Sediment Studies in the Assabet River,

Central Massachusetts, 2003

By Marc J. Zimmerman and Jason R. Sorenson

Part 1

Sediment Distribution and Chemistry in Six Impoundments in the 

Assabet River, Central Massachusetts

Part 2

Phosphorus Dynamics in a Wastewater-Dominated Impoundment, 

Hudson, Massachusetts

In cooperation with the

Massachusetts Department of Environmental Protection and the

U.S. Environmental Protection Agency

Scientific Investigations Report 2005-5131

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

Gale A. Norton, Secretary

U.S. Geological Survey

Charles G. Groat, Director

U.S. Geological Survey, Reston, Virginia: 2005

For sale by U.S. Geological Survey, Information Services

Box 25286, Denver Federal Center

Denver, CO 80225

For more information about the USGS and its products:

Telephone: 1-888-ASK-USGS

World Wide Web: http://www.usgs.gov/

Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply 

endorsement by the U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report.

Suggested citation:

Zimmerman, M.J., and Sorenson, J.R., 2005, Sediment studies in the Assabet River, central Massachusetts, 2003: 

U.S. Geological Survey Scientific Investigations Report 2005-5131, 87 p.
Contents

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

The Assabet River and its Sediments ........................................................................................................2

Part 1. Sediment Distribution and Chemistry in Six Impoundments in the Assabet 

River, Central Massachusetts ........................................................................................................5

Study Design...................................................................................................................................................5

Mapping of Bathymetry and Sediment Thickness ..........................................................................5

Selection of Sediment-Sampling Sites..............................................................................................5

Collection of Sediment Cores .............................................................................................................5

Sample Preparation .............................................................................................................................7

Analytical Methods...............................................................................................................................7

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

Sediment Thickness and Bathymetric Maps ..........................................................................................13

Sediment Chemistry of the Assabet River Impoundments ...................................................................21

Elemental Analyses ............................................................................................................................21

Phosphorus.................................................................................................................................21

Toxic Trace Elements.................................................................................................................27

Reactive Sulfide .........................................................................................................................28

Organic Analyses................................................................................................................................28

Volatile Organic Compounds and Organochlorine Pesticides ...........................................29

Polycyclic Aromatic Hydrocarbons........................................................................................29

Polychlorinated Biphenyls .......................................................................................................29

Extractable Petroleum Hydrocarbons....................................................................................34

Potential for Adverse Biological Effects.........................................................................................34

Sediment Distribution and Chemistry—Possible Implications for Sediment 

Management...................................................................................................................................39

Part 2. Phosphorus Dynamics in a Wastewater-Dominated Impoundment, 

Hudson, Massachusetts ...............................................................................................................41

Introduction...................................................................................................................................................41

Site Selection and Sample Collection ......................................................................................................42

Reconnaissance and Site Selection................................................................................................42

Field Measurements and Collection of Phosphorus and Chloride Samples.............................42

Quality Control.....................................................................................................................................42

Field Study of Phosphorus Dynamics.......................................................................................................44

Site-Specific Profiles .........................................................................................................................45

Changes in Phosphorus Storage......................................................................................................45

Mass Balance (Chloride:Total Phosphorus)...................................................................................49

Phosphorus Dynamics in the Hudson Impoundment.............................................................................49

Summary........................................................................................................................................................50

Acknowledgments.......................................................................................................................................50

References....................................................................................................................................................51

iii
Figures

1. Map showing the Assabet River Basin in central Massachusetts ......................................3

2–8. Photographs showing:

2. A probe being used to collect data for a map of sediment thickness and extent ....6

3. A piston corer being prepared for collection of a sediment core...............................6

4. A Teflon piston being used to extrude core into a polycarbonate tube .....................7

5. An extruded core.................................................................................................................8

6. A sample being collected for volatile organic compound analysis ............................8

7. A sample being collected for polychlorinated biphenyl and pesticide analyses .....9

8. A sample being prepared for metal analysis ..................................................................9

9–14. Maps showing:

9. Sediment thickness, phosphorus bulk-sediment profiles, exceedances of 

TEL (threshold effect level) and PEL (probable effect level) guidelines for 

toxic trace elements, and potential for sediment toxicity to aquatic life 

from cores collected in Aluminum City impoundment in Northborough, 2003 .......14

10. Sediment thickness, phosphorus bulk-sediment profiles, exceedances of 

TEL (threshold effect level) and PEL (probable effect level) guidelines for 

toxic trace elements, and potential for sediment toxicity to aquatic life 

from cores collected in Allen Street impoundment in Northborough, 2003............15

11. Sediment thickness, phosphorus bulk-sediment profiles, exceedances of 

TEL (threshold effect level) and PEL (probable effect level) guidelines for 

toxic trace elements, and potential for sediment toxicity to aquatic life 

from cores collected in Route 85 impoundment in Hudson, 2003.............................16

12. Sediment thickness, phosphorus bulk-sediment profiles, exceedances of 

TEL (threshold effect level) and PEL (probable effect level) guidelines for 

toxic trace elements, and potential for sediment toxicity to aquatic life 

from cores collected in Gleasondale impoundment in Stow, 2003...........................17

13. Sediment thickness, phosphorus bulk-sediment profiles, exceedances of 

TEL (threshold effect level) and PEL (probable effect level) guidelines for 

toxic trace elements, and potential for sediment toxicity to aquatic life 

from cores collected in Ben Smith impoundment in Maynard, 2003........................19

14. Sediment thickness, phosphorus bulk-sediment profiles, exceedances of 

TEL (threshold effect level) and PEL (probable effect level) guidelines for 

toxic trace elements, and potential for sediment toxicity to aquatic life 

from cores collected in Powdermill impoundment in Maynard and Acton, 

2003......................................................................................................................................20

15, 16. Graphs showing:

15. Total polycyclic aromatic hydrocarbon concentrations in core samples 

from six impoundments in the Assabet River, 2003 .....................................................30

16. Concentrations of selected polychlorinated biphenyl Aroclors detected in 

core samples from six impoundments in the Assabet River, 2003............................30

17. Map showing Hudson impoundment with sampling sites for phosphorusrelease dynamics study, July to September 2003 .................................................................43

18. Photograph showing platform attached to pushpoint sampler in preparation 

for pore-water sampling............................................................................................................44

iv
19. Chart showing A, Total and orthophosphorus and dissolved oxygen watercolumn profiles at five stations in the Hudson impoundment, July to 

September 2003. Depth is given as vertical distance from sediment surface to 

water surface. B, Rainfall and changes in estimated total phosphorus storage 

in the Hudson impoundment, July to September 2003 .........................................................46

Tables

1. Identifiers and depths for samples collected in six impoundments in the 

Assabet River, Massachusetts.................................................................................................10

2. Sediment-quality guidelines for freshwater organisms, human contact, and 

Massachusetts landfill reuse ...................................................................................................22

3. Concentrations of phosphorus, in percent, in bulk sediment samples from six 

impoundments in the Assabet River Basin, 2003...................................................................23

4. Mean and median concentrations of trace metals in New England stream 

sediments.....................................................................................................................................25

5. Summary statistics of total bulk phosphorus concentrations in sediment 

samples from six impoundments in the Assabet River Basin, 2003 ...................................26

6. Median and mean values for total polycyclic aromatic hydrocarbon 

concentrations detected in sediment samples from six impoundments in the 

Assabet River Basin, 2003 .........................................................................................................29

7. Concentrations of polychlorinated biphenyl Aroclors in sediment samples 

from six impoundments in the Assabet River Basin, 2003 ...................................................31

8. Concentrations of extractable petroleum hydrocarbons in sediment samples 

from six impoundments in the the Assabet River Basin, 2003.............................................35

9. Incidence of toxicity, in percent, and mean MPP values calculated from 

Probable Effect Concentration quotients for sediment samples from the six 

impoundments in the Assabet River Basin, 2003...................................................................38

10. Selected characteristics of six impoundments in the Assabet River Basin.....................40

11. Mean and median total phosphorus and orthophosphorus concentrations, in 

milligrams per liter, of all samples in the water column or pore water at each 

sampling station in the Hudson impoundment, July to September 2003...........................44

12. Estimated phosphorus storage in the Hudson, Massachusetts, impoundment 

sections, July to September 2003 ............................................................................................48

13. Ratios of chloride to total phosphorus at the inflow and outflow of the Hudson 

impoundment, July to September 2003 ...................................................................................49

14. Concentrations of selected metals in sediment samples from six impoundments 

in the Assabet River Basin, 2003 ..............................................................................................55

15. Results of all elemental analyses performed by SGS Canada, Inc., Mineral 

Services, Toronto, Ontario, Canada, of sediment samples from six 

impoundments in the Assabet River Basin, 2003...................................................................60

16. Concentrations of polycyclic aromatic hydrocarbons detected in sediment 

sampless from six impoundments in the Assabet River Basin, 2003 .................................76

17. Water-quality data collected during study of phosphorus dynamics in the 

Hudson impoundment, 2003 ......................................................................................................82

v
Conversion Factors, Datums, Water-Quality Information and 

Abbreviations

Multiply By To obtain

centimeter (cm) 0.3937 inch (in.)

cubic meter (m3) 35.31 cubic foot (ft3)

cubic meter (m3) 1.308 cubic yard (yd3) 

inch (in.) 2.54 centimeter (cm)

inch (in.) 25.4 millimeter (mm)

kilogram (kg) 2.2046 pound, avoirdupois (lb)

kilometer (km) 0.6214 mile (mi)

liter (L) 61.02 cubic inch (in3) 

meter (m) 3.281 foot (ft) 

meter (m) 1.094 yard (yd) 

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

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

milliliter (mL) 0.06102 cubic inch (in3)

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:

°F=(1.8×°C)+32

Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83).

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius 

(μS/cm at 25°C).

Concentrations of chemical constituents in water are given either in milligrams per liter (mg/L) 

or micrograms per liter (μg/L).

As arsenic

Cd cadmium

Cr chromium

Cu copper

DO dissolved oxygen

EPH extractable petroleum hydrocarbon

GC gas chromatography

GIS geographic information system

MS mass spectrometry

Ni nickel

PAH polycyclic aromatic hydrocarbon

Pb lead

PCB polychlorinated biphenyl 

PEC probable effect concentration 

PEL probable effect level

PVC polyvinyl chloride

RL reporting level

TEL threshold effect level

TIN triangular irregular network

TMDL total maximum daily load

TPH total petroleum hydrocarbon

USEPA U.S. Environmental Protection Agency

VOC volatile organic compound

Zn zinc

vi
Sediment Studies in the Assabet River, 

Central Massachusetts, 2003

By Marc J. Zimmerman and Jason R. Sorenson

Abstract

From its headwaters in Westborough, Massachusetts, to 

its confluence with the Sudbury River, the 53-kilometer-long 

Assabet River passes through a series of small towns and 

mixed land-use areas. Along the way, wastewater-treatment 

plants release nutrient-rich effluents that contribute to the 

eutrophic state of this waterway. This condition is most obvious where the river is impounded by a series of dams that have 

sequestered large amounts of sediment and support rooted and 

floating macrophytes and epiphytic algae. The water in parts 

of these impoundments may also have low concentrations of 

dissolved oxygen, another symptom of eutrophication.

All of the impoundments had relatively shallow maximum water depths, which ranged from approximately 2.4 to 

3.4 meters, and all had extensive shallow areas. Sediment volumes estimated for the six impoundments ranged from approximately 380 cubic meters in the Aluminum City impoundment 

to 580,000 cubic meters in the Ben Smith impoundment. The 

other impoundments had sediment volumes of 120,000 cubic 

meters (Powdermill), 67,000 cubic meters (Gleasondale), 

55,000 cubic meters (Hudson), and 42,000 cubic meters (Allen 

Street).

The principal objective of this study was the determination of sediment volume, extent, and chemistry, in particular, 

the characterization of toxic inorganic and organic chemicals 

in the sediments. To determine the bulk-sediment chemicalconstituent concentrations, more than one hundred sediment 

cores were collected in pairs from the six impoundments. 

One core from each pair was sampled for inorganic constituents and the other for organic constituents. Most of the cores 

analyzed for inorganics were sectioned to provide information 

on the vertical distribution of analytes; a subset of the cores 

analyzed for organics was also sectioned. Approximately 200 

samples were analyzed for inorganic constituents and 100 for 

organics; more than 10 percent were quality-control replicate 

or blank samples. 

Maximum bulk-sediment phosphorus concentrations in 

surface samples from the impoundments increased along a 

downstream gradient, with the exception of samples from the 

last impoundment, where the concentrations decreased. In 

addition, the highest phosphorus concentrations were generally in the surface samples; this finding may prove helpful if 

surface dredging is selected as a means to control phosphorus 

release from sediments. There is no known relation, however, 

between bulk-sediment concentration of phosphorus and the 

concentrations of phosphorus available to biota. 

Potentially toxic metals, including arsenic, cadmium, 

chromium, copper, nickel, lead, and zinc were frequently 

measured at concentrations that exceeded U.S. Environmental 

Protection Agency sediment-quality guidelines for the 

protection of aquatic life and that occasionally exceeded 

Massachusetts Department of Environmental Protection guidelines governing landfill disposal (reuse). Due to the effects of 

matrix interference and sample dilution on laboratory analyses, neither pesticides nor volatile organic compounds were 

detected at any sites. However, samples collected in other 

studies from nearby streams indicated the possibility that pesticides might have been detected in the impoundments if not 

for these analytical problems. Although polychlorinated biphenyl concentrations, as individual Aroclors, generally exceeded 

published U.S. Environmental Protection Agency guideline 

concentrations for potential effects on aquatic life, the U.S. 

Environmental Protection Agency guideline concentrations 

for human contact or the Massachusetts guidelines for landfill 

reuse were rarely exceeded. Concentrations of polycyclic 

aromatic hydrocarbons, both individually and total, frequently 

were greater than guideline concentrations. Concentrations 

of total extractable petroleum hydrocarbons did not exceed 

Massachusetts guideline concentrations in any samples.
When the sediment analytes from surface samples are 

considered together to compare their potential toxicity to 

aquatic organisms, it is clear that sediment exposure is likely 

to have harmful effects. By most measures, samples from the 

first and last impoundments in the sequence had the poorest 

sediment quality with respect to the degree and the frequency 

with which guideline concentrations were exceeded.

A consortium of towns along the river has investigated 

a range of options aimed at controlling concentrations of 

nutrients, phosphorus in particular, released from wastewatertreatment plants into the river and its impoundments. The 

second part of this study examined the changes in phosphorus 

concentrations in surface and pore waters in one impoundment 

during a 2-month period. The results were used to determine whether the sediments could release sufficient amounts 

of phosphorus to render ineffective decreased phosphorus 

releases from treatment plants. Knowledge of sediment 

characteristics and chemistry will allow local water managers 

to choose among the sediment-management options that may 

be considered for the Assabet River: decreasing concentrations of phosphorus released from treatment plants, partial or 

complete dredging, dam removal or modification, phosphorus 

sequestration by chemical treatment, and making no changes.

To investigate the dynamics of phosphorus concentrations in the impoundment in Hudson, Massachusetts, water 

samples were collected weekly at five locations. In addition 

to ortho- and total phosphorus, some samples were analyzed 

for chloride, which served as a conservative tracer for waters 

released from upstream wastewater-treatment plants. At each 

location, data were collected to provide water-column profiles 

of temperature, dissolved oxygen, and specific conductance.

In the study of phosphorus dynamics in the impoundment 

in Hudson, Massachusetts, phosphorus concentrations varied 

over time, primarily in bed-sediment samples, at the offchannel sampling locations where the water column was stratified. These variations, including some substantial increases in 

phosphorus concentrations in pore-water samples, however, 

did not appear to lead to increases in phosphorus exported 

from the impoundment. This observation suggests that most 

of the phosphorus released from the sediments was recycled 

internally in the impoundment.

Although net phosphorus storage did vary, it did not 

generally increase with time as total phosphorus entered the 

water column from sediments in stagnant areas in the Hudson 

impoundment. Physical and redox processes seem to control 

phosphorus release from sediments to the water column. 

These findings and the results of other studies indicate that 

the amount of phosphorus released from sediments over a 

yearly cycle was relatively small compared to the amount of 

phosphorus entering the system from upstream wastewatertreatment plants. 

The Assabet River and its Sediments 

The 53-km-long Assabet River is impounded by a 

series of dams as it flows northeastward from its source at 

the A1 impoundment in Westborough through the towns of 

Northborough, Marlborough, Hudson, Stow, Maynard, and 

Acton (fig. 1). Along the way, municipal wastewater-treatment 

plants in Westborough, Marlborough, Hudson, and Maynard 

discharge nutrient-rich effluent to the river. 

Historically, the Assabet River Basin was characterized 

by small towns with centers along or near the river. Much of 

the surrounding land was forested or farmed. Dams impounding reaches of the Assabet River served to power the mills 

that consti­tuted the economic bases for the towns along the 

river. Modern industries have also substantially contributed 

to the area’s economic development. Water- and sedimentquality characteristics of the Assabet River reflect this history. 

The area has become more suburban over time with a rapid 

increase in the number of single-family homes, roads, and 

commercial developments. Rapid develop­ment in this area 

of Massachusetts has strained the basin’s water resources by 

diminishing flow and affecting water quality.

2 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Figure 1. The Assabet River Basin in central Massachusetts.

71 ̊36'

42 ̊18'

42 ̊24'

42 ̊30'

71 ̊24'

42 ̊36'

Assabet River

Assabet

River

EXPLANATION

EXPLANATION

MASSACHUSETTS

42o00'

42o30'

73o00' 72o

00'

71o00'

70o00'

41o30'

CAPE COD 

BAY

ATLANTIC

OCEAN

NANTUCKET

SOUND

0 50 KILOMETERS

0 50 MILES

BASIN BOUNDARIES

HUDSON BERLIN

NORTHBORO

WESTBORO

BOLTON

STOW

HARVARD

LITTLETON

CLINTON

SHREWSBURY

GRAFTON

MARLBORO

MAYNARD

SUDBURY

CONCORD

BOXBORO ACTON

WESTFORD

CARLISLE

STUDY BASIN

BOYLSTON

BASIN BOUNDARY

TOWN BOUNDARY

WASTEWATER DISCHARGE

DAM

0 1 2 3 4 5 MILES

0 1 3 2 4 6 5 7 8 KILOMETERS

From USGS and MassGIS data sources, Massachusetts State Plane 

Coordinate System, Mainland Zone. 

Powdermill (Figure 14)

Ben Smith (Figure 13)

Gleasondale (Figure 12)

Hudson (Figure 11)

Allen Street (Figure 10)

Aluminum City (Figure 9)

A-1

The Assabet River and its Sediments 3
In spite of the Assabet River’s diversity of wildlife, 

popularity for recreational activities, and recent designation as 

part of a Wild and Scenic River basin, it is a highly eutrophic 

system, primarily because of nutrient enrichment from the 

effluents of wastewater-treatment plants. The extent of eutrophication is evident in the impounded reaches, which support 

substantial growth of rooted and floating macrophytes. 

During the summer and early fall of 2003, the U.S. 

Geological Survey (USGS), in cooperation with the 

Massachusetts Department of Environmental Protection 

(MDEP) and the U.S. Environmental Protection Agency 

(USEPA), mapped the extent and studied the chemical properties of sediments in six impoundments in the Assabet River 

Basin. The USGS also studied the dynamics of phosphorus 

release from sediments in a wastewater-dominated impoundment in Hudson, Massachusetts. This impoundment was one 

of the original six impoundments.

This two-part report provides the results of the assessment of the sediment extent and chemistry in the six impoundments in the Assabet River and describes the results of the 

study of the dynamics of phosphorus release. Obtaining data 

to determine whether there is a relation between the distribution of phosphorus in the sediments and the concentrations of 

phosphorus in the water column was a link between the two 

parts of this study.

Sediment was sampled from the following six impoundments along the Assabet River:

1. Route 20, also known as Aluminum City impoundment (Northborough, built in 1925); 

2. Allen Street impoundment (Northborough, built in 

1900); 

3. Hudson (Washington Street) impoundment (Hudson, 

built in 1860), the site of the phosphorus dynamics 

study; 

4. Gleasondale impoundment (Stow, built in 1924); 

5. Ben Smith impoundment (Maynard, built in 1870); 

and 

6. Powdermill impoundment (Maynard/Acton, built in 

1921). 

The interpretations of bulk-sediment chemistry data in 

this report include results of analyses for volatile organic 

compounds (VOCs), polycyclic (or polynuclear) aromatic 

hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), 

organochlorine pesticides, extractable petroleum hydrocarbons 

(EPH), reactive sulfide, and a selected group of metals and 

other elements, including phosphorus. The concentrations of 

these chemical constituents in the sediments are compared to 

standards for the disposal of dredged hazardous materials; for 

human contact; and for potential effects, including toxicity, on 

aquatic organisms.

The sediment-chemistry data are intended to provide 

managers and environmental regulators with information 

required to make informed choices of the best means for 

improving sediment and surface-water quality in the Assabet 

River Basin. Possible sediment-management options available to water-resource managers considering river restoration 

include: (1) reducing concentrations of phosphorus released 

from treatment plants; (2) dredging sediments (partial or total 

removal); (3) chemical treatment of sediments to prevent phosphorus release; (4) removal or structural modification of dams; 

and (5) making no changes. 

4 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Study Design

To determine the extent and volume of sediments and 

to create maps for sampling-site selection, the impoundment 

bathymetry and sediment thickness for the six impoundments 

affected by wastewater effluent on the Assabet River were 

delineated by manual probing. Representative physical and 

chemical properties of the sediment behind each dam were 

determined from sediment core samples collected at randomly selected sites. Samples were analyzed at laboratories in 

Massachusetts, Rhode Island, and Ontario, Canada. 

Mapping of Bathymetry and Sediment Thickness

Data on water depth and soft-sediment thickness were 

collected by probing manually with an extendible stainlesssteel rod in the reaches behind the six dams (fig. 2). A total 

of 682 manual water-depth and sediment-thickness soundings 

were taken in the six impoundments: 34 at Aluminum City 

dam, 140 at Allen Street, 142 at Hudson, 91 at Gleasondale, 

183 at Ben Smith, and 92 at Powdermill.

A Trimble TSC1 GPS unit was used to record depthsounding coordinates. The Trimble positional data were differentially corrected before being imported as point coverages 

into the geographic information system (GIS) ArcInfo (ESRI, 

2002). Impoundment outlines were created from orthophotos with a resolution of 1:5000 (1/2 meter). An ARC Macro 

Language script positioned the point coverage of the depth 

soundings in the coverage of the river outlines, and a triangular irregular network (TIN) data set (a type of spatial coverage) 

was generated to create preliminary contours of the impoundment bathymetry.

Selection of Sediment-Sampling Sites

Fifty-seven primary sampling sites and 57 matching alternate sampling sites were chosen by using a random-selection 

subroutine within ARC/INFO GIS software (Scott, 1990). The 

number and distribution of sediment-sampling sites among the 

impoundments were determined by the relative size of each 

impoundment, by the locations of depositional environments, 

and by the locations of possible contamination source areas. 

On the basis of past experience with sediment sampling and 

input from stakeholders, the sampling network was designed 

to collect a sufficient number of samples to represent the 

potential sediment variability within the study area.

Collection of Sediment Cores

To achieve the project objectives of physically and chemically characterizing the bed sediments behind the 6 Assabet 

River impoundments, more than 100 sediment cores were 

collected from the 57 sampling sites. The two cores taken 

from each site were considered to be equally representative of 

the sediment at that site; one core was reserved for analysis 

of organic chemical constituents, and the other for analysis of 

inorganic constituents. At each site, field crews retrieved the 

longest possible soft-sediment core.

The randomly selected sites were identified in the field 

with a GPS unit. If cores could not be retrieved at the primary 

site, an alternate site was used. All coring was done from a 

flat-bottomed john boat equipped with a four-stroke outboard 

motor. All cores were retrieved with a piston corer (Aquatic 

Research Instruments, Hope, Idaho). 

Part 1. Sediment Distribution and Chemistry in Six Impoundments in the Assabet River, Central Massachusetts

Study Design 5
Upon arrival at a sampling location, the field crew 

anchored and braced the boat to provide a stable work platform against any existing wind or current. Driving steel rods 

into the sediment allowed the crew to approximate the maximum possible core length and to mark the sampling station. 

Polycarbonate plastic tubing was cut to the expected core 

length and secured to the core head with the piston in a ready 

position at the foot of the plastic core barrel (fig. 3). Polyvinyl 

chloride (PVC) pipe of 1-in. inner diameter was driven into 

the sediment to allow measurement of the total drive depth. 

The corer equipped with an extension rod was positioned at 

the sediment surface adjacent to the PVC pipe, and aligning 

marks were put on both the extension rod and the PVC pipe. 

One crew member held the piston cable in place, while the 

second manually drove the core barrel into the sediment until 

stopped by initial refusal. A 5-lb slide hammer was then used 

to drive the core barrel farther into the sediment until final 

refusal; with the corer and the PVC pipe in this configuration, the distance between the previously aligned marks on 

the aluminum extension rod and the stationary PVC pipe 

represented the total drive depth. The difference between the 

total drive depth and the water depth provided the drive depth 

in the sediment and a way to determine the extent of compaction. The core was extracted with gloved hands and capped 

at both ends with native-water-rinsed polypropylene caps. To 

minimize any losses from the core sampler, the end cap was 

secured to the core tube before the end of the tube broke the 

surface of the water. On the boat, top and bottom polypropylene end caps were secured to the core with vinyl tape and 

the core was labeled. The second core was obtained in the 

same manner from a position less than 1 m from the first site. 

Figure 2. A probe is used to collect data for a map of sediment 

thickness and extent.

Figure 3. A piston corer is prepared for collection of a sediment 

core.

6 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Cores were secured upright in a cooler and kept cool with ice 

for transportation to the USGS MA–RI Water Science Center 

office.

Sample Preparation 

At the MA-RI Water Science Center laboratory, cores 

were placed in 55-gal plastic barrels filled with ice. Cores 

were extruded with a Teflon piston into a clean, half-section 

of a 4-in. diameter, 8-ft polycarbonate tube (figs. 4 and 5). The 

core lengths and lithological data were recorded and photographs were taken. Then, a 5-mL sample for VOC analysis 

was collected with a syringe (fig. 6). The remainder of the core 

was put into a precleaned 25-L Teflon bag which was massaged to thoroughly homogenize the core. A corner of the bag 

was then cut and samples were extruded into labeled glass jars 

for analysis (fig. 7); some of the cores designated for organiccompound analyses were sectioned into thirds before homogenizing to provide some information about variability with 

depth. Cores collected for elemental analysis were split into as 

many as five sections to determine depth variability (table 1). 

Each section was put into a pre-cleaned 1.5-L Teflon bag and 

thoroughly homogenized before extrusion into a labeled plastic Whirl-Pak bag for analysis (fig. 8). All samples were stored 

at 4oC until transport to their respective laboratories. Grainsize samples were extruded into Whirl-Pak bags and frozen for 

possible analysis at a later date. 

Analytical Methods

Laboratory analyses included VOCs, PAHs, PCBs, 

organochlorine pesticides, EPH, reactive sulfide, and metals. 

The analyte list was chosen to correspond with analytes listed 

in regulations guiding the disposal of sediments.

SGS Canada, Inc., Minerals Services (formerly XRAL 

Laboratories), of Toronto, Ontario, analyzed sediment samples 

for 32 elements (mainly metals) by using inductively coupled 

plasma-emission spectrometry, after the samples were digested 

by aqua regia. Each element analyzed by this method has its 

own reporting level (RL).

The USEPA Region I laboratory in Chelmsford, MA, 

analyzed sediment samples for VOCs by using standard gas 

chromatography/mass spectrometry (GC/MS) techniques (U.S. 

Environmental Protection Agency, 1996a). The methodology 

can quantify the concentrations of 70 compounds in soils or 

sediments. The USEPA laboratory also analyzed sediment 

samples for PAHs (U.S. Environmental Protection Agency, 

2000). The analytical method, which uses GC with mass selective detector, measures concentrations of 16 PAH compounds. 

Nominally, project RLs for PAHs were 0.0017 mg/kg. In 

practice, organic interferences required sample dilutions of up 

to 100 times with actual RLs as high as 0.620 mg/kg. 

Figure 4. A Teflon piston is used to extrude core into a polycarbonate 

tube.

Study Design 7
Figure 5. An extruded core.

Figure 6. A sample is collected for volatile organic compound analysis.

8 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Figure 7. A sample is collected for polychlorinated biphenyl and pesticide 

analyses.

Figure 8. A sample is prepared for metal analysis.

Study Design 9
Map ID Field ID Sample ID Sample depth

(in.)

Aluminum City

AC1 AC4 5 0–16.3

AC2 AC2 7A 0–6.7

7B 6.7–13.4

7C 13.4–20.1

AC3 AC3 6A 0–7.1

6B 7.1–14.2

6C 14.2–21.3

AC4 AC1 8A 0–7.9

8B 7.9–15.7

8C 15.7–23.2

Allen Street

AS5 AS1 1A 0–7.9

1B 11.8–19.7

1C 19.7–27.6

1D 27.6–35.4

AS6 AS3 3A 0–7.9

3B 7.9–15.7

3C 15.7–22.4

AS7 AS2 2A 0–7.9

2B 7.9–15.7

2C 15.7–23.6

2D 23.6–30.7

AS8 AS4 4A 0–7.9

4B 9.8–17.7

4C 20.5–28.3

4D 34.6–42.5

4E 48.8–56.7

Hudson

H9 H1 9 0–10.2

H10 H4 12A 0–7.1

12B 7.1–14.2

12C 14.2–22.0

12D 22.0–30.7

12E 30.7–39.4

H11 H5 13A 0–7.9

13B 7.9–13.8

13C 13.8–19.3

13D 19.3–26.4

H12 H2 11A 0–8.7

11B 8.7–17.3

H13 H6 14A 0–7.9

14AQ 0–7.9

14B 7.9–15.7

14BQ 7.9–15.7

14C 15.7–23.6

14CQ 15.7–23.6

14D 23.6–31.5

Map ID Field ID Sample ID Sample depth

(in.)

Hudson—Continued

H13—Continued

14DQ 23.6–31.5

14E 31.5–38.6

14E 31.5–38.6

14EQ 31.5–38.6

H14 H3 10A 0–9.1

10B 9.1–18.1

H15 H7 15A 0–7.9

15B 7.9–15.7

15C 15.7–23.6

15D 23.6–30.7

Gleasondale

G16 G10 34A 0–7.5

34B 7.5–15.0

34C 15.0–22.8

G17 G2 39A 0–5.9

39B 7.9–15.7

39C 15.7–23.6

39D 23.6–32.7

G18 G5 35A 0–7.9

35B 11.4–19.3

35C 22.8–30.7

35D 34.3–42.1

35E 45.7–53.5

G19 G11 40A 0–7.9

40B 17.3–25.2

40C 34.6–42.5

40CQ 34.6–42.5

40D 52.0–59.8

40E 69.3–77.2

G20 G1 36A 0–7.9

36AQ 0–7.9

36B 7.9–15.7

36C 15.7–23.6

36D 23.6–31.5

36E 31.5–39.4

G21 G7 44 0–7.1

G22 G8 41A 0–8.3

41B 8.3–16.5

41C 16.5–24.4

G23 G4 37A 0–8.7

37B 8.7–16.9

37C 16.9–25.2

37D 25.2–33.5

G24 G6 42A 0–7.9

42B 11.8–19.7

G25 G12 45 0–7.1

Table 1. Identifiers and depths for samples collected in six impoundments in the Assabet River, Massachusetts. 

[Map ID: The identifier associated with a sampling site on a map (figs. 9–14). Field ID: core identifier. Sample ID: Identifier for a sample collected from a 

particular core, arranged alphabetically from the top of the core, with Q designating a replicate sample. in., inches]

10 Sediment Studies in the Assabet River, Central Massachusetts, 2003
MapID Field ID Sample ID Sample depth

(in.)

Gleasondale—Continued

G26 G9 38A 0–8.7

38B 8.7–16.9

38C 16.9–25.5

G27 G3 43 0–9.8

Ben Smith

BS28 BS1 16A 0–4.7

16B 4.7–9.4

BS29 BS6 18A 0–5.9

18B 5.9–11.8

18C 11.8–18.1

BS30 BS2 17A 0–6.3

17B 6.3–13.0

17C 13.0–19.7

17D 19.7–26.0

17E 26.0–34.6

BS31 BS7 19A 0–9.4

19AQ 0–9.4

19B 9.4–18.9

19BQ 9.4–18.9

19C 18.9–28.7

19CQ 18.9–28.7

19D 28.7–36.6

19DQ 28.7–36.6

19E 36.6–44.5

19EQ 36.6–44.5

BS32 BS8 20A 0–7.9

20B 16.5–24.4

20C 33.1–40.9

20D 45.7–57.5

20E 66.1–74.0

BS33 BS3 21A 0–7.9

21B 7.9–15.7

21C 15.7–23.6

21D 23.6–31.5

21E 31.5–39.4

BS34 BS4 22A 0–7.9

22B 7.9–15.7

22C 15.7–23.2

BS35 BS9 23A 0–7.9

23B 7.9–15.4

23C 15.4–22.0

BS36 BS5 27A 0–7.1

27B 18–35

27C 13.8–20.5

27D 20.5–27.2

MapID Field ID Sample ID Sample depth

(in.)

Ben Smith—Continued

BS37 BS10 29A 0–7.9

29B 7.9–17.7

29C 15.7–24.0

BS38 BS11 26A 0–7.9

26B 7.9–15.7

26C 15.7–23.6

26D 23.6–31.5

26E 31.5–40.6

BS39 BS13 25A 0–6.7

25B 6.7–13.0

BS40 BS12 24A 0–7.9

24B 7.9–15.7

24C 15.7–23.2

BS41 BS14 28A 0–8.7

28AQ 0–8.7

28B 8.7–17.3

28BQ 8.7–17.3

BS42 BS16 33A 0–7.5

33B 7.5–15.0

BS43 BS17 30A 0–7.1

30B 7.1–14.2

30C 14.2–21.3

30D 21.3–28.3

30E 28.3–35.4

BS44 BS15 31A 0–12.6

31B 12.6–22.4

BS45 BS18 32A 0–7.9

32B 7.9–15.7

Powdermill

P46 P1 48 0–10.2

48Q 0–10.2

P47 P3 49 0–5.5

P48 P2 46A 0–7.9

46B 7.9–15.7

46C 15.7–20.9

P49 P4 47 0–8.3

P50 P5 52A 0–7.9

52B 9.8–17.7

52C 19.3–27.2

52CQ 19.3–27.2

52D 28.7–36.6

52E 38.2–46.1

P51 P8 55A 0–8.7

55AQ 0–8.7

55B 8.7–17.3

55C 17.3–25.6

Table 1. Identifiers and depths for samples collected in six impoundments in the Assabet River, Massachusetts.— Continued

[Map ID: The identifier associated with a sampling site on a map (figs. 9–14). Field ID: core identifier. Sample ID: Identifier for a sample collected from a 

particular core, arranged alphabetically from the top of the core, with Q designating a replicate sample. in., inches]

Study Design 11
The EPH method, designed to assess exposure to petroleum hydrocarbons that may cause human health hazards 

(MDEP, 2002, 2004), measures the concentrations of aliphatic 

and aromatic hydrocarbons in soils or water by GC with a 

flame-ionization detector. Some of the petroleum products 

that this method may detect include kerosene, fuel oils #2, #4, 

and #6, diesel oil, jet fuel, and some lubricating oils. These 

are essentially the same compounds targeted by the USEPA’s 

PAH analyses, but the EPH-method RLs are 0.5 mg/kg, which 

is higher than the 0.0017 mg/kg for the PAH analyses. New 

England Testing Laboratory, Providence, RI, performed the 

EPH analyses reported here.

The reactive sulfide method determines the amount of 

the highly corrosive and toxic vapor hydrogen sulfide which 

is released when sediment is placed in contact with acid. At 

present, Massachusetts has no regulatory standard, but the 

State’s policy calls for lime stabilization of dredged sediments 

with reactive sulfide concentrations greater than 500 parts per 

million (500 mg/kg). New England Testing Laboratory used a 

standard procedure (U.S. Environmental Protection Agency, 

1996b) with a reporting level of 5 mg/kg to analyze the 

sediments in this study for reactive sulfide. 

Alpha Analytical, Inc., Westborough, MA, used capillarycolumn gas chromatography (U.S. Environmental Protection 

Agency, 1996c, d) to analyze sediment samples for PCBs and 

organochlorine pesticides. The RLs for PCBs (0.017 mg/kg) 

and organochlorine pesticides (0.0008 mg/kg) were also 

affected by sample dilutions that may have raised the RLs by a 

factor of as much as 100. 

Quality Assurance and Quality Control

Several precautionary steps were taken to ensure that 

sediment-sample collection and processing did not introduce 

contamination to the samples. In the field, sediment cores 

were collected with freshly manufactured plastic sleeves that 

were rinsed with ambient water at the site before core collection. Cores were capped and sealed at both ends in the field 

and returned to the Water Science Center office in plastic 

containers for processing. The cores were extruded (fig. 4) 

onto a large-diameter plastic tube that had been cut in half 

Table 1. Identifiers and depths for samples collected in six 

impoundments in the Assabet River, Massachusetts.—Continued

[Map ID: The identifier associated with a sampling site on a map (figs. 

9–14). Field ID: core identifier. Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the 

core, with Q designating a replicate sample. in., inches]

MapID Field ID Sample ID Sample depth

(in.)

Powdermill—Continued

P51—Continued

55D 25.6–33.9

P52 P6 53A 0–7.9

53B 15.4–19.3

53C 26.8–34.6

53D 42.1–50.0

53DQ 42.1–50.0

53E 57.5–65.4

P53 P9 54A 0–8.7

54B 8.7–16.9

54C 16.9–25.2

54CQ 16.9–25.2

P54 P10 56A 0–7.9

56B 7.9–15.7

56BQ 7.9–15.7

56C 15.7–23.6

P55 P11 51A 0–7.9

51B 9.8–17.7

51BQ 9.8–17.7

51C 19.7–27.6

51D 29.5–37.4

51E 29.8–47.2

P56 P7 50A 0–7.9

50AQ 0–7.9

50B 15.4–23.2

50C 30.7–38.6

50D 46.1–53.9

50E 61.4–69.3

P57 P12 57 0–10.6

57Q 0–10.6

12 Sediment Studies in the Assabet River, Central Massachusetts, 2003
lengthwise, thoroughly cleaned with methanol and hydrochloric acid, and rinsed with distilled water. All parts of the 

extrusion apparatus were washed and rinsed with distilled 

water before samples were collected from a fresh core. All 

samples were handled with fresh latex gloves that were always 

discarded between consecutive collections of samples and frequently during the processing of samples from a single core. 

Reproducibility of the sample homogenization process 

was tested with replicate analyses of approximately 10 percent 

of the samples of each type. Relative Percent Difference 

(RPD) calculations based on the results for replicate sample 

pairs rarely exceeded the 50-percent limit. The single pair 

of PAH-analysis results that exceeded the 50-percent RPD 

limit was from environmental and quality-control samples 

that exhibited systematic differences. These two samples, 

however, were handled differently in the analytical laboratory (one sample was diluted, whereas the other was not), and 

the individual sample with low PAH concentrations also had 

low percent recoveries of surrogates that would account for 

the differences. Other RPDs exceeding the 50-percent limit 

were distributed randomly among impoundments and within 

samples. Of the exceedances for the six sample pairs that had 

RPD limit exceedances, four were represented by a single 

element (three pairs of measurements of molybdenum at concentrations close to its reporting level and one pair of measurements of chromium). The RPD values that exceeded the RPD 

limit in two sets of organic-compound samples are attributable 

to differences in sample dilution at the analytical laboratory. 

The replicate-sample results showed that the sampling process 

produced consistently representative data for this study.

Sediment Thickness and Bathymetric 

Maps

Although sediment-thickness data associated with the 

core sites were not used to create the sediment maps, data 

obtained by manual probing indicate the core sites where sediment thicknesses and water depths were greatest. Sedimentcore lengths were generally less than the lengths measured by 

manual probing because a thin, pointed metal rod can penetrate sediments farther than a 2 to 3-in.-diameter flat-edged, 

plastic tube. 

Data collected by manual probing were used to determine 

the water-depth contour lines on the bathymetric maps of the 

impoundments (figs. 9 to 14). The maximum water depth was 

least in the Aluminum City impoundment (3.9 ft) and greatest 

in the Gleasondale impoundment (11 ft). Water depths were 

not related to a fixed datum and could change with streamflow.

The Aluminum City impoundment (fig. 9) was found to 

be rock-bottomed (rip-rapped) near the dam and to have primarily rock and sand refusal in the upstream reach. Its thickest 

sediments were measured near the dam (core site AC4, 3.3 ft) 

and close to the farthest upstream core site (AC1, 2.4 ft). The 

greatest water depth measured at the time of sediment mapping was 3.9 ft. 

The thickest sediment deposits in the Allen Street 

impoundment (fig. 10) were measured near core sites AS6 and 

AS8 (11 ft). Probe refusal at the Allen Street impoundment 

was caused by sand and gravel within the channels upstream 

of AS5 and the area immediately downstream from the Allen 

Street bridge. The wide depositional area of the impoundment 

generally had a refusal caused by fine sand, silt, and clay. A 

maximum water depth of 8.2 ft was measured above thin sediment deposits between sites AS6 and AS8.

In Hudson, the impoundment’s thickest sediment (7.5 ft) 

was measured in the area north of H12 (fig. 11); sediment 

thicknesses exceeding 6 ft were also measured in the vicinity 

of H15. The bottom of the Hudson impoundment was characterized by sand and gravel in the river channel and fine materials in lateral depositional areas. Water depths reached more 

than 10 ft near in the channel leading to the dam.

The deepest manual probes in Gleasondale sediments 

were made in the upstream areas (fig. 12) in the general vicinity of G18, G19, and G20, where they penetrated farther than 

18 ft without reaching refusal; however, the probes may have 

penetrated preimpoundment sediment deposits. The downstream reach had a relatively steep gradient that may have 

caused sediment scouring and shallow sediment thicknesses. 

Water depths approached 11 ft near G22.

Sediment Thickness and Bathymetric Maps 13
0.28

0.23

0.22

10

0

20

30

40

0.13 10

0

20

30

40

50

0.19 

0.17 

10 0.16

0

20

30

40

0.17

0.12

10

20

40

30

0

2

1

3

1

2

3

AC 1

AC 1

AC 2

AC 4

AC 3

35%

6%

26%

HA10 HA28 CS10

35%

6%

26%

HA10 HA28 CS10

35%

6%

26%

HA10 HA28 CS10

35%

50%

38%

HA10 HA28 CS10

71O38'10" 71O

38'05"

42O19'10"

42O19'15"

0

0 10 20 METERS

50 100 FEET

SEDIMENT 

THICKNESS—In feet

0 1

1 2

3 4

4 5

5 6

6 7

>7

2 3

EXPLANATION

HA10

CS10

HA28

TRACE ELEMENTS

LEVELS MEASURED WITHIN THE

SURFICIAL SEDIMENTS

Greater than PEL

Greater than TEL but less than PEL

Less than TEL

Lead

Nickel Chromium Zinc Copper

Arsenic Cadmium

TOXICITY Incidence of toxicity, in percent

SAMPLING SITE

3

2

4

5

6

7

Hyalella azteca

10- to 14-day tests

Hyalella azteca

28- to 42-day tests

Chironomus spp.

10- to 14-day tests

LINE OF EQUAL 

WATER DEPTH—

in feet. Interval 

1 foot

1

AC 1DEPTH, IN INCHES

Maximum

sediment 

depth probed

TOTAL

PHOSPHORUS

50

60

10

0

20

30

40

Total bulk-sediment

phosphorus, in 

percent

Base map from MassGIS digital orthophoto,

NAD 83

Route 20

Aluminum City

Dam

Figure 9. Sediment thickness, phosphorus bulk-sediment profiles, exceedances of TEL (threshold effect level) 

and PEL (probable effect level) guidelines for toxic trace elements, and potential for sediment toxicity to aquatic 

life from cores collected in Aluminum City impoundment in Northborough, Massachusetts, 2003.

14 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Figure 10. Sediment thickness, phosphorus bulk-sediment profiles, exceedances of TEL (threshold effect level) 

and PEL (probable effect level) guidelines for toxic trace elements, and potential for sediment toxicity to aquatic 

life from cores collected in Allen Street impoundment in Northborough, Massachusetts, 2003.

71o38' 71o

37'50"

42o19'40"

42o19'50"

35%

50%

38%

HA10 HA28 CS10

35%

6%

26%

HA10 HA28 CS10

35%

50%

38%

HA10 HA28 CS10

35%

6%

26%

HA10 HA28 CS10

3

2

1

5

6

4 3

4

3

4

4

4 3

2

2

2

1

3

1

2

1

6

0

10

20

30

40

50

60

70

0.06 

0.05 

0.05 

0

10

20

30

40

50

0.08 

0.21

0.18 

0

10

20

30

40

0.07

0.21

0.08

0.07

107

0

10

20

30

40

50

60

0.19

0.31

0.11

0.28

0.06 

95

AS 8

AS 7

AS 6

AS 5

0

0 30 60 METERS

150 300 FEET

SEDIMENT 

THICKNESS—In feet

0 1

1 2

3 4

4 5

5 6

6 7

>7

2 3

EXPLANATION

HA10

CS10

HA28

TRACE ELEMENTS

LEVELS MEASURED WITHIN THE

SURFICIAL SEDIMENTS

Greater than PEL

Greater than TEL but less than PEL

Less than TEL

Lead

Nickel Chromium Zinc Copper

Arsenic Cadmium

TOXICITY Incidence of toxicity, in percent

AS 8 SAMPLING SITE

3

2

4

5

6

7

Hyalella azteca

10- to 14-day tests

Hyalella azteca

28- to 42-day tests

Chironomus spp. 

10- to 14-day tests

LINE OF EQUAL

WATER DEPTH—

in feet. Interval

1 foot

1

DEPTH, IN INCHES

Maximum

sediment 

depth probed

TOTAL

PHOSPHORUS

50

60

10

0

20

30

40

Total bulk-sediment

phosphorus, in 

percent

Base map from MassGIS digital orthophoto,

NAD 83

Allen Street

Dam

Allen Street

Aqueduct

Hudson Street

Sediment Thickness and Bathymetric Maps 15
Figure 11. Sediment thickness, phosphorus bulk-sediment profiles, exceedances of TEL (threshold effect 

level) and PEL (probable effect level) guidelines for toxic trace elements, and potential for sediment toxicity to 

aquatic life from cores collected in Route 85 impoundment in Hudson, Massachusetts, 2003.

1

2

1

1

2

2

2

3

1

3

3

3

3

4

5

5

4

4 4

6 7

3

4

5

6

7

8

8

8

1 1

2

3

4

5

3

2

6

7

H 15

H 14

H 13

H 12

H 11

H 10

35%

6%

26%

HA10 HA28 CS10

50%

100%

HA10 HA28 CS10

49%

35%

6%

HA10 HA28 CS10

26%

35%

6%

26%

HA10 HA28 CS10

HA10 HA28 CS10

41%

9 %

43%

35%

6%

26%

HA10 HA28 CS10

35%

6%

26%

HA10 HA28 CS10

0.11

0.09

0.04

0.11

0.05

10

20

30

40

50

0

0.13

0.06

0.06

0.10

0.11

10

20

0

*

10

0

20

30

40

50

0.32

0.16

0.09

0.06

0

10

20

30

0.05

0.04

0

10

20

30

0.14

0.04

0

10

20

30

40

50

60

70

97

0

10

20

30

40

0.09

0.04 0.05 0.02

0.06

H 10

0

0 60 120 METERS

300 600 FEET

SEDIMENT 

THICKNESS—In feet

0 1

1 2

3 4

4 5

5 6

6 7

>7

2 3

EXPLANATION

HA10

CS10

HA28

TRACE ELEMENTS

LEVELS MEASURED WITHIN THE

SURFICIAL SEDIMENTS

Greater than PEL

Greater than TEL but less than PEL

Less than TEL

Lead Nickel Chromium Zinc CopperArsenic Cadmium

TOXICITY Incidence of toxicity, in percent

SAMPLING SITE

3

2

4

5

6

7

Hyalella azteca

10- to 14-day tests

Hyalella azteca

28- to 42-day tests

Chironomus spp.

10- to 14-day tests

LINE OF EQUAL 

WATER DEPTH—

in feet. Interval 

1 foot

6

DEPTH, IN INCHES

Maximum

sediment 

depth probed

TOTAL

PHOSPHORUS

50

60

10

0

20

30

40

Total bulk-sediment

phosphorus, in

percent

71O34'45" 71O

34'30" 71O

34'15"

42O23'

42O23'15"

42O23'30"

Base map from MassGIS digital orthophoto,

NAD 83

Hudson

Dam

Route 85

16 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Figure 12. Sediment thickness, phosphorus bulk-sediment profiles, exceedances of TEL (threshold effect level) and PEL (probable effect level) guidelines for toxic 

trace elements, and potential for sediment toxicity to aquatic life from cores collected in Gleasondale impoundment in Stow, Massachusetts, 2003.

00

500 FEET

150 METERS

Base map from MassGIS digital orthophoto,NAD 83

1

1

2

2

3

5

765

3

3

1

2

4

4

2

1

32

1110

1

6

6

6

6

6

6

102030

0 0.08

0.04

0.06

102030

0.08 0

*

10

0.02 0

10203040

0 0.04

0.03

0.04

0.03 *

10203040506070

0 0.17 

0.14

0

0.0

.07

9

0.12 

0

1020

30

40506070

0.67 

0.19 

0.16

0

0

.02

.07

84 *

0

1020

0.07

95 *

102030

0.05

0.02

0

*

102030

0.07

0.06

0.04 *

0

102030

0.71

0.19

0.10 *

0

1020304050

0.04

0

*

0.06

1020304050

0.04

0.03

0.09

0

*

G 27

6 G 2 G 25

G 24

G 23

G 22

21 G G 2 

G 1 

G 1

7

6

HA10 CS10 HA28

78%

100%

86%

50%

100%

49%

35%

35%

35% 6%

6%

6%

26%

26%

26%

35%

6%

26%

HA10 CS10 HA28

HA10 CS10 HA28

HA10 CS10 HA28

HA10 CS10 HA28

HA10 CS10 HA28

35%

6%

26%

HA10 CS10 HA28

HA10 CS10 HA28

20%

10%

18%

35%

6%

26%

HA10 CS10 HA28

6%

26%

HA10 CS10 HA28

HA10 CS10 HA28

20%

10%

18%

35%

6%

26%

HA10 CS10 HA28

35%

SEDIMENTTHI

CKNESS

—In feet

0 11 23 4

4 55 66 7>7

2 3

EXPLANATION

HA10CS10HA28

TRA

CE ELEMENT

S

LEVELS MEASURED WITHIN THESURFICIAL SEDIMENTS

Greater than PELGreater than TEL but less than PELLess than TEL

LeadNickel Zinc Chromium

Copper

Arsenic Cadmium

T

OXI

CIT

Y Incidence of toxicity, in percent

SAMPLIN

G

SITE

234

567

Hyalella azteca10- to 14-day testsHyalella azteca28- to 42-day testsChironomus spp.10- to 14-day tests

LINE 

OF EQUAL

WATER DEPTH

—

in feet. Interval1 foot

6

G 18

S DEPTH, IN INCHE Maximum sediment 

depth probed

T

OTAL

PHOSPH

O

RUS

15060

0

0

203040

Total bulk-sedimentphosphorus, inpercent

2

71O32' 71O31'50" 71O31'40"

42O24'25"42O24'30"42O24'35"

Gleasondale

Dam

Sediment Thickness and Bathymetric Maps 17
2

2

2

2

2

2

2

2

2

4

4

4

6

4

4

6

4

4

6 6

6

6

8

8

2

2

2

4

4

2

4

6

8

6

4

8

8

Crow Island

71o30' 71o

29'30" 71o

29' 

42o25'

42o25'30"

7

BS

BS 35

BS 34

BS 33

BS 32

BS 31

BS 30

BS 28

0

0

10

20

0.06

0.04

10

20

30

0.15

0.14

0.06

0.18

0.04

0.03

0.17

0.13

0.06

0.07

0.03

0.05

0.02

10

20

30

0.09

0.03

< 0.01

35%

6%

26%

HA10 HA28 CS10

35%

6%

26%

HA10 HA28 CS10

50%

100%

HA10 HA28 CS10

49%

20%

10%

18%

HA10 HA28 CS10

50%

100%

HA10 HA28 CS10

49%

HA10 HA28 CS10

35%

50%

38%

HA10 HA28 CS10

35%

50%

38%

35%

6%

26%

HA10 HA28 CS10

35%

6%

26%

HA10 HA28 CS10

35%

6%

26%

HA10 HA28 CS10

0

0.16

0.13

0.11

0.24

10

20

30

40

50

0

40

0.20

0.17

0.12

0.08

0.06

10

20

30

50

60

70

0

0.86

0.29

0.06

0.08

0.06

10

20

30

40

50

60

70

0

0.18

0.09

0.07

0.05

0.06

10

20

30

40

50

0

10

20

30

0

10

20

30

40

0

10

20

30

0

Base map from MassGIS digital orthophoto,

NAD 83

18 Sediment Studies in the Assabet River, Central Massachusetts, 2003
2

4 4

6

2

6

2

2

2

8

8

6

6

6

4

10

8

6

8 8

2 2 2

4

4

2

8

71o28'30" 71o

28'

S 45

BS 43 BS 43

42

B

BS 40

9

BS 38

10

20

30

40

50

0.14

0.12

0.09

0.02

0.05

0.07

0.06

0.08

0.04

0.05

0.04

0.06

0.07

0.02

0.03

0.02

0.05

17%

13%

16%

HA10 HA28 CS10

20%

10%

18%

HA10 HA28 CS10

35%

6%

26%

HA10 HA28 CS10

35%

6%

26%

HA10 HA28 CS10

35%

6%

26%

HA10 HA28 CS10

50%

100%

HA10 HA28 CS10

49%

35%

6%

26%

HA10 HA28 CS10

29%

4%

19%

HA10 HA28 CS10

0

0.34

0.20

0.13

0.06

0.10

10

20

0

10

20

30

40

50

60

70

80

10

20

30

10

20

30

10

20

30

40

0

0

0

0

10

20

30

40

0

0

10

20

30

40

BS 44

SEDIMENT

THICKNESS—In feet

0 1

1 2

3 4

4 5

5 6

6 7

>7

2 3

EXPLANATION

HA10

CS10

HA28

TRACE ELEMENTS

LEVELS MEASURED WITHIN THE

SURFICIAL SEDIMENTS

Greater than PEL

Greater than TEL but less than PEL

Less than TEL

Lead

Nickel Chromium Zinc Copper

Arsenic Cadmium

TOXICITY Incidence of toxicity, in percent

SAMPLING SITE

3

2

4

5

6

7

Hyalella azteca

10- to 14-day tests

Hyalella azteca

28- to 42-day tests

Chironomus spp. 

10- to 14-day tests

LINE OF EQUAL

WATER DEPTH—

in feet. Interval

2 feet

6

DEPTH, IN INCHES

Maximum

sediment 

depth probed

TOTAL

PHOSPHORUS

50

60

10

0

20

30

40

Total bulk-sediment

phosphorus, in 

percent

0

0 300 METERS

1,000 FEET

Ben Smith

Dam

Routes 117/62

Figure 13. Sediment thickness, phosphorus bulksediment profiles, exceedances of TEL (threshold effect level) and PEL (probable effect level) 

guidelines for toxic trace elements, and potential 

for sediment toxicity to aquatic life from cores 

collected in Ben Smith impoundment in Maynard, 

Massachusetts, 2003.

Sediment Thickness and Bathymetric Maps 19
Figure 14. Sediment thickness, phosphorus bulk-sediment profiles, exceedances of TEL (threshold effect level) and PEL (probable effect level) guidelines for toxic 

trace elements, and potential for sediment toxicity to aquatic life from cores collected in Powdermill impoundment in Maynard and Acton, Massachusetts, 2003.

Base map from MassGIS digital orthophoto,NAD 83

2

1

3

3

2

2

5

6

4

1

7

6

8

5

5

4

3

2

3

1 2

3

4

6

7

7

6

5

4

3

2

1

5

50%

100%

HA10 CS10 HA28

49%

50%

100%

HA10 CS10 HA28

49%

35%

6%

26%

HA10 CS10 HA28

35%

50%

38%

35%

6%

26%

HA10 CS10 HA28

35%

6%

26%

HA10 CS10 HA28

20%

10%

18%

HA10 CS10 HA28

HA10 CS10 HA28

41%

9 %

43%

HA10 CS10 HA28

68%

9 %

1%

35%

6%

26%

HA10 CS10 HA28 HA10 CS10 HA28

35%

50%

38%

HA10 CS10 HA28

HA10 CS10 HA28

41%

9 %

43%

71O26'30" 71O26'15" 71O26'

42O26'15"

42O26'30"

2

55 P 

P 54

P 51

P 49

P 48

P 50

P 47

P 5

P 53

P 57

P 56

10203040

*

0.30

0.16

0.32

124

0

*

1020304050607080

*

0.12 0.04

0.31 0

*

10203040506070

*

0.09

0.31

0.17

0.18

0.06

138

0

*

102030405060

*

0.18

0

0.13

.15

0.05

0

*

10203040506070

0.26

0.09

0.07

0.28

0.13

12

0

0 10

20304050607080

*

0.05 0

*

102030

40

5060

7080

0.04

0.03

0.15 0

0

102030

0.10

10203040506070

*

0.04

0.

0

04

.10 

0.05

0.08 

158 *

0

0.54

0.37

10203040506070

101

0.13

0.08

0.06

0

10203040506070

*

0. 06 0

10203040

0.09

78

0

0

0 150 300 METERS

500 1,000 FEET

SEDIMENTTHI

CKNESS

—In feet

0 11 23 4

4 55 66 7>7

2 3

EXPLANATI

O

N

HA10CS10HA28

TRA

CE ELEMENT

S

LEVELS MEASURED WITHIN THESURFICIAL SEDIMENTS

Greater than PELGreater than TEL but less than PELLess than TEL

LeadNickel Zinc Chromium

Copper

Arsenic Cadmium

TOXI

CIT

Y Incidence of toxicity, in percent

SAMPLIN

G

SITE

234

567 IN INCHES , EPTH D Maximum sediment 

depth probed

T

OTAL

PHOSPH

ORU

S

105060

0

203040

Total bulk-sedimentphosphorus, in percent

Hyalella azteca10- to 14-day testsHyalella azteca28- to 42-day testsChironomus spp.10- to 14-day tests

LINE OF EQUALWATER DEPTH

—

in feet. Interval1 foot

6

P 54

Powdermill

Dam

Route 62

Wastewater

Treatment Plant

20 Sediment Studies in the Assabet River, Central Massachusetts, 2003
The elongated Ben Smith impoundment was characterized by extensive, thick sediment deposits in the vicinity of 

Crow Island (fig. 13). The probe reached through more than 

15 ft of sediment at several places and more than 24 ft near 

BS32. The bottom of the narrow channel section between 

BS34 and BS41 was sandy with finer materials distributed 

along the lateral edges. In the vicinity of the dam, the bottom 

materials were predominantly coarse sand and gravel. Water 

depths exceeded 8 ft near the dam.

The Powdermill impoundment was characterized by having a narrow, rocky channel upstream from P49. Sediments 

were distributed uniformly throughout the main body of the 

impoundment, with the thickest sediments approximately 

along the impoundment’s midline (fig. 14). Sandy conditions 

dominated the impoundment’s bottom. Water depths were 

more than 8 ft just upstream of the dam.

Ben Smith impoundment had the greatest volume of sediment and Aluminum City the least, as calculated by the TIN 

computer program. In decreasing order, the impoundments’ 

sediment volumes were: Ben Smith (580,000 m3), Powdermill 

(120,000 m3), Gleasondale (67,000 m3), Hudson (55,000 m3), 

Allen Street (42,000 m3), and Aluminum City (380 m3). These 

sediment-volume estimates may include some preimpoundment material, and thus may overestimate the amount of 

impounded sediment. 

Sediment Chemistry of the Assabet 

River Impoundments

The concentrations of metals detected were compared 

among the impoundments and with results from analyses 

of the chemistry of sediments in other New England rivers 

(Chalmers, 2002; Robinson and others, 2004). The results 

were also compared with sediment-quality guidelines (table 2) 

related to 1) potential effects on freshwater organisms, 2) 

dangerous levels for human contact, and 3) permitted levels for reuse (disposal) in landfills. The potential effects on 

freshwater organisms are further organized into three groups: 

a) threshold effect level (TEL), the concentration below which 

adverse effects are rarely observed; b) probable effect level 

(PEL), the concentration above which adverse effects are commonly observed; and c) probable effect concentration (PEC), 

the concentration above which adverse effects are expected. 

In general, the PEC is greater than the PEL; the exception is 

Cu. The TEL and PEL are used in discussions of the effects 

of metals on biota and the PEC is used in discussions of the 

combined effects of metals, PAHs, and PCBs on biota.

Elemental Analyses

Dividing the results of the elemental analyses performed 

by SGS Canada Inc., Minerals Services, into three categories 

— phosphorus (as a bulk-sediment analyte), toxic metals, and 

other elements – groups the data in a meaningful way for efficient interpretation. The vertical distribution of phosphorus in 

sediments throughout the study area (table 3) was investigated 

because the sediments may serve as a potential phosphorus 

source. The toxic trace elements constitute a seven-element 

subset of metals (table 14, at back of report) often referred 

to as critical contaminants. The remaining elements are not 

generally considered commonly occurring toxics requiring 

special attention to minimize potential harm to aquatic life or 

humans; their concentrations are reported (table 15, at back of 

report), but not discussed in comparisons among the Assabet 

impoundments.

Phosphorus

A recent survey of stream sediments in New England 

(Chalmers, 2002) reported bulk concentrations of phosphorus 

in samples collected primarily in urban and rural settings. The 

median concentration from that study is slightly higher than 

those for the individual impoundments reported here (table 4). 

The maximum phosphorus concentrations in the Assabet River 

sediments, however, exceeded the maxima reported in the 

other study. 

Bulk-sediment phosphorus concentrations ranged from 

less than the RL of 0.01 percent at site BS37 (subsample from 

approximately 2 ft below the sediment surface) to 0.86 percent 

at site BS32 (surface sample). Throughout the six-impoundment system, the highest phosphorus concentrations generally 

were measured in samples collected closest to the sediment 

surface (table 5; figs. 9 to 14). Three possible explanations for 

this distribution of phosphorus concentrations are: (1) high 

concentrations of phosphorus transported in the water column 

may serve as a continuous supply of phosphorus; (2) rooted 

macrophytes will take up available phosphorus from surficial 

sediments, and as these plants die and decay, all or part of 

their phosphorus will be deposited on the sediment surface, 

where it may once again become available; (3) phosphorus 

may dissolve in deep, anaerobic sediment, diffuse upward, and 

precipitate at the sediment-water interface.

Comparing the means, medians, minima, and maxima of 

concentrations of all samples and of only surface samples from 

the impoundments reveals phosphorus-concentration trends 

with reservoir position (table 5). In the environmental samples, 

the median phosphorus concentration was 0.08 percent and 

the mean concentration was 0.12 percent. Sediment samples 

from Aluminum City, from all impoundments, had the highest 

median (0.17 percent) and mean (0.18 percent) phosphorus 

concentrations. Sediment samples from Aluminum City had 

the lowest maximum (0.28 percent) but the highest minimum 

(0.12 percent) phosphorus concentrations of samples collected 

at all depths from all impoundments. Phosphorus-concentration maxima increased downstream from Aluminum City until 

the Powdermill impoundment, where the maximum concentration decreased. The minima of all samples generally decrease 

in the downstream direction. 

Sediment Chemistry of the Assabet River Impoundments 21
Table 2. Sediment-quality guidelines for freshwater organisms, human contact, and Massachusetts landfill reuse.

[Sources: Massachusetts Department of Environmental Protection, 1995; Breault and others, 2000; Ingersoll and others, 2001. EPH, extractable petroleum 

hydrocarbon; PAH, polycyclic aromatic hydrocarbon; PCB, polychlorinated biphenyl; PEC, Probable Effect Concentration, concentration above which adverse 

effects are expected; PEL, Probable Effect Level, concentration above which adverse effects are commonly observed; TEL, Threshold Effect Level, concentration below which adverse effects are rarely observed; TPH, total petroleum hydrocarbon; μg/kg, micrograms per kilogram; mg/kg, milligrams per kilogram; 

<, actual value is less than value shown; --, no value available]

Constituent or class TEL PEL PEC Human contact Landfill reuse

Total organics (μg/kg)

TPH (~EPH) -- -- -- 800,000 5,000,000

Total PAH -- -- 22,800 -- 100,000

Total PCB 34.1 277 676 2,000 <2,000

Total chlordane 4.5 8.9 17.6 1,000 --

Individual PAHs (μg/kg)

Acenaphthylene -- 88.9 -- 100,000 --

Acenaphthene -- 128 620 1,000,000 --

Anthracene -- 245 845 1,000,000 --

Benzo[a]anthracene -- 385 1,050 -- --

Benzo[k]fluoranthene -- 240 7,000 --

Benzo[g,h,i]perylene -- 170 1,000,000 --

Benzo[a]pyrene -- 782 1,450 700 --

Chrysene -- 862 1,290 7,000 --

Dibenzo[a,h]anthracene -- 135 -- 700 --

Fluoranthene -- 2,355 2,230 1,000,000 --

Fluorene -- 144 536 1,000,000 --

Indeno[1,2,3-cd]pyrene -- -- 200 700 --

Naphthalene -- 391 561 100,000 --

Phenanthrene -- 515 1,170 1,000,000 --

Pyrene -- 875 1,520 700,000 --

Individual PCB Aroclors (μg/kg)

Aroclor-1248 -- -- 30 -- --

Aroclor-1254 -- -- 60 -- --

Aroclor-1260 -- -- 5 -- --

Aroclor-1262 -- -- -- -- --

Aroclor-1268 -- -- -- -- --

Metals (mg/kg)

Arsenic 5.9 17 33 30 40

Cadmium .6 3.53 4.98 30 80

Chromium 37.3 90 111 1,000 1,000

Copper 35.7 197 149 -- --

Lead 35 91.3 128 300 2,000

Nickel 18 35.9 48.6 300 --

Zinc 123 315 459 2,500 --

22 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Map ID Sample ID

Total

phosphorus

(percent)

Aluminum City

AC1 5 0.16

AC2 7A .23

AC2 7B .28

AC2 7C .22

AC3 6A .13

AC3 6B .19

AC3 6C .17

AC4 8A .17

AC4 8B .17

AC4 8C .12

Allen Street

AS5 1A 0.05

AS5 1B .05

AS5 1C .06

AS5 1D .05

AS6 3A .21

AS6 3B .08

AS6 3C .18

AS7 2A .21

AS7 2B .07

AS7 2C .08

AS7 2D .07

AS8 4A .19

AS8 4B .28

AS8 4C .31

AS8 4D .11

AS8 4E .06

Hudson

H9 9 0.06

H10 12A .13

H10 12B .11

H10 12C .10

H10 12D .04

H10 12E .05

H11 13A .09

H11 13B .04

H11 13C .05

H11 13D .02

H12 11A .04

H12 11B .01

H13 14A .11

H13 14B .09

H13 14C .04

Map ID Sample ID

Total

phosphorus

(percent)

Hudson—Continued

H13 14D 0.18

H13 14E .06

H14 10A .14

H14 10B .04

H15 15A .32

H15 15B .16

H15 15C .09

H15 15D .06

Gleasondale

G16 34A 0.08

G16 34B .06

G16 34C .04

G17 39A .04

G17 39B .03

G17 39C .04

G17 39D .03

G18 35A .17

G18 35B .14

G18 35C .12

G18 35D .09

G18 35E .07

G19 40A .67

G19 40B .19

G19 40C .17

G19 40D .07

G19 40E .02

G20 36A .06

G20 36B .06

G20 36C .04

G20 36D .04

G20 36E .05

G21 44 .07

G22 41A .71

G22 41B .19

G22 41C .10

G23 37A .04

G23 37B .03

G23 37C .03

G23 37D .09

G24 42A .05

G24 42B .02

G25 45 .02

G26 38A .07

Map ID Sample ID

Total

phosphorus

(percent)

Gleasondale—Continued

G26 38B 0.06

G26 38C .04

G27 43 .08

Ben Smith

BS28 16A 0.06

BS28 16B .04

BS29 18A .15

BS29 18B .14

BS29 18C .06

BS30 17A .24

BS30 17B .16

BS30 17C .16

BS30 17D .13

BS30 17E .11

BS31 19A .20

BS31 19B .17

BS31 19C .12

BS31 19D .08

BS31 19E .06

BS32 20A .86

BS32 20B .29

BS32 20C .08

BS32 20D .06

BS32 20E .06

BS33 21A .18

BS33 21B .09

BS33 21C .07

BS33 21D .06

BS33 21E .05

BS34 22A .18

BS34 22B .04

BS34 22C .03

BS35 23A .17

BS35 23B .13

BS35 23C .06

BS36 27A .07

BS36 27B .05

BS36 27C .03

BS36 27D .02

Table 3. Concentrations of phosphorus, in percent, in bulk sediment samples from six impoundments in the Assabet River Basin, 

Massachusetts, 2003.

[Map ID: The identifier associated with a sampling site on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged 

alphabetically from the top of the core. <, actual value is less than value shown]

Sediment Chemistry of the Assabet River Impoundments 23
Map ID Sample ID

Total

phosphorus

(percent)

Ben Smith—Continued

BS37 29A 0.09

BS37 29B .03

BS37 29C <.01

BS38 26A .14

BS38 26B .12

BS38 26C .09

BS38 26D .05

BS38 26E .02

BS39 25A .07

BS39 25B .06

BS40 24A .08

BS40 24B .04

BS40 24C .05

BS41 28A .04

BS41 28B .04

BS42 33A .06

BS42 33B .07

BS43 30A .34

BS43 30B .20

BS43 30C .13

BS43 30D .10

BS43 30E .06

BS44 31A .02

BS44 31B .03

BS45 32A .02

BS45 32B .05

Map ID Sample ID

Total

phosphorus

(percent)

Powdermill

P46 48 0.10

P47 49 .09

P48 46A .15

P48 46B .04

P48 46C .03

P49 47 .05

P50 52A .26

P50 52B .28

P50 52C .12

P50 52D .09

P50 52E .07

P51 55A .15

P51 55B .18

P51 55C .13

P51 55D .05

P52 53A .31

P52 53B .18

P52 53C .17

P52 53D .09

P52 53E .06

Map ID Sample ID

Total

phosphorus

(percent)

Powdermill—Continued

P53 56A 0.32

P53 56B .30

P53 56C .16

P54 54A .31

P54 54B .12

P54 54C .04

P55 51A .10

P55 51B .08

P55 51C .05

P55 51D .04

P55 51E .04

P56 50A .37

P56 50B .54

P56 50C .13

P56 50D .08

P56 50E .06

P57 57 .07

Table 3. Concentrations of phosphorus, in percent, in bulk sediment samples from six impoundments in the Assabet River Basin, 

Massachusetts, 2003.—Continued

[Map ID: The identifier associated with a sampling site on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged 

alphabetically from the top of the core. <, actual value is less than value shown]

24 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Table 4. Mean and median concentrations of trace metals in New England stream sediments. 

[mg/kg, milligrams per kilogram; NA, not available; <, actual value is less than value shown; --, no data]

Trace metal

Previous investigations Current (2003) investigations

Robinson and others, 2004 Chalmers, 2002 Aluminum City Allen Street

Mean Median Mean Median Mean Median Mean Median

Aluminum, percent -- -- 5.60 5.65 1.22 1.20 0.13 0.08

Antimony, mg/kg -- -- 2.70 2.40 <5 <5 <5 <5

Arsenic, mg/kg 5.08 2.80 39.2 19.0 10.0 9.00 11.0 11.0

Barium, mg/kg 331 315 506 455 183 180 120 87.5

Beryllium, mg/kg -- -- 3.00 2.80 NA .50 <.5 <.5

Bismuth, mg/kg -- -- NA <1 NA <5 <5 <5

Cadmium, mg/kg -- -- 3.75 2.10 2.00 2.00 NA 1.00

Calcium, percent -- -- 1.34 1.40 .45 .45 .32 .29

Chromium, mg/kg -- -- 134 99.0 336 149 168 154

Cobalt, mg/kg -- -- 19.9 18.0 12.0 12.0 12.0 11.0

Copper, mg/kg 12.1 10.0 121 92.5 397 298 149 55.0

Iron, percent -- -- 4.71 3.90 1.78 1.72 1.61 1.48

Lanthanum, mg/kg 53.7 41.0 50.5 46.0 14.7 15.5 13.3 13.4

Lead, mg/kg 44.1 30.0 229 190 113 82.0 153 150

Magnesium, percent -- -- .70 .71 .38 .36 1.09 1.02

Manganese, mg/kg -- -- 3,500 1,850 465 481 358 280

Molybdenum, mg/kg -- -- 4.85 2.60 5.50 5.50 NA 2.50

Nickel, mg/kg -- -- 43.4 45.0 25.0 24.0 21.0 19.0

Phosphorus, percent -- -- .23 .22 .18 .17 .13 .08

Potassium, percent -- -- 1.46 1.40 .17 .16 .17 .17

Scandium, mg/kg 9.78 9.00 8.71 8.50 1.66 1.60 1.79 1.80

Silver, mg/kg -- -- 2.31 1.50 NA 5.20 NA .35

Sodium, percent -- -- 1.30 1.20 .05 .04 .04 .04

Strontium, mg/kg 157 146 165 170 41.0 43.0 29.0 23.0

Tin, mg/kg -- -- 23.4 18.5 22.9 20.0 25.6 26.0

Titanium, mg/kg -- -- .41 .42 .03 .03 .05 .05

Vanadium, mg/kg 55.5 53.0 76.8 78.5 25.0 26.0 26.0 25.0

Zinc, mg/kg 49.8 43.0 439 295 379 285 295 216

Zirconium, mg/kg 723 535 -- -- 2.79 2.80 2.25 2.00

Sediment Chemistry of the Assabet River Impoundments 25
Table 4. Mean and median concentrations of trace metals in New England stream sediments.—Continued

[mg/kg, milligrams per kilogram; NA, not available; <, actual value is less than value shown; --, no data]

Trace metal

Current (2003) investigations

Hudson Gleasondale Ben Smith Powdermill

Mean Median Mean Median Mean Median Mean Median

Aluminum, percent 1.28 1.27 1.03 1.00 1.25 1.32 1.28 1.21

Antimony, mg/kg <5 <5 <5 <5 <5 <5 NA <5

Arsenic, mg/kg 17.0 9.00 17.0 11.0 22.0 13.0 22.5 14.0

Barium, mg/kg 73.5 43.0 79.6 53.0 79.2 54.0 133 95.5

Beryllium, mg/kg NA .70 NA <.5 NA .70 NA .55

Bismuth, mg/kg <5 <5 <5 <5 <5 <5 <5 <5

Cadmium, mg/kg NA <1 NA <1 NA <1 NA <1

Calcium, percent 1.99 2.15 .31 .29 .27 .27 .43 .29

Chromium, mg/kg 155 155 205 194 177 170 588 322

Cobalt, mg/kg 26.1 22.0 11.0 8.00 1.89 1.62 19.0 13.0

Copper, mg/kg 44.0 14.0 61.0 11.0 49.0 13.0 291 89.2

Iron, percent 1.97 1.66 1.54 1.40 49.3 13.4 1.96 1.94

Lanthanum, mg/kg 22.0 15.3 13.1 12.2 19.6 15.0 15.6 12.9

Lead, mg/kg 95.0 20.0 68.0 16.0 121 16.0 248 171

Magnesium, percent .30 .27 .30 .32 .25 .27 .31 .32

Manganese, mg/kg 412.2 243 320 245 519 439 348 292

Molybdenum, mg/kg NA <.2 4.00 3.00 4.00 4.00 5.81 5.00

Nickel, mg/kg 26.0 22.0 24.0 17.0 25.0 16.0 47.8 30.0

Phosphorus, percent .12 .08 .11 .06 .11 .07 .15 .11

Potassium, percent .30 .25 .15 .16 .09 .08 .14 .14

Scandium, mg/kg 1.99 2.15 1.71 1.70 1.82 1.80 1.76 1.70

Silver, mg/kg NA <.2 NA <.2 NA .20 NA 1.20

Sodium, percent .30 .27 .04 .04 .04 .04 .04 .04

Strontium, mg/kg 24.0 23.0 22.0 21.0 21.0 20.0 8.13 7.00

Tin, mg/kg NA <1 NA <1 .03 .02 67.6 50.5

Titanium, mg/kg .04 .04 .03 .03 .03 .02 .04 .04

Vanadium, mg/kg 155 155 .03 .03 23.0 24.0 28.0 28.0

Zinc, mg/kg 132 63.0 134 37.0 144 37.0 319 163

Zirconium, mg/kg NA 1.60 2.13 2.30 1.41 1.30 2.59 2.15

Table 5. Summary statistics of total bulk phosphorus concentrations in sediment samples from six impoundments in the Assabet 

River Basin, Massachusetts, 2003. 

[All concentrations in percent. <, actual value is less than value shown]

Impoundment

Median,

all

samples

Mean,

all

samples

Maximum,

all

samples

Minimum,

all

samples

Median,

surface

samples

Mean,

surface

samples

Maximum,

surface

samples

Minimum,

surface

samples

Aluminum City 0.17 0.18 0.28 0.12 0.17 0.17 0.23 0.13

Allen Street .08 .13 .31 .05 .21 .17 .21 .05

Hudson .06 .08 .32 .01 .11 .13 .32 .04

Gleasondale .06 .10 .71 .02 .07 .17 .71 .02

Ben Smith .07 .11 .86 <.01 .12 .17 .86 .02

Powdermill .07 .15 .54 .03 .15 .19 .37 .05

26 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Whereas the medians and means of the surface samples 

exhibited no trends with reservoir position, the surface-sample 

phosphorus maxima and minima exhibited trends similar to 

those for all samples. Three of the maximum surface values 

were the same as the maximum values for all samples.

Within some of the individual impoundments, the distribution of sediment phosphorus concentrations varied considerably. At Aluminum City (fig. 9), the smallest impoundment, 

where only four sets of cores were collected, sample concentrations ranged from 0.12 (in the sample from the greatest 

depth at site AC4) to 0.28 percent (at site AC2 in the sample 

from the intermediate depth). At Allen Street (fig. 10), the 

phosphorus concentrations were lowest in the core collected 

farthest upstream (AS5). The farthest downstream core (AS8) 

yielded samples with the highest phosphorus concentrations 

(0.28 and 0.31 percent) measured in this impoundment. In 

the Hudson impoundment (fig. 11), the highest phosphorus 

concentrations, 0.16 to 0.32 percent, were found in upper sediment layers at the most downstream sites (H14 and H15). In 

the Gleasondale impoundment (fig. 12), phosphorus concentrations were generally low, but the surface samples from sites 

G19 and G22 had high concentrations, 0.67 and 0.71 percent, respectively. Of all the impoundments, the Gleasondale 

impoundment had the steepest bed-slope gradient, and the 

downstream sediment thicknesses were not great; it is possible 

that phosphorus-bearing sediments did not settle out in that 

section. At Ben Smith (fig. 13), most of the high phosphorus 

concentrations were found in cores from the upper reaches 

of the impoundment (BS29 to BS35), although a few comparable concentrations were found in cores BS38 and BS43 

from the downstream half of the impoundment. Finally, in the 

Powdermill impoundment (fig. 14), the highest concentrations 

of phosphorus were detected in cores P50 through P54 and 

P56, which were collected between the middle and the downstream end of the impoundment. This area coincides with the 

outfall from the Maynard wastewater-treatment plant.

The maps provide data useful for deciding the extent 

of sediment to dredge, both by surface area and by depth, if 

that option is considered; however, no target bulk-sediment 

phosphorus concentration that would eliminate or minimize 

nuisance plant growth has been established. The data indicate 

that if surficial sediments were removed, the sediments at 

greater depths would still contain phosphorus.

Toxic Trace Elements

The occurrence, distribution, and potential toxic effects 

of seven metals—arsenic (As), cadmium (Cd), chromium (Cr), 

copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn), metals that 

may come from natural weathering, from industrial areas, 

agricultural applications, or automobile traffic (Robinson 

and others, 2004)—were assessed in the surficial sediment 

samples of the six Assabet impoundments (table 14; figs. 9 

to 14). Even at low ambient concentrations, these metals can 

prove harmful to aquatic organisms, because they concentrate through bioaccumulation. Mercury, another commonly 

cited toxic metal, is not considered here because the required 

sample storage and analysis methods for mercury were beyond 

the scope of this investigation. 

Results of recent studies generally bracket the concentrations reported in this study (table 4). Robinson and others 

(2004) studied sediment samples from New England rivers 

whose watersheds represented a broad range of land uses, 

including relatively undisturbed areas. Their results generally 

described streams in which the concentrations of all four (As, 

Cu, Pb, and Zn) of the seven toxic metals reported had lower 

concentrations than were detected in the Assabet sediments; 

exceptions were the high concentrations of strontium and 

zirconium that they reported. In contrast, the mean and median 

concentrations of the seven toxic metals calculated from 

Chalmers’s (2002) data, with the exception of chromium, were 

higher than those determined in the Assabet sediment samples; 

her study focused on streams whose chemistry was strongly 

affected by urban land use, a likely source of metal contamination. In both of these studies, surficial-sediment samples were 

sieved and were not necessarily digested with aqua regia, procedures that could have affected the concentrations measured.

Among the Assabet impoundments, highest average 

concentrations for the seven metals were found in either 

the Aluminum City impoundment (Cd, Cu, and Zn) or the 

Powdermill impoundment (As, Cr, Ni, and Pb); however, sediment samples from many sites in all of the six impoundments 

had high metal concentrations (table 14). At Aluminum City, 

extremely high concentrations of Cr (2,070 mg/kg) and Zn 

(1,220 mg/kg) were found in samples from AC4; samples from 

AC3 and AC2 also had high metal concentrations. The highest metal concentrations in samples from Allen Street were 

detected at AS6, AS7, and AS8; in particular, samples from 

AS8 had high concentrations of Cu (807 mg/kg) and Zn (551 

mg/kg) and samples from AS7 and AS6 had high concentrations of Zn (827 and 487 mg/kg, respectively). In the Hudson 

impoundment, high concentrations of Zn, Pb, Cr, and Cu were 

detected in samples from H10, H11, H13 and H15; Zn, of 

these four metals, was generally found in highest concentrations in samples collected from these sites. In Gleasondale, 

samples from sites G18, G19, and G22 all were characterized 

by high metal concentrations. Sites with high concentrations 

of metals were scattered throughout the elongated Ben Smith 

impoundment (in particular, BS30 to BS35, BS38, and BS43), 

but these sites were most densely distributed in the wide 

upstream section of the impoundment (fig. 13). About half 

the sites within the Powdermill impoundment yielded samples 

of sediment with high metal concentrations: P46, P48, P51 

to P54, and P56. Powdermill yielded 15 detections of metal 

concentrations higher than 1,000 mg/kg.

Concentrations of metals in many of the sediment samples from the six impoundments exceeded sediment-quality 

guidelines (table 2; figures 9 to 14 describe which sediment 

concentrations exceeded the TEL and PEL for surface samples 

only. See tables 3 and 15 to determine exceedances for all 

sediment samples.)

Sediment Chemistry of the Assabet River Impoundments 27
Arsenic concentrations in samples from all of the 

impoundments were generally higher than the TEL of 

5.9 mg/kg. At Aluminum City and Allen Street, the PEL 

was not exceeded; in the Hudson impoundment, the PEL of 

17 mg/kg was exceeded at four of seven sites; the humancontact guideline of 30 mg/kg was exceeded at H11 and H15 

and the landfill-reuse guideline of 40 mg/kg was exceeded at 

H15. At Gleasondale, the PEC guideline for As was exceeded 

at G18-G20 and G22, and the human-contact guideline at 

G18-G20. At Ben Smith, the PEL or PEC was equaled or 

exceeded at all but two sites in at least one sample. In the 

Powdermill impoundment, sites noted previously as having 

sediment samples with multiple, high-concentration detections 

(P48, P50 to P54, and P56) also had As concentrations exceeding either or both of the human-contact and the landfill-reuse 

guidelines.

Most of the Cd analyses returned values below the reporting level of 1 mg/kg, leaving uncertainty about the frequency 

with which the TEL of 0.6 mg/kg was exceeded. The PEL 

of 3.53 mg/kg or the PEC of 4.98 mg/kg was exceeded in 

1 sediment sample at Aluminum City, 2 at Allen Street, 

none at Hudson, 2 at Gleasondale, 7 at Ben Smith, and 11 at 

Powdermill. Human-contact and landfill-disposal guidelines 

for Cd were not exceeded at any of the impoundments. 

Only a single sediment sample had a Cr concentration 

lower than the TEL of 37.3 mg/kg. Most Cr concentrations 

were higher than the PEC of 111 mg/kg. Eight samples from 

sites in the Powdermill impoundment (P48, P51-P54, and P56) 

had Cr concentrations higher than the 1,000 mg/kg maximum 

concentration allowable for human contact and landfill 

disposal.

All but two samples from the Aluminum City impoundment had Cu concentrations higher than the PEL of 

197 mg/kg. Half of the samples from Allen Street had concentrations of Cu less than the PEC of 149 mg/kg and higher 

than the TEL of 35.7 mg/kg. At Hudson, 13 of 23 samples had 

Cu concentrations lower than the TEL and none exceeded the 

PEC. At Gleasondale also, 23 of 37 samples had concentrations less than the TEL; in samples from sites G19 and G22, 

the PEL was exceeded. In the Ben Smith impoundment, the 

PEC was exceeded in samples from five sites (BS30, BS31, 

BS32, BS34, and BS43) and the PEL was exceeded in two 

samples (BS30 and BS32). At Powdermill, the PEL was 

exceeded at the same seven sites (P46, P48, P51, P52, P53, 

P54, and P56).

In sediment samples from all the impoundments, 

sediment concentrations of Ni frequently exceeded the 18 

mg/kg TEL. At Aluminum City and Allen Street, the PEL 

(35.9 mg/kg) was not exceeded. At Hudson, samples from 

sites H10, H13, and H15 had concentrations higher than the 

PEC (48.6 mg/kg). In the Gleasondale impoundment, the PEC 

was exceeded at G19 and G22; at Ben Smith and Powdermill, 

samples from sites BS30, B32, B34, B35, B38, B43, P46, P48, 

and P50 to P56 had samples with concentrations higher than 

either the PEL or PEC.

All the sediment samples collected at Aluminum City 

and Allen Street had Pb concentrations that exceeded the TEL 

(35 mg/kg), and more than half had concentrations that also 

exceeded the PEC (128 mg/kg). More than half of the samples 

from Hudson, Gleasondale, and Ben Smith had Pb concentrations lower than the TEL. Most of the other sample Pb concentrations, however, were higher than the PEC; one sample from 

H10 had a Pb concentration of 324 mg/kg, which exceeded 

the human-contact guideline of 300 mg/kg, and a sample from 

BS38 had a Pb concentration of 3,800 mg/kg—higher than the 

maximum for landfill reuse (2,000 mg/kg). At Powdermill, 12 

of the sites had samples with Pb concentrations that exceeded 

the PEC, and 12 samples had concentrations (at P50 to P54 

and P56) higher than the human-contact guideline; none 

exceeded the landfill-disposal guideline.

The sediment-quality guidelines for Zn are higher than 

the other metals. Nevertheless, all the samples from Aluminum 

City had Zn concentrations in excess of the 123 mg/kg TEL; 

four samples had concentrations that exceeded the PEL 

(315 mg/kg) or PEC (459 mg/kg). Concentrations in 12 of the 

16 samples collected at Allen Street also exceeded the TEL 

and 5 also exceeded the PEC. At Hudson, most of the samples 

had Zn concentrations lower than the TEL; none exceeded 

the PEC, but samples from H13 and H15 had Zn concentrations higher than the PEL. At Gleasondale, concentrations 

in samples from only sites G18, G19, and G22 exceeded the 

sediment-quality guidelines. In the Ben Smith impoundment, 

most of the samples whose concentrations exceeded the Zn 

guidelines were taken from the upstream area, the Zn PEC was 

exceeded by concentrations in at least one sample from BS30 

to BS32, BS34, and BS38. At Powdermill, Zn concentrations 

in more than half (21) of the samples exceeded the TEL; 8 

of those samples also had Zn concentrations greater than the 

PEC; 4 were in excess of 1,000 mg/kg.

Reactive Sulfide

Only one sample had a reactive sulfide concentration 

(1,570 mg/kg) that exceeded the minimum reporting level of 

5 mg/kg. The sample came from a completely homogenized, 

62-cm core from the Gleasondale impoundment, site G22 

(fig. 12). Sediment from this site also exhibited higher concentrations of toxic metals than sediment from the other sites at 

Gleasondale (table 3). 

Organic Analyses

Because only a subset of the cores selected for organicchemistry analyses were sectioned, it is not possible to make 

broad generalizations about concentration trends with depth. 

Changes with depth are discussed for individual cores and 

more general interpretations are based on means or medians of 

all samples collected within an impoundment.

28 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Volatile Organic Compounds and Organochlorine 

Pesticides

Matrix interference in all VOC and organochlorinepesticide samples required sample dilution by factors as great 

as 100. Such dilutions caused reporting levels to increase by 

the same factors. As a probable result of these effects, the analytical laboratories reported no detections for either category 

of compound. The lack of detections, however, should not be 

interpreted to mean that the compounds were absent in the 

tested samples because the compounds were detected in New 

England by Harris (1997) and Chalmers (2002). A regional 

study of organochlorine pesticides in New England conducted 

from 1992 to 1994 by Harris (1997) reported the detection 

of dichlorodiphenyltrichloroethane, chlordane, and some of 

their metabolites, as well as nonachlor and dieldrin. A more 

recent study (Chalmers, 2002) reported detections of the same 

compounds in sediments in a different set of New England 

streams. 

Polycyclic Aromatic Hydrocarbons

PAHs are one of the most frequently detected types of 

compounds in sediments. As particles from incomplete hydrocarbon combustion and in runoff from roads and parking lots, 

PAHs eventually enter water bodies, adsorb to other particles, 

and sink to the bottom. These compounds exhibit carcinogenic 

and mutagenic properties (Somers and others, 2004), and 

hence may affect human health and aquatic life.

Among the six impoundments, the highest mean 

and median total PAH concentrations, 89,500 μg/kg and 

16,500 μg/kg, respectively, were found in sediment samples 

from the Powdermill impoundment. Samples from Ben Smith 

had the lowest median total PAH concentration (615 μg/kg), 

and Aluminum City had the lowest mean total PAH concentration (2,850 μg/kg); Ben Smith also had a relatively low mean 

total PAH concentration (4,520 μg/kg). In samples from Allen 

Street, Hudson, and Gleasondale, the mean PAH concentrations were similar, whereas the medians differed considerably 

in samples from these three impoundments (table 6).

No general total PAH vertical-distribution patterns appear 

obvious among the sectioned samples (table 16, at back of 

report). Many seem to decrease with increasing depth (for 

example, AC4, H13, G18, BS30, BS32, BS38, BS43, P54), 

while others increase (BS31, P48), and some exhibit no 

clear trend with depth (AS7, G19, P56). These data demonstrate, at minimum, the variability in the distribution of PAH 

compounds deposited over time.

Concentrations of total PAHs in many (9 of 20) of the 

samples from the Powdermill impoundment exceed the PEC 

sediment-quality guideline of 22,800 μg/kg (Ingersoll and 

others, 2000; table 16). Few samples from the other impoundments exceed this value: Aluminum City (0), Allen Street (1), 

Hudson (3), Gleasondale (4), and Ben Smith (2) (fig. 15). 

A sample from the Powdermill impoundment had the 

highest total PAH concentration (site P50, 1,100,000 μg/kg); 

this impoundment had a sample from one additional site 

(P52) with a total PAH concentration that exceeded the 

Massachusetts standard of 100,000 μg/kg for sediment reuse 

at lined landfills. Other impoundment sites exhibiting high 

total PAH concentrations include AS5 and AS7 (Allen Street), 

H10 and H13 (Hudson), G18 and G19 (Gleasondale), BS30 

and BS31 (Ben Smith), and P46, P47, P48, P53, and P56 

(Powdermill).

Many samples had concentrations of individual PAH 

compounds that exceeded PEL and PEC sediment-quality 

guidelines (tables 3 and 16). The Powdermill impoundment 

yielded the largest percentage of samples that exceeded 

the guidelines; Aluminum City and Ben Smith yielded the 

smallest percentage of samples. 

Polychlorinated Biphenyls

Total PCB concentrations and individual Aroclor concentrations differed substantially within and among the impoundments (table 7; fig. 16). No PCBs were detected in any of the 

Hudson-impoundment samples. Only Aroclors 1248, 1254, 

and 1260 were detected in samples from Aluminum City, 

Allen Street, and Ben Smith impoundments; only Aroclors 

1254, 1260, and 1262 were detected in Ben Smith; and only 

Aroclors 1254, 1260, and 1268 were found in samples from 

Powdermill. 

Only one sample, from Gleasondale impoundment 

site G18, had a total PCB concentration (3,100 μg/kg) that 

exceeded the maximum allowable for sediment reuse in lined 

landfills and for human contact (2,000 μg/kg); however, all 

samples except for two (AC4 and BS28) with detectable PCB 

concentrations exceeded the TEL sediment-quality guideline 

of 34.1 μg/kg; about half of the sites (14 of 30) also had total 

PCB concentrations greater than the PEL of 277 μg/kg; eight 

of the sites (G18, G19, BS30, BS33, BS34, BS43, P48, and 

P56) also had total PCB concentrations that were higher than 

the PEC of 676 μg/kg. In addition, most of the samples in 

which Aroclors 1248, 1254, and 1262 were detected exceeded 

the PEC values for these individual PCB Aroclors (table 2).

Table 6. Median and mean values for total polycyclic aromatic 

hydrocarbon concentrations detected in sediment samples from 

six impoundments in the Assabet River Basin, Massachusetts, 

2003.

[All values are in micrograms per kilogram]

Impoundment Median Mean

Aluminum City 2,950 2,850

Allen Street 12,100 19,000

Hudson 1,140 18,900

Gleasondale 3,000 16,700

Ben Smith 615 4,520

Powdermill 16,500 89,500

Sediment Chemistry of the Assabet River Impoundments 29
Figure 15. Total polycyclic aromatic hydrocarbon concentrations in core samples from six impoundments in the Assabet River, 

central Massachusetts, 2003.

Figure 16. Concentrations of selected polychlorinated biphenyl Aroclors detected in core samples from six impoundments in the Assabet River, central Massachusetts, 2003. AC1 AC2 AC3 AC4 AS5 AS6 AS7 AS8 H9 H10 H11 H12 H13 H14 H15 G16 G17 G18 G19 G20 G21 G22 G23 G24 G25 G26 G27 BS28 BS29 BS30 BS31 BS32 BS33 BS34 BS35 BS36 BS37 BS38 BS39 BS40 BS41 BS42 BS43 BS44 BS45 P46 P47 P48 P49 P50 P51 P52 P53 P54 P55 P56

P57

SAMPLING SITE

0

50,000

100,000

150,000

200,000

1,050,000

1,100,000

1,150,000

CONCENTRATIONS OF TOTAL POLYCYCLIC AROMATIC 

HYDROCARBON, IN MICROGRAMS PER KILOGRAM

AC1AC2AC3AC4

AS5AS6AS7AS8

H9

H10H11H12H13H14H15

G16G17G18G19G20G21G22G23G24G25G26G27

BS28BS29BS30BS31BS32BS33BS34BS35BS36BS37BS38BS39BS40BS41BS42BS43BS44BS45

P46P47P48P49P50P51P52P53P54P55P56P57

SAMPLING SITE

0

200

400

600

800

1,000

1,200

CONCENTRATIONS OF POLYCHLORINATED BIPHENYL

ALOCLORS, IN MICROGRAMS PER KILOGRAM

AROCLORS

1248

1254

1260

1262

1268

30 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Table 7. Concentrations of polychlorinated biphenyl Aroclors in sediment samples from six impoundments in the Assabet River Basin, 

Massachusetts, 2003.—Continued

[All values are in micrograms per kilogram. Minimum reporting level is 0.17 micrograms per kilogram. Map ID: The identifier associated with a sampling site 

on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating 

a replicate sample. Total PCB: Sum of detectable concentrations of Aroclors rounded to three significant figures. Shaded numbers exceed sediment-quality 

guidelines. PCB, polychlorinated biphenyl, --, not detected]

Map ID Sample ID

Aroclor

Total PCB

1248 1254 1260 1262 1268

Aluminum City

AC1 5 85.2 91 72.6 -- -- 249

AC2 7 121 163 159 -- -- 443

AC3 6 190 184 142 -- -- 516

AC4 8A -- 126 102 -- -- 228

AC4 8B 126 100 69.2 -- -- 295.2

AC4 8C -- 24.7 25.2 -- -- 49.9

Allen Street

AS5 1 -- -- -- -- -- --

AS6 3 91.2 71.7 51.6 -- -- 214

AS7 2A 61.3 129 142 -- -- 332

AS7 2B -- -- -- -- -- --

AS7 2C -- -- -- -- -- --

AS8 4 -- 63.5 -- -- -- 63.5

Hudson

H9 9 -- -- -- -- -- --

H10 12 -- -- -- -- -- --

H10 12Q -- -- -- -- -- --

H11 13 -- -- -- -- -- --

H12 11A -- -- -- -- -- --

H12 11B -- -- -- -- -- --

H13 14A -- -- -- -- -- --

H13 14AQ -- -- -- -- -- --

H13 14B -- -- -- -- -- --

H13 14BQ -- -- -- -- -- --

H13 14C -- -- -- -- -- --

H13 14CQ -- -- -- -- -- --

H14 10 -- -- -- -- -- --

H15 15 -- -- -- -- -- --

Gleasondale

G16 34 -- -- -- -- -- --

G17 39 -- -- -- -- -- --

G18 35A -- 3,100 -- -- -- 3,100

G18 35B -- -- -- -- -- --

G18 35C -- -- -- -- -- --

G19 40A -- 1,960 -- -- -- 1,960

G19 40B -- 1,050 234 -- -- 1,280

G19 40C -- -- -- -- -- --

G19 40CQ -- -- -- -- -- --

G20 36 -- -- -- -- -- --

Sediment Chemistry of the Assabet River Impoundments 31
Table 7. Concentrations of polychlorinated biphenyl Aroclors in sediment samples from six impoundments in the Assabet River Basin, 

Massachusetts, 2003.—Continued

[All values are in micrograms per kilogram. Minimum reporting level is 0.17 micrograms per kilogram. Map ID: The identifier associated with a sampling site 

on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating 

a replicate sample. Total PCB: Sum of detectable concentrations of Aroclors rounded to three significant figures. Shaded numbers exceed sediment-quality 

guidelines. PCB, polychlorinated biphenyl, --, not detected]

Map ID Sample ID

Aroclor

Total PCB

1248 1254 1260 1262 1268

Gleasondale—Continued

G20 36Q -- -- -- -- -- --

G21 44 -- 67.2 -- -- -- 67.2

G22 41 -- 223 110 -- -- 333

G23 37 -- -- -- -- -- --

G24 42 -- 493 -- 133 -- 626

G25 45 -- 219 35.5 -- -- 254

G26 38 -- -- -- -- -- --

G27 43 -- 117 -- 42.6 -- 160

Ben Smith

BS28 16 -- 122 26.7 -- -- 149

BS29 18 -- -- -- -- -- --

BS30 17A -- 1,300 247 -- -- 1,550

BS30 17B -- -- -- -- -- --

BS30 17C -- -- -- -- -- --

BS31 19A -- -- -- -- -- --

BS31 19AQ -- -- -- -- -- --

BS31 19B -- -- -- -- -- --

BS31 19BQ -- -- -- -- -- --

BS31 19C -- 332 -- -- -- 332

BS31 19CQ -- -- -- -- -- 352

BS32 20A -- 335 130 -- -- 465

BS32 20B -- -- -- -- -- --

BS32 20C -- -- -- -- -- --

BS33 21 234 417 142 -- -- 793

BS34 22 250 319 180 -- -- 749

BS35 23 -- 258 -- -- -- 258

BS36 27 -- -- -- -- -- --

BS37 29 -- -- -- -- -- --

BS38 26A -- -- -- -- -- --

BS38 26B -- -- -- -- -- --

BS38 26C -- -- -- -- -- --

BS39 25 -- -- -- -- -- --

BS40 24 -- 77 -- -- -- 77

BS41 28 -- -- -- -- -- --

BS42 33 -- 136 -- -- -- 136

BS43 30A -- 1,300 309 -- -- 1,610

BS43 30B -- 212 -- -- -- 212

BS43 30C -- -- -- -- -- --

BS44 31 -- -- -- -- -- --

BS45 32 -- 57.8 -- -- -- 57.8

32 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Table 7. Concentrations of polychlorinated biphenyl Aroclors in sediment samples from six impoundments in the Assabet River Basin, 

Massachusetts, 2003.—Continued

[All values are in micrograms per kilogram. Minimum reporting level is 0.17 micrograms per kilogram. Map ID: The identifier associated with a sampling site 

on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating 

a replicate sample. Total PCB: Sum of detectable concentrations of Aroclors rounded to three significant figures. Shaded numbers exceed sediment-quality 

guidelines. PCB, polychlorinated biphenyl, --, not detected]

Map ID Sample ID

Aroclor

Total PCB

1248 1254 1260 1262 1268

Powdermill

P46 48 -- 91.7 -- -- 116 208

P46 48Q -- 108 -- -- 69.3 177

P47 49 -- 141 -- -- 112 253

P48 46A -- -- -- -- -- --

P48 46B -- -- -- -- -- --

P48 46C -- 422 -- -- 424 846

P49 47 -- -- -- -- -- --

P50 52 -- -- -- -- -- --

P51 55 -- -- -- -- -- --

P52 53 -- -- -- -- -- --

P53 56 -- -- -- -- -- --

P54 54A -- -- -- -- -- --

P54 54B -- -- -- -- -- --

P54 54C -- -- -- -- -- --

P55 51A -- -- -- -- -- --

P55 51B -- -- -- -- -- --

P55 51C -- -- -- -- -- --

P56 50A -- 631 -- -- 177 808

P56 50AQ -- 726 381 -- 178 1,280

P56 50B -- 273 -- -- 113 386

P56 50C -- -- -- -- -- --

P57 57 -- -- -- -- -- --

Sediment Chemistry of the Assabet River Impoundments 33
Extractable Petroleum Hydrocarbons

EPH analysis, the measure of the sum of the concentrations of extractable aliphatic (C9

 to C18 and C19 to C36) and 

aromatic (C11 to C22) petroleum hydrocarbons, provides data 

used to evaluate the effect of exposure of these compounds 

on human health. The sum of the concentrations of these 

compounds for a particular sample, plus the sum of the 17 

PAHs also determined by this method, yields the traditional 

total petroleum hydrocarbon (TPH) value (Massachusetts 

Department of Environmental Protection, 2004). 

The sources of petroleum hydrocarbons are atmospheric, 

and include incomplete combustion as well as direct releases 

of petroleum hydrocarbons. The EPH-method analyses are 

reported at levels greater than those required for cleanup in 

drinking-water-resources areas. Because this report previously 

considered the results of more sensitive analyses for individual 

PAHs, and because the Massachusetts EPH toxicological 

approach focuses on human health concerns, this section does 

not refer to specific PAHs determined by the EPH method.

The Powdermill impoundment had the highest median 

and mean total EPH concentrations along with the highest 

concentrations measured in individual samples in this study 

(table 8). The highest measured total EPH concentration 

(438 mg/kg from the surface sample at site P54) was at least 

an order of magnitude less than the maximum allowable concentration for landfill reuse of approximately 5,000 mg/kg (the 

TPH maximum of 5,000 mg/kg implicitly includes the PAH 

maximum of 100 mg/kg). 

Few samples had individual PAH concentrations that 

were high enough to be detected by the EPH method (concentration data not included in this report). In the Powdermill 

impoundment, samples with concentrations high enough to 

allow detection of individual PAHs by means of the EPH 

method were taken from sites P46 to P54; the three remaining downstream sites (P55 to P57) were close to the dam and 

a diversion outlet through which hydraulic conditions may 

have carried particles with high PAH concentrations out of the 

impoundment. Two sites at Hudson (H10 and H13) and one at 

Ben Smith (BS30) also had a few PAHs that were detectable 

by the EPH method.

Potential for Adverse Biological Effects

Sediment-quality guidelines (Ingersoll and others, 2001; 

McDonald and others, 2000) were used to evaluate the potential for bottom sediments from the six impoundments to have 

toxic effects on aquatic biota. The chemical compositions of 

the Assabet River impoundment sediment samples were compared with the chemistry of sediments known to have toxic 

effects from a database of 1,657 previous North American 

sediment-toxicity studies; the guidelines were derived from 

this database (Ingersoll and others, 2001). Because none of 

the samples in this database were from New England, regional 

variability was not considered in interpreting results. The 

likelihood that any one sample will have a toxic effect, the 

“incidence of toxicity,” refers to the percentage of sediment 

samples having any negative effect on the growth or survivability of test organisms.

The sediment-quality database incorporates measures 

by test assays of the growth and survivability of two benthic 

organisms: the amphipod, Hyalella azteca (HA10 and HA28, 

10 and 28-day tests, respectively) and an aquatic insect larva, 

Chironomous spp. (CS10 day test). The longer HA28 test is 

generally more sensitive and provides a higher incidence of 

toxicity values than the short-term test (Ingersoll and others, 

2001). 

The USEPA determined PECs for 28 freshwater-sediment 

contaminants of concern in the major chemical groups of trace 

metals, PAHs, PCBs, and pesticides (MacDonald and others, 

2000; Ingersoll and others, 2001); these contaminants are 

considered to be reliable predictors of sediment toxicity. PEC 

values are used to estimate sediment toxicity where adverse 

conditions for biota are expected. In the development of the 

sediment-quality guidelines, toxicity predictions were considered reliable if the toxicity was correctly predicted for more 

than 75% of the sediment samples. 

Data from sediment samples were processed as described 

by MacDonald and others (2000) and Ingersoll and others 

(2001). Censored data from a particular site were given 

values equal to one half of the RL. If all data from a site were 

censored, then concentrations equal to the RL were assigned. 

After these data filters were applied, individual concentrations 

of trace elements, PAHs, and PCBs at a particular site were 

added within their respective groups to yield total values. If 

the total of nondetected values (that is, the sum of the assigned 

RLs) at a site was greater than that chemical group’s PEC 

value, then that total was excluded from the calculations. Total 

values not excluded were divided by their respective PEC 

values to obtain a PEC quotient. 

The PEC quotients of the chemical groups for each site 

were then summed and averaged and referred to as mean MPP 

values for that site (MPP refers to Metals, PAHs, and PCBs). 

In this study, mean MPPs were determined by two methods: 

(1) an equal-weight mean of the three chemical groups, 

referred to as MPP(and), and (2) MPP(or), a mean calculated 

only for metals and PAHs (shown in boldface type in table 9). 

Because of analytical interferences reported by the laboratory, pesticide values were all less than RLs and were omitted 

entirely from the toxicity estimations. The mean MPP values 

were compared to five PEC-quotient ranges developed by 

Ingersoll and others (2001) to establish a relation between the 

ranges and the incidences of sediment toxicity determined by 

the organism tests; the PEC-quotient ranges are: <0.1, 0.1 to 

<0.5, 0.5 to <1.0, 1.0 to <5.0, and >5.0. For example, a mean 

MPP range of 0.5 to 1.0 is associated with a 50-percent incidence of toxicity in the HA28 test (Zimmerman and Breault, 

2003).

34 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Table 8. Concentrations of extractable petroleum hydrocarbons in sediment samples from six impoundments in the the Assabet River 

Basin, Massachusetts, 2003.—Continued

[All concentrations are shown in milligrams per kilogram. Minimum reporting level is 10 milligrams per kilogram. Total EPH and means and medians for 

each impoundment were calculated using 10 as an estimate for all <10 values where other values were 10 or greater. Map ID: The identifier associated with a 

sampling site on a map (figs. 9–14). Sample ID: Identifier of a sample collected from a particular core, arranged alphabetically from the top of the core. EPH, 

extractable petroleum hydrocarbon; <, actual value is less than value shown]

Map ID Sample ID C9-C18 aliphatic 

hydrocarbons

C19-C36 aliphatic 

hydrocarbons

C11-C22 aromatic 

hydrocarbons Total EPH

Aluminum City

AC1 5 <10 10 20 40

AC2 7 <10 15 32 57

AC3 6 <10 14 29 53

AC4 8A <10 <10 26 46

AC4 8B <10 21 30 61

AC4 8C <10 <10 12 32

Mean <10 13 25 38

Median <10 12.0 27.5 39.5

Allen Street

AS5 1 <10 85 53 148

AS6 3 <10 14 18 42

AS7 2A <10 38 24 72

AS7 2B <10 22 22 54

AS7 2C <10 49 47 106

AS8 4 <10 29 38 77

Mean <10 40 34 73

Median <10 33.5 31.0 64.5

Hudson

H9 9 <10 <10 20 40

H10 12 <10 <10 27 47

H11 13 <10 <10 14 34

H12 11A <10 <10 14 34

H12 11B <10 <10 13 33

H13 14A <10 <10 26 46

H13 14B <10 <10 16 36

H13 14C <10 <10 <10 30

H14 10 <10 <10 14 34

H15 15 <10 <10 <10 30

Mean <10 <10 17 27

Median <10 <10 15.0 35.0

Gleasondale

G16 34 <10 <10 13 33

G17 39 <10 <10 <10 30

G18 35A 71 115 78 264

G18 35B <10 37 28 75

G18 35C <10 25 21 56

G19 40A 12 38 43 93

G19 40B 33 76 90 199

G19 40C <10 <10 17 37

G20 36 <10 11 32 52

G21 44 <10 11 15 36

Sediment Chemistry of the Assabet River Impoundments 35
Table 8. Concentrations of extractable petroleum hydrocarbons in sediment samples from six impoundments in the the Assabet River 

Basin, Massachusetts, 2003.—Continued

[All concentrations are shown in milligrams per kilogram. Minimum reporting level is 10 milligrams per kilogram. Total EPH and means and medians for 

each impoundment were calculated using 10 as an estimate for all <10 values where other values were 10 or greater. Map ID: The identifier associated with a 

sampling site on a map (figs. 9–14). Sample ID: Identifier of a sample collected from a particular core, arranged alphabetically from the top of the core. EPH, 

extractable petroleum hydrocarbon; <, actual value is less than value shown]

Map ID Sample ID C9-C18 aliphatic 

hydrocarbons

C19-C36 aliphatic 

hydrocarbons

C11-C22 aromatic 

hydrocarbons Total EPH

Gleasondale—Continued

G22 41 <10 31 30 71

G23 37 <10 22 23 55

G24 42 <10 15 12 37

G25 45 <10 <10 <10 30

G26 38 <10 <10 62 82

G27 43 <10 <10 10 30

Mean 15 26 30 71

Median <10 12.5 22.0 34.5

Ben Smith

BS28 16 <10 <10 <10 30

BS29 18 <10 11 26 47

BS30 17A <10 47 39 96

BS30 17B <10 13 39 62

BS30 17C <10 14 30 54

BS31 19A <10 70 38 118

BS31 19B <10 54 <10 74

BS31 19C <10 43 <10 63

BS32 20A 11 75 80 166

BS32 20B <10 31 54 95

BS32 20C <10 31 58 99

BS33 21 <10 21 49 80

BS34 22 <10 <10 59 79

BS35 23 <10 40 48 98

BS36 27 <10 <10 <10 30

BS37 29 <10 <10 12 32

BS38 26A <10 15 36 61

BS38 26B <10 <10 21 41

BS38 26C <10 <10 11 31

BS39 25 <10 <10 38 58

BS40 24 <10 <10 31 51

BS41 28 <10 <10 <10 30

BS42 33 <10 <10 21 41

BS43 30A <10 13 34 57

BS43 30B <10 <10 24 44

BS43 30C <10 <10 <10 30

BS44 31 <10 <10 11 31

BS45 32 <10 <10 13 33

Mean <10 64 45 120

Median <10 46.5 31.0 77.5

36 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Table 8. Concentrations of extractable petroleum hydrocarbons in sediment samples from six impoundments in the the Assabet River 

Basin, Massachusetts, 2003.—Continued

[All concentrations are shown in milligrams per kilogram. Minimum reporting level is 10 milligrams per kilogram. Total EPH and means and medians for 

each impoundment were calculated using 10 as an estimate for all <10 values where other values were 10 or greater. Map ID: The identifier associated with a 

sampling site on a map (figs. 9–14). Sample ID: Identifier of a sample collected from a particular core, arranged alphabetically from the top of the core. EPH, 

extractable petroleum hydrocarbon; <, actual value is less than value shown]

Map ID Sample ID C9-C18 aliphatic 

hydrocarbons

C19-C36 aliphatic 

hydrocarbons

C11-C22 aromatic 

hydrocarbons Total EPH

Powdermill

P46 48 <10 83 61 154

P47 49 <10 12 41 63

P48 46A <10 <10 <10 30

P48 46B <10 <10 12 32

P48 46C <10 101 75 186

P49 47 <10 14 31 55

P50 52 14 54 92 160

P51 55 14 178 31 223

P52 53 <10 24 55 89

P53 56 22 41 118 181

P54 54A <10 253 175 438

P54 54B 26 171 29 226

P54 54C 10 52 12 74

P55 51A <10 <10 <10 30

P55 51B <10 <10 <10 30

P55 51C <10 <10 <10 30

P56 50A 12 75 45 132

P56 50B 13 142 77 232

P56 50C 10 10 <10 30

P57 57 <10 <10 <10 30

Mean 11.9 64.3 44.9 121

Median <10 46.5 31.0 77.5

Sediment Chemistry of the Assabet River Impoundments 37
Map ID Mean MPP HA10 HA28 CS10

Aluminum City

AC1 0.22 26 6 35

AC2 .36 26 6 35

AC3 .37 26 6 35

AC4 .51 38 50 35

Allen Street

AS5 0.82 38 50 35

AS6 .24 26 6 35

AS7 .84 38 50 35

AS8 .24 26 6 35

Hudson

H9 0.22 26 6 35

H10 1.12 49 100 50

H11 .18 26 6 35

H12 .12 26 6 35

H13A 1.09 41 97 43

H13B .57 38 50 35

H13C .25 26 6 35

H14 .12 26 6 35

H15 .34 26 6 35

Gleasondale

G16 0.30 26 6 35

G17 .13 26 6 35

G18 5.31 86 100 78

G19 3.49 49 100 50

G20 .29 26 6 35

G21 .11 26 6 35

G22 .48 26 6 35

G23 .04 18 10 20

G24 .42 26 6 35

G25 .19 26 6 35

G26 .05 18 10 20

G27 .18 26 6 35

Ben Smith

BS28 0.12 26 6 35

BS29 .33 26 6 35

BS30 1.28 49 100 50

BS31 .05 18 10 20

Map ID Mean MPP HA10 HA28 CS10

Ben Smith—Continued

BS32 1.47 49 100 50

BS33 .56 38 50 35

BS34 .56 38 50 35

BS35 .35 26 6 35

BS36 .14 26 6 35

BS37 .16 26 6 35

BS38 .18 16 13 17

BS39 .01 18 10 20

BS40 .18 26 6 35

BS41 .13 26 6 35

BS42 .19 26 6 35

BS43 1.61 49 100 50

BS44 .13 26 6 35

BS45 .08 19 4 29

Powdermill

P46A 0.11 26 6 35

P46B .16 26 6 35

P46C 1.17 49 100 50

P47 .72 38 50 35

P48 .18 26 6 35

P49 .00 18 10 20

P50 2.41 49 100 50

P51 .24 26 6 35

P52 3.29 41 97 43

P53 .29 26 6 35

P54A 1.13 49 100 50

P54B .07 19 4 29

P54C .03 18 10 20

P55 19.36 71 97 68

P56 .60 38 50 35

P57 1.75 41 97 43

Table 9. Incidence of toxicity, in percent, and mean MPP values calculated from Probable Effect Concentration quotients for sediment 

samples from the six impoundments in the Assabet River Basin, Massachusetts, 2003. 

[Map ID: The identifier associated with a sampling site on a map (figs. 9–14). Data for HA10, HA28, and CS10 toxicity tests from the U.S. Environmental 

Protection Agency (2000) and Ingersoll and others (2001). Boldface type indicates Mean MPP (or) method was used because of censored data. All other Mean 

MPP data were calculated by the Mean MPP (and) method. Sites H13, P46, and P54 were sampled at three depths in the cores indicated by the letter A, B, C 

appended to the Map ID]

38 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Sediment-sample mean MPP values indicated an increasing trend downstream. For simplicity’s sake, the incidences of 

toxicity that were used for comparison were from the HA28 test, a more sensitive test than the HA10 and CS10 tests. 

From the Aluminum City impoundment, the highest mean 

MPP from site AC4 (0.51) was associated with an incidence 

of toxicity of 50 percent. Allen Street sediment samples from 

sites AS5 and AS7 both had mean MPP values greater than 

0.80 and incidences of toxicity of 50 percent. Two Hudson 

impoundment sites, H10 and H13, gave samples with high 

mean MPPs and incidences of toxicity of 100 and 97 percent, respectively. Samples from sites G18 and G19 in the 

Gleasondale impoundment gave some of the largest mean 

MPPs of the study: 5.31 and 3.49, respectively, with 100 percent incidences of toxicity. The Ben Smith impoundment had 

five sites that gave samples with mean MPPs greater than 0.5 

and incidences of toxicity of 50 or 100 percent: BS30 (1.28), 

BS32 (1.47), BS33 (0.56), BS34 (0.56), and BS43 (1.61). A 

sample from a site in the Powdermill impoundment had the 

highest mean MPP of the study: P55 (19.36). The Powdermill 

impoundment also had seven other sites that gave samples 

with high mean MPPs and incidences of toxicity greater than 

50 percent: sites P46 (1.17, in the deepest sediment sample), 

P47 (0.72), P56 (0.60), P50 (2.41), P52 (3.29), P54 (1.13, in 

the surface sample), and P57 (1.75). 

As a result of the sediment-processing procedures, all 

incidence-of-toxicity results (figs. 9 to 14) represent the entire 

core sample except for the results for stations H13, P46, and 

P54, which include the toxicity at three individual depths 

within the cores. The incidences of toxicity for the surface 

sediments at these three sites appear to be higher than for 

some of the completely homogenized samples (with the exception of site P46, which was effectively a surface-sediment core 

sample because its total length was less than 30 cm). Likewise, 

the deepest sediments appear to have lower toxicities than 

some of the completely homogenized samples. An entire core 

with retrieval depths more than 60 cm may include preimpoundment sediments that have not been affected by human 

activities; thus, analytical results of tests on such a core may 

show a bias toward a lower toxicity. If this hypothesis is valid, 

the incidences of toxicity presented in this report (with the 

exception of sites H13, P46, and P54) may be underestimated. 

Sediment Distribution and Chemistry—

Possible Implications for Sediment 

Management

The six Assabet River impoundments differed greatly 

in size and sediment volume, with Aluminum City having a 

sediment volume of only 380 m3 and Ben Smith 580,000 m3

(table 10). Results of chemical analyses of sediment differed 

considerably within and among the impoundments. In general, 

guideline exceedances increased in the downstream direction. 

The chemical analyses revealed that toxic metal and PAH concentrations exceeded quantitative sediment-quality guidelines 

in almost all samples. PCBs were not detected in as many 

samples as metals and PAHs were, but all PCB detections 

exceeded at least one guideline. Chemical-matrix interference 

was cited by two laboratories to explain why they did not 

detect VOCs and organochlorine pesticides in any samples; 

failure to detect these compounds, however, does not imply 

their absence.

Regional variability was not taken into consideration in 

interpreting incidence of toxicity data; nevertheless, there is no 

reason to expect that the incidence of toxicity data calculated 

from contaminant concentrations in New England sediments 

would be different from data calculated from contaminant 

concentrations in any other region. Approximately one third 

of the sediment samples could be expected to exhibit toxic 

effects (lethality, growth inhibition, or reproductive diminution) on test organisms with a likelihood of 50 percent or 

more. Although USEPA guidelines that focus on the health of 

aquatic organisms were commonly exceeded in the impoundments, the MDEP guidelines for landfill disposal of dredged 

materials were exceeded in only a small percentage of samples. If sediment dredging were undertaken, it may be possible 

to dilute sediments that exceed MDEP disposal standards with 

less contaminated sediments to produce an acceptable mixture. 

Selective dam removal or modification (partial removal or 

lowering of dam crests) might improve aesthetics and, to some 

extent, restore natural conditions, but could still leave toxic 

sediments intact or allow them to be transported downstream 

to the next impoundment. 

If adequate disposal areas can be found, these results 

could be interpreted to suggest that extensive dredging might 

improve the aquatic habitat of the Assabet River. Dredging 

could also remove much of the sediment phosphorus, which is 

most highly concentrated in surficial sediments, but whether 

this removal would reverse the eutrophic conditions in the 

impoundments is unknown because the relation between bulksediment phosphorus concentrations and phosphorus availability as an algal nutrient is not well understood. Dredging 

could create deeper pools with increased thermal stratification 

and additional potential for sediment-phosphorus release. In 

addition, the high nutrient concentrations in wastewater effluent from treatment plants may still be sufficient to support 

nuisance growths of rooted and floating macrophytes and 

epiphytic algae in the impounded and free-flowing reaches of 

the river, in which case the dredging would only provide shortterm benefits. 

Sediment Distribution and Chemistry—Possible Implications for Sediment Management 39
Table 10. Selected characteristics of six impoundments in the Assabet River Basin, Massachusetts. Exceedances listed reflect one or 

more samples in an impoundment. 

[PEC, probable effect concentration; PEL, probable effect level; m3, cubic meter; m, meter; m2, square meter]

Impoundment

Maximum

water depth

(m)

Maximum 

sediment 

thickness

(m)

Sediment 

volume

(m3)

Approximate

impoundment

length

(m)

Impoundment area

(m2)

Chemical groups that 

exceeded aquaticlife guidelines

(PEL or PEC)

Chemical groups 

that exceeded 

landfill-reuse 

guidelines

Aluminum City 1.2 1.0 380 110 1,600 Cr, Cu, Pb, PCB, PAH Cr

Allen Street 2.5 3.6 42,000 890 28,000 Cd, Cr, Cu, Pb, Zn, 

PCB, PAH

Hudson 3.0 2.3 55,000 5,300 89,000 As, Cd, Cr, Cu, Pb, Ni, 

Zn, PAH

As

Gleasondale 3.3 5.6 67,000 990 55,000 As, Cd, Cr, Cu, Pb, Ni, 

Zn, PCB, PAH

As, PCB

Ben Smith 3.3 7.5 580,000 11,000 590,000 As, Cd, Cr, Cu, Pb, Ni, 

Zn, PCB, PAH

As, Pb

Powdermill 2.5 2.7 120,000 4,800 110,000 As, Cd, Cr, Cu, Pb, Ni, 

Zn, PCB, PAH

As, Cr, Pb, PAH

40 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Introduction

Nutrient total maximum daily loads (TMDLs) are being 

developed for streams in Massachusetts, many of which 

have water-quality-impairment issues similar to those of 

the Assabet River. Recent TMDL assessment and modeling 

studies of the Assabet River have documented the extent of 

eutrophication of the river’s impoundments and free-flowing 

reaches, and suggested that phosphorus releases from bed 

sediments may continue to promote excessive plant growth 

in the river even if loads from wastewater-treatment plants 

and other point sources were eliminated (ENSR International, 

2001, 2004). Data from environmental-assessment and laboratory studies of phosphorus release from sediments were used 

by ENSR International to develop and test the model that 

developed several management scenarios to provide acceptable alternatives for improving water quality enough to meet 

standards. All alternatives included reductions in phosphorus 

loadings from treatment plants and from sediments. According 

to the ENSR International study recommendations, attainment of water-quality standards may entail a combination of 

removal of the bed sedi­ments, chemical treatment to immobilize sediment phosphorus, or dam removal or breaching 

to increase flows and disperse some of the sediments. More 

detailed informa­tion on the distribution, transport, and internal 

cycling of phosphorus between sediments and surface water 

as well as on external phosphorus loading would help managers select the most cost-effective course of action. A judgment could then be made whether annual fluxes of sediment 

phosphorus in the river are of sufficient magnitude to require 

dredging, or if dam removal or breaching can be used to 

achieve water-quality and other environmental goals.

The relation between bulk-sediment phosphorus concentrations, discussed elsewhere in this report, and the release of 

phosphorus from sediments remains uncertain. Sediment pore 

water may contain phosphorus in high enough concentrations 

to become available to aquatic plants as a nutrient in the water 

column if conditions permit. Mortimer (1971), Boström and 

others (1982), and Nürnberg (1988) describe many factors 

that combine to control the release of sediment phosphorus to 

the water column. Foremost among these are the oxidationreduction (redox) conditions at the sediment-water interface 

that control the availability of loosely bound, or adsorbed, 

phosphorus, and phosphorus that is bound to iron hydroxides. 

As reducing conditions intensify, phosphorus unbinds and may 

move into the water column in the form of a dissolved phosphate ion that is available for absorption by aquatic plants. 

Anoxic conditions are most likely to develop in the deep parts 

of impoundments during summer and early autumn low-flow 

periods and perhaps in areas where floating macrophytes (for 

example, Lemna sp.) completely cover the surface; the combination of biochemical oxygen demand in the water column and 

macrophytes blocking light needed to support oxygen-yielding 

photosynthesis by algae could create this situation. However, 

the presence of nitrate is known to suppress the release of 

phosphorus by maintaining a high redox potential (Golterman, 

2004; Tiren and Petterson, 1985; Andersen, 1982); high ambient nitrate concentrations sustained by releases from treatment 

plants along the Assabet River might produce this effect.

Recent laboratory studies by ENSR International (2001) 

to determine the potential for Assabet River sediments to 

release phosphorus sufficient to constitute a substantial fraction of the measured water-column phosphorus mass yielded 

mixed results. The water column actually lost phosphorus 

to sediment cores collected in March 2000 and incubated 

at ambient temperatures. Phosphorus release was observed 

from cores that were incubated at temperatures elevated 

above ambient; however, phosphorus released from the sediments amounted to less than 3 percent of the water-column 

phosphorus. When the water overlying cores collected in 

September 2000 was allowed to become anaerobic, however, 

the study reported that the sediments released as much as 170 

percent of the pre-existing water-column phosphorus concentrations into the water column. On the other hand, the report 

noted that the waters in the impoundments rarely became 

anaerobic. Sediments never previously exposed to anaerobic conditions may have substantial amounts of iron-bound 

phosphorus that would not have been released under normal 

(aerobic) conditions.

To resolve uncertainty inherent in extrapolating laboratory results to field conditions, a field study examining 

changes in concentrations of total phosphorus and orthophosphorus took place from July to September 2003. The purpose 

of the field study was to determine whether phosphorus was 

likely to be released from the sediments in concentrations 

sufficient to negate improved wastewater treatment. Because 

the project was innovative and funding was limited, only one 

impoundment was studied.

Part 2. Phosphorus Dynamics in a Wastewater-Dominated 

Impoundment, Hudson, Massachusetts

Introduction 41
Site Selection and Sample Collection

The Hudson impoundment was selected for this study 

because available data indicated that its summer ambient 

phosphorus concentrations were among the lowest of the 

six impoundments (ENSR International, 2001); substantial 

releases of phosphorus would be more easily detected there 

than in an impoundment with higher ambient concentrations. 

Furthermore, point sources and tributaries do not contribute 

significantly to streamflow in this impoundment during lowflow periods.

In this study, field measurements of water-column 

temperature, dissolved oxygen (DO), and specific conductance 

were made to determine the extent of hypoxia. In addition, 

samples were collected from multiple depths in the water 

column for analyses of chloride, ortho-, and total phosphorus; 

ortho- and total phosphorus samples were also collected from 

sediment pore water at selected sites. Different forms of phosphorus were analyzed to determine the proportion of labile 

(available for plant uptake) phosphate. Estimates of sediment 

phosphorus fluxes obtained in this way are inherently more 

realistic than measurements made under laboratory conditions. 

Thus, this approach was considered better than repeating the 

TMDL experiments on cores in the laboratory or measuring 

benthic phosphorus flux rates directly in the impoundments; 

the latter method would likely give a large range of flux rates 

and would also be prohibitively expensive.

Reconnaissance and Site Selection

One week before the start of the study, a reconnaissance 

consisting of preliminary measurements in the water column 

of DO, specific conductance, pH, and temperature was made 

at 37 locations to determine sites where sampling would most 

clearly reveal variations in the water quality. At all sites along 

the preimpoundment river channel, or thalweg, water-quality 

measurements showed no stratification. Some areas that did 

not lie along the thalweg, however, showed signs of potential stratification that could lead to anaerobic conditions and 

possibly phosphorus release.

Five sites were selected for use in this part of the study 

(fig. 17): one near the upstream end (17), one at the outlet 

(37); one off the main channel in a shallow embayment covered with Lemna (20); one in a deeper offchannel embayment 

with rooted macrophytes and some Lemna (27); and one in 

the middle of the impoundment off the main channel in dense, 

rooted macrophyte beds (29). All rooted macrophytes had 

heavy coatings of epiphytic algae. 

Field Measurements and Collection of 

Phosphorus and Chloride Samples

From July 16 to September 8, 2003, the Hudson 

impoundment was monitored once each week in a study to 

determine whether phosphorus release from sediments could 

be evaluated in spite of the high background concentrations. 

Each day, after the water-column-profile measurements were 

made, water samples for total phosphorus and orthophosphorus and chloride analyses were collected with a stainless-steel 

pushpoint sampler.

Water samples were collected from the water column 

at approximately 0.5-m or smaller intervals at five locations 

with a peristaltic pump attached to pushpoint samplers, stainless-steel rods about 1- or 2-m long that are screened at the 

tip. The pushpoint samplers are normally used for shallow 

ground-water sampling. For pore-water sampling, a platform 

was attached to the bottom of the sampler (fig. 18). When the 

platform was resting on the sediment surface, the screened 

tip of the sampler was stabilized at a depth of 5 cm below the 

surface.

Samples were analyzed for total phosphorus, dissolved 

phosphorus, and chloride by standard methods (Patten and 

Truitt, 1992; Fishman, 1993; Strickland and Parsons, 1968; 

Stauffer, 1983). Total phosphorus and chloride samples were 

analyzed by the USGS National Water Quality Laboratory, 

and orthophosphorus samples were analyzed in the USGS 

Massachusetts-Rhode Island Water Science Center office’s 

laboratory. Differences in phosphorus concentrations in 

samples from the main river channel and the backwater areas 

were examined to determine if there was a measurable net 

release of phosphorus from the sediments. The chloride served 

as a conservative tracer and check on the calculations of the 

phosphorus generation from the sediments; a larger upstream 

than downstream ratio of chloride to total phosphorus would 

suggest net phosphorus release in the impoundment. It was 

assumed that there were no unaccounted-for sources of 

chloride or water in the impoundment. 

Quality Control

To ensure quality control of the samples, replicate and 

blank samples were collected during the study (table 17, at 

back of report). Replicate samples demonstrated that the 

method yielded consistent results and supported their reliability. Field-blank analyses showed that neither the equipment 

nor the procedures employed caused any contamination of the 

samples that would lead to misinterpretation of data.

42 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Figure 17. Hudson, Massachusetts, impoundment with sampling sites for phosphorus-release dynamics study, July 

to September 2003.

Base map from MassGIS digital orthophoto,

NAD 83

0

0

500

150 300 METERS

1,000 FEET

27 29

37

EXPLANATION

SAMPLING SITE

71 ̊34'45" 71 ̊34'30" 71 ̊34'15"

42 ̊23'

42 ̊23'15"

42 ̊23'30"

17

20

20

Hudson Dam

Route 85

Park Steet

Footbridge

Site Selection and Sample Collection 43
Field Study of Phosphorus Dynamics

Vertical-profile data collected in 2003 at the five study 

sites in the Hudson impoundment for total phosphorus, 

orthophosphorus, and DO concentrations were plotted in 

relation to time and compared with rainfall data to reveal 

the relations among phosphorus concentrations in the water 

column and sediment, DO concentrations in the water column, 

and the effects of rainfall on total phosphorus storage in the 

impoundment (fig. 19). 

On the first sampling date, July 16, all field measurements indicated minimal, if any, stratification in the water 

column at any of the sampling stations (table 17; fig. 19). DO 

profiles were similar, too, with all concentrations approximately 6 to 7 mg/L. As the study period progressed, DO 

profiles at stations 17 and 37 demonstrated little stratification, 

while at stations 20, 27, and 29, DO concentrations frequently 

showed marked stratification. 

The mean total phosphorus concentrations of all watercolumn samples were approximately twice the orthophosphorus concentrations at each station (table 11). Mean total 

phosphorus and orthophosphorus concentrations were generally higher at the midimpoundment stations, 20, 27, and 29, 

than at 17 and 37. Station 20 had the highest mean total phosphorus and orthophosphorus concentrations, 0.3890 mg/L and 

0.155 mg/L, respectively. Medians of total phosphorus concentrations were also approximately twice the orthophosphorus 

median concentrations. The median total phosphorus concentrations, however, did not differ as much as the mean total 

phosphorus concentrations, and the median orthophos­phorus 

concentrations ranged only from 0.0550 to 0.0690 mg/L.

Total phosphorus and orthophosphorus concentrations in 

the sediment pore water were substantially higher than in the 

water column, with mean orthophosphorus concentrations several times greater than concentrations in the overlying water. 

The highest mean and median concentrations of orthophosphorus in sediment pore water were found at station 20, the 

shallowest station and the one where the surface was always 

covered with Lemna. 

Figure 18. Platform attached to pushpoint sampler in preparation for porewater sampling. The sampler’s screened tip protrudes through a hole in the 

bottom of the platform.

Table 11. Mean and median total phosphorus and orthophosphorus concentrations, in milligrams per liter, of all samples in 

the water column or pore water at each sampling station in the 

Hudson, Massachusetts, impoundment, July to September 2003.

Station 

number

Mean Median

Total

phosphorus

Ortho

phosphorus

Total

phosphorus

Ortho

phosphorus

Water Column

 17 0.1365 0.0687 0.1283 0.0550

 20 .3890 .1548 .1524 .0605

 27 .1483 .0839 .1209 .0660

 29 .1860 .0629 .1434 .0690

 37 .1246 .0676 .1122 .0590

Pore Water

 20 2.192 1.148 1.676 0.660

 27 .8381 .3244 .6540 .323

 29 1.245 .4309 1.2090 .271

44 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Site-Specific Profiles

At stations 17 and 37, the impoundment inflow and 

outflow stations, respectively, total phosphorus and orthophosphorus concentrations were approximately the same on any 

given date; total phosphorus generally ranged from 0.10 to 

0.15 mg/L and orthophosphorus concentrations were generally about two-thirds the concentration of the total. At station 

17, on September 8, the sample collected nearest the bottom 

had the highest concentration of total phosphorus at the site, 

0.4200 mg/L, and the DO concentration was 6.56 mg/L 

(table 17). The total phosphorus concentrations at station 

37 were particularly consistent, and indicated a well-mixed 

condition throughout the water column; on July 16, the bottom 

sample had a total phosphorus concentration of approximately 

0.3 mg/L; otherwise, concentrations were not greater than 

0.15 mg/L (fig. 19). 

At stations 20, 27, and 29, the bottom and pore-water 

phosphorus concentrations were higher and varied more with 

time than concentrations at other depths in the water column (fig. 19). The highest pore-water total phosphorus and 

orthophosphorus concentrations, approximately 5 and 7 mg/L, 

respectively, were detected on July 24 at station 20, where 

total phosphorus concentrations in the pore water had been 

measured as above 2 mg/L twice. At station 27, measured 

pore-water total phosphorus concentrations were higher than 

1 mg/L twice and were generally about 0.5 mg/L. At station 

29, total phosphorus concentrations in the pore water commonly approached or exceeded 1.0 mg/L. Phosphorus concentrations at the lowest levels of the water column and in the 

pore water did not appear to correlate well among the stations. 

Low DO concentrations in the water column did not correlate 

strongly with high phosphorus concentrations in the surface or 

pore waters. In addition, higher phosphorus concentrations in 

the samples taken from the greatest depth did not seem to be 

mirrored by increased concentrations elsewhere in the water 

column at any given station (fig. 19). This last finding indicated that phosphorus released from the sediments was taken 

up quickly, adsorbed onto particles, or precipitated when it 

entered the oxidized zone. 

In general, the phosphorus concentrations detected in this 

study were not as great as previously detected in the ENSR 

International (2001) study. Hydrologic conditions differed 

substantially between summers, with 2000 (the ENSR study) 

being extremely dry and 2003 (this USGS study) moderately 

wet. ENSR International cited discharges less than 0.57 m3/s, 

whereas discharges during the present study were about 

2.8 m3/s. The higher discharges in 2003 probably contributed to greater dilution of phosphorus, and probably affected 

flushing rates and stratification dynamics as well.

Changes in Phosphorus Storage

By combining the knowledge gained during the initial 

bathymetric mapping with the data obtained on phosphorus distribution in the water column, it was also possible to 

estimate the amount of phosphorus generated internally from 

the impounded sediment; that is, it was possible to calculate 

the mass of phosphorus at different depths within the water 

column to determine if increases were caused by sediment 

release. 

To examine the magnitude of phosphorus release 

throughout the impoundment during the study period, a 

geographic information system (GIS) was used to divide the 

bathymetric map into five sections, each represented by one of 

the stations in the study, and to estimate the volume of water 

in a series of 0.5-m-thick vertical layers in each section. The 

concentration of phosphorus in each layer was multiplied by 

the layer’s volume to give an estimate of the mass of phosphorus in that layer. The masses of phosphorus in the layers 

were added for each section, as were the sums for all sections, 

to give the total mass of phosphorus in the impoundment on a 

given sampling date. This series of estimates was intended to 

enable a visualization of the hydrologic effect of rainfall on the 

mass of phosphorus during the summer study period (table 12; 

fig. 19). Although rains fell frequently during the summer, 

there were no large storms with torrential rains, which could 

have destratified and flushed the impoundment. In addition, 

there were no extended drought-like periods. Storms in late 

July and early August seemed to precede increases in the mass 

of total phosphorus; possibly the increases were the result 

of nonpoint runoff. In August, the one period with frequent 

rainfall exhibited an increase in phosphorus mass and, after the 

rainy period ended, the mass of total phosphorus decreased. 

The rise could be a result of runoff and the drop may be 

attributable to dilution and flushing of phosphorus from the 

impoundment. Overall, the data acquired for this study and the 

estimated areas selected and delineated as representative of 

the conditions at the five sampling stations indicated no strong 

relations between rainfall and phosphorus mass. More frequent 

collection of samples, however, would be needed to establish a 

definite cause-and-effect relation between the two variables.

Field Study of Phosphorus Dynamics 45
7/14/2003 8/3/2003 

0

10

20

30

40

50

RAINFALL, IN MILLIMETERS

TOTAL PHOSPHORUS

RAINFALL

EXPLANATION

DISSOLVED OXYGEN

SEDIMENT-WATER

INTERFACE

TOTAL PHOSPHORUS

ORTHOPHOSPHORUS

0 0.1 0.2 0.3 0.4 0.5 0 0.1 0.2 0.3 0.4 0.5 0 0.1 0.2 0.3 0.4 0.5 

0

2

07/16/2003

0.5

1.0

1.5

07/24/2003 07/29/2003 

0 2 4 6

1.0

0

0.4

0.2

0.6

0.8

0 0.5 1.0 1.5 2.0 2.5 0 0.5 1.0 1.5 2.0 2.5 0 0.5 1.0 1.5 2.0 2.5 

8

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 

0 2 4 6 8 0 2 4 6 8 

8

0

0.5

1.0

1.5

0

0.5

1.0

1.5

0 0.5 1.0 1.5 2.0 0 0.5 1.0 1.5 2.0 0 0.5 1.0 1.5 2.0 

0 0.1 0.2 0.3 0 0.1 0.2 0.3 0 0.1 0.2 0.3 

0

1

2

3

0 2 4 6 8 10 12 0 2 4 6 8 10 12 0 2 4 6 8 10 12 

0 4 2 6 8 0 4 2 6 0 4 2 6 8 

0 2 4 6

0 2 4 6 8 10 0 2 4 6 8 10 0 2 4 6 8 10 

0 2 4 6 0 2 4 6 

Station 17 Station 20 Station 27 Station 29 Station 37

DEPTH, IN METERS

A.

B.

Figure 19. A, Total and 

orthophosphorus and dissolved 

oxygen water-column profiles 

at five stations in the Hudson 

impoundment, July to September 

2003. Depth is given as vertical 

distance from sediment surface 

to water surface. B, Rainfall and 

changes in estimated total phosphorus storage in the Hudson 

impoundment, July to September 

2003.

46 Sediment Studies in the Assabet River, Central Massachusetts, 2003
8/23/2003 9/12/2003

0

4

8

12

2003

TOTAL PHOSPHORUS AS P, 

IN KILOGRAMS

0 0.1 0.2 0.3 0.4 0.5 0 0.1 0.2 0.3 0.4 0.5 0 0.1 0.2 0.3 0.4 0.5 0 0.1 0.2 0.3 0.4 0.5 0 0.1 0.2 0.3 0.4 0.5

08/07/2003 08/13/2003 08/21/2003 08/28/2003 09/08/2003

0 0.5 1.0 1.5 2.0 2.5 0 0.5 1.0 1.5 2.0 2.5 0 0.5 1.0 1.5 2.0 2.5 0 0.5 1.0 1.5 2.0 2.5 0 0.5 1.0 1.5 2.0 2.5

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 4 6 80 2 4 6 8

0 0.5 1.0 1.5 2.0 0 0.5 1.0 1.5 2.0 0 0.5 1.0 1.5 2.0 0 0.5 1.0 1.5 2.0 0 0.5 1.0 1.5 2.0

0 0.1 0.2 0.3 0 0.1 0.2 0.3 0 0.1 0.2 0.3 0 0.1 0.2 0.3 0 0.1 0.2 0.3

0 2 4 6 8 10 12 0 2 4 6 8 10 12 0 2 4 6 8 10 12 0 2 4 6 8 10 12 0 2 4 6 8 10 12

0 4 2 6 8 0 4 2 6 8 0 4 2 6 8 0 4 2 6 8 0 4 2 6 8

0 2 4 6 8 10 0 2 4 6 8 10 0 2 4 6 8 10 0 2 4 6 8 10 0 2 4 6 8 10

0 2 4 6 0 2 4 6 0 2 4 6 0 2 4 6 0 2 4 6

PHOSPHORUS AS P, IN MILLIGRAMS PER LITER

DISSOLVED OXYGEN, IN MILLIGRAMS PER LITER

Field Study of Phosphorus Dynamics 47
Table 12. Estimated phosphorus storage in the Hudson, Massachusetts, impoundment sections, July to September 2003.

[m3, cubic meter]

Station number/

range

of layer

thickness

Layer 

volume

(m3)

Total phosphorus mass, in kilograms, on sampling date

 7-16-03 7-24-03 7-29-03 8-07-03 8-13-03 8-21-03 8-28-03 9-08-03

Station 17

0–0.5 15,000 1.52 2.18 1.27 2.28 2.05 1.58 1.23 1.23

0.5–1.0 9,400 .95 1.36 .80 1.43 1.28 .99 .77 .77

1.0–1.5 5,600 .60 .84 .48 .84 .76 .59 .59 1.40

1.5–2.0 2,200 .24 .35 .19 .33 .30 .23 .28 .92

2.0–2.3 220 .02 .03 .02 .03 .03 .02 .03 .09

Total 3.33 4.76 2.75 4.92 4.43 3.43 2.90 4.42

Station 20

0–0.5 4,000 0.42 0.30 0.31 0.40 0.29 0.39 0.23 0.22

0.5–1.0 3,100 .60 .51 .68 .47 .38 .47 .59 .66

1.0–1.5 340 .10 .09 1.06 .11 .06 .28 .11 .38

Total 1.11 0.90 2.05 0.98 0.73 1.13 0.93 1.27

Station 27

0– 0.5 5,100 0.49 0.61 0.65 0.70 0.07 0.59 0.53 0.38

0.5–1.0 7,400 .81 1.08 1.42 .93 .37 1.17 .76 .67

1.0–1.5 920 .11 .16 .24 .10 .08 .18 .23 .10

1.5–2.0 440 .05 .08 .11 .05 .04 .09 .17 .05

Total 1.47 1.92 2.43 1.79 0.56 2.04 1.69 1.20

Station 29

0– 0.5 3,900 0.28 0.43 0.30 0.56 0.50 0.62 0.31 0.36

0.5–1.0 1,900 .31 .40 .27 .28 .25 .31 .77 .22

1.0–1.5 590 .16 .18 .12 .09 .08 .10 .43 .08

Total 0.75 1.02 0.69 0.93 0.84 1.03 1.51 0.67

Station 37

0–0.5 9,200 0.91 1.26 0.84 1.40 1.29 0.95 0.80 0.74

0.5–1.0 7,900 .78 1.09 .72 1.21 1.12 .86 .64 .65

1.0–1.5 6,600 .66 .91 .60 1.01 .93 .76 .54 .56

1.5–2.0 3,200 .36 .44 .29 .50 .46 .38 .31 .28

2.0–2.5 900 .12 .13 .09 .14 .13 .02 .09 .08

2.5–2.8 90 .01 .01 .01 .01 .01 .01 .01 .01

Total 2.84 3.84 2.54 4.28 3.94 2.99 2.38 2.31

Total in all 

sections 9.49 12.44 10.46 12.90 10.50 10.62 9.42 9.88

48 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Mass Balance (Chloride:Total Phosphorus)

To determine whether there was a net export of phosphorus from the Hudson impoundment as a result of sediment 

release, the ratio of chloride to total phosphorus in the water 

column was traced during the study (table 13). With no known 

inputs of phosphorus or chloride besides inflowing water 

or sediment, sediment release would be expected to cause 

increases in total P concentrations and a lowering of the ratio. 

Comparison of the ratio for the upstream, influent site (station 

17) with the downstream outflow site (station 37) demonstrated no decreasing trend from upstream to downstream, as 

would be expected if sediments released phosphorus that was 

transported to the outflow; the values were not statistically 

different (p= 0.3551). This information suggests that there 

was no net gain of total phosphorus in the water column from 

the upstream to the downstream end of the impoundment. 

However, the data leave open the possibility that any phosphorus releases were rapidly cycled internally, either taken 

up by rooted or floating plant life or settled to the bottom as 

particulate matter.

Phosphorus Dynamics in the Hudson 

Impoundment

Phosphorus release from sediments is largely limited 

to those parts of the impoundment in which DO becomes 

depleted near the sediment-water interface; this depletion 

mainly occurs in offchannel areas where advection does not 

cause mixing. Because the temperature profiles do not indicate 

strong stratification, these low DO conditions probably do not 

persist for long periods of time; they may easily be disrupted 

by wind-induced mixing or light rain storms that increase 

local flows. The results of the phosphorus-dynamics study in 

the Hudson impoundment suggest that sediment release of 

phosphorus does not substantially affect the mass of phosphorus in the impoundment’s water column; from the hypoxic 

zone nearest the impoundment bottom, the DO concentrations 

increase toward the water surface. Two phenomena may prevent sediment phosphorus from mixing throughout the water 

column. First, high concentrations of nitrate may maintain 

high redox potentials and keep the iron in an oxidized state. 

Second, any phosphorus that is not taken up by plants after 

being released from the sediments may form colloids with iron 

hydroxides in the vicinity of the sediment-water interface; the 

precipitation of the colloids would inhibit phosphorus movement from sediments to the water column. However, the elevated mean and median concentrations of total phosphorus and 

orthophosphorus in the embayment areas of the impoundment 

in comparison to the main channel suggest that morphology 

and hydrodynamics play a large role in phosphorus dynamics in these impoundments. A more detailed phosphorusbudget study, including phosphorus transport and deposition 

and detailed analysis of the forms of phosphorus, might help 

define the effect of sediment phosphorus on the overall water 

quality in this and the other Assabet River impoundments.

Table 13. Ratios of chloride to total phosphorus at the inflow 

and outflow of the Hudson, Massachusetts, impoundment, July to 

September 2003.

Date Inflow

(station 17)

Outflow

(station 37)

7-24-03 810 890

7-29-03 1,700 1,600

8-07-03 720 720

8-13-03 820 820

8-21-03 1,200 1,200

8-28-03 2,000 1,700

9-08-03 1,800 1,800

Phosphorus Dynamics in the Hudson Impoundment 49
Summary

This study of the quantity, distribution, and chemistry 

of sediments in six impoundments on the Assabet River was 

undertaken during the summer and early fall of 2003 in cooperation with the Massachusetts Department of Environmental 

Protection and the U.S. Environmental Protection Agency. The 

results of the study provide information to enable managers, 

regulators, and other stakeholders to make informed decisions 

regarding the management of sediment to improve the river’s 

sediment and water quality. 

This two-part report provides the results of an assessment 

of the sediment extent and chemistry in six impoundments 

in the Assabet River and describes the study of the potential 

for the release of phosphorus from sediment to affect water 

quality in the Hudson impoundment. Obtaining data about the 

distribution of phosphorus in the sediments and the concentrations of phosphorus in the water column links the two parts 

of this study. Sediment volumes in the impoundments ranged 

from 380 cubic meters to 580,000 cubic meters. The interpretations of bulk-sediment chemistry data in this report include 

results of analyses for polycyclic (or polynuclear) aromatic 

hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), 

extractable petroleum hydrocarbons (EPH), reactive sulfide, 

and a selected group of metals and other elements, including 

phosphorus. Contract laboratories were unable to obtain data 

for organochlorine pesticides and volatile organic compounds 

(VOCs) because of matrix interference and sample dilution. 

The concentrations of these chemical constituents in the sediments are compared to standards for the disposal of dredged 

hazardous materials, for human contact, and for potential 

effects, including toxicity, on aquatic organisms.

The incidence of toxicity calculations show that approximately one third of the surficial sediment samples may be 

expected to have some toxic effect on test organisms. These 

effects may include mortality, diminished growth, and reduced 

reproductive capacity. Although the database used to estimate 

the incidence of toxicity did not contain results of toxicity 

testing for New England sediments, the calculated values 

are based on contaminant concentrations and should not 

be affected by regional differences. If no action is taken to 

mitigate the effects of sediment toxicity, efforts to restore the 

Assabet River may not be fully successful.

Bulk-sediment phosphorus concentrations generally 

decreased with depth below the sediment surface and generally increased in the downstream direction. Concentrations 

of phosphorus in the bulk-sediment samples ranged from less 

than 0.1 percent to 0.86 percent. If the amount of sediment 

removal required to deplete the mass of phosphorus to levels 

that will not adversely affect water-column concentrations 

of phosphorus can be calculated, then the bulk-sedimentphosphorus data should prove useful in mapping the areas to 

be dredged. However, the relations between bulk-sedimentphosphorus concentrations and phosphorus availability as 

an aquatic-plant nutrient have not been determined in the six 

impoundments that are the subjects of this study.

The analytical results of the first part of the study show 

that the distribution of potentially hazardous or toxic materials in the sediments is extremely complex. Concentrations of 

toxic metals, PAHs, and PCBs exceeded U.S. Environmental 

Protection Agency guidelines for the protection of aquatic life 

in most of the impoundments. PCBs were not detected only in 

the Hudson impoundment. The Powdermill impoundment had 

the largest number of contaminants exceeding Massachusetts 

Department of Environmental Protection guidelines for landfill 

disposal of sediments.

During the two-month period of the study of the Hudson 

impoundment, the water column in the areas of the impoundment studied did not stratify long enough to allow substantial amounts of phosphorus to be released from underlying 

sediments. High concentrations of nitrate in the water column 

may also have prevented favorable conditions for phosphorus 

release. A comparison of changes in phosphorus storage did 

not indicate that the total mass of phosphorus increased with 

time, only to be dispersed by storm-generated increases in 

streamflow; rather, there was a suggestion that increases in 

the calculated mass of phosphorus were associated with storm 

runoff into the impoundment. On the basis of the ratio of 

chloride to total phosphorus, changes in phosphorus concentrations in the stratified areas of the impoundment did not lead 

to increases in the mass of phosphorus in the water column 

and to increases in the net phosphorus transport out of the 

impoundment. This result indicates that phosphorus was either 

released from the sediments in less than measurable amounts 

or that it was absorbed quickly before it could be transported 

out of the impoundment. 

Acknowledgments

Successful completion of the mapping, sediment sampling field work, and sample processing could not have 

been accomplished without the assistance of the USGS 

Massachusetts-Rhode Island Water Science Center staff members David Armstrong, Lora Barlow, Kimberly Campo, Leslie 

DeSimone, Jonathan King, Paul Nardone, Lance Ostiguy, 

Vicki-Rose Siegel, Britt Stock, Bruce Taggart, and Marcus 

Waldron. USGS colleague reviewers Jonathan Morrison and 

John Colman made valuable technical recommendations that 

substantially improved this report. The entire staff of the 

Water Science Center’s Publications Unit — Mary Ashman, 

Mark Bonito, Matthew Cooke, Christine Mendelsohn, and 

Anne Weaver — is thanked for their patience and support. The 

Organization for the Assabet River not only enthusiastically 

encouraged this project, but also provided maps and insights 

that made our work easier.

50 Sediment Studies in the Assabet River, Central Massachusetts, 2003
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52 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Tables 14–17

Table 14. Concentrations of selected metals in sediment samples from six impoundments in the Assabet River Basin, Massachusetts, 

2003.—Continued

[Quantity in brackets is detection limit. All values are in milligrams per kilogram. Map ID: The identifier associated with a sampling site on a map 

(figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a 

replicate sample. NA, not applicable because of nondetects; <, actual value is less than value shown]

Map ID Sample ID Arsenic

[3]

Cadmium

[1]

Chromium

[1]

Copper

[0.5]

Lead

[2]

Nickel

[1]

Zinc

[0.5]

Aluminum City

AC1 5 5 1 145 309 85 22 183

AC2 7A 9 2 96 256 74 22 249

AC2 7B 9 3 124 768 182 28 397

AC2 7C 7 1 171 189 67 18 155

AC3 6A 10 2 145 286 95 22 278

AC3 6B 16 4 174 844 180 30 495

AC3 6C 15 2 183 362 238 24 296

AC4 8A 12 2 103 262 65 24 223

AC4 8B 7 2 153 502 78 24 291

AC4 8C 6 3 2,070 196 65 31 1,220

Mean 10 2 336 397 113 25 379

Median 9 2 149 298 82 24 285

Allen Street

AS5 1A 8 <1 177 42.9 84 17 211

AS5 1B 11 1 209 55.3 149 14 184

AS5 1C 10 <1 85 44.8 113 16 136

AS5 1D 6 <1 97 25.5 143 16 83.4

AS6 3A 11 4 142 515 229 33 487

AS6 3B 16 <1 224 53.7 150 19 182

AS6 3C 7 <1 149 16.9 58 17 78.3

AS7 2A 13 3 340 110 241 30 827

AS7 2B 11 3 242 59.2 146 18 474

AS7 2C 12 2 137 60.4 154 17 351

AS7 2D 8 <1 128 29.6 185 19 87.3

AS8 4A 12 2 152 188 90 24 281

AS8 4B 11 4 208 807 176 31 551

AS8 4C 12 3 158 300 201 27 515

AS8 4D 14 1 155 51.5 110 23 221

AS8 4E 9 <1 90 18 218 15 54

Mean 11 NA 168 149 153 21 295

Median 11 1 154 55 150 19 216

Hudson

H9 9 8 <1 129 12.7 12 14 35

H10 12A 15 2 104 119 324 41 212

H10 12B 20 2 130 78.9 243 24 300

H10 12C 8 <1 114 92.6 118 22 122

H10 12D 5 <1 28 8.2 8 8 14.6

H10 12E 9 <1 54 14.4 9 12 16

H11 13A 24 1 228 131 129 38 288

H11 13B 8 <1 164 7.2 12 14 19.4

H11 13C 27 <1 93 5.9 9 22 38.7

H11 13D 38 1 111 5.4 9 33 62.7

Tables 14–17 55
Table 14. Concentrations of selected metals in sediment samples from six impoundments in the Assabet River Basin, Massachusetts, 

2003.—Continued

[Quantity in brackets is detection limit. All values are in milligrams per kilogram. Map ID: The identifier associated with a sampling site on a map 

(figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a 

replicate sample. NA, not applicable because of nondetects; <, actual value is less than value shown]

Map ID Sample ID Arsenic

[3]

Cadmium

[1]

Chromium

[1]

Copper

[0.5]

Lead

[2]

Nickel

[1]

Zinc

[0.5]

Hudson—Continued

H12 11A 4 <1 155 7 6 20 28.1

H12 11B 3 <1 186 3.3 3 14 18.9

H13 14A 14 3 161 120 266 57 410

H13 14B 21 2 213 67.4 274 36 422

H13 14C 9 <1 304 22.9 146 29 66.1

H13 14D 5 <1 220 7.6 5 14 12.7

H13 14E 3 <1 144 4.3 4 11 16.2

H14 10A 9 <1 237 27.3 20 32 77

H14 10B 5 <1 134 4.1 6 12 20.7

H15 15A 20 2 208 141 283 86 406

H15 15B 25 1 193 96.1 218 29 365

H15 15C 17 <1 159 40.3 65 22 69

H15 15D 101 <1 85 3.4 20 11 21.8

Mean 17 NA 155 44 95 26 132

Median 9 <1 155 14 20 22 63

Gleasondale

G16 34A 4 <1 77 7.2 16 12 18.6

G16 34B <3 <1 127 8 13 16 32.1

G16 34C 3 <1 114 3.5 8 17 27.6

G17 39A 5 <1 173 8.2 6 16 29.2

G17 39B <3 <1 158 7.6 4 15 22.3

G17 39C 6 <1 155 9.5 4 16 28.5

G17 39D 6 <1 191 8.2 3 17 24.3

G18 35A 34 3 404 115 186 33 369

G18 35B 32 2 203 111 221 23 484

G18 35C 46 1 313 122 186 22 315

G18 35D 19 1 99 125 141 18 262

G18 35E 17 <1 333 128 125 22 180

G19 40A 19 12 326 261 254 91 464

G19 40B 75 3 195 162 232 26 518

G19 40C 50 2 257 144 198 24 358

G19 40D 7 <1 237 72 69 19 101

G19 40E 3 <1 209 5.6 4 12 19.6

G20 36A 7 <1 125 8.7 9 15 31.4

G20 36B 5 <1 118 7 6 14 24.2

G20 36C <3 <1 125 7.7 5 15 38.7

G20 36D 10 <1 112 13.2 6 18 31.2

G20 36E 41 1 39 38.8 5 28 93.8

G21 44 8 <1 373 24.8 30 22 71

G22 41A 17 7 284 405 233 149 485

G22 41B 20 3 367 102 145 44 248

56 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Table 14. Concentrations of selected metals in sediment samples from six impoundments in the Assabet River Basin, Massachusetts, 

2003.—Continued

[Quantity in brackets is detection limit. All values are in milligrams per kilogram. Map ID: The identifier associated with a sampling site on a map 

(figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a 

replicate sample. NA, not applicable because of nondetects; <, actual value is less than value shown]

Map ID Sample ID Arsenic

[3]

Cadmium

[1]

Chromium

[1]

Copper

[0.5]

Lead

[2]

Nickel

[1]

Zinc

[0.5]

Gleasondale—Continued

G22 41C 14 <1 409 81.6 87 22 142

G23 37A <3 <1 219 10.2 17 15 31.7

G23 37B 7 <1 246 9.2 12 13 36.8

G23 37C 5 <1 192 17.7 23 13 47.6

G23 37D 14 <1 286 153 147 23 191

G24 42A 14 <1 101 7.1 20 17 33.7

G24 42B 9 <1 149 4.6 9 17 25.3

G25 45 5 <1 223 7 9 11 23.7

G26 38A 11 <1 64 7.9 11 9 15

G26 38B 16 <1 96 10.7 8 9 15.9

G26 38C 16 <1 194 7.8 4 24 34.2

G27 43 7 <1 295 33.3 66 24 84.2

Mean 17 NA 205 61 68 24 134

Median 11 <1 194 11 16 17 37

Ben Smith

BS28 16A 9 <1 157 23.2 30 20 82.8

BS28 16B 8 <1 195 11.4 15 15 50.1

BS29 18A 7 <1 157 19.2 26 14 43.9

BS29 18B 6 <1 100 5.4 13 9 5.7

BS29 18C 5 <1 174 3.5 12 16 9.8

BS30 17A 24 7 293 201 204 98 515

BS30 17B 52 3 250 118 188 31 617

BS30 17C 64 3 353 128 179 31 637

BS30 17D 18 <1 241 102 95 23 165

BS30 17E <3 <1 79 5.8 10 8 3.2

BS31 19A 82 2 397 121 178 32 479

BS31 19B 35 <1 298 167 166 29 281

BS31 19C 17 <1 210 72.6 74 23 112

BS31 19D 5 <1 197 7.5 9 20 21.6

BS31 19E 6 <1 236 8.3 6 22 16.8

BS32 20A 17 7 170 318 192 132 492

BS32 20B 35 5 173 124 263 36 481

BS32 20C 6 <1 116 14.8 12 16 34.4

BS32 20D 6 <1 48 9.4 6 12 23

BS32 20E 9 <1 165 10.6 6 19 29.8

BS33 21A 35 2 179 123 144 26 334

BS33 21B 8 <1 85 14.4 20 16 30.9

BS33 21C 4 <1 85 7.5 8 14 21.6

BS33 21D 4 <1 132 8.9 7 17 25.1

BS33 21E 3 <1 151 8.3 6 16 26.6

Tables 14–17 57
Table 14. Concentrations of selected metals in sediment samples from six impoundments in the Assabet River Basin, Massachusetts, 

2003.—Continued

[Quantity in brackets is detection limit. All values are in milligrams per kilogram. Map ID: The identifier associated with a sampling site on a map 

(figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a 

replicate sample. NA, not applicable because of nondetects; <, actual value is less than value shown]

Map ID Sample ID Arsenic

[3]

Cadmium

[1]

Chromium

[1]

Copper

[0.5]

Lead

[2]

Nickel

[1]

Zinc

[0.5]

Ben Smith—Continued

BS34 22A 34 7 249 175 213 59 484

BS34 22B 9 <1 195 15.4 18 15 38.3

BS34 22C <3 <1 94 6.6 7 14 19.4

BS35 23A 39 3 175 116 160 47 446

BS35 23B 61 2 213 101 164 27 458

BS35 23C 11 <1 135 18.9 72 15 37.5

BS36 27A 8 <1 58 3.9 10 14 26.4

BS36 27B 19 <1 176 4 10 18 27.8

BS36 27C 55 <1 88 3.2 12 18 26.8

BS36 27D 82 <1 54 2.7 11 14 24.2

BS37 29A 17 <1 152 23.2 32 16 62.2

BS37 29B 8 <1 99 2.2 10 12 18.4

BS37 29C 4 <1 130 1.7 11 13 18.7

BS38 26A 71 4 160 131 3,800 46 483

BS38 26B 59 2 245 122 160 28 390

BS38 26C 19 <1 167 67.8 80 22 110

BS38 26D 11 <1 147 5.8 13 23 13.7

BS38 26E 9 <1 75 5.1 10 28 44.6

BS39 25A 17 <1 184 13.6 25 25 53.7

BS39 25B 11 <1 246 11.1 11 26 29

BS40 24A 14 <1 216 13.4 16 27 36.9

BS40 24B 8 <1 130 3.5 8 17 23.8

BS40 24C 14 <1 151 4.6 9 25 27

BS41 28A 14 <1 237 4.5 8 18 23.4

BS41 28B 83 <1 91 2.7 14 18 22.3

BS42 33A 12 <1 239 38.6 50 21 81.1

BS42 33B 10 <1 383 41.2 29 19 43.4

BS43 30A 21 5 132 167 160 68 386

BS43 30B 41 4 182 117 157 47 422

BS43 30C 36 <1 167 94.2 125 22 213

BS43 30D 19 <1 140 21.4 32 17 47

BS43 30E 8 <1 94 2.8 11 11 13.3

BS44 31A 6 <1 254 5.5 5 12 16.6

BS44 31B 5 <1 271 11.7 18 11 22.6

BS45 32A <3 <1 180 3.8 3 11 14.9

BS45 32B 4 <1 228 10.3 8 14 18.9

Mean 22 NA 177 49 121 25 144

Median 13 <1 170 13 16 19 37

58 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Table 14. Concentrations of selected metals in sediment samples from six impoundments in the Assabet River Basin, Massachusetts, 

2003.—Continued

[Quantity in brackets is detection limit. All values are in milligrams per kilogram. Map ID: The identifier associated with a sampling site on a map 

(figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a 

replicate sample. NA, not applicable because of nondetects; <, actual value is less than value shown]

Map ID Sample ID Arsenic

[3]

Cadmium

[1]

Chromium

[1]

Copper

[0.5]

Lead

[2]

Nickel

[1]

Zinc

[0.5]

Powdermill

P46 48 21 2 899 280 233 40 289

P47 49 8 <1 394 50.9 110 30 152

P48 46A 34 1 1,290 257 259 26 162

P48 46B 20 <1 238 31.6 23 31 75.2

P48 46C 62 <1 129 17.2 11 45 47

P49 47 5 <1 268 19.4 58 27 59.3

P50 52A 15 2 272 109 231 54 331

P50 52B 13 2 339 123 261 77 298

P50 52C 11 1 311 78.3 244 41 183

P50 52D 22 4 478 128 174 35 306

P50 52E 36 <1 291 55 318 20 93.2

P51 55A 31 5 1,060 839 594 60 1,140

P51 55B 58 3 1,830 386 343 24 1,010

P51 55C <3 <1 97 22.4 12 51 10.8

P51 55D 6 <1 128 40 7 52 17.5

P52 53A 16 2 399 100 167 56 354

P52 53B 13 4 404 184 371 53 339

P52 53C 101 7 2,270 330 621 29 726

P52 53D 20 <1 421 194 115 21 163

P52 53E 10 <1 302 26.8 71 25 44.8

P53 56A 18 6 416 669 580 272 379

P53 56B 47 4 1,550 277 515 54 424

P53 56C 66 8 1,970 545 419 26 1,010

P54 54A 44 7 1,530 3430 1,030 69 905

P54 54B 6 <1 148 49.8 29 14 388

P54 54C <3 <1 106 14.6 14 10 62.6

P55 51A 9 <1 248 78 54 46 99.6

P55 51B 6 <1 179 10.5 11 21 33.2

P55 51C 9 <1 173 6.2 7 22 31.4

P55 51D 6 <1 274 5.5 7 29 28.7

P55 51E 4 <1 240 5.9 7 30 29.3

P56 50A 17 6 332 720 411 179 572

P56 50B 28 10 786 910 1,250 84 1,200

P56 50C 48 9 1,320 459 305 28 703

P56 50D 9 <1 187 23.7 40 26 48.2

P56 50E <3 <1 221 9.1 7 13 10.3

P57 57 <3 <1 272 18 45 30 66.9

Mean 25 NA 588 284 242 47 319

Median 17 <1 311 78 167 30 163

Tables 14–17 59
Table 15. Results of all elemental analyses performed by SGS Canada, Inc., Mineral Services, Toronto, Ontario, Canada, of sediment samples from six impoundments in the 

Assabet River Basin, Massachusetts, 2003.—Continued[Quantity in brackets is detection limit. Map ID: The identifier associated with a sampling site on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a replicate sample; DUP, SGS laboratory duplicate quality-control sample. %, percent; ppm, parts per million; <, actual value is less than value shown; --, not reported]

Map ID Sample ID

Aluminum

(%)

[0.01]

Antimony

(ppm) 

[5]

Arsenic

(ppm) 

[3]

Barium

(ppm) 

[1]

Beryllium

(ppm) 

[0.5]

Bismuth

(ppm) 

[5]

Cadmium

(ppm) 

[1]

Calcium

(%)

[0.01]

Chromium

(ppm) 

[1]

Cobalt

(ppm) 

[1]

Copper

(ppm) 

[0.5]

Iron

(%)

[0.01]

Lanthanum

(ppm) 

[0.5]

Lead

(ppm) 

[2]

Lithium

(ppm) 

[1]

Magnesium

(%)

[0.01]

Aluminum City

AC1 5 1.12 <5 5 137 <0.5 <5 1 0.35 145 9 309 1.87 15.4 85 2 0.45AC2 7A 1.2 <5 9 210 <.5 <5 2 .55 96 11 256 1.75 15.5 74 1 .36AC2 7B 1.28 <5 9 230 .8 8 3 .53 124 11 768 1.87 15.6 182 2 .41AC2 7C 1.25 <5 7 154 <.5 <5 1 .55 171 12 189 1.5 10.4 67 <1 .29AC3 6A 1.15 <5 10 162 <.5 <5 2 .46 145 10 286 1.63 15.6 95 <1 .34AC3 6B 1.47 <5 16 198 .6 9 4 .49 174 13 844 2.15 18.1 180 5 .45AC3 6C 1.35 <5 15 247 .5 <5 2 .41 183 16 362 2.2 16.4 238 3 .43AC4 8A 1.21 <5 12 193 .5 <5 2 .43 103 11 262 1.51 15.2 65 2 .36AC4 8B 1.17 <5 7 166 <.5 <5 2 .41 153 12 502 1.62 14.1 78 <1 .36AC4 8B-DUP 1.14 <5 6 169 <.5 <5 2 .41 150 12 501 1.6 13.9 78 1 .35AC4 8C .96 6 6 135 <.5 <5 3 .29 2,070 13 196 1.68 11.1 65 <1 .35

Allen Street

AS5 1A 0.87 <5 8 71 <0.5 <5 <1 0.23 177 8 42.9 1.48 10.4 84 <1 0.34AS5 1A-DUP .83 <5 9 69 <.5 <5 <1 .23 172 7 42.7 1.43 10.7 80 <1 .32AS5 1B .77 <5 11 68 <.5 <5 1 .29 209 6 55.3 1.16 9.2 149 <1 .28AS5 1C .94 <5 10 74 <.5 <5 <1 .23 85 11 44.8 1.47 11.7 113 <1 .35AS5 1D .89 <5 6 63 <.5 <5 <1 .2 97 8 25.5 1.37 10.4 143 <1 .34AS6 3A 1.4 <5 11 265 .6 <5 4 .52 142 21 515 1.93 17.2 229 3 .44AS6 3B .99 <5 16 90 <.5 <5 <1 .29 224 11 53.7 1.46 12.4 150 <1 .34AS6 3C 1.25 <5 7 62 .5 <5 <1 .21 149 8 16.9 1.45 13.6 58 <1 .3AS7 2A 1.36 <5 13 176 <.5 <5 3 .39 340 18 110 2.35 15.6 241 1 .43AS7 2B .95 <5 11 90 <.5 <5 3 .23 242 10 59.2 1.46 12.7 146 <1 .34AS7 2C 1.01 <5 12 88 <.5 <5 2 .28 137 10 60.4 1.5 13.2 154 <1 .33AS7 2D 1.12 <5 8 74 <.5 <5 <1 .23 128 10 29.6 1.39 14 185 <1 .38AS8 4A 1 <5 12 183 <.5 <5 2 .5 152 13 188 1.93 13.8 90 <1 .32AS8 4B 1.29 <5 11 265 .6 8 4 .51 208 14 807 2 16.9 176 <1 .39AS8 4B-DUP 1.28 <5 11 275 .7 8 4 .49 224 15 820 2.05 17.6 185 3 .43AS8 4C 1.17 <5 12 210 .5 <5 3 .4 158 18 300 1.83 14.5 201 <1 .37AS8 4D 1.37 <5 14 87 <.5 <5 1 .28 155 14 51.5 1.86 15.4 110 4 .47AS8 4E 1.02 <5 9 55 <.5 <5 <1 .33 90 6 18 1.12 11.6 218 <1 .32

60 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Table 15. Results of all elemental analyses performed by SGS Canada, Inc., Mineral Services, Toronto, Ontario, Canada, of sediment samples from six impoundments in the 

Assabet River Basin, Massachusetts, 2003.—Continued[Quantity in brackets is detection limit. Map ID: The identifier associated with a sampling site on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a replicate sample; DUP, SGS laboratory duplicate quality-control sample. %, percent; ppm, parts per million; <, actual value is less than value shown; --, not reported]

Map ID Sample ID

Aluminum

(%)

[0.01]

Antimony

(ppm) 

[5]

Arsenic

(ppm) 

[3]

Barium

(ppm) 

[1]

Beryllium

(ppm) 

[0.5]

Bismuth

(ppm) 

[5]

Cadmium

(ppm) 

[1]

Calcium

(%)

[0.01]

Chromium

(ppm) 

[1]

Cobalt

(ppm) 

[1]

Copper

(ppm) 

[0.5]

Iron

(%)

[0.01]

Lanthanum

(ppm) 

[0.5]

Lead

(ppm) 

[2]

Lithium

(ppm) 

[1]

Magnesium

(%)

[0.01]

Hudson

H9 9 0.83 <5 8 36 1.3 <5 <1 0.25 129 4 12.7 0.63 19.7 12 <1 0.11H10 12A 1.34 <5 15 157 .6 <5 2 .26 104 12 119 1.69 15 324 2 .42H10 12B 1.39 <5 20 111 .6 <5 2 .18 130 13 78.9 1.63 15.3 243 2 .37H10 12C 1.86 <5 8 102 .6 <5 <1 .18 114 12 92.6 1.83 18.8 118 6 .51H10 12D .58 <5 5 33 .5 <5 <1 .33 28 4 8.2 .76 13.6 8 <1 .1H10 12E 1.33 <5 9 29 3.4 <5 <1 .2 54 4 14.4 .86 148 9 <1 .19H11 13A 1.19 <5 24 93 .6 <5 1 .3 228 24 131 1.66 14 129 <1 .27H11 13A-DUP 1.19 <5 26 98 .5 <5 2 .28 222 26 138 1.59 15 134 2 .25H11 13B 1.1 <5 8 37 .7 <5 <1 .25 164 12 7.2 1.21 30.8 12 <1 .16H11 13C 2.08 <5 27 36 1.7 <5 <1 .23 93 31 5.9 2.45 38.7 9 3 .36H11 13D 2.19 <5 38 122 .8 <5 1 .11 111 38 5.4 3.25 21.2 9 10 .52H12 11A .78 <5 4 37 <.5 <5 <1 .14 155 7 7 1.03 11.4 6 <1 .22H12 11B .78 <5 3 27 <.5 <5 <1 .09 186 6 3.3 1.15 15.3 3 <1 .24H13 14A 1.27 <5 14 109 .7 8 3 .67 161 15 120 2.37 15.6 266 13 .34H13 14A-DUP 1.26 <5 14 119 .7 <5 3 .68 153 13 125 2.25 15.7 264 14 .34H13 14AQ 1.33 <5 15 114 .7 <5 2 .66 180 16 130 2.49 14.8 279 14 .36H13 14B 1.6 <5 21 81 .7 <5 2 .6 213 14 67.4 2.46 14.4 274 18 .43H13 14BQ 1.59 <5 19 78 .7 <5 2 .56 227 14 69 2.43 14.1 247 19 .44H13 14C 1.1 <5 9 41 <.5 <5 <1 .28 304 7 22.9 1.7 9.3 146 17 .42H13 14CQ 1.15 <5 8 47 <.5 <5 <1 .26 287 7 22.5 1.78 9.3 234 18 .46H13 14D .39 <5 5 18 <.5 <5 <1 .81 220 3 7.6 .56 7.8 5 2 .12H13 14DQ .43 <5 4 20 <.5 <5 <1 .83 298 2 9.9 .64 7.6 8 3 .12H13 14E .84 <5 3 20 <.5 <5 <1 .23 144 3 4.3 .92 12.1 4 12 .25H13 14EQ .85 <5 3 20 <.5 <5 <1 .2 223 2 5.5 1.01 12.1 5 12 .26H14 10A .79 <5 9 88 <.5 <5 <1 .35 237 11 27.3 1.44 11.3 20 <1 .22H14 10B .76 <5 5 30 <.5 <5 <1 .14 134 6 4.1 .93 17 6 <1 .2H15 15A 1.77 <5 20 250 1 <5 2 .46 208 33 141 3.1 16.4 283 20 .46H15 15B 1.93 <5 25 119 .9 <5 1 .42 193 19 96.1 2.47 16.6 218 23 .47H15 15C 1.53 <5 17 71 .7 <5 <1 .36 159 15 40.3 2.5 12.4 65 16 .31H15 15C-DUP 1.46 <5 16 71 .7 <5 <1 .36 147 13 38.6 2.36 13.4 61 16 .3H15 15D 2 <5 101 43 1.5 10 <1 .14 85 14 3.4 8.78 11.7 20 15 .26

Tables 14–17 61
Table 15. Results of all elemental analyses performed by SGS Canada, Inc., Mineral Services, Toronto, Ontario, Canada, of sediment samples from six impoundments in the 

Assabet River Basin, Massachusetts, 2003.—Continued[Quantity in brackets is detection limit. Map ID: The identifier associated with a sampling site on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a replicate sample; DUP, SGS laboratory duplicate quality-control sample. %, percent; ppm, parts per million; <, actual value is less than value shown; --, not reported]

Map ID Sample ID

Aluminum

(%)

[0.01]

Antimony

(ppm) 

[5]

Arsenic

(ppm) 

[3]

Barium

(ppm) 

[1]

Beryllium

(ppm) 

[0.5]

Bismuth

(ppm) 

[5]

Cadmium

(ppm) 

[1]

Calcium

(%)

[0.01]

Chromium

(ppm) 

[1]

Cobalt

(ppm) 

[1]

Copper

(ppm) 

[0.5]

Iron

(%)

[0.01]

Lanthanum

(ppm) 

[0.5]

Lead

(ppm) 

[2]

Lithium

(ppm) 

[1]

Magnesium

(%)

[0.01]

Gleasondale

G16 34A 1.04 <5 4 51 <0.5 <5 <1 0.39 77 4 7.2 0.65 11.9 16 11 0.2G16 34B 1.39 <5 <3 54 .6 <5 <1 .29 127 6 8 .98 17 13 19 .32G16 34C 1.48 <5 3 57 .6 <5 <1 .2 114 6 3.5 1.03 19.1 8 22 .4G16 34C-DUP 1.38 <5 <3 54 .6 <5 <1 .2 107 6 3.5 .97 18.1 8 21 .38G17 39A .94 <5 5 38 <.5 <5 <1 .11 173 5 8.2 1.69 1.6 6 22 .42G17 39B .75 <5 <3 35 <.5 <5 <1 .13 158 5 7.6 1.16 9.8 4 14 .35G17 39C .93 <5 6 37 <.5 <5 <1 .24 155 5 9.5 1.36 12.2 4 16 .4G17 39D .81 <5 6 35 <.5 <5 <1 .12 191 4 8.2 1.3 9.6 3 18 .37G18 35A 1.29 <5 34 125 .7 <5 3 .33 404 22 115 2.26 16.4 186 15 .34G18 35B 1.41 <5 32 128 .7 <5 2 .29 203 15 111 1.88 16.6 221 16 .36G18 35C 1.45 <5 46 115 .7 <5 1 .3 313 13 122 1.89 16.8 186 16 .38G18 35D 1.32 <5 19 132 .5 <5 1 .36 99 11 125 1.49 13.7 141 16 .38G18 35E 1.44 <5 17 91 .6 <5 <1 .29 333 13 128 1.85 16.6 125 18 .39G19 40A 1.43 <5 19 264 1.3 <5 12 .55 326 47 261 3.11 17.5 254 15 .35G19 40B 1.51 <5 75 142 .7 <5 3 .45 195 16 162 2.18 14.5 232 15 .38G19 40B-DUP 1.47 <5 71 140 .8 <5 3 .45 192 16 160 2.13 14.9 228 15 .37G19 40C 1.52 <5 50 128 .7 <5 2 .44 257 14 144 2.02 16.6 198 17 .42G19 40CQ 1.51 <5 47 124 .7 <5 2 .44 309 14 141 2.05 16.3 191 17 .41G19 40D .96 <5 7 60 <.5 <5 <1 .23 237 10 72 1.4 11.4 69 14 .31G19 40E .54 <5 3 28 <.5 <5 <1 .09 209 3 5.6 .96 9 4 11 .23G20 36A 1.04 <5 7 53 <.5 <5 <1 .32 125 4 8.7 1.13 11.9 9 18 .32G20 36AQ 1.05 <5 4 65 <.5 <5 <1 .32 554 6 13.8 1.55 15.6 11 15 .27G20 36B .91 <5 5 51 <.5 <5 <1 .33 118 6 7 .92 11.6 6 12 .25G20 36C 1.04 <5 <3 61 <.5 <5 <1 .3 125 8 7.7 1.12 12.8 5 15 .29G20 36D .84 <5 10 52 <.5 <5 <1 .43 112 11 13.2 1.36 13.4 6 10 .21G20 36E .6 <5 41 50 <.5 <5 1 .94 39 23 38.8 2.4 21.3 5 2 .08G21 44 .68 <5 8 64 <.5 <5 <1 .2 373 7 24.8 1.66 8.2 30 11 .22G22 41A 1.51 <5 17 351 1.2 <5 7 .6 284 32 405 3.39 16.7 233 17 .37G22 41B 1 <5 20 114 .5 <5 3 .29 367 19 102 1.87 11.3 145 14 .28G22 41C 1.15 <5 14 81 <.5 <5 <1 .32 409 11 81.6 1.88 12.8 87 15 .34

62 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Table 15. Results of all elemental analyses performed by SGS Canada, Inc., Mineral Services, Toronto, Ontario, Canada, of sediment samples from six impoundments in the 

Assabet River Basin, Massachusetts, 2003.—Continued[Quantity in brackets is detection limit. Map ID: The identifier associated with a sampling site on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a replicate sample; DUP, SGS laboratory duplicate quality-control sample. %, percent; ppm, parts per million; <, actual value is less than value shown; --, not reported]

Map ID Sample ID

Aluminum

(%)

[0.01]

Antimony

(ppm) 

[5]

Arsenic

(ppm) 

[3]

Barium

(ppm) 

[1]

Beryllium

(ppm) 

[0.5]

Bismuth

(ppm) 

[5]

Cadmium

(ppm) 

[1]

Calcium

(%)

[0.01]

Chromium

(ppm) 

[1]

Cobalt

(ppm) 

[1]

Copper

(ppm) 

[0.5]

Iron

(%)

[0.01]

Lanthanum

(ppm) 

[0.5]

Lead

(ppm) 

[2]

Lithium

(ppm) 

[1]

Magnesium

(%)

[0.01]

Gleasondale—Continued

G23 37A 0.53 <5 <3 45 <0.5 <5 <1 0.08 219 4 10.2 1.01 7.8 17 10 0.2G23 37A-DUP .54 <5 3 44 <.5 <5 <1 .08 226 3 10.2 1.02 8.5 18 10 .21G23 37B .57 <5 7 38 <.5 <5 <1 .09 246 4 9.2 1.16 8 12 11 .22G23 37C .52 <5 5 42 <.5 <5 <1 .19 192 4 17.7 .97 7.9 23 9 .2G23 37D 1.4 <5 14 114 .6 <5 <1 .44 286 10 153 1.72 16 147 18 .39G24 42A 1.55 <5 14 43 .7 <5 <1 .1 101 14 7.1 2.33 17.2 20 20 .32G24 42B 1.21 <5 9 42 .6 <5 <1 .08 149 7 4.6 1.72 21 9 19 .29G25 45 .53 <5 5 30 <.5 <5 <1 .06 223 3 7 1.06 9.6 9 12 .21G25 45-DUP .53 <5 3 30 <.5 <5 <1 .06 215 3 6.9 1.03 9.4 9 12 .21G26 38A .82 <5 11 45 .5 <5 <1 .77 64 2 7.9 .64 10.9 11 8 .19G26 38B .6 <5 16 34 <.5 <5 <1 .66 96 2 1.7 .62 7.6 8 5 .15G26 38C .93 <5 16 39 <.5 <5 <1 .45 194 18 7.8 1.23 10.5 4 14 .28G27 43 .62 <5 7 77 <.5 <5 <1 .15 295 8 33.3 1.48 8.4 66 10 .22

Ben Smith

BS28 16A 0.6 <5 9 47 <0.5 <5 <1 0.13 157 13 23.2 1.11 7.1 30 9 0.2BS28 16B .78 <5 8 35 <.5 <5 <1 .07 195 9 11.4 1.45 9.2 15 13 .31BS29 18A 1.03 <5 7 62 2.3 <5 <1 .51 157 4 19.2 .94 50.3 26 3 .07BS29 18B 1.08 <5 6 47 2.5 <5 <1 .44 100 3 5.4 .79 61.2 13 2 .05BS29 18C 1.72 <5 5 36 3.6 <5 <1 .15 174 2 3.5 .79 112 12 9 .15BS29 19A 1.49 <5 82 154 .8 <5 2 .39 397 31 121 2.44 16 178 14 .32BS30 17A 1.43 <5 24 209 1 <5 7 .45 293 41 201 2.58 15.2 204 15 .33BS30 17B 1.46 <5 52 131 .8 5 3 .43 250 24 118 2.28 14.7 188 14 .31BS30 17C 1.55 <5 64 127 .8 <5 3 .4 353 28 128 2.14 16.5 179 15 .32BS30 17D 1.35 <5 18 85 .7 <5 <1 .38 241 19 102 1.44 14.8 95 11 .23BS30 17E .94 <5 <3 26 .9 <5 <1 .31 79 3 5.8 .39 28.5 10 2 .03BS31 19A-DUP 1.42 <5 69 152 .8 <5 3 .4 381 26 115 2.24 16.4 168 14 .3BS31 19AQ 1.46 <5 78 151 .8 <5 2 .38 432 29 123 2.41 15.4 174 14 .32BS31 19B 1.61 <5 35 141 .8 <5 <1 .36 298 27 167 2.16 16.3 166 16 .34BS31 19BQ 1.58 <5 37 137 .8 <5 <1 .36 366 27 165 2.19 16.3 165 15 .33

Tables 14–17 63
Table 15. Results of all elemental analyses performed by SGS Canada, Inc., Mineral Services, Toronto, Ontario, Canada, of sediment samples from six impoundments in the 

Assabet River Basin, Massachusetts, 2003.—Continued[Quantity in brackets is detection limit. Map ID: The identifier associated with a sampling site on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a replicate sample; DUP, SGS laboratory duplicate quality-control sample. %, percent; ppm, parts per million; <, actual value is less than value shown; --, not reported]

Map ID Sample ID

Aluminum

(%)

[0.01]

Antimony

(ppm) 

[5]

Arsenic

(ppm) 

[3]

Barium

(ppm) 

[1]

Beryllium

(ppm) 

[0.5]

Bismuth

(ppm) 

[5]

Cadmium

(ppm) 

[1]

Calcium

(%)

[0.01]

Chromium

(ppm) 

[1]

Cobalt

(ppm) 

[1]

Copper

(ppm) 

[0.5]

Iron

(%)

[0.01]

Lanthanum

(ppm) 

[0.5]

Lead

(ppm) 

[2]

Lithium

(ppm) 

[1]

Magnesium

(%)

[0.01]

Ben Smith—Continued

BS31 19C 1.42 <5 17 86 0.6 <5 <1 0.28 210 21 72.6 1.67 14.1 74 14 0.27BS31 19CQ 1.43 <5 15 85 .6 <5 <1 .28 220 22 64.6 1.65 14.2 71 14 .27BS31 19D 1.28 <5 5 54 <.5 <5 <1 .16 197 7 7.5 1.27 15.8 9 15 .28BS31 19DQ 1.18 <5 5 50 <.5 <5 <1 .16 165 7 7.9 1.25 13.9 11 14 .28BS31 19E 1.09 <5 6 54 <.5 <5 <1 .19 236 6 8.3 1.11 14.1 6 13 .23BS31 19EQ 1.12 <5 5 55 <.5 <5 <1 .21 190 7 8.6 1.18 14.2 6 14 .28BS32 20A 1.41 <5 17 415 1.1 <5 7 .54 170 48 318 3.71 15 192 14 .3BS32 20B 1.38 <5 35 194 .8 <5 5 .48 173 34 124 2.34 13.7 263 14 .3BS32 20C .81 <5 6 73 <.5 <5 <1 .57 116 9 14.8 1.07 10.9 12 7 .17BS32 20C-DUP .76 <5 6 71 <.5 <5 <1 .57 110 7 13.9 .99 10.8 11 7 .16BS32 20D .77 <5 6 65 <.5 <5 <1 .5 48 11 9.4 .93 12.3 6 5 .12BS32 20E .75 <5 9 60 <.5 <5 <1 .41 165 12 10.6 1.12 11.3 6 6 .15BS33 21A 1.54 <5 35 121 1 <5 2 .43 179 29 123 1.95 14.5 144 15 .3BS33 21B 1.36 <5 8 71 .6 <5 <1 .32 85 9 14.4 1.22 14.1 20 14 .27BS33 21C 1.18 <5 4 65 <.5 <5 <1 .31 85 8 7.5 1.1 13.7 8 14 .26BS33 21D 1.09 <5 4 68 .5 <5 <1 .36 132 9 8.9 1.15 13.3 7 13 .26BS33 21E 1.08 <5 3 67 <.5 <5 <1 .34 151 8 8.3 1.25 13.3 6 14 .28BS34 22A 1.44 <5 34 187 1 <5 7 .32 249 40 175 2.13 15.4 213 12 .28BS34 22B .89 <5 9 35 <.5 <5 <1 .18 195 5 15.4 1.02 12.4 18 12 .23BS34 22C .76 <5 <3 23 <.5 <5 <1 .09 94 2 6.6 .96 11.4 7 14 .29BS35 23A 1.23 <5 39 149 .8 5 3 .37 175 31 116 2.38 13.3 160 11 .24BS35 23B 1.32 <5 61 89 .8 <5 2 .34 213 27 101 1.93 14.7 164 11 .22BS35 23B-DUP 1.27 <5 56 89 .7 <5 2 .35 206 24 100 1.83 14.2 159 10 .22BS35 23C 1.19 <5 11 41 .9 <5 <1 .29 135 6 18.9 1.34 21.3 72 12 .18BS36 27A 1.4 <5 8 43 .7 <5 <1 .19 58 12 3.9 1.67 17.2 10 17 .31BS36 27B 1.86 <5 19 43 1.2 <5 <1 .15 176 26 4 2.71 26 10 22 .37BS36 27C 1.72 <5 55 39 1.2 <5 <1 .13 88 25 3.2 4.78 25.3 12 23 .37BS36 27D 1.32 <5 82 37 1 <5 <1 .1 54 41 2.7 6.12 19.1 11 21 .32BS36 27D-DUP 1.26 <5 78 36 1 <5 <1 .1 51 39 2.5 5.83 18.6 10 21 .31BS37 29A 1.3 <5 17 60 .7 <5 <1 .19 152 8 23.2 1.7 15.5 32 14 .24

64 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Table 15. Results of all elemental analyses performed by SGS Canada, Inc., Mineral Services, Toronto, Ontario, Canada, of sediment samples from six impoundments in the 

Assabet River Basin, Massachusetts, 2003.—Continued[Quantity in brackets is detection limit. Map ID: The identifier associated with a sampling site on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a replicate sample; DUP, SGS laboratory duplicate quality-control sample. %, percent; ppm, parts per million; <, actual value is less than value shown; --, not reported]

Map ID Sample ID

Aluminum

(%)

[0.01]

Antimony

(ppm) 

[5]

Arsenic

(ppm) 

[3]

Barium

(ppm) 

[1]

Beryllium

(ppm) 

[0.5]

Bismuth

(ppm) 

[5]

Cadmium

(ppm) 

[1]

Calcium

(%)

[0.01]

Chromium

(ppm) 

[1]

Cobalt

(ppm) 

[1]

Copper

(ppm) 

[0.5]

Iron

(%)

[0.01]

Lanthanum

(ppm) 

[0.5]

Lead

(ppm) 

[2]

Lithium

(ppm) 

[1]

Magnesium

(%)

[0.01]

Ben Smith—Continued

BS37 29B 1.41 <5 8 33 0.7 <5 <1 0.1 99 5 2.2 1.47 20.2 10 16 0.25BS37 29C 1.42 <5 4 39 .5 <5 <1 .09 130 4 1.7 1.59 27.1 11 21 .3BS38 26A 1.25 44 71 144 .8 <5 4 .36 160 29 131 2.25 13.7 3,800 11 .23BS38 26B 1.3 <5 59 111 .8 <5 2 .26 245 24 122 2.15 13.9 160 11 .21BS38 26C 1.43 <5 19 68 .8 <5 <1 .15 167 16 67.8 1.82 18.6 80 12 .22BS38 26D 1.46 <5 11 24 2.4 <5 <1 .12 147 6 5.8 1.87 60 13 9 .14BS38 26E 2.03 <5 9 37 1.3 <5 <1 .06 75 13 5.1 2.15 41.1 10 24 .45BS39 25A 1.29 <5 17 54 .6 <5 <1 .39 184 12 13.6 1.59 14 25 16 .32BS39 25B 1.26 <5 11 38 .5 <5 <1 .23 246 7 11.1 1.62 13.9 11 17 .33BS40 24A 1.32 <5 14 51 .6 <5 <1 .18 216 12 13.4 1.84 15.7 16 17 .33BS40 24B 1.17 <5 8 26 .6 <5 <1 .11 130 13 3.5 1.71 17.4 8 16 .31BS40 24C 1.51 <5 14 29 .9 <5 <1 .12 151 22 4.6 3.17 23.3 9 21 .37BS41 28A 1.55 <5 14 34 .9 <5 <1 .14 237 17 4.5 2.68 22.7 8 16 .3BS41 28AQ 1.5 <5 17 29 1 <5 <1 .12 106 18 3 2.58 20.5 9 16 .29BS41 28B 1.92 <5 83 41 1.5 11 <1 .11 91 29 2.7 6.94 18.2 14 18 .28BS41 28BQ 1.85 <5 73 39 1.4 <5 <1 .11 76 31 2.7 6.64 17 14 19 .29BS42 33A 1.05 <5 12 47 <.5 <5 <1 .27 239 9 38.6 1.25 10.5 50 11 .24BS42 33B 1.4 <5 10 43 .6 <5 <1 .36 383 5 41.2 1.46 14.2 29 14 .29BS43 30A 1.34 <5 21 278 .9 <5 5 .47 132 37 167 2.52 15 160 14 .31BS43 30B 1.34 <5 41 169 .8 <5 4 .38 182 29 117 2.21 15.1 157 13 .28BS43 30B-DUP 1.3 <5 37 169 .8 <5 4 .38 178 27 117 2.16 14.6 159 13 .27BS43 30C 1.42 <5 36 108 .7 <5 <1 .3 167 24 94.2 1.91 14.9 125 14 .27BS43 30D 1.37 <5 19 62 .6 <5 <1 .21 140 13 21.4 1.62 15.8 32 14 .25BS43 30E 1.15 <5 8 38 .7 <5 <1 .14 94 5 2.8 1.14 19.6 11 11 .16BS44 31A .51 <5 6 32 <.5 <5 <1 .13 254 3 5.5 1.06 8 5 9 .18BS44 31B .51 <5 5 23 .5 <5 <1 .09 271 3 11.7 .78 12.1 18 6 .12BS45 32A .56 <5 <3 32 <.5 <5 <1 .07 180 2 3.8 .93 7.8 3 12 .22BS45 32B .77 <5 4 33 <.5 <5 <1 .11 228 3 1.3 1.09 16.2 8 12 .23

Tables 14–17 65
Table 15. Results of all elemental analyses performed by SGS Canada, Inc., Mineral Services, Toronto, Ontario, Canada, of sediment samples from six impoundments in the 

Assabet River Basin, Massachusetts, 2003.—Continued[Quantity in brackets is detection limit. Map ID: The identifier associated with a sampling site on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a replicate sample; DUP, SGS laboratory duplicate quality-control sample. %, percent; ppm, parts per million; <, actual value is less than value shown; --, not reported]

Map ID Sample ID

Aluminum

(%)

[0.01]

Antimony

(ppm) 

[5]

Arsenic

(ppm) 

[3]

Barium

(ppm) 

[1]

Beryllium

(ppm) 

[0.5]

Bismuth

(ppm) 

[5]

Cadmium

(ppm) 

[1]

Calcium

(%)

[0.01]

Chromium

(ppm) 

[1]

Cobalt

(ppm) 

[1]

Copper

(ppm) 

[0.5]

Iron

(%)

[0.01]

Lanthanum

(ppm) 

[0.5]

Lead

(ppm) 

[2]

Lithium

(ppm) 

[1]

Magnesium

(%)

[0.01]

Powdermill

P46 48 1.06 7 21 94 <0.5 <5 2 0.3 899 13 280 1.86 10.6 233 13 0.32P46 48Q 1.03 8 19 90 <.5 <5 2 .28 942 13 274 1.84 10 226 13 .32P47 49 .81 <5 8 78 <.5 <5 <1 .27 394 10 50.9 1.62 9.8 110 11 .25P48 46A 1.58 10 34 85 <.5 <5 1 .2 1,290 12 257 1.65 10.7 259 13 .3P48 46A-DUP 1.56 15 40 86 .5 <5 <1 .2 1,260 11 254 1.61 10.8 254 12 .3P48 46B 1.52 <5 20 49 <.5 <5 <1 .13 238 27 31.6 2.41 14.4 23 16 .37P48 46C 2.26 <5 62 69 .8 <5 <1 .06 129 60 17.2 4.4 20.2 11 20 .34P49 47 .76 <5 5 46 <.5 <5 <1 .16 268 6 19.4 1.79 9.4 58 13 .32P50 52A 1.04 5 15 180 .7 <5 2 .43 272 23 109 2.76 10.7 231 15 .35P50 52B 1.09 <5 13 181 .5 <5 2 .28 339 20 123 2.75 11.3 261 15 .37P50 52C .7 <5 11 133 <.5 <5 1 .18 311 15 78.3 2.28 7.8 244 10 .25P50 52CQ .7 <5 9 126 <.5 <5 1 .17 242 15 90.3 2.51 7.2 239 10 .25P50 52D 1.09 <5 22 107 <.5 <5 4 .28 478 12 128 2.22 11.9 174 12 .33P50 52E .92 <5 36 99 <.5 <5 <1 .23 291 9 55 1.62 9.2 318 11 .25P50 52E-DUP .9 <5 35 96 <.5 <5 <1 .22 288 8 54.3 1.56 10.1 326 11 .24P51 55A 1.27 7 31 139 .7 <5 5 .6 1,060 23 839 1.77 10.8 594 10 .26P51 55AQ 1.23 10 29 144 .7 <5 5 .61 1,020 22 886 1.84 11.2 626 10 .29P51 55B 1.98 15 58 69 .6 <5 3 .8 1,830 11 386 1.33 10.5 343 9 .26P51 55B-DUP 1.98 15 58 69 .6 <5 3 .8 1,810 9 385 1.33 11.7 346 9 .27P51 55C .8 <5 <3 83 .8 <5 <1 2.07 97 6 22.4 .66 21.7 12 2 .18P51 55D 1.13 <5 6 64 .9 <5 <1 .67 128 7 40 .69 50.5 7 16 .22P52 53A 1.05 <5 16 193 .6 <5 2 .47 399 25 100 3.07 11.1 167 15 .35P52 53B 1.06 <5 13 214 <.5 <5 4 .3 404 21 184 2.22 12.9 371 13 .34P52 53C 1.8 17 101 134 <.5 <5 7 .35 2,270 7 330 2.27 9.2 621 12 .35P52 53D 1.32 <5 20 104 <.5 <5 <1 .26 421 8 194 1.92 11.7 115 11 .37P52 53DQ 1.29 <5 15 101 <.5 <5 <1 .25 427 8 185 1.88 11.7 109 11 .36P52 53E 1.07 <5 10 57 <.5 <5 <1 .17 302 16 26.8 1.65 11.1 71 13 .3P53 56A 1.57 <5 18 310 1.3 <5 6 .32 416 50 669 2.45 17.7 580 17 .42P53 56B 1.73 11 47 226 .7 <5 4 .21 1,550 20 277 2.05 15.1 515 15 .34P53 56BQ 1.79 12 52 216 .7 <5 4 .21 1,590 18 275 2.01 14.5 511 15 .34

66 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Table 15. Results of all elemental analyses performed by SGS Canada, Inc., Mineral Services, Toronto, Ontario, Canada, of sediment samples from six impoundments in the 

Assabet River Basin, Massachusetts, 2003.—Continued[Quantity in brackets is detection limit. Map ID: The identifier associated with a sampling site on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a replicate sample; DUP, SGS laboratory duplicate quality-control sample. %, percent; ppm, parts per million; <, actual value is less than value shown; --, not reported]

Map ID Sample ID

Aluminum

(%)

[0.01]

Antimony

(ppm) 

[5]

Arsenic

(ppm) 

[3]

Barium

(ppm) 

[1]

Beryllium

(ppm) 

[0.5]

Bismuth

(ppm) 

[5]

Cadmium

(ppm) 

[1]

Calcium

(%)

[0.01]

Chromium

(ppm) 

[1]

Cobalt

(ppm) 

[1]

Copper

(ppm) 

[0.5]

Iron

(%)

[0.01]

Lanthanum

(ppm) 

[0.5]

Lead

(ppm) 

[2]

Lithium

(ppm) 

[1]

Magnesium

(%)

[0.01]

Powdermill—Continued

P53 56C 1.82 19 66 109 0.9 7 8 0.26 1,970 12 545 1.8 10.5 419 11 0.33P54 54A 1.61 5 44 456 .7 -- 7 .53 1,530 19 3430 2.1 12.9 1,030 13 .33P54 54B .6 <5 6 97 .7 <5 <1 1.45 148 7 49.8 1.08 11.6 29 1 .12P54 54C .89 <5 <3 65 1.6 <5 <1 1.46 106 2 14.6 .78 30.7 14 3 .11P54 54CQ .77 <5 <3 56 1.1 <5 <1 1.18 135 2 11.7 .71 24.1 13 4 .1P55 51A 1.15 <5 9 77 <.5 <5 <1 .32 248 17 78 1.96 14.4 54 14 .32P55 51B 1.26 <5 6 31 <.5 <5 <1 .2 179 17 10.5 1.72 18.6 11 15 .31P55 51BQ 1.28 <5 6 33 <.5 <5 <1 .2 134 20 10.8 1.82 20.6 10 15 .32P55 51C 1.32 <5 9 22 .5 <5 <1 .14 173 21 6.2 2.06 19 7 16 .33P55 51D 1.23 <5 6 22 .5 <5 <1 .11 274 10 5.5 2.06 21.5 7 16 .34P55 51E 1.27 <5 4 29 1 <5 <1 .11 240 8 5.9 1.54 20.6 7 18 .31P56 50A 1.79 <5 17 323 1 <5 6 .59 332 88 720 3.09 18 411 22 .47P56 50AQ 1.73 <5 17 312 1 <5 6 .59 291 83 675 3 17.4 393 21 .46P56 50B 2.03 7 28 589 1.4 <5 10 .53 786 57 910 2.9 21 1,250 19 .44P56 50C 1.81 11 48 136 .6 <5 9 .36 1,320 12 459 2.16 13 305 15 .44P56 50D 1.39 <5 9 73 <.5 <5 <1 .33 187 15 23.7 1.61 14.4 40 16 .32P56 50E .65 <5 <3 49 .7 <5 <1 .26 221 3 9.1 .54 25.5 7 4 .07P56 50E-DUP .65 <5 <3 48 .7 <5 <1 .26 235 3 8.9 .54 26.4 9 5 .07P57 57 1.18 <5 <3 54 <.5 <5 <1 .2 272 7 18 2 16.8 45 25 .53P57 57Q 1.28 <5 4 48 <.5 <5 <1 .16 209 6 16.2 2.03 15.6 15 27 .73

Tables 14–17 67
Table 15. Results of all elemental analyses performed by SGS Canada, Inc., Mineral Services, Toronto, Ontario, Canada, of sediment samples from six impoundments in the 

Assabet River Basin, Massachusetts, 2003.—Continued[Quantity in brackets is detection limit. Map ID: The identifier associated with a sampling site on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a replicate sample; DUP, SGS laboratory duplicate quality-control sample. %, percent; ppm, parts per million; <, actual value is less than value shown; --, not reported]

MapID Sample ID

Manganese

(ppm) 

[2]

Molybdenum

(ppm) 

[1]

Nickel

(ppm) 

[1]

Phosphorus

(%)

[0.01]

Potassium

(%)

[0.01]

Scandium

(ppm) 

[0.5]

Silver

(ppm) 

[0.2]

Sodium

(%)

[0.01]

Strontium

(ppm) 

[0.5]

Tin

(ppm) 

[10]

Titanium

(%)

[0.01]

Tungsten

(ppm) 

[10]

Vanadium 

(ppm) 

[2]

Yttrium 

(ppm) 

[0.5]

Zinc

(ppm) 

[0.5]

Zirconium

(ppm) 

[0.5]

Aluminum City

AC1 5 481 5 22 0.16 0.25 1.9 4.9 0.04 27.7 13 0.05 <10 27 7.3 183 2.8AC2 7A 605 8 22 .23 .14 1.6 5.2 .05 49.1 <10 .03 <10 26 9.2 249 3.2AC2 7B 617 5 28 .28 .19 1.8 >10 .04 49.5 34 .03 <10 26 9.4 397 3.2AC2 7C 633 1 18 .22 .11 1.7 1.4 .1 39.3 14 .03 <10 20 6.6 155 1.3AC3 6A 266 7 22 .13 .14 1.5 5.6 .03 45.6 14 .03 <10 26 8.5 278 3.1AC3 6B 235 5 30 .19 .2 1.5 >10 .03 53.2 30 .03 <10 29 10.6 495 3.5AC3 6C 380 5 24 .17 .21 2.1 2.5 .03 50.9 26 .04 <10 30 9.5 296 2.8AC4 8A 481 6 24 .17 .14 1.6 5.4 .05 39.8 <10 .03 <10 23 9 223 2.8AC4 8B 557 7 24 .17 .15 1.3 9.8 .05 33.9 12 .03 <10 22 8.5 291 2.7AC4 8B-DUP 557 6 23 .17 .15 1.4 9.5 .05 33.8 13 .03 <10 22 8.4 280 2.8AC4 8C 392 6 31 .12 .17 1.6 2.1 .04 25.6 40 .04 <10 16 6.1 1,220 2.5

Allen Street

AS5 1A 169 3 17 0.05 0.18 1.7 0.2 0.04 21.1 24 0.05 <10 22 4.8 211 2AS5 1A-DUP 170 3 16 .05 .18 1.6 .2 .04 20.6 23 .05 <10 21 4.9 199 1.8AS5 1B 135 <1 14 .05 .13 1.3 .3 .04 27 47 .05 <10 21 4.8 184 1.5AS5 1C 193 3 16 .06 .17 1.8 .3 .03 22.3 45 .06 <10 25 5.6 136 1.9AS5 1D 146 <1 16 .05 .17 1.8 <.2 .03 22.7 19 .06 <10 23 4.4 83.4 1.7AS6 3A 395 4 33 .21 .22 2 4.8 .05 46.7 33 .04 <10 29 10.4 487 3.2AS6 3B 294 4 19 .08 .16 1.8 .4 .05 25.1 30 .05 <10 24 6.3 182 2AS6 3C 323 2 17 .18 .13 1.3 <.2 .03 18 <10 .05 <10 26 4.2 78.3 1AS7 2A 600 5 30 .21 .19 2.3 .7 .04 32.3 25 .06 <10 32 8.3 827 3.2AS7 2B 213 <1 18 .07 .15 1.8 .4 .03 20.4 53 .05 <10 24 5.9 474 2.1AS7 2C 222 3 17 .08 .16 1.8 .4 .03 23.8 33 .05 <10 26 6.6 351 2AS7 2D 202 <1 19 .07 .18 2.1 <.2 .02 19.6 11 .06 <10 27 6.2 87.3 1.9AS8 4A 844 9 24 .19 .16 1.6 2.9 .05 42.5 12 .03 <10 24 8 281 3.4AS8 4B 669 3 31 .28 .19 1.4 >10 .05 55.2 30 .03 <10 26 9.8 551 4.1AS8 4B-DUP 669 4 35 .31 .2 1.6 >10 .06 59.3 28 .03 <10 27 10.3 604 4.2AS8 4C 737 2 27 .31 .17 1.9 2.3 .04 44.1 27 .04 <10 25 8.7 515 2.4AS8 4D 320 <1 23 .11 .22 2.6 .3 .03 21 19 .07 <10 34 8.1 221 2.2AS8 4E 266 2 15 .06 .12 1.4 <.2 .04 21.9 <10 .05 <10 23 5.9 54 1.4

68 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Table 15. Results of all elemental analyses performed by SGS Canada, Inc., Mineral Services, Toronto, Ontario, Canada, of sediment samples from six impoundments in the 

Assabet River Basin, Massachusetts, 2003.—Continued[Quantity in brackets is detection limit. Map ID: The identifier associated with a sampling site on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a replicate sample; DUP, SGS laboratory duplicate quality-control sample. %, percent; ppm, parts per million; <, actual value is less than value shown; --, not reported]

MapID Sample ID

Manganese

(ppm) 

[2]

Molybdenum

(ppm) 

[1]

Nickel

(ppm) 

[1]

Phosphorus

(%)

[0.01]

Potassium

(%)

[0.01]

Scandium

(ppm) 

[0.5]

Silver

(ppm) 

[0.2]

Sodium

(%)

[0.01]

Strontium

(ppm) 

[0.5]

Tin

(ppm) 

[10]

Titanium

(%)

[0.01]

Tungsten

(ppm) 

[10]

Vanadium 

(ppm) 

[2]

Yttrium 

(ppm) 

[0.5]

Zinc

(ppm) 

[0.5]

Zirconium

(ppm) 

[0.5]

Hudson

H9 9 98 <1 14 0.06 0.04 0.9 <0.2 0.03 24.3 <10 <0.01 <10 13 10.6 35 <0.5H10 12A 243 2 41 .13 .17 2.2 .9 .04 26.9 <10 .05 <10 36 8.5 212 2.2H10 12B 232 <1 24 .11 .2 2.3 .3 .03 23.3 <10 .05 <10 31 8 300 2.1H10 12C 258 <1 22 .1 .31 2.8 <.2 .03 15.5 <10 .08 <10 37 8.7 122 2.7H10 12D 167 <1 8 .04 .03 <.5 <.2 .03 24 <10 .01 <10 11 7.4 14.6 <.5H10 12E 89 <1 12 .05 .08 2.3 <.2 .02 17.6 <10 .02 <10 13 78.8 16 <.5H11 13A 733 2 38 .09 .11 1.5 .4 .03 23.1 <10 .03 <10 24 8.9 288 1.5H11 13A-DUP 745 2 38 .09 .11 1.6 .5 .03 25.2 <10 .03 <10 22 9.1 263 1.7H11 13B 1,100 <1 14 .04 .05 1.2 <.2 .02 17.5 <10 .03 <10 25 13.7 19.4 <.5H11 13C 1,590 2 22 .05 .04 2.8 <.2 .02 15.7 <10 .05 <10 49 36.5 38.7 1.6H11 13D 949 2 33 .02 .08 4.2 <.2 .03 8.9 <10 .1 <10 53 21.6 62.7 4.1H12 11A 237 2 20 .04 .05 1 <.2 .02 10.8 <10 .03 <10 17 4.7 28.1 <.5H12 11B 148 1 14 .01 .06 1.2 <.2 .03 7.4 <10 .04 <10 18 4.3 18.9 .9H13 14A 146 7 57 .11 .16 2.1 1.2 .06 52.2 34 .03 <10 26 7.9 410 3.8H13 14A-DUP 146 7 52 .11 .17 2 .8 .07 54.3 31 .04 <10 27 8.1 380 2.8H13 14AQ 148 7 62 .11 .17 1.9 .4 .07 54.6 38 .03 <10 26 8 418 1.3H13 14B 139 5 36 .09 .2 2.5 <.2 .05 51.5 26 .05 <10 30 7.1 422 2.6H13 14BQ 139 5 38 .08 .21 2.5 .7 .05 49 29 .05 <10 31 7 389 2.7H13 14C 141 7 29 .04 .25 1.7 <.2 .04 22.4 74 .04 <10 21 3.5 66.1 1.9H13 14CQ 154 7 29 .04 .25 1.9 <.2 .04 20.5 145 .05 <10 22 3.6 69 1.7H13 14D 49 5 14 .18 .04 .9 <.2 .04 55.5 <10 .02 <10 12 2.7 12.7 .9H13 14DQ 48 8 17 .04 .05 .9 <.2 .05 64.2 <10 .02 <10 14 3.1 12.4 .6H13 14E 87 1 11 .06 .09 1.6 <.2 .03 17.6 <10 .03 <10 10 4.3 16.2 <.5H13 14EQ 97 6 19 .04 .09 1.6 <.2 .03 16.7 <10 .03 <10 11 4.3 16.4 <.5H14 10A 776 3 32 .14 .08 1 .6 .03 22.6 <10 .02 <10 17 6.1 77 1H14 10B 287 <1 12 .04 .04 .9 <.2 .03 9.1 <10 .02 <10 15 8.7 20.7 <.5H15 15A 869 4 86 .32 .23 2.7 1.5 .07 39.9 14 .04 <10 35 9.8 406 1.9H15 15B 460 3 29 .16 .22 2.9 .8 .06 33.8 13 .05 <10 33 8.9 365 2.3H15 15C 364 5 22 .09 .11 2.2 .3 .06 25.7 <10 .03 <10 34 6.6 69 <.5H15 15C-DUP 352 5 21 .08 .11 2.1 <.2 .06 25.2 <10 .04 <10 33 6.6 64.3 1.4H15 15D 318 12 11 .06 .05 2.8 .3 .03 12 <10 .04 <10 87 6.6 21.8 3.2

Tables 14–17 69
Table 15. Results of all elemental analyses performed by SGS Canada, Inc., Mineral Services, Toronto, Ontario, Canada, of sediment samples from six impoundments in the 

Assabet River Basin, Massachusetts, 2003.—Continued[Quantity in brackets is detection limit. Map ID: The identifier associated with a sampling site on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a replicate sample; DUP, SGS laboratory duplicate quality-control sample. %, percent; ppm, parts per million; <, actual value is less than value shown; --, not reported]

MapID Sample ID

Manganese

(ppm) 

[2]

Molybdenum

(ppm) 

[1]

Nickel

(ppm) 

[1]

Phosphorus

(%)

[0.01]

Potassium

(%)

[0.01]

Scandium

(ppm) 

[0.5]

Silver

(ppm) 

[0.2]

Sodium

(%)

[0.01]

Strontium

(ppm) 

[0.5]

Tin

(ppm) 

[10]

Titanium

(%)

[0.01]

Tungsten

(ppm) 

[10]

Vanadium 

(ppm) 

[2]

Yttrium 

(ppm) 

[0.5]

Zinc

(ppm) 

[0.5]

Zirconium

(ppm) 

[0.5]

Gleasondale

G16 34A 119 2 12 0.08 0.05 1 0.3 0.03 31.8 <10 0.01 <10 17 6.5 18.6 0.6G16 34B 115 3 16 .06 .07 1.7 .4 .03 22.6 <10 .02 <10 23 8.4 32.1 .8G16 34C 111 1 17 .04 .06 2.2 <.2 .02 14.8 <10 .03 <10 20 8.3 27.6 .7G16 34C-DUP 107 1 16 .04 .05 2 <.2 .02 14.3 <10 .03 <10 20 8.1 26.9 .7G17 39A 188 3 16 .04 .25 1.6 <.2 .03 6.2 <10 .03 <10 16 3.6 29.2 3.1G17 39B 132 <1 15 .03 .26 1.5 <.2 .04 7.6 <10 .04 <10 15 3.2 22.3 2.9G17 39C 161 3 16 .04 .26 1.8 <.2 .05 10.1 <10 .05 <10 18 4.3 28.5 3.9G17 39D 163 1 17 .03 .27 1.5 <.2 .05 7.1 <10 .04 <10 15 3.5 24.3 3.4G18 35A 492 10 33 .17 .2 2.3 1.5 .05 27.7 20 .04 14 29 8 369 2.9G18 35B 330 3 23 .14 .18 2.3 1.6 .03 24 23 .04 <10 28 8.8 484 2.4G18 35C 263 4 22 .12 .22 2.4 .8 .03 22.8 19 .04 <10 29 8.9 315 2.8G18 35D 272 1 18 .09 .21 2.3 .6 .02 21.3 15 .05 <10 26 7.6 262 4.3G18 35E 407 5 22 .07 .22 2.4 .9 .04 17.5 <10 .05 <10 26 8.2 180 2.6G19 40A 1,420 11 91 .67 .2 2.1 2.5 .06 57.7 27 .03 14 34 12.1 464 2.5G19 40B 516 7 26 .19 .24 2.7 .9 .05 37 21 .03 13 31 8.1 518 2.3G19 40B-DUP 511 7 26 .19 .23 2.6 .9 .05 36.5 20 .03 12 30 8 506 2.9G19 40C 453 3 24 .17 .24 2.6 .3 .04 32.3 15 .04 <10 29 9 358 3.4G19 40CQ 436 3 26 .15 .25 2.7 .3 .04 31.4 15 .04 <10 30 9 346 3.4G19 40D 245 2 19 .07 .18 1.8 <.2 .03 14.1 <10 .04 <10 18 4.8 101 1.9G19 40E 127 3 12 .02 .15 1 <.2 .03 5.3 <10 .02 <10 10 2.8 19.6 2.2G20 36A 262 2 15 .06 .09 1.3 <.2 .06 21.7 <10 .02 <10 15 4.8 31.4 1.1G20 36AQ 326 9 22 .06 .15 1.6 <.2 .08 21.5 <10 .02 <10 17 6 29.7 1.7G20 36B 310 2 14 .06 .05 1.3 .2 .06 19.1 <10 .02 <10 18 5.7 24.2 .8G20 36C 294 3 15 .04 .05 1.7 <.2 .04 17.1 <10 .03 <10 18 6.2 38.7 .8G20 36D 375 3 18 .04 .04 1.5 <.2 .03 21.3 <10 .03 <10 15 7.5 31.2 1.5G20 36E 727 7 28 .05 .02 1.7 <.2 .03 41.5 <10 .02 <10 13 14.2 93.8 2.9G21 44 206 4 22 .07 .16 1 <.2 .05 16 97 .02 <10 12 3 71 2.2G22 41A 1,600 8 149 .71 .22 2.1 4.5 .07 52 21 .03 <10 32 10.5 485 3.2G22 41B 488 5 44 .19 .17 1.7 .9 .05 25.6 16 .03 <10 22 5.6 248 2.1G22 41C 368 6 22 .1 .23 1.9 <.2 .05 22.6 <10 .04 <10 23 5.8 142 2.3

70 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Table 15. Results of all elemental analyses performed by SGS Canada, Inc., Mineral Services, Toronto, Ontario, Canada, of sediment samples from six impoundments in the 

Assabet River Basin, Massachusetts, 2003.—Continued[Quantity in brackets is detection limit. Map ID: The identifier associated with a sampling site on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a replicate sample; DUP, SGS laboratory duplicate quality-control sample. %, percent; ppm, parts per million; <, actual value is less than value shown; --, not reported]

MapID Sample ID

Manganese

(ppm) 

[2]

Molybdenum

(ppm) 

[1]

Nickel

(ppm) 

[1]

Phosphorus

(%)

[0.01]

Potassium

(%)

[0.01]

Scandium

(ppm) 

[0.5]

Silver

(ppm) 

[0.2]

Sodium

(%)

[0.01]

Strontium

(ppm) 

[0.5]

Tin

(ppm) 

[10]

Titanium

(%)

[0.01]

Tungsten

(ppm) 

[10]

Vanadium 

(ppm) 

[2]

Yttrium 

(ppm) 

[0.5]

Zinc

(ppm) 

[0.5]

Zirconium

(ppm) 

[0.5]

Gleasondale—Continued

G23 37A 123 2 15 0.04 0.14 0.9 <0.2 0.04 7.4 <10 0.02 <10 9 2.3 31.7 1.8G23 37A-DUP 125 1 16 .04 .14 .9 <.2 .04 7.5 <10 .02 <10 9 2.3 32.1 2.4G23 37B 130 4 13 .03 .16 1 <.2 .04 6.4 <10 .02 <10 10 2.4 36.8 2.4G23 37C 134 2 13 .03 .12 .9 <.2 .03 9.7 <10 .02 <10 9 2.6 47.6 1.6G23 37D 301 4 23 .09 .24 2.3 .4 .05 22.5 12 .04 <10 24 7.5 191 3.5G24 42A 190 5 17 .05 .06 2.9 <.2 .02 9 <10 .03 <10 39 10.5 33.7 .5G24 42B 110 3 17 .02 .09 2.8 <.2 .03 6.9 <10 .03 <10 29 9.3 25.3 2.5G25 45 164 4 11 .02 .13 1 <.2 .03 5.6 <10 .02 <10 10 2.7 23.7 2.5G25 45-DUP 159 3 11 .02 .13 .9 <.2 .03 5.5 <10 .02 <10 9 2.6 23.3 2.1G26 38A 67 3 9 .07 .05 .9 <.2 .03 55.2 <10 .01 <10 17 6 15 .6G26 38B 60 4 9 .06 .04 .8 <.2 .03 45.9 <10 .01 <10 11 3.9 15.9 .7G26 38C 102 5 24 .04 .07 1.4 <.2 .03 32 <10 .02 <10 19 5.4 34.2 .6G27 43 299 6 24 .08 .14 1.1 <.2 .04 14 <10 .02 <10 13 2.9 84.2 2.5

Ben Smith

BS28 16A 190 4 20 0.06 0.09 1.1 0.3 0.03 9.3 <10 .02 <10 11 3.3 82.8 0.8BS28 16B 161 2 15 .04 .16 1.2 <.2 .03 5.7 13 .02 <10 13 2.9 50.1 1.6BS29 18A 137 3 14 .15 .04 .8 <.2 .04 49.2 <10 <.01 <10 8 31.2 43.9 .8BS29 18B 92 1 9 .14 .04 .9 <.2 .04 40.6 <10 <.01 <10 6 37.5 5.7 1.5BS29 18C 70 4 16 .06 .06 1.9 <.2 .02 13.3 <10 <.01 <10 10 58.8 9.8 .7BS29 19A 750 5 32 .2 .16 2.1 1.3 .05 33.7 53 .03 <10 29 10.2 479 2BS30 17A 679 7 98 .24 .15 2.2 2.6 .07 39.3 40 .03 <10 27 10.1 515 2.5BS30 17B 521 3 31 .16 .16 2.3 1.3 .07 34.6 42 .02 <10 26 8.9 617 2.5BS30 17C 491 5 31 .16 .17 2.1 .9 .06 32.2 68 .03 <10 27 10 637 2.3BS30 17D 399 3 23 .13 .11 1.6 <.2 .05 28.1 160 .02 <10 21 8.9 165 .5BS30 17E 118 1 8 .11 .03 .8 .3 .02 22 <10 <.01 <10 9 14.7 3.2 .8BS31 19A-DUP 730 4 30 .19 .16 2.1 .2 .05 33 46 .03 <10 28 9.9 454 2.1BS31 19AQ 734 5 34 .2 .16 2.1 .8 .05 32.9 51 .02 <10 28 9.9 481 1.9BS31 19B 761 3 29 .17 .17 2.2 .8 .04 28.2 111 .03 <10 28 9.5 281 1.9BS31 19BQ 762 5 32 .17 .16 2.2 .8 .04 27.8 113 .03 <10 28 9.4 277 2

Tables 14–17 71
Table 15. Results of all elemental analyses performed by SGS Canada, Inc., Mineral Services, Toronto, Ontario, Canada, of sediment samples from six impoundments in the 

Assabet River Basin, Massachusetts, 2003.—Continued[Quantity in brackets is detection limit. Map ID: The identifier associated with a sampling site on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a replicate sample; DUP, SGS laboratory duplicate quality-control sample. %, percent; ppm, parts per million; <, actual value is less than value shown; --, not reported]

MapID Sample ID

Manganese

(ppm) 

[2]

Molybdenum

(ppm) 

[1]

Nickel

(ppm) 

[1]

Phosphorus

(%)

[0.01]

Potassium

(%)

[0.01]

Scandium

(ppm) 

[0.5]

Silver

(ppm) 

[0.2]

Sodium

(%)

[0.01]

Strontium

(ppm) 

[0.5]

Tin

(ppm) 

[10]

Titanium

(%)

[0.01]

Tungsten

(ppm) 

[10]

Vanadium 

(ppm) 

[2]

Yttrium 

(ppm) 

[0.5]

Zinc

(ppm) 

[0.5]

Zirconium

(ppm) 

[0.5]

Ben Smith—Continued

BS31 19C 537 3 23 0.12 0.11 1.8 0.2 0.04 20.2 215 0.02 <10 24 8.1 112 0.6BS31 19CQ 533 5 25 .12 .1 1.8 <.2 .04 20.4 217 .02 <10 24 8.2 104 <.5BS31 19D 284 6 20 .08 .06 1.6 <.2 .03 11.3 <10 .02 <10 22 7.2 21.6 1.2BS31 19DQ 281 2 16 .08 .06 1.6 <.2 .02 10.8 <10 .02 <10 21 6.5 21.6 .5BS31 19E 254 5 22 .06 .05 1.5 <.2 .02 12.8 <10 .02 <10 17 6.6 16.8 .8BS31 19EQ 270 3 18 .05 .06 1.7 <.2 .02 13.6 <10 .02 <10 21 6.8 19.3 1BS32 20A 3,040 9 132 .86 .17 2 5 .08 51.2 30 .02 <10 26 10.9 492 2.1BS32 20B 1,020 3 36 .29 .14 2 1.9 .06 44.3 38 .03 <10 28 9.2 481 1.9BS32 20C 578 4 16 .08 .04 1.1 <.2 .04 36.7 <10 .01 <10 13 6.4 34.4 .8BS32 20C-DUP 553 3 15 .08 .04 .9 <.2 .04 35.4 <10 .02 <10 12 6.2 32 .7BS32 20D 596 3 12 .06 .03 1.1 <.2 .04 31.1 <10 .01 <10 13 7.6 23 1.3BS32 20E 527 4 19 .06 .04 1.2 <.2 .03 25 <10 .02 <10 14 6.7 29.8 1.3BS33 21A 541 3 26 .18 .15 2.2 .9 .06 33.7 126 .02 <10 25 9.4 334 1.2BS33 21B 401 3 16 .09 .05 1.5 <.2 .04 21.6 15 .02 <10 24 7.7 30.9 <.5BS33 21C 397 1 14 .07 .04 1.4 <.2 .03 19.7 <10 .02 <10 19 7.1 21.6 <.5BS33 21D 439 4 17 .06 .04 1.6 <.2 .03 22.4 <10 .02 <10 17 7 25.1 .5BS33 21E 450 2 16 .05 .07 1.8 .3 .02 21.1 <10 .03 <10 17 6.6 26.6 .9BS34 22A 470 7 59 .18 .14 1.8 1.9 .04 30.1 30 .02 <10 27 11.1 484 1BS34 22B 234 2 15 .04 .07 1.4 <.2 .03 11.7 10 .02 <10 15 5.8 38.3 1.3BS34 22C 186 3 14 .03 .11 1.3 <.2 .02 5.3 <10 .03 <10 13 5.4 19.4 1BS35 23A 441 4 47 .17 .12 1.7 1.4 .03 29.5 23 .02 <10 26 9.1 446 2BS35 23B 280 5 27 .13 .11 1.7 .8 .03 27.2 39 .02 <10 26 9.3 458 1.8BS35 23B-DUP 277 5 25 .12 .11 1.5 <.2 .02 27.2 34 .02 <10 25 9.2 445 1.3BS35 23C 162 3 15 .06 .05 1.3 <.2 .03 23.4 <10 .02 <10 16 12.6 37.5 <.5BS36 27A 423 3 14 .07 .05 2.2 .3 .04 14 <10 .03 <10 29 10.3 26.4 <.5BS36 27B 477 6 18 .05 .09 3.3 <.2 .05 11.9 <10 .05 <10 41 15.4 27.8 1.3BS36 27C 1,170 7 18 .03 .05 3.6 .2 .04 9.7 <10 .05 <10 56 16.6 26.8 2.8BS36 27D 1,250 9 14 .02 .03 2.5 .5 .02 8.8 <10 .05 <10 49 11.8 24.2 3.1BS36 27D-DUP 1,240 9 14 .02 .03 2.5 <.2 .02 8.7 <10 .05 <10 48 11.6 23.7 3.5BS37 29A 232 4 16 .09 .08 1.7 <.2 .04 15.7 <10 .02 <10 21 8.5 62.2 .9

72 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Table 15. Results of all elemental analyses performed by SGS Canada, Inc., Mineral Services, Toronto, Ontario, Canada, of sediment samples from six impoundments in the 

Assabet River Basin, Massachusetts, 2003.—Continued[Quantity in brackets is detection limit. Map ID: The identifier associated with a sampling site on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a replicate sample; DUP, SGS laboratory duplicate quality-control sample. %, percent; ppm, parts per million; <, actual value is less than value shown; --, not reported]

MapID Sample ID

Manganese

(ppm) 

[2]

Molybdenum

(ppm) 

[1]

Nickel

(ppm) 

[1]

Phosphorus

(%)

[0.01]

Potassium

(%)

[0.01]

Scandium

(ppm) 

[0.5]

Silver

(ppm) 

[0.2]

Sodium

(%)

[0.01]

Strontium

(ppm) 

[0.5]

Tin

(ppm) 

[10]

Titanium

(%)

[0.01]

Tungsten

(ppm) 

[10]

Vanadium 

(ppm) 

[2]

Yttrium 

(ppm) 

[0.5]

Zinc

(ppm) 

[0.5]

Zirconium

(ppm) 

[0.5]

Ben Smith—Continued

BS37 29B 107 1 12 0.03 0.05 2.3 <0.2 0.02 9.2 <10 0.02 <10 24 10.1 18.4 0.6BS37 29C 95 2 13 <.01 .07 3.3 <.2 .03 9.3 <10 .03 <10 48 11 18.7 2.6BS38 26A 822 3 46 .14 .13 1.7 1.8 .05 29.6 28 .02 <10 27 9.2 483 1.6BS38 26B 1,060 4 28 .12 .12 1.6 .6 .03 22.7 53 .02 <10 26 9.4 390 1BS38 26C 1,130 3 22 .09 .07 1.8 .2 .03 12.4 73 .02 <10 24 10.6 110 1.3BS38 26D 1,550 4 23 .05 .03 1.6 <.2 .02 6.9 <10 .01 <10 23 41.2 13.7 .9BS38 26E 461 2 28 .02 .06 2.7 <.2 .02 3.9 <10 .07 <10 29 41.1 44.6 1.4BS39 25A 208 3 25 .07 .09 1.8 <.2 .04 23.3 <10 .04 <10 22 7.3 53.7 1BS39 25B 173 7 26 .06 .08 1.8 .3 .03 13.9 <10 .04 <10 21 6.1 29 1.4BS40 24A 469 7 27 .08 .07 2 <.2 .03 11.7 <10 .04 <10 23 7.1 36.9 1.5BS40 24B 377 2 17 .04 .03 2 .2 .02 7.4 <10 .03 <10 23 8.9 23.8 .7BS40 24C 1,090 6 25 .05 .04 2.8 <.2 .02 7.6 <10 .05 <10 32 13.3 27 1.3BS41 28A 589 6 18 .04 .09 3.1 .2 .06 13.9 <10 .05 <10 33 15.8 23.4 1.9BS41 28AQ 605 3 15 .04 .06 3 <.2 .04 12.4 <10 .04 <10 33 16 23 1.3BS41 28B 1,100 9 18 .04 .05 3.3 .3 .04 12.7 <10 .04 <10 66 13.6 22.3 3.6BS41 28BQ 1,180 8 17 .04 .04 3.1 .4 .03 12.3 <10 .04 <10 64 12.8 22.3 3.1BS42 33A 107 3 21 .06 .12 1.4 .2 .04 28.5 21 .04 <10 18 5.5 81.1 1.6BS42 33B 139 7 19 .07 .14 1.8 <.2 .05 35.2 42 .05 <10 24 7.2 43.4 1.6BS43 30A 1,220 5 68 .34 .18 2.1 2.4 .06 40.2 21 .03 <10 26 10.2 386 1.9BS43 30B 747 4 47 .2 .15 2 1.5 .04 30.8 24 .03 <10 27 9.4 422 1.8BS43 30B-DUP 747 4 46 .2 .15 1.9 .7 .04 30.5 22 .03 <10 26 9.4 421 1.6BS43 30C 505 2 22 .13 .13 1.9 .4 .03 22.8 82 .03 <10 26 8.6 213 1.2BS43 30D 303 4 17 .1 .08 1.7 <.2 .03 14.9 32 .02 <10 25 8.2 47 .7BS43 30E 173 2 11 .06 .04 1.7 <.2 .03 11 <10 <.01 <10 19 9.7 13.3 <.5BS44 31A 157 4 12 .02 .12 .9 <.2 .04 8.4 <10 .02 <10 9 2.8 16.6 1.3BS44 31B 88 5 11 .03 .11 1.2 .2 .04 9.5 <10 .02 <10 8 3.4 22.6 2.1BS45 32A 95 1 11 .02 .15 .8 <.2 .04 6.2 <10 .01 <10 8 2.3 14.9 2.2BS45 32B 163 4 14 .05 .2 1.4 .3 .04 8.2 <10 .04 <10 13 5.5 18.9 2.4

Tables 14–17 73
Table 15. Results of all elemental analyses performed by SGS Canada, Inc., Mineral Services, Toronto, Ontario, Canada, of sediment samples from six impoundments in the 

Assabet River Basin, Massachusetts, 2003.—Continued[Quantity in brackets is detection limit. Map ID: The identifier associated with a sampling site on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a replicate sample; DUP, SGS laboratory duplicate quality-control sample. %, percent; ppm, parts per million; <, actual value is less than value shown; --, not reported]

MapID Sample ID

Manganese

(ppm) 

[2]

Molybdenum

(ppm) 

[1]

Nickel

(ppm) 

[1]

Phosphorus

(%)

[0.01]

Potassium

(%)

[0.01]

Scandium

(ppm) 

[0.5]

Silver

(ppm) 

[0.2]

Sodium

(%)

[0.01]

Strontium

(ppm) 

[0.5]

Tin

(ppm) 

[10]

Titanium

(%)

[0.01]

Tungsten

(ppm) 

[10]

Vanadium 

(ppm) 

[2]

Yttrium 

(ppm) 

[0.5]

Zinc

(ppm) 

[0.5]

Zirconium

(ppm) 

[0.5]

Powdermill

P46 48 268 5 40 0.1 0.16 1.6 1.4 0.04 25.9 46 0.04 <10 27 5.5 289 3.3P46 48Q 263 7 41 .1 .15 1.5 1.5 .04 24.7 48 .04 <10 26 5.5 288 2.9P47 49 343 4 30 .09 .13 1.1 1.1 .04 22.7 43 .04 <10 22 4.6 152 1.6P48 46A 422 3 26 .15 .11 1.5 2.7 .03 18.9 61 .04 <10 28 5.8 162 2.3P48 46A-DUP 417 4 25 .15 .11 1.5 <.2 .04 19 65 .04 <10 25 4.7 155 2.9P48 46B 655 8 31 .04 .13 1.4 .5 .04 10.6 <10 .05 <10 30 5.2 75.2 1.8P48 46C 901 7 45 .03 .11 3 .4 .03 5.5 <10 .08 <10 38 8.7 47 3.6P49 47 199 7 27 .05 .2 1.1 .6 .04 13.4 23 .04 <10 18 3.6 59.3 3.5P50 52A 842 9 54 .26 .19 1.7 2 .04 35.2 42 .05 <10 34 6.8 331 2.5P50 52B 702 5 77 .28 .21 1.6 2 .03 25.9 59 .05 <10 38 6.3 298 1.9P50 52C 356 8 41 .12 .14 1 1.7 .03 17.6 64 .04 <10 30 4.2 183 2.1P50 52CQ 378 3 35 .13 .14 1 1.9 .02 18.1 75 .04 <10 30 4.3 174 1.2P50 52D 256 8 35 .09 .18 1.9 1.4 .03 18.1 62 .06 <10 33 5.8 306 6.7P50 52E 218 3 20 .07 .13 1.2 1.1 .03 17.7 234 .04 <10 21 4.6 93.2 1.8P50 52E-DUP 212 3 19 .07 .13 1.1 .9 .02 17.3 227 .04 <10 21 4.6 91.4 2.3P51 55A 117 9 60 .15 .09 1 > 10 .05 49.7 110 .02 <10 24 7.3 1,140 1.4P51 55AQ 135 12 69 .14 .09 1 > 10 .06 49.4 112 .03 <10 24 7.1 963 1.6P51 55B 86 4 24 .18 .09 1.1 2.8 .06 67 94 .03 <10 22 6.3 1,010 1.5P51 55B-DUP 87 4 25 .18 .1 1.2 3 .06 67.2 90 .03 <10 22 6.5 999 2.4P51 55C 53 4 51 .13 .04 .6 .5 .08 149 <10 <.01 <10 7 11.7 10.8 .5P51 55D 72 5 52 .05 .1 1.7 <.2 .04 51.7 <10 .02 <10 12 22.9 17.5 .6P52 53A 924 11 56 .31 .2 1.5 2 .05 40.9 38 .05 <10 33 7.1 354 2.8P52 53B 424 5 53 .18 .18 1.6 2.9 .04 30.6 82 .05 <10 40 6.9 339 2.7P52 53C 289 6 29 .17 .19 1.7 2.7 .04 37.6 89 .04 <10 30 5.7 726 4.6P52 53D 235 2 21 .09 .22 2.7 .9 .03 20.7 85 .07 <10 37 6.5 163 8.6P52 53DQ 230 4 23 .09 .21 2.6 .7 .03 20.1 68 .07 <10 36 6.3 158 8.4P52 53E 196 4 25 .06 .14 1.4 .5 .03 11.4 55 .05 <10 23 4.8 44.8 1.2P53 56A 306 7 272 .32 .19 2.6 8.6 .06 41.8 193 .05 134 49 11.4 379 2.8P53 56B 260 7 54 .3 .17 2 4.6 .04 37.2 91 .04 <10 39 8.4 424 2.5P53 56BQ 261 5 49 .3 .17 2 4.4 .04 36.9 90 .04 <10 39 8.3 430 2.2

74 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Table 15. Results of all elemental analyses performed by SGS Canada, Inc., Mineral Services, Toronto, Ontario, Canada, of sediment samples from six impoundments in the 

Assabet River Basin, Massachusetts, 2003.—Continued[Quantity in brackets is detection limit. Map ID: The identifier associated with a sampling site on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a replicate sample; DUP, SGS laboratory duplicate quality-control sample. %, percent; ppm, parts per million; <, actual value is less than value shown; --, not reported]

MapID Sample ID

Manganese

(ppm) 

[2]

Molybdenum

(ppm) 

[1]

Nickel

(ppm) 

[1]

Phosphorus

(%)

[0.01]

Potassium

(%)

[0.01]

Scandium

(ppm) 

[0.5]

Silver

(ppm) 

[0.2]

Sodium

(%)

[0.01]

Strontium

(ppm) 

[0.5]

Tin

(ppm) 

[10]

Titanium

(%)

[0.01]

Tungsten

(ppm) 

[10]

Vanadium 

(ppm) 

[2]

Yttrium 

(ppm) 

[0.5]

Zinc

(ppm) 

[0.5]

Zirconium

(ppm) 

[0.5]

Powdermill—Continued

P53 56C 299 3 26 0.16 0.16 2.2 0.3 0.02 32.9 83 0.04 <10 27 6.3 1,010 3.4P54 54A 294 15 69 .31 .17 1.5 > 10 .04 51.6 560 .03 <10 28 8.3 905 3.2P54 54B 355 3 14 .12 .03 .7 <.2 .04 109 15 <.01 <10 10 6.6 388 <.5P54 54C 243 4 10 .04 .04 3.2 .4 .03 119 <10 .01 <10 11 14.2 62.6 .7P54 54CQ 210 3 10 .03 .04 2.5 .2 .02 96.2 <10 .01 <10 9 10.5 73 .9P55 51A 384 6 46 .1 .12 1.6 1.3 .05 25.5 14 .04 <10 26 6.5 99.6 1.8P55 51B 330 3 21 .08 .06 1.8 .4 .04 14.5 <10 .04 <10 28 9.7 33.2 .5P55 51BQ 342 4 19 .08 .06 1.8 .4 .04 14.8 <10 .05 <10 29 10.1 34.1 <.5P55 51C 323 3 22 .05 .06 1.9 .4 .04 9.4 <10 .05 <10 31 9.9 31.4 .9P55 51D 282 8 29 .04 .07 2.1 .4 .04 6.9 <10 .06 <10 28 9 28.7 1.1P55 51E 267 4 30 .04 .05 2.8 .6 .04 7.1 <10 .05 <10 25 8.7 29.3 1.3P56 50A 583 9 179 .37 .26 2.3 > 10 .08 58 125 .05 117 40 11.7 572 2.2P56 50AQ 573 8 164 .36 .25 2.3 > 10 .07 56.3 116 .04 114 39 11.4 555 2.7P56 50B 704 14 84 .54 .23 2.4 > 10 .06 77.8 83 .04 <10 53 15.6 1,200 2.1P56 50C 308 4 28 .13 .26 2.8 2.2 .04 32.8 55 .06 <10 39 8.3 703 7P56 50D 262 5 26 .08 .12 1.7 .2 .04 24 16 .04 <10 25 7.4 48.2 1.3P56 50E 148 2 13 .06 .05 .7 .3 .03 19.5 <10 <.01 <10 6 9.5 10.3 <.5P56 50E-DUP 148 2 13 .06 .05 .7 .3 .02 19.5 <10 <.01 <10 6 9.6 9.4 .8P57 57 272 3 30 .07 .31 1.9 .5 .04 9.6 <10 .07 <10 28 6.1 66.9 4.2P57 57Q 252 4 36 .05 .3 2.3 .3 .04 7.6 <10 .08 <10 31 5.5 67.5 4

Tables 14–17 75
Table 16. Concentrations of polycyclic aromatic hydrocarbons detected in sediment samples from six impoundments in the Assabet 

River Basin, Massachusetts, 2003.—Continued

[All values are in micrograms per kilogram. Minimum reporting level is 0.017 micrograms per kilogram. Data are rounded to two significant figures. Map ID:

The identifier associated with a sampling site on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a replicate sample. Shaded numbers exceed sediment-quality guidelines (table 2). There are no guidelines 

for benzo[b]fluoranthene. PAH, polycyclic aromatic hydrocarbon; --, not detected]

Map 

ID

Sample 

ID

AcenaphtheneAcenaphthyleneAnthracene

Benzo[a]-

anthracene

Benzo[a]-

pyrene

Benzo[b]-

fluoranthene

Benzo[g,h,i]-

perylene

Benzo[k]-

fluorantheneChrysene

Aluminum City

AC1 5 23 5.2 77 290 220 310 110 130 330

AC2 7 21 8.8 25 220 210 330 120 180 360

AC3 6 19 9.9 29 150 190 400 110 130 250

AC4 8A 27 -- 44 440 390 670 220 320 640

AC4 8B 16 5.5 18 110 120 210 76 120 160

AC4 8C 4.7 -- 16 67 42 70 23 34 65

Allen Street

AS5 1 540 70 1,100 7,100 5,600 6,200 2,200 2,400 7,100

AS6 3 43 17 120 840 510 650 230 360 740

AS7 2A 74 39 290 1,500 1,200 1,500 560 760 1,300

AS7 2B 200 57 600 2,000 1,600 2,200 600 800 2,300

AS7 2C 20 15 76 540 290 380 140 200 480

AS8 4 58 19 160 750 560 780 260 380 840

Hudson

H9 9 -- -- 30 12 -- 23 12 9.0 19

H10 12 130 590 830 5,800 7,000 8,400 3,700 4,200 8,400

H10 12Q 120 520 740 5,400 6,000 7,900 3,600 3,100 7,700

H11 13 -- 13 16 160 160 250 130 110 250

H12 11A -- -- -- 12 -- 14 10 11 20

H12 11B -- -- -- 6.7 -- 11 6.5 5.4 9.2

H13 14A 81 380 660 5,300 6,000 9,600 2,100 2,900 6,400

H13 14AQ 76 390 610 4,500 5,200 8,100 2,000 3,400 5,500

H13 14B 32 230 310 2,600 2,900 3,900 1,200 1,800 3,000

H13 14BQ 33 240 360 3,200 3,500 5,400 1,400 2,500 3,800

H13 14C -- -- -- -- -- 117 -- -- 111

H13 14CQ -- -- -- -- -- 133 -- -- 131

H14 10 -- -- -- 5.0 -- 9.6 5.31 5.33 10

H15 15 -- 82 120 920 970 1,500 760 570 1,400

Gleasondale

G16 34 -- -- -- 20 -- 32 13 15 30

G17 39 14 11 51 220 260 310 140 220 350

G18 35A 410 610 1,500 7,400 7,800 10,000 4,400 5,500 11,000

G18 35B 220 270 1,200 6,400 5,700 6,100 2,800 3,800 8,800

G18 35C 34 41 190 920 740 770 370 640 1,300

76 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Table 16. Concentrations of polycyclic aromatic hydrocarbons detected in sediment samples from six impoundments in the Assabet 

River Basin, Massachusetts, 2003.—Continued

[All values are in micrograms per kilogram. Minimum reporting level is 0.017 micrograms per kilogram. Data are rounded to two significant figures. Map ID:

The identifier associated with a sampling site on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a replicate sample. Shaded numbers exceed sediment-quality guidelines (table 2). There are no guidelines 

for benzo[b]fluoranthene. PAH, polycyclic aromatic hydrocarbon; --, not detected]

Map 

ID

Sample 

ID

AcenaphtheneAcenaphthyleneAnthracene

Benzo[a]-

anthracene

Benzo[a]-

pyrene

Benzo[b]-

fluoranthene

Benzo[g,h,i]-

perylene

Benzo[k]-

fluorantheneChrysene

Gleasondale—Continued

G19 40A 47 46 160 770 800 1,200 470 440 1,200

G19 40B 150 120 470 2,500 2,500 3,200 1,300 2,100 3,800

G19 40C 10 8.41 57 220 190 260 110 160 320

G19 40CQ 14 11 86 310 270 350 140 220 440

G20 36 -- -- -- 20 -- 19 -- 14 28

G20 36Q -- -- -- 14 -- 16 7.10 12 26

G21 44 6.1 6.2 31 140 140 190 78 140 220

G22 41 63 60 210 1,300 1,300 1,700 700 1,200 2,000

G23 37 6.0 9.3 36 260 190 190 97 130 260

G24 42 9.8 14 32 230 230 310 140 210 380

G25 45 -- -- 8.6 74 81 120 51 76 120

G26 38 -- -- 60 190 190 290 160 180 330

G27 43 -- -- 54 180 210 330 140 210 320

Ben Smith

BS28 16 -- -- -- 55 47 184 39 37 179

BS29 18 -- -- -- 145 -- 196 74 54 89

BS30 17A -- 150 270 2,200 2,300 3,500 1,900 1,500 3,400

BS30 17B -- -- 150 1,200 880 1,500 750 650 1,600

BS30 17C -- -- -- -- -- 136 -- -- 138

BS31 19A -- -- -- -- -- 133 35 -- 27

BS31 19AQ -- -- -- -- -- 115 9.8 -- --

BS31 19B -- -- -- 220 160 330 160 130 440

BS31 19BQ -- -- 58 210 120 1230 100 100 380

BS31 19C -- -- 270 2,000 1,700 3,200 1,400 1,100 3,400

BS31 19CQ -- 91 240 1,600 1,500 2,500 1,200 1,300 2,600

BS32 20A -- -- 59 550 550 930 470 460 940

BS32 20B -- -- -- 42 -- 52 28 45 70

BS32 20C -- -- -- 18 -- 22 -- 19 28

BS33 21 -- -- 94 410 460 690 410 510 690

BS34 22 -- 28 39 350 380 590 320 360 610

BS35 23 -- -- 26 84 -- 120 70 100 160

BS36 27 -- -- -- 18 -- 18 -- 20 34

BS37 29 -- -- -- 8.01 -- 15 -- 14 12

BS38 26A -- -- 90 740 690 1,300 640 630 1,500

Tables 14–17 77
Table 16. Concentrations of polycyclic aromatic hydrocarbons detected in sediment samples from six impoundments in the Assabet 

River Basin, Massachusetts, 2003.—Continued

[All values are in micrograms per kilogram. Minimum reporting level is 0.017 micrograms per kilogram. Data are rounded to two significant figures. Map ID:

The identifier associated with a sampling site on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a replicate sample. Shaded numbers exceed sediment-quality guidelines (table 2). There are no guidelines 

for benzo[b]fluoranthene. PAH, polycyclic aromatic hydrocarbon; --, not detected]

Map 

ID

Sample 

ID

AcenaphtheneAcenaphthyleneAnthracene

Benzo[a]-

anthracene

Benzo[a]-

pyrene

Benzo[b]-

fluoranthene

Benzo[g,h,i]-

perylene

Benzo[k]-

fluorantheneChrysene

Ben Smith—Continued

BS38 26B -- -- 8.3 54 -- 78 42 58 110

BS38 26C -- -- -- -- -- -- -- -- --

BS39 25 -- -- -- 42 -- 50 29 43 63

BS40 24 -- 16 26 230 240 410 200 200 440

BS41 28 -- -- -- -- -- -- -- -- --

BS42 33 -- -- -- 97 92 130 75 87 140

BS43 30A -- -- -- 680 760 940 590 870 1,100

BS43 30B -- -- -- 520 400 630 310 460 740

BS43 30C -- -- -- -- -- 11 -- -- 10

BS44 31 -- -- -- 6.0 -- 8.3 -- 5.0 8.2

BS45 32 -- -- -- 26 25 51 22 20 35

Powdermill

P46 48 270 160 1,100 4,100 4,500 4,400 2,200 2,300 5,000

P46 48Q 250 150 1,400 4,600 4,900 5,000 1,800 2,900 5,600

P47 49 270 120 590 3,100 4,100 3,700 1,800 2,700 3,800

P48 46A -- -- -- -- -- -- -- -- --

P48 46B -- 13 38 700 740 680 320 280 730

P48 46C 140 300 730 7,400 8,400 6,800 5,800 2,600 7,200

P49 47 69 30 170 600 670 730 360 490 590

P50 52 7,500 780 81,000 120,000 74,000 82,000 25,000 38,000 10,000

P51 55 110 67 400 2,400 1,700 2,100 630 1,200 2,700

P52 53 2,800 -- 8,600 15,000 13,000 9,300 8,200 5,200 14,000

P53 56 790 360 3,000 9,400 8,700 6,700 3,900 5,200 11,000

P54 54A 260 230 1,500 10,000 9,300 10,000 4,300 3,700 13,000

P54 54B -- -- 120 510 380 300 270 260 550

P54 54C -- -- 16 50 38 110 64 43 140

P55 51A 75 25 320 1,100 1,200 930 710 350 1,200

P55 51B 7.1 -- 5.2 6.5 5.5 4.4 3.2 3.0 7.2

P55 51C -- -- 7.1 15 18 9.9 7.2 6.9 13

P56 50A 150 95 350 2,000 2,400 3,000 1,200 2,300 2,900

P56 50AQ 22 16 46 300 310 450 270 170 400

P56 50B 730 140 3,300 6,600 5,300 6,000 2,900 2,100 7,600

P56 50C 22 -- 54 130 95 90 48 76 130

P57 57 -- -- 2.0 11 14 21 10 12 20

78 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Table 16. Concentrations of polycyclic aromatic hydrocarbons detected in sediment samples from six impoundments in the Assabet 

River Basin, Massachusetts, 2003.—Continued

[All values are in micrograms per kilogram. Minimum reporting level is 0.017 micrograms per kilogram. Data are rounded to two significant figures. Map ID:

The identifier associated with a sampling site on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a replicate sample. Shaded numbers exceed sediment-quality guidelines (table 2). There are no guidelines 

for benzo[b]fluoranthene. PAH, polycyclic aromatic hydrocarbon; --, not detected]

Map ID Sample 

ID

Dibenzo[a,h]-

anthracene

Fluoranthene Fluorene

Indeno-

[1,2,3-cd]-

pyrene

Naphthalene Phenanthrene Pyrene Total PAH

Aluminum City

AC1 5 28 570 60 100 16 390 650 3,300

AC2 7 27 530 35 110 25.0 270 710 3,200

AC3 6 31 490 37 100 26 220 490 2,700

AC4 8A 52 960 41 200 29 410 1,100 5,500

AC4 8B 16 300 22 68 22 150 320 1,700

AC4 8C 5.2 130 10 20 5.0 74 150 720

Allen Street

AS5 1 710 7,300 670 2,000 460 3,400 11,000 58,000

AS6 3 61 1,100 73 220 37 550 1,200 6,800

AS7 2A 140 2,700 150 520 75 1,700 3,300 16,000

AS7 2B 170 3,200 330 600 130 2,500 4,000 21,000

AS7 2C 36 700 36 130 55 440 920 4,500

AS8 4 64 1,300 86 250 55 970 1,700 8,200

Hudson

H9 9 -- 24 -- 9.6 -- 30 24 190

H10 12 900 9,900 740 3,500 420 6,600 16,000 77,000

H10 12Q 900 11,000 610 3,200 370 6,100 13,000 70,000

H11 13 25 310 11 110 11 140 370 2,100

H12 11A -- 21 -- 8.7 -- 12 26 130

H12 11B -- 15 -- 5.3 -- 8.4 15 82

H13 14A 610 12,000 410 2,400 220 3,800 14,000 67,000

H13 14AQ 570 11,000 340 2,200 130 3,500 13,000 61,000

H13 14B 330 3,900 180 1,300 160 1,700 6,400 30,000

H13 14BQ 380 7,200 190 1,500 170 2,000 8,200 40,000

H13 14C -- 118 -- -- -- 13 117 13

H13 14CQ -- 146 -- -- -- 40 142 40

H14 10 -- 17 -- 4.2 -- 11 14 82

H15 15 140 1,700 71 670 69 950 2,000 12,000

Gleasondale

G16 34 -- 63 -- 12 -- 45 48 280

G17 39 45 460 29 130 20 290 650 3,200

G18 35A 620 14,000 1,000 4,200 690 9,700 20,000 99,000

G18 35B 470 12,000 720 2,800 380 7,800 16,000 75,000

G18 35C 55 1,700 76 340 100 1100 2,200 11,000

G19 40A 85 1,400 96 430 82 880 2,200 10,000

G19 40B 420 5,600 420 1,300 290 3,800 7,100 35,000

G19 40C 36 400 24 100 32 260 520 2,700

G19 40CQ 46 550 34 130 45 350 740 3,700

G20 36 -- 37 -- -- -- 20 40 180

Tables 14–17 79
Table 16. Concentrations of polycyclic aromatic hydrocarbons detected in sediment samples from six impoundments in the Assabet 

River Basin, Massachusetts, 2003.—Continued

[All values are in micrograms per kilogram. Minimum reporting level is 0.017 micrograms per kilogram. Data are rounded to two significant figures. Map ID:

The identifier associated with a sampling site on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a replicate sample. Shaded numbers exceed sediment-quality guidelines (table 2). There are no guidelines 

for benzo[b]fluoranthene. PAH, polycyclic aromatic hydrocarbon; --, not detected]

Map ID Sample 

ID

Dibenzo[a,h]-

anthracene

Fluoranthene Fluorene

Indeno-

[1,2,3-cd]-

pyrene

Naphthalene Phenanthrene Pyrene Total PAH

Gleasondale—Continued

G20 36Q -- 35 -- 7.8 -- 19 39 180

G21 44 23 260 10 74 7.10 120 320 1,800

G22 41 210 2,500 140 660 120 1,600 3,600 17,000

G23 37 18 330 15 95 15 190 530 2,400

G24 42 45 430 22 120 20 290 700 3,200

G25 45 15 140 5.7 46 5.98 54 220 1,000

G26 38 38 450 -- 130 -- 250 550 2,800

G27 43 47 420 21 120 17 190 500 2,800

Ben Smith

BS28 16 10 187 -- 34 -- 37 1140 260

BS29 18 -- 1110 -- 43 -- 69 1130 330

BS30 17A 360 4,100 230 1,600 150 2,600 6,300 31,000

BS30 17B 140 1,800 110 650 97 1,100 2,600 13,000

BS30 17C -- 170 -- -- -- 39 144 39

BS31 19A -- 125 -- 28 -- -- -- 90

BS31 19AQ -- 116 -- -- -- 14 112 24

BS31 19B -- 390 -- 140 -- 280 650 2,900

BS31 19BQ -- 410 -- 81 -- 300 660 2,400

BS31 19C 280 3,500 220 1,300 200 2,100 5,400 26,000

BS31 19CQ 250 2,900 180 1,100 130 1,700 4,000 21,000

BS32 20A 80 910 46 390 -- 570 1,300 7,300

BS32 20B -- 76 -- 23 -- 45 120 500

BS32 20C -- 27 -- -- -- 13 22 150

BS33 21 130 780 37 350 -- 430 820 5,800

BS34 22 90 600 31 280 35 350 1,100 5,200

BS35 23 -- 160 -- 60 -- 100 280 1,200

BS36 27 -- -- -- -- -- -- 15 110

BS37 29 -- 13 -- -- -- 12 15 89

BS38 26A 150 1,400 79 560 89 670 2,200 11,000

BS38 26B 13 69 11 35 9.59 64 150 700

BS38 26C -- -- -- -- -- -- -- --

BS39 25 -- 82 -- 25 -- 69 130 530

BS40 24 50 460 21 170 21 270 740 3,500

BS41 28 -- -- -- -- -- -- -- --

BS42 33 -- 150 -- 67 -- 79 260 1,200

BS43 30A -- 1,300 -- 560 -- 770 2,000 9,600

BS43 30B -- 770 -- 280 -- 450 1,100 5,700

BS43 30C -- 19 -- -- -- 13 17 70

BS44 31 -- -- -- -- -- 5.88 12 45

BS45 32 -- 47 -- 20 -- 21 67 330

80 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Table 16. Concentrations of polycyclic aromatic hydrocarbons detected in sediment samples from six impoundments in the Assabet 

River Basin, Massachusetts, 2003.—Continued

[All values are in micrograms per kilogram. Minimum reporting level is 0.017 micrograms per kilogram. Data are rounded to two significant figures. Map ID:

The identifier associated with a sampling site on a map (figs. 9–14). Sample ID: Identifier for a sample collected from a particular core, arranged alphabetically from the top of the core, with Q designating a replicate sample. Shaded numbers exceed sediment-quality guidelines (table 2). There are no guidelines 

for benzo[b]fluoranthene. PAH, polycyclic aromatic hydrocarbon; --, not detected]

Map ID Sample 

ID

Dibenzo[a,h]-

anthracene

Fluoranthene Fluorene

Indeno-

[1,2,3-cd]-

pyrene

Naphthalene Phenanthrene Pyrene Total PAH

Powdermill

P46 48 580 6,100 350 1,800 710 3,000 11,000 48,000

P46 48Q 470 6,500 360 1,600 700 3,300 10,000 50,000

P47 49 480 5,500 310 1,600 350 3,800 7,800 40,000

P48 46A -- 3.4 -- -- -- -- 3.8 7.2

P48 46B 71 300 10 240 16 110 940 5,200

P48 46C 1,200 5,900 260 4,200 550 3,000 11,000 65,000

P49 47 92 1,100 84 310 78 770 1,600 7,700

P50 52 10,000 200,000 18,000 29,000 1,300 150,000 210,000 1,100,000

P51 55 140 2,900 140 540 200 700 4,700 21,000

P52 53 1,600 20,000 3,500 5,400 2,200 29,000 40,000 180,000

P53 56 1,100 12,000 1,100 320 920 9,200 22,000 96,000

P54 54A 930 12,000 500 3,500 590 5,700 23,000 99,000

P54 54B -- 700 -- 180 -- 560 1,500 5,300

P54 54C -- 210 -- 22 -- 74 460 1,200

P55 51A 130 1,500 67 460 70 550 3,600 12,000

P55 51B -- 11 -- -- 3.5 12 25 94

P55 51C -- 17 -- 5.3 -- 15 29 140

P56 50A 310 4,100 210 1,100 260 2,200 6,900 29,000

P56 50AQ 54 550 29 220 29 290 810 4,000

P56 50B 580 10,000 1,000 2,100 1,200 9,700 19,000 78,000

P56 50C 9.6 150 20 30 11 180 480 1,500

P57 57 -- 25 -- 9.3 -- 12 26 160

1

Indicates suspected laboratory contamination

Tables 14–17 81
Table 17. Water-quality data collected during study of phosphorus dynamics in the Hudson, Massachusetts, impoundment, 

2003.—Continued

[cm, centimeter; m, meter; mg/L, milligram per liter; μS/cm, microsiemens per centimeter; °C, degrees Celsius; --, no data]

Date Time Depth

(m)

Specific

conductance

(μS/cm)

pH 

 Temperature

(°C)

Dissolved

oxygen

(mg/L)

Chloride

(mg/L)

Total

phosphorus

(mg/L)

Orthophosphorus

(mg/L)

Remarks

Station 17

7-16-03 9:00 0.00 594 6.86 21.8 6.4 -- 0.1010 0.051

7-16-03 .50 594 6.83 21.8 6.4 -- -- --

7-16-03 9:10 1.00 594 6.83 21.8 6.4 -- .1081 .051

7-16-03 1.50 594 6.82 21.8 6.4 -- -- --

7-16-03 1.60 594 6.81 21.8 6.3 -- -- --

7-24-03 8:40 .00 514 -- 22.0 4.1 118.02 .1451 .075

7-24-03 .50 515 -- 22.0 4.1 -- -- --

7-24-03 1.00 515 -- 22.0 4.1 -- -- --

7-24-03 8:50 1.50 515 -- 22.0 4.1 -- .1582 .077

7-24-03 1.80 515 -- 22.0 4.1 -- -- --

7-29-03 8:50 .00 601 -- 23.3 6.4 142.44 .0846 .054

7-29-03 .50 601 -- 23.3 5.7 -- -- --

7-29-03 1.00 600 -- 23.3 5.8 -- -- --

7-29-03 9:00 1.50 600 -- 23.3 5.8 -- .0861 .055

7-29-03 1.80 601 -- 23.3 5.7 -- -- --

8-07-03 9:10 .00 485 6.42 23.2 3.8 109.64 .1523 .109

8-07-03 9:11 -- -- -- -- 109.37 .1526 .108 Replicate

8-07-03 .50 486 6.44 23.2 3.8 -- -- --

8-07-03 1.00 486 6.45 23.2 3.8 -- -- --

8-07-03 9:20 1.50 486 6.47 23.2 3.7 -- .1498 .109

8-07-03 1.80 486 6.47 23.2 3.7 -- -- --

8-13-03 9:40 .00 500 6.56 23.9 4.6 111.83 .1365 .095

8-13-03 9:55 .50 499 6.62 23.9 4.2 .2 .002 .001

8-13-03 1.00 499 6.62 23.9 4.2 -- -- --

8-13-03 1.50 499 6.65 23.9 4.0 -- -- --

8-21-03 9:25 .00 528 6.57 21.7 6.2 122.15 .1056 .075

8-21-03 .50 525 6.6 22.8 5.6 -- -- --

8-21-03 1.00 522 6.63 22.8 5.4 -- -- --

8-21-03 9:35 1.40 523 6.64 22.8 5.3 .1068 .076

8-28-03 9:40 .00 687 6.4 21.5 5.4 162.2 .0821 .055

8-28-03 .50 687 6.43 21.6 5.2 -- -- --

8-28-03 1.00 687 6.51 21.5 5.1 -- -- --

8-28-03 9:50 1.50 687 6.56 21.5 5.1 .1283 .055

9-08-03 9:00 .00 631 6.48 19.4 6.6 146.58 .0823 .046

9-08-03 .50 631 6.49 19.4 6.6 -- -- --

9-08-03 1.00 631 6.5 19.4 6.6 -- -- --

9-08-03 9:20 1.50 631 6.5 19.4 6.6 -- .4200 .047

9-08-03 9:21 -- -- -- -- <.2 .0029 .000 Blank

9-08-03 1.70 631 6.5 19.4 6.5 -- -- --

82 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Table 17. Water-quality data collected during study of phosphorus dynamics in the Hudson, Massachusetts, impoundment, 

2003.—Continued

[cm, centimeter; m, meter; mg/L, milligram per liter; μS/cm, microsiemens per centimeter; °C, degrees Celsius; --, no data]

Date Time Depth

(m)

Specific

conductance

(μS/cm)

pH 

 Temperature

(°C)

Dissolved

oxygen

(mg/L)

Chloride

(mg/L)

Total

phosphorus

(mg/L)

Orthophosphorus

(mg/L)

Remarks

Station 20

7-16-03 9:45 0.00 578 7.53 22.5 7.1 -- 0.1044 0.040

7-16-03 .50 578 7.57 22.5 7.0 -- -- --

7-16-03 9:55 .70 583 6.92 22.5 7.0 -- .2800 .060

7-16-03 10:00 1-.05 -- -- -- -- -- 2.3350 .383

7-24-03 9:15 .00 576 -- 22.1 3.0 137.17 .0750 .033

7-24-03 .50 574 -- 22.7 2.3 -- -- --

7-24-03 9:25 .70 602 -- 22.5 .7 -- .2550 .054

7-24-03 9:35 1-.05 -- -- -- -- 7.0770 5.016

7-29-03 9:20 .00 529 -- 23.9 9.9 128.64 .0764 .049

7-29-03 9:30 .50 527 -- 23.5 5.5 -- .2200 .108

7-29-03 9:40 .80 590 -- 23.1 .4 -- 3.1220 1.153

7-29-03 9:50 1-.05 -- -- -- -- -- 1.2210 .873

8-07-03 10:00 .00 470 6.63 24.0 3.4 107.41 .1006 .070

8-07-03 10:10 .50 473 6.49 23.6 1.3 -- .1524 .096

8-07-03 10:20 .90 537 6.41 23.0 .2 -- .3130 .135

8-07-03 10:30 1-.05 -- -- -- -- -- 2.1320 1.153

8-13-03 10:25 .00 485 6.91 25.6 6.4 110.8 .0717 .053

8-13-03 .50 501 6.68 24.6 1.8 -- -- --

8-13-03 10:35 .70 505 6.64 24.4 1.5 -- .1731 .126

8-13-03 10:45 1-.05 -- -- -- -- -- .9490 .716

8-21-03 10:00 .00 501 6.73 24.0 4.1 118.2 .0969 .057

8-21-03 10:10 .50 499 6.51 23.1 2.0 -- .1507 .088

8-21-03 10:15 .70 516 6.29 22.8 .3 -- .8120 .713

8-21-03 10:20 1-.05 -- -- -- -- -- 2.1320 .605

8-28-03 10:15 .00 562 6.94 21.8 5.7 128.18 .0569 .037

8-28-03 .50 567 6.73 21.1 3.2 -- -- --

8-28-03 10:25 .70 567 6.66 21.1 2.6 -- .3350 .061

8-28-03 10:35 1-.05 -- -- -- -- -- .7740 .145

9-08-03 10:00 .00 602 6.78 19.8 8.4 139.43 .0562 .023

9-08-03 10:10 .50 604 6.52 19.4 4.4 139.41 .2140 .047

9-08-03 10:20 .85 631 6.36 19.0 .6 -- 1.1150 .093

9-08-03 10:30 1-.05 -- -- -- -- -- .9120 .296

9-08-03 10:31 1-.05 -- -- -- -- -- .9400 .292

Station 27

7-16-03 10:35 0.00 600 7.9 22.7 7.2 -- 0.0968 0.036

7-16-03 .50 595 7.72 22.6 7.1 -- -- --

7-16-03 10:45 1.00 572 5.62 22.2 6.7 -- .1213 .049

7-16-03 1.10 571 5.08 22.2 6.6 -- -- --

7-16-03 10:55 1-.05 -- -- -- -- -- 1.2060 .310

Tables 14–17 83
Table 17. Water-quality data collected during study of phosphorus dynamics in the Hudson, Massachusetts, impoundment, 

2003.—Continued

[cm, centimeter; m, meter; mg/L, milligram per liter; μS/cm, microsiemens per centimeter; °C, degrees Celsius; --, no data]

Date Time Depth

(m)

Specific

conductance

(μS/cm)

pH 

 Temperature

(°C)

Dissolved

oxygen

(mg/L)

Chloride

(mg/L)

Total

phosphorus

(mg/L)

Orthophosphorus

(mg/L)

Remarks

Station 27—Continued

7-24-03 10:00 0.00 609 -- 22.9 7.0 147.49 0.1204 0.031

7-24-03 .50 601 -- 22.8 7.0 -- -- --

7-24-03 10:05 1.00 638 -- 22.3 2.5 -- .1713 .057

7-24-03 1.20 638 -- 22.2 .3 -- -- --

7-29-03 10:10 .00 571 -- 24.4 7.7 136.3 .1280 .076

7-29-03 .50 576 -- 24.0 7.7 -- -- --

7-29-03 10:20 1.00 552 -- 23.6 5.3 -- .2570 .155

7-29-03 1.20 571 -- 23.5 .8 -- -- --

7-29-03 10:30 1-.05 -- -- -- -- 1.2980 .446

8-07-03 10:40 .00 491 6.63 24.4 5.6 111.71 .1380 .095

8-07-03 .50 515 6.61 24.0 5.4 -- -- --

8-07-03 10:50 1.00 585 6.45 23.4 2.3 -- .1133 .072

8-07-03 1.30 565 6.42 23.0 1.5 -- -- --

8-07-03 11:00 1-.05 -- -- -- -- -- .5470 .216

8-07-03 11:01 1-.05 -- -- -- -- -- .3630 .236 Replicate

8-13-03 11:00 .00 501 6.7 25.1 4.4 118.29 .1369 .085

8-13-03 11:10 .50 510 6.7 24.6 3.4 -- .0899 .066

8-13-03 1.00 544 6.71 23.6 3.1 -- -- --

8-13-03 11:20 1-.05 -- -- -- -- -- .9030 .371

8-21-03 10:50 .00 483 6.59 23.8 5.9 120.12 .1166 .082

8-21-03 .50 491 6.44 23.1 3.5 -- -- --

8-21-03 11:00 1.00 487 6.29 22.7 1.3 -- .2010 .128

8-21-03 1.50 514 6.31 22.5 .3 -- -- --

8-21-03 11:10 1-.05 -- -- -- -- -- .6480 .368

8-28-03 10:50 .00 575 7.08 22.3 6.9 133.7 .1032 .047

8-28-03 .50 559 6.93 21.5 5.2 -- -- --

8-28-03 1.00 565 6.8 21.3 5.0 -- -- --

8-28-03 11:00 1.20 -- -- -- -- -- .3900 .295

8-28-03 11:10 1-.05 -- -- -- -- -- .6540 .323

9-08-03 11:15 .00 610 6.84 20.5 8.9 143.02 .0747 .030

9-08-03 .50 613 6.73 20.2 8.3 -- -- --

9-08-03 11:25 1.00 621 6.62 19.9 7.0 -- .1136 .038

9-08-03 1.10 620 6.6 20.0 6.4 -- -- --

9-08-03 11:35 1-.05 -- -- -- -- -- .6110 .237

Station 29

7-16-03 11:10 0.00 602 8.2 22.7 7.1 -- 0.0720 0.028

7-16-03 .50 601 8.38 22.7 7.1 -- -- --

7-16-03 11:20 1.00 604 5.45 22.4 6.8 -- .2650 .027

7-16-03 1.20 606 4.34 22.2 6.7 -- -- --

7-16-03 11:30 1-.05 -- -- -- -- -- 1.2090 .267

84 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Table 17. Water-quality data collected during study of phosphorus dynamics in the Hudson, Massachusetts, impoundment, 

2003.—Continued

[cm, centimeter; m, meter; mg/L, milligram per liter; μS/cm, microsiemens per centimeter; °C, degrees Celsius; --, no data]

Date Time Depth

(m)

Specific

conductance

(μS/cm)

pH 

 Temperature

(°C)

Dissolved

oxygen

(mg/L)

Chloride

(mg/L)

Total

phosphorus

(mg/L)

Orthophosphorus

(mg/L)

Remarks

Station 29—Continued

7-24-03 10:48 -- -- -- -- 0.2 0.0040 0.005 Blank

7-24-03 11:00 0.00 535 -- 22.7 8.0 127.26 .1100 .044

7-24-03 .50 528 -- 22.4 5.8 -- -- --

7-24-03 11:10 1.00 527 -- 22.2 4.3 -- .3130 .071

7-24-03 1.10 848 -- 22.0 .2 -- -- --

7-29-03 10:50 .00 593 -- 26.1 12.1 142.29 .0770 .049

7-29-03 .50 599 -- 24.3 5.5 -- -- --

7-29-03 11:00 1.00 604 -- 24.1 4.3 -- .2070 .075

7-29-03 1.20 642 -- 24.0 .4 -- -- --

7-29-03 11:10 1-.05 -- -- -- 1.4460 .222

8-07-03 11:20 .00 485 6.59 24.2 5.6 109.23 .1446 .101

8-07-03 .50 487 6.53 23.8 4.9 -- -- --

8-07-03 11:30 1.00 487 6.55 23.7 4.7 -- .1494 .123

8-07-03 1.30 496 6.54 23.6 3.4 -- -- --

8-07-03 11:40 1-.05 -- -- -- -- -- .9550 .578

8-13-03 11:40 .00 504 6.72 25.6 5.8 116.28 .1279 .090

8-13-03 .50 508 6.78 24.4 5.4 -- -- --

8-13-03 11:50 .90 513 6.81 24.2 4.9 -- .1405 .092

8-13-03 12:00 1-.05 -- -- -- -- -- 1.9810 .811

8-21-03 12:10 .00 499 7.11 24.8 8.7 121 .1601 --

8-21-03 .50 492 6.86 23.6 7.4 -- -- .065

8-21-03 12:20 1.00 494 6.67 23.3 6.2 -- .1657 .085

8-21-03 1.30 626 6.27 23.0 .2 -- -- --

8-21-03 12:30 1-.05 -- -- -- -- -- 1.1860 .659

8-28-03 11:35 .00 653 7.16 22.9 7.1 150.21 .0806 .039

8-28-03 .50 649 7.13 22.5 6.7 -- -- --

8-28-03 11:45 1.00 637 7.01 22.1 5.7 -- .7290 .039

8-28-03 1.20 637 6.95 22.0 5.1 --

8-28-03 11:55 1-.05 -- -- -- -- -- 1.5830 .271

9-08-03 12:00 .00 619 7.36 22.1 10.5 142.26 .0927 .039

9-08-03 .50 610 6.9 20.3 9.0 -- -- --

9-08-03 12:10 1.00 608 6.81 20.0 8.5 -- .1421 .039

9-08-03 1.10 608 6071 20.0 7.7 -- -- --

9-08-03 12:20 1-.05 -- -- -- -- -- .3550 .208

Station 37

7-16-03 12:00 0.00 600 7.43 22.6 6.9 -- 0.0990 0.042

7-16-03 .50 602 7.41 22.5 6.9 -- -- --

7-16-03 12:05 1.00 606 7.14 22.4 6.9 -- .0993 .044

7-16-03 1.50 608 6.84 22.2 6.9 -- -- --

7-16-03 12:10 2.00 608 6.45 22.0 6.8 -- .1122 .050

Tables 14–17 85
Table 17. Water-quality data collected during study of phosphorus dynamics in the Hudson, Massachusetts, impoundment, 

2003.—Continued

[cm, centimeter; m, meter; mg/L, milligram per liter; μS/cm, microsiemens per centimeter; °C, degrees Celsius; --, no data]

Date Time Depth

(m)

Specific

conductance

(μS/cm)

pH 

 Temperature

(°C)

Dissolved

oxygen

(mg/L)

Chloride

(mg/L)

Total

phosphorus

(mg/L)

Orthophosphorus

(mg/L)

Remarks

Station 37—Continued

7-16-03 2.50 607 6.22 22.0 6.8 -- -- --

7-16-03 12:15 3.00 607 6.13 22.0 6.8 -- 0.2930 0.052

7-24-03 11:50 .00 529 -- 22.4 4.1 121.72 .1372 .070

7-24-03 .50 531 -- 22.5 4.2 -- -- --

7-24-03 12:00 1.00 531 -- 22.4 4.2 -- .1378 .070

7-24-03 1.50 529 -- 22.3 4.0 -- -- --

7-24-03 12:05 2.00 528 -- 22.3 3.9 -- .1395 .072

7-24-03 2.50 528 -- 22.2 3.9 -- -- --

7-24-03 12:10 3.00 527 -- 22.2 3.9 -- .1411 .073

7-24-03 3.20 527 -- 22.2 3.9 -- -- --

7-29-03 11:30 .00 601 -- 25.4 7.2 141.89 .0911 .055

7-29-03 .50 602 -- 24.9 6.9 -- -- --

7-29-03 1.00 602 -- 24.4 6.6 -- -- --

7-29-03 1.50 599 -- 24.2 6.2 -- -- --

7-29-03 11:40 2.00 600 -- 24.1 6.2 -- .0906 .059

7-29-03 2.50 601 -- 24.1 6.1 -- -- --

7-29-03 11:50 3.00 601 -- 24.0 5.9 -- .1000 --

8-07-03 12:00 .00 483 6.32 24.8 5.4 108.93 .1520 .107

8-07-03 .50 484 6.3 24.3 4.8 -- -- --

8-07-03 1.00 486 6.19 23.9 4.2 -- -- --

8-07-03 1.50 486 6.24 23.8 4.0 -- -- --

8-07-03 12:10 2.00 487 6.26 23.6 3.8 -- .1554 .109

8-07-03 2.50 487 6.26 23.6 3.8 -- -- --

8-07-03 12:20 3.00 488 6.31 23.6 3.8 111.38 .1553 .109

8-13-03 12:30 .00 506 6.71 25.3 5.4 115.66 .1407 .094

8-13-03 .50 504 6.73 25.2 4.9 -- -- --

8-13-03 1.00 505 6.74 24.7 4.9 -- -- --

8-13-03 1.50 506 6.74 24.4 4.6 -- -- --

8-13-03 12:40 2.00 506 6.73 24.4 4.1 -- .1423 .095

8-13-03 2.50 550 6.72 24.4 4.1 -- -- --

8-13-03 12:50 3.00 506 6.72 24.3 3.9 114.08 .1456 .095

8-21-03 12:45 .00 497 6.79 25.1 6.8 120.69 .1038 .070

8-21-03 .50 497 6.77 25.1 6.7 -- -- --

8-21-03 1.00 493 6.7 23.9 6.2 -- -- --

8-21-03 1.50 491 6.64 23.4 5.7 -- -- --

8-21-03 2.00 491 6.61 23.3 5.5 -- -- --

8-21-03 2.50 490 6.59 23.2 5.4 -- -- --

8-21-03 13:00 3.00 490 6.59 23.2 5.3 -- .1316 .079

8-28-03 12:10 .00 656 7.03 22.8 6.1 150.53 .0867 .053

8-28-03 .50 659 6.99 22.6 5.8 -- -- --

86 Sediment Studies in the Assabet River, Central Massachusetts, 2003
Table 17. Water-quality data collected during study of phosphorus dynamics in the Hudson, Massachusetts, impoundment, 

2003.—Continued

[cm, centimeter; m, meter; mg/L, milligram per liter; μS/cm, microsiemens per centimeter; °C, degrees Celsius; --, no data]

Date Time Depth

(m)

Specific

conductance

(μS/cm)

pH 

 Temperature

(°C)

Dissolved

oxygen

(mg/L)

Chloride

(mg/L)

Total

phosphorus

(mg/L)

Orthophosphorus

(mg/L)

Remarks

Station 37—Continued

8-28-03 1.00 656 6.97 22.5 5.9 -- -- --

8-28-03 1.50 652 6.95 22.3 5.9 -- -- --

8-28-03 12:20 2.00 644 6.93 22.1 5.6 -- 0.0963 0.055

8-28-03 2.50 644 6.91 22.0 5.6 -- -- --

8-28-03 12:30 3.00 644 6.89 22.0 5.3 -- .1059 .056

9-08-03 12:45 .00 -- -- -- -- <0.2 .0037 .003 Blank

9-08-03 12:50 .00 623 6.76 21.2 8.0 143.79 .0805 .044

9-08-03 .50 623 6.7 20.2 7.4 -- -- --

9-08-03 1.00 623 6.67 20.1 7.0 -- -- --

9-08-03 1.50 625 6.65 19.9 7.0 -- -- --

9-08-03 13:00 2.00 628 6.64 19.8 6.8 -- .0883 .047

9-08-03 2.50 627 6.63 19.8 6.5 -- -- --

9-08-03 13:10 3.00 626 6.63 19.8 6.7 -- .0907 .048

1

-0.05, sample of pore water collected from 5 cm below sediment surface.

Tables 14–17 87



For additional information write to:

Director, 

USGS Massachusetts–Rhode Island Water Science Center

10 Bearfoot Road

Northborough, MA 01532

or visit our Web site at

http://ma.water.usgs.gov