricted to more remote areas of the Berkshires (Keefe,

exposure through the food web personal communication, 1993) Inspection of the nests for Large feeding territories that expand beyond the target area reproductive success could be would make it difficult to distinguish between reference and easily accomplished, since the target populations birds nest in dense colonies Open canopies and exposed limbs generally used for nesting are Social value (aesthetics, bird rare along the Housatonic River. Therefore, breeding watching) populations sufficient for a quantitative study are not expected

(and are not present) Human disturbances that are common on the Housatonic River

valley may deter great blue herons from nesting in the region. Therefore, sufficient populations for a quantitative study would be difficult to locate

Page 6 of 8


Table 2-1. Rationale



Other Colonial Nesting Piscivorous

Ring-necked Pheasant

Wood Duck

Mallard, Canada Goose, American Black Duck

Piscivorous feeding behavior increases opportunity for exposure through the food web Inspection of the nests for reproductive success could be easily accomplished, since the birds nest in dense colonies Social value (aesthetics, bird watching)

Adequate sample sizes could be easily obtained due to naturally high population densities Small territory sizes naturally restrict individuals to either reference or target area Social value (hunting)

Do not travel far from waterbodies for feeding; thus potential for exposure via incidental ingestion and dermal contact is increased Social value (hunting)

Commonly breed in marshes along Housatonic River Social value (hunting)

for Selection of Indicator Species (cont'd)



According to maps prepared by Veil and Peterson (1993) and NO field observations, very few colonial nesting birds breed in the Berkshires

Populations are actively managed through hunting and NO restocking. Therefore, the effects being studies may be masked or exaggerated by the management practices According to MA atlas (Veit and Petersen, 1993), there are few breeding pairs in western MA. It would be difficult to locate a breeding population of adequate size

Diet is largely herbivorous, limiting potential for exposure NO via food web transfer Habitat in the target area does not provide sufficient natural nesting cavities; therefore, a substantial breeding wood duck population could not be supported naturally The populations are actively managed through habitat management and hunting; therefore, it would be impossible to distinguish population effects potentially caused by PCBs from those associated with hunting and poor natural nesting opportunities.

Forage over wide areas, traveling to upland meadows, NO farmlands, and parks; therefore, exposure to PCBs would be low Diet is entirely herbivorous, limiting potential for exposure via food web transfer Mallards and American black duck populations are hunted. Therefore, it would be impossible to distinguish population effects potentially caused by PCBs from those associated with hunting

Page 7 of 8

ChemRisk A Division of McLaren/Hart July 26, 1994 Page 2-4a


Selected as Species an Indicator

Considered Advantages Disadvantages Species?


Insectivo- Insectivorous feeding behavior Passerines occupy middle trophic levels. Organisms higher YES rous increases opportunity for on the food web may provide better indications of the effects Passerines exposure through the food web of PCBs on the ecosystem if they could be studied in

Small home ranges and feeding sufficient numbers territories are within the target area, making it easy to distinguish between target and reference populations

Adequate sample sizes are easily monitored, due to high population densities

Breeding populations inhabit the Housatonic River valley

Social value (aesthetics, bird watching)

Note: All sources of information are detailed in Appendix A.

Page 8 of 8

Indicator Species

Small Mammals White-footed mouse

Masked shrew

Northern short-tailed shrew

Southern red-backed vole

Preferred Habitat

Interiors and edges of deciduous, mixed, and coniferous forestsb

Damp deciduous and coniferous woodlands

with grasses, rocks, logs or stumps15

Open habitats, such as banks of streams and meadows*5

Cool moist deciduous. mixed, or coniferous forests among mossy rocks, logs, or tree rootsb

^ f ol^-f*pI

> 5 i 3

Table 2-2. Ecosystem Characterization o

Foraging Migratory Territory/Home Nest Height Height

Preferred Food Reproductive Cycle Timing

Cycle Timing in Massachusetts8

Range Size (ha)

(m above ground)

(m above ground)

Seeds, acorns, nuts, Breed in late February to nm 0.06 - 0.22 for adult 0-2e of fruits, and tender green November15 malesb

plantsb Young born March to 0.02 - 0.15 for adult December15 femalesb

Litters per year not specified15

Insects, worms, Breed in late April to late 0.04b O15

spiders, snails, and September or October15

slugs15 Young born in late April to September or October15

Up to 3 litters per year15

Insects, plants, worms Breed March to September15 nm 0.2-0.5lb Oc Ob

snails, and small Young born April to vertebrates15 September15

2 to 3 litters per year15

Mainly green Breed from mid -January to nm 0.10-1.44b 0 d3 vegetation15 late November15

Page 1 of 3

Table 2-2. Ecosytem Characterization (continued)

Preferred Habitat

Birds American redstart

American robin

Barn swallow

Eastern phoebe

Breeds in orchards, saplings bordering pastures, second-growth deciduous woodlands; in shade trees and second-growth maples; also in willow and alder thickets bordering ponds and streams13

Breed in open woodlands, clearings, fields, orchards, and woodland edgesb

Breed on rural farmlands13

Breed in woodlands cliffs, ravines, agricultural and suburban areas, often near streams'3

Preferred Food

Insects, such ascaterpillars, bugs, flies, moths, small grasshoppers, beetles, and wasps'3

Wild and cultivated fruits, insects, and earthworms'3

(60% vegetable matter and 40% animal)b

Flying insects and occasionally fruitb

Flying insects and occasionally small fruitb

Reproductive Cycle Timing

Egg dates are May 21 to June 21d

Incubation period is 12 to 14 daysb

1 brood per year13

Egg dates are April 12-25 to July 2-3d

Incubation period is 1 1 to 14 days'3

2 broods per year*3

Egg dates are May 1 1 to August 3b

Incubation period is 15 days'3

1 or 2 broods per year*3

Egg dates are April 27 to August 15d

Incubation period is 15 to 17 days'3

2 broods per year13

Migratory Cycle Timing

in Massachusettsa

Arrive mid-May1'

Leave late August and September*1

Arrivemid-April*1

Leave late October*1

Arrivemid-April*1

Leave late September to early October*1

Arrive earlyMarchd

Leave late September to early October"1

Territory/Home Range

Size (ha)

0.1-0.4b

0.1-0.3b

Restricted to nest siteb

0.3-1.45 per pair*3

Foraging Nest Height Height

(m above (m above ground) ground)

1.2-9.1b 1.5-15.2b

1.5 4.5, 0-3e

up to 21.3b

1.5-15.2b 1.5- 16e

0.8 to 6.1b 0.8-76

Chem

Risk

A D

ivision of McL

aren/E

uly 26, 1994 'age 2-4b

Page 2 of 3

http:0.3-1.45http:0.1-0.3bhttp:0.1-0.4b

IIP

Table 2-2. Ecosytem Characterization (continued)

Preferred Habitat

Red-winged blackbird

Rose-breasted grosbeak

Wood thrush

Yellow warbler

Preferred Food

Breed in marshes, Insects, weed seeds, swamps, wet meadows and grainb

ponds, dry fields. Prefer wetlands with extensive growth of cattails, bulrushes, sedges, and reedb

Breed on the edges of Insects and spiders moist deciduous (50%) , seeds, and second-growth woods, fruits'' in thickets, suburban

trees, and old orchards, as well as wooded borders

of swamps and streams'5

Breed in lowland Insects (62%) and deciduous or mixed fruits (38%)b

forests; shady, cool, mature upland forests,

often near a swamp, pond, stream, or lake; require abundant under growth*5

Breed in farmlands, Insects, caterpillars, orchards, roadsides, and cankerworms, beetles, along streams and weevils, plant lice, lakesb and grasshoppers

(94% animal, 6%

vegetable)*3

Reproductive Cycle Timing

Egg dates are May 10 to July 18C


2 to 3 broods per year*1

Egg dates are May 23 to July 15d


1 or 2 broods per yearb

Egg dates are May 25 to June 26d


2 broods per year15

Egg dates are May 20 to June 2Qd

Incubation period is 10 to 11 daysb

1 brood per year13

Migratory

Cycle Timing

in Massachusetts3

Arrive midto late Marchd

Leave late October*1

Arrive

mid to late

Mayd

Leave September"1

Arrive late April

early Mayd

Leave late August and

September4

Arrive late Aprild

Leave late July and early August"1

Territory/Home Range

Size (ha)

0.02 0.5b

NA

- 0.6-2.8b

NA

Nest Height(m aboveground)

0-4.3, typicallyless than 1.8b

1.8-7.9b

1.5-15.2,typically 1.5-3.7b

0.6-4.6,typically 0.9 - 2.4b

Division of M

Foraging Height

(m above ground)

FOb i e*

0-30+b

0-2b

1.2-12.2b

0.9-2.4b

a. nm = non-migratory b. DeGraaf and Rudis, 1986 c. Godin, 1977 d. Veil and Peterson, 1993 e. Based on best estimate Page 3 of 3 NA = not available

http:0.9-2.4bhttp:1.2-12.2bhttp:1.5-3.7bhttp:1.8-7.9bhttp:0.6-2.8b

ChemRisk - A Division of McLaren/Hart July 26,1994 Page 2-4c

Table 2-3. Exposure Analysis Summary Approximate %

Activities of Day Potential Exposure during which Associated Timing of

Indicator Species Routes8 with Exposure Exposure is Possibleb Exposure Small Mammals Northern short-tailed FWT>II>IN/DC Feeding, foraging, burrowing, 100% FWT, II: year-round

shrew grooming, and parental carec DC, IN: April to November

Masked shrew FWT>II>IN/DC Feeding, foraging, burrowing, 100% FWT, II: year-round grooming, and parental care DC, IN:

April to November

White-footed mouse H>IN/DCFWT Feeding, foraging, burrowing, 50% FWT, II: year-round grooming, and parental care DC, IN: April to November

Southern red-backed II>IN/DCFWT Feeding, foraging, burrowing, 50% FWT, II: year-round vole grooming, and parental care DC, IN: April to November

Birds American redstart FWTII Feeding, foraging, and preening 58% FWT, II: mid-May to late

August or September

American robin FWT>II>IN/DC Feeding, foraging, nest building, 55% FWT, II, IN, DC: ground gleaning, and preening mid-April to late October

Barn swallow FWT>II>IN/DC Feeding and nest building 55% FWT: mid-April to late September or early October II, IN, DC: mid-to late April

Eastern phoebe FWT>II>IN/DC Feeding and nest building 55% FWT: early March to late September II, IN, DC: March

Red-winged FWT>n>IN/DC Feeding, foraging, ground 55% FWT, II, IN, DC:

blackbirdd gleaning, and preening mid-to late March to late October

Rose-breasted FWT>II>IN/DC Feeding, foraging, gleaning, 58% FWT, n, IN, DC: grosbeak and preening mid-to late May to September

Wood thrush FWT>II>IN/DC Feeding, foraging, ground 58% FWT, II, IN, DC: gleaning, and preening late April-early May to late

August-September

Yellow warbler FWT>II Feeding, foraging, and branch 55% FWT, II: late April to gleaning late July or early August

For all species, primary potential stressor is assumed to be PCBs and medium of interest is floodplain soil, except as noted a. Exposure routes denoted, in order of importance, as foodweb transfer (FWT), dermal contact (DC), incidental ingestion (II), and inhalation (IN) b. Approximate percent of day during which exposure is possible was calculated based on the following assumptions:

daylight averages approximately 14 hours in summer (58% of the day) daylight averages approximately 13 hours when including spring, summer, and/or early fall (55% of the day) daylight averages approximately 12 hours when including spring, summer, and late fall (50% of the day)

c. Parental care involves adult organisms feeding, incubating, and cleaning their offspring d. Red-winged blackbird may contact floodplain soil, sediment, and surface water


grooming, and sleeping occur in close contact with flood plain soils containing PCBs.

Additionally, the relatively small home ranges of all indicator species limit the activities of the

individuals studied to within the 10-year flood plain.

The temporal scale of the presence of PCBs coincides closely with both the life and reproductive

cycles of these animals. While PCBs are assumed present in the flood plain soils year-round,

contact is substantially limited when soils are frozen or covered with snow, as in winter. Exposure

is also limited during the winter months due to the behavior of the indicator species (e.g, migration

of songbirds).

The following exposure profiles describe the potential for exposure of small mammals and

songbirds (passerines) to PCBs in flood plain soils. Potential routes of exposure to PCBs for

small mammal and passerines include: (1) food web transfer via ingestion of organisms that

bioaccumulate PCBs from soil; (2) incidental ingestion of soil particles contaminated with PCBs;

(3) inhalation of volatilized PCBs (expected to be a very minor pathway); and (4) dermal

absorption via contact with exposed body surfaces. The activities associated with each pathway,

the relative importance of each pathway, and the timing of exposures are summarized. Factors

that affect the rates of uptake associated with each pathway, including duration and frequency of

exposure, relative area of exposed body surfaces, and relative absorption at point of contact, are

also discussed.

2.2.1 Small Mammal Exposure Profile

Potential exposure of small mammals to PCBs may occur during a variety of daily activities, such

as feeding, foraging, burrowing, grooming, nest building, and parental care (e.g., nursing,

feeding, grooming). Factors that affect the magnitude of a small mammal's exposure over a

lifetime include: food habits (insectivorous vs. herbivorous); winter status (hibernating vs. non-

hibernating); and duration of daily activity (nocturnal vs. diurnal). Although some mammals

hibernate in the winter, shrews, voles, and white-footed mice are active all year (Godin, 1977) so

that exposure frequency may be as high as twelve months per year for some activities. However,

in western Massachusetts, the ground is normally frozen between November and April, thus

limiting the potential for exposure during this period.

ChemRisk - A Division of McLaren/Hart July 26,1994 Page 2-6

Because shrews are expected to experience relatively high frequency of contact and exposure point

concentrations when they feed on insects, it is likely that the food web transfer largely determines

potential exposures for them. Incidental ingestion is likely the second most important pathway for

shrews because they groom frequently and are in close contact with soil as they burrow and travel.

Although shrews may inhale PCBs, exposures resulting from this route are expected to be

insignificant. Exposure through dermal contact should also be relatively low since their fur should

substantially impede direct contact with soil and dermal absorption.

For voles and mice, exposure to PCBs via incidental ingestion may be greater than exposure via

food web transfer, since a large portion of their diet is vegetation. Uptake of PCBs by plants has

been shown by several researchers to be negligible (Babish et al., 1979; Chou et al., 1978; Iwata

and Gunther, 1976; Miyazaki et al., 1975; Fries and Marrow, 1981; O'Connor et al., 1990; Davis

et al., 1981; Strek et al., 1981; Sawhney and Hankin, 1985). During the winter, when mice and

voles feed to a greater extent on insect larvae and earthworms, food web transfer may become a

more important route of exposure. During the rest of the year, ingestion of particulate-bound

PCBs while feeding on vegetation, foraging in leaf litter, and grooming is likely to be the primary

route of potential exposure to PCBs. As with shrews, inhalation and dermal contact are likely

minor contributors to overall exposure.

2.2.2 Song Bird Exposure Profile

Song birds have the greatest potential for PCB exposure from flood plain soils during feeding,

foraging, nest building, roosting, and preening. Factors that determine the magnitude of exposure

over a lifetime include food habits (herbivorous vs. insectivorous), nesting and feeding locations

(ground vs. canopy), and exposure duration. Throughout their breeding season in Massachusetts

(March to October), birds may potentially be exposed to PCBs in flood plain soils during daylight

hours when they are active. Birds are active from just before dawn to dusk (Brooke and Birkhead,

1991).

The potential magnitude of exposure is largely determined by food web transfer for all passerines

studied in this assessment The primary source of uptake for insectivorous birds are the organisms

on which they feed that bioaccumulate PCBs. Incidental ingestion, as it occurs during foraging,

feeding, preening, and nest building, is thought to be the second most significant exposure


pathway for these birds. Birds that feed and/or nest on the ground (e.g. American robin, red-

winged blackbird, rose-breasted grosbeak, and wood thrush) likely have higher exposure levels

via incidental ingestion than do those that nest and/or feed above ground (e.g. American redstart,

barn swallow, Eastern Phoebe, and yellow warbler). Birds, such as American robin, barn

swallow and Eastern phoebe, that use mud to build nests, may also have increased exposure via

incidental ingestion of sediment

Although inhalation and dermal contact may occur while birds forage, build nests, or roost on the

ground, the inhalation pathway is expected to be less significant than food web transfer and

incidental ingestion for several reasons. For American redstarts and yellow warblers, exposure via

inhalation is assumed to be negligible because they feed, forage, and nest in the canopy, and

because concentrations in the ambient air are expected to be very low relative to concentrations in

soil or in food sources. Exposure via dermal contact should also be low, because adult birds are

covered with feathers and there is little opportunity for contact of contaminated soil with exposed

skin. While the feet and legs may contact flood plain soil, they are covered with keratinized scales

that are relatively impermeable (Welty, 1975).

2.3 Selection of Endpoints

The assessment endpoints selected for evaluation in this study included:

absence of species or taxonomic family or order normally expected to be present in a particular habitat;

reduction of a population or subpopulation due to the stressor of interest; adverse change in the structure of a community; and bioaccumulation that results in an adverse effect.

In order to evaluate these assessment endpoints, a number of field investigations were undertaken

in an effort to evaluate the following measurement endpoints:

diversity of avian species in the flood plain forest; density of avian populations in the flood plain forest; reproductive success of avian populations in all habitats; small mammal population structure in the flood plain forest and shrub meadow; age structure of small mammal populations in the shrub meadow; and reproductive success of small mammals in the shrub meadow and flood plain forest.


2.4 Selection of Study Areas

In order to evaluate the effects of the exposure scenarios, it was first necessary to identify

appropriate target areas within the potentially affected area, as well as appropriate points of

comparison, or reference areas. While the identification of target sites within the contaminated area

was relatively straightforward, it was considerably more difficult to locate areas outside of the contaminated area that could serve as points of reference for observations made with respect to

ecosystem health. Potential reference sites were evaluated by studying National Wetlands

Inventory maps, U.S. Geological Survey topographic maps, and aerial photographs, as well as

through field reconnaissance via helicopter, automobile, foot, and canoe, and through consultation

with personnel at the Western District of the Commonwealth of Massachusetts Division of Fish

and Wildlife.

Specific study areas were defined for each measurement endpoint except avian reproductive

success. Nests that were monitored for this endpoint were differentiated by their location within or

outside of the 10-year flood plain, rather than by localized study area or habitat type. For example,

target nests were typically found along the river banks, under the New Lenox Road bridge, or in

the cattail stands in the river. Reference nests were located well outside of the 10-year flood plain,

including along October Mountain Road, in the reference shrub meadow, and in the Crane Farm

barn in Dawson. Feeding preferences and territory sizes of individual species monitored were

evaluated in order to verify that reference birds would not be expected to visit the target area and vice versa.

In addition, data from the literature (Ehrlich et al., 1988) on normal clutch sizes for each avian

indicator species were also compared to observations of target nests. The target and reference

areas used for all measurement endpoints other than avian reproductive success are described

below by habitat type.

2.4.1 Flood Plain Forest Target Areas

The flood plain forest target area is located south of the New Lenox Road bridge in an area of the

flood plain forest accessible from the Lenox Hunt Club (Figure 2-3). The area is 5.85 hectare in

size and homogenous in habitat. Its north, south, east, and west coordinates are: 509527.383N;


508486.377N; 128973.445E; and 127857.700E, respectively. This target area was selected from

among several other tracts of flood plain forest for several reasons. This site is the largest intact,

undisturbed flood plain forest between New Lenox Road bridge and Woods Pond dam, the reach

of the Housatonic River with both high concentrations of PCBs and suitable wildlife habitat. Other

forested areas within this reach of the river are smaller, have a greater proportion of edge habitat,

and are less accessible than the tract selected as a target area. Furthermore, potential exposure of

wildlife to PCBs at the locality selected as a target area appeared greater than at other candidate

sites, based on general patterns of river sediment and flood plain soil analytical data available prior

to the study area selection and on visual evidence of flooding.

After a great deal of investigation of the area within a 50 mile (or greater) radius of Pittsfield, it was

determined that suitable reference sites were not available for the flood plain forest. The absence of

a suitable reference site is in part a reflection of the target area's location within a HVWMA. This

area differs substantially from land uses of surrounding areas, where residential and agricultural

land uses predominate. In most locations outside of HVWMA, human development, agricultural

activity, and industrialization have drastically impacted the land, rendering it unsuitable for

comparison to the target site. In such areas it would not be possible to distinguish between those

human influences either unrelated to or related to historic PCB releases. While the Housatonic

River upstream of Pittsfield, tributaries to the Housatonic River, and other river valleys (including

the Hoosic and the Konkapot River valleys) were all considered for use as reference sites, no areas

of comparable size, land use, or habitat type were located close enough to the target site to allow simultaneous studies to be conducted. Several candidate reference locations are noted and reasons

for their exclusion are summarized in Table 2-4.

Because an adequate reference flood plain forest could not be located, a comprehensive literature

search was conducted in an effort to identify a suitable reference study for comparison to the avian

population study. Because passerines are highly sensitive to subtle variations in habitat as they

establish breeding territories, the most important criteria for selecting reference studies were habitat

type (i.e., flood plain forest), habitat quality (e.g., forest maturity, isolation from human influence,

size), and habitat structure (e.g., flooding regime, development of strata, canopy cover, dominance

and abundance of plant species). A broad array of sources was searched, including reports of state

and federal agencies and nongovernmental organizations, Master's and Doctoral dissertations, and

scientific journals.

*05 ITable 2-4. Candidate Reference Areas and Rationale for Exclusion

Location of Candidate

Peru State Wildlife Management Area, Peru

Woodlands west of railroad tracks and treatment site, Lenox

Middlefield Slate Forest, Middlefield

Hinsdale Flats State Wildlife Management Area, Hinsdale

October Mountain State Forest

Konkapot River Valley, Clayton

Konkapot River Valley, Hartsville

Hoosic River Valley, Adams

American Legion Park, Dalton

Description

Woodlands adjacent to wetlands between North Road and Mongue Road; access via FraryRoad

Limited flood plain forest bordered by railroad tracks and transmission lines

Wetlands W of Middlefield Road

E of Rt 8 and S of Middlefield Road; access via trail just W of Fassell Road intersection

Wetland SW of Ashley Brook and Ashley Lake, Washington, MA

On CT, MA border

Immediately S of Lake Buell

EofMt. Greylock

Wooded private property E of American Legion Park

Rationale for Exclusion as Reference Area for Avian or Small Mammal Census

Habitat is structurally different from target site as a result of infrequent flooding and higher elevation (588 m)a

Patches of flood plain forest are fragmented and very limited in size; forest very close to (and in some places, within) 10-year flood plain

Elevation greater than treatment (504 m) with poor access; would require extreme effort to access area; habitat is structurally different from target site

Structurally different from and higher elevation (442 m) than target site; understory very developed and affected by calcareous geology and soils

Elevation higher than target site (588 m); abundant spruce; habitat structurally different from target site

River is much smaller than Housatonic; steep valleys preclude extensive flood plain forest development

River is much smaller than Housatonic; steep valleys preclude extensive flood plain forest development

Steep valleys preclude extensive flood plain forest development

Fragmented and small in size

a. Elevation of treatment flood plain forest target site is 294 m.


Based on the criteria described above, two series of breeding bird censuses were selected as the

most suitable reference studies. These are breeding bird plot censuses that were conducted since

1981, as part of the Breeding Bird Census in a flood plain forest in Maryland (Criswell and

Gauthey, 1983; Van Velzen and Van Velzen, 1985, 1986, 1987, 1988; Gauthey 1984, 1989,

1990, 1991, 1992) and in a flood plain forest in North Carolina (Crotteau et al., 1978, 1979;

Christensen et al., 1980,1982; Hall et al., 1984; Van Velzen and Van Velzen, 1985; Hall, 1990;

Mueller and Hall, 1991; Mueller and Mueller, 1992; Mueller, 1993). The annual Breeding Bird

Census is a nationwide effort jointly sponsored by the Association of Field Ornithologists and

Cornell Laboratory of Ornithology. It includes detailed information on the habitats of the

individual study plots, which facilitates comparisons with outside databases. The Breeding Bird

Census shares objectives and methodologies virtually identical to those of the avian census

conducted at the Housatonic flood plain forest. No comparable reference sites closer to the

Housatonic River could be identified in the scientific literature. Although it would clearly be

desirable to use reference sites located closer to the target area, these two series of censuses were

determined to be appropriate reference studies because they are very similar to the target area with

respect to habitat type, quality, and structure. A detailed comparison of the target area and

reference area habitats is presented in Appendix B.

The scientific literature was also searched for reference studies for observations of white-footed

mice and Southern red-backed vole populations in the flood plain forest. A 27-month study

conducted by Batzli (1977) in Illinois on white-footed mice and a 3-year study by Miller and Getz

(1977) in Connecticut on white-footed mice and Southern red-backed voles were chosen as

reference studies for the small mammal studies. These studies had objectives similar to this

analysis, adequate interpretations of findings for comparisons of results, and were conducted in

flood plain forest habitats similar to the Housatonic River Valley flood plain.

2.4.2 Shrub Meadow Study Areas

Suitable shrub meadow target and reference areas were both located south of the New Lenox Road

bridge at sites accessible from the Lenox Hunt Club (Figures 2-2 and 2-3). The shrub meadow

target area is located within the approximate 10-year flood plain, just north of the flood plain forest

target area. The reference shrub meadow is located outside of the 10-year flood plain, directly

northeast of the Lenox Hunt Club and east of the railroad tracks. The north, south, east and west


coordinates of the target shrub meadow are: 509691.593N; 509481.927N; 129057.165E; and

128543.098E, respectively. The north, south, east, and west coordinates of the reference shrub meadow are: 511313.026N; 510884.591N; 128170.279E; and 127999.333E, respectively.

2.4.3 Characterization of PCBs in Flood Plain Soils and River Sediments

To assess the concentrations of PCBs to which the receptors in the areas under study could be

exposed, the results of prior sampling in and near those areas were reviewed. This evaluation

included not only the PCB concentrations detected in flood plain soils in and near the areas under

study, but also the PCB concentrations in nearby river sediments. PCBs in river sediments affect

the total exposures of insectivorous small mammals and birds via foodweb transfer, since a portion

of the diet of these organisms is comprised of insects and insect larvae that mature in river water

and sediment. Additionally, because

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