Water Quality of Selected Rivers in the 

New England Coastal Basins in Maine, 

Massachusetts, New Hampshire, 

and Rhode Island, 1998-2000

By Kimberly W. Campo, Sarah M. Flanagan, and Keith W. Robinson

Pembroke, New Hampshire

2003

Water-Resources Investigations Report 03-4210

U.S. GEOLOGICAL SURVEY

NATIONAL WATER-QUALITY ASSESSMENT PROGRAM
U.S. DEPARTMENT OF THE INTERIOR

GALE A. NORTON, Secretary

U.S. GEOLOGICAL SURVEY

Charles G. Groat, Director

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.

For additional information write to:

District Chief

U.S. Geological Survey

New Hampshire/Vermont District

361 Commerce Way

Pembroke, NH 03275-3718

http://nh.water.usgs.gov

Copies of this report can be purchased from:

U.S. Geological Survey

Information Services

Building 810

Box 25286, Federal Center

Denver, CO 80225-0286
FOREWORD

The U.S. Geological Survey (USGS) is 

committed to serve the Nation with accurate and 

timely scientific information that helps enhance 

and protect the overall quality of life, and 

facilitates effective management of water, 

biological, energy, and mineral resources. 

(http://www.usgs.gov/). Information on the quality 

of the Nation’s water resources is of critical interest 

to the USGS because it is so integrally linked to the 

long-term availability of water that is clean and 

safe for drinking and recreation and that is suitable 

for industry, irrigation, and habitat for fish and 

wildlife. Escalating population growth and 

increasing demands for the multiple water uses 

make water availability, now measured in terms of 

quantity and quality, even more critical to the longterm sustainability of our communities and 

ecosystems.

The USGS implemented the National WaterQuality Assessment (NAWQA) Program to support 

national, regional, and local information needs and 

decisions related to water-quality management and 

policy. (http://water.usgs.gov/nawqa/). Shaped by 

and coordinated with ongoing efforts of other 

Federal, State, and local agencies, the NAWQA 

Program is designed to answer: What is the 

condition of our Nation’s streams and ground 

water? How are the conditions changing over time? 

How do natural features and human activities affect 

the quality of streams and ground water, and where 

are those effects most pronounced? By combining 

information on water chemistry, physical 

characteristics, stream habitat, and aquatic life, the 

NAWQA Program aims to provide science-based 

insights for current and emerging water issues and 

priorities. NAWQA results can contribute to 

informed decisions that result in practical and 

effective water-resource management and 

strategies that protect and restore water quality.

Since 1991, the NAWQA Program has 

implemented interdisciplinary assessments in more 

than 50 of the Nation’s most important river basins 

and aquifers, referred to as Study Units. 

(http://water.usgs.gov/nawqa/nawqamap.html). 

Collectively, these Study Units account for more 

than 60 percent of the overall water use and 

population served by public water supply, and are 

representative of the Nation’s major hydrologic 

landscapes, priority ecological resources, and 

agricultural, urban, and natural sources of 

contamination. 

Each assessment is guided by a nationally 

consistent study design and methods of sampling 

and analysis. The assessments thereby build local 

knowledge about water-quality issues and trends in 

a particular stream or aquifer while providing an 

understanding of how and why water quality varies 

regionally and nationally. The consistent, multiscale approach helps to determine if certain types 

of water-quality issues are isolated or pervasive, 

and allows direct comparisons of how human 

activities and natural processes affect water quality 

and ecological health in the Nation’s diverse 

geographic and environmental settings. 

Comprehensive assessments on pesticides, 

nutrients, volatile organic compounds, trace 

metals, and aquatic ecology are developed at the 

national scale through comparative analysis of the 

Study-Unit findings. 

(http://water.usgs.gov/nawqa/natsyn.html). 

The USGS places high value on the 

communication and dissemination of credible, 

timely, and relevant science so that the most recent 

and available knowledge about water resources can 

be applied in management and policy decisions. 

We hope this NAWQA publication will provide 

you the needed insights and information to meet 

your needs, and thereby foster increased awareness 

and involvement in the protection and restoration 

of our Nation’s waters. 

The NAWQA Program recognizes that a 

national assessment by a single program cannot 

address all water-resource issues of interest. 

External coordination at all levels is critical for a 

fully integrated understanding of watersheds and 

for cost-effective management, regulation, and 

conservation of our Nation’s water resources. The 

Program, therefore, depends extensively on the 

advice, cooperation, and information from other 

Federal, State, interstate, Tribal, and local 

agencies, non-government organizations, industry, 

academia, and other stakeholder groups. The 

assistance and suggestions of all are greatly 

appreciated.

Robert M. Hirsch

Associate Director for Water
iv Contents

CONTENTS

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

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

Purpose and Scope ..................................................................................................................................... 2

Description of the New England Coastal Basins Study Area .................................................................... 2

Acknowledgments ...................................................................................................................................... 6

Study Design ....................................................................................................................................................... 6

Indicator Basins .......................................................................................................................................... 6

Integrator Basins ........................................................................................................................................ 8

Data Collection and Analysis .............................................................................................................................. 9

Data Collection ........................................................................................................................................... 9

Data Analysis ............................................................................................................................................. 9

Water Quality of Selected New England Coastal Basins Rivers ........................................................................ 11

Streamflow Conditions ............................................................................................................................... 11

Field Measurements ................................................................................................................................... 11

Dissolved Ions ............................................................................................................................................ 14

Nutrients ..................................................................................................................................................... 17

Nitrogen ............................................................................................................................................ 17

Phosphorus ........................................................................................................................................ 17

Pesticides .................................................................................................................................................... 21

Volatile Organic Compounds .............................................................................................................................. 23

Water-Quality Conditions of Monitoring Sites in the New England Coastal Basins, Long Island-

 New Jersey Coastal Drainages, and Other National Water-Quality Assessment Program Urban Sites ........... 26

Nutrients ..................................................................................................................................................... 26

Pesticides .................................................................................................................................................... 26

Volatile Organic Compounds ..................................................................................................................... 26

Summary and Conclusions .................................................................................................................................. 30

References Cited ................................................................................................................................................. 32

Appendix 1. Constituents analyzed in surface-water samples from fixed sites in the New England 

 Coastal Basins study area, 1998-2000 ............................................................................................................... 40

Appendix 2. Pesticides and degradation products analyzed in surface-water samples from the 

 Aberjona and Charles Rivers in the New England Coastal Basins study area, 1998-2000 .............................. 41

Appendix 3. Volatile organic compounds analyzed in surface-water samples from the Aberjona 

 and Charles Rivers in the New England Coastal Basins study area, 1998-2000 .............................................. 42
Figures v

FIGURES

Figure 1. Map showing ecoregions and location of surface-water sampling sites, New England 

Coastal Basins study area ................................................................................................................... 3

Figure 2. Map showing land uses in the drainage basins of surface-water sampling sites in the 

New England Coastal Basins study area ............................................................................................. 5

Figure 3. Photograph showing cross-sectional view of the Neponset River, in Massachusetts, 

showing the water-quality sampling reach and the adjacent U.S. Geological Survey 

streamflow-gaging station on the right streambank ............................................................................ 6

Figure 4. Map showing location of the New England Coastal Basins (NECB) and Long IslandNew Jersey (LINJ) study areas and the sampling sites used to compare water-quality data 

between the study areas ....................................................................................................................... 10

Figure 5. Graph showing historical daily mean streamflow for the period of record (1940-2000), 

and daily mean streamflow and sample-collection streamflows for the 1998-2000 study 

period at the Aberjona River at Winchester, Mass. ............................................................................ 12

Figure 6. Graph showing distribution of specific conductance, pH, and dissolved oxygen, 

at the (A) six indicator and (B) three integrator sites in the New England Coastal 

Basins study area ................................................................................................................................. 13

Figure 7. Graph showing water temperature, concentration of dissolved oxygen (same scales), 

and instantaneous streamflow at the Aberjona River, Mass., 1998-2000 ........................................... 15

Figure 8. Graph showing distribution of calcium, sulfate, and chloride concentrations at the (A) six 

indicator and (B) three integrator sites in the New England Coastal Basins study area...................... 16

Figure 9. Graph showing distribution of total nitrogen, dissolved nitrate plus nitrite, and total 

ammonia plus organic nitrogen concentrations at the (A) six indicator and (B) three 

integrator sites in the New England Coastal Basins study area .......................................................... 18

Figure 10. Graph showing composition of total nitrogen concentrations in the (A) six indicator 

and (B) three integrator basins in the New England Coastal Basins study area ................................. 19

Figure 11. Graph showing distribution of instantaneous total nitrogen yields in the (A) six indicator 

and (B) three integrator sites in the New England Coastal Basins study area .................................... 19

Figure 12. Graph showing distribution of total phosphorus concentrations at the (A) six indicator 

and (B) three integrator sites in the New England Coastal Basins study area .................................... 20

Figure 13. Graph showing relation between concentrations of total phosphorus and suspended 

sediment for the six indicator sites and three integrator sites in the New England 

Coastal Basins study area ................................................................................................................... 21

Figure 14. Graph showing concentrations of volatile organic compounds detected in water samples 

in the (A) Aberjona and (B) Charles Rivers, Mass. ............................................................................ 24

Figure 15. Graph showing chloroform and methyl tert-butyl ether concentrations, and daily mean 

streamflow in the Aberjona River, Mass., from April 1999 to April 2000 ......................................... 25

Figure 16. Graph showing chloroform and methyl tert-butyl ether concentrations in the Charles River 

at Watertown, Mass., and daily mean streamflow at the Charles River at Waltham, Mass., 

from October 1998 to April 2000 ....................................................................................................... 25

Figure 17. Graph showing median total nitrogen (A) and median total phosphorus concentrations 

(B) of the New England Coastal Basins (NECB) fixed-site network in relation to the 

Long Island-New Jersey (LINJ) study area basins at Bound Brook at Middlesex and 

Passaic River at Two Bridges, N.J., and 76 urban rivers monitored by the National Water-Quality 

Assessment (NAWQA) Program throughout the Nation by indicator and integrator sites ................ 27
vi Figures

Figure 18. Graph showing median concentrations (A) and frequency of detection (B) of the pesticide 

compounds atrazine, prometon, carbaryl, and diazinon in the Aberjona River at Winchester, Mass., 

Bound Brook at Middlesex, N.J., Charles River at Watertown, Mass., and Passaic River at 

Two Bridges, N.J., in relation to 33 urban rivers monitored by the National Water Quality 

Assessment Program (NAWQA) throughout the Nation..................................................................... 28

Figure 19. Graph showing median concentrations (A) and frequency of detection (B) of the volatile 

organic compounds chloroform, cis-1,2, dichloroethene (cis-DCE), tetrachloroethylene 

(PCE), trichloroethylene (TCE), and methyl tert-butyl ether (MTBE) in the Aberjona 

River at Winchester, Mass., Bound Brook at Middlesex, N.J., Charles River at Watertown, 

Mass., and Passaic River at Two Bridges, N.J., in relation to 26 urban rivers monitored 

by the National Water Quality Assessment Program (NAWQA) throughout the Nation ................... 29
Tables vii

TABLES

Table 1. Characterization of fixed sampling sites in the New England Coastal Basins study area ................ 7

Table 2. Major water-quality issues of concern for the six indicator sites and three integrator sites 

in the New England Coastal Basins study area ................................................................................. 8

Table 3. Basin characteristics of the two Long Island-New Jersey Coastal Drainages NAWQA 

study unit monitoring sites in relation to New England Coastal Basins study unit monitoring 

sites ................................................................................................................................................... 11

Table 4. Summary statistics for selected water-quality constituents in the six indicator sites in 

the New England Coastal Basins study area, 1998-2000 ................................................................. 34

Table 5. Summary statistics for selected water-quality constituents in the three integrator sites in 

the New England Coastal Basins study area, 1998-2000 ................................................................. 38

Table 6. Relations between selected water-quality constituents and percent urban land use for the 

indicator and integrator sites in the New England Coastal Basins study area, 1998-2000................ 12

Table 7. Statistical summary of pesticide compounds detected in water samples from the 

Aberjona and Charles Rivers in the New England Coastal Basins study area, 1998-2000 .............. 22
viii Conversion Factors, Datum, and Abbreviations

CONVERSION FACTORS, DATUM, AND ABBREVIATIONS

Concentrations of chemical constituents in water are given in microsiemens per centimeter (μs/cm) at 25 degrees 

Celsius; milligram per liter (mg/L); microgram per liter (μg/L); nutrient loads are in kilogram per day (kg/d), and 

kilogram per day per square mile (kg/d/mi2).

Horizontal Datum: Horizontal coordinate information is referenced to the North American Datum of 

1927 (NAD 27).

Other abbreviations:

CCREM Canadian Council of Resources and Environmental Ministers

cis-DCE cis-1,2- dichloroethylene

DO Dissolved Oxygen

LINJ Long Island-New Jersey study unit

LRL Laboratory Reporting Level

MTBE Methyl tert-butyl ether

MCL Maximum Contaminant Level

NAWQA National Water-Quality Assessment Program

NECB New England Coastal Basins study unit

PCE Tetrachloroethylene

TCE Trichloroethylene

USEPA U.S. Environmental Protection Agency

USGS U.S. Geological Survey

VOC Volatile Organic Compound

Multiply By To obtain

inch (in.) 25.4 millimeter (mm)

inch (in.) 0.000254 micrometer (μm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

square mile (mi2) 2.590 square kilometer (km2)

cubic foot per second (ft3/s) 0.0283217 cubic meter per second (m3/s)
Abstract 1

ABSTRACT

Nine rivers were monitored routinely for a 

variety of field conditions, dissolved ions, and 

nutrients during 1998-2000 as part of the New 

England Coastal Basins (NECB) study of the

U.S. Geological Survey (USGS) National WaterQuality Assessment (NAWQA) Program. The 

nine rivers, located primarily in the Boston 

metropolitan area, represented a gradient of 

increasing urbanization from 1 to 68 percent urban 

land use. Additional water samples were collected 

and analyzed for pesticides and volatile organic 

compounds at two of the nine rivers. Specific 

conductance data from all rivers were correlated 

with urban land use; specific conductance values 

increased during winter at some sites indicating 

the effect of road de-icing applications. In the 

more intensely urbanized basins, concentrations of 

sodium and chloride were high during winter and 

likely are attributed to road de-icing applications. 

Concentrations of total nitrogen and the various 

inorganic and organic nitrogen species were 

correlated with the percentage of urban land in the 

drainage basin. Total phosphorus concentrations 

also were correlated with urbanization in the 

drainage basin, but only for rivers draining less 

than 50 square miles. Preliminary U.S. 

Environmental Protection Agency total nitrogen 

and total phosphorus criteria for the rivers in the 

area were frequently exceeded at many of the 

rivers sampled.

At the two sites monitored for pesticides and 

volatile organic compounds, the Aberjona and 

Charles Rivers near Boston, greater detection 

frequencies of pesticides were in samples from the 

spring and summer when pesticide usage was 

greatest. At both sites, herbicides were detected 

more commonly than insecticides. The herbicides 

prometon and atrazine and the insecticide diazinon 

were detected in over 50 percent of all samples 

collected from both rivers. No water samples 

contained pesticide concentrations exceeding any 

U.S. Environmental Protection Agency drinkingwater standard or criteria for protecting freshwater 

aquatic life. The volatile organic compounds 

trichloroethylene, tetrachloroethylene, and cis-1,2- 

dichloroethylene—all solvents and de-greasers—

were detected in all water samples from both 

rivers. The gasoline oxygenate methyl tert-butyl 

ether (MTBE) and the disinfection by-product 

chloroform were detected in all but one water 

sample from the two rivers. Two water samples 

from the Charles River had trichloroethylene 

concentrations that exceeded the U.S. 

Environmental Protection Agency Maximum 

Contaminant Level of 5 micrograms per liter for 

drinking water. 

Selected water-quality data from two NCEB 

rivers in the Boston metropolitan area were 

compared to two similarly sized intensely urban 

rivers in another NAWQA study area in the New 

York City metropolitan area and to other urban 

rivers sampled as part of the NAWQA Program 

nationally. Nutrient total nitrogen and total 

Water Quality of Selected Rivers in the New England 

Coastal Basins in Maine, Massachusetts, 

New Hampshire, and Rhode Island, 1998-2000

By Kimberly W. Campo, Sarah M. Flanagan, and Keith W. Robinson
2 Water Quality of Selected Rivers in the New England Coastal Basins, 1998-2000

phosphorus concentrations and yields were less in 

the NECB study area than in the other study areas. 

In addition, the pesticides atrazine, carbaryl, 

diazinon, and prometon were detected less 

frequently and at lower concentrations in the two 

NECB rivers than in the New York City area 

streams or in the other urban NAWQA streams. 

Concentrations of the insecticides diazinon and 

carbaryl were detected more frequently and at 

higher concentrations in the NECB study area than 

in the other urban rivers sampled by NAWQA 

nationally. Detection frequency and 

concentrations of volatile organic compounds 

generally were higher in the two NECB streams 

than in the New York City area streams or in other 

urban NAWQA streams.

INTRODUCTION

The National Water-Quality Assessment 

(NAWQA) Program was implemented in 1991 by the 

U.S. Geological Survey (USGS) to assess the status 

and trends in water quality for a large part of the 

Nation’s surface- and ground-water resources and to 

provide a better understanding of the factors that affect 

water quality (Gilliom and others, 1995). The New 

England Coastal Basins (NECB) study unit, 1 of 51 

study units across the Nation, began in 1997 as part of 

the NAWQA Program (Ayotte and Robinson, 1997).

A primary goal of the NAWQA Program is to 

characterize water-quality conditions of rivers on a 

local scale by monitoring selected rivers in NAWQA 

study units. Monitoring is performed routinely at a 

group of river locations, which is called a fixed-site 

network (Gilliom and others, 1995). Because 

urbanization is important to local water-resource 

managers in the NECB study unit (termed study area 

throughout the remainder of the report) and the 

NAWQA Program (Ayotte and Robinson, 1997), the 

NECB study incorporated urbanization and its effects 

on stream-water quality in the design of the NECB 

fixed-site network. The NECB fixed-site network 

contained nine rivers; the selection of these rivers for 

inclusion in the fixed-site network was based primarily 

on the extent of urbanization in the drainage basin. 

Surface-water samples were collected monthly or more 

frequently from 1998 to 2000 to assess the spatial and 

temporal variability of chemical concentrations and 

loads in relation to hydrologic conditions and drainagebasin characteristics. 

Purpose and Scope

This report summarizes the results of surfacewater-quality monitoring conducted for the NECB 

fixed-site network from October 1998 to September 

2000. Data from 27 to 76 water samples collected at 

each site for field measurements, dissolved ions, 

nutrients, pesticides, and volatile organic compounds 

(VOCs) are included. The effects of urbanization on 

measurements, concentrations, loads, and yields of 

selected constituents are described, as are seasonal and 

hydrologic trends. Finally, water-quality data from two 

urban rivers in the study area are compared to waterquality data from two urban basins in another NAWQA 

study unit in the New York City area, and to waterquality data from urban basins nationwide.

Description of the New England Coastal Basins 

Study Area

The NECB study area encompasses 23,000 mi2

in western and central Maine, central and eastern New 

Hampshire, eastern Massachusetts, most of Rhode 

Island, and a small part of eastern Connecticut (fig. 1). 

The study area includes the major drainage basins of 

the Kennebec, Merrimack, Androscoggin, Saco, 

Charles, and Blackstone Rivers, as well as many small 

coastal drainage basins between these major basins. 

The study area had an estimated population of

8.3 million persons in 2000, an increase of 6.8 percent 

since 1990 (Kerie Hitt, U.S. Geological Survey, written 

commun., 2002). The highest population densities 

were in the southern and coastal regions of the study 

area. Major metropolitan areas include Boston, Mass., 

and Providence, R.I. The study area includes parts of 

four U.S. Environmental Protection Agency (USEPA) 

ecoregions: the Atlantic Coastal Pine Barrens, 

Laurentian Plains and Hills, Northeastern Coastal 

Zone, and the Northeastern Highlands (Omernick, 

1987) (fig. 1). Land use in the 1990s (Vogelmann and 

others, 2001) was estimated to be 75-percent forested, 

11-percent urban, 6-percent agriculture, 5-percent
Introduction 3

EXPLANATION

Ecoregions

 Northeastern Highlands

 Northeastern Coastal Zone

 Atlantic Coastal Pine Barrens

 Laurentian Plains And Hills

 New England Coastal Basins 

 boundary

 Capital city

 City

 U.S. Geological Survey stream-gaging site 

 associated with nearby water-quality 

 sampling site

Fixed-site network

 Indicator site

 Streamflow and water-quality data

 Integrator site

 Streamflow and water-quality data

 Water-quality data only

River sampled

 1 Aberjona 6 Neponset

 2 Ipswich 7 Charles

 3 Wading 8 Kennebec

 4 Saugus 9 Merrimack

 5 Stillwater

0 25 50 MILES

0 25 50 KILOMETERS

Merrimack

R.

Kennebec R.

Saco R.

Androsco g gin R.

2

5

9

4

1

7

3

Massachusetts

New

Hampshire

Maine

8

Atlantic

Ocean

Boston

Portland

Augusta

72o

71o

70o

42o

44o

0

0

50 MILES

50 KILOMETERS

68 ̊

New

Hampshire

Massachusetts

Connecticut

Rhode

Island

Vermont

CANADA

Maine

New England

 Coastal Basins

 study area

70 ̊

46 ̊

72 ̊

44 ̊

42 ̊

Rhode

Island

Providence

Manchester

6

Base from U.S. Geological Survey 

Digital data, 1:2,000,000, 1972;

Ecoregions from Omernik, J.M., 1987

Connecticut

Blackstone R.

Moosehead

Lake

Long Island Sound

Flagstaff

Lake

Mooselookmeguntic

Lake

Sebago

Lake

Lake

Winnipesaukee

Neponset R.

Nashua R.

Charles R.

Figure 1. Ecoregions and location of surface-water sampling sites, New England Coastal Basins study area.
4 Water Quality of Selected Rivers in the New England Coastal Basins, 1998-2000

surface-water bodies, and 3-percent other land uses 

(Vogelmann and others, 2001); (Flanagan and others, 

1999) (fig. 2). 

Most of the NECB study area is underlain by 

near-surface bedrock, which controls the natural 

surface-water quality. Weather-resistant igneous and 

metamorphic rock plus thin, compact soils result in 

surface waters that naturally contain low 

concentrations of nutrients, dissolved and suspended 

solids, and are highly susceptible to acidification by 

precipitation. A more detailed description of the 

NECB study area and the environmental settings are 

presented in Flanagan and others (1999).

Human activities have effected surface-water 

quality in the study area. For more than 200 years, the 

damming of rivers and the disposal of untreated wastes 

from pulp and paper mills, lumber mills, textile and 

tanning factories, and urban populations made some 

rivers in New England among the most contaminated in 

the United States (Flanagan and others, 1999). 

Surface-water quality in New England began 

improving in the 1970s with the passage of the Clean 

Water Act of 1972 (U.S. Environmental Protection 

Agency, 2002a). As a result of the Clean Water Act, 

increased Federal, State, and local funds were spent to 

construct municipal wastewater-treatment plants. 

Many private industries also constructed facilities to 

treat their waste by-products. Consequently, many 

rivers that were once severely contaminated may now 

be clean enough for swimming and fishing. 

Despite improvements described above, a 

number of water-quality issues remain. In its 2000 

State of the New England Environment Report, the 

USEPA has identified high nutrient loads as the biggest 

water-quality issue for many New England waterways 

in the 1990s (U.S. Environmental Protection Agency, 

2000a). The USEPA considers excessive amounts of 

phosphorus to be the leading cause of eutrophication in 

most New England lakes and streams, and excessive 

amounts of nitrogen to be the leading cause of 

eutrophication in estuaries and coastal areas such as 

Long Island Sound. Bottom sediments in many 

surface-water bodies continue to show contamination 

from nutrients, polychlorinated biphenyls (PCBs), 

mercury, and other heavy metals deposited from past 

and present human activities (Chalmers, 2002). The 

expansion of urban and suburban development 

throughout the study area is resulting in additional 

urban stormwater discharges. Acidic atmospheric

deposition, composed of sulfur dioxide and nitrogen 

oxide, negatively affects lakes and forests, particularly 

in northern New England (Flanagan and others, 1999). 

Other major causes of water-quality impairment in 

New England waters in the 1990s were from 

waterborne pathogens, mercury contamination of 

freshwater fishes, and low dissolved oxygen (U.S. 

Environmental Protection Agency, 2000a).

Flow alteration has affected some small drainage 

basins, where water withdrawals from surface and 

ground waters for drinking-water use or irrigation have 

resulted in reduced streamflows during parts of the year 

(Flanagan and others, 1999). For example, during 

those periods of extreme low-flow conditions, nutrientrich wastewater effluent can be most of the streamflow 

in small river basins if municipal wastewater-treatment 

facilities are present. 

Excessive algae growth, shown as a plume forming behind a dam on 

the Nashua River, Mass., commonly is the result of high nutrient loads 

in surface waters.
Introduction 5

6

3

5

Manchester

Massachusetts

Rhode Island

72o

70o

44o

8

0 5 10 MILES0 5 10 KILOMETERS

0 25 50 MILES0 25 50 KILOMETERS

AtlanticOcean Boston

Augusta

Providence

42o

Base from U.S. Geological Survey digital data, 1:2,000,000, 1972;U.S. Environmental Protection Agency satellite imagery, 30-meter-pixel resolution, National land cover dataset, 1992

Providence

EXPLANATION

LAND USE Watershed boundary  Water River   Urban NECB boundary   Barren State boundary   Forest Indicator site, streamflow  and water-quality data  Agriculture  Integrator site, streamflow Wetland and water-quality data Water-quality data only

Bos

Worcester

Lowell

9

1

7

Figure 2. Land uses in the drainage basins of surface-water sampling sites in the New England Coastal Basins study area.
6 Water Quality of Selected Rivers in the New England Coastal Basins, 1998-2000

Acknowledgments

Special thanks to Karen Beaulieu and Britt Stock 

of the U.S. Geological Survey for the long hours they 

spent collecting and processing samples. James Coles 

and Marc Zimmerman of the U.S. Geological Survey 

were instrumental in planning and designing the NECB 

fixed-site network.

STUDY DESIGN

The nine rivers monitored for water quality 

represent a mixture of small (indicator) and large 

(integrator) basins and different land uses (table 1). 

Indicator basins are less than 100 mi2 in size and are 

selected on the basis of a particular land use or 

environmental setting (Gilliom and others, 1995). 

Integrator basins are greater than 250 mi2 in size and 

are selected to document water-quality conditions in 

heterogeneous large drainage basins that are affected 

by different land uses and environmental settings. 

Site-selection criteria for all rivers include the 

presence of a continuous-recording, streamflow-gaging 

station maintained by the USGS at or near the waterquality sampling site (fig. 3). Site-selection criteria for 

indicator basins included

• The location of the stream in one similar 

ecoregion as defined by Omernik (1987) to 

minimize the effects of natural factors (such 

as climate, topography, vegetation, and soils) 

on water quality. All six selected indicator 

drainage basins are in the Northeastern 

Coastal Zone ecoregion (fig. 1). 

• The physical characteristics of the sampling 

reach had to meet NAWQA criteria for the 

biological assessments of habitat, fish, algae, 

and macroinvertebrates (Gilliom and others, 

1995). These criteria require the presence of 

riffle, run, and pool habitats in the sampling 

reach.

• Minimal effects on water quality and 

streamflow from known point sources of 

wastewater (permitted municipal and 

industrial wastewater-treatment facility 

discharges).

The nine sites were sampled monthly. 

Additional samples were collected during low and high 

flows. Two sites, one indicator and one integrator, 

were selected for intensive sampling, which involved 

more frequent sample collection at weekly or biweekly intervals. The intensive sampling strategy was 

designed to assess the occurrence and seasonal patterns 

in concentrations of pesticides and VOCs. The most 

urban indicator and integrator sites, the Aberjona and 

Charles Rivers, respectively, were selected for intensive 

sampling.

Indicator Basins

The primary objective of sampling in the six 

indicator basins was to describe how water quality 

varies along a gradient of urban intensity. The six 

indicator basins, the Aberjona, Ipswich, Neponset, 

Saugus, Stillwater, and Wading Rivers, are all in 

eastern Massachusetts and were selected to assess the 

affects of urbanization on the water quality of similarsized drainage basins in the Northeastern Coastal Zone 

ecoregion (figs. 1 and 2, table 1). Urban land use 

ranges from 4 percent in the Stillwater River Basin to 

68 percent in the Aberjona River Basin. Drainage areas 

range from 23 to 45 mi2 (table 1). Each indicator basin 

was classified either as minimally urbanized (urban 

land use comprised less than 5 percent of the drainage 

basin), moderately urbanized (urban land use greater 

than 5 and less than 50 percent), or intensely urbanized

Figure 3. Cross-sectional view of the Neponset River, in 

Massachusetts, showing the water-quality sampling reach and the 

adjacent U.S. Geological Survey streamflow-gaging station on the right 

streambank.
Study Design 7

Table 1. Characterization of fixed sampling sites in the New England Coastal Basins study area

[No., number; fig., figure; STAID, Station identifier number; mi2, square miles; Urb, urban; Ag, agriculture; For, Forest; Wet, wetlands; Wat, water;

°, degree, ′, minute, ′′, second; INT, intensive fixed site; BAS, basic fixed site]

Site 

No.

(fig. 1)

Site name STAID Latitude Longitude Sample 

type

Basin 

size 

(mi2)

Land use/Land cover 12000 

Population 

density

(people/mi2)

1Data from Kerie Hitt, U.S. Geological Survey, written commun., 2003.

Level of 

urbanization Urb Ag For Wet Wat

(percent of total)

Indicator sites

1 Aberjona River at 

Winchester, 

Mass.

 01102500 42° 26′ 50′′ 71° 08′ 22′′ INT 25 68 2 24 4 2 2,973 Intensely 

urbanized

2 Ipswich River at 

South Middleton, 

Mass.

 01101500 42° 34′ 10′′ 71° 01' 39′′ BAS 45 38 4 40 16 2 1,191 Moderately 

urbanized

3 Neponset River at 

Norwood, Mass.

 01105000 42° 10′ 39′′ 71° 12′ 05′′ BAS 35 30 6 53 10 1 1,093 Moderately 

urbanized

4 Saugus River at 

Saugus Iron 

Works at Saugus, 

Mass.

 01102345 42° 28′ 10′′ 71° 00′ 28′′ BAS 23 56 4 27 9 4 2,340 Intensely 

urbanized

5 Stillwater River 

near Sterling, 

Mass.

 01095220 42° 24′ 39′′ 71° 47′ 30′′ BAS 32 4 10 76 8 2 203 Minimally 

urbanized

6 Wading River near 

Norton, Mass.

 01109000 41° 56′ 51′′ 71° 10′ 38′′ BAS 43 18 7 64 10 1 597 Moderately 

urbanized

Integrator sites

7 Charles River above 

Watertown Dam 

at Watertown, 

Mass.

 01104615 42° 21′ 54′′ 71° 11′ 26′′ INT 268 30 7 53 7 3 1,460 Moderately 

urbanized

8 Kennebec River at 

North Sidney, 

Maine

 01049265 44° 28′ 25′′ 69° 41′ 08′′ BAS 5,403 1 6 83 4 6 26 Minimally 

urbanized

9 Merrimack River 

below Concord 

River at Lowell, 

Mass.

 01100000 42° 38′ 45′′ 71° 17′ 56′′ BAS 4,635 9 8 74 5 4 308 Moderately 

urbanized
8 Water Quality of Selected Rivers in the New England Coastal Basins, 1998-2000

(urban land use greater than 50 percent) (table 1). 

Major water-quality issues in each of the indicator 

basins are summarized in table 2. 

Integrator Basins

The three integrator basins in the NECB fixedsite network include the Charles, Kennebec, and 

Merrimack Rivers (fig. 1, table 1). The Merrimack and 

Kennebec Rivers are the two largest rivers, covering

44 percent of the study area. These two rivers share a 

similar water-quality history. In both drainage basins, 

dams to generate hydropower were constructed in the 

19th and early 20th centuries and soon were followed 

by settlement and industrialization (Davies and others, 

1999). The rivers and their major tributaries became 

severely contaminated by the middle to late 1800s and 

remained that way for the next century. Currently 

(2003), after two centuries of extensive deforestation, 

forests are once again the predominant land cover in 

both drainage basins (table 1). The Merrimack River 

drains various large metropolitan cites, whereas the 

Kennebec River drains small cities. The Charles River

Table 2. Major water-quality issues of concern for the six indicator sites and three integrator sites in the New England Coastal Basins study area

[USEPA, U.S. Environmental Protection Agency; CSOs, combined sewer overflows; oC, degrees Celsius] 

River name Water-quality issue of concern reported to the USEPA as required in section 303(d) of the Clean Water Act1

1 U.S. Environmental Protection Agency, 2002a.

Indicator rivers

Aberjona Elevated levels of waterborne pathogens, non-ionized ammonia, nutrient enrichment, and low dissolved oxygen.2

2 M.J. Weinstein, Massachusetts Department of Environmental Protection, Division of Watershed Management, written commun., 2002.

Ipswich Nutrients, waterborne pathogens, organic enrichment, and low dissolved oxygen. Excessive withdrawals of ground water in 

upper parts of watershed results in extremely low streamflows during summer and fall months, which threatens aquatic 

life in the stream.3, 4

3 DeCesare and others, 2000.

4 Zarriello, 2002.

Neponset Priority organics, metals, siltation, nutrient enrichment, low dissolved oxygen, waterborne pathogens, suspended solids, 

noxious aquatic plants, turbidity, and water temperatures exceeding 20 oC.2

Saugus Nutrients, such as nitrogen-ammonia and total phosphorus, low dissolved oxygen, elevated levels of specific conductance, 

and water temperatures exceeding 20 oC.3

Stillwater pH values below 6.5 and water temperatures exceeding 20 oC.5 This river is one of two main tributaries to Wachusetts 

Reservoir, a source of public water supply.

5 Weinstein and others, 2001.

Wading Nutrient enrichment, low dissolved oxygen, and bacterial and viral pathogens. Effluent from two wastewater-treatment 

plants exceeded surface-water criteria for trace metals aluminum, copper, lead, and zinc.6

6 Massachusetts Department of Environmental Protection, written commun., 1996.

Integrator rivers

Charles Nutrient enrichment from wastewater discharges and stormwater runoff.7 Streambed sediment quality in lower half of basin 

is severely degraded.8

7 Fiorentino and others, 2000.

8 Breault and others, 2000.

Kennebec Basin contains numerous eutrophic lakes and tributaries.9 Discharges from CSOs, inadequate sewers, and aging 

wastewater-treatment facilities.10 Streamflow is highly regulated.

9 Davies and others, 1999.

10 Maine Department of Environmental Protection, 2000.

Merrimack Pathogens derived mostly from CSOs in cities and nutrient enrichment.11 Streamflow is moderately to highly regulated.

11 Kennedy and others, 2001.
Data Collection and Analysis 9

Basin is much smaller in size than the Merrimack and 

Kennebec River Basins, but was selected because it is 

the dominant drainage basin in the Boston metropolitan 

area in eastern Massachusetts. Major water-quality 

issues of concern in each of the integrator basins are 

summarized in table 2.

DATA COLLECTION AND ANALYSIS

All nine sites were monitored using NAWQA 

fixed-site sampling protocols that are consistent among 

all NAWQA sampling activities throughout the Nation. 

Various graphical and statistical methods were used to 

analyze water-quality data. 

Data Collection

NAWQA protocols for fixed-site sampling are 

designed to assess the spatial and temporal distribution 

of water quality in relation to various streamflow 

conditions and consist of water-quality sample 

collection at each fixed site monthly or more frequently 

(Gilliom and others, 1995). Water samples collected at 

all fixed sites were analyzed for dissolved ions, 

nutrients, dissolved and suspended organic carbon, and 

suspended sediment (see appendix 1 for a complete list 

of all analyzed constituents). Field measurements of 

specific conductance, pH, water temperature, dissolved 

oxygen (DO), alkalinity, and bicarbonate were made 

onsite at the time of sample collection. All field 

measurements were completed according to NAWQA 

protocols (Shelton, 1994; Wilde and Radte, 1998). 

Instantaneous discharge was obtained from 

continuous-recording, streamflow-gaging stations at or 

near each site, maintained by USGS personnel in 

accordance with standard USGS procedures (Rantz and 

others, 1982). 

NAWQA intensive fixed-site sampling protocols 

include more frequent sampling (weekly and biweekly) and the collection of samples for determining 

the occurrence and seasonal patterns of pesticides and 

VOCs. Water samples analyzed for pesticides were 

collected throughout the year (weekly for the Aberjona 

River from April 1999 through September 2000, and 

bi-weekly for the Charles River from May 1999 

through March 2000). Samples analyzed for VOCs 

were collected throughout the year, although sample 

collection frequency ranged from monthly during April 

to November to weekly or bi-weekly during December 

to March. The more frequent sampling for VOCs was 

done during the winter when VOC detections is 

expected to be high because of cold temperatures 

(Lopes and Price, 1997). 

Most surface-water samples were obtained by 

collecting depth-integrated subsamples at equal-width 

increments across the stream channel by wading, or 

from bridges or cableways, using a US DH-81 or

US D-77 sampler (Shelton, 1994). During low flows 

and extreme high flows, a midpoint-depth integrated or 

grab sample was collected at the indicator sites. A 

weighted-bottle sampler was used separately to collect 

dissolved and suspended organic-carbon samples in a 

baked amber glass bottle at the midpoint in the stream. 

Water samples for VOC analysis were collected with a 

specially designed Wildco sampler at the midpoint in 

the river channel (Shelton, 1997). 

Water samples were processed in the field 

according to NAWQA protocols (Shelton, 1994). A 

cone splitter was used to composite most of the 

samples into Teflon bottles. Samples analyzed for 

dissolved ions, nutrients, and field alkalinity were 

filtered through a 0.45-μm pore-size capsule filter, 

samples analyzed for dissolved and suspended organic 

carbon were filtered through a 0.45-μm pore-size silver 

filter, and samples analyzed for pesticides were filtered 

through a 0.7-μm pore-size glass-fiber filter. 

Suspended-sediment samples were collected and 

processed according to methods described by Edwards 

and Glysson (1988) and shipped to the USGS Sediment 

Laboratory in Louisville, Ky., for particle-size and 

concentration analysis. All other water-quality 

samples were shipped to the USGS National WaterQuality Laboratory (NWQL) in Denver, Colo., for 

analysis. Individual results for each water-quality 

constituent are published in selected USGS water-data 

reports (Socolow and others, 2000, 2001; Nielsen and 

others, 2000; Stewart and others, 2001).

Data Analysis

The StatView (SAS Institute, Inc., 1999) 

statistical software package was used for all statistical 

analysis. Nonparametric statistics were used on the 

assumption that the data were not normally distributed. 

Spearman rank-correlation analysis was used to 

compare water-quality data to urbanization in each 

drainage basin using the median concentration values 
10 Water Quality of Selected Rivers in the New England Coastal Basins, 1998-2000

and the percentage of upstream urban land use. For 

this report, data were considered statistically correlated 

when rho values (the Spearman rank correlation 

coefficient) were equal to or greater than 0.40 and 

probability (p) was less than 0.05. The Kruskal-Wallis 

test was used to test for significant differences in 

median values among sites by performing a one-way 

analysis of variance on the ranks of the data. The 

Tukey-Kramer (or Tukey’s HSD) multiple comparison 

test (Helsel and Hirsch, 1992) on rank-transformed 

data then was used to examine differences among sites 

if the Kruskal-Wallis results showed significant 

differences.

Data distributions of selected constituents for 

each site and among sites were displayed with boxplots 

(Helsel and Hirsch, 1992). The results of the multiple 

comparison tests are displayed as letters placed above 

the boxplots for each site to indicate significant 

groupings. The letter “A” is designated to the site(s) 

with the highest median concentration, and subsequent 

letters are assigned to sites with correspondingly lower 

median concentrations. More than one letter is 

designated to a site if the significant groupings overlap. 

For example, if three sites are assigned letters “A”, 

“AB”, and “B”, respectively, sites A and B are 

significantly different, but site AB is not significantly 

different from either site A or site B.

In this report, total nitrogen is the sum of 

dissolved nitrite plus nitrate (NO2+NO3) and total 

ammonia (NH3) plus organic nitrogen. Instantaneous 

discharge, concentration, and a conversion factor were 

used to calculate instantaneous loads for total nitrogen 

and total phosphorus, in kilograms per day. 

Instantaneous loads were calculated based on the 

general assumption that the instantaneous discharge 

and concentration were constant for that day, and, 

therefore, are reported in kilograms per day. 

Instantaneous loads for total nitrogen and total 

phosphorus for each site were divided by the respective 

basin drainage area to calculate instantaneous yields, in 

kilograms per day per square mile.

Qualitative comparisons of water-quality data 

from NECB monitoring sites in the Boston 

metropolitan area to data from monitoring sites in the 

New York City metropolitan area (fig. 4) and to 

national NAWQA results were done to determine the 

similarity of data from various urban areas throughout 

the Nation. Total nitrogen and total phosphorus data 

from the NECB monitoring sites were compared to 

data from two monitoring sites in the Long Island-New 

Jersey Coastal Drainages (LINJ) study unit and to other 

urban indicator and integrator sites monitored by the 

NAWQA Program to determine differences in median 

total nitrogen and total phosphorus concentrations on a 

regional and national scale. In addition, data for the 

most frequently detected pesticide and VOC 

compounds found in samples from the two NECB 

monitoring sites (Aberjona and Charles Rivers) were 

compared to the LINJ study results and to other urban 

sites in the NAWQA Program to determine differences 

in the occurrence and concentrations of the selected 

pesticides and VOCs on a regional and national scale. 

The LINJ sites included in the regional 

comparison were Bound Brook at Middlesex, N.J. 

(urban indicator basin; station identification (ID) 

number 01403900) and Passaic River at Two Bridges, 

N.J. (integrator basin; station ID number 01382000) 

(Edward Pustay, U.S. Geological Survey, written 

commun., 2002) (fig. 4). Water-quality data from these 

two streams were collected from 1996 to 1998. The 

two LINJ monitoring sites have similar basin sizes and 

land uses compared to the two NECB monitoring sites 

(table 3). 

For the national comparison, nutrient waterquality data were collected from more than 2,700 water 

samples in 48 urban indicator and 28 urban integrator 

sites monitored by the NAWQA Program during

EXPLANATION

 National Water Quality 

 Assessment Program 

 study area

 Drainage basin for 

 sampling site

 Sampling site and 

 number

Base from U.S. Geological Survey

Digital data, 1:2,000,000, 1972

Boston

New York City

40o

42o

0 50 MILES

0 50 KILOMETERS

New York Connecticut Rhode

Island

01382000

New Jersey

Massachusetts

01102500

01104615

01382000

01403900

Atlantic Ocean

LINJ

study area

NECB

study area

74o 72o

Figure 4. Location of the New England Coastal Basins (NECB) and Long 

Island-New Jersey (LINJ) study areas and the sampling sites used to 

compare water-quality data between the study areas. (Sampling sites in 

the LINJ study area are described in table 3)
Water Quality of Selected New England Coastal Basins Rivers 11

1992-2000 (David Mueller, U.S. Geological Survey, 

written commun., 2003). Pesticide water-quality data 

were collected from more than 850 samples in 33 urban 

sites in the NAWQA Program during the same period 

(Jeffrey D. Martin, U.S. Geological Survey, written 

commun., 2003); data accessed on March 13, 2003, at 

http://ca.water.usgs.gov/pnsp/pestsw/Pest-SW_2001

_Text.html. VOC water-quality data were collected 

from 711 samples in 26 urban sites in the NAWQA 

Program during 1996-2000; data accessed on May 16, 

2003, at http://sd.water.usgs.gov/usgs/vocns/ifs-55-

vocs-summary.xls.

WATER QUALITY OF SELECTED NEW 

ENGLAND COASTAL BASINS RIVERS

Summary statistics for selected water-quality 

field measurements and constituents analyzed for each 

site are presented in tables 4 and 5 (back of report), and 

discussed in the following sections. The relations of 

the results from the nine fixed sites to the percent of 

urban land use in the drainage basin and the relations 

among the groups of indicator and integrator sites are 

presented in table 6. Streamflow conditions at the 

fixed sites during the 1999 and 2000 water years1 are 

described briefly and compared to historical mean 

streamflows. 

Streamflow Conditions

Streamflow often affects the water-quality 

conditions of a stream. During high flow, 

concentrations of some water-quality constituents may 

decrease as a result of dilution, or increase as a result of 

inputs from stormwater runoff. A hydrograph showing 

the daily mean streamflow for the sampling period, an 

overlay of historical range of daily mean streamflow 

(based on 1940-2000 period of record), and the 

sampling dates for the Aberjona River at Winchester, 

Mass.—one of the nine fixed sites—is presented in 

figure 5. Generally, streamflow in the nine fixed sites 

during the study period was below normal during the 

spring and summer (April to August) in water year 

1999 (Socolow and others, 2000; Nielsen and others, 

2000) and normal to above normal throughout water 

year 2000 (Socolow and others, 2001; Stewart and 

others, 2001) when compared to historical means of 

long-term (1940-2000) discharge. For example, 

streamflow at the Aberjona River at Winchester, Mass., 

during the spring and summer in water year 1999 fell 

below the 25th percentile of historical daily mean 

streamflow (fig. 5). 

Field Measurements

Specific conductance is a measure of the ability 

of a substance to conduct an electrical currant, and is 

an indicator of the concentrations of dissolved ions or 

solids in solution. Median specific conductance values 

ranged from 105 (Stillwater River) to 521 μs/cm at 

25°C (Aberjona River) in the six indicator rivers and 

from 67.5 (Kennebec River) to 326 μs/cm at 25°C 

(Charles River) in the three integrator rivers (tables 4 

and 5, fig. 6). For both the indicator and integrator 

basins, specific-conductance values were correlated 

with urbanization (table 6), with higher specific 

conductance values measured at sites with higher 

percentages of urban land use than at sites with lower 

percentages of urban land use in the drainage basin 

(fig. 6). 

Generally, samples collected during the summer, 

when streamflows were lowest, had higher specificconductance values than samples collected during the 

winter. Specific conductance decreased as streamflow

1A water year begins on the first day of October and ends on the 

last day of September the following year. For example, the 1999 

water year includes October 1, 1998, through September 30, 1999.

Table 3. Basin characteristics of the two Long Island-New Jersey 

Coastal Drainages NAWQA study unit monitoring sites in relation 

to New England Coastal Basins study unit monitoring sites

[USGS, U.S. Geological Survey; No., number; mi2, square miles; Source: 

Reiser and O’Brien, 1998]

Site USGS site 

No.

Drainage 

area 

(mi2)

Land use 

(in percent)

Urban Forest Agriculture

Passaic River at 

Two Bridges, N.J.

01382000 361 47 35 3

Bound Brook at 

Middlesex, N.J.

01403900 48.4 68 25 1
12 Water Quality of Selected Rivers in the New England Coastal Basins, 1998-2000

.

Table 6. Relations between selected water-quality constituents and percent urban land use for the indicator and integrator 

sites in the New England Coastal Basins study area, 1998-2000

[Spearman's rank correlation coefficients (rho) and probability values (p-values) are significant (in bold) when rho is greater 

than 0.5, and p-values are less than 0.005; <, less than; negative values indicate an inverse relation]

Water-quality constituent

Percent urban land use

Indicator Integrator

rho p-value rho p-value

Specific conductance 0.85 <0.0001 0.92 <0.0001

Field pH .60 <.0001 .093 .513

Dissolved oxygen -.19 .0061 -.159 .1133

Calcium .89 <.0001 .87 <.0001

Sulfate .83 <.0001 .73 <.0001

Chloride .81 <.0001 .92 <.0001

Ammonia .78 <.0001 .42 <.0001

Ammonia + organic, dissolved .79 <.0001 .73 <.0001

Ammonia + organic, total .82 <.0001 .75 <.0001

Nitrite .75 <.0001 .43 <.0001

Nitrite + nitrate .85 <.0001 .78 <.0001

Nitrogen, total .92 <.0001 .83 <.0001

Phosphorus, dissolved -.04 .6173 -.00008 .9994

Phosphorus, ortho .09 .1889 -.14 .1682

Phosphorus, total .40 <.0001 .28 .0078

Total nitrogen, Yield .43 <.0001 .40 <.0001

Total phosphorus, Yield .13 .0793 .14 .186

EXPLANATION

 75th percentile (1940-2000 water years)

 25th percentile (1940-2000 water years)

 Mean daily streamflow

 Instantaneous streamflow at time of sample

OND

1999

J F MA MJ J A S OND

2000

J F MA MJ J A S

STUDY PERIOD, IN MONTHS

0.1

1

10

100

1000

Aberjona River

STREAMFLOW, 

IN CUBIC FEET PER SECOND

1998

Figure 5. Historical daily mean streamflow for the period of record (1940-2000), and daily mean streamflow and samplecollection streamflows for the 1998-2000 study period at the Aberjona River at Winchester, Mass.
Water Quality of Selected New England Coastal Basins Rivers 13

EXPLANATION

 Data for sites that have the same letter designation 

 do not differ significantly at the alpha=0.05 level

 Number of samples

 Highest value

 75th percentile

 50th percentile (median)

 25th percentile

 Lowest value

 Percent urban land use upstream of the sampling site

0

5

10

15

20

(75)

(29)

(27) (27) (26)

(29) (50) (24) (26)

DISSOLVED OXYGEN, 

IN MILLIGRAMS PER LITER

0

5

10

15

20

0

500

1,000

(75)

(29) (27)

(27)

(27)

(29)

(51)

(24)

(26)

A

B

C D CD

E

1,010

A

B

C

SPECIFIC CONDUCTANCE,

IN MICROSIEMENS PER METER

AT 25 DEGREES CELSIUS

0

500

1,000

6

7

8

(41)

(16)

(11)

(15)

(13)

(13)

(12) (26)

(12)

A A

B

A

B

B

A

B

A

pH, IN STANDARD

pH UNITS

6

7

8

A. Indicator sites B. Integrator sites

Stillwater Wading Neponset Ipswich Saugus Aberjona

(27)

Kennebec Merrimack Charles

A

[4] [18] [30] [38] [56] [68] [1] [9] [30]

[4]

RIVER

Figure 6. Distribution of specific conductance, pH, and dissolved oxygen, at the (A) six indicator and (B) three integrator sites in the New 

England Coastal Basins study area. (Location of sites shown in fig. 1.)
14 Water Quality of Selected Rivers in the New England Coastal Basins, 1998-2000

increased during storms because of dilution. At two of 

the more urban indicator sites (Aberjona and Ipswich 

Rivers), samples collected during the winter and early 

spring had greater specific conductance values than 

samples collected during summer and fall, possibly 

because of road de-icing applications. This result was 

most apparent in the Aberjona River, where specific 

conductance values exceeded 800 μs/cm at 25°C in 

water samples from winter and early spring.

The pH of water is a measure of the hydrogen 

ion concentration (acidity) in the water. The pH of 

water directly affects the physiological functions of 

plants and animals, and is an important indicator of the 

health of aquatic ecosystems. On the pH scale, 7 is 

neutral, less than 7 is acidic, and greater than 7 is 

alkaline. Median pH values in all nine basins 

consistently were around 7 (tables 4 and 5, fig. 6). The 

pH values from the indicator basins correlated with 

urbanization, with high pH values measured at sites 

with high percentages of urban land use. Measured pH 

values for the integrator basins did not correlate with 

the percentage of urban land use in the drainage basin 

(table 6). Multiple comparison tests on pH data from 

the indicator sites showed two significant groups: the 

Stillwater, Ipswich, and Wading Rivers had median pH 

values that were lower than the pH in the other rivers 

and slightly acidic; the other three sites had slightly 

alkaline median pH values (fig. 6). Seventy percent

(9 of 13) of the pH values for the Stillwater River were 

less than or equal to the State of Massachusetts 

minimum criteria of 6.5 for Class A surface waters 

(Massachusetts Department of Environmental 

Protection, 1996); these low pH values are thought to 

be caused by natural factors such as soils, vegetation, 

and the geology of glacial sediments and near-surface 

bedrock.

Adequate dissolved oxygen (DO) concentrations 

in water are necessary for the survival and growth of 

most aquatic organisms. The State of Massachusetts 

requires that surface waters contain a minimum of 5.0 

to 6.0 mg/L of DO to protect warm- and cold-water 

fisheries, respectively (Massachusetts Department of 

Environmental Protection, 1996). Median 

concentrations of DO measured at the six indicator 

sites ranged from 8.0 (Aberjona River) to 10.5 mg/L 

(Saugus River) (table 4, fig. 6). In the three integrator 

sites, median concentrations of DO ranged from

9.2 mg/L (Charles River) to 11.3 mg/L (Kennebec 

River) (table 5, fig. 6).

Another measure of DO in water is DO 

saturation. DO saturation is the percentage of the 

measured DO concentration in water compared to the 

saturated amount of DO in water at a given water 

temperature and barometric pressure. Median DO 

saturations ranged from 79 (Aberjona River) to

93 percent (Neponset River) (table 4) at the six 

indicator basins, and ranged from 87 (Charles River) to 

98 percent (Kennebec River) at the three integrator 

sites (table 5).

DO concentrations at the indicator and integrator 

sites were not correlated with the percentage of urban 

land in the drainage basin (table 6). Various field DO 

measurements in the Aberjona, Merrimack, and 

Charles Rivers were below the Massachusetts 

minimum criteria of 5 mg/L for Class B surface waters. 

Concentrations of DO in 15 percent of water samples 

(11 of 75) collected in the Aberjona River were below 

the 5 mg/L criteria; 10 of these water samples were 

collected from May through August 1999 during a 

period of reduced streamflows (fig. 7). The lowest DO 

concentration and saturation value measured in the 

Aberjona River during that time were 3.2 mg/L and

35 percent, respectively. In the same time period, DO 

concentrations were measured below 5 mg/L in the 

Merrimack River once and in Charles Rivers at seven 

sampling events; the lowest DO saturation measured at 

both sites was 26 percent. At all nine sites, samples 

collected during the winter had higher DO 

concentrations and corresponding DO saturation values 

than samples collected during the summer. The low 

DO concentrations and saturations values correspond 

to periods of low streamflow and high water 

temperatures, as well as increased biological 

consumption of DO during the summer. 

Dissolved Ions

The term “dissolved ions” represents a group of 

naturally occurring solutes in water; observed 

concentrations can be caused by a combination of 

natural and anthropogenic sources in a drainage basin. 

Selected dissolved ions for the fixed sites are discussed 

in the following sections. All dissolved ions analyzed 

in samples from the nine fixed sites are summarized in 

tables 4 and 5.

Calcium is the most abundant of the alkalineearth elements and is a major component of the solutes 

in most natural water (Hem, 1992). Median calcium
Water Quality of Selected New England Coastal Basins Rivers 15

Figure 7. Water temperature, concentration of dissolved oxygen (same scales), and instantaneous streamflow at the Aberjona River, 

Mass., 1998-2000.

concentrations ranged from 5.2 (Stillwater River) to 

29.4 mg/L (Aberjona River) in the indicator basins and 

from about 4.9 (Kennebec River) to 14.2 mg/L 

(Charles River) in the integrator basins (tables 4 and 5, 

fig. 8). Calcium concentrations correlated with the 

percentage of urban land in the drainage basin for both 

indicator and integrator basins (table 6). Calcium 

concentrations were highest at the sites representing 

moderately to intensely urban land use and smallest at 

sites representing minimal urban land use (fig. 8).

Dissolved sulfate occurs naturally in rivers from 

rock weathering and biological or biochemical 

processes (Hem, 1992). Atmospheric deposition of 

sulfate from the combustion of fuels and the smelting 

of ores is another major source to rivers (Hem, 1992). 

Median sulfate concentrations ranged from 6.9 

(Stillwater River) to 25.8 mg/L (Aberjona River) in the 

indicator basins and from 7.1 (Kennebec River) to 

12.25 mg/L (Charles River) in the integrator basins 

(tables 4 and 5, fig. 8). Like calcium, the percentage of 

urban land use in the drainage basin affects sulfate 

concentrations among the indicator and integrator 

basins (table 6). Among the indicator sites, sulfate 

concentrations were generally highest in the intensely 

urbanized Aberjona River and lowest in the minimally 

urbanized Stillwater River. Sulfate concentrations 

were statistically similar in the Saugus and Ipswich 

Rivers (56 and 38 percent urban land use, respectively); 

and in the Neponset and Wading Rivers (30 and

18 percent urban land use, respectively) (fig. 8). 

Chloride in pristine, natural freshwater is at 

generally low concentrations (less than 4 mg/L). High 

chloride concentrations occur in streams experiencing 

inflows of high-chloride ground water, anthropogenic 

inputs such as stormwater runoff carrying road deicing 

salt, or marine tidal effects (Hem, 1992). Median 

chloride concentrations ranged from 18.3 (Stillwater 

River) to 108 mg/L (Aberjona River) in the indicator 

drainage basins and from 5.4 (Kennebec River) to

68.2 mg/L (Charles River) in the integrator drainage 

basins (tables 4 and 5, fig. 8). Chloride concentrations 

were correlated with urbanization for both indicator 

and integrator basins (table 6). The Saugus River 

sampling site is near a tidal estuary, and some high 

chloride concentrations may be attributed to marine 

effects. For both the indicator and integrator drainage 

basins, chloride concentrations were lowest in the 

drainage basins containing the smallest percentage of 

urban land use. 

Concentrations of many of the dissolved ions 

show the same relations to seasons and streamflow as 

specific conductance. For example, concentrations of 

calcium are highest in the summer during low 

streamflows. Chloride concentrations are highest in 

the summer, but similarly high concentrations also are

Water temperature

 Dissolved oxygen

 Instantaneous 

 streamflow

OND

1999

J F MA MJ J A S OND

2000

J F MA MJ J A S

STUDY PERIOD, IN MONTHS

0

5

10

15

20

25

30

0

50

100

150

200

250

300

350

400

Aberjona River

WATER TEMPERATURE, IN DEGREES CELSIUS

DISSOLVED OXYGEN CONCENTRATION,

IN MILLIGRAMS PER LITER

INSTANTANEOUS STREAMFLOW AT SAMPLE TIME,

IN CUBIC FEET PER SECOND

1998
16 Water Quality of Selected Rivers in the New England Coastal Basins, 1998-2000

EXPLANATION

 Data for sites that have the same letter designation 

 do not differ significantly at the alpha=0.05 level

 Number of samples

 Highest value

 75th percentile

 50th percentile (median)

 25th percentile

 Lowest value

 Percent urban land use upstream of the sampling site

CHLORIDE CONCENTRATION, 

IN MILLIGRAMS PER LITER

A. Indicator sites B. Integrator sites

Stillwater Wading Neponset Ipswich Saugus Aberjona

(27)

Kennebec Merrimack Charles

A

[4] [18] [30] [38] [56] [68] [1] [9] [30]

[4]

SULFATE CONCENTRATION,

IN MILLIGRAMS PER 

CALCIUM CONCENTRATION,

IN MILLIGRAMS PER LITER

RIVER

(51)

A

50.3

(24) (26)

B C

0

10

20

30

40

(75)

A

0

10

20

30

40

(27) (29)

(27) (29)

(27)

B

C D

F E

0

10

20

30

40

(29) (27)

(29)

(27)

A

B

C BC

(75)

A

259

(27)

B (29)

B

(27)

C

(29)

C

(26)

D

(75)

A

63.1

0

50

100

150

(24)

(24)

B

C

(26)

(26)

B

B

(51)

(51)

A

A

0

10

20

30

40

0

50

100

150

(26)

D

Figure 8. Distribution of calcium, sulfate, and chloride concentrations at the (A) six indicator and (B) three integrator sites in the New England 

Coastal Basins study area. (Location of sites shown in fig. 1.)
Water Quality of Selected New England Coastal Basins Rivers 17

observed during winter months in the Aberjona and 

Ipswich Rivers and are likely attributed to road deicing applications.

Nutrients

The occurrence and distribution of nitrogen and 

phosphorus in rivers are from rocks, soils, vegetation, 

treated wastewater effluents, stormwater runoff from 

urban, agricultural and forested lands, poorly 

functioning septic systems, pet waste, and atmospheric 

deposition (primarily for nitrogen). Nitrogen usually is 

a limiting nutrient for plant growth in estuarine and 

coastal waters, and phosphorus generally is the limiting 

nutrient for plant growth in freshwater bodies. In the 

following paragraphs, the occurrence of nitrogen and 

phosphorus in the sampled rivers are discussed. 

Nitrogen

Median total nitrogen concentrations ranged 

from 0.42 (Stillwater River) to 2.74 mg/L (Aberjona 

River) for the indicator basins and from 0.4 (Kennebec 

River) to 1.16 mg/L (Charles River) for the integrator 

basins (tables 4 and 5, fig. 9). Concentrations of total 

nitrogen, as well as the nitrogen species (nitrite plus 

nitrate, ammonia and organic nitrogen), in the indicator 

and integrator drainage basins were correlated with the 

percentage of urban land in the drainage basin

(table 6); the highest concentrations were measured at 

fixed sites draining moderately to intensely urbanized 

land areas (fig. 9). The intensely urbanized Aberjona 

River had a median total nitrogen concentration that 

was more than two to six times higher than the median 

total nitrogen concentration for other indicator sites. 

The total nitrogen concentrations from both the 

indicator and integrator sites consisted of virtually all 

nitrate and organic nitrogen, with the exception of the 

Aberjona River, which had the highest percentage

(30 percent) of dissolved ammonia (fig. 10). Median 

dissolved ammonia concentrations accounted for five 

percent or less of the median total nitrogen for the other 

five indicator sites (fig. 10). The source of the large 

dissolved ammonia concentrations at the Aberjona 

River is unknown, but possible sources may include 

fertilizers or undocumented point sources. 

No water sample collected from any of the nine 

monitoring sites contained dissolved nitrate 

concentrations higher than the USEPA Maximum 

Contaminant Level (MCL) for drinking water of

10 mg/L (U.S. Environmental Protection Agency, 

2000b). However, many of the total nitrogen 

concentrations were higher than the preliminary 

USEPA total nitrogen nutrient criterion of 0.71 mg/L 

for streams in the Eastern Coastal Plain ecoregion

(U.S. Environmental Protection Agency, 2002b). The 

percentage of samples containing total nitrogen 

concentrations higher than 0.71 mg/L ranged from zero 

for the Stillwater and Kennebec Rivers to 100 for the 

Aberjona River. 

Median instantaneous total nitrogen loads for the 

indicator basins ranged from 26 (Stillwater River) to 

142 kg/d (Aberjona River), and median total nitrogen 

yields ranged from 0.8 (Stillwater River) to 5.9 

kg/d/mi2 (Aberjona River) (table 4, fig. 11). For the 

integrator basins, median total nitrogen loads ranged 

from 1,400 (Charles River) to 14,600 kg/d (Merrimack 

River), and median total nitrogen yields ranged from 

1.2 (Kennebec River) to 5.1 kg/d/mi2 (Charles River) 

(table 5). Calculated yields are designed to remove the 

effect of drainage-basin size on the loads; therefore, 

they provide a better comparison between rivers of the 

effect of land use on loads. Total nitrogen yields were 

correlated with the percentage of urban land use in the 

indicator and integrator basins (table 6). 

Phosphorus

Streamwater samples were analyzed for total 

phosphorus, dissolved phosphorus, and dissolved 

orthophosphorus. Median total phosphorus 

concentrations ranged from 0.02 (Stillwater River) to 

0.04 mg/L (Aberjona River) in the indicator basins and 

from 0.04 (Kennebec River) to 0.07 mg/L (Merrimack 

River) in the integrator basins (tables 4 and 5; fig. 12). 

Total phosphorus concentrations were correlated with 

the percentage of urban land use in the drainage basin 

for the indicator basins, but were not correlated for the 

integrator basins (table 6). Among integrator sites, the 

Merrimack River had the highest median total 

phosphorus concentration (0.07 mg/L) even though the 

Merrimack River drainage basin is not as intensively 

urbanized as the Charles River drainage basin. The 

high median total phosphorus concentration in the 

Merrimack River likely is the result of the presence of 

more than 48 municipal wastewater-treatment facilities 

upstream from the sampling site. The U.S. 

Environmental Protection Agency (2002a) has 

recommended a preliminary total phosphorus criterion
18 Water Quality of Selected Rivers in the New England Coastal Basins, 1998-2000

EXPLANATION

 Data for sites that have the same letter designation 

 do not differ significantly at the alpha=0.05 level

 Number of samples

 Highest value

 75th percentile

 50th percentile (median)

 25th percentile

 Lowest value

 Percent urban land use upstream of the sampling site

TOTAL AMMONIA PLUS 

ORGANIC NITROGEN 

CONCENTRATION,

IN MILLIGRAMS PER LITER

A. Indicator sites B. Integrator sites

Stillwater Wading Neponset Ipswich Saugus Aberjona

(27)

Kennebec Merrimack Charles

A

[4] [18] [30] [38] [56] [68] [1] [9] [30]

[4]

NITRITE PLUS NITRATE 

CONCENTRATION,

IN MILLIGRAMS PER 

TOTAL NITROGEN 

CONCENTRATION,

IN MILLIGRAMS PER LITER

RIVER

0

1

2

3

4

0

1

2

(74)

A

(75)

A

2.82

0

6.85

(74)

(27)

(27) (25)

(26)

E (27)

D

C

C

B

A

0

1

2

3

4

(50)

A

(26)

B

(23)

C

0

1

2

(29)

CE

(27)

E (29)

C

(26)

B

(50)

3.34

A

1

2

(27)

D

(24)

(26)

C

B

(27)

D

(27)

C

(29)

C (29)

B

(27)

BC

5.4

(50)

(24)

(26)

C

B

A

0

1

2

Figure 9. Distribution of total nitrogen, dissolved nitrate plus nitrite, and total ammonia plus organic nitrogen concentrations at the (A) six 

indicator and (B) three integrator sites in the New England Coastal Basins study area.
Water Quality of Selected New England Coastal Basins Rivers 19

Stillwater Wading Neponset Ipswich Saugus Aberjona

100

0

20

40

60

80

TOTAL NITROGEN

CONCENTRATION, IN PERCENT

EXPLANATION

 Total nitrite, nitrate, plus organic nitrogen concentration

 Dissolved ammonia concentration, as nitrogen

Kennebec Merrimack Charles

100

0

20

40

60

80

A. Indicator sites B. Integrator sites

RIVER

120 120

Figure 10. Composition of total nitrogen concentrations in the (A) six indicator and (B) three integrator basins in the New England 

Coastal Basins study area.

EXPLANATION

 Data for sites that have the same letter designation 

 do not differ significantly at the alpha=0.05 level

 Number of samples

 Highest value

 75th percentile

 50th percentile (median)

 25th percentile

 Lowest value

 Percent urban land use upstream of the sampling site

Stillwater Wading Neponset Ipswich Saugus Aberjona

(27)

A

[4] [18] [30] [38] [56] [68]

[4]

RIVER

(75)

A

TOTAL NITROGEN YIELDS,

IN KILOGRAMS PER DAY 

PER SQUARE MILE

A. Indicator sites B. Integrator sites

0

10

20

30

(27)

B

(29)

B (27)

B

(29)

B

B

(27)

94

Kennebec Merrimack Charles

[1] [9] [30]

(50)

A

(24) (26) B A

0

10

20

30

Figure 11. Distribution of instantaneous total nitrogen yields in the (A) six indicator and (B) three integrator sites in the New England Coastal 

Basins study area.
20 Water Quality of Selected Rivers in the New England Coastal Basins, 1998-2000

of 0.031 mg/L for streams in the Eastern Coastal Plain 

ecoregion. This criterion was exceeded in samples 

from all nine sites. The percentage of samples that 

exceeded the recommended total phosphorus criterion 

by site ranged from 15 (Stillwater River) to 100 percent 

(Merrimack River).

Median dissolved orthophosphorus 

concentrations were at or less than the laboratory 

reporting level (LRL) of 0.01 mg/L for the six indicator 

basins, indicating that inorganic suspended phosphorus 

is the primary form of total phosphorus in the water at 

these sites. The composition of total phosphorus at the 

three integrator sites varied; total phosphorus

concentrations from the Charles and Merrimack Rivers 

primarily were composed of suspended phosphorus, 

whereas total phosphorus concentrations at the 

Kennebec River were mostly from dissolved 

phosphorus.

Phosphorus normally is strongly sorbed to 

sediment (Hem, 1992). The relation of total 

phosphorus concentrations to suspended sediment 

concentrations for the indicator and integrator sites is 

shown in figure 13. A LOWESS smoothing line was 

applied to provide a picture of the relation between the 

two variables in the scatter plot. Total phosphorus 

concentrations at the indicator and integrator sites often 

increased when suspended-sediment concentrations 

increased during high streamflows. 

Instantaneous total phosphorus yields were not 

correlated to the percentage of urban land use in the 

drainage basin among either the indicator or integrator 

sites (table 6). The Merrimack River had the highest 

median total phosphorus yield (0.3 kg/d/mi2) among all 

nine sampling sites (tables 4 and 5), likely because of 

the upstream discharge of municipal-wastewater 

effluent.

EXPLANATION

 Number of samples

 Highest value

 75th percentile

 50th percentile (median)

 25th percentile

 Lowest value

 Percent urban land use upstream of the sampling site

Stillwater Wading Neponset Ipswich Saugus Aberjona

(27)

[4] [18] [30] [38] [56] [68]

[4]

RIVER

A. Indicator sites B. Integrator sites

0

Kennebec Merrimack Charles

[1] [9] [30]

TOTAL PHOSPHORUS

CONCENTRATION, 

IN MILLIGRAMS PER LITER

0.1

0.2

(75)

(29)

(27)

(27)

(27)

(29)

0

0.1

0.2

(50)

(24)

(26)

0.22

Figure 12. Distribution of total phosphorus concentrations at the (A) six indicator and (B) three integrator sites in the New England Coastal 

Basins study area.
Water Quality of Selected New England Coastal Basins Rivers 21

Pesticides

Pesticides were analyzed in 50 and 20 water 

samples collected from the Aberjona and Charles 

Rivers, respectively, during 1999 and 2000. Samples 

were analyzed for 44 pesticides and 4 degradation 

products (degradates) that include herbicides, 

insecticides, and fungicides (the compounds analyzed 

are listed in appendix 2). Pesticides were detected at 

both the Aberjona and Charles River sites, but with 

higher detection frequencies from samples collected 

during the spring and summer than during the winter. 

At both sites, herbicides were detected more frequently 

than insecticides, but the concentrations of insecticides 

were higher than the herbicide concentrations.

Sixteen pesticides (11 herbicides, 3 insecticides, 

and 2 degradates) were detected in one or more 

samples in the Aberjona River from April 1999 

through September 2000 at concentrations less than

0.5 μg/L (table 7). Four pesticides were detected in 

more than 50 percent of the samples; these pesticides 

included the herbicides prometon (78 percent) and 

atrazine (58 percent), and the insecticides diazinon

(84 percent) and carbaryl (72 percent). Because the 

Aberjona River Basin is intensely urbanized

(68 percent), with little agriculture (2 percent), the 

pesticides detected likely are from applications to 

homes, businesses, utility right-of-ways, and highways. 

No water samples from the Aberjona River contained a 

pesticide concentration exceeding present USEPA 

drinking-water standards or USEPA criteria for 

protection of freshwater aquatic life (table 7). In three 

water samples from the Aberjona River, however, two 

pesticides were observed at concentrations exceeding 

the Canadian criteria for the protection of freshwater 

aquatic life (Canadian Council of Resources and 

Environmental Ministers, 2001) (table 7). The 

Canadian criteria of 0.2 μg/L for carbaryl was exceeded 

twice in May 1999, with estimated concentrations of 

0.49 and 0.45 μg/L, and once in March 2000, with an 

estimated concentration of 0.21 μg/L (an estimated 

concentration indicates that the compound was 

detected in the water sample, but not accurately 

quantified). The Canadian criteria for the protection of 

freshwater aquatic life of 0.0035 μg/L for chlorpyrifos 

was exceeded twice in May 1999, with concentrations 

of 0.008 and 0.006 μg/L, and once in September 1999, 

with an estimated concentration of 0.01 μg/L. Carbaryl 

and chlorpyrifos are insecticides commonly used 

outdoors in urban areas of the Nation (Larson and 

others, 1997). 

Fourteen pesticides (11 herbicides, 2 insecticides, and 1 degradate) were detected in one or more 

samples collected in the Charles River from May 1999 

through March 2000 (table 7). Three pesticides were 

detected in more than 50 percent of all the samples—

diazinon (80 percent), prometon (70 percent), and 

atrazine (50 percent). Pesticide concentrations 

generally were lower in the Charles River than 

concentrations in the Aberjona River. None of the 

water samples analyzed for pesticides in the Charles 

River exceeded any USEPA drinking water or United 

States or Canadian criteria for the protection of 

freshwater aquatic life.

Seasonal variations in pesticide concentrations 

and occurrence were observed in samples from the 

Aberjona River. Detection frequencies were greatest in 

spring and summer. The highest concentrations of 

atrazine were detected in samples from the middle and

0.00

0.05

0.10

0.15

0.20

0.25

TOTAL PHOSPHORUS CONCENTRATION, IN MILLIGRAM PER LITER

100

SUSPENDED-SEDIMENT CONCENTRATION, 

IN MILLIGRAMS PER LITER

0.00

0.05

0.10

0.15

0.20

0.25

Indicator sites

Integrator sites

LOWESS curve

0 20 40 60 80

Figure 13. Relation between concentrations of total phosphorus and 

suspended sediment for the six indicator sites and three integrator sites in 

the New England Coastal Basins study area.
22 Water Quality of Selected Rivers in the New England Coastal Basins, 1998-2000 Table 7. Statistical summary of pesticide compounds detected in water samples from the Aberjona and Charles Rivers in the New England Coastal Basins study are

[All concentrations are in micrograms per liter (μg/L); All pesticide water samples filtered through a 0.7 micrometer (μm) size glass fiber filter; Min, minimum; Max, maconcentration; H, Herbicide; I, Insecticide; M, Metabolite or break-down product; DCPA, Dimethyl tetrachloroterephthalate; EPTC, Ethyl dipropylthiocarbamate; DDE, dichloroethylene; <, less than; --, not applicable] Pesticide compound name (type) Laboratory reporting level, in μg/L Aberjona River Charles River USEPA drinking water MCL1

1Maximum Contaminant Level (MCL) established by the U.S. Environmental Protection Agency (2000a,b,c).

USEPA chron

criteria for 

freshwater 

aquatic life

2Chronic criteria recommendations developed by the U.S. Environmental Protection Agency for the protection of freshwater aquatic life. Chronic is defined by the 

Protection Agency as the 4-day average concentration of targeted compound not to exceed criteria more than once every 3 years, on average (accessed on May 30, 2002, http://www.epa.gov/waterscience/criteria/atrazine/atrazinefacts.html).

3Canadian water-quality guidelines for the protection of freshwater aquatic life (Canadian Council of Resources and Environmental Ministers, 2001).

Sample 

size

Percent 

detection

Concentration Sample 

size

Percent 

detection

Concentration

Min Max Min Max

Atrazine (H) 0.001 50 58 <0.001 0.009 20 50 <0.001 0.010 3 12 Benfluralin (H) .002 50 8 e .001 e .003 20 5 <.002 e .002 -- -- Carbaryl (I) .003 50 72 <.003 e .49 20 40 <.003 e .098 -- -- Chlorpyrifos (I) .004 50 6 <.004 e .010 20 0 <.004 <.004 -- -- Cyanazine (H) .004 50 0 <.004 <.007 20 5 <.004 .008 -- -- 

--

DCPA (Dacthal) (H) .002 50 2 <.002 e .001 20 25 e .001 .010 -- -- Deethyl Atrazine (M) .002 50 30 <.002 e .006 20 20 <.002 e .004 -- -- Diazinon (I) .002 50 84 <.002 .27 20 80 <.002 .036 -- -- EPTC (H) .002 50 4 e .001 e .003 20 5 <.002 e .001 -- -- Metolachlor (H) .002 50 46 e .0019 .008 20 10 <.002 .006 -- -- Napropamide (H) .003 50 2 <.003 .029 20 0 <.003 <.003 -- -- p,p’- DDE (M) .006 49 4 <.006 e .002 20 0 <.006 <.006 -- Pendimethalin (H) .004 49 16 <.004 .024 20 5 <.004 .017 -- Prometon (H) .018 50 78 e .004 .021 20 70 <.018 e .010 -- -- Simazine (H) .005 50 40 e .003 .007 20 35 <.005 .008 4 -- Tebuthiuron (H) .010 50 26 e .001 e .010 20 5 <.010 e .002 -- -- Trifluralin (H) .002 50 30 e .0014 .005 20 10 <.002 e .003 -- -- 
Water Quality of Selected New England Coastal Basins Rivers 23

late summer in 1999 and 2000. The two highest 

concentrations of prometon, a herbicide typically 

applied to control vegetation in utility right-of-ways, 

were in samples from October and November 1999. 

Metolachlor, an herbicide used primarily to control 

vegetation on agricultural lands, was detected in

46 percent of the samples from the Aberjona River and 

had the greatest number of detections in samples from 

late winter through mid summer. Few detectable 

concentrations of metolachlor were from samples 

collected in the fall and early winter. Higher 

concentrations of carbaryl and diazinon were observed 

in samples from May through October 1999, and from 

June through August 2000, than in other parts of the 

year. The highest insecticide concentrations were 

detected during the spring through fall months because 

these months are times of increased insect activity in 

New England. Seasonal variations in pesticide 

detection frequencies were less apparent in the Charles 

River than in the Aberjona River; although 

concentrations of atrazine and diazinon generally were 

higher in the summer than in other times of the year. 

Volatile Organic Compounds

A variety of fuel, solvent, fumigants, 

refrigerants, and disinfection by-product compounds 

were found in the Aberjona and Charles Rivers at 

levels that are mostly less than freshwater aquatic life 

protection and drinking-water criteria. Eighty-four 

VOCs were analyzed in 23 and 29 water samples from 

the Aberjona and Charles Rivers, respectively, from 

October 1998 through March 2000 (appendix 3). 

Thirty different VOCs were detected in the Aberjona 

River; but only six of these compounds were detected 

at concentrations higher than the LRL (fig. 14). The 

remaining 24 compounds were at estimated 

concentrations less than the LRL. Water samples from 

the Charles River contained 29 VOCs, 10 of which had 

concentrations greater than the LRL. The solvents 

trichloroethylene (TCE), tetrachloroethylene (PCE), 

and cis-1,2- dichloroethylene (cis-DCE) were detected 

in all water samples from both rivers. The gasoline 

oxygenate methyl-tert-butyl ether (MTBE) and 

chloroform, a by-product of water chlorination and a 

widely used solvent, were found in all water samples 

from the Aberjona River and in 96 percent of the 

Charles River samples. 

No VOC concentrations exceeded either USEPA 

freshwater acute and chronic toxicity criteria or 

Canadian water-quality guidelines as defined by Rowe 

and others (1997). One sample from the Charles River 

had a TCE concentration of 17.3 μg/L, which 

approached the Canadian TCE guideline of 21 μg/L, 

and one sample from the Aberjona River had a 

chloroform concentration of 1.87 μg/L, near the 

Canadian guideline of 2.0 μg/L. Two water samples 

from the Charles River had TCE concentrations that 

exceeded the USEPA MCL of 5 μg/L for drinking 

water (U.S. Environmental Protection Agency, 2000b); 

however, the Charles River at Watertown is not used as 

a drinking-water supply. Although concentrations of 

most individual compounds did not exceed current 

(2003) guidelines, the long-term and synergistic effects 

on aquatic life of a large number of VOCs detected at 

low levels in the two rivers is unknown and may be 

cause for concern.

Seasonal occurrence patterns of the commonly 

detected VOCs provide clues to the possible sources of 

these compounds. In both the Aberjona and Charles 

Rivers, chloroform concentrations, a by-product of 

water chlorination, are highest in the summer when 

reduced streamflows lessen the effects of dilution and 

the irrigation of lawns and gardens with chlorinated 

municipal water is common (figs. 15 and 16). This 

seasonal pattern also is evident in the Aberjona River 

for concentrations of bromodichloromethane. 

Bromodichloromethane is another by-product of 

chlorinated municipal drinking water, and was detected 

in 11 of the 23 samples collected at the Aberjona River, 

with the highest concentrations measured from June 

through September 1999. 

Concentrations of MTBE show different 

seasonal patterns in the Charles and Aberjona Rivers. 

In the Aberjona River, concentrations were highest in 

the cool months; this seasonal pattern may be attributed 

to low volatilization of these compounds at 

comparatively low temperatures (Lopes and Price, 

1997; and National Science and Technology Council, 

1997) (fig. 15). Conversely, the Charles River had the 

highest MTBE concentrations in the summer when 

volatilization is expected to be highest (fig. 16). This 

occurrence pattern suggests a potential ground-water 

source of MTBE in the Charles River. In addition, the 

use of recreational motorized boats is extensive 

upstream of the monitoring site during the summer and 

the use of reformulated gasoline and oils by these boats 

also may be a source of MTBE.
24 Water Quality of Selected Rivers in the New England Coastal Basins, 1998-2000

0.001 0.01 10 100 1,000

Vinyl chloride

Trichlorofluoromethane Styrene o-Ethyl toluene

Diisopropyl ether

Chloromethane

2-Butanone

1,4-Dichlorobenzene

trans-1,2-Dichloroethylene Ethylbenzene Methylene chloride 1,2,4-Trimethylbenzene

Dibromochloromethane

Acetone

o-Xylene 4-Methyl-2-pentanone 4-Isopropyl-1-methylbenzene

Bromodichloromethane

1,1,2-Trichlorotrifluoroethane m- and p-Xylene 1,1-Dichloroethylene

tert-Pentyl methyl ether

1,1-Dichloroethane

Benzene

1,1,1-Trichloroethane Trichloroethylene Tetrachloroethylene

Methyl tert-butyl ether

cis-1,2-Dichloroethylene

Chloroform 100

100

100

100

100

86

73

65

60

52

52

47

47

30

26

26

21

21

17

17

13

13

4

4

4

4

4

4

4

4

1,1,2-Trichlorotrifluoroethane

4-Isopropyl-1-methylbenzene

n-Propylbenzene

Chloromethane 4-Methyl-2-pentanone

Chlorobenzene 1,3,5-Trimethylbenzene

o-Ethyl toluene

Styrene

1,4-Dichlorobenzene

Bromodichloromethane

trans-1,2-Dichloroethylene

Methylene chloride

Acetone

1,1-Dichloroethane

Ethylbenzene

o-Xylene

1,1-Dichloroethylene

1,2,4-Trimethylbenzene

m- and p-Xylene

Vinyl chloride

tert-Pentyl methyl ether

Benzene

1,1,1-Trichloroethane

Methyl tert-butyl ether

Chloroform

cis-1,2-Dichloroethylene

Trichloroethylene

Tetrachloroethylene

96

96

93

72

72

58

51

44

41

37

34

34

20

17

17

13

13

13

13

13

10

6

3

3

3

3

EXPLANATION

 Laboratory reporting level

 Estimated concentration

 Measured concentration

CONCENTRATION, IN MICROGRAMS PER LITER

B. Charles River

A. Aberjona River

CONCENTRATION, IN MICROGRAMS PER LITER

VOLATILE ORGANIC COMPOUND VOLATILE ORGANIC COMPOUND

PERCENTAGE OF SAMPLES WITH DETECTIONS 

OF VOLATILE ORGANIC COMPOUNDS

PERCENTAGE OF SAMPLES WITH DETECTIONS 

OF VOLATILE ORGANIC COMPOUNDS

0.1 1

0.001 0.01 10 100 1,000

100

100

100

0.1 1

Figure 14. Concentrations of volatile organic compounds detected in water samples in the (A) Aberjona and (B) Charles Rivers, Mass.
Water Quality of Selected New England Coastal Basins Rivers 25

Concentrations of the solvents cis-DCE, PCE 

and TCE in both rivers also were highest in the 

summer, when streamflows were lowest. 

Concentrations of cis-DCE, PCE and TCE in the 

Aberjona River also were high in the winter when 

streamflow was less than 20 ft3/s, but may be attributed 

to low volatilization of these compounds at cool 

temperatures. This year-round inverse relation to 

streamflow indicates that cis-DCE, PCE and TCE 

concentrations may be from a continuous source(s), 

such as a point source or ground-water discharge.

A M J J A S O N D J F M A

1999 2000

5

0

1

2

3

4

400

0

100

200

300

STREAMFLOW, 

IN CUBIC FEET PER SECOND

STUDY PERIOD, IN MONTHS

Aberjona River

CHLOROFORM AND METHYL TERT-BUTYL

ETHER CONCENTRATIONS,

IN MICROGRAMS PER LITER

 Chloroform

 Methyl tert-butyl ether

 Daily mean streamflow

O N D J F M A M J J A S O N D J F M

1998 1999 2000

0 0

1,200

200

400

600

800

1,000

STREAMFLOW, IN CUBIC FEET PER SECOND

STUDY PERIOD, IN MONTHS

Charles River

CHLOROFORM AND METHYL TERT-BUTYL

ETHER CONCENTRATIONS,

IN MICROGRAMS PER LITER

 Chloroform

 Methyl tert-butyl ether

 Daily mean streamflow

0.5

1.0

1.5

2.0

Figure 15. Chloroform and methyl tert-butyl ether concentrations, and daily mean streamflow in the Aberjona River, Mass., from April 1999 to 

April 2000.

Figure 16. Chloroform and methyl tert-butyl ether concentrations in the Charles River at Watertown, Mass., and daily mean streamflow at the 

Charles River at Waltham, Mass., from October 1998 to April 2000.
26 Water Quality of Selected Rivers in the New England Coastal Basins, 1998-2000

WATER-QUALITY CONDITIONS OF 

MONITORING SITES IN THE NEW 

ENGLAND COASTAL BASINS, LONG 

ISLAND-NEW JERSEY COASTAL 

DRAINAGES, AND OTHER NATIONAL 

WATER-QUALITY ASSESSMENT 

PROGRAM URBAN SITES

The presence and concentrations of selective 

nutrients, pesticides, and VOCs in the Aberjona and 

Charles River monitoring sites were similar and 

different to what was found as part of NAWQA studies 

in the LINJ study unit in the New York City 

metropolitan region and across the Nation. Ayers and 

others (2000) presents a summary of findings from the 

LINJ study, and a summary of NAWQA Program 

findings nationally for nutrients and pesticides are 

reported in U.S. Geological Survey (1999). 

Nutrients

The median total nitrogen concentration in the 

Aberjona River (2.7 mg/L) was more than twice the 

median total nitrogen concentration found in Bound 

Brook, New Jersey (1.27 mg/L), and the median 

concentration of 48 urbanized NAWQA indicator sites 

(1.27 mg/L) across the Nation (fig. 17a). The median 

total nitrogen concentration in the other five NECB 

indicator sites all were less than the national NAWQA 

median concentration. In a comparison of median total 

nitrogen concentrations for integrator sites, all three of 

the NECB integrator sites had lower median total 

nitrogen concentrations than was found in the Passaic 

River in New Jersey and in 28 other NAWQA 

integrator sites throughout the Nation (fig. 17a). 

Median total phosphorus concentrations for all 

NECB indicator and integrator sites were lower than 

what was found at the two LINJ and 76 NAWQAsampled sites (fig. 17b). Median total phosphorus 

concentrations were nearly six times higher in the 

Passaic River than in the similar-sized and urbanized 

Charles River, more than four times higher than the 

Merrimack River, and nearly two times higher than the 

national median concentration for 28 integrator sites. 

The high concentrations of total nitrogen and total 

phosphorus in the Passaic River are likely from the 

presence of 22 municipal wastewater-treatment facility 

discharges in the drainage basin upstream of the 

sampling site (Reiser and O’Brien, 1998). The Charles 

River has five municipal wastewater-treatment facility 

discharges upstream of the sampling site

(Laura Hayes, U.S. Geological Survey, written 

commun., 2002). As previously noted, the Merrimack 

River also has numerous municipal wastewatertreatment facility discharges upstream from the 

sampling site. 

The generally lower concentrations of median 

total nitrogen and median total phosphorus in NECB 

rivers than what were found in the LINJ rivers and 

other NAWQA-sampled rivers nationally may be due 

to a variety of factors. These factors include nutrientpoor glacial sediments and soils in comparison to soils 

in other areas of the Nation, riparian stream banks that 

are more vegetated and less developed than found 

elsewhere in other urban areas of the Nation, and an 

appreciable percentage of treated, municipal 

wastewater being directly discharged to offshore 

coastal waters near Boston (Medalie, 1996).

Pesticides

Median concentrations and detection frequencies 

of the four pesticides atrazine, prometon, carbaryl, and 

diazinon were higher in the two LINJ rivers than in 

either the NECB streams or in 33 other NAWQA urban 

streams sampled throughout the Nation (figs. 18a and 

b). The insecticides carbaryl and diazinon were 

detected more frequently and at higher median 

concentrations in the Aberjona River than the median 

of 33 other urban streams sampled throughout the 

Nation (figs. 18a and b). Overall, pesticide detections 

were more frequent and at higher concentrations in the 

spring and summer growing seasons in both the LINJ 

(Reiser, 1999) and NECB sites than in winter, 

indicating that the pesticides likely are being 

transported to the streams by storm runoff soon after 

applications.

Volatile Organic Compounds

Median VOC concentrations and detection 

frequencies of TCE, PCE, cis-DCE, MTBE, were 

higher in the Aberjona and Charles Rivers than in the 

two LINJ rivers and in 26 other urban rivers monitored 

by the NAWQA Program throughout the Nation
Water-Quality Conditions of Monitoring Sites in the New England Coastal Basins, Long Island-New Jersey Coastal Drainages, and Other Urban Sites 27

0.0

0.5

1.0

1.5

2.0

2.5

3.0

MEDIAN TOTAL NITROGEN CONCENTRATION, 

IN MILLIGRAMS PER LITER

Indicator sites Integrator sites

Stillwater River

Wading River

Neponset River

Ipswich River

Saugus River

Aberjona River

Bound Brook

NAWQA (48 urban sites)

Kennebec River

Merrimack River

Charles River

Passaic River

NAWQA (28 urban sites)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

MEDIAN TOTAL NITROGEN CONCENTRATION, 

IN MILLIGRAMS PER LITER

EXPLANATION

Study area

 New England Coastal Basin

 Long Island-New Jersey

 76 NAWQA urban sites throughout the Nation

Integrator sites

0.00

0.08

MEDIAN TOTAL PHOSPHORUS CONCENTRATION, 

IN MILLIGRAMS PER LITER

Indicator sites

Stillwater River

Wading River

Neponset River

Ipswich River

Saugus River

Aberjona River

Bound Brook

NAWQA (48 urban sites)

0.07

0.06

0.05

0.04

0.03

0.02

0.01

Kennebec River

Merrimack River

Charles River

Passaic River

NAWQA (28 urban sites)

0.00

MEDIAN TOTAL PHOSPHORUS CONCENTRATION, 

IN MILLIGRAMS PER LITER

0.35

0.30

0.25

0.20

0.15

0.10

0.05

A. Nitrogen

B. Phosphorus

Figure 17. Median total nitrogen (A) and median total phosphorus concentrations (B) of the New England Coastal Basins (NECB) fixedsite network in relation to the Long Island-New Jersey (LINJ) study area basins at Bound Brook at Middlesex and Passaic River at Two 

Bridges, N.J., and 76 urban rivers monitored by the National Water-Quality Assessment (NAWQA) Program throughout the Nation by 

indicator and integrator sites.
28 Water Quality of Selected Rivers in the New England Coastal Basins, 1998-2000

0

20

40

60

80

100

ATRAZINE PROMETON CARBARYL DIAZINON

FREQUENCY OF DETECTION, IN PERCENT, 

INCLUDING ESTIMATED VALUES

PESTICIDE COMPOUND

A. Pesticide concentration

B. Pesticide detection*

0.00

0.01

0.02

0.03

0.04

0.05

0.06

ATRAZINE PROMETON CARBARYL DIAZINON

 (50)

(44)

(887)

(44)

(50)

(44)

(44)

(50) (50)

(897)

(870)

MEDIAN PESTICIDE CONCENTRATION, 

IN MICROGRAM PER LITER

(877)

(20)

(7)

(7)

(20)

(7)

(20)

(20)

(7)

PESTICIDE COMPOUND

EXPLANATION

 Aberjona River, indicator site

 Charles River, integrator site

 Bound Brook, indicator site

 Passiac River, integrator site

 Median of 26 urban rivers throughout the Nation

(50) Number of samples

* Number of samples are the same for graphs A and B

Figure 18. Median concentrations (A) and frequency of detection (B) of the pesticide compounds atrazine, prometon, 

carbaryl, and diazinon in the Aberjona River at Winchester, Mass., Bound Brook at Middlesex, N.J., Charles River at 

Watertown, Mass., and Passaic River at Two Bridges, N.J., in relation to 33 urban rivers monitored by the National Water 

Quality Assessment Program (NAWQA) throughout the Nation. A median of 0.0 indicates that the median concentration 

was less than the NAWQA long-term method detection level for that compound.
Water-Quality Conditions of Monitoring Sites in the New England Coastal Basins, Long Island-New Jersey Coastal Drainages, and Other Urban Sites 29

0.0

0.5

1.0

1.5

2.0

CHLOROFORM cis-DCE PCE TCE

 (50) (49) (711) (49) (49) (49) (711) (711)

MEDIAN VOLATILE ORGANIC COMPOUND CONCENTRATION, 

IN MICROGRAMS PER LITER

(711) (20)

(10)

(10) (10)

(20)

(10)

VOLATILE ORGANIC COMPOUND

 (50)

(50)

MTBE

(711)

(49)

(50)

(50) (20)

(20)

(20)

(10)

0

20

40

60

80

100

CHLOROFORM cis-DCE PCE TCE

FREQUENCY OF DETECTION, IN PERCENT, 

INCLUDING ESTIMATED VALUES

VOLATILE ORGANIC COMPOUND

MTBE

EXPLANATION

 Aberjona River, indicator site

 Charles River, integrator site

 Bound Brook, indicator site

 Passiac River, integrator site

 Median of 26 urban rivers throughout the Nation

(50) Number of samples

* Number of samples are the same for graphs A and B

A. Volatile organic compound concentration

B. Volatile organic compound detection*

Figure 19. Median concentrations (A) and frequency of detection (B) of the volatile organic compounds chloroform, cis-1,2, dichloroethene (cisDCE), tetrachloroethylene (PCE), trichloroethylene (TCE), and methyl tert-butyl ether (MTBE) in the Aberjona River at Winchester, Mass., Bound Brook 

at Middlesex, N.J., Charles River at Watertown, Mass., and Passaic River at Two Bridges, N.J., in relation to 26 urban rivers monitored by the 

National Water Quality Assessment Program (NAWQA) throughout the Nation. A median concentration of 0.0 indicates that the median 

concentration was less than the NAWQA long-term method-detection level for that compound.
30 Water Quality of Selected Rivers in the New England Coastal Basins, 1998-2000

(figs. 19a and b). Regionally, median concentrations of 

the gasoline additive MTBE were higher in the NECB 

and LINJ rivers, especially in the Aberjona River and 

Bound Brook indicator sites, than the median 

concentration of 26 other urbanized rivers throughout 

the Nation. MTBE was detected in nearly all of the 

water samples in the NECB and LINJ streams 

compared to 44 percent nationally. The median TCE 

concentration (1.17 μg/L) and detection frequency

(100 percent) in the Charles River integrator drainage 

basin was higher than in either the Passaic River (less 

than 0.1 μg/L and 40 percent) or the national NAWQA 

median (0.09 μg/L and 41 percent). 

Chloroform was the only VOC compound 

detected more frequently and at a higher median 

concentration in a LINJ sampling stream (the Passaic 

River) than in either of the NECB sampling streams. 

Chloroform concentrations were highest in both the 

NECB and LINJ streams in summer and during low 

flows. In the Passaic River, the chloroform 

concentrations may be related to the presence of 

numerous chlorinated wastewater discharges (Reiser 

and O’Brien, 1998, table 9, p. 6). In contrast, 

chlorinated wastewater discharges in the Aberjona and 

Charles Rivers are minimal, indicating that chloroform 

in the NECB sites may be derived from nonpoint 

sources, especially runoff from the irrigation of lawns 

and gardens. 

The two LINJ rivers had higher concentrations 

of MTBE, TCE, and PCE in water samples collected 

during the winter than in water samples collected in the 

summer (Reiser and O’Brien, 1998, table 9, p. 6). In 

contrast, the two NECB rivers had higher 

concentrations of TCE and PCE in water samples 

collected during the summer than in samples collected 

in the winter. The Charles River also had the highest 

MTBE concentrations during the summer (fig. 16). 

These differences in seasonal patterns of VOC 

concentrations between the LINJ and NECB rivers 

indicate that sources and movement of VOCs differ 

between these rivers.

SUMMARY AND CONCLUSIONS

Concentrations of selected major ions and 

nutrients, and values of field parameters in streams of 

the New England Coastal Basins (NECB) study area 

are affected by the amount of urbanization in the 

watershed. This conclusion is based on 2 years of 

routine monitoring, from October 1998 to September 

2000, of nine rivers in the study area by the U.S. 

Geological Survey National Water-Quality Assessment 

(NAWQA) Program. Eight of these nine rivers 

(Aberjona, Saugus, Ipswich, Stillwater, Neponset, 

Wading, Charles, and Merrimack Rivers) are in the 

Boston metropolitan area of Massachusetts; the ninth 

river (Kennebec River) is in central Maine. The nine 

rivers represent a range of urbanization from 1 percent 

(Kennebec River) to 68 percent (Aberjona River). Six 

of the sites represent small drainage basins (less than 

50 mi2) called indicator sites, and three (Kennebec, 

Merrimack, and Charles Rivers) of the sites are called 

integrator sites that drain large (greater than 250 mi2) 

basins.

Specific-conductance data from all rivers were 

correlated with the percentage of urban land use in the 

drainage basin; specific-conductance values increased 

during periods of reduced streamflows and during 

winter months possibly because of road de-icing 

applications. Median pH values in all nine sampling 

sites were around the neutral value of 7; although pH 

values increased as the percentage of urban land use 

increased. Concentrations of dissolved oxygen (DO) in 

water samples from the Aberjona, Charles, and 

Merrimack Rivers were below the Massachusetts 

minimum criteria of 5 mg/L during periods of low 

streamflows and high water temperatures. 

Concentrations of the major ions calcium, sodium, 

sulfate, and chloride were correlated with the 

percentage of urban land use in a drainage basin. In the 

intensely urbanized drainage basins, concentrations of 

sodium and chloride increase in the summer and winter 

indicating that low flows and road de-icing applications 

affect concentrations of these ions. 

Concentrations of total nitrogen, as well as the 

various organic and inorganic species of nitrogen, were 

correlated with the percentage of urban land use in a 

drainage basin. Median concentrations for total 

nitrogen and all nitrogen species were highest at the 

sites with the highest percentage of urban land use, 

indicating that the amount of urbanization in a drainage 

basin affects total nitrogen concentrations in the NECB 

study area. Specific sources of the total nitrogen are 

not known, but likely include nonpoint sources such as 

fertilizer application, atmospheric deposition, unknown 

point sources, leaking sewer lines, and contaminated 

ground water. Total nitrogen concentrations from eight 

of the nine sites were composed of primarily nitrate 
Summary and Conclusions 31

and organic nitrogen; the exception is the Aberjona 

River, which had a high percentage of ammonia. The 

USEPA preliminary total nitrogen criterion of 0.71 

mg/L for the region frequently was exceeded at many 

of the rivers. Similar to nitrogen concentrations, total 

nitrogen yields were correlated with the percentage of 

urban land use, and the highly urbanized Aberjona and 

Charles Rivers had the highest median total nitrogen 

yields.

Total phosphorus concentrations also were 

correlated with the percentage of urban land use in a 

drainage basin for the indicator basins, but were not for 

the integrator basins. Total phosphorus concentrations 

in the study area typically are composed of inorganic 

suspended phosphorus. Total phosphorus 

concentrations increased with increasing suspendedsediment concentrations at many of the sites. The 

USEPA-recommended total phosphorus criterion of 

0.031 mg/L was exceeded in various samples collected 

from all sites. Instantaneous total phosphorus yields 

were not correlated to the percentage of urban land use 

in a drainage basin among either the indicator or 

integrator sites. Samples from the Merrimack River 

had the highest median total phosphorus yield, likely a 

result of numerous municipal wastewater-effluent 

discharges upstream of the monitoring site. 

Pesticides and volatile organic compounds 

(VOCs) were analyzed in 70 samples from the highly 

urbanized Aberjona and Charles Rivers in the Boston 

metropolitan area. Pesticides frequently were detected 

in samples collected during the spring and summer 

months when pesticide usage is greatest. A total of 16 

different pesticide compounds were detected in the two 

rivers, but at concentrations less than 0.5 μg/L. At both 

sites, herbicides were more commonly detected than 

insecticides. The herbicides prometon and atrazine and 

the insecticide diazinon were detected in more than

50 percent of all samples collected from both rivers. 

No water sample contained pesticide concentrations 

exceeding any USEPA drinking-water standard or 

criteria for protecting freshwater aquatic life. 

However, three water samples from the Aberjona River 

contained two pesticides (carbaryl and chlorpyrifos) at 

concentrations exceeding the Canadian criteria for the 

protection of freshwater aquatic life. 

Volatile organic compounds were frequently 

detected in the Aberjona and Charles Rivers, but at 

concentrations that were generally below USEPA 

drinking-water and freshwater aquatic-life protection 

criteria. The solvents TCE, PCE, and cis-DCE were 

detected in all water samples from both rivers. The 

gasoline oxygenate MTBE and chloroform were 

detected in all 23 water samples from the Aberjona 

River, and in all but 1 of 29 water samples (97 percent) 

from the Charles River. Two water samples from the 

Charles River had TCE concentrations that exceeded 

the USEPA Maximum Contaminant Level (MCL) of

5 μg/L for drinking water (although the Charles River 

is not used as a drinking-water supply at the sampling 

site). 

The VOCs chloroform, cis-DCE, PCE, and TCE 

had high concentrations in the summer when 

streamflows are lowest indicating that these 

compounds may be originating from a continuous 

source such as an unknown point source or groundwater recharge. MTBE concentrations in the Aberjona 

River were highest in the winter. Conversely, the 

Charles River had high concentrations of MTBE in 

samples from the summer when volatilization is 

expected to be greatest; recharge from gasolinecontaminated discharge from ground water and(or) 

recreational motorized boats upstream (that use 

reformulated gasoline and oils) of the monitoring site 

may be sources of MTBE to the river.

Water-quality conditions were compared to 

conditions in two NAWQA-sampled rivers in the New 

York City metropolitan area, and to NAWQA-sampled 

rivers in other urban areas across the Nation. Median 

total nitrogen and total phosphorus concentrations in 

the NECB rivers sampled generally were lower than 

median concentrations found in other NAWQA urban 

rivers sampled in the Long Island-New Jersey (LINJ) 

area and across the Nation. The one exception was the 

Aberjona River. The median total nitrogen 

concentration in this river was almost twice the median 

concentration found in other NAWQA urban rivers 

nationally. Possible explanation for the low nutrient 

concentrations in the NECB study area include the 

presence of nutrient-poor glaciated sediments and 

soils, riparian stream banks that are more vegetated and 

less developed than elsewhere in other urban areas of 

the Nation, and an appreciable percentage of treated, 

municipal wastewater being directly discharged to 

offshore coastal waters. 

The most frequently detected pesticides in two 

NECB rivers (atrazine, carbaryl, diazinon and 

prometon) generally had median concentrations lower 

than concentrations in urbanized rivers in the LINJ area 

and nationally. Median concentrations of carbaryl and 
32 Water Quality of Selected Rivers in the New England Coastal Basins, 1998-2000

diazinon in the Aberjona River near Boston, however, 

were higher than the median of all other NAWQA 

urban rivers. 

The VOC compound MTBE was detected in 

nearly 100 percent in the NECB and LINJ rivers 

compared to the national median of 44 percent—a 

reflection of the high use of MTBE in gasoline in the 

Boston and New York City metropolitans areas. The 

median PCE concentration in the Charles River was 

more than six times higher than the median 

concentrations in the LINJ rivers or other urbanized 

NAWQA sampling sites. Median concentration and 

detection frequencies of TCE, PCE, and cis-DCE were 

higher in the two NECB rivers than in the two LINJ 

rivers. Chloroform was the only VOC found more 

frequently and at a higher median concentration in a 

LINJ river than in the two NECB rivers. Differences in 

seasonal patterns of VOC concentrations between the 

NECB and LINJ rivers indicate that sources and 

movement of VOCs differ among the four rivers in the 

two study areas.

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1990s National land cover data set for the conterminous 

United States from LANDSAT thematic mapper data 

and ancillary data sources: Photogrammetric 

Engineering and Remote Sensing, v. 67, p. 650-652.

Weinstein, M.J., Kennedy, L.E., and Colonna-Romano, Jane, 

2001, Nashua River Basin 1998 Water Quality 

Assessment Report: Massachusetts Department of 

Environmental Protection, Division of Watershed 

Management, Report No. 81-AC-3, variously paged.

Wilde, F.D., and Radte, D.B., eds., 1998, National field 

manual for the collection of water-quality data: U.S. 

Geological Survey Techniques of Water-Resources 

Investigations, book 9, chap. A6, variously paged.

Zarriello, P.J., 2002, Effects of water-management 

alternatives on streamflow in the Ipswich River Basin, 

Massachusetts: U.S. Geological Survey Open-File 

Report 01-483, 35 p.
34 Water Quality of Selected Rivers in the New England Coastal Basins, 1998-2000 Table 4. Summary statistics for selected water-quality constituents in the six indicator sites in the New England Coastal Basins study area, 1998-2000 [Min, minimum; Med, median; Max, maximum; μs/cm, microsiemens per centimeter at 25oC; oC, degrees Celsius; mg/L, milligrams per liter; <, less than; kg/d, kilogram

day per square mile; μg/L, micrograms per liter] Water-quality constituent Indicator sites Aberjona River Ipswich River 

Sample size Min Med Max Sample size Min Med Max Sample size 

Field measurements Specific conductance, in μs/cm at 25oC 76 150 521 1,010 29 166 265 345 27 1

pH, standard units 41 6.9 7.1 7.5 16 6.4 6.7 7.1 11 Water temperature, in oC 76 0.2 14.9 24.8 29 0.1 8 23.1 27 Dissolved oxygen, in mg/L as O2 76 3.1 8 15 29 6.3 10.2 12.6 27 Dissolved oxygen, percent saturation 75 35 79.5 110 29 73 85 94 27 Alkalinity, dissolved, incremental (mg/L as CaCO3) 70 20 53 75 28 10 21 44 25 

Major ions Calcium, dissolved (mg/L as Ca) 75 8.39 29.4 39.3 29 7.33 12.1 14.9 27 

Magnesium, dissolved (mg/L as Mg) 75 1.38 5.09 6.56 29 1.61 2.77 3.36 27 Sodium, dissolved (mg/L as Na) 75 14.6 58.1 148 29 16.9 31 47.5 27 Potassium, dissolved (mg/L as K) 75 1.82 3.37 4.28 29 1.67 2.34 4.76 27 Sulfate, dissolved (mg/L as SO4) 75 9.9 25.8 63.1 29 4.8 12.5 28.8 27 Chloride, dissolved (mg/L as CL) 75 22.1 108 259 29 26.3 56.1 82.2 27 Fluoride, dissolved (mg/L as F) 75 <0.1 0.1 0.3 29 <0.1 <0.1 0.2 27 Silica, dissolved (mg/L as SiO2) 75 2.7 7.7 10.3 29 1.6 7.6 14.2 27 

Nutrients

Ammonia, dissolved (mg/L as N) 75 0.02 0.82 4.93 29 <0.02 0.03 0.16 27 Ammonia + organic, dissolved

(mg/L as N)

74 .1 1.1 4.5 29 .27 .47 .75 27 

Ammonia + organic, Total (mg/L as N) 74 .39 1.2 5.4 29 .1 .57 .82 27 
Tables 35

Nutrients--Continued

Nitrite + nitrate, dissolved (mg/L as N) 75 0.23 1.42 2.82 29 0.05 0.23 0.55 27 Nitrite, dissolved (mg/L as N) 75 <.01 0.039 0.25 29 <.01 <.01 .014 27 Nitrogen, Total (mg/L as N) 75 .8 2.74 6.85 29 .46 .81 1.04 27 Nitrogen, Total, load (kg/d) 75 5.9 142 2,260 29 .25 115 660 27 Nitrogen, Total, yield (kg/d/mi2) 75 .24 5.9 94 29 .01 2.6 15 27 Phosphorus, dissolved (mg/L as P) 75 <.004 .008 .03 29 <.004 .013 .1 27 Phosphorus, ortho, dissolved

(mg/L as P)

75 <.01 <.01 .02 29 <.01 <.01 .03 27 

Phosphorus, Total (mg/L as P) 75 .012 .039 .2 29 .011 .03 .07 27 Phosphorus, Total, load (kg/d) 72 .14 1.7 67 26 .009 4.2 21 24 Phosphorus, Total, yield (kg/d/mi2) 72 .006 .07 2.8 26 2.1 e-04 .09 .5 24 Iron, dissolved (μg/L as Fe) 75 20 140 520 29 140 320 1,270 27 1Manganese, dissolved (μg/L as Mn) 75 67.3 201 549 29 18.8 114 1,010 27 

Sediment

Suspended sediment, in mg/L 75 2 7 62 29 1 4 32 27 

Table 4. Summary statistics for selected water-quality constituents in the six indicator sites in the New England Coastal Basins study area, 1998-2000--Continued[Min, minimum; Med, median; Max, maximum; μs/cm, microsiemens per centimeter at 25oC; oC, degrees Celsius; mg/L, milligrams per liter; <, less than; kg/d, kilogram

day per square mile; μg/L, micrograms per liter]

Water-quality constituent

Indicator sites

Aberjona River Ipswich River 

Sample 

size Min Med Max Sample size Min Med Max Sample size 
36 Water Quality of Selected Rivers in the New England Coastal Basins, 1998-2000 Table 4. Summary statistics for selected water-quality constituents in the six indicator sites in the New England Coastal Basins study area, 1998-2000--Continued [Min, minimum; Med, median; Max, maximum; μs/cm, microsiemens per centimeter at 25oC; oC, degrees Celsius; mg/L, milligrams per liter; <, less than; kg/d, kilogram

day per square mile; μg/L, micrograms per liter] Water-quality constituent Indicator sites Saugus River Stillwater River 

Sample size Min Med Max Sample size Min Med Max Sample size 

Field measurements Specific conductance, in μs/cm at 25oC 27 160 496 624 27 56 105 153 29 14

pH, standard units 15 6.9 7.2 7.6 13 6 6.5 6.7 13 Water temperature, in oC 27 .1 8.5 21 27 .1 10.3 21.3 29 Dissolved oxygen, in mg/L as O2 27 6.6 10.5 14 26 6.7 9.6 13.3 29 Dissolved oxygen, percent saturation 27 75 89 100 26 69 87 97 29 5Alkalinity, dissolved, incremental (mg/L as CaCO3) 26 18 47.5 76 26 2 8.5 27 27 

Major ions Calcium, dissolved (mg/L as Ca) 27 7.35 19.4 26.7 27 2.26 5.2 10.6 29 

Magnesium, dissolved (mg/L as Mg) 27 2.28 6.61 10.8 27 0.47 1 2.02 29 Sodium, dissolved (mg/L as Na) 27 19.5 54.4 69.7 27 6.2 10.7 32.6 29 1Potassium, dissolved (mg/L as K) 27 1.4 2.57 3.9 27 .7 1.25 2 29 Sulfate, dissolved (mg/L as SO4) 27 6.3 14.8 22.9 27 .1 6.9 10.7 29 Chloride, dissolved (mg/L as CL) 27 32.4 103 137 26 9.7 18.3 53.1 29 2Fluoride, dissolved (mg/L as F) 27 <0.1 <0.1 0.3 26 <.1 <0.1 0.1 29 Silica, dissolved (mg/L as SiO2) 27 3.3 9.1 13.9 27 3.8 6.4 8.5 29 

Nutrients

Ammonia, dissolved (mg/L as N) 27 <0.02 0.04 0.16 27 <0.02 <0.02 0.05 29 <Ammonia + organic, dissolved 

(mg/L as N)

27 .1 .41 .81 27 .06 .21 .38 29 

Ammonia + organic, Total (mg/L as N) 27 .1 .48 .77 27 .06 .29 .53 29 
Tables 37

Nutrients--Continued

Nitrite + nitrate, dissolved (mg/L as N) 26 0.2 0.63 0.88 27 0.06 0.13 0.31 29 <Nitrite, dissolved (mg/L as N) 27 <.01 <.01 .02 27 <.01 <.01 .02 29 Nitrogen, Total (mg/L as N) 27 .7 1.05 1.4 27 .23 .42 .63 29 Nitrogen, Total, load (kg/d) 27 2.3 67 560 27 .54 26 930 29 Nitrogen, Total, yield (kg/d/mi2) 27 .1 2.9 24 27 .02 0.8 29 29 Phosphorus, dissolved (mg/L as P) 27 <.05 .011 .06 27 <.004 .005 .013 29 Phosphorus, ortho, dissolved

(mg/L as P)

27 <.01 .010 .03 27 <.01 <.01 .02 29 

Phosphorus, Total (mg/L as P) 27 <.004 .035 .08 27 <.008 .02 .15 29 Phosphorus, Total, load (kg/d) 24 .1 2.1 34 24 .02 1.1 215 26 Phosphorus, Total, yield (kg/d/mi2) 24 .004 .09 1.5 24 .001 .03 7 26 Iron, dissolved (μg/L as Fe) 27 60 200 530 27 50 140 290 29 9Manganese, dissolved (μg/L as Mn) 27 41.5 97.4 306 27 19.1 43.3 177 29 2

Sediment

Suspended sediment, in mg/L 27 2 4 42 27 2 4 58 29 

Table 4. Summary statistics for selected water-quality constituents in the six indicator sites in the New England Coastal Basins study area, 1998-2000--Continued[Min, minimum; Med, median; Max, maximum; μs/cm, microsiemens per centimeter at 25oC; oC, degrees Celsius; mg/L, milligrams per liter; <, less than; kg/d, kilogram

day per square mile; μg/L, micrograms per liter]

Water-quality constituent

Indicator sites

Saugus River Stillwater River 

Sample 

size Min Med Max Sample size Min Med Max Sample size 
38 Water Quality of Selected Rivers in the New England Coastal Basins, 1998-2000 Table 5. Summary statistics for selected water-quality constituents in the three integrator sites in the New England Coastal Basins study area, 1998-2000 [Min, minimum; Med, median; Max, maximum; μs/cm, microsiemens per centimeter at 25oC; oC, degrees Celsius; mg/L, milligrams per liter; <, less than; kg/d, kilogram

day per square mile; μg/L, micrograms per liter] Water-quality constituent Integrator sites Charles River Kennebec River 

Sample size Min Med Max Sample size Min Med Max Sample size 

Field measurements Specific conductance, in μs/cm at 25oC 52 219 326 450 24 36 67.5 91 27 

pH, standard units 26 6.9 7.2 7.5 12 6.8 7.25 7.5 12 Water temperature, in oC 52 0.1 12 27 24 0.1 7.9 23.5 27 Dissolved oxygen, in mg/L as O2 51 2.2 9.2 14.9 24 7 11.3 14.2 27 Dissolved oxygen, percent saturation 50 26 87 104 23 82 98 110 26 Alkalinity, dissolved, incremental (mg/L as CaCO3) 49 14 27 51 21 8 17 31 23 

Major ions Calcium, dissolved (mg/L as Ca) 51 8.69 14.2 50.3 24 3.14 4.88 6.57 26 

Magnesium, dissolved (mg/L as Mg) 51 2.09 3.18 11.4 24 .69 1.03 1.33 26 Sodium, dissolved (mg/L as Na) 51 25.5 38.4 98.2 24 2 5.85 9.1 26 Potassium, dissolved (mg/L as K) 51 .68 2.62 4.36 24 .53 .74 1.53 26 Sulfate, dissolved (mg/L as SO4) 52 6.4 12.25 24.1 25 3.1 7.1 12.4 27 Chloride, dissolved (mg/L as CL) 51 45.2 68.2 107 24 3.1 5.4 8.4 26 Fluoride, dissolved (mg/L as F) 51 <.1 <0.1 0.2 24 <.1 <.1 <0.1 26 Silica, dissolved (mg/L as SiO2) 51 1.3 5.2 28.1 24 2.5 3.7 5 26 

Nutrients

Ammonia, dissolved (mg/L as N) 50 0.026 0.09 0.57 24 <0.02 <0.02 0.14 26 Ammonia + organic, dissolved

(mg/L as N)

50 .29 .5 .9 23 .1 .24 .34 26 

Ammonia + organic, Total (mg/L as N) 50 .4 .62 1.1 24 .1 .29 .38 26 
Tables 39

Nutrients--Continued

Nitrite + nitrate, dissolved (mg/L as N) 50 0.167 0.53 3.34 24 0.062 0.19 0.16 26 Nitrite, dissolved (mg/L as N) 50 <.01 .012 .06 24 <.01 <.01 .02 26 Nitrogen, Total (mg/L as N) 50 .67 1.16 3.91 24 .19 .4 .53 26 Nitrogen, Total, load (kg/d) 50 56 1,400 5,500 24 1,600 6,560 70,700 26 3Nitrogen, Total, yield (kg/d/mi2) 50 .21 5.1 20 24 .3 1.2 13 26 Phosphorus, dissolved (mg/L as P) 50 <.05 .02 .06 24 .006 .03 .06 26 Phosphorus, ortho, dissolved 

(mg/L as P)

50 <.01 .02 .05 24 <.01 .02 .05 26 

Phosphorus, Total (mg/L as P) 50 .014 .05 .18 24 .02 .04 .08 26 Phosphorus, Total, load (kg/d) 45 5.7 48 260 22 234 677 9,150 23 Phosphorus, Total, yield (kg/d/mi2) 45 .02 .2 1 22 .04 .13 1.7 23 Iron, dissolved (μg/L as Fe) 51 90 230 850 24 40 60 90 26 Manganese, dissolved (μg/L as Mn) 51 38 81.2 211 24 3.9 12.8 18.4 26 

Sediment

Suspended sediment, in mg/L 51 1 6 27 24 1 3 63 25 

Table 5. Summary statistics for selected water-quality constituents in the three integrator sites in the New England Coastal Basins study area, 1998-2000--Continu[Min, minimum; Med, median; Max, maximum; μs/cm, microsiemens per centimeter at 25oC; oC, degrees Celsius; mg/L, milligrams per liter; <, less than; kg/d, kilogram

day per square mile; μg/L, micrograms per liter]

Water-quality constituent

Integrator sites

Charles River Kennebec River 

Sample 

size Min Med Max Sample size Min Med Max Sample size 
40 Water Quality of Selected Rivers in the New England Coastal Basins, 1998-2000

Appendix 1. Constituents analyzed in surface-water samples from fixed sites in the New England Coastal Basins study area, 1998-2000

[Dissolved oxygen, in milligrams per liter; pH standard units for laboratory and field; CaCO3, in milligrams per liter; alkalinity and bicarbonate, in 

milligrams per liter as HCO3; SP, specific conductance in microsiemens per centimeter at 25° C, temperature in degrees Celsius, ° C]

Laboratory analyses

Field measurements Major constituents Nutrients Suspended sediment

Specific conductance Dissolved solids Nitrogen Concentration

pH Major ions and metals Dissolved Sieve diameter (percent finer than 

0.0625 millimeter)

Temperature Calcium Dissolved ammonia (as N)

Dissolved oxygen Chloride Dissolved nitrite (as N)

Alkalinity Fluoride Dissolved nitrate (as N)

Bicarbonate Iron Dissolved ammonia and organic 

nitrogen (as N)

Magnesium Total ammonia and organic nitrogen 

(as N)

Manganese Phosphorus

Potassium Total

Silica Dissolved

Sodium Orthophosphorus (as P)

Sulfate Organic carbon

Suspended

Dissolved
Appendixes 1-3 41

Appendix 2. Pesticides and degradation products analyzed in surface-water samples from the Aberjona and Charles Rivers in 

the New England Coastal Basins study area, 1998-2000

[CAS, Chemical Abstract Services; No., number]

Compound Description CAS No. Compound Description CAS No.

2,6-Diethylalanine Degradation product 579-66-8 Malathion Insecticide 121-75-5

Acetochlor Herbicide 34256-82-1 Metolachlor Herbicide 51218-45-2

Alachlor Herbicide 15972-60-8 Metribuzin Herbicide 21087-64-9

alpha-HCH Degradation product 319-84-6 Molinate Herbicide 2212-67-1

Atrazine Herbicide 1912-24-9 Napropamide Herbicide 15299-99-7

Azinphos-methyl Insecticide 86-50-0 p,p'-DDE Degradation product 72-55-9

Benfluralin Herbicide 1861-40-1 Parathion Insecticide 56-38-2

Butylate Herbicide 2008-41-5 Parathion-methyl Insecticide 2998-00-0

Carbaryl Insecticide 63-25-2 Pebulate Herbicide 1114-71-2

Carbofuran Insecticide 1563-66-2 Pendimethalin Herbicide 40487-42-1

Chlorpyrifos Insecticide 2921-88-2 Phorate Insecticide 298-02-2

cis-Permethrin Insecticide 54774-45-7 Prometon Herbicide 1610-18-0

Cyanazine Herbicide 21725-46-2 Propachlor Herbicide 1918-16-7

Dacthal Herbicide 1861-32-1 Propanil Herbicide 709-98-8

Deethylatrazine Degradation product 6190-65-4 Propargite Insecticide 2312-35-8

Diazinon Insecticide 333-41-5 Propyzamide Herbicide 23950-58-5

Dieldrin Insecticide 60-57-1 Simazine Herbicide 122-34-9

Disulfoton Insecticide 298-04-4 Tebuthiuron Herbicide 34014-18-1

EPTC Herbicide 759-94-4 Terbacil Herbicide 5902-51-2

Ethalfluralin Herbicide 55283-68-6 Terbufos Insecticide 13071-79-9

Ethoprophos Insecticide 13194-48-4 Terbuthylazine Herbicide 5915-41-3

Fonofos Insecticide 944-22-9 Thiobencarb Herbicide 28249-77-6

Lindane Insecticide 58-89-9 Tri-allate Herbicide 2303-17-5

Linuron Herbicide 330-55-2 Trifluralin Herbicide 1582-09-8
42 Water Quality of Selected Rivers in the New England Coastal Basins, 1998-2000

Appendix 3. Volatile organic compounds analyzed in surface-water samples from the Aberjona and Charles Rivers in the New England Coastal Basins 

study area, 1998-2000

[CAS, Chemical Abstract Services; No., number]

Compound Primary use or 

source CAS No. Compound Primary use or source CAS No.

1,1,1,2-Tetrachloroethane Solvent 630-20-6 Carbon tetrachloride 

(tetrachloromethane)

Solvent 56-23-5

1,1,1-Trichloroethane (TCA) Solvent 71-55-6 Chlorobenzene Solvent 108-90-7

1,1,2,2-Tetrachloroethane Solvent 79-34-5 Chloroethane Solvent 75-00-3

1,1,2-Trichloroethane Solvent 79-00-5 Chloroform (trichloromethane) Disinfection 

by-product

67-66-3

1,1,2-Trichlorotrifluoroethane 

(CFC-113 or 1,1,3-Freon)

Refrigerant 76-13-1 Chloromethane (Methyl chloride) Refrigerant 74-87-3

1,1-Dichloroethane Solvent 75-34-3 Dibromochloromethane Disinfection 

by-product

124-48-1

1,1-Dichloroethylene Organic synthesis 75-35-4 Dibromomethane Solvent 74-95-3

1,1-Dichloropropene Organic synthesis 563-58-6 cis-1,2-Dichloroethylene Solvent 156-59-2

1,2,3,4-Tetramethylbenzene Hydrocarbon 488-23-3 cis-1,3-Dichloropropene Fumigant 10061-01-5

1,2,3,5-Tetramethylbenzene 

(isodurene)

Hydrocarbon 527-53-7 trans-1,2-Dichloroethylene Solvent 156-60-5

1,2,3-Trichlorobenzene Organic synthesis 87-61-6 trans-1,3-Dichloropropene Fumigant 10061-02-6

1,2,3-Trichloropropane Solvent 96-18-4 trans-1,4-Dichloro-2-butene Organic synthesis 110-57-6

1,2,3-Trimethylbenzene Gasoline 526-73-8 Dichlorodifluoromethane (CFC-12) Refrigerant 75-71-8

1,2,4-Trichlorobenzene Solvent 120-82-1 Diethyl ether Solvent 60-29-7

1,2,4-Trimethylbenzene Organic synthesis 95-63-6 Diisopropyl ether Gasoline 108-20-3

1,2-Dibromo-3-chloropropane Fumigant 96-12-8 Ethyl methacrylate Organic synthesis 97-63-2

1,2-Dibromoethane Solvent 106-93-4 Ethyl tert-butyl ether (ETBE) Gasoline 637-92-3

1,2-Dichlorobenzene Solvent 95-50-1 Ethylbenzene Gasoline 100-41-4

1,2-Dichloroethane Solvent 107-06-2 Hexachlorobutadiene Organic synthesis 87-68-3

1,2-Dichloropropane Solvent 78-87-5 Hexachloroethane Solvent 67-72-1

1,3,5-Trimethylbenzene Gasoline 108-67-8 Isopropyl-benzene Organic synthesis 98-82-8

1,3-Dichlorobenzene Solvent 541-73-1 m- and p-Xylene Gasoline 108-38-3

106-42-3

1,3-Dichloropropane Organic synthesis 142-28-9 Methyl acrylate Organic synthesis 96-33-3

1,4-Dichlorobenzene Fumigant 106-46-7 Methyl acrylonitrile Organic synthesis 126-98-7

2,2-Dichloropropane Organic synthesis 594-20-7 Methyl tert-butyl ether (MTBE) Gasoline 1634-04-4

Methyl ethyl ketone (2-Butanone) Solvent 78-93-3

Methyl iodide Organic synthesis 74-88-4

2-Chlorotoluene Solvent 95-49-8 Methyl methacrylate Organic synthesis 80-62-6

2-Hexanone Solvent 591-78-6 Methylene chloride 

(dichloromethane)

Solvent 75-09-2

3-Chloropropene Organic synthesis 107-05-1 Naphthalene Organic synthesis 91-20-3

4-Chlorotoluene Solvent 106-43-4 n-Propyl-benzene Solvent 103-65-1
Appendixes 1-3 43

4-Isopropyl-1-methylbenzene

(p-iso propyltoluene)

Organic synthesis 99-87-6 o-Ethyl toluene Hydrocarbon 611-14-3

4-Methyl-2-pentanone 

(methyl isobutyl ketone)

Solvent 108-10-1 o-Xylene Gasoline 95-47-6

Acetone Solvent 67-64-1 sec-Butylbenzene Organic synthesis 135-98-8

Acrylonitrile Organic synthesis 107-13-1 Styrene Organic synthesis 100-42-5

Benzene Gasoline 71-43-2 tert-Butylbenzene Organic synthesis 98-06-6

tert-Pentyl methyl ether (TAME) Organic synthesis 994-05-8

Bromobenzene Solvent 108-86-1 Tetrachloroethylene (PCE) Solvent 127-18-4

Bromochloromethane Organic synthesis 74-97-5 Tetrahydrofuran Solvent 109-99-9

Bromodichloromethane Disinfection 

by-product

75-27-4

Bromoethene Organic synthesis 593-60-2 Trichloroethylene (TCE) Solvent 79-01-6

Bromoform 

(tribromomethane)

Disinfection 

by-product

75-25-2 Trichlorofluoromethane (CFC-11) Refrigerant 75-69-4

Bromomethane

(methyl bromide)

Fumigant 74-83-9 Vinyl chloride Organic synthesis 75-01-4

Butylbenzene Organic synthesis 104-51-8

Carbon disulfide Organic synthesis 75-15-0

Appendix 3. Volatile organic compounds analyzed in surface-water samples from the Aberjona and Charles Rivers in the New England Coastal Basins 

study area, 1998-2000--Continued

[CAS, Chemical Abstract Services; No., number]

Compound Primary use or 

source CAS No. Compound Primary use or 

source CAS No.