Sediment Quantity and Quality in

Three Impoundments in Massachusetts

By MARC J. ZIMMERMAN and ROBERT F. BREAULT

Water-Resources Investigations Report 03-4013

In cooperation with the

MASSACHUSETTS DEPARTMENT OF ENVIRONMENTAL PROTECTION, 

MASSACHUSETTS DEPARTMENT OF FISHERIES, WILDLIFE, AND 

ENVIRONMENTAL LAW ENFORCEMENT RIVER RESTORE PROGRAM, 

MASSACHUSETTS EXECUTIVE OFFICE OF ENVIRONMENTAL AFFAIRS’ 

WATERSHED INITIATIVE, and the MASSACHUSETTS DEPARTMENT OF 

ENVIRONMENTAL MANAGEMENT

Northborough, Massachusetts

2003
For additional information write to:

Chief, Massachusetts–Rhode Island District

U.S. Geological Survey

10 Bearfoot Road

Northborough, Massachusetts 01532

or visit our Web site at

http://ma.water.usgs.gov

This project was financed partially with Federal funds from the U.S. Environmental Protection Agency 

(USEPA) to the Massachusetts Department of Environmental Protection (the Department) under 

Section 104(b)3 of the Clean Water Act. The contents do not necessarily reflect the views and policies 

of the USEPA or of the Department, nor does the mention of trade names or commercial products 

constitute endorsement or recommendation for use by the U.S. Government.

This project also received funding from the Massachusetts Department of Fisheries, Wildlife, and 

Environmental Law Enforcement’s River Restore Program, the Executive Office of Environmental 

Affairs’ Massachusetts Watershed Initiative, and the Massachusetts Department of Environmental 

Management.

Copies of this report can be purchased from:

U.S. Geological Survey

Branch of Information Services

Box 25286

Denver, CO 80225-0286

U.S. DEPARTMENT OF THE INTERIOR

GALE A. NORTON, Secretary

U.S. GEOLOGICAL SURVEY

Charles G. Groat, Director
Contents III

CONTENTS

Abstract ................................................................................................................................................................ 1

Introduction .......................................................................................................................................................... 2

Previous Studies and Historical Information .............................................................................................. 2

Purpose and Scope ...................................................................................................................................... 3

Acknowledgments....................................................................................................................................... 5

Methods of Assessment and Analysis.................................................................................................................. 5

Bathymetric Mapping.................................................................................................................................. 6

Sediment Mapping ...................................................................................................................................... 6

Sediment-Sample Collection....................................................................................................................... 6

Data Representativeness and Number of Samples............................................................................. 6

Collecting and Processing Samples ................................................................................................... 8

Laboratory Analyses ................................................................................................................................... 9

Potential for Adverse Biological Effects..................................................................................................... 11

Quality Assurance and Quality Control ...................................................................................................... 12

Analytical Results for Perryville.......................................................................................................................... 14

Bathymetric Mapping.................................................................................................................................. 14

Sediment Volume and Thickness................................................................................................................ 14

Sediment Cores ........................................................................................................................................... 17

Particle-Size Analysis ................................................................................................................................. 17

Chemical Analyses...................................................................................................................................... 17

Organic Compounds .......................................................................................................................... 17

Trace Metals....................................................................................................................................... 20

Analytical Results for Silk Mill and Ballou......................................................................................................... 22

Bathymetric Mapping.................................................................................................................................. 22

Sediment Volume and Coring..................................................................................................................... 24

Particle-Size Distribution............................................................................................................................ 24

Chemical Analyses...................................................................................................................................... 24

Application of Guidelines for Assessing Sediment Chemistry............................................................................ 24

Number of Samples Analyzed .................................................................................................................... 25

Contaminant Concentrations and Exceedance Guidelines.......................................................................... 25

Contaminants and Their Potential Toxicity ................................................................................................ 27

Summary and Conclusions................................................................................................................................... 29

References Cited .................................................................................................................................................. 30

Appendix: Complete Listing of Elemental Analyses Performed by XRAL Laboratories, Inc............................ 31
IV Figures

FIGURES

Figure 1. Map showing locations of the Perryville Dam on the French River in Webster, 

Massachusetts, and the Silk Mill and Ballou Dams on Yokum Brook in Becket, 

Massachusetts .................................................................................................................................... 3

Figure 2. Photograph of Perryville Dam, Webster............................................................................................ 4

Figure 3. Photograph of Silk Mill Dam, Becket ............................................................................................... 4

Figure 4. Photograph of Ballou Dam, Becket ................................................................................................... 5

Figure 5. Photograph showing ground-penetrating radar being used to collect field data................................ 7

Figure 6. Photograph of examination of a sediment core collected with a Livingstone corer from 

Perryville Pond in Webster ................................................................................................................ 8

Figure 7. Photograph of centrally located island formed by sediment deposits and covered with 

purple loosestrife (Lythrum salicaria) in Perryville Pond in Webster............................................... 9

Figure 8. Graph showing sediment-core lengths, depths below sediment surface, and samplesection identifiers............................................................................................................................... 10

Figure 9. Map showing bathymetric and bottom-sediment thickness map of Perryville Pond in 

Webster .............................................................................................................................................. 16

Figure 10. Map showing bathymetric and bottom-sediment thickness map of Silk Mill impoundment, 

Becket ................................................................................................................................................ 22

Figure 11. Map showing bathymetric and bottom-sediment thickness map of Ballou impoundment, 

Becket ................................................................................................................................................ 23
Tables V

TABLES

Table 1. Comparison of families of compounds that may be detected by the ELISA method 

used in this study in the U.S. Geological Survey Massachusetts–Rhode Island District 

laboratory and other methods used by Columbia Analytical Services, Inc., laboratory.................... 13

Table 2. Comparison of quality-control replicate samples analyzed by the ELISA method for 

organic compounds ............................................................................................................................ 14

Table 3. Comparison of ELISA results with duplicate quality-control sample results from 

Columbia Analytical Sevices, Inc...................................................................................................... 14

Table 4. Comparison of concentrations of selected metals in duplicate quality-control samples 

analyzed by XRAL Laboratories, Inc. ............................................................................................... 15

Table 5. U.S. Geological Survey sample identifiers and shortened identifiers for maps used in 

this study ............................................................................................................................................ 15

Table 6. Sediment particle-size distribution for samples collected from Perryville Pond, Webster,

and from Silk Mill and Ballou impoundments, Becket, Massachusetts, July 2000 .......................... 18

Table 7. Results of ELISA analyses of organic sediment constituents in samples collected from 

Perryville Pond and from Silk Mill and Ballou impoundments ........................................................ 19

Table 8. Selected constituent concentrations in sediment samples from vegetated and open-water 

zones of Perryville Pond, 1984 .......................................................................................................... 20

Table 9. Concentrations of selected metals analyzed by XRAL Laboratories ................................................ 21

Table 10. Number of samples needed to define the mean concentrations of analytes within 

25 percent and with 90 percent confidence for Perryville Pond and the two Becket 

impoundments (Silk Mill and Ballou combined) .............................................................................. 25

Table 11. Sediment-quality guidelines for freshwater benthic organisms and human-contact data.................. 26

Table 12. Incidence of toxicity based on Probable Effect Concentration (PEC) quotients in samples 

from Perryville Pond, Silk Mill and Ballou impoundments .............................................................. 28
VI Conversion Factors, Acronyms and Abbreviations

CONVERSION FACTORS, ACRONYMS AND ABBREVIATIONS

CONVERSION FACTORS

Multiply By To Obtain

cubic foot (ft3) 0.02832 cubic meter

foot (ft) 0.3048 meter

gram (g) 0.0353 ounce, avoirdupois

inch (in) 25.4 millimeter

inch (in) 2.54 centimeter

inch (in) 0.0254 meter

microgram (μg) 3.53 x 10-8 ounce, avoirdupois

mile (mi) 1.609 kilometer

milligram (mg) 3.53 x 10-5 ounce, avoirdupois

ACRONYMS AND ABBREVIATIONS

ELISA Enzyme-Linked Immunosorbent Assay

GIS Geographic Information System

GPR Ground-Penetrating Radar

GPS global positioning system

GSSI Geophysical Survey Systems, Inc.

mg/kg milligram per kilogram

PAH Polycyclic Aromatic Hydrocarbon

PCB Polychlorinated Biphenyl

TPH Total Petroleum Hydrocarbon

μg/kg microgram per kilogram 

As Arsenic

Al Aluminum

Ba Barium

Be Beryllium

Bi Bismuth

Ca Calcium

Cd Cadmium

Co Cobalt

Cr Chromium

Cu Copper

Fe Iron

K Potassium

Li Lithium

Mg Magnesium

Mn Manganese

Mo Molybdenum

Na Sodium

Ni Nickel

P Phosphorus

Pb Lead

Sb Antimony

Sc Scandium

Sr Strontium

Ti Titanium

W Tungsten

Y Yttrium

Zn Zinc
Abstract 1

Sediment Quantity and Quality in 

Three Impoundments in Massachusetts

By Marc J. Zimmerman and Robert F. Breault

ABSTRACT

As part of a study with an overriding goal 

of providing information that would assist State 

and Federal agencies in developing screening 

protocols for managing sediments impounded 

behind dams that are potential candidates for 

removal, the U.S Geological Survey determined 

sediment quantity and quality at three locations: 

one on the French River and two on Yokum Brook, 

a tributary to the west branch of the Westfield 

River. Data collected with a global positioning 

system, a geographic information system, and 

sediment-thickness data aided in the creation of 

sediment maps and the calculation of sediment 

volumes at Perryville Pond on the French River in 

Webster, Massachusetts, and at the Silk Mill and 

Ballou Dams on Yokum Brook in Becket, 

Massachusetts. From these data the following 

sediment volumes were determined: Perryville 

Pond, 71,000 cubic yards, Silk Mill, 1,600 cubic 

yards, and Ballou, 800 cubic yards. Sediment 

characteristics were assessed in terms of grain size 

and concentrations of potentially hazardous 

organic compounds and metals.

 Assessment of the approaches and 

methods used at study sites indicated that groundpenetrating radar produced data that were 

extremely difficult and time-consuming to 

interpret for the three study sites. Because of these 

difficulties, a steel probe was ultimately used to 

determine sediment depth and extent for inclusion 

in the sediment maps. Use of these methods 

showed that, where sampling sites were 

accessible, a machine-driven coring device would 

be preferable to the physically exhausting, 

manual sediment-coring methods used in this 

investigation. Enzyme-linked immunosorbent 

assays were an effective tool for screening large 

numbers of samples for a range of organic 

contaminant compounds. An example calculation 

of the number of samples needed to characterize 

mean concentrations of contaminants indicated 

that the number of samples collected for most 

analytes was adequate; however, additional 

analyses for lead, copper, silver, arsenic, total 

petroleum hydrocarbons, and chlordane are 

needed to meet the criteria determined from the 

calculations.

Particle-size analysis did not reveal a clear 

spatial distribution pattern at Perryville Pond. 

On average, less than 65 percent of each sample 

was greater in size than very fine sand. The 

sample with the highest percentage of clay-sized 

particles (24.3 percent) was collected just 

upstream from the dam and generally had 

the highest concentrations of contaminants 

determined here. In contrast, more than 90 percent 

of the sediment samples in the Becket 

impoundments had grain sizes larger than very 

fine sand; as determined by direct observation, 

rocks, cobbles, and boulders constituted a 

substantial amount of the material impounded at 

Becket. In general, the highest percentages of the 

finest particles, clays, occurred in association with 

the highest concentrations of contaminants.

Enzyme-linked immunosorbent assays of 

the Perryville samples showed the widespread 

presence of petroleum hydrocarbons (16 out of 

26 samples), polycyclic aromatic hydrocarbons 
2 Sediment Quantity and Quality in Three Impoundments in Massachusetts

(23 out of 26 samples), and chlordane (18 out 

of 26 samples); polychlorinated biphenyls 

were detected in five samples from four 

locations. Neither petroleum hydrocarbons 

nor polychlorinated biphenyls were detected 

at Becket, and chlordane was detected in only 

one sample. All 14 Becket samples contained 

polycyclic aromatic hydrocarbons. Replicate 

quality-control analyses revealed consistent results 

between paired samples.

Samples from throughout Perryville Pond 

contained a number of metals at potentially toxic 

concentrations. These metals included arsenic, 

cadmium, copper, lead, nickel, and zinc. At 

Becket, no metals were found in elevated 

concentrations. 

In general, most of the concentrations 

of organic compounds and metals detected in 

Perryville Pond exceeded standards for benthic 

organisms, but only rarely exceeded standards for 

human contact. The most highly contaminated 

samples were collected from sites at the upstream 

and downstream ends of Perryville Pond.

To estimate the potential toxicity of the 

sediment samples to invertebrates on the basis 

of their concentrations of metals and organic 

contaminants, consensus-based sediment-toxicity 

guidelines were applied. The results of the 

calculations based on these guidelines highlighted 

the locations of potentially toxic contaminant "hot 

spots" in Perryville Pond. Interpretation of sample 

data from the Becket impoundments did not 

indicate the existence of similar pockets of 

potentially toxic contamination.

INTRODUCTION

Massachusetts has more than 3,000 dams, 

85 percent of which are over 50 years old. Many of 

these old dams are in hazardous states of abandonment 

and disrepair—conditions that are driving development 

of new approaches to management of the dams and 

the associated water resources. The primary options 

typically considered are dam removal or repair. A 

major issue with either of these options is the 

disposition of sediment that may have accumulated 

in the impoundments over decades or centuries. It may 

be necessary to redistribute or remove the impounded 

sediments to prevent or mitigate serious adverse 

effects downstream from the removal or repair of the 

dam. Redistribution of sediments through natural 

hydrodynamic processes after dam removal would 

minimize the associated costs. Existing physical and 

chemical data rarely suffice, however, for regulatory 

agencies to evaluate alternative options for sediment 

management, including natural redistribution and 

physical removal of sediments. Thus, a need exists for 

sampling protocols and screening methods to evaluate 

potential alternative options for management of 

impounded sediments.

The U.S. Geological Survey (USGS) evaluated 

sites visited by the River Restore Triage Team, 

under the auspices of the Riverways Program of the 

Massachusetts Department of Fisheries, Wildlife, and 

Environmental Law Enforcement, at Perryville Pond 

on the French River in the town of Webster, MA, and at 

the Silk Mill and Ballou impoundments on Yokum 

Brook, a tributary to the west branch of the Westfield 

River at Becket, MA (fig. 1). The hazardous condition 

of the Perryville Dam (fig. 2) has been a concern for a 

number of years. Its location, less than one-quarter 

mile from the Connecticut State line, and potential for 

failure and the subsequent uncontrolled release of 

potentially hazardous sediments, have made it an 

interstate issue. In Becket, the Silk Mill Dam (fig. 3) is 

filled with rocks, cobble, boulders, and sediment, and it 

is breached in several locations. The sediments at the 

bottom of the pond behind the Ballou Dam (fig. 4), 

which serves as a fire pond for the town, have displaced 

a large percentage of its water volume. Both of the 

dams in Becket impede the migration and spawning of 

Atlantic salmon (Salmo salar) from the Connecticut 

River.

Previous Studies and 

Historical Information

In 1987, the U.S. Environmental Protection 

Agency (USEPA) issued an Environmental Impact 

Statement (EIS) that listed several options for 

improving the French River's water quality (U.S. 

Environmental Protection Agency, 1987). The USEPA 

report included relevant data from previous studies and 

maps describing sediment distribution in Perryville 

Pond and other impoundments along the French River.
Introduction 3

According to the EIS, an earlier report had estimated 

the total volume of sediment in Perryville Pond as 

63,000 cubic yards.

A review of all relevant information for the 

watershed (called a due-diligence review) provided 

additional background information on possible sources 

of contamination. Review of documents describing 

results of environmental consultants' studies in the 

watershed upstream from Perryville Pond gave further 

credence to the information in the USEPA (1987) 

report that noted high concentrations of heavy metals 

and organic contaminants—legacies of the basin's 

industrial history. In Becket, the local historical 

commission indicated that the area upstream of both 

dams had supported mills at some time in the past. The 

commission also provided documents describing a 

flood in the 1920s that would have displaced any 

impounded sediments from behind the Silk Mill Dam. 

Further discussions with local officials revealed that 

sediments had been dredged from the Ballou 

impoundment approximately 15 years before this 

study. Thus, contaminants deposited before the 1920s 

at the Silk Mill Dam and before the mid-1980s at the 

Ballou Dam are no longer likely present.

Purpose and Scope

This report documents and evaluates sedimentscreening procedures used in this study for rapid 

and inexpensive surveys of sediment quantity and 

quality at three potential dam-removal projects in 

Massachusetts with the objective of providing 

regulatory agencies information needed to develop 

sediment-sampling protocols. The report details and 

presents interpretations of the results of grain-size, 

 200,000 400,000 600,000 800,000 1,000,000 FEET

200,000

FEET

400,000

600,000

Base from Massachusetts Executive Office of Environmental Affairs 

digital data, 1:24,000, 1991

Polyconic projection. 1927 North American datum

Massachusetts coordinate system mainland zone

PERRYVILLE

BALLOU

SILK MILL

WORCESTER

BOSTON

SPRINGFIELD

CONNECTICUT RIVER

Q

UINEBAUG RIVER

WESTFIELD RIVER

ATLANTIC OCEAN

Massachusetts

Bay

Nantucket

Sound

CONNECTICUT

RHODE ISLAND

MASSACHUSETTS

NEW HAMPSHIRE VERMONT

NEW YORK

50 MILES

0 50 KILOMETERS

0

Long Island Sound

25

25

42o

41o30'

42o

30'

 72o 73o 71o

Figure 1. Locations of the Perryville Dam on the French River in Webster, Massachusetts, and the Silk Mill and Ballou Dams on Yokum Brook in 

Becket, Massachusetts.
4 Sediment Quantity and Quality in Three Impoundments in Massachusetts

Figure 2. Perryville Dam, Webster, Massachusetts.

Figure 3. Silk Mill Dam, Becket, Massachusetts.
Methods of Assessment and Analysis 5

elemental, and organic-chemical analyses, and 

offers suggestions as to how future studies may 

benefit from improved approaches. The major 

groups of chemical analytes include metals, total 

polychlorinated biphenyls (PCBs), total polycyclic 

aromatic hydrocarbons (total PAHs), total petroleum 

hydrocarbons (TPHs), and total chlordane. This report 

also describes the areal extent of sediments deposited 

in the three impoundments and provides calculations 

of the sediment volumes. 

Acknowledgments

The authors express their thanks to several 

people whose support and encouragement were 

important factors in this project's success. We 

especially appreciate the enthusiasm of Karen Pelto, 

Massachusetts Department of Fisheries, Wildlife, and 

Environmental Law Enforcement, River Restore 

Program coordinator in the Massachusetts Executive 

Office of Environmental Affairs, in promoting this 

project and in obtaining its funding. Jacqueline Gillis, 

Harvard University, volunteered her professional 

expertise and many hours of her time to help us 

organize and prepare samples for analysis. This study 

also benefitted from the assistance of USGS colleagues 

Peter Joesten, Geophysicist, Storrs, CT; Britt Stock, 

Hydrologic Technician, Northborough, MA; Jason R. 

Sorenson and Marcus C. Waldron, Hydrologists, 

Northborough, MA; and James Degnan, Hydrologist, 

Pembroke, NH. Technical reviews by Leslie A. 

DeSimone, USGS, Northborough, MA; and Matt 

Liebmann, USEPA, Boston, MA, substantially 

improved the report's final version.

METHODS OF ASSESSMENT AND 

ANALYSIS

For this study, bathymetry and sediments were 

mapped at each of the three sites. Sediment samples 

were collected to provide data that accurately 

represented physical properties and chemical 

concentrations of sediments. Samples were analyzed at 

the Iowa and Massachusetts–Rhode Island District 

laboratories, and at the XRAL laboratories, Ontario, 

Figure 4. Ballou Dam, Becket, Massachusetts. Sediment-deposition island appears immediately upstream from the dam on the left 

side of the photograph.
6 Sediment Quantity and Quality in Three Impoundments in Massachusetts

Canada. The potential toxicity of all contaminants 

found in the samples was also analyzed. Qualitycontrol samples were collected and analyzed in the 

USGS Massachusetts–Rhode Island District laboratory 

and in the Columbia Analytical Services (CAS), Inc., 

laboratory, Kelso, Washington.

Bathymetric Mapping

Manually probing with a a steel rod determined 

water depths. Field reconnaissance of the study areas 

helped delineate land/water interfaces and water 

depths in the impoundments. Measurements totalled 

approximately 50 points in the Perryville and Silk Mill 

impoundments and about 40 points in the Ballou 

impoundment. The triangular irregular network (TIN) 

data model and topogrid function of the Environmental 

Systems Research Institute's ARC/INFO GIS software 

were used to generate bathymetric maps. Collecting 

additional field data would have made easier the 

computerized mapping process for both bathymetry 

and sediment extent.

Sediment Mapping

Initially, ground-penetrating radar (GPR) and 

a global positioning system (GPS) were used to 

determine sediment depth and extent. Later, probing 

with a steel rod replaced the use of GPR to determine 

sediment thickness to the point of refusal in the river 

bottom at Perryville and Becket. During the GPR 

component of the study, a GSSI (Geophysical Survey 

Systems, Inc.) SIR-10+ system with a 100-Megahertz 

transmitter and receiver and a Trimble GPS with 

submeter accuracy were used to provide data for 

interpretation.

GPR systems emit short pulses of 

electromagnetic energy from a transmitting antenna. 

The energy enters the material (in this study, the water 

column and bottom sediments in the impoundment) 

and passes through the material until it reaches an 

interface between materials (such as sediment/water 

and sediment/bedrock) with different dielectric 

constants. These interfaces reflect some of the energy 

that a surface receiver antenna subsequently detects; a 

computer then records the traveltime and strength of 

the signal. Interpretation of traveltimes from graphical 

GPR records, along with estimated radar-wave 

velocities for the different materials provides the basis 

for calculating bottom-sediment thicknesses. 

Aquatic vegetation does not hinder the use of 

GPR, which can work effectively in water as shallow as 

6 in. In this study, the GPR recording equipment was 

either carried in a boat while towing the antennae 

(fig. 5) or left on the shore while the antennae were 

dragged across land surfaces. 

Initial attempts were made to use GSSI RADAN 

software to interpret sediment thickness and waterdepth data from field recorders and from GIS software 

to develop sediment maps and determine sediment 

volumes. First, the GPS data were matched with 

existing topographic data from a geographic 

information system (GIS) to create maps depicting the 

trajectories traversed with the GPR unit. Multiple 

reflective surfaces, such as boulders, ledges, and clay 

layers that yielded ambiguous results, however, made it 

too difficult to confidently interpret sediment depths 

at specific locations in the GPR datasets. Finally, 

the Environmental Research Institute's TIN and 

ARC/INFO GIS software generated the sediment maps 

and calculated sediment volume on the basis of data 

from manual probing. 

Sediment-Sample Collection

One objective of this study was to provide data 

that accurately represented the existing physical 

properties and chemical concentrations of sediment in 

the sampled system in order to guide sedimentmanagement decisions with respect to dam removal. 

In collecting samples to meet this objective, different 

types of core samplers were used. Samples were 

processed either in the field immediately after 

collection, or shortly afterward in the Massachusetts–

Rhode Island District laboratory.

Data Representativeness and 

Number of Samples

Because this was a screening-level study, its 

scope (in terms of number of samples and analytes) 

was limited by design and budget. In order for 

informed management decisions to be made on the 

basis of these data, it is worthwhile to assess whether 

the goal of providing accurate representations of the 

system with a limited number of samples was achieved.
Methods of Assessment and Analysis 7

In other words, were enough data collected to 

determine a representative value (for example, the 

mean) for any given sedimentological parameter or 

constituent concentration and, if not, how many 

additional samples would be needed? 

Determining the appropriate number of samples 

needed to characterize the sediment quality at a 

potential dam-removal site calls for a two-stage 

approach. First, best scientific judgment (informed by 

the due-diligence survey) should guide the collection of 

sediment samples from spatially representative areas. 

Considerations include the locations of depositional 

environments and suspected or known contaminant 

sources, maximum sediment thickness, and location 

of fine particulates. In this study, the significant 

depositional zones emerged above the water surface. 

The initial number of samples should be chosen to 

capture the variability of the sediment chemistry both 

in terms of areal distribution and actual concentrations; 

if additional sampling is called for, the important 

locations and analytes will be known. Second, if the 

data are normally distributed, then the number of 

samples required to approximate a target statistic, for 

example, the true mean (eq. 1), can be calculated for 

a specific confidence level; that is, the number of 

sediment samples needed to describe "contamination" 

accurately depends on the degree of precision required. 

The number of samples needed to determine the 

mean value (or some other measure of central 

tendency) can be estimated from the sediment 

screening data and simple statistics: 

(1)

where

Ni is the number of data (or samples) for parameter 

or constituent i; tc is the value of student's t for desired 

two-sided confidence interval c with n-1 degrees of 

freedom, where n is the number of samples; sx,i is 

the variance for parameter or constituent i from 

the sediment-screening study; is the average 

concentration of parameter or constituent i from the 

sediment-screening study; and y is the acceptable error, 

in percentage of the mean (generally, 25-percent error 

is considered acceptable between laboratory 

Ni tc Sx i , × y xi ( ) ⁄ ×

2 = + 1

xi

Figure 5. Ground-penetrating radar being used to collect field data.
8 Sediment Quantity and Quality in Three Impoundments in Massachusetts

duplicates; therefore, estimation of the mean within the 

limits of laboratory error, with a 90-percent confidence 

level, is reasonable. The equation is based on three 

assumptions: (1) the variability of the sedimentscreening data approximates the "true" variability in 

physical properties and chemical concentrations of 

sediment behind the dam, (2) sediment sampling 

techniques and analysis were adequate (for example, 

sampling techniques did not contaminate samples), 

and (3) physical and chemical data are approximately 

normally distributed (Hakanson, 1984). If the data are 

not normally distributed, alternative equations may be 

used to calculate the statistic (Kratochvil and Taylor, 

1981).

In this study, a sufficient number of sampling 

sites was selected, on the basis of best scientific 

judgment, and in collaboration with State and Federal 

regulatory agencies, to provide a good representation of 

the distribution of contaminants in the impoundments. 

Limited time and budget also affected the number of 

samples that could be collected and analyzed. 

Collecting and Processing Samples

Three types of manual sediment corers were 

used to collect sediment samples: (1) an Ogeechee 

sand corer (Wildlife Supply Company, Buffalo, NY), 

(2) a custom-made plexiglass piston corer, and (3) a 

Livingstone corer (a multi-section piston corer). 

Obtaining and retaining a sediment core in the coring 

device can pose common, major problems: first, a plug 

can form at the opening of the corer and prevent 

additional material from entering; second, coarse 

material or very dense clays can prevent the corer from 

fully penetrating sediments; and third, a sediment core 

may slip out of the corer during retrieval. The piston 

corers, particularly the Livingstone corer, proved most 

effective in recovering cores (for example, fig. 6) 

under the variety of conditions at these sites, as they 

minimized all of the above problems and produced 

the longest, continuous cores. The multi-section 

Livingstone corer also has a serrated cutting edge that 

enabled it to penetrate dense clay layers. The sand corer 

regularly became blocked by clay or failed to retain its 

samples when attempts were made to retrieve them. 

Finally, all three types of corers required substantial 

physical effort to drive into and extract from the 

sediments, either from a boat or from a river bank.

In general, this investigation focused on areas 

likely to have fine-grained materials commonly 

associated with contaminants (Horowitz, 1991); 

furthermore, it was not feasible to sample coarse 

sediments with conventional equipment. Other sitespecific issues affected our ability to collect samples. 

In Perryville Pond, shallow water depths limited boat 

access to some areas, and purple loosestrife (Lythrum 

salicaria) infested by bumblebees covered others 

(fig. 7). At Becket, samples were collected from 

representative areas of these small impoundments; the 

coarse nature of the substrate, largely cobble and 

boulders, especially in the Silk Mill impoundment, 

made coring very difficult. Generally, the cores 

collected do not represent the complete sediment 

depth—a reflection of the difficulty of attempting to 

manually drive the corers.

Some of the samples were processed in the field 

immediately after collection, Afterwards, the corers 

were given thorough native-water rinses. In order to 

compare more recent deposits with older sediment 

deposits, cores were divided into subsections that 

yielded an 8-in-long sample representing the surface 

and at least one more sample taken from the deepest 

part of the core. Most cores were long enough to yield 

additional subsections representing middle regions of 

the core (fig. 8). (An alternative approach to collecting 

subsection samples might be to divide the core 

according to visual observations of changes in 

Figure 6. Examination of a sediment core collected with a Livingstone 

corer from Perryville Pond in Webster, Massachusetts.
Methods of Assessment and Analysis 9

sediment appearance.) After sectioning a core, samples 

were homogenized with a stainless-steel spoon in a 

precleaned, stainless-steel bowl. Following about 5 

minutes of homogenization, the samples were 

transferred to labelled, precleaned, quality-assured jars, 

and the jars were placed in sealed plastic bags and put 

into coolers containing ice. Cores that were not 

processed in the field were transported upright in 

coolers containing ice to the USGS Massachusetts–

Rhode Island District Office laboratory, where the 

same sectioning and homogenization procedures used 

in the field were followed. Processed samples were 

transferred to a 4°C refrigerator for storage prior to 

analysis or to shipping to an outside laboratory. For 

shipment to outside laboratories, sediment subsamples 

were put into labelled Whirl-Pak plastic bags that were, 

in turn, put into plastic bags that were then sealed, 

placed in coolers containing ice, and shipped for 

overnight delivery.

Laboratory Analyses

The USGS Iowa District Sediment Laboratory 

performed the particle-size analyses. A three-point 

pipet method (Guy, 1969) was used to obtain a particlesize distribution for particles ranging from larger than 

very fine sand (0.0625 mm) to particles as small as clay 

(0.002 mm and less). For budgetary reasons, a full set 

of samples was not sent to the Iowa laboratory for 

particle-size analysis; overall, about two thirds of the 

samples were analyzed for particle-size distribution. 

Using USEPA Methods EPA 3050B for sample 

digestion and EPA 200.8 for analysis of low-level trace 

metals, XRAL Laboratories of Ontario, Canada, 

analyzed sediment samples for 30 elements, including 

the likely contaminants arsenic, cadmium, chromium, 

copper, lead, nickel, and zinc. XRAL used inductively 

coupled, plasma-emission spectroscopy to determine 

elemental concentrations.

Figure 7. Centrally located island formed by sediment deposits and covered with purple loosestrife (Lythrum salicaria) in Perryville 

Pond in Webster, Massachusetts.
10 Sediment Quantity and Quality in Three Impoundments in Massachusetts

DEPTH BELOW SEDIMENT SURFACE, IN FEET

1

2

3

4

5

6

7

1

2

3

4

5

0

10

20

30

40

50

60

70

80

90

0

10

20

30

40

50

60

CORE SAMPLE LENGTHS, IN INCHES

A. PERRYVILLE CORE SECTIONS

B. SILK MILL AND BALLOU CORE SECTIONS

P1 P2 P3 P4 P5 P6 P7 P8 P9

S1

S1

S2 S3 S4 S5 B1

EXPLANATION

CORE IDENTIFIERS—P, Perryville, S, Silk Mill, and B, Ballou. 

Letters A, B, C, and D represent samples taken at various depths.

APPROXIMATE EXTENT OF SEDIMENT BELOW

RECOVERED CORE—NR, No Recovery

A AAA AAAA A

B B BB

B

B

B

C

A

B

C

C

C

D

C

B

C

B

C

NR

NR

NR

NR

NR

NR

NR

NR

NR

NR

NR

A

B

C

A

B

C

A

B

C

Figure 8. Sediment-core lengths, depths below sediment surface, and sample-section identifiers.
Methods of Assessment and Analysis 11

In the USGS Northborough laboratory, enzymelinked immunosorbent assays (ELISA) were used to 

analyze samples for total PAHs, TPHs (equivalent 

to a total BTEX1 analysis), total PCBs, and chlordane 

(including other cyclodiene pesticides). The 

Department of the Interior is a partner agency in the 

Federal Remediation Technologies Roundtable, which 

has identified the ELISA techniques applied here as 

appropriate for a screening study of this nature. 

(Federal Remediation Technologies Roundtable, 2002). 

Federal agencies, including the U.S. Navy, the 

U.S. Army, and the USEPA also regularly apply 

immunoassays in Rapid Sediment Characterization 

studies (Kirtay and Apitz, 2000; U.S. Army Corps of 

Engineers, 2000; Kirtay, 2001). USGS investigators 

have also used immunoassays, primarily in studies of 

pesticides in water (Aga and others, 1994; Schulze and 

others, 1990). In order to simplify discussion in this 

report, the familiar terms PAHs, TPHs, PCBs, and 

chlordane refer to our analytical methods and results. 

The ELISA analysis uses a competitive reaction of a 

mixture of analyte and an enzyme-labeled analog of the 

analyte for a limited number of antibody binding sites 

(Gruessner and others, 1995). Color-producing 

reagents are added to the mixture and allowed to 

incubate. After the excess reagent is removed, the color 

of the mixture is measured with a spectrophotometer; 

the analyte concentration is inversely proportional to 

color intensity. This study used RaPID Assay and 

EviroGard test-kit supplies and equipment purchased 

from Strategic Diagnostics, Inc., Newark, DE.

The analysis of each sample required 10.0 

± 0.1 g of sediment. Furthermore, the sample had to 

consist of at least 70 percent solid material after 

dewatering (Karen Peluso, Strategic Diagnostics, Inc., 

oral commun., 2001). To prepare the samples for 

analysis, substantially more than 10.0 g of sediment 

were dried overnight at room temperature in a fume 

hood. Prior experimentation indicated that this 

procedure would result in evaporation yielding sample 

material meeting the 70-percent criterion. 

After drying, 10.0 ± 0.1 g of sediment were 

weighed and placed in bottles for extraction by 

methanol. A premeasured volume of methanol was 

added to each sample bottle, the lid was replaced, and 

the sample was shaken for 1 minute. After allowing the 

sample material to settle for several minutes, a 

prescribed aliquot was removed for analysis according 

to the specific procedures defined by the manufacturer 

for the various analytes.

In general, these methods allow an analyst to 

report results quantitatively. Concentrations less than 

the method's detection level, however, are reported as 

non-detects; and concentrations that exceeded the 

maximum calibration values are reported in tables as 

"greater than," which is denoted with the ">" symbol. 

From the raw data, it is still possible to compare 

relative magnitudes among "greater than" values. In 

one set of analyses for chlordane, a good blank reading 

was not obtained, so only semiquantitative results were 

produced for this set. To maintain consistency, all the 

chlordane data have been reported semiquantitatively; 

that is, the detections are reported within a range of 

concentrations.

Potential for Adverse Biological Effects

In addition to the frequency with which 

contaminant concentrations exceeded specific, 

contaminant criteria, the potential toxicity of all the 

contaminants in sediment samples was estimated on 

the basis of consensus-based sediment-quality 

guidelines (U.S. Environmental Protection Agency, 

2000b.) This method of interpretation effectively 

assesses the management option of natural, hydrologic 

redistribution, or "no-action"; that is, the likely effect of 

leaving the sediments in place. These guidelines can be 

applied not just to individual contaminants, but also to 

a suite of metals and compounds to estimate their 

combined toxic effects. The environmental-sample 

concentration is divided by the probable effect 

concentration (PEC), the concentration above which, 

according to the consensus-based sediment-quality 

guidelines, adverse effects on benthic organisms are 

expected; the resulting value is called a PEC quotient. 

Then, in the application used here, the PEC quotients 

for each sample are averaged within their respective 

groups: metals, PAH, and PCB. The mean of the three 

group values is then determined. This average value, 

referred to as the Mean MPP (for Metal, PAH, and 

1BTEX refers to the benzene, toluene, ethylbenzene, and 

xylene low-molecular-weight components of petroleum hydrocarbon mixtures.
12 Sediment Quantity and Quality in Three Impoundments in Massachusetts

PCB), represents an equal weighting of the three 

contaminant groups. Additional groups of 

contaminants can be included, if adequate data are 

available. Finally, the Mean MPPs are compared to 

values associated with sediments of known toxicity to 

such standard test organisms as the amphipod Hyalella

azteca, or the insect larva Chironomus sp. Thus, this 

approach offers a means of estimating the toxicity of a 

given sediment sample without actually performing the 

toxicity tests.

Preparation of the data for the Mean MPP 

calculations followed procedures described by the 

USEPA (2000b). For environmental-sample 

concentrations lower than the reporting limit, the 

values were set to one half of the reporting limit. For 

values exceeding the maximum level of quantitation, 

the values were set to the maximum level of 

quantitation. For semiquantitative results reporting 

concentrations within a range of values, the sample 

concentrations were set to the midpoint of the range; 

for example, if the reported concentration was between 

100 and 600, then a value of 350 was used.

Quality Assurance and 

Quality Control

In addition to the quality-control (QC) samples 

analyzed in the Massachusetts–Rhode Island 

laboratory for organic constituents, 12 samples 

were sent to CAS for outside corroboration. CAS 

also performs its own internal QC analytical 

procedures. CAS's analytical methods differ from 

those used in the Massachusetts–Rhode Island 

laboratory (table 1); but to validate the approach using 

ELISA, methods were selected in consultation with 

CAS Project Chemist Ed Wallace (oral commun., 

2001), to yield comparable results. Because the 

ultimate disposition of contaminated sediments, as 

determined by regulatory agencies, would depend on 

the presence of specific compounds, interest focused 

on confirming that the ELISA method would yield 

neither false positive nor false negative results for the 

classes of compounds considered. However, James 

Eberts (Strategic Diagnostics, Inc., oral commun., 

2002) indicates that to meet regulatory applications, the 

ELISA methodology is designed to minimize the 

possibility of false negatives and may yield positively 

biased results; that is, with a screening approach 

intended to identify sites with elevated contaminant 

concentrations for additional evaluation and potentially 

for eventual remediation, it is preferable to 

overestimate concentrations slightly. 

ELISA analyses provide total concentrations for 

a group of compounds (table 1), because each specific 

antibody has a different affinity for each member of the 

group; the analyses are calibrated for a specific 

compound. Thus, ELISA results are reported as 

"totals." On the other hand, the chromatographic 

methods used by CAS yield data on each individual 

compound. For example, ELISA total PCB analyses 

yield a single value, whereas CAS provided the 

concentrations of seven individual PCB congeners 

(USEPA method 8081) that were summed to yield total 

concentrations. To compare them with our EnviroGard 

chlordane results, total chlordane concentrations were 

obtained by summing individual CAS organochlorinepesticide analyses. For comparison with our ELISA 

TPH and total PAH analyses, CAS provided oil-andgrease and PAH analyses (USEPA methods 1664M and 

8310), respectively. According to the USEPA (2000a), 

the oil-and-grease method may yield the same 

quantitative results as TPH analyses, but should not 

necessarily be expected to do so. The oil-and-grease 

method does not yield data on individual compounds.

The internal QC-duplicate analyses for samples 

analyzed by ELISA show some variability within 

analyte groups (table 2). The results are consistent and 

do indicate the general magnitude of the analyte 

concentrations. Despite the different methods of 

preparation and analysis between ELISA and CAS, a 

comparison of their results (table 3) further supports 

the usefulness of the ELISA methods as screening 

tools: only 2 of the 15 comparisons do not match in 

terms of detection compared to non-detection, and 

these disparities are both at the low ends of the 

concentration ranges for the methods that gave the 

detections (ELISA chlordane and CAS oil and grease). 

Although the samples were manually homogenized for 

5 minutes, it is possible that inhomogeneities remained 

that would have contributed to variability in the results, 

especially considering the small amount of material 

needed for an analysis. Matrix interference may also 

contribute to analytical variability.
Methods of Assessment and Analysis 13

ELISA CAS

PAH (EPA 4035) PAH (EPA 3550B)

Phenanthrene Phenanthrene

Fluoranthrene Fluoranthrene

Benzo(a)pyrene Benzo(a)pyrene

Pyrene Pyrene

Chrysene Chrysene

Anthracene Anthracene

Indeno(1,2,3-cd)pyrene Indeno(1,2,3-cd)pyrene

Benzo(b)fluoranethrene Benzo(b)fluoranethrene

Acenaphthylene Acenaphthylene

Benzo(k)fluoranthrene Benzo(k)fluoranthrene

Acenaphthalene Acenaphthene

Benzo(g,h,i)perylene Benz(a)anthracene

Naphthalene Naphthalene

Dibenzo(a,h)anthracene Dibenzo(a,h)anthracene

Fluorene

TPH Oil and Grease (EPA 1664M, 

Non-Polar Material) Total BTEX

m-Xylene

p-Xylene

Ethylenzene

Toluene

Benzene

Naphthalene

1,2,4-Trimethylbenzene

Anthracene

Styrene

Hexachlorobenzene

Phenanthrene

Creosote

1,3,5-Trimethylbenzene

Acenapthene

n-Propylbenzene

n-Hexane

n-Octane

n-Nonane

n-Heptane

Cyclohexane

n-Decane

Methylene Chloride

Trichloroethylene

PCB (EPA 4020) PCB (EPA 8082)

Aroclor 1254 Aroclor 1254

Aroclor 1260 Aroclor 1260

Aroclor 1248 Aroclor 1248

Aroclor 1242 Aroclor 1242

Aroclor 1262

Aroclor 1232 Aroclor 1232

Aroclor 1268

Aroclor 1016 Aroclor 1016

Aroclor 1221 Aroclor 1221

Chlordane (EPA 4041) Organochlorine Pesticides 

(EPA 8081A)

Chlordane Alpha-Chlordane

Gamma-Chlordane

Endosulfan I Endosulfan I

Endosulfan II Endosulfan II

Dieldrin Dieldrin

Alpha-BHC Alpha-BHC

Gamma-BHC Beta-BHC

Delta-BHC Delta-BHC

Heptachlor Heptachlor

Heptachor Epoxide

Aldrin Aldrin

Toxaphene Toxaphene

Endrin Endrin

Endrin Aldehyde

Endrin Ketone

Endosulfan Sulfate

Methoxychlor

4,4’-DDT

4,4’-DDE

4,4’-DDD

ELISA CAS

Table 1. Comparison of families of compounds that may be detected by the ELISA method used in this study in the U.S. Geological Survey 

Massachusetts–Rhode Island District laboratory and other methods used by Columbia Analytical Services, Inc., laboratory 

[CAS, Columbia Analytical Services, Inc.; ELISA, Enzyme-Linked Immunosorbent Assay; EPA 4035, EPA 4041, EPA 4020, EPA 3550 B, EPA 8082, EPA 

8081A, U.S. Environmental Protection Agency methods; PAH, polycyclic aromatic hydrocarbon; PCB, polychlorinated biphenyl; TPH, total petroleum 

hydrocarbon]
14 Sediment Quantity and Quality in Three Impoundments in Massachusetts

XRAL Laboratories analyzed four duplicate 

samples for metals; XRAL also performs its own 

internal QC blank- and standard-sample analyses. The 

results of the XRAL analyses, like the organic 

analyses, showed some variability (table 4, appendix). 

Replicate samples for analysis of particle-size 

distribution were not sent to the USGS Iowa Sediment 

Laboratory, but its internal QC procedures require the 

preparation of replicates for analysis (Guy, 1969), and 

the laboratory performed a single replicate analysis 

(sample P5C, table 5). A comparison of these two 

particle-size-distribution analyses showed good 

correspondence.

ANALYTICAL RESULTS FOR 

PERRYVILLE

The determinations of the bathymetry and the 

sediment distribution, and the sediment-volume 

calculations in the Perryville impoundment were based 

on interpretations of the data obtained by manually 

measuring water depths and probing the sediments 

(fig. 9). For simplicity's sake, brief, rather than full, 

USGS identifiers (table 5) will be used in discussions 

of specific samples and their locations. 

Bathymetric Mapping

Perryville Pond is a broad, shallow basin with a 

maximum water depth of about 6.7 ft at the times final 

depth measurements were made in June 2002. Depths 

ranged from about 2 to 4 ft in the main channel areas 

and were generally greatest along the western edge of 

the impoundment.

Sediment Volume and 

Thickness

Study results show the distribution of sediment 

in Perryville Pond similar to that depicted in the 

USEPA (1987) EIS. Approximately 71,000 cubic 

yards of sediment still remain trapped behind the 

Perryville Dam. The USEPA report estimated the total 

sediment volume as 63,000 cubic yards, but the full 

extent of the area included in that estimate is unclear.

Table 2. Comparison of quality-control replicate samples analyzed by 

the ELISA method for organic compounds

[Samples analyzed at the U.S. Geological Survey Massachusetts–Rhode 

Island District laboratory. PAH, polycyclic aromatic hydrocarbon; PCB, 

polychlorinated biphenyl; TPH, total petroleum hydrocarbon; mg/kg, 

milligrams per kilogram; μg/kg micrograms per kilogram; Q, indicates 

replicate quality-control sample; >, actual value is greater than value shown; 

--, not detected]

Sample

ID

PAH

(μg/kg)

TPH

(mg/kg)

PCB

(μg/kg)

Chlordane

(μg/kg)

P2A 1,120.00 -- -- 20–100

P2A-Q 1,470.00 -- -- --

P4C >5,000 14.80 540 >600

P4C-Q >5,000 17.20 600 >600

P8B >5,000 27.10 640 20–100

P8B-Q >5,000 16.10 760 20–100

Table 3. Comparison of ELISA results with duplicate quality-control 

sample results from Columbia Analytical Sevices, Inc.

[ELISA, results of analyses from the U.S. Geological Survey 

Massachusetts–Rhode Island District laboratory. CAS, Columbia Analytical 

Services, Inc.; PAH, polycyclic aromatic hydrocarbon; PCB, polychlorinated 

biphenyl; TPH, total petroleum hydrocarbon; mg/kg, milligrams per 

kilogram; μg/kg, micrograms per kilogram; >, actual value is greater than 

value shown; --, not detected]

Sample ID ELISA CAS

PAH (μg/kg)

P1B >5.00 174

P2A 1.12 3.72

S2B 2.61 2.41

S4A 4.34 .847

B1C >5.00 4.86

TPH (mg/kg)

P7B 4 4,000

P3C -- --

S4A -- 510

PCB (μg/kg)

P4C 540 560

P7C -- --

S4A -- --

Chlordane (μg/kg)

P4B 100–600 17.3

P5B -- --

S4A -- --

B1A 35 --
Analytical Results for Perryville 15

Table 4. Comparison of concentrations of selected metals in duplicate quality-control samples analyzed by XRAL Laboratories, Inc. 

[All concentrations in milligrams per kilogram; <, actual value is less than value shown]

Sample Arsenic Cadmium Copper Lead Nickel Zinc

P8A 35 5 346 459 26 897

32 4 316 420 25 823

P4C 8 2 239 179 21 263

6 1 226 163 21 247

P10 59 <1 44.9 72 15 75

59 <1 44.2 67 16 74.6

B1A <3 <1 11.5 20 14 87

 <3 <1 11.5 20 14 88.7

USGS location and

sample identifier

Brief sample and

map identifier

A3B-06-12.5 B1A

A3B-06-29.25 B1B

A3B-06-46 B1C

A3B-07-8 S1A

A3B-07-15.5 S1B

A3B-07-23 S1C

A3B-08-8 S2A

A3B-08-18.5 S2B

A3B-08-29 S2C

A3B-08-45 S3

A3B-09-8 S4A

A3B-09-25 S4B

A3B-09-42 S4C

A3B-09-58 S5

D2B-01-8 P4A

D2B-01-20 P4B

D2B-01-32 P4C

D2B-02-8 P5A

D2B-02-20 P5B

D2B-02-37 P5C

D2B-02-52 P5D

D2B-02-73 P5E

D2B-02-76 P5F

D2B-03-8 P6A

D2B-03-25 P6B

D2B-03-41 P6C

D2B-03-57 P6D

D2B-03-71 P6E

D2B-03-74 P6F

D2B-04-8 P7A

D2B-04-12 P7B

D2B-04-30 P7C

D2B-04-49 P7D

D2B-05-8 P8A

D2B-05-16 P8B

D2B-06-8 P9A

D2B-06-18 P9B

D2B-07-8 P2A

D2B-07-15 P2B

D2B-07-22 P2C

WLB-04-8 P3A

WLB-04-14 P3B

WLB-04-28.75 P3C

WLB-04-45 P3D

WLB-05-8 P1A

WB-05-19.5 P1B

D2Y-01 P10

USGS location and

sample identifier

Brief sample and

map identifier

Table 5. U.S. Geological Survey sample identifiers and shortened identifiers for maps used in this study

[Brief sample and map identifier: A brief format for use on maps and in discussions. The first letter identifies the impoundment (B, Ballou; P, Perryville; 

S, Silk Mill). The number indicates the location in the impoundment. The final letter (A–F), if one, indicates the depth from which the sample was collected 

(see fig. 8). USGS, U.S. Geological Survey]
16 Sediment Quantity and Quality in Three Impoundments in Massachusetts

6

5

4 3

5

4

5

2

4

3

1 1

1

1

1

2

2

3

3

4

7

5

6

5

3

4

2

4

4

3

4

6

5

6

6

3

3

4

8

8

9

8

8

8

5 5

5

7

7

Upstream extent of mapping

7

7

7

8

5

6

6

P9

P8

P1

P2

P3

P4

P5

P6

P7

P10

495,000 495,500 FEET

3

7

4,

5

0

0

3

7

4,

0

0

0

F

E

E

T

Base from U.S. Geological Survey 

digital data, 1:5,000, 2002 

Polyconic projection. 1927 North American datum

Massachusetts coordinate system mainland zone

0 250 500 FEET

0 50 100 METERS 

ROADS

SHORELINE

LINE OF EQUAL SEDIMENT

THICKNESS—Approximately

located. Interval 1 foot

LINE OF EQUAL WATER 

DEPTH—Approximately

located. Interval 1 foot

P9 CORE-SAMPLE LOCATION,

AND IDENTIFIER

EXPLANATION

Perryville Dam

6

2

EXTENT OF ISLAND

APPROXIMATE

French River

Figure 9. Bathymetric and bottom-sediment thickness map of Perryville Pond in Webster, Massachusetts.
Analytical Results for Perryville 17

Much of this sediment has formed a large island in the 

center of the impoundment (fig. 9). Changing water 

levels caused the above-water extent of the island to 

vary considerably between visits; on one visit (July 

2001), it was almost a peninsula, and on another visit 

(June 2002), it was mostly submerged. The sediments 

are deepest just upstream of the dam and extend in a 

fairly straight line away from it, with a maximum 

sediment thickness of 9.5 ft. Additional sediments may 

have accumulated in that area since the publication of 

the EIS. Moreover, changes in hydrology may have 

resulted in a net loss of sediment from some locations. 

The 1987 EIS indicates that the wetland plant, purple 

loosestrife, was uncommon in the Perryville Pond. 

During the July 2001 sampling trips, however, the 

exposed or shallow-water depositional zone extended 

well upstream from the front of the dam and was 

covered with this invasive species that reached heights 

of at least 8 ft; it towered over our heads. Water levels 

may have changed since the EIS was written; a decline 

in water level would have made the area more habitable 

by the loosestrife.

Sediment Cores

Cores were collected from nine locations within 

the impoundment (fig. 9) to provide the basis for 

assessing the physical and chemical characteristics of 

the sediments. A single sample was also collected from 

the right stream bank about 75 ft downstream from the 

dam (P10) for comparison with the chemistry of the 

impounded sediments. The longest cores (both 

approximately 6 ft long) came from sites P5 and P6 and 

were obtained with the Livingstone piston corer. At the 

bottoms of these cores, we found dense, coarse, fibrous 

material that may represent the remains of former bank 

or floodplain vegetation, indicating that coring had 

reached the bottom of the impoundment.

Particle-Size Analysis

Although the sediments were generally sandy, 

substantial fractions of some of the samples consisted 

of fine materials (table 6). Neither vertical nor 

horizontal patterns of particle-size distribution were 

apparent in the impoundment. Sample P5A 

(immediately upstream from the island) had the highest 

proportion (94.6 percent) of particles at least as large as 

fine sand (>0.0625 mm). Sample P8B contained the 

smallest proportion of particles larger than 0.0625 mm 

(23.7 percent) and the highest proportion (24.3 percent) 

of the smallest size fraction (clay; <0.002 mm); this 

sample was collected within a few yards of the dam. 

Two of the samples from site P3 also had relatively low 

percentages of the largest particles and high 

proportions of clays. 

Chemical Analyses

Sediment samples were analyzed for organic 

compounds and trace metals. Results of these analyses 

indicated frequent detections of high concentrations.

Organic Compounds

The highest concentrations of organic 

compounds were detected at the upstream end of the 

impoundment and close to the dam (table 7). No 

patterns in vertical distribution were apparent; but since 

cores could not be obtained from equivalent depths 

everywhere, such patterns may have gone detected. 

Raw data (those extrapolated data not reported 

quantitatively here because the concentrations 

exceeded calibration levels) obtained with the ELISA 

method indicated that the high concentrations of PAHs 

and PCBs at Perryville approximated the median 

values of samples collected in bottom sediments in the 

lower Charles River, Massachusetts; the lower Charles 

flows through a highly urbanized basin characterized as 

having contaminant levels generally exceeding those 

detected in national studies of urban rivers (Breault and 

others, 2000). The PAH concentrations were also 

comparable to those reported at Perryville in the 

USEPA (1987) report. The concentrations of total 

chlordane in some samples were only slightly less than 

the concentrations determined in the samples of the 

Charles River sediments.

PAHs were detected in all but three of the 

samples, and concentrations ranged from 204 μg/kg to 

greater than 5,000 μg/kg (the upper limit of 

quantitation). Although their values exceeded the limit 

of quantitation, the two highest values (from the raw 

data) came from samples P8B and P1A. Samples P2B, 

P2C, and P3B had no detectable concentrations of 

PAHs. 
18 Sediment Quantity and Quality in Three Impoundments in Massachusetts

Table 6. Sediment particle-size distribution for samples collected from Perryville Pond, Webster, and from Silk Mill and Ballou impoundments, Becket, 

Massachusetts, July 2000

[Numbers in parentheses are the particle size. Not all samples were analyzed for particle-size distribution. Data represent the percent of the sample in a size 

class. Sediment sizes are in millimeters. DUP, duplicate quality-control sample; >, greater than; <, less than]

Sample ID

Particle description

Fine sand

and larger

(>0.0625)

Smaller than

fine sand

(<0.0625)

Coarse silt

(0.0625–0.016)

Fine silt

(0.016–0.004)

Very fine silt

(0.04–0.002)

Clay

(<0.002)

Perryville Pond

P1A 79.36 20.6 9.5 4.2 1.5 5.4

P1B 82.55 17.4 8.1 3.2 1 5.1

P2A 51.28 48.7 31.3 6.8 1.8 8.8

P2B 52.5 47.5 33.9 4.2 2.9 6.5

P2C 44.04 56 37.4 7.7 1.8 9.1

P3A 72.06 27.9 13.8 4.3 1.8 8

P3B 38.01 62 45.4 3.5 2.2 10.9

P3C 24.61 75.4 50.1 10 2.8 12.5

P5A 94.56 5.4 3.5 .6 .2 1.1

P5B 80.94 19.1 13.8 1.8 .4 3.1

P5C 55.42 44.6 30 5.6 1.6 7.4

P5C-DUP 55.42 44.6 29.9 5.9 2.1 6.7

P6A 59.11 40.9 23 6.8 1.8 9.3

P6B 71.71 28.3 19.8 2.2 1.2 5.1

P6C 58.78 41.2 29.1 2.7 1.6 7.8

P7A 89.07 10.9 6.2 1.9 .3 2.5

P7B 74.97 25 11.7 4.1 1.9 7.3

P7C 86.01 14 9.9 1.5 .6 2

P8A 62.33 37.7 16.9 6.8 2.7 11.3

P8B 23.73 76.3 29.8 16.1 6.1 24.3

P10 86.78 13.2 8.4 1.2 .6 3

Silk Mill

S4A 92.15 7.8 4.8 1.3 0.5 1.2

S4B 89.84 10.2 5.8 1.5 .7 2.2

S4C 95.44 4.6 2.6 .8 .2 1

S5 96.87 3.1 1.5 .6 .2 .8

Ballou

B1A 82.24 17.8 11 2.7 0.8 3.3

B1B 98.8 1.1 .7 .1 .1 0.2
Analytical Results for Perryville 19

Sample

ID

PAH

(μg/kg)

TPH

(mg/kg)

PCB

(μg/kg)

Chlordane

(μg/kg)

Perryville Pond

P1A >5,000 21.1 660 >600

P1B >5,000 38.1 760 100–600

P2A 1,120 -- -- 20–100

P2B -- -- -- --

P2C -- -- -- --

P3A >5,000 17.2 640 100–600

P3B -- -- -- --

P3C 204 -- -- --

P4A >5,000 2.30 -- 100–600

P4B >5,000 9.60 -- 100–600

P4C >5,000 14.8 540 >600

P5A >5,000 1.10 -- 100–600

P5B 4,470 1.10 -- --

P5C 1,670 -- -- --

P5D 485 -- -- --

P6A >5,000 -- -- 100–600

P6B 4,160 1.00 -- 20–100

P6C >5,000 1.50 -- 20–100

P7A >5,000 1.10 -- 100–600

P7B >5,000 4.00 -- 20–100

P7C >5,000 -- -- --

P8A >5,000 10.0 -- 100–600

P8B >5,000 27.10 640 20–100

P9A >5,000 1.50 -- 20–100

P9B >5,000 1.20 -- 100–600

P10 >5,000 -- -- 20–100

Silk Mill

S1A 2,670 -- -- --

S1B 4,050 -- -- --

S1C >5,000 -- -- --

S2A 2,620 -- -- --

S2B 2,610 -- -- --

S2C 2,260 -- -- --

S3 3,070 -- -- --

S4A 4,340 -- -- --

S4B 2,200 -- -- --

S4C >5,000 -- -- --

S5 3,030 -- -- --

Ballou

B1A 2,660 -- -- 20–100

B1B 2,990 -- -- --

B1C >5,000 -- -- --

Sample

ID

PAH

(μg/kg)

TPH

(mg/kg)

PCB

(μg/kg)

Chlordane

(μg/kg)

Table 7. Results of ELISA analyses of organic sediment constituents in samples collected from Perryville Pond, Webster, and from Silk Mill and Ballou 

impoundments, Becket, Massachusetts

[PAH, polycyclic aromatic hydrocarbon; PCB, polychlorinated biphenyl; TPH, total petroleum hydrocarbon; μg/kg, micrograms per kilogram; mg/kg, 

milligrams per kilogram; >, actual value is greater than value shown; --, not detected]
20 Sediment Quantity and Quality in Three Impoundments in Massachusetts

TPHs were detected in 60 percent of the samples 

at concentrations ranging from 1 to greater than 30 

mg/kg. The highest concentrations were detected in 

samples P1A, P1B, P3A, P4C, and P8B. All samples 

from P1 and P8 had a detectable level of TPHs. The 

TPH concentrations exceeded by one to two orders of 

magnitude those reported for the individual BTEX 

compounds in the USEPA (1987) report (table 8).

Only five samples, collected at four sites, 

contained detectable concentrations of PCBs. These 

concentrations were detected in the same samples as 

the five highest TPH concentrations listed above. The 

PCB concentrations ranged from 540 to 760 μg/kg.

Chlordane was detected in 70 percent of the 

samples collected from Perryville Pond. Two samples 

(P1A, P4C) had concentrations exceeding 600 μg/kg.

Trace Metals

The following discussions of the results of 

analyses for trace elements focus on the concentrations 

of six metals: arsenic (As), cadmium (Cd), copper 

(Cu), lead (Pb), nickel (Ni), and zinc (Zn) (table 9) 

from among the 30 elements analyzed by XRAL 

Laboratories, Inc. (appendix, at back of report)2. 

Concentrations of metals differed widely, but the 

highest concentrations were generally detected in 

samples collected at sites nearest to the dam (sites P8 

and P9). Sample P8B had the highest concentrations of 

Cu and Pb, and among the highest concentrations of 

As, Cd, Ni, and Zn; this sample also had the highest 

proportion of clay material as indicated in the particlesize analysis. The highest concentration of As was 

found in the surface sample collected from the 

riverbank just downstream from the dam (site P10). 

High concentrations of As were also found in samples 

from sites in the impoundment closest to the dam; most 

of these concentrations were more than double that 

of the next highest As sample concentration. The 

three samples with the highest concentrations of Cd,

2This study included chromium as one of the target analytes. 

However, results suggested that sample processing may have introduced contamination and, thus, all references to chromium detections and concentrations have been deleted from this report. 

Cu, Pb, and Zn came from the same two sites in the 

impoundment nearest to the dam; again, like the highconcentration As samples, the concentrations of Cd, Cu, 

Pb, and Zn were commonly greater than twice the next 

highest sample concentration. Site P1, at the upstream 

end of the impoundment, also exhibited high 

concentrations of these metals. The concentration 

ranges for these metals appeared comparable to the 

results from the lower Charles River study (Breault and 

others, 2000). The metal-concentration ranges closely 

corresponded with values included in the USEPA 

(1987) report (table 8).

Table 8. Selected constituent concentrations in sediment samples from 

vegetated and open-water zones of Perryville Pond, Massachusetts, 1984

[U.S. Environmental Protection Agency, 1987. PAH, polycyclic aromatic 

hydrocarbon; TPH, total petroleum hydrocarbon; μg/kg, micrograms per 

kilogram; mg/kg, milligrams per kilogram; --, not detected]

Constituent Vegetated zone Open-water zone

Metals (mg/kg)

Arsenic 25 23

Cadmium 1.7 3.6

Chromium 220 630

Copper 83 350

Lead 81 220

Nickel 9 11

Zinc 180 440

PAH (μg/kg)

Acenaphthene 2,300 trace

Fluoranthene 4,700 15,000

Naphthalene 1,000 trace

Benzo(a)anthracene 2,300 12,000

Benzo(a)pyrene 1,200 9,000

Benzofluoranthene 1,400 10,000

Chrysene 2,000 10,000

Anthracene 3,400 11,000

Benzo(g,h,i)perylene 530 trace

Phenanthrene 8,000 22,000

Pyrene 8,100 23,000

TPH (μg/kg)

Acetone 160 --

Toluene 10 130

Chlorobenzene -- 49

Ethylene -- 12

Total xylene 10 15
Analytical Results for Perryville 21

Table 9. Concentrations of selected metals analyzed by XRAL Laboratories 

[All concentrations are milligrams per kilogram. DUP, duplicate control-quality sample; <, actual value is less than value shown]

Sample ID Arsenic Cadmium Copper Nickel Lead Zinc

P1A 12 2 336 22 250 385

P1B 6 1 116 18 219 288

P2A 4 <1 9.6 16 13 27.6

P2B 8 <1 6.1 19 11 25.8

P2C 8 <1 4.4 19 5 27.1

P3A 14 2 258 22 213 499

P3B 4 <1 5.3 16 5 21.5

P3C 10 <1 5.1 21 5 31.6

P4A 3 <1 25.6 13 64 74.3

P4B 6 <1 29.4 14 68 59.3

P4C 8 2 239 21 179 263

P5A 4 <1 27.7 16 67 51.5

P5B <3 <1 9 11 9 12.2

P5C 8 <1 3 11 5 13.7

P6A 7 2 247 24 211 177

P6B <3 <1 12.2 11 9 28.1

P6C <3 <1 16.1 14 15 29.8

P7A 5 <1 40.2 17 58 69

P7B 9 2 161 14 187 218

P7C <3 <1 10.5 10 20 20.7

P8A 35 5 346 26 459 897

P8B 54 5 734 22 528 842

P9A 28 10 533 20 515 824

P9B 10 2 194 16 136 134

P10 59 <1 44.9 15 72 75

S1A <3 <1 9.8 18 17 65.9

S1B <3 <1 12.4 14 15 61.6

S1C <3 <1 6.6 11 12 48.4

S2A <3 <1 11.7 15 26 78.3

S2B <3 <1 12.2 17 37 89.6

S2C <3 <1 16.4 15 43 106

S3 <3 <1 10.1 13 29 72

S4A <3 <1 9.3 13 11 56.7

S4B <3 <1 8.4 13 15 66

S4C <3 <1 7.7 10 15 51.8

S5 <3 <1 6.7 12 14 43

B1A <3 <1 11.5 14 20 87

B1B <3 <1 7.3 11 11 40.1

B1C <3 <1 10.1 12 12 46.6

DUP-P8A 32 4 316 25 420 823

DUP-P4C 6 1 226 21 163 247

DUP-P10 59 <1 44.2 16 67 74.6

DUP-B1A <3 <1 11.5 14 20 88.7
22 Sediment Quantity and Quality in Three Impoundments in Massachusetts

ANALYTICAL RESULTS FOR 

SILK MILL AND BALLOU

As with the Perryville Pond interpretations, 

this study bases its determination of the Becket 

impoundments' bathymetry, sediment distribution, and 

sediment volume on interpretation of the data obtained 

by manually probing the sediments and measuring the 

water and sediment depths. (figs. 10, 11). 

Bathymetric Mapping

The Silk Mill and Ballou Dams serve as passive, 

run-of-the-river dams that were built on rock outcrops 

where waterfalls likely existed. The impoundments 

behind these dams are relatively shallow (maximum 

depths of about 5 and 6 ft for Silk Mill and Ballou, 

respectively, at the times of our visits) and have 

little storage capacity due to sediment deposition.

Base from U.S. Geological Survey digital data, 1:5,000, 2002 

Polyconic projection. 1927 North American datum

Massachusetts coordinate system mainland zone

3

2

2

2

1

1

1

1

1

2

4

5

5

5

4

1

1

3

2

6

6

50 100 FEET

0 10 20 METERS

0

S1 S2/S3

S4/S5

171,500 171,600

4

8

8,

0

0

0

4

8

7,

9

0

0

4

8

7,

8

0

0

F

E

E

T

171,700 FEET

Silk Mill Dam

Extent of mapping

SHORELINE

LINE OF EQUAL SEDIMENT 

THICKNESS—Approximately

located. Interval 1 foot

LINE OF EQUAL WATER 

DEPTH—Approximately

located. Interval 1 foot

S2 CORE-SAMPLE LOCATION, 

AND IDENTIFIER

EXPLANATION

6

2

APPROXIMATE

EXTENT OF ISLAND

Yokum Brook

Figure 10. Bathymetric and bottom-sediment thickness map of Silk Mill impoundment, Becket, Massachusetts.
Analytical Results for Silk Mill and Ballou 23

Base from U.S. Geological Survey digital data, 1:5,000, 2002 

Polyconic projection. 1927 North American datum

Massachusetts coordinate system mainland zone

2

2

1 1 6

2

1

5

4

3

4

5

7

1

3

4

5

2

1

171,700 171,800 FEET

4

8

9,

3

0

0

4

8

9,

2

0

0

4

8

9,

1

0

0

F

E

E

T

50 100 FEET

0 10 20 METERS

0

Ballou Dam

SHORELINE

LINE OF EQUAL SEDIMENT

THICKNESS—Approximately

located. Interval 1 foot

LINE OF EQUAL WATER 

DEPTH—Approximately

located. Interval 1 foot

CORE-SAMPLE LOCATION

AND IDENTIFIER

6

2

B1

Yokum Brook

APPROXIMATE EXTENT 

OF ISLAND

B1 EXPLANATION

Figure 11. Bathymetric and bottom-sediment thickness map of Ballou impoundment, Becket, Massachusetts.
24 Sediment Quantity and Quality in Three Impoundments in Massachusetts

During the 1920s, the storage capacity of the Silk Mill 

impoundment was also reduced by a flood that 

deposited large boulders.

Most of Yokum Brook's flow in the Silk Mill 

impoundment passes along the west side. Under 

relatively high-flow conditions, the streamflow may 

split and surround the depositional island that has 

formed. Under low-flow conditions, the channel along 

the eastern bank may receive some ground-water 

discharge, but the channel basically becomes a 

backwater. At several points in the impoundment, there 

are gaps in the bottom sediment through which water 

and sediment can flow, eventually passing through an 

opening in the face of the dam. The most notable one is 

at the deepest point, between coring sites S1 and S2/3 

(fig. 10).

In and upstream from the Ballou Dam 

impoundment, Yokum Brook also splits to surround 

the main depositional island and other small outcrops. 

Walls along the east and west banks constrain the 

impoundment; and although the Ballou impoundment 

is smaller than that at the Silk Mill Dam, its pool area 

is relatively more extensive. 

Sediment Volume and Coring

Approximately 1,600 cubic yards of sediment 

remain trapped behind the Silk Mill Dam and about 

800 cubic yards are trapped behind the Ballou Dam. As 

in the case of Perryville Pond, most fine-grained 

sediment in these impoundments occurs as deposits 

forming large islands covered by a variety of plants, 

from shrubs and grasses to mature trees.

Cores were collected from three locations in the 

Silk Mill Pond (fig. 10) and from a single site in the 

Ballou pool (fig. 11). One of the Silk Mill locations 

was along the left bank, while the others were along 

the downstream end of the extensive depositional 

area that constituted an island and largely filled the 

impoundment. Pairs of cores, S2/S3 and S4/S5, were 

collected such that S3 and S5 represent sections 

immediately adjacent to and deeper than cores S2 and 

S4, respectively. Thus, in the Silk Mill impoundment, 

cores represent almost 5 ft of sediment deposition. The 

single core obtained in the Ballou impoundment was 

about 4 ft long (fig. 8).

Particle-Size Distribution

In contrast to the sediments at Perryville Pond, 

the sediments in samples collected from the Becket 

impoundments are uniformly characterized by a high 

percentage of particles at least as large as fine sand 

(0.0625 mm; table 6). Sample B1A contained the 

highest percentage (3.3 percent) of the smallest size 

class (clay).

Chemical Analyses

The ELISA analyses indicated no detectable 

concentrations of PCBs or TPHs (table 7) in either of 

the Becket impoundments. PAHs were detected in 

all samples at concentrations ranging from about 

2,000 mg/kg to greater than 5,000 mg/kg. The 

raw (extrapolated beyond the range of calibration 

concentrations) data indicated that the maximum PAH 

concentrations in the Becket impoundments fell well 

below those in Perryville. Chlordane was detected 

in a single sample (B1A) from the Ballou sediments. 

Its concentration was in the low range and was 

quantifiable as 34.9 μg/kg (listed as 20–100 μg/kg in 

table 7).

Potentially toxic metals were not detected in 

elevated concentrations (table 9). The concentrations 

were generally lower than the high concentrations 

detected in Perryville Pond. 

APPLICATION OF GUIDELINES FOR 

ASSESSING SEDIMENT CHEMISTRY

Data were analyzed to indicate whether or not 

enough samples were taken to adequately characterize 

sediment quality. This study also examined the relation 

of contaminant concentrations to particle-size fractions 

in order to provide useful information for deciding 

among options for sediment management (off-site 

disposal, on-site stabilization, or downstream 

redistribution). To categorize the potential toxicity to 

invertebrates of the sediment samples analyzed, mean 

MPP values derived from our data are compared with 

those assembled for the USEPA (2000b) consensus 

toxicity guidelines.
Application of Guidelines for Assessing Sediment Chemistry 25

Number of Samples Analyzed

Accurate characterization of sediment chemistry, 

in terms of mean concentrations calculated by using 

equation 1, for example, would call for substantially 

more samples from the Perryville impoundment 

than from the Becket impoundments (table 10). The 

due-diligence review revealed that the history of 

contamination in the Perryville drainage basin 

would suggest the likelihood of greater variability of 

contaminant concentrations associated with human 

activities (for example, copper, lead, mercury, nickel, 

and zinc) than in Yokum Brook, and hence, the need 

for additional samples to describe the mean. Many 

of the analytical concentrations falling at or below the 

levels of detection in the Becket impoundments showed 

little variability, and thus, would not require further 

sampling to adequately characterize the mean. In 

other words, the data collected from the Becket 

impoundments are representative, in terms of the 

mean, for most physical properties and chemical 

concentrations. It is important to note that this 

interpretation assumes that the "true" variability in 

physical properties and chemical concentrations was 

sampled in the impounded sediments.

On the other hand, regulations may prescribe 

a different method for determining a minimum 

sample number. For example, Massachusetts 

Department of Environmental Protection (MADEP) 

draft guidelines require projects at sites with greater 

than 10,000 cubic yards of sediment to collect a 

minimum of two samples; for sites with less than 

10,000 cubic yards, one sample per 1,000 cubic 

yards is required (S. Lipman, Massachusetts 

Department of Environmental Protection, written 

commun., 2001). These guidelines would have 

required only two samples each from Perryville Pond 

and Silk Mill Dam sediments and one from Ballou 

Dam. The data in table 10 suggest that these 

numbers would generally undersample Perryville 

and oversample Becket. This finding indicates

the value of a scientifically based approach to 

sediment-sampling design.

Table 10. Number of samples needed to define the mean concentrations 

of analytes within 25 percent and with 90 percent confidence for Perryville 

Pond and the two Becket impoundments (Silk Mill and Ballou combined), 

Massachusetts

[PAH, polycyclic aromatic hydrocarbon; PCB, polychlorinated biphenyl; 

TPH, total petroleum hydrocarbon]

Analyte Perryville Becket

Aluminum 9 4

Arsenic 70 1

Antimony 11 1

Barium 31 5

Beryllium 7 1

Bismuth 1 1

Cadmium 53 1

Calcium 9 3

Cobalt 10 3

Copper 91 5

Iron 7 2

Lanthanum 8 2

Lead 70 14

Lithium 6 3

Magnesium 6 2

Manganese 8 6

Molybdenum 7 5

Nickel 4 2

Phosphorus 21 2

Potassium 12 2

Scandium 11 2

Silver 88 2

Sodium 4 6

Strontium 13 4

Tin 47 1

Titanium 12 3

Tungsten 1 1

Vanadium 8 3

Yttrium 12 3

Zinc 87 6

Zirconium 11 4

Chlordane 61 1

PAH 14 6

PCB 2 1

TPH 116 1
26 Sediment Quantity and Quality in Three Impoundments in Massachusetts

Contaminant Concentrations and 

Exceedance Guidelines

Examination of the relation of contaminant 

concentrations to particle-size fractions showed that 

the highest concentrations of contaminants were 

found in association with the highest concentrations 

of clay particles. It is also worthwhile to compare 

the concentrations of contaminants with guidelines 

that are based on management criteria and potential 

biological effects. Breault and others (2000) presented 

concentration guidelines for potentially adverse effects 

of contaminated sediments on benthic organisms and 

on humans through epidermal contact (Ecosystem 

Conservation Directorate Evaluation and Interpretation 

Branch, 1995). To compare this study's results with 

those guidelines, the work of Breault and others (2000) 

has been summarized and synthesized with the 

USEPA consensus sediment-toxicity guidelines (U.S. 

Environmental Protection Agency, 2000b). The 

guidelines list Threshold Effect Levels (TEL), the 

concentrations below which adverse effects on benthic 

organisms are rarely observed, and Probable Effect 

Levels (PEL), the concentrations above which adverse 

effects on benthic organisms are commonly observed, 

for some specific polycyclic aromatic hydrocarbons in 

freshwater sediments (table 11). The PEL contrasts 

with the PEC, the concentration above which one 

expects to observe adverse effects on benthic 

organisms.

At neither Perryville nor Becket did any of 

the PAH (within the quantifiable range) or TPH 

concentrations exceed the criteria for Probable Effect 

Concentration (PEC) (22,800 μg/kg) or for human 

contact (800,000 μg/kg); but additional testing,

if necessary, can confirm the true magnitudes of 

the concentrations. None of the detected PCB 

concentrations exceeded the human-contact threshold, 

but the values did exceed both the TEL and PEL 

for freshwater benthic organisms. These PCB 

concentrations are comparable to those detected in the 

lower Charles River Basin (Breault and others, 2000), 

but are considerably less than those found in the East 

Branch of the Housatonic River Basin in Massachusetts 

Table 11. Sediment-quality guidelines for freshwater benthic organisms 

and human-contact data

[Breault and others, 2000. PAH, polycyclic aromatic hydrocarbon; PCB, 

polychlorinated biphenyl; TPH, total petroleum hydrocarbon; PEL, 

Probable Effect Level, concentration above which adverse effects are 

commonly observed; PEC, Probable Effect Concentration, concentration 

above which adverse effects are expected (USEPA, 2000b); TEL, Threshold 

Effect Level, concentration below which adverse effects are rarely observed. 

μg/kg, micrograms per kilogram; mg/kg, milligrams per kilogram; --, no 

value available]

Constituent or class TEL PEL PEC Human 

contact

Organics (μg/kg)

TPH -- -- -- 800,000

Total PAH -- -- 22,800 --

Total PCB 34.1 277 676 2,000

Total chlordane 4.5 8.9 17.6 1,000

Metals (mg/kg)

Arsenic 5.9 17 33.0 30

Cadmium 0.6 3.53 4.98 30

Chromium 37.3 90 111 1,000

Copper 35.7 197 149 --

Nickel 18 35.9 48.6 300

Lead 35 91.3 128 300

Zinc 123 315 459 2,500
Application of Guidelines for Assessing Sediment Chemistry 27

(Harris, 1997) where a major point-source discharge 

caused the contamination. Because the Minimum 

Detection Level (MDL) by ELISA for total chlordane, 

20 μg/kg, is greater than either the TEL or PEL, all 

detections exceeded those levels; that is, many 

samples from Perryville and one from Ballou had 

concentrations exceeding these levels. Only two 

chlordane concentrations were greater than 600 μg/kg; 

therefore, these concentrations could exceed the 

human-contact criterion.

Many of the sediment samples collected from 

Perryville Pond contained metal concentrations that 

exceeded criteria for benthic organisms and human 

contact. In general, the samples with the highest metal 

concentrations came from sites P1, P8, and P9; 

additional samples with high metals concentrations 

came from sites P3, P4, P6, and P7. Arsenic 

concentrations, where detected, generally exceeded the 

TEL but not the PEL; only at P8, P9, and P10 did the 

concentrations exceed the PEL and the human-contact 

criterion of 30 mg/kg. The MDL for Cd (1 mg/kg) is 

greater than the TEL (0.6 mg/kg), so it is conceivable 

that all samples had concentrations of at least that 

value; only samples from sites P8 and P9 exceeded the 

PEL; none exceeded the human-contact criterion of 

30 mg/kg. About half (12) of the Cu concentrations 

exceeded the TEL, but only seven exceeded the PEL; 

currently, there is no human-contact criterion. Sixty 

percent of the samples had Pb concentrations 

exceeding the TEL, and most of those also exceeded 

the PEL; three samples collected at sites P8 and P9 

exceeded the human-contact criterion. For Ni, 11 

samples exceeded the TEL but none exceeded the PEL. 

For Zn, 10 samples exceeded the TEL and 5 the PEL.

At Becket, there were no samples in which 

metal concentrations exceeded human-contact 

guidelines. Only two samples contained Pb 

concentrations slightly in excess of the TEL. No 

samples for the other metals considered here exceeded 

the toxicity standards we use.

Contaminants and Their 

Potential Toxicity

Examination of sample results for potential 

toxicity showed that samples collected at Perryville 

sites 1, 3, 4, 8, and 9 stood out in terms of potential 

toxicity; samples P8B and P9A had the highest MPP 

values, 1.7 and 0.90, respectively. Individual samples 

from sites 1, 3, and 4 in Perryville Pond also exceeded 

the 0.5 value. This analysis reinforces the biological 

implications of the high chemical-contaminant 

concentration levels. Samples from the two Becket 

impoundments exhibited mean MPP values in the 

lowest potential toxicity category found in this study 

(0.1<Mean MPP<0.5). 

In terms of toxicity, only the P8B sediments 

seem likely to prove lethal to 50 percent or more of the 

test organisms (table 12) on the basis of the analysis of 

this particular dataset. Other combinations of analytes, 

including chromium, would be expected to yield 

different results. The HA28 (Hyalella azteca 28-day 

toxicity test) seemed more sensitive at high values of 

mean MPP than the shorter duration tests. However, 

for mean MPP values less than 0.5, toxicity, as 

indicated by the HA28 test, was relatively low. These 

interpretations of toxicity, based on a comparison with 

all the data compiled by the USEPA (2000b), do not 

take into account regional variability in the results of 

the computations. None of the data in the compilation 

were derived from studies in New England, let alone in 

the specific basins in Massachusetts.
28 Sediment Quantity and Quality in Three Impoundments in Massachusetts

Table 12. Incidence of toxicity based on Probable Effect Concentration (PEC) quotients in samples from Perryville Pond, 

Webster, and from Silk Mill and Ballou impoundments, Becket, Massachusetts

[Percent species toxicity data from U.S. Environmental Protection Agency, 2000b. Mean MPP, average of PEC quotients; 

X, indicates the range within which the Mean MPP value lies; CS10, Chironomus spp. 10-day toxicity test; HA10, Hyalella 

azteca 10-day toxicity test; HA28, Hyalella azteca 28-day toxicity test; NC, not calculated; <, less than; >, greater than]

Percent toxicity by mean MPP range

Mean MPP range

<0.1 0.1<0.5 0.5<1.0 1.0<5.0 >1.0

Sample

ID

Mean

MPP

HA10:

HA28:

CA10:

19

4

29

26

6

35

38

50

35

49

NC

50

66

100

60

P1A 0.75 X

P1B .66 X

P2A .18 X

P2B .18 X

P2C .17 X

P3A .71 X

P3B .16 X

P3C .18 X

P4A .27 X

P4B .28 X

P4C .60 X

P5A .27 X

P5B .22 X

P5C .18 X

P6A .46 X

P6B .22 X

P6C .24 X

P7A .28 X

P7B .42 X

P7C .23 X

P8A .78 X

P8B 1.17 X X

P9A .90 X

P9B .40 X

P10 .38 X

S1A .21 X

S1B .23 X

S1C .23 X

S2A .21 X

S2B .22 X

S2C .22 X

S3 .22 X

S4A .22 X

S4B .20 X

S4C .23 X

S5 .20 X

B1A .21 X

B1B .20 X

B1C .23 X
Summary and Conclusions 29

SUMMARY AND CONCLUSIONS

The U.S. Geological Survey, in cooperation with 

River Restore, a program within the Massachusetts 

Executive Office of Environmental Affairs (EOEA), 

initiated a study to help provide State and Federal 

agencies with information needed to develop sedimentscreening procedures and protocols to enable rapid and 

inexpensive surveys of sediment quantity and quality at 

potential dam-removal sites. The Perryville and Becket 

impoundments were selected to represent "end 

members" of the broad range of sediment-chemistry 

conditions that might be encountered in Massachusetts 

impoundments. Prior information indicated that the 

sediments in Perryville Pond would contain high 

concentrations of contaminants, while the sediments at 

the Becket sites would show minimal numbers of 

detections and low concentrations. In a general sense, 

these expectations were met. Polycyclic aromatic 

hydrocarbons, total petroleum hydrocarbons, and 

chlordane in high concentrations were commonly 

found in samples from Perryville, whereas total 

petroleum hydrocarbons and polychlorinated biphenyls 

were not detected at all in Becket samples. The 

widespread occurrence of polycyclic aromatic 

hydrocarbons in samples from both locations is a 

particularly interesting finding; if these compounds are 

so commonplace in sediments in a setting as rural and 

undeveloped as Becket, then they are likely to be 

present in sediments at levels at least as high 

throughout Massachusetts and elsewhere. 

The use of enzyme-linked immunosorbent assays 

to screen sediment samples for classes of organic 

compounds proved a highly useful and cost-effective 

approach; with these screening results in hand, it is 

relatively easy matter to focus more detailed analysis 

on areas of known contamination. The U.S. Army 

Corps of Engineers, the U.S. Navy, and the USEPA 

apply and recommend similar approaches.

In this study, GPR proved to be of limited 

usefulness for measuring sediment thickness in 

impoundments containing boulders, ledges, and 

heterogeneous bottom materials. Although detailed 

information was obtained, it was difficult and timeconsuming to interpret the raw data; in the end, a 

simpler method, manual probing with a rod, proved 

more effective. Nevertheless, reaching such a 

conclusion represents another important finding of this 

study.

Collecting numerous sediment cores led to an 

improved understanding of the variability of 

contaminant concentrations, particularly in the 

Perryville impoundment. The number of sediment 

cores collected and samples analyzed were adequate 

for minimal regulatory screening requirements; 

however, minimal does not imply that, for example, 

only two samples would be required in a system known 

to be highly contaminated. Because of the potential for 

horizontal and vertical variability, analysis of too few 

surface grab samples alone could lead to misleading 

interpretations. Determining the mean concentrations 

of particular analytes within a specified confidence 

interval requires a more rigorous approach to 

identifying the number of samples to collect. In an 

heuristic example, the number of samples analyzed 

was sufficient to adequately characterize the mean 

concentrations of most of the analytes in all the 

impoundments. However, at Perryville, some of the 

contaminants with highly variable concentrations, such 

as Cu, Zn, Pb, As, TPH, and chlordane, would have 

required additional samples to characterize the mean 

on the basis of our assumptions and parameters.

Using manual coring techniques to collect 

samples proved exhausting and frustrating at times. 

The option of using a lightweight, motorized, piston 

corer could improve the entire sampling process; 

however, accessibility and cost may preclude its use 

in particular locations.

From this experience, it seems that a phased 

approach is essential for sediment-characterization 

studies. After completing the due-diligence phase, 

a thorough reconnaissance of the site, including a 

preliminary examination of sediment and basin 

physical parameters prior to sample collection, should 

be conducted. A preliminary screening round of 

sampling and analysis can guide more thorough, 

focused sampling, if deemed necessary. Determining 

the physical characteristics of the sediment can guide 

sampling efforts toward areas where are likely 

contaminants associated with clays and other fine 

particles. 

The application of the consensus-based 

guidelines by using the Probable Effect Concentration 

values is a new approach that gives an assessment of 

potential sediment toxicity to invertebrate test 

organisms at sites where multiple contaminants are 

present. In this study, the results suggest the existence 

of a few pockets of toxic sediments at Perryville Pond; 
30 Sediment Quantity and Quality in Three Impoundments in Massachusetts

data from the Becket sediments do not indicate the 

existence of similar "hot spots." However, geographic 

differences may also prove important in interpreting 

data; the consensus-based guidelines used few data 

from studies in the northeastern United States. 

Currently, this approach to assessing sediment toxicity 

remains under development; there are other 

permutations of analyzing these data that could be 

applied. For example, individual contaminants or 

compounds, instead of compound classes, could be 

weighted, or additional potentially toxic analytes could 

be included. Moreover, different compounds or classes 

of compounds likely contribute unequally to overall 

sediment toxicity. The methods described for 

predicting sediment toxicity offer promise and further 

development of the methods deserves encouragement 

and thorough testing.

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Determination of alachlor and its sulfonic acid 

metabolite in water by solid-phase extraction and 

enzyme-linked immunosorbent assay: Analytical 

Chemistry, v. 66, p. 1495–1499.

Breault, R.F., Reisig, K.R., Barlow, L.K., and Weiskel, P.K., 

2000, Distribution and potential for adverse biological 

effects of inorganic elements and organic compounds in 

bottom sediment, lower Charles River, Massachusetts, 

U.S. Geological Survey Water-Resources Investigations 

Report 00-4180, 70 p.

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Interpretation Branch, 1995, Interim sediment quality 

guidelines: Ottawa, Ontario, Canada, Soil and Sediment 

Quality Section, Guidelines Division, 12 p.

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field sampling and analysis guide: Federal Remediation 

Technologies Roundtable, accessed November 6, 2002, 

at URL, http://www.frtr.gov/site/analysismatrix.html

Gruessner, B., Shambaugh, N.C., and Watzin, M.C., 1995, 

Comparison of an enzyme immunoassay and gas 

chromatography/mass spectrometry for the detection of 

atrazine in surface waters: Environmental Science and 

Technology, v. 29, p. 251–254.

Guy, H.P., 1969, Laboratory theory and methods for 

sediment analysis: U.S. Geological Survey Techniques 

of Water-Resources Investigations, book 5, chap. C1, 

58 p.

Hakanson, L., 1984, Sediment sampling in different aquatic 

environments—Statistical aspects: Water Resources 

Research, v. 20, p. 41–46.

Harris, S.L., 1997, Inorganic and organic constituents and 

grain-size distribution in streambed sediment and 

ancillary data for the Connecticut, Housatonic, and 

Thames River Basins study unit, 1992–94: U.S. 

Geological Survey Open-File Report 96-397, 39 p.

Horowitz, A.J., 1991, A primer on sediment-trace element 

chemistry (2d ed.): Boca Raton, FL, Lewis Publishers, 

136 p.

Kirtay, V.J., and Apitz, S.E., 2000, Rapid sediment 

characterization (RSC) tools for ecological risk 

assessments: Argonne National Laboratory, 

Environmental Assessment Division, Issue Paper, 

accessed on November 6, 2002, at URL 

http://web.ead.anl.gov/ecorisk/issue/pdf/rsc.pdf, 22 p.

Kratochvil, B., and Taylor, J.K., 1981, Sampling for 

chemical analysis: Analytical Chemistry, v. 53, 

p. 924A–938A.

Schulze, P.A., Capel, P.D., Squillace, P.J., and Helsel, D.R., 

1990, A laboratory and field evaluation of a portable 

immunoassay test for triazine herbicides in 

environmental water samples: U.S. Geological Survey 

Office of Water Quality Technical Memorandum 90.08, 

22 p.

U.S. Army Corps of Engineers, 2000, Site assessment report 

and risk characterization of PCBs at Birch Hill 

Reservoir, Royalston, Massachusetts: Task Order 28, 

Contract DACW33-96-D-0004, variously paged.

U.S. Environmental Protection Agency, 1987, Final 

environmental impact statement for the French River 

cleanup program in Massachusetts and Connecticut: 

Boston, MA, U.S. Environmental Protection Agency, 

variously paged.

_____2000a, Analytical method guidance for EPA method 

1664A implementation and use (40 CFR part 136): 

EPA/821-R-00-003, 44 p.

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consensus-based freshwater sediment guidelines: EPA 

905/R-00-007, 33 p.
Appendix: Complete Listing of Elemental Analyses

Performed by XRAL Laboratories, Inc.

Appendix 33

Appendix. Results of elemental analyses performed by XRAL Laboratories, Inc., Ontario, Canada—Continued

Sample Antimony

(mg/kg)

Arsenic

(mg/kg)

Barium

(mg/kg)

Beryllium

(mg/kg)

Bismuth

(mg/kg)

Cadmium

(mg/kg)

Calcium

(%)

Cobalt

(mg/kg)

Copper

(mg/kg)

Iron

(%)

P1A 6 12 165 0.5 <5 2 0.21 5 336 1.65

P1B <5 6 83 <.5 <5 1 .15 5 116 1.13

P2A <5 4 23 .8 <5 <1 .17 8 9.6 1.46

P2B <5 8 18 .8 <5 <1 .11 7 6.1 1.49

P2C <5 8 31 .8 <5 <1 .13 6 4.4 1.83

P3A <5 14 91 .6 <5 2 .25 7 258 1.59

P3B <5 4 16 .7 <5 <1 .1 5 5.3 1.35

P3C <5 10 40 .9 <5 <1 .16 10 5.1 2.01

P4A <5 3 112 <.5 <5 <1 .15 4 25.6 1

P4B <5 6 46 <.5 <5 <1 .12 2 29.4 .83

P4B-Q <5 6 113 <.5 <5 1 .19 4 226 1.34

P4C <5 8 122 <.5 <5 2 .21 4 239 1.46

P5A <5 4 36 <.5 <5 <1 .13 4 27.7 .9

P5B <5 <3 18 <.5 <5 <1 .09 3 9 .71

P5C <5 8 18 .6 <5 <1 .13 2 3 1

P6A <5 7 122 .8 <5 2 .21 5 247 1.54

P6B <5 <3 30 <.5 <5 <1 .15 2 12.2 .87

P6C <5 <3 29 <.5 <5 <1 .14 3 16.1 .87

P7A <5 5 48 <.5 <5 <1 .18 4 40.2 1.16

P7B <5 9 55 <.5 <5 2 .16 4 161 .96

P7C <5 <3 28 <.5 <5 <1 .12 2 10.5 .72

P8A 11 35 219 1.5 <5 5 .34 9 346 1.67

P8A-Q 10 32 197 1.8 <5 4 .33 9 316 1.58

P8B 15 54 164 .9 <5 5 .34 7 734 1.83

P9A 14 28 108 .8 <5 10 .36 6 533 1.93

P9B <5 10 58 .6 <5 2 .2 6 194 1.21

P10 <5 59 51 .5 <5 <1 .3 4 44.9 2.84

P10-Q <5 59 52 .5 <5 <1 .3 4 44.2 2.81

S1A <5 <3 70 <.5 <5 <1 .37 8 9.8 1.79

S1B <5 <3 58 <.5 <5 <1 .44 7 12.4 2.03

S1C <5 <3 50 <.5 <5 <1 .29 6 6.6 1.79

S2A <5 <3 74 <.5 <5 <1 .41 9 11.7 2.4

S2B <5 <3 78 <.5 <5 <1 .35 7 12.2 2.28

S2C <5 <3 99 .5 <5 <1 .46 7 16.4 2.11

S3 <5 <3 65 <.5 <5 <1 .34 6 10.1 1.73

S4A <5 <3 57 <.5 <5 <1 .43 6 9.3 1.8

S4B <5 <3 58 <.5 <5 <1 .33 6 8.4 1.75

S4C <5 <3 49 <.5 <5 <1 .31 7 7.7 1.79

S5 <5 <3 39 <.5 <5 <1 .25 4 6.7 1.51

B1A <5 <3 81 <.5 <5 <1 .41 8 11.5 2.1

Appendix. Results of elemental analyses performed by XRAL Laboratories, Inc., Ontario, Canada

[Q, indicates quality-control duplicate sample; mg/kg, milligrams per kilogram; %, percent; <, actual value is less than value shown]
34 Sediment Quantity and Quality in Three Impoundments in Massachusetts

B1A-Q <5 <3 83 <0.5 <5 <1 0.42 9 11.5 2.12

B1B <5 <3 39 <.5 <5 <1 .24 5 7.3 1.32

B1C <5 <3 51 <.5 <5 <1 .38 6 10.1 1.72

Appendix. Results of elemental analyses performed by XRAL Laboratories, Inc., Ontario, Canada—Continued

Sample Lanthanum

(mg/kg)

Lead

(mg/kg)

Lithium

(mg/kg)

Magnesium

(%)

Manganese

(mg/kg)

Nickel

(mg/kg)

Molybdenum

(mg/kg)

Phosphorus

(%)

Potassium

(%)

Scandium

(mg/kg)

P1A 13.4 250 15 0.26 159 22 3 0.13 0.14 1.1

P1B 12.1 219 13 .22 108 18 3 .09 .11 .9

P2A 24.3 13 23 .3 347 16 2 .05 .08 1.3

P2B 25.4 11 25 .38 238 19 2 .05 .06 1.7

P2C 31.8 5 26 .45 203 19 1 .03 .09 2.6

P3A 17.1 213 18 .35 256 22 2 .14 .18 1.3

P3B 25.7 5 25 .33 173 16 1 .04 .07 1.6

P3C 33.3 5 32 .53 228 21 2 .04 .11 3

P4A 12.2 64 13 .23 110 13 2 .05 .16 1.2

P4B 10.2 68 12 .2 82 14 2 .05 .11 1

P4B-Q 26.2 163 13 .22 118 21 2 .1 .14 1

P4C 27.7 179 14 .24 128 21 2 .11 .15 1

P5A 12.2 67 13 .2 122 16 2 .06 .12 1

P5B 11.2 9 12 .17 94 11 2 .07 .05 .6

P5C 21.6 5 17 .25 149 11 1 .03 .07 1.3

P6A 32.3 211 19 .35 249 24 3 .18 .13 1.1

P6B 14.5 9 14 .21 105 11 1 .08 .07 .7

P6C 16 15 18 .28 111 14 1 .06 .06 .9

P7A 14 58 11 .2 201 17 3 .08 .12 .8

P7B 15.9 187 13 .22 139 14 2 .1 .11 .9

P7C 12.3 20 12 .2 96 10 <1 .07 .08 .7

P8A 29.1 459 21 .35 196 26 3 .24 .17 1.8

P8A-Q 26.2 420 20 .33 184 25 3 .22 .16 1.9

P8B 24.9 528 26 .46 157 22 2 .28 .25 1.4

P9A 22.1 515 24 .46 207 20 2 .16 .31 2.1

P9B 16 136 19 .31 126 16 2 .11 .14 1.1

P10 14.7 72 16 .29 240 15 2 .13 .16 1.1

P10-Q 15.8 67 16 .29 238 16 2 .13 .16 1.2

S1A 9.7 17 10 .31 206 18 3 .08 .18 1.7

S1B 10 15 10 .32 227 14 2 .08 .21 2.3

S1C 9 12 9 .27 198 11 2 .08 .2 1.8

S2A 12.7 26 13 .37 430 15 3 .1 .24 2.4

S2B 12.8 37 15 .39 338 17 3 .1 .23 1.8

S2C 14.3 43 16 .44 196 15 3 .09 .27 2.2

S3 10.6 29 12 0.34 228 13 2 0.08 0.2 1.7

Appendix. Results of elemental analyses performed by XRAL Laboratories, Inc., Ontario, Canada—Continued

Sample Antimony

(mg/kg)

Arsenic

(mg/kg)

Barium

(mg/kg)

Beryllium

(mg/kg)

Bismuth

(mg/kg)

Cadmium

(mg/kg)

Calcium

(%)

Cobalt

(mg/kg)

Copper

(mg/kg)

Iron

(%)
Appendix 35

S4A 9.5 11 9 .32 355 13 2 .08 .2 2

S4B 1.6 15 11 .3 211 13 2 .09 .19 1.6

S4C 1.5 15 10 .29 227 10 2 .07 .19 2.1

S5 8.6 14 9 .25 190 12 2 .06 .17 1.6

B1A 12.6 20 13 .4 328 14 3 .09 .24 2

B1A-Q 12.3 20 13 .41 332 14 3 .1 .25 2.1

B1B 8.4 11 8 .26 145 11 1 .06 .18 1.6

B1C 10.5 12 9 .33 224 12 2 .07 .23 2.4

Appendix. Complete listing of elemental analyses performed by XRAL Laboratories, Inc., Ontario, Canada—Continued

Sample ID Silver

(mg/kg)

Sodium

(%)

Strontium

(mg/kg)

Tin

(mg/kg)

Titanium

(%)

Tungsten

(mg/kg)

Vanadium

(mg/kg)

Yttrium

(mg/kg)

Zinc

(mg/kg)

Zirconium

(mg/kg)

P1A 5.2 0.04 17.5 <10 0.04 <10 24 6.8 385 6.4

P1B .4 .03 16.7 16 .03 <10 15 5.6 288 2.6

P2A <.2 .04 11.6 <10 .08 <10 18 12.7 27.6 2.5

P2B .3 .03 7.3 <10 .09 <10 21 15.1 25.8 2.2

P2C <.2 .04 9.7 <10 .1 <10 26 16.9 27.1 3.5

P3A 1 .04 19.4 <10 .05 <10 23 7.8 499 3

P3B .3 .03 7.2 <10 .08 <10 18 12.3 21.5 2.3

P3C <.2 .04 10.9 <10 .11 <10 30 17.6 31.6 3.2

P4A <.2 .04 16.7 <10 .03 <10 12 4.7 74.3 4.5

P4B .3 .03 12.6 <10 .02 <10 11 3.8 59.3 3.9

P4B-Q 2.9 .04 15.8 <10 .03 <10 20 5 247 5.8

P4C 2.9 .04 16.9 <10 .03 <10 21 5.3 263 5.4

P5A .3 .03 10.7 <10 .03 <10 11 4.3 51.5 3

P5B <.2 .03 7.5 <10 .03 <10 8 4.2 12.2 .9

P5C .3 .03 8.5 <10 .06 <10 14 8.8 13.7 2.6

P6A 1.6 .04 17.8 <10 .05 <10 33 8.2 177 4.3

P6B <.2 .04 10.3 <10 .04 <10 11 5.5 28.1 1.4

P6C <.2 .03 8 <10 .05 <10 13 6.2 29.8 1

P7A .4 .05 13.9 <10 .03 <10 13 5.6 69 2.3

P7B 1 .03 12.8 <10 .03 <10 13 5.2 218 2.6

P7C <.2 .03 8.1 <10 .03 <10 9 4.5 20.7 1

P8A 3.4 .05 36.8 15 .04 <10 26 10 897 4.6

P8A-Q 3.6 .04 34.5 12 .04 <10 26 9.4 823 4.8

P8B 2.7 .05 29.9 30 .05 <10 27 11.6 842 3.6

P9A 1.1 .06 27.3 63 .05 <10 26 11.2 824 5.7

P9B .2 .04 13 68 .05 <10 16 7.5 134 1.8

P10 .5 .06 20 <10 .04 <10 19 7.8 75 3.2

P10-Q .5 .07 20.2 <10 .04 <10 19 7.7 74.6 3.6

S1A <.2 .03 10.8 <10 .07 <10 17 8.4 65.9 1.6

S1B <0.2 0.07 12.2 <10 0.08 <10 20 9.1 61.6 2.4

Appendix. Results of elemental analyses performed by XRAL Laboratories, Inc., Ontario, Canada—Continued

Sample Lanthanum

(mg/kg)

Lead

(mg/kg)

Lithium

(mg/kg)

Magnesium

(%)

Manganese

(mg/kg)

Nickel

(mg/kg)

Molybdenum

(mg/kg)

Phosphorus

(%)

Potassium

(%)

Scandium

(mg/kg)
36 Sediment Quantity and Quality in Three Impoundments in Massachusetts

S1C .3 .03 7.7 <10 .07 <10 15 7.6 48.4 2.4

S2A <.2 .05 10.8 <10 .1 <10 23 11.6 78.3 2

S2B <.2 .03 10.8 <10 .1 <10 23 10.5 89.6 1.5

S2C .2 .04 15.4 <10 .1 <10 24 11.5 106 2.3

S3 <.2 .03 9.9 <10 .08 <10 18 8.6 72 1.4

S4A <.2 .05 10.5 <10 .08 <10 17 8.8 56.7 2.2

S4B <.2 .03 9 <10 .07 <10 16 8.5 66 1.5

S4C <.2 .04 8.8 <10 .07 <10 16 8.2 51.8 2.4

S5 <.2 .03 7.3 <10 .06 <10 13 6.3 43 2.2

B1A <.2 .04 10.6 <10 .1 <10 21 10.2 87 2.7

B1A-Q <.2 .04 11 <10 .1 <10 21 10.4 88.7 2.4

B1B <.2 .03 6.3 <10 .06 <10 12 5.9 40.1 2.7

B1C .3 .06 9.9 <10 .08 <10 17 8.6 46.6 3.1

Appendix. Complete listing of elemental analyses performed by XRAL Laboratories, Inc., Ontario, Canada—Continued

Sample ID Silver

(mg/kg)

Sodium

(%)

Strontium

(mg/kg)

Tin

(mg/kg)

Titanium

(%)

Tungsten

(mg/kg)

Vanadium

(mg/kg)

Yttrium

(mg/kg)

Zinc

(mg/kg)

Zirconium

(mg/kg)