Water Quality in the Connecticut, Housatonic, and Thames River Basins, Connecticut, Massachusetts, New Hampshire, New York, and Vermont, 1992Ð95 by S.P

Home , Hockanum River, Housatonic River, Norwalk River, Thames River (Ontario)

A COORDINATED EFFORT Coordination among agencies and organizations is an integral part of the NAWQA Program. We want to acknowledge the significant contribution by members of these organizations through their regular participation in the study liaison committee:

Federal and Interstate Organizations Local Agencies U.S. Fish and Wildlife Service Pioneer Valley Planning Commission U.S. Environmental Protection Agency Middlesex County Soil and Water Conservation District New England Interstate Water Pollution Control Universities Commission Connecticut River Joint River Commission (New University of Massachusetts Hampshire, Vermont) University of Connecticut State Agencies Private Organizations Connecticut Department of Environmental Protection Connecticut River Watershed Council Massachusetts Department of Environmental Protection Housatonic River Valley Association New Hampshire Department of Environmental Services Nature Conservancy Vermont Department of Environmental Conservation River Watch Network Much appreciation is extended to several U.S. Geological Survey employees for their significant contributions to this report: Robert F. Breault, Jonathan Morrison, John R. Mullaney, Peter A. Steeves, and Britt O. Stock. Special appreciation is extended to volunteer Peter Mitchell for his help and support.

Illustrations by Luis E. Menoyo; Rerendered by Mark V. Bonito Edited by Linda S. Rogers Hardcopy manuscript prepared by Luis E. Menoyo; PDF version prepared by Mark V. Bonito

Front cover: The Connecticut River near Sunderland, Massachusetts; photograph by Peter A. Steeves Back cover: (left) White River near West Hartford, Vermont; photograph by Britt O. Stock; (right) White River near West Hartford, Vermont; photograph by Britt O. Stock

FOR ADDITIONAL INFORMATION ON THE NATIONAL WATER-QUALITY ASSESSMENT (NAWQA) PROGRAM:

Connecticut, Housatonic, and Thames River Chief, NAWQA Program Basins Study Unit, contact: U.S. Geological Survey Water Resources Division District Chief 12201 Sunrise Valley Drive, M.S. 413 U.S. Geological Survey Reston, VA 20192 MA-RI District Office 10 Bearfoot Road, Suite 6 Northborough, MA 01532

Information on the NAWQA Program is also available on the Internet via the World Wide Web. You may connect to the NAWQA Home Page using the Universal Resources Locator (URL): http://wwwrvares.er.usgs.gov/nawqa/nawqa_home.html

The Connecticut, Housatonic, and Thames River Basins Study Unit’s Home Page can be accessed at URL: http://mass1.er.usgs.gov or http://ma.water.usgs.gov

Water Quality in the Connecticut, Housatonic, and Thames River Basins, Connecticut, Massachusetts, New Hampshire, New York, and Vermont, 1992Ð95 By S.P. Garabedian, J.F. Coles, S.J. Grady, E.C.T. Trench, and M.J. Zimmerman U.S. GEOLOGICAL SURVEY CIRCULAR 1155

CONTENTS

National Water-Quality Assessment Program...... 1 Summary of major issues and findings...... 2 Environmental setting and hydrologic conditions ...... 4 Major issues and findings: Contaminants in streambed sediments and fish tissue ...... 6 Nutrients in surface water...... 8 Pesticides in surface water...... 10 Pesticides in ground water ...... 12 Volatile organic compounds in ground water ...... 14 Nitrate in ground water ...... 16 Radon in ground water ...... 17

Water-quality conditions in a national context ...... 18 Study design and data collection...... 22 Summary of compound detections and concentrations ...... 24 References ...... 30 Glossary ...... 31

U.S. DEPARTMENT OF THE INTERIOR BRUCE BABBITT, Secretary

U.S. GEOLOGICAL SURVEY Thomas J. Casadevall, Acting Director

The use of firm, trade, and brand names in this report is for identification purposes only and does not constitute endorsement by the U.S. Government

Printed version 1998 PDF (web) version 2001

Free on application to the U.S. Geological Survey Branch of Information Services Box 25286 Denver, CO 80225Ð0286

Library of Congress Cataloging in Publications Data

Garabedian, Stephen P. Water Quality in the Connecticut, Housatonic, and Thames River Basins, Connecticut, Massachusetts, New Hampshire, New York, and Vermont, 1992-95 / by Stephen P. Garabedian. p. cm. -- (U.S. Geological Survey circular ; 1155) Includes bibliographical references. 1. Water quality--Connecticut River Watershed. 2.Water Quality-Housatonic River Watershed (Mass. and Conn.) 3. Water quality-Connecticut--Thames river watershed. I. Title. II. Series. TD223.15.g37 1998 363.739.42.0974--dc21 ISBN 0-607-89366-4

NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

Knowledge of the quality of the Nation's streams and aquifers is important because of the implications to human and aquatic health and because of the significant costs associated with decisions involving land and water management, conservation, and regulation. In 1991, the U.S. Congress appropriated funds for the U.S. Geological Survey (USGS) to begin the National Water-Quality Assessment (NAWQA) Program to help meet the continuing need for sound, scientific information on the areal extent of the water-quality problems, how these problems are changing with time, and an understanding of the effects of human actions and natural factors on water-quality conditions. The NAWQA Program is assessing the water-quality conditions of more than 50 of the Nation's largest river basins and aquifers, known as Study Units. Collectively, these Study Units cover about one-half of the United States and include sources of drinking water used by about 70 percent of the U.S. population. Comprehensive assessments of about one-third of the Study Units are ongoing at a given time. Each Study Unit is scheduled to be revisited every decade to evaluate changes in water- quality conditions. NAWQA assessments rely heavily on existing information collected by the USGS and many other agencies as well as the use of nationally consis- tent study designs and methods of sampling and analysis. Such consistency simulta- neously provides information about the status and trends in water-quality conditions in a particular stream or aquifer and, more importantly, provides the basis to make comparisons among watersheds and improve our understanding of the factors that affect water-quality conditions regionally and nationally. This report is intended to summarize major findings that emerged between 1992 and 1995 from the water-quality assessment of the Connecticut, Housatonic, and Thames River Basins Study Unit and to relate these findings to water-quality issues of regional and national concern. The information is primarily intended for those who are involved in water-resource management. Indeed, this report addresses many of the concerns raised by regulators, water-utility managers, industry representatives, and other scientists, engineers, public officials, and members of stakeholder groups who provided advice and input to the USGS during this NAWQA Study-Unit investigation. Yet, the information contained here may also interest those who simply wish to know more about the quality of water in the rivers and aquifers in the area where they live.

Robert M. Hirsch, Chief Hydrologist

U.S. Geological Survey Circular 1155 1

SUMMARY OF MAJOR ISSUES AND FINDINGS

Toxic contaminants have accumulated in some Study Unit streambed sediments and fish. Concentrations of polychlorinated biphenyls (PCBs) in streambed sediments and fish in the Housatonic River were among some of the highest detected in NAWQA Study Units across the Nation. Concentrations of trace elements and organic contaminants in streambed sediment and fish generally were highest in the southern part of the Study Unit (Massachusetts and Connecticut). Because of the presence of these contaminants, fish consumption advisories have been issued for a number of rivers and lakes throughout the Study Unit. These advisories recommend limiting the number of fish of certain species that should be consumed by people, particularly by children and pregnant women.

Nutrient (nitrogen and phosphorus) concentrations are a concern for surface-water quality. The large amount of nitrogen entering Long Island Sound from streams, precipitation, and coastal communities has stimulated algal blooms. Decay of the algae then produces low dissolved-oxygen conditions in the Sound, creating poor habitat for ﬁsh and other marine animals. Nitrogen and phosphorus concentrations are highest in urban streams, primarily because of wastewater discharges from sewage-treatment facilities.

Pesticides were frequently detected in Study Unit streams. The herbicides atrazine, metolachlor, prometon, and simazine, and the insecticides diazinon and carbaryl were the most frequently detected compounds. Concentrations of atrazine, metolachlor, and simazine were highest in surface water draining from agricultural areas. Concentrations of prometon, diazinon, and carbaryl were highest in surface water draining from urban areas. However, current drinking-water standards were not exceeded. None of the pesticides were detected at concentrations greater than the U.S. Environmental Protection Agency’s maximum contaminant level (MCL) or the health advisory limit (HAL), and few pesticide concentrations exceeded 1 microgram per liter (1 µg/L). Current drinking-water standards, however, do not include some detected pesticides (or breakdown products), and do not include consideration of more than one pesticide in the water. Thus, the actual health concern posed by these results is somewhat uncertain.

Several classes of contaminants were detected in ground water. These contaminants included pesticides, volatile organic compounds (VOCs), and nitrate. Twenty-four different pesticides (or their breakdown products) were detected in shallow ground water beneath the Study Unit. Atrazine, prometon, and simazine were the most commonly detected pesticides in ground water. VOCs were detected in 70 percent of the shallow ground-water samples collected in urban areas. Methyl tert- butyl ether (MTBE), a gasoline additive, was the most frequently detected VOC, and chloroform, a byproduct of water disinfection, was the second most frequently detected. Median nitrate concentrations in shallow ground water beneath agricultural ﬁelds (3.8 mg/L) were nearly 30 times higher than background concentrations (0.14 mg/L).

2 Water Quality in the Connecticut, Housatonic, and Thames River Basins, 1992-95

SUMMARY OF MAJOR ISSUES AND FINDINGS

Some contaminant MCLs were exeeded in ground water. The pesticides atrazine and ethylene dibromide were detected at concentrations greater than their MCLs in a few samples collected from agricultural areas. The VOCs—tetrachloroethene, trichloroethene, benzene, and naphthalene—exceeded their MCLs in some samples collected from urban areas. Nitrate concentrations exceeded the MCL in 15 percent of the samples of shallow ground water collected in agricultural areas.

Radon is present in ground water across the Study Unit.

Radon is a naturally occurring, colorless, odorless radioactive gas derived from VT. uranium. Exposure to radon has been recognized as a health risk, primarily as a cause of lung cancer. Radon concentrations exceeded the previously proposed limit of 300 picocuries per liter in 97 percent of water samples collected from bedrock supply wells, and in 88 percent of water samples collected from the shallow monitoring wells N.H. in the Study Unit. MASS.

CONN. R.I.

Quabbin Reservoir, which is within the Study Unit in central Massachusetts, supplies most of the drinking water for Boston, Massachusetts (photograph by Stephen Garabedian, U.S. Geological Survey).

U.S. Geological Survey Circular 1155 3

ENVIRONMENTAL SETTING AND HYDROLOGIC CONDITIONS The Connecticut, Housatonic, and 71û 73û Thames River Basins Study Unit, 15,760 square QUEBEC CANADA 72û 45û EXPLANATION miles in extent, includes eastern Vermont, UNITED STATES western New Hampshire, west-central AREA OF STUDY UNIT Massachusetts, nearly all of Connecticut, and VERMONT small parts of New York, Rhode Island, and the Mt. Province of Quebec, Canada. Altitudes in the NEWYORK Washington Study Unit range from sea level in coastal 44û Connecticut to 6,288 feet at the peak of Mount Washington in the White Mountains of New Hampshire. NEW HAMPSHIRE The population in the Study Unit is about 43û 4.5 million people, about 2 percent of the ATLANTIC OCEAN Nation’s population. Population density varies Connecticut River from the sparsely populated, rural agrarian and MASSACHUSETTS

NEW YORK Springfield wilderness areas of northern Vermont and New . Hampshire to the densely populated urban areas 42û Hartford RHODE of southwestern Connecticut and the south- Housatonic ✪ ISLAND River central part of the Connecticut River Valley. CONNECTICUT New Haven . Most of the area is forested undeveloped land, Bridgeport. agriculture covers about 12 percent of the total Thames River 41û area of the Study Unit, and urban areas cover LONG ISLAND SOUND 02040MILES about 8 percent of the Study Unit. All major 02040KILOMETERS Base from U.S. Geological Survey Digital Line Graphs, 1989 cities, including Hartford, Springﬁeld, Universal Transverse Mercator Bridgeport, and New Haven, are in the southern 1:100,000 part of the area. All streams in the Study Unit flow to Long Island Sound, with a Total freshwater use in the Study Unit combined drainage area of nearly 16,000 square miles. during 1990 was estimated to be about 2,300 Mgal/d (million gallons per day). The 71û 73û 72û dominant surface-water use is for thermoelectric QUEBEC CANADA 45û EXPLANATION power generation, and the next largest use is for UNITED STATES LAND USE—From Mitchell and public supply. Ground water supplied about others (1997) 12 percent (270 Mgal/d) of the freshwater used Urban VERMONT Agriculture in the Study Unit. Ground water is used Forest NEWYORK BOUNDARY OF MAJOR BASINS BOUNDARY OF STUDY UNIT primarily for public supply and self-supplied 44û domestic use. Discharges of treated sewage, amounting to about 520 Mgal/d, are released from 145 wastewater-treatment facilities, most NEW of which are in the densely populated southern HAMPSHIRE part of the area. 43û The climate in the Connecticut, ATLANTIC OCEAN

Housatonic, and Thames River Basins generally MASSACHUSETTS is temperate and humid. Mean annual NEW YORK precipitation averages about 43 inches over the 42û RHODE entire Study Unit but ranges from about ISLAND 34 inches at places in the northern end of the CONNECTICUT Connecticut River Valley to more than 65 inches in adjacent mountainous regions. In 02040 MILES 41û LONG ISLAND SOUND general, average precipitation is evenly 02040 KILOMETERS distributed throughout the year. Precipitation Base from U.S. Geological Survey Digital Line Graphs, 1989 generally was close to average during 1992-95, Universal Transverse Mercator with a slightly dry condition from March 1:100,000 through June 1995. Land use across the Study Unit varies from primarily forest in the northern areas to a mix of urban and agricultural uses to the south.

4 Water Quality in the Connecticut, Housatonic, and Thames River Basins, 1992-95.

ENVIRONMENTAL SETTING AND HYDROLOGIC CONDITIONS The Connecticut River is the principal river in the Study Unit, extending about 400 miles from its source in northern New Hampshire to the mouth at Old Saybrook, Connecticut, on Long Island Sound. The drainage area of the Connecticut River is 11,260 square miles, or about 72 percent of the Study Unit; average discharge at the mouth of the river is estimated to be 19,200 cubic feet per second. The Connecticut River is heavily regulated, with at least 125 reservoirs within the basin used for power generation and 16 flood-control reservoirs. Other major streams include the Housatonic and Thames Rivers, which together drain 3,420 square miles, or about 20 percent of the Study Unit. Average monthly discharge for an unregulated stream (that is, not dammed) show that peak streamflow generally is in late winter and early spring, but discharges in mid-1995 were uniformly lower than average because of below-average precipitation. The average annual discharge for the Connecticut River in 1995 was the sixth lowest discharge for 1930-95 owing to the dry conditions that year. The aquifers that yield the most water in the Study Unit are sand and gravel deposits within the glacial stratified drift that fills many of the valleys in the region. Water levels in wells are typically at their highest elevations in early spring and lowest elevations in late summer. Ground-water levels generally were close to average during 1992-95 but were slightly lower during mid-1995 as a result of the dry conditions that year.

2,500 10,000 GROUND WATER 100 White River at W. Hartford, Vermont 90 2,000 SURFACE WATER 8,000 AVERAGE MONTHLY DISCHARGE, 80 PERIOD OF RECORD (3,655) POPULATION SERVED, IN THOUSANDS 70 MONTHLY AVERAGE DISCHARGE 1,500 WATER YEARS 93-95 60 6,000 50 1,000 40 (3,655) 4,000 30 500 20 PERCENTAGE OF TOTAL (924) 10 FRESHWATER WITHDRAWALS 2,000 IN MILLION GALLONS PER DAY FRESHWATER WITHDRAWALS, 0 0

0 TOTAL DISCHARGE, IN CUBIC FEET PER SECOND 1992 1993 1994 1995 PUBLIC SUPPLY SUPPLY THERMO- ELECTRIC DOMESTIC

LIVESTOCK DATE INDUSTRIAL AND MINING COMMERCIAL

IRRIGATION AND Discharge in Study Unit streams without dams is About 80 percent of all freshwater used in the highest in the spring and lowest in late summer. Note Study Unit is from surface sources. Most of this the effect of decreased precipitation on discharge in water is used for cooling in thermoelectric power 1995. generation and for public supply.

4 36 10 Windsor Locks, Connecticut South Windsor, AVERAGE MONTHLY WATER 9 Connecticut LEVEL NOVEMBER 1966- SEPTEMBER 1995 AVERAGE MONTHLY PRECIPITATION (1961-90) 6 SW 64 34 8 MONTHLY PRECIPITATION (1992-95) WATER LEVEL DURING WATER YEARS 1992-95 7 8 32 6

4 10 30

3 12 28 PRECIPITATION, IN INCHES 2

1 44.14 inches average annual precipitation 14 26 WATER LEVEL, IN FEET ABOVE SEA LEVEL

0 WATER LEVEL, IN FEET BELOW LAND SURFACE 1992 1993 1994 1995 1992 1993 1994 1995 DATE DATE Precipitation was close to average during Ground-water levels vary seasonally and from year to 1992-95, except for slightly dry conditions in year. Note the effect of decreased precipitation on spring 1995. water levels in 1995.

U.S. Geological Survey Circular 1155 5

MAJOR ISSUES AND FINDINGS CONTAMINANTS IN STREAMBED SEDIMENTS AND FISH TISSUE Toxic contaminants have sediments from smaller streams that accumulated in some Study drain to Long Island Sound. Unit streambed sediments Concentrations of PCBs in streambed sediments and fish in the and fish Housatonic River are some of the Samples collected at selected highest for NAWQA Study Units in sites show that toxic contaminants the Nation; several of these have accumulated in streambed concentrations exceeded sediment and fish in many parts of 10,000 parts per billion. the Study Unit (Coles, 1996; Aquatic organisms can Breault and Harris, 1997). These are concentrate contaminants, and contaminants that do not easily adverse effects on bottom-dwelling Some fish collected for this study had dissolve in water but instead tend to organisms (for example, aquatic open sores from either injury or disease accumulate in streambed sediments insects, clams, crayfish) can be (photograph by Michael Turtora, U.S. and aquatic animals. The most related to elevated trace-element Geological Survey). common contaminants detected in and organic-compound bed sediment were the trace concentrations in streambed elements chromium, copper, lead, sediments (Breault and Harris, mercury, nickel, and zinc, and the 1997). Adverse effects can include organic compounds chlordane, decreased numbers of species and dichlorodiphenyltrichloroethane death of contaminant-sensitive (DDT), polychlorinated biphenyls species (Ecosystem Conservation (PCBs), and polycyclic aromatic Directorate, 1995). Trace elements hydrocarbons (PAHs). The most represent the most geographically commonly detected organic widespread concern to aquatic compounds detected in whole fish organisms, exceeding sediment- samples included chlordane, DDT quality guidelines over a wider (and its breakdown product DDE), geographical area than the organic and PCBs. These trace elements and compounds. However, some organic Spills and leaks of PCBs have led to organic compounds are on the U.S. compounds (chlordane and PCBs) contamination of streambed sediment Environmental Protection Agency’s pose the greatest biological concern and fish in many streams across the Priority Pollutant List and have in terms of exceeding sediment- Study Unit (photograph by Michael been given high priority in water- quality aquatic life guidelines; they Turtora, U.S. Geological Survey). quality monitoring and pollution are present at sufficiently high abatement programs. concentrations to cause severe Trace elements and organic effects at several locations in the human health concerns. U.S. compounds in streambed sediments Study Unit (see map at right). Environmental Protection Agency and fish generally were detected at Once bottom-dwelling organisms guidelines and U.S. Food and Drug lowest concentrations in the have become contaminated, they Administration standards have been northern forested drainage basins become a source of contaminants to established for contaminant and at highest concentrations in the fish. Many of the contaminants are concentrations in fish tissue for southern urban drainage basins readily stored in the fatty tissue of human consumption. The possible because of an increased number of fish where they tend to accumulate. risks to human health through the sources in the southern basins. In Fish-eating mammals and birds can consumption of contaminated fish addition, streams that drain large then consume the contaminated have resulted in advisories to basins typically had more frequent fish, and so pass contaminants up restrict the consumption of some detections of toxic contaminants the food chain. National Academy species of fish in the Study Unit. because these streams generally of Science and National Academy These advisories recommend drain large urban areas, providing of Engineering guidelines (1973) limiting the number of fish of more potential contaminant sources. for fish tissue, issued for the certain species that are consumed The highest percentages of trace- protection of fish-eating wildlife, by people, particularly by children element concentrations exceeding were exceeded at many sampling and pregnant women. Fish naturally occurring concentrations sites because of high concentrations consumption advisories now in were in samples collected from of PCBs, total chlordane, and effect include those issued for streambed sediments in the Thames dieldrin (see map at right). mercury contamination in River Basin. The highest Contaminants in fish tissue are a Connecticut (Department of percentages of organic-compound concern not only because of hazards Environmental Protection, 1994, detections were in streambed to wildlife but also because of 1996), Massachusetts (Department

6 Water Quality in the Connecticut, Housatonic, and Thames River Basins, 1992-95

MAJOR ISSUES AND FINDINGS CONTAMINANTS IN STREAMBED SEDIMENTS AND FISH TISSUE

71û EXPLANATION LAND USE—From Mitchell and others (1977)

73û 72û Urban Agriculture CANADA Forest 45û

STUDY UNIT BOUNDARY BED SEDIMENT SITES

VERMONT POTENTIAL FREQUENCY OF OCCURRENCE OF ADVERSE EFFECTS ON

MAINE BENTHIC ORGANISMS (Ecosystem Conservation, 1995)

Not detected Rare 44û Occasional Frequent Not sampled

TOTAL CHLORDANE LEAD TOTAL PCBs MERCURY

NEW HAMPSHIRE NATIONAL ACADEMY OF SCIENCE AND NATIONAL ACADEMY OF ENGINEERING GUIDELINES FOR ORGANOCHLORINES IN WHOLE FISH FOR THE PROTECTION OF NEW YORK FISH-EATING WILDLIFE

43 û Exceeds total PCB guideline

Exceeds total chlordane and dieldrin guideline

Sampled - No exceedance of guidelines

70û

ATLANTIC OCEAN MASSACHUSETTS 42û RHODE ISLAND

LONG ISLAND SOUND 0 10 20 30 40 50 MILES 41 û 0 10 20 30 40 50 KILOMETERS Base from U.S. Geological Survey Digital Line Graphs, 1989 Universal Transverse Mercator Projection, 1:100,000 scale

The potential for adverse effects on wildlife from toxic contaminants in either streambed sediment or fish is greatest in the southern part of the Study Unit.

of Environmental Protection, 1995), stream reaches because of Rivers in Connecticut (Connecticut New Hampshire (Department of contamination by PCB. These Department of Environmental Environmental Services, 1996) and stream reaches include lengths Protection, 1994). Information on Vermont (Department of along the Connecticut, Housatonic, fish consumption advisories is Environmental Conservation, Millers, and Otter Rivers in available in pamphlets distributed 1996). Other consumption Massachusetts, (Department of with fishing licenses and on signs advisories include those issued for Environmental Protection, 1995); posted along affected stream selected fish species from specific and the Connecticut and Housatonic reaches.

U.S. Geological Survey Circular 1155 7

MAJOR ISSUES AND FINDINGS NUTRIENTS IN SURFACE WATER Nutrient (nitrogen and contrast, nitrogen is typically the phosphorus) concentrations limiting nutrient for aquatic plant are a concern for surface- growth in saltwater, and excess water quality nitrogen can lead to algal blooms and low concentrations of dissolved Streams, lakes, and estuaries in oxygen in coastal waters. For the Study Unit have been adversely example, Long Island Sound affected by eutrophication caused ultimately receives all the water by above-background nutrient (and wastewater) from streams in concentrations, primarily the Study Unit, and algal blooms downstream from major urban created by excess nutrients have wastewater-treatment facilities. caused low concentrations of Algal blooms can occur in streams Nutrients are compounds dissolved oxygen and poor habitat downstream from wastewater- containing nitrogen and for ﬁsh and other marine animals in treatment facilities (Hockanum River at phosphorus. Nutrients in streams the sound (U.S. Environmental East Hartford, Connecticut. Photograph by Britt Stock, U.S. Geological Survey). are derived from natural sources and Protection Agency, 1997). human activities, including Land use and nutrient decaying plants, animal wastes, more than 10 times the median fertilizers, municipal and industrial concentrations in streams are concentrations for two urban wastewater, and atmospheric related streams without large upstream deposition. Many of these nutrient Nutrient concentrations are wastewater discharges. The median sources are quite large; for example, substantially higher in streams nutrient concentrations at the urban about 58 million pounds of nitrogen draining urban areas than in streams streams without large upstream and 11 million pounds of draining either agricultural or wastewater discharges were phosphorus are applied each year as forested areas in the Study Unit comparable to stream chemical fertilizer and manure in (Zimmerman and others, 1996). The concentrations in agricultural areas. the Study Unit . Although nitrogen median concentration of nitrate in The highest nitrate concentration and phosphorus are essential for water samples from urban streams (10 mg/L) measured in surface plant growth, high concentrations of was more than twice that of streams water during this study was these nutrients can cause in agricultural areas and more than collected from a station downstream eutrophication, a condition in which 10 times that in streams draining from a wastewater-treatment aquatic plant and algal growth is forested areas. Ammonia and facility. In contrast, the highest excessive. Decomposition of the phosphorus concentrations are concentration of nitrate detected in plants and algae reduces dissolved- much higher in urban water-quality an agricultural-area stream was oxygen concentrations in the water, samples than in samples from either creating poor habitat for ﬁsh and agricultural or forested areas. The 1.5

other aquatic animals. In addition, median phosphorus concentration MEDIAN NUTRIENT nitrogen in the form of ammonia for urban streams was three times CONCENTRATIONS 1.2 can be toxic to aquatic life, the that of streams in agricultural areas Nitrite plus nitrate (as N) toxicity level depending on the and nine times the median for Ammonia (as N)

temperature and pH of the water. streams in forested areas (see graph 0.9 Phosphorus (total as P) Nitrogen and phosphorus at right). compounds have different effects in Wastewater-treatment facilities freshwater and saltwater bodies. are major sources of nutrients in 0.6 Nitrogen concentrations are rarely surface water in urban areas. low enough to limit aquatic plant Nutrient concentrations at four growth in fresh-water, whereas urban-area streams sampled as part 0.3

phosphorus concentrations of the NAWQA program were IN MILLIGRAMS PER LITER CONCENTRATION,

generally are low enough to limit examined to determine the effect of 0 plant growth. Hence, excessive wastewater in these streams. URBAN AGRICULTURAL FORESTED (23 stations) (21 stations) (17 stations) aquatic plant growth and Median concentrations of ammonia, eutrophication in freshwater nitrate, and total phosphorus for two Concentrations of nitrogen and generally result from high streams with wastewater efﬂuent phosphorus are substantially higher in phosphorus concentrations greater than 10 percent of the ﬂow streams draining urban areas than in streams draining either agricultural or (typically greater than 0.1 mg/L). In at the sampling site were from 2 to forested areas.

8 Water Quality in the Connecticut, Housatonic, and Thames River Basins, 1992-95

MAJOR ISSUES AND FINDINGS NUTRIENTS IN SURFACE WATER one-half the highest concentration concentrations, resulting primarily total amount of nutrients detected in an urban-area stream. from improved wastewater- (particularly nitrogen) discharged to treatment processes, which convert Long Island Sound is still Nutrient concentrations are ammonia to nitrate (Trench, 1996). considered an environmental changing with time Decreases in total phosphorus concern (U.S. Environmental Nitrate concentrations in streams concentrations also are likely due to Protection Agency, 1997). improvements in wastewater commonly increased during 1980- The MCL for nitrate (10 mg/L as 92, whereas ammonia and total treatment and to the elimination or phosphorus concentrations reduction of phosphate in N) was rarely exceeded in the Study commonly decreased (Zimmerman, detergents. Although more effective Unit, indicating that nutrient 1997). Decreases in ammonia wastewater treatment has improved concentrations generally are not a concentrations were generally surface-water-quality conditions in concern for surface-water supplies associated with increases in nitrate many parts of the Study Unit, the used for drinking water.

73û 72û 73û 72û 3 3 42û 6 5 42û 6 5 9 9 1 1 7 7 8 2 8 2 12 4 12 4 10 10 14 11 14 11 13 13 15 15

16 16

41û 41û TTotalotal NitrNitrogenogen Nitrate-NitrNitrate-Nitrogenogen

3 3 42û 6 5 42û 6 5 9 9 1 1 7 7 8 2 8 2 12 4 12 4 10 10 14 11 14 11 13 13 15 15

16 16

41û 41û Ammonia-NitrAmmonia-Nitrogenogen TTotalotal Phosphorus

EXPLANATION Drainage Drainage Map Map LAND USE Station name basin area Station name basin area No. No. Urban 0 20 MI (square miles) (square miles) Agriculture 0 20 KM 1wW0illimantic River at Merro 94. 9eF7armington River at Tariffvill 57 Forest 2mS8hetucket River at South Windha 40 1n0 S0almon River near East Hampto 10 GAGING STATION AND NUMBER 3gQ5uinebaug River at Quinebau 15 1d1 Q5uinnipiac River at Wallingfor 11 4yQ3uinebaug River at Jewett Cit 71 1d2 H2ousatonic River near New Milfor 1,02 Upward or downward trend 5 Connecticut River at Thompsonville9,66 0 1n3 H4ousatonic River at Stevenso 1,54 916—arrowhead indicates location of gaging station 6nS2till River at Riverto 86. 1s4 N0augatuck River at Beacon Fall 26 14 No trend—dot indicates 7eF8armington River at Unionvill 37 1g5 S0augatuck River near Reddin 21. location of gaging station 8nP2equabuck River at Farmingto 57. 1k6 N0orwalk River at Winnipau 33.

Concentrations of nutrients in Connecticut from 1980 to 1992 were generally unchanged for total nitrogen, increased for nitrate, and decreased for ammonia and phosphorus. These changes were primarily the result of more effective wastewater treatment, which has significantly improved the water quality in streams over this period (Zimmerman, 1997).

U.S. Geological Survey Circular 1155 9

MAJOR ISSUES AND FINDINGS PESTICIDES IN SURFACE WATER

3.5 Pesticides were frequently prometon is a broad-band URBAN (nonselective) weed control detected in Study Unit 3.0 commonly used along highways streams and railroads. Other commonly 2.5 detected pesticides included the 2.0 Nationally, more than 1.1 billion insecticides diazinon (for crops and pounds of pesticides are applied home applications) and carbaryl 1.5 AGRICULTURAL each year to control rodents, (for crops and other plants). Each 1.0 insects and grubs, weeds, fungi, of these pesticides was detected at IN MICROGRAMS PER LITER IN MICROGRAMS 0.5 and other pests in urban centers, 20 percent or more of the stream FORESTED 0 suburbs, rural communities, and sites. MAXIMUM PESTICIDE CONCENTRATION, farms. The occurrence and INTEGRATOR distribution of pesticides in water Land use and pesticide EXPLANATION draining from various land-use concentrations in streams PESTICIDES DETECTED - Number in parenthesis is the types were investigated as part of MCL or HAL in micrograms per liter for each pesticide. are related * indicates pesticide exceeded the noted the NAWQA program by collecting aquatic-life criteria. and analyzing samples from 56 Herbicides Insecticides Different numbers and types of Atrazine (3) Carbaryl (700)(*0.02) stream sites across the Study Unit. Metolachlor (100) Diazinon (0.6)(*0.009) Streams were sampled after spring pesticides were detected in samples Prometon (100) applications of pesticides and collected from streams draining Simazine (4) during low-ﬂow conditions (late urban, agricultural, and forested areas, and streams draining large The concentrations of most common summer). herbicides were highest in streams The pesticides most frequently basin areas. Twenty-seven draining agricultural areas in the Study detected in streams in the Study pesticides or breakdown products Unit, whereas concentrations of most Unit include the herbicides were detected in samples collected common insecticides were highest in atrazine, metolachlor, simazine, in urban areas. Diazinon was the urban-area streams. and prometon. Atrazine and most commonly detected pesticide metolachlor are used for selective in urban stream sites; it was weed control, typically in the detected in one or more samples at the samples. Prometon was cultivation of feed corn, which is 92 percent of these sites. Other detected in more than 90 percent of grown in New England primarily commonly detected pesticides at the Norwalk River samples. The for dairy cattle. Simazine is used urban streams were atrazine and highest prometon concentration for weed control in agricultural and prometon. The maximum was 0.14 µg/L, about 1,000 times urban areas (lawn care), and concentrations of carbaryl, lower than the MCL for this diazinon, and prometon were compound. Other commonly 100 detected at urban streams, but these PESTICIDES DETECTED 90 detected pesticides included Herbicides Insecticides concentrations did not exceed their Atrazine Carbaryl simazine, carbaryl, metolachlor, 80 Metolachlor Diazinon HALs. However, carbaryl and Prometon diazinon concentrations did exceed and DCPA (another herbicide); 70 Simazine these pesticides were detected in 60 the aquatic-life criteria in samples collected from a stream draining an more than 20 percent of the 50 urban area. samples collected at this site. 40 A study was conducted at a site Fourteen pesticides or 30 on the Norwalk River (Winnipauk, breakdown products were detected SURFACE-WATER STATION SURFACE-WATER 20 Connecticut) to investigate in streams draining agricultural

10 pesticide concentrations in a basins in the Study Unit. Three PERCENTAGE OF PESTICIDE DETECTIONS AT PERCENTAGE 0 stream draining an urban/suburban herbicides—atrazine, metolachlor, setting. Samples were collected and simazine—were the most weekly from March through frequently detected pesticides at TOTAL URBAN

(7 stations) October and monthly from agricultural stream sites; the FORESTED (20 stations) (56 stations) (13 stations) (16 stations) INTEGRATOR AGRICULTURAL November through February maximum concentrations for these The proportion and variety of pesticide during 1993 and 1994, for a total of compounds were in samples detections at stream sites differed 59 pesticide samples in this period. collected at agricultural sites. considerably among land-use types Twenty-two pesticides or Atrazine was detected at 88 percent across the Study Unit. Although the highest proportion of detections were in breakdown products were detected of the agricultural sites, and was high pesticide use areas, pesticides at the Norwalk River site; however, the most commonly detected were still detected in forested only prometon and atrazine were pesticide for the study overall. (background) areas. detected in more than 50 percent of Although none of the atrazine

10 Water Quality in the Connecticut, Housatonic, and Thames River Basins, 1992-95

MAJOR ISSUES AND FINDINGS PESTICIDES IN SURFACE WATER concentrations exceeded the MCL, 71û atrazine was frequently detected in 73û 72û combination with other pesticides EXPLANATION CANADA 45û and with desethylatrazine, a NUMBER OF PESTICIDES DETECTED breakdown product of atrazine. 0 Pesticide detections generally 1 to 4 were fewer in streams draining VERMONT MAINE 5 or more forested basins than in streams draining urban and agricultural LAND-USE TYPE 44 areas, and pesticide concentrations û Mixture of land use (integrator) also were low in streams in Agriculture forested basins. The greatest Urban NEW HAMPSHIRE variety of pesticides generally was Forest detected in samples collected from large rivers (see map at right). The BOUNDARY OF STUDY UNIT

NEW YORK most commonly detected 43û pesticides in samples collected from large rivers were atrazine and metolachlor, with mixtures of several pesticides common. 70û

ATLANTIC OCEAN Although many pesticides were NEW YORK MASSACHUSETTS 42û detected in samples collected from RHODE large rivers, the concentrations ISLAND were low, and none of the CONNECTICUT concentrations were maximums for these compounds for this study. These results reﬂect the mixed LONG ISLAND SOUND nature of the upstream land use in 41û Norwalk River larger basins and the dilution of 0 10 20 30 40 50 MILES

Base from U.S. Geological Survey Digital Line Graphs, 1989 0 10 20 30 40 50 KILOMETERS pesticide concentrations in these Universal Transverse Mercator rivers by large ﬂows. Rivers with 1:100,000 scale the highest percentage of pesticide The greatest variety of pesticide detections at stream sites generally was in the detections generally were in the southern part of the Study Unit, where there are large urban areas and agricultural southern part of the Study Unit, activity is most intensive. where population density is greatest and agricultural activity generally is most intensive. Current drinking-water standards were not exceeded. None of the pesticides were detected at concentrations greater than the U.S. Environmental Protection Agency’s MCL or HAL for the compound, and few pesticide concentrations exceeded 1 µg/L. Current drinking-water standards, however, do not include some of the detected pesticides (or breakdown products) and do not include consideration of more than one pesticide in the water. Thus, there is some uncertainty in the actual health concern posed by Pesticides, particularly herbicides, were frequently detected in water draining from these results. agricultural areas (photograph by Stephen Grady, U.S. Geological Survey).

U.S. Geological Survey Circular 1155 11

MAJOR ISSUES AND FINDINGS PESTICIDES IN GROUND WATER Pesticides were frequently desethylatrazine, prometon, and detected in ground water simazine alone accounted for 72 percent of all pesticide Twenty-four pesticide compounds detections. Metolachlor also was or breakdown products were frequently detected, comprising detected in shallow monitoring wells 9 percent of the total. Carbaryl was across the Study Unit (Grady and the most frequently detected Mullaney, 1998). Although insecticide. The only other pesticides were frequently detected, insecticide detected in more than the concentrations generally were two wells was DDE, a breakdown low, and more than 75 percent of all product of DDT. pesticide detections reported in this A few of the most heavily applied study were at trace-level pesticides in the Study Unit were not concentrations of less than 0.1 µg/L. detected in shallow ground-water Sampling ground water at a monitoring The pesticides (or breakdown samples, for example, alachlor and well with an electric submersible pump products) were detected in water chlorpyrifos. Important factors in the (photograph by Stephen Garabedian, samples collected from 103 mobility and detection of a pesticide U.S. Geological Survey). monitoring wells in the Study Unit. include solubility (the compound’s The depths of these monitoring ability to dissolve in water), that degrade quickly also are less wells ranged from 7 to 54 ft below persistence (how slowly it breaks likely to be detected in ground water. land surface and generally were down), and the soil characteristics in Pesticides applied in areas of ﬁne- screened in the upper 10 ft of the the area where it is applied. Low grained soils will move slowly aquifer. Herbicides comprised 90 solubility pesticides tend to stay through these materials and make it percent of the pesticide detections in adsorbed to the soil and thus do not less likely that the pesticide will be these wells. Atrazine, leach into ground water. Pesticides detected in ground water. Thus, the

20 FORESTED (23 samples)

AGRICULTURAL (40 samples) HERBICIDE 60 INSECTICIDE

0 PERCENTAGE OF WELLS WITH DETECTIONS 40 URBAN (40 samples)

DDE DCPA Terbacil Triallate Atrazine Simazine Trifluralin Bromacil Propanil Carbaryl p,p' Benfluralin PrometonPropargite Metribuzin Metolachlor Carbofuran Permethrin DichlobenilDichlorpropEthalfluralin Tebuthiuron Napropamide Desethylatrazine Aldicarb sulfoxide Atrazine, a herbicide used in the cultivation of corn, and its breakdown product desethylatrazine, were the most commonly detected pesticide compounds in ground water in the Study Unit.

12 Water Quality in the Connecticut, Housatonic, and Thames River Basins, 1992-95

MAJOR ISSUES AND FINDINGS PESTICIDES IN GROUND WATER probability that a pesticide will be wells in urban areas and 48 percent Pesticide concentrations generally detected in shallow ground water is of water samples from wells in were highest in water samples from highest for pesticides that are highly forested areas. Of the 24 compounds wells in agricultural areas; more soluble in water, relatively stable, detected in samples from all well than 33 percent of the concentrations and applied in large amounts to types, 19 were detected in samples were greater than or equal to highly permeable soils. An from agricultural wells, including 12 0.1 µg/L. In contrast, most of the additional factor is the sensitivity of compounds that were detected pesticide detections in ground water the chemical analysis for the exclusively in these wells. Atrazine, pesticide; this varies depending on beneath urban and forested areas desethylatrazine, and metolachlor were at concentrations less than the actual concentration of the were detected in water samples from µ pesticide (low concentrations agricultural wells more often than in 0.1 g/L. Only two pesticides, generally are less likely to be samples from wells in forested or atrazine and ethylene dibromide detected), and the characteristics urban areas. More than 70 percent of (EDB), were detected at inherent to the analytical method the agricultural wells contained concentrations that exceeded their used for each pesticide. either atrazine and or MCLs (although several detected desethylatrazine, and metolachlor pesticides do not have MCLs). An Land use and pesticide was detected in 28 percent of these atrazine concentration of 3.6 µg/L in concentrations in ground wells. More than 50 percent of the a sample from a cornﬁeld well was water are related water samples from agricultural slightly greater than the MCL of wells contained two or more 3.0 µg/L. An EDB concentration of A comparison of pesticide pesticides. 1.4 µg/L in a sample from an area of detection frequencies by land-use ornamental plant cultivation was category indicates that the In contrast to other herbicides, substantially greater than the MCL proportions of wells with pesticide prometon was detected primarily in µ detections differed among the three water samples from wells in urban of 0.05 g/L. The area of ornamental major land-use categories. Water areas, with about 33 percent of these plant cultivation had recently been in samples from 80 percent of samples containing this compound. tobacco production. Although agricultural wells contained at least Similarly, simazine was most banned for use now, EDB was used one pesticide as compared to frequently detected in water samples as a pesticide in the cultivation of 60 percent of the water samples from from wells in urban areas. tobacco in the Study Unit.

Some of the most productive farms in the Study Unit are on the Connecticut River flood plain (photograph by Stephen Garabedian, U.S. Geological Survey).

U.S. Geological Survey Circular 1155 13

MAJOR ISSUES AND FINDINGS VOLATILE ORGANIC COMPOUNDS IN GROUND WATER VOCs were also frequently detected in ground water EXPLANATION URBAN LAND USE Volatile organic compounds are frequently detected in shallow MONITORING WELLS ground water beneath urban areas in VOCs not detected VOCs detected the Study Unit. These compounds are used in paints, adhesives, petro- WATER-SUPPLY WELLS leum products (fuels), pharmaceuti- VOCs not detected cals, refrigerants, solvents, hydraulic VOCs detected fluids, dry cleaning agents, and some Manchester pesticides, and they can contami- nate ground water by way of industrial use and release, leaking underground fuel tanks and pipe- lines, accidental surface spills and leaks, and infiltration of runoff from paved urban areas. Twenty-five different VOCs were Hamden detected in water from wells sampled in the Study Unit (Grady, 1997). The gasoline additive MTBE was detected in about 25 percent of all wells and was the most commonly detected compound. Chloro- form (a trihalomethane) can form during disinfection of drinking- water supplies and was the second most frequently detected compound. Chloroform was present in a little less than 25 percent of all wells. Tetrachloroethene and trichloroethene, solvents commonly used in industrial and commercial activi- Volatile organic compounds were detected in ground water most ties (for example as degreasers), also frequently in the urban areas of the southern part of the Study Unit. were commonly detected in wells in the Study Unit. 25 Land use and VOC HALOGENATED ALKANE concentrations in ground 20 HALOGENATED ALKENE water are related ETHER Of the 133 wells sampled for 15 ALKYLATED BENZENE VOCs, most of the 61 wells with HALOGENATED BENZENE VOC detections were in the southern 10 part of the Study Unit (Grady, 1997). VOCs were most commonly 5 detected in samples from wells in urban areas, with 70 percent of mon- 0 itoring wells in urban areas contain- PERCENTAGE OF WELLS WITH DETECTIONS ing one or more compounds. Toluene Benzene Xylenes Choroform Twenty-three of the 25 VOCs -butyl ether Naphthalene -Butylbenzene-Butylbenzene Ethylbenzene tert Trichloroethene Bromobenzenen -Propylbenzene present in ground-water samples -Isopropyltoluenesec Isopropylbenzenen Tetrachloroethene 1,1-DichloroethaneMethylene chloride p -1,2-Dichloroethene Carbon tetrachloride were detected at least once in moni- cis 1,1,1-Trichloroethane Methyl 1,2,4-TrimethylbenzeneBromodichloromethane 1,3,5-Trimethylbenzene toring wells in urban areas, and 19 of Dichlorodifluoromethane 1,2-Dibromoethane (EDB) the 23 compounds were detected Methyl tert-butyl ether and chloroform were the most frequently detected volatile exclusively or most frequently in organic compounds.

14 Water Quality in the Connecticut, Housatonic, and Thames River Basins, 1992-95

MAJOR ISSUES AND FINDINGS VOLATILE ORGANIC COMPOUNDS IN GROUND WATER

wells in urban areas. VOCs were NUMBER OF WELLS SAMPLED detected in 37 percent of the samples (22) (24) (57)(15) (15) collected from monitoring wells in 80 agricultural areas; nine compounds were detected, due in part to the use Urban of some VOCs (EDB and naphtha- Some urban land use lene) as pesticides. The fewest num- 60 ber of VOC detections (9 percent) were in samples from monitoring wells in forested areas, and only three compounds were detected. 40 Agricultural VOCs also were detected in domestic water-supply wells drilled into bedrock; most in wells within a 0.25 mile distance of an urban 20 land-use area. No urban land use Although most VOC concentra- Forest tions measured in ground-water

samples were low, concentrations PERCENTAGE OF WELLS WITH VOC DETECTIONS 0 µ were as high as 300 g/L. High con- MONITORING WATER-SUPPLY centrations of tetrachlorethane WELLS WELLS (250 µg/L), trichloroethene µ µ The proportion of detections of volatile organic compounds was highest in urban (63 g/L), benzene (73 g/L), and areas, regardless of well type. total xylenes (300 µg/L) were detected in samples from three monitoring wells in an urban area; these MTBE and its effect on urban areas but was undetected or VOC concentrations are indicative ground-water quality rarely detected in ground water of nearby point sources. Most of the beneath forested and agricultural The Clean Air Act Amendments areas. Most MTBE detections VOC detections (64 percent), how- of 1990 mandated use of oxygenated (69 percent) have been in shallow ever, were at concentrations less monitoring wells that are within µ or reformulated gasoline in speciﬁc than 1.0 g/L; these concentrations parts of the United States where car- 0.25 mile of gasoline stations. All are more indicative of nonpoint bon monoxide and ozone concentra- MTBE concentrations were less than sources. tions do not meet air-quality the current U.S. Environmental Volatile organic compound con- standards. As a result, MTBE is Protection Agency drinking-water tamination of drinking-water sup- added to gasoline as an oxygenate health advisory (U.S. Environmental plies is a health concern because Protection Agency, 1996) for this across the Northeastern United compound (20 to 40 µg/L). many of these compounds are toxic States, including most of New and are known or suspected human England, to help meet these stan- carcinogens. Concentrations of ben- dards. As a consequence of its exten- zene, EDB, naphthalene, tetrachlo- sive use and persistence, MTBE was roethene, and trichloroethene the most commonly detected VOC in exceeded their MCLs or HALs in ground water in the Study Unit. samples from ﬁve monitoring wells; MTBE was detected in water sam- all but one of which were in urban ples in 33 of the 133 wells sampled, areas. Public-supply wells are com- at concentrations ranging from pleted in several of the same aquifers 0.2 to 5.8 µg/L. Most of the that were sampled in this study. detectable MTBE concentrations Therefore, these study results indi- were in water samples from wells in cate that high VOC concentrations Connecticut and Massachusetts, are of potential health concern with where use of oxygenated or refor- regard to drinking-water supplies, mulated gasoline is required. Urban areas include many possible particularly for ground water in sources of volatile organic compounds, The presence of MTBE in ground including gasoline stations, commercial urban areas, where10 percent of the water appears to be related to urban establishments, and manufacturing monitoring wells exceeded a VOC land use, as it was detected in nearly operations (photograph by Stephen MCL. 50 percent of the wells sampled in Grady, U.S. Geological Survey).

U.S. Geological Survey Circular 1155 15

MAJOR ISSUES AND FINDINGS NITRATE IN GROUND WATER

Nitrate concentrations can be signiﬁcantly lower than the maxi- 5.0 a ground-water quality mum concentration in ground water 4.5 concern beneath agricultural areas (22 mg/L). Nitrate concentrations in 4.0 The widespread application of ground-water samples from urban chemical fertilizers, manure, and areas are substantially higher than 3.5 sewage sludge to some agricultural those in samples from forested areas, ﬁelds has caused high nitrate con- but less than those in agricultural 3.0 centrations in shallow ground water areas. The median concentration of 2.5 in the Study Unit (Grady and nitrate in ground-water samples Mullaney, 1998). from forested areas is only 0.14 2.0

Reported total applications of mg/L; this represents the expected 1.5 nitrogen in chemical fertilizer and natural background concentration of manure are estimated to be about nitrate in ground water. Only two 1.0 58 million pounds in the Study Unit. samples from wells in forested areas Much of the nitrogen is applied to contained more than 1.0 mg/L of 0.5 agricultural ﬁelds, but fertilizers also nitrate, and these samples were from

MEDIAN NITRITE PLUS NITRATE CONCENTRATION (MG/L) 0 are commonly used on lawns and sites where transport of nitrogen Agriculture Urban Forest turf in urban and suburban areas. from nearby agricultural fields was LAND-USE CATEGORY Other sources of nitrogen in urban possible. Nitrate concentrations were highest in areas are from septic system and Drinking water that contains shallow ground water beneath sanitary-sewer effluents, domestic nitrate concentrations that exceed agricultural areas. animal wastes, and infiltration of the MCL (10 mg/L) is a health con- runoff from urban streets and cern, particularly for infants. In this drinking water, many of the aquifers parking lots. Significant amounts of study, 15 percent of the water col- that were sampled are used for nitrogen also are deposited by lected from wells in agricultural drinking-water supplies. These precipitation in the Study Unit, with areas yielded water with nitrate con- results indicate a potential health 2,200 to 2,400 kilograms per year centrations that exceeded the MCL. concern, particularly for shallow per square mile estimated for most Although the wells sampled as part wells used for rural domestic supply of the area. Although nitrogen is of this study are not used for in agricultural areas. deposited and applied in various forms, the most common form of nitrogen in ground water is nitrate. Concentrations of nitrate were measured in samples from 120 monitoring wells across the Study Unit. Results from this investigation showed nitrogen concentrations in samples from wells in agricultural areas were significantly higher than in samples collected from wells in either urban or forested areas. The median nitrate concentration in samples from agricultural wells is 3.8 mg/L, which is nearly 30 times the median concentration for wells in forested areas (0.14 mg/L) and more than 3 times the median concentration in urban areas (1.1 mg/L). Nitrate concentrations in ground water in urban areas generally are low because average nitrogen fertilizer application rates are less than the fertilizer and manure applications in agricultural areas. The high- Fertilizers are often heavily applied to row crops like corn and, if soils are est nitrate concentration for urban permeable, cause higher nitrate concentrations in ground water beneath the fields ground water is 9.7 mg/L, (photograph by Stephen Grady, U.S. Geological Survey).

16 Water Quality in the Connecticut, Housatonic, and Thames River Basins, 1992-95

MAJOR ISSUES AND FINDINGS RADON IN GROUND WATER Radon is present in ground in the radioactive decay series that activity was high in the water sam- water across the Study Unit leads to the formation of radon gas, ples from the bedrock-supply wells but the distribution is not even. (2,150 pCi/L); 97 percent of these Almost all monitoring and supply Some types of igneous and meta- samples exceeded the previously wells sampled as part of this study morphic rocks (granites, for exam- proposed limit. Median radon activ- exceeded the previously proposed ple) have high uranium content and ity was low for water samples from limit for radon. are frequently associated with high shallow monitoring wells in strati- Radon is a naturally occurring, radon activities. After radon gas is fied-drift aquifers (520 pCi/L), but colorless, odorless radioactive gas, produced in the rock, some of it can 88 percent of samples from these which can be a health risk for lung become dissolved in the water pass- wells still exceeded the previously cancer when people are exposed to ing through the rock, and the water proposed limit. Water from a few high concentrations over an (with the radon in it) may be shallow monitoring wells exceeded extended period of time. Exposures pumped from a well and used in a 1,000 pCi/L, but radon activities of to radon gas occur primarily through home. Use of the water for washing, most samples (88 percent) from the movement of soil gas into a cooking, or drinking exposes people crystalline bedrock wells were home, but radon also can enter to the radon gas, creating a health greater than 1,000 pCi/L and sam- homes from ground water pumped risk. ples from two bedrock wells from private wells. Radon concen- Analyses of ground-water sam- exceeded 10,000 pCi/L. Although trations are reported as a measure of ples collected in the Study Unit indi- these radon levels in bedrock wells its radioactivity, an “activity” in pic- cate that almost all water samples are high in comparison to levels in ocuries per liter. The previously pro- (94 percent of samples from 47 other NAWQA Study Units (see posed limit on the activity of radon wells) exceeded the previously pro- Water-Quality Conditions in a gas was 300 picocuries per liter of posed limit. Two types of wells were National Context), they are similar water (pCi/L) (U.S. Environmental sampled for radon as part of this to ranges of radon levels reported for Protection Agency, 1996). study—bedrock supply wells and ground water from bedrock in other All rocks in the Study Unit con- shallow monitoring wells in strati- areas of the United States (Brill, tain some uranium, the first element fied-drift aquifers. Median radon 1994).

Almost all of the sampled bedrock wells, like the one pictured above, had radon concentrations that exceeded the previously proposed limit (photograph by Stephen Garabedian, U.S. Geological Survey).

U.S. Geological Survey Circular 1155 17

WATER-QUALITY CONDITIONS IN A NATIONAL CONTEXT Comparison of Stream Quality in the Connecticut, Housatonic, and Thames River Basins with Nationwide NAWQA Findings Water-quality characteristics were evaluated for stream sites in each NAWQA Study Unit. Summary scores for each characteristic were computed for all sites that had adequate data. Scores for each site in the Connecticut, Housatonic, and Thames River Basins were compared with scores for all sites sampled in the 20 NAWQA Study Units during 1992Ð95. Results are summarized by percentiles; higher percentile values generally indicate poorer quality compared with other NAWQA sites. Water-quality conditions at each site also are compared to established criteria for protection of aquatic life. Applicable criteria are limited to nutrients and pesticides in water, and semivolatile organic compounds, organochlorine pesticides and PCBs in sediment. (Methods used to compute rankings and evaluate aquatic-life criteria are described by Gilliom and others, in press.)

EXPLANATION Ranking of stream quality relative to all TRACE ELEMENTS in bed sediment NAWQA stream sites — Darker colored circles generally indicate poorer quality. Trace elements in sediment were Bold outline of circle indicates one or more high compared to other NAWQA aquatic life criteria were exceeded. Study Units. Many sites contained at least one trace element that Greater than the 75th percentile exceeded aquatic life criteria. (among the highest 25 percent Though some trace elements occur of NAWQA stream sites) naturally in soils, sites shaded

darkest show the effects of point

Between the median and the 75th percentile e v

i and nonpoint waste-discharge R sources of these elements.

Between the 25th percentile and the median

u Less than the 25th percentile c i

(among the lowest 25 percent n o of NAWQA stream sites) C

SEMIVOLATILE ORGANIC COMPOUNDS in bed sediment Several sites sampled for SVOCs were ranked among some of the highest of the NAWQA Study Units. These compounds are commonly associated with the byproducts of fuel combustion. Several sites exceeded the aquatic life criteria for SVOCs.

ORGANOCHLORINE PESTICIDES and PCBs r r

e e

v v

i i R R in bed sediment and biological tissue Concentrations of PCBs and organochlorine compounds were among some of the highest of the NAWQA

t t

u u

c c i i

t t

c c

e Study Units. Organochlorine compound n n

n n

o o C and PCB concentrations exceeded C aquatic life criteria at several sites. Although most of these compounds are presently banned, they still persist.

18 Water Quality in the Connecticut, Housatonic, and Thames River Basins, 1992-95

WATER-QUALITY CONDITIONS IN A NATIONAL CONTEXT

CONCLUSIONS

In the Connecticut, Housatonic, and Thames River Basins, compared to other NAWQA Study Units: ¥ High concentrations of nutrients, primarily from wastewater-treatment facilities in urban areas, are causing eutrophication in some lakes, streams, and ponds. ¥ Pesticide concentrations in water are relatively low. Guidelines for the protection NUTRIENTS in water of aquatic life are exceeded by pesticide Nutrient levels downstream from urban concentrations only infrequently. and agricultural areas were among some ¥ Concentrations of PCBs and of the highest of the NAWQA Study organochlorine pesticides in bed sediment Units. Nutrient concentrations in some and fish are among the highest for NAWQA Study Units, and concentrations exceeded

r streams were high enough to contribute e

v i R to eutrophication and low dissolved- guidelines for the protection of wildlife in several places. oxygen conditions, particularly in lakes and estuaries downstream from major ¥ Degradation of stream habitat and fish urban areas. communities, as indicated at the limited

t u number of NAWQA stream sites, is c i

o moderate in the Study Unit. C

STREAM HABITAT DEGRADATION

Physical characteristics of streams and streambanks, including the amount of bank vegetation, stability of bank soils, and stream depth and shape, strongly inﬂuence water quality and the ability of streams to support biological communities. The

physical condition of most stream

v i

habitat was about average compared R to conditions at other NAWQA Study Units.

c i

FISH COMMUNITY DEGRADATION e n

o C

The number of diseased, pollution- r

e tolerant, omnivorous, and non-native

v i R ﬁsh at several sites is higher than what would be expected in a healthy ﬁsh community. Fish communities in urban areas generally were in worse t u c i

e condition than those found in other n

n o

C NAWQA Study Units. There are no standards with which to evaluate the long-term ecological effects of these conditions.

U.S. Geological Survey Circular 1155 19

WATER-QUALITY CONDITIONS IN A NATIONAL CONTEXT Comparison of Ground-Water Quality in the Connecticut, Housatonic, and Thames River Basins with Nationwide NAWQA Findings

Water-quality characteristics were evaluated for ground-water studies in each NAWQA Study Unit. Ground-water resources were divided into two categories: (1) drinking-water aquifers, and (2) shallow ground water underlying agricultural or urban areas. Summary scores were computed for each characteristic for all aquifers and shallow ground-water areas that had adequate data. Scores for each aquifer and shallow ground-water area in the Connecticut, Housatonic, and Thames River Basins were compared with scores for all aquifers and shallow ground-water areas sampled in the 20 NAWQA Study Units during 1992Ð95. Results are summarized by percentiles; higher percentile values generally indicate poorer quality compared with other NAWQA ground-water studies. Water-quality conditions for each drinking-water aquifer also are compared to established drinking-water standards and criteria for protection of human health. (Methods used to compute rankings and evaluate standards and criteria are described by Gilliom and others, in press.)

PESTICIDES

Pesticide detection was common from EXPLANATION wells in agricultural areas, with detection in more than 80 percent of wells Fractured crystallineÐbedrock aquifer (FC) sampled. Concentrations were generally Agriculture (AG) low, with only two samples exceeding the Urban (UR) drinking water standards. Pesticides were Forest (FO) (FO) also commonly detected in urban wells, Ranking of ground-water quality relative but were detected much less frequently in (FC) to all NAWQA ground-water studies — (UR) forested areas and drinking-water Darker colored circles generally indicate (bedrock) wells. poorer quality. Bold outline of circle (AG) indicates one or more standards or criteria were exceeded.

Greater than the 75th percentile (among the highest 25 percent of NAWQA ground-water studies)

Between the median and the 75th percentile

Between the 25th percentile and the median

Less than the 25th percentile (among the lowest 25 percent of NAWQA ground-water studies)

NITRATE

(FO) Nitrate concentrations in shallow ground water under agricultural areas generally (FC) were greater than the national median (UR) concentration, and 15 percent of these wells exceeded the drinking-water (AG) standard for nitrate. In contrast, nitrate concentrations in other shallow ground water and bedrock wells generally were less than the national median for NAWQA sites.

20 Water Quality in the Connecticut, Housatonic, and Thames River Basins, 1992-95

WATER-QUALITY CONDITIONS IN A NATIONAL CONTEXT

CONCLUSIONS

In the Connecticut, Housatonic, and Thames River Basins, compared to other NAWQA Study Units: ¥ Pesticide detections were common, but concentrations generally were low. Samples from only 2 percent of the monitoring wells exceeded a pesticide MCL, and only in agricultural areas. ¥ VOCs were commonly detected in urban wells; samples from 10 percent of the wells in urban areas exceeded a VOC MCL. (FC) (UR) ¥ Nitrate concentrations in ground water under agricultural areas are 30 times higher than background concentrations; (AG) samples from 15 percent of these wells exceeded the nitrate MCL. ¥ Radon activities are high; activities in ground water from almost all bedrock wells exceeded the previously proposed limit.

VOLATILE ORGANIC COMPOUNDS Volatile organic compounds were frequently detected in study area wells, with more than 70 percent of urban wells sampled containing VOCs, placing them among the top 25 percent of all NAWQA ground-water samples. VOCs also were frequently detected in bedrock wells used for drinking water; however, VOCs were not frequently detected in wells in agricultural areas.

RADON Radon, a decay product of uranium, occurs naturally in soils. Radon levels in the drinking-water wells completed in bedrock were among the highest observed nationally. Almost all of these wells (97 percent) exceeded the previously proposed limit for radon. (FC)

U.S. Geological Survey Circular 1155 21

STUDY DESIGN AND DATA COLLECTION

Data collection efforts were designed to assess the quality of both surface and ground waters across the Study Unit for both regional and national needs (Gilliom and others, 1995). This design included three components, stream chemistry, stream ecology, and ground-water chemistry.

EXPLANATION STREAM-CHEMISTRY SAMPLING SITES Basic Intensive Synoptic Streambed sediment

STREAM CHEMISTRY

e Sampling sites were selected to assess the occurrence and distribution of dissolved constituents

v i

R in streamwater. Data from basic fixed sites were used to evaluate the effect of upstream land use on stream chemistry. Data from the intensive fixed site, which was sampled more frequently, was used to evaluate the seasonal variation of stream chemistry at an urban site. Synoptic surveys were conducted during two summers to evaluate the distribution of pesticides throughout the Study Unit. Samples were collected to assess the distribution of trace elements and organic compounds in bed sediments across the Study Unit.

c i

n STREAM ECOLOGY o

C Intensive ecological assessments were conducted at basic fixed sites across the Study Unit for use in measuring the impact water quality has had on aquatic EXPLANATION communities. These assessments included STREAM ECOLOGY SITES

the collection of fish, macroinvertebrate, Intensive Fish tissue and algae samples for indentification, along with habitat characterization at each site. Fish tissue samples were collected at

selected sites across the Study Unit for trace element and organic compound analysis.

EXPLANATION GROUND-WATER CHEMISTRY Study Unit survey wells Land use study wells

Stratified-drift deposits

Undifferentiated crystalline

r bedrock

i R GROUND-WATER CHEMISTRY

Ground-water samples were collected at two types of sites across the Study Unit, shallow wells in glacial stratified drift, and deeper wells in crystalline bedrock. Samples from shallow wells in stratified drift were collected to

t characterize the effects of land use on ground- u

c i

e water quality, whereas samples from the deeper n

o C bedrock wells were collected to characterize water-quality from water-supply wells in this Study Unit survey.

22 Water Quality in the Connecticut, Housatonic, and Thames River Basins, 1992-95

STUDY DESIGN AND DATA COLLECTION

Summary of Data Collection in the Connecticut, Housatonic, and Thames River Basins, 1992-95

Frequency Brief description and Number during Study component Objectives water-quality measures of sites 1992-95 Stream Chemistry Bottom-sediment survey Determine the presence of potentially Sample depositional zones of streams for trace 43 1 toxic compounds within the bed elements and hydrophobic organic compounds. (1992-94) sediments of streams. Water chemistry -- Describe concentrations and loads of Sample at or near sites where streamflow is 12 ~15 per year, Basic fixed sites chemicals, suspended sediment, and measured periodically for major ions, organic 3 years, nutrients at selected sites basin wide. carbon, suspended sediment, and nutrients. (1993-95) Water chemistry -- Determine concentration and timing of Sample one urban station where pesticides are 1 ~40 per year, Intensive fixed sites urban-related pesticides that run off to sampled at least monthly during winter, weekly in 2 years, streams. other seasons, and during selected runoff events. (1993-94) Water chemistry -- Describe the short-term presence and Sample streams during high flow and low flow 56 1 Synoptic studies distribution of contamination over conditions for pesticides and (or) nutrients, (1994-95) broad areas and determine how well suspended sediment, organic carbon, and the water chemistry stations represent streamflow. the Study Unit surface water. Stream Ecology Contaminants in fish Determine the presence of Collect specific fish species in the study area, 32 1 tissues contaminants that can accumulate in taking composites of whole fishes for organic (1992-94) fish tissues. compounds and fish livers for trace elements. Intensive ecological Assess in detail biological Sample and quantify fish, macroinvertebrates, and 10 1 per year, assessments communities and habitat in streams algae at or near a stream-chemistry station; 3 years, representing primary ecological describe stream habitat for these organisms; (1993-95) regions. replicate sampling for three consecutive years. Ground-Water Chemistry Study Unit survey Describe the overall water quality in Sample wells within crystalline bedrock across the 30 1 crystalline bedrock aquifers used for Study Unit for major ions, nutrients, volatile (1995) water supply. organic compounds, pesticides, and radionuclides. Land-use effects survey Determine the effects of specific land For surficial aquifers lying beneath major land 120 1 use on the quality of shallow ground uses, sample wells completed near water table for (1992-95) water in unconsolidated surficial major ions, nutrients, pesticides, volatile organic aquifers. compounds, and radionuclides. Variation along a Describe land-use effects in a surficial Sample clusters of wells installed along an 14 4-7 ground-water aquifer along a ground-water flow approximate line of ground-water flow and at (1994-95) flow path path, from recharge areas beneath various depths within a surficial aquifer; analyze urban land to discharge to a stream. for major ions, nutrients, trace elements, volatile organic compounds, pesticides, nitrogen isotopes, and age-dating constituents. Ground-water/surface- Determine the effects of ground-water Sample shallow ground water adjacent to two 13 1 water interactions discharge on surface-water quality. streams, and stream water; analyze for major ions, (1994-95) nutrients, pesticides, and volatile organic compounds.

U.S. Geological Survey Circular 1155 23 SUMMARY OF COMPOUND DETECTIONS AND CONCENTRATIONS The following tables summarize data collected for NAWQA studies from 1992–1995 by showing results for the Connecticut, Housatonic, and Thames River Basins Study Unit compared to the NAWQA national range for each compound detected. The data were collected at a variety of places and times. In order to represent the wide concentration ranges observed among Study Units, logarithmic scales are used to emphasize the general magnitude of the concentrations (such as 10, 100, or 1000), rather than the precise number. The complete dataset used to construct these tables is available upon request. Concentrations of herbicides, insecticides, volatile organic compounds, and nutrients detected in ground and surface waters of the Connecticut, Housatonic, and Thames River Basins Study Unit. [mg/L, milligrams per liter; µg/L, micrograms per liter; pCi/L, picocuries per liter; %, percent; <, less than; - -, not measured; trade names may vary]

a EXPLANATION Freshwater-chronic criterion for the protection of aquatic life Drinking water standard or guidelinea Range of surface-water detections in all 20 Study Units Range of ground-water detections in all 20 Study Units Detection in the Connecticut, Housatonic, and Thames River Basins Study Unit

Herbicide Rate Concentration, in µg/L Herbicide Rate Concentration, in µg/L (Trade or common of (Trade or common of name) detec- 0.001 0.01 0.1 1 10 100 1,000 name) detec- 0.001 0.01 0.1 1 10 100 1,000 tion b tion b Alachlor (Lasso) 3% Propachlor (Ramrod, <1% 0% propachlore) 0% Atrazine (AAtrex, 34% Propanil (Stampede, <1% Gesaprim) 17% Surcopur) <1% Desethylatrazinec 6% Simazine (Aquazine, 13% 6% (Atrazine metabolite) 17% Princep, GEsatop) Benfluralin (Balan, 1% Tebuthiuron (Spike, 0% Benefin, Bonalan) <1% Perflan) 1% Bromacil (Hyvar X, 0% Terbacilc (Sinbar) 1% Urox B, Bromax) 1% 1% Cyanazine (Bladex, 2% Triallate (Far-Go) 0% Fortrol) 0% <1% 2,4-D (2,4-PA) 2% Trifluralin (Treflan, 1% 0% Trinin, Elancolan) <1% DCPA (Dacthal, <1% chlorthal-dimethyl) <1% Dichlorprop (2,4-DP, 1% Insecticide Rate Concentration, in µg/L 1% Seritox 50, Kildip) (Trade or common of EPTC (Eptam) <1% name) detec- 0.001 0.01 0.1 1 10 100 1,000 <1% tion b Ethalfluralin 0% Aldicarb sulfoxidec 0% (Sonalan, Sonalen) <1% (Aldicarb metabolite) 1% Metolachlor 17% Carbaryl c 19% (Dual, Pennant) 2% (Sevin, Savit) 2% Metribuzin 4% Carbofuranc 1% (Lexone, Sencor) <1% (Furadan, Curaterr) 1% Napropamide 1% Chlorpyrifos 1% (Devrinol) 1% (Dursban, Lorsban) 0% Pendimethalin 1% p,p’-DDE (p,p’-DDT <1% (Prowl, Stomp) 0% metabolite) <1% Prometon (Gesagram 48% Diazinon 21% prometone) 6% 0%

24 Water-Quality in the Connecticut, Housatonic, and Thames River Basins, 1992-95 SUMMARY OF COMPOUND DETECTIONS AND CONCENTRATIONS

Insecticide Rate Concentration, in µg/L Volatile organic Rate Concentration, in µg/L (Trade or common of compound of name) detec- 0.001 0.01 0.1 1 10 100 1,000 (Trade or common detec- 0.01 0.1 1 10 100 1,000 tion b name) tion b Dieldrin (Panoram <1% Trichloroethene -- D-31, Octalox) 2% (TCE) 13% Disulfotonc <1% cis-1,2- -- (Disyton) 0% Dichloroethene 8% gamma-HCH <1% n-Butylbenzene -- 0% (1-Phenylbutane) 1% Malathion (Maldison, 4% n-Propylbenzene -- Malathon, Cythion) 0% (Isocumene) 1% cis-Permethrinc <1% p-Isopropyltoluene -- (Ambush, Pounce) <1% (p-Cymene) 1% Propargite (Comite, 4% sec-Butylbenzene -- Omite, BPPS) <1% 1%

Volatile organic Rate Concentration, in µg/L compound of Volatile organic Rate Concentration, in µg/L (Trade or common detec- 0.01 0.1 1 10 100 1,000 compound of name) tion b (Trade or common detec- 0.01 0.1 1 10 100 1,000 10,000 100,000 1,1,1-Trichloroethane -- name) tion b 2% Methyl tert-butyl -- 1,1-Dichloroethane -- etherd (MTBE) 25% 3% Tetrachloroethene -- 1,2,4-Trimethylben- -- (Perchloroethene) 9% zene (Pseudocumene) 1% 1,2-Dibromoethane -- (EDB) 1% 1,3,5-Trimethylben- -- zene (Mesitylene) 1% Nutrient Rate Concentration, in mg/L of Benzene -- (Trade or common detec- 0.01 0.1 1 10 100 1,000 10,000 100,000 1% name) tion b Dichlorodiﬂuo- -- Dissolved ammonia 85% 4% romethane (CFC 12) 70% Dichloromethane -- Dissolved ammonia (Methylene chloride) 2% plus organic nitrogen 60% Dimethylbenzenes -- as nitrogen 9% (Xylenes (total)) 1% Dissolved phospho- 68% Ethylbenzene -- rus as phosphorus 36% (Phenylethane) 1% Dissolved nitrite plus 97% Isopropylbenzene -- nitrate 85% (Cumene) 1% Methylbenzene -- (Toluene) 3% Naphthalene -- 2% Other Rate Concentration, in pCi/L of Tetrachloromethane -- detec- 1 10 100 1,000 10,000 100,000 1% tion b total Trihalomethanes -- Radon 222 -- 29% 100%

U.S. Geological Survey Circular 1155 25 SUMMARY OF COMPOUND DETECTIONS AND CONCENTRATIONS Herbicides, insecticides, volatile organic compounds, and nutrients not detected in ground and surface waters of the Connecticut, Housatonic, and Thames River Basins Study Unit.

Herbicides Picloram (Grazon, Tordon) Volatile organic Bromomethane (Methyl Nutrients compounds bromide) 2,4,5-T Pronamide (Kerb, No non-detects Propyzamid) Chlorobenzene 2,4,5-TP (Silvex, Fenoprop) 1,1,1,2-Tetrachloroethane Propham (Tuberite) (1,1,1,2-TeCA) (Monochlorobenzene) 2,4-DB (Butyrac, Thiobencarb (Bolero, 1,1,2,2-Tetrachloroethane Chloroethane (Ethyl Butoxone, Embutox Plus, chloride) Embutone) Saturn, Benthiocarb, 1,1,2-Trichloro-1,2,2- Abolish) Chloroethene (Vinyl 2,6-Diethylaniline trifluoroethane (Freon 113, chloride) (Metabolite of Alachlor) Triclopyr (Garlon, CFC 113) Grandstand, Redeem, Chloromethane (Methyl Acetochlor (Harness Plus, 1,1,2-Trichloroethane Remedy) chloride) Surpass) (Vinyl trichloride) Acifluorfen (Blazer, Tackle 1,1-Dichloroethene Dibromomethane 2S) Insecticides (Vinylidene chloride) (Methylene dibromide) Bentazon (Basagran, 3-Hydroxycarbofuran 1,1-Dichloropropene Ethenylbenzene (Styrene) Bentazone, Bendioxide) (Carbofuran metabolite) 1,2,3-Trichlorobenzene Hexachlorobutadiene (1,2,3-TCB) Bromoxynil (Buctril, Aldicarb sulfone (Standak, Trichlorofluoromethane Brominal) aldoxycarb, aldicarb 1,2,3-Trichloropropane (CFC 11, Freon 11) metabolite) (Allyl trichloride) Butylate (Sutan +, Genate cis-1,3-Dichloropropene Plus, Butilate) Aldicarb (Temik, Ambush, 1,2,4-Trichlorobenzene ((Z)-1,3-Dichloropropene) Pounce) Chloramben (Amiben, 1,2-Dibromo-3- tert-Butylbenzene Amilon-WP, Vegiben) Azinphos-methyl (Guthion, chloropropane trans-1,2-Dichloroethene Clopyralid (Stinger, Gusathion M) (DBCP, Nemagon) ((E)-1,2-Dichlorothene) Lontrel, Reclaim, Ethoprop (Mocap, 1,2-Dichlorobenzene Transline) Ethoprophos) (o-Dichlorobenzene, trans-1,3-Dichloropropene ((E)-1,3-Dichloropropene) Dacthal mono-acid (Dacthal Fonofos (Dyfonate, Capfos, 1,2-DCB) metabolite) Cudgel, Tycap) 1,2-Dichloroethane Dicamba (Banvel, Dianat, Methiocarb (Slug-Geta, (Ethylene dichloride) Scotts Proturf) Grandslam, Mesurol) 1,2-Dichloropropane Dinoseb (Dinosebe) Methomyl (Lanox, (Propylene dichloride) Diuron (Crisuron, Karmex, Lannate, Acinate) 1,3-Dichlorobenzene Direx, Diurex) Methyl parathion (m-Dichlorobenzene) Fenuron (Fenulon, Fenidim) (Penncap-M, Folidol-M, 1,3-Dichloropropane Metacide, Bladan M) Fluometuron (Flo-Met, (Trimethylene dichloride) Cotoran, Cottonex, Oxamyl (Vydate L, Pratt) 1,4-Dichlorobenzene Meturon) Parathion (Roethyl-P, (p-Dichlorobenzene, Linuron (Lorox, Linex, Alkron, Panthion, Phoskil) 1,4-DCB) Sarclex, Linurex, Afalon) Phorate (Thimet, Granutox, 1-Chloro-2- MCPA (Rhomene, Rhonox, Geomet, Rampart) methylbenzene (o-Chlorotoluene) Chiptox) Propoxur (Baygon, MCPB (Thistrol) Blattanex, Unden, 1-Chloro-4- Proprotox) methylbenzene Molinate (Ordram) (p-Chlorotoluene) Terbufos (Contraven, Neburon (Neburea, Counter, Pilarfox) 2,2-Dichloropropane Neburyl, Noruben) alpha-HCH (alpha-BHC, Bromobenzene (Phenyl Norflurazon (Evital, alpha-lindane, alpha- bromide) Predict, Solicam, Zorial) hexachlorocyclohexane, Bromochloromethane Oryzalin (Surflan, Dirimal) alpha-benzene (Methylene Pebulate (Tillam, PEBC) hexachloride) chlorobromide)

26 Water-Quality in the Connecticut, Housatonic, and Thames River Basins, 1992-95 SUMMARY OF COMPOUND DETECTIONS AND CONCENTRATIONS

Concentrations of semivolatile organic compounds, organochlorine compounds, and trace elements detected in fish tissue and bed sediment of the Connecticut, Housatonic, and Thames River Basins Study Unit. [µg/g, micrograms per gram; µg/kg, micrograms per kilogram; %, percent; <, less than; - -, not measured; trade names may vary]

EXPLANATION Guideline for the protection of aquatic life e Range of detections in ﬁsh and clam tissue in all 20 Study Units Range of detections in bed sediment in all 20 Study Units Detection in bed sediment or ﬁsh tissue in the Connecticut, Housatonic, and Thames River

Semivolatile Rate of Concentration, in µg/kg Semivolatile Rate of Concentration, in µg/kg organic compound detec- organic compound detection b 0.11 10 100 1,000 10,000 100,000 tion b 0.11 10 100 1,000 10,000 100,000

1,2,4- -- 4-Chlorophenyl- -- Trichlorobenzene 2% phenylether 2% 1,2-Dichlorobenzene -- 9H-Carbazole -- 2% 79% 1,2- -- 9H-Fluorene -- Dimethylnaphthalene 14% 80% 1,3-Dichlorobenzene -- Acenaphthene -- 2% 73% 1,4-Dichlorobenzene -- Acenaphthylene -- 9% 89% 1,6- -- Acridine -- Dimethylnaphthalene 59% 45% 1-Methyl-9H-fluorene -- Anthracene -- 48% 89% 1- -- Anthraquinone -- Methylphenanthrene 81% 86% 1-Methylpyrene -- Azobenzene -- 81% 2% 2,2-Biquinoline -- Benz[ a ]anthracene -- 21% 94% 2,3,6- -- Benzo[ a ]pyrene -- Trimethylnaphthalene 55% 92% 2,6- -- Benzo[ b ] -- Dimethylnaphthalene 89% fluoranthene 96% 2-Ethylnaphthalene -- Benzo[ ghi ]perylene -- 23% 81% 2-Methylanthracene -- Benzo[ k ] -- 74% fluoranthene 96% 3,5-Dimethylphenol -- Butylbenzylphthalate -- 2% 66% 4,5-Methyle- -- Chrysene -- nephenanthrene 84% 98% 4-Chloro-3- -- Di- n -butylphthalate -- methylphenol 2% 88%

U.S. Geological Survey Circular 1155 27 SUMMARY OF COMPOUND DETECTIONS AND CONCENTRATIONS

Semivolatile Rate of Concentration, in µg/kg Organochlorine Rate Concentration, in µg/kg organic compound detec- of 0.11 10 100 1,000 10,000 100,000 compound tion b detec- (Trade name) 0.01 0.1 1 10 100 1,000 10,000 100,000 tion b Di- n -octylphthalate -- total-DDT 97% 31% 70% Dibenz[a,h ] -- Dieldrin (Panoram 38% anthracene 67% D-31, Octalox) 20% Dibenzothiophene -- Endosulfan I (alpha- -- 73% endosulfan, Thiodan) 7% Diethylphthalate -- Heptachlor epoxide 3% 32% 0% Dimethylphthalate -- Hexachlorobenzene 6% 18% -- Fluoranthene -- p,p’-Methoxychlor 0% 98% (Marlate) 2% Indeno[1,2,3- cd ] -- Mirex (Dechlorane) 0% pyrene 85% 5% Isoquinoline -- PCB, total 88% 20% 23% Naphthalene -- Pentachloroanisole 22% 59% 0% N-Nitrosodi- -- phenylamine 7% Phenanthrene -- 91% Phenanthridine -- Rate Concentration, in µg/g 26% Trace element of Phenol -- detec- 0.01 0.1 1 10 100 1,000 10,000 93% tion b Pyrene -- Arsenic 71% 98% 100% Quinoline -- Cadmium 93% 16% 100% bis-(2-Ethylhexyl) -- Chromium 43% phthalate 96% 98% p-Cresol -- Copper 100% 70% 100% Lead 36% 100% Organochlorine Rate Concentration, in µg/kg Mercury 80% compound of 96% detec- (Trade name) 0.01 0.1 1 10 100 1,000 10,000 100,000 Nickel 29% tion b 100% total-Chlordane 78% Selenium 100% 34% 98% p,p’-DDE 97% Zinc 100% 64% 100%

28 Water-Quality in the Connecticut, Housatonic, and Thames River Basins, 1992-95 SUMMARY OF COMPOUND DETECTIONS AND CONCENTRATIONS Semivolatile organic compounds, organochlorine compounds, and trace elements analyzed for but not detected in fish tissue and bed sediment of the Connecticut, Housatonic, and Thames River Basins Study Unit.

Semivolatile Organochlorine beta-HCH (beta-BHC, gamma- Trace elements organic compounds beta- hexachlorocyclohexane, compounds hexachlorocyclohexane gamma-benzene No non-detects Aldrin (HHDN, Octalene) alpha-benzene hexachloride, gamma- 2,4-Dinitrotoluene hexachloride) Chloroneb (chloronebe, hexachlorocyclohexane, 2,6-Dinitrotoluene Demosan, Soil Fungicide cis-Permethrin (Ambush, gamma-benzene) 1823) Astro, Pounce, Pramex, 2-Chloronaphthalene o,p’-Methoxychlor Pertox, Ambushfog, Kafil, DCPA (Dacthal, 2-Chlorophenol Perthrine, Picket, Picket G, chlorthal-dimethyl) trans-Permethrin (Ambush, Dragnet, Talcord, 4-Bromophenyl- Astro, Pounce, Pramex, Endrin (Endrine) Outflank, Stockade, phenylether Pertox, Eksmin, Coopex, Peregin, Heptachlor (Heptachlore, Ambushfog, Kafil, Benzo [c] cinnoline Stomoxin, Stomoxin P, Velsicol 104) Perthrine, Picket, Picket G, Qamlin, Corsair, Tornade) C8-Alkylphenol Dragnet, Talcord, Isodrin (Isodrine, delta-HCH (delta-BHC, Outflank, Stockade, Isophorone Compound 711) delta- Eksmin, Coopex, Peregin, N-Nitrosodi-n- Toxaphene (Camphechlor, hexachlorocyclohexane, Stomoxin, Stomoxin P, propylamine Hercules 3956) delta-benzene Qamlin, Corsair, Tornade) hexachloride) Nitrobenzene alpha-HCH (alpha-BHC, alpha-lindane, alpha- gamma-HCH (Lindane, Pentachloronitrobenzene hexachlorocyclohexane, gamma-BHC, bis-(2-Chloroethoxy) alpha-benzene Gammexane, Gexane, methane hexachloride) Soprocide,

a Selected water-quality standards and guidelines (Gilliom and others, in press). b Rates of detection are based on the number of analyses and detections in the Study Unit, not on national data. Rates of detection for herbicides and insecticides were computed by counting only those detections equal to or greater than 0.01µg/L in order to facilitate equal comparisons among compounds, which had widely varying detection limits. For herbicides and insecticides, a detection rate of “<1%” means that all detections are less than 0.01µg/L, or the detection rate rounds to less than one percent. For other compound groups, all detections were counted and minimum detection limits for most compounds were similar to the lower end of the national ranges shown. Method detection limits for all compounds in these tables are summarized in Gilliom and others (in press). c Detections of these compounds are reliable, but concentrations are determined with greater uncertainty than for the other compounds and are reported as estimated values (Zaugg and others, 1995). d The guideline for methyl tert-butyl ether is between 20 and 40 µg/L; if the tentative cancer Classification C is accepted, the lifetime health advisory will be 20 µg/L (Gilliom and others, in press). e Selected sediment-quality guidelines (Gilliom and others, in press).

U.S. Geological Survey Circular 1155 29

THIS REPORT WAS BASED ON THE FOLLOWING PUBLICATIONS

Breault, R.F., and Harris, S.L., 1997, Grady, S.J., 1997, Occurrence of U.S. Environmental Protection Geographical distribution and volatile organic compounds in Agency, 1996, Drinking water potential for adverse biological ground water in the Connecticut, regulations and health advisories: effects of selected trace elements Housatonic, and Thames River Office of Water, EPA 822-R-96- and organic compounds in Basins: U.S. Geological Survey 001, 16 p. streambed sediment in the Fact Sheet FS-029-97, 6 p. _____1997, The Long Island Sound Connecticut, Housatonic, and Grady, S.J., and Mullaney, J.R., 1998, Study-Proposal for phase III Thames River Basins, 1992-94: Natural and human factors actions for hypoxia management: U.S. Geological Survey Water- affecting shallow water quality in EPA 840-R-97-001, 25 p. Resources Investigations Report surficial aquifers in the Vermont Department of Environmental 97-4169, 24 p. Connecticut, Housatonic, and Conservation, 1996, Water quality Brill, A.B., 1994, Facts concerning Thames River Basins: U.S. assessment: Waterbury, Vt. environmental radon, Journal of Geological Survey Water- Zimmerman, M.J., Grady, S.J., Trench, Nuclear Medicine, v. 35, no. 2. Resources Investigations Report E.C.T., Flanagan, S.M., and Coles, J.F., 1996, Organochlorine 98-4042, 81 p. Nielsen, M.G., 1996, Water- compounds and trace elements in Massachusetts Department of quality assessment of the fish tissue and ancillary data for Environmental Protection, 1995, Connecticut, Housatonic, and the Connecticut, Housatonic, and Summary of water quality: Thames River Basins study unit: Thames River Basins, 1992-94: Boston, Mass., 97 p. Analysis of available information on nutrients, suspended U.S. Geological Survey Open- Mitchell, W.B., Guptill, S.C., sediments, and pesticides, 1972- File Report 96-358, 26 p. Anderson, K.E., Fegas, R.G., and 92: U.S. Geological Survey Connecticut Department of Hallam, C.A., 1977, GIRAS—A Water-Resources Investigations Environmental Protection, 1994, geographic information and Report 95-4203, 162 p. Water quality report: Hartford, analysis system for handling land Zaugg, S.D., Sandstorm, M.W., Smith, Conn., 97 p. use and land cover data: U.S. S.G., and Fehlberg, K.M., 1995, _____1996, Connecticut waterbodies Geological Survey Professional Methods of analysis by the U.S. not meeting water-quality Paper 1059, 16 p. standards in 1996: Hartford, Geological Survey National National Academy of Sciences and Water Quality Laboratory— Conn., 24 p. National Academy of Ecosystem Conservation Determination of pesticides in Engineering, 1973 [1974], Water- water by C-18 solid-phase Directorate—Evaluation and quality criteria, 1972: U.S. Interpretation Branch, 1995, extraction and capillary-column Environmental Protection gas chromatography/mass Interim sediment quality Agency, EPA R3-73-033, 594 p. guidelines: Ottawa, Ontario, Soil spectrometry with selected-ion New Hampshire Department of and sediment quality section, monitoring: U.S. Geological Environmental Services, 1996, Guidelines Division, 12 p. Survey Open-File Report 95-181, Water quality report: Concord, Gilliom, R.J., Alley, W.M., and Gurtz, 49 p. N.H. M.E., 1995, Design of the Zimmerman, M.J., 1997, Trends in National Water-Quality Trench, E.C.T., 1996, Trends in nitrogen and phosphorus Assessment Program— surface-water quality in concentrations in southern New Occurrence and distribution of Connecticut, 1969-88: U.S. England streams, 1974-92: U.S. water-quality conditions: U.S. Geological Survey Water- Geological Survey Fact Sheet Geological Survey Circular 1112, Resources Investigations Report FS-001-97, 4 p. 33 p. 96-4161, 176 p. Gilliom, R.J., Muller, D.K., and U.S. Environmental Protection Nowell, L.H., in press, Methods Agency, 1994,Water quality for comparing water-quality standards handbook (2nd ed.): conditions among National U.S. Environmental Protection Water-Quality Assessment Study Agency: EPA-823-B-94-005b, Units, 1992-1995: U.S. Appendix P, 3 p. Geological Survey Open-File Report 97-589.

30 Water Quality in the Connecticut, Housatonic, and Thames River Basins, 1992-95

GLOSSARY

The terms in this glossary were compiled from numerous sources. Some deﬁnitions have been modiﬁed and may not be the only valid ones for these terms.

Ammonia - A compound of nitrogen Chlordane - Octachloro-4,7- sanitary quality of water for body- and hydrogen (NH3) that is a methanotetrahydroindane. An contact recreation or for common by-product of animal organochlorine insecticide no consumption. Their presence waste. Ammonia readily converts longer registered for use in the indicates contamination by the to nitrate in soils and streams. U.S. Technical chlordane is a wastes of warm-blooded animals Aquatic-life criteria - Water-quality mixture in which the primary and the possible presence of guidelines for protection of components are cis- and trans- pathogenic (disease producing) aquatic life. Often refers to U.S. chlordane, cis- and trans- organisms. Environmental Protection Agency nonachlor, and heptachlor. Health advisory - Nonregulatory levels water-quality criteria for Concentration - The amount or mass of contaminants in drinking water protection of aquatic organisms. of a substance present in a given that may be used as guidance in See also Water-quality guidelines, volume or mass of sample. the absence of regulatory limits. Water-quality criteria, and Usually expressed in micrograms Advisories consist of estimates of Freshwater chronic criteria. per liter (water sample) or concentrations that would result in Aquifer - A water-bearing layer of soil, micrograms per kilogram no known or anticipated health sand, gravel, or rock that will yield (sediment or tissue sample). effects (for carcinogens, a usable quantities of water to a Detection limit - The concentration specified cancer risk) determined well. below which a particular for a child or for an adult for Atmospheric deposition - The transfer analytical method cannot various exposure periods. of substances from the air to the determine, with a high degree of Herbicide - A chemical or other agent surface of the Earth, either in wet certainty, a concentration. applied for the purpose of killing form (rain, fog, snow, dew, frost, DDT - Dichloro-diphenyl- undesirable plants. See also hail) or in dry form (gases, trichloroethane. An Pesticide. aerosols, particles). organochlorine insecticide no Indicator sites - Stream sampling Basic Fixed Sites - Sites on streams at longer registered for use in the sites located at outlets of drainage which streamflow is measured and United States. basins with relatively samples are collected for Dieldrin - An organochlorine homogeneous land use and measurement of analysis of insecticide no longer registered for physiographic conditions; most temperature, salinity, suspended use in the United States. Also a indicator-site basins have drainage sediment, major ions and metals, degradation product of the areas ranging from 20 to nutrients, and organic carbon to insecticide aldrin. 200 square miles. assess the broad-scale spatial and Drainage basin - The portion of the Insecticide - A substance or mixture of temporal character and transport surface of the Earth that substances intended to destroy or of inorganic constituents of contributes water to a stream repel insects. streamwater in relation to through overland run-off, Integrator or Mixed-use site - Stream hydrologic conditions and including tributaries and sampling site located at an outlet environmental settings. impoundments. of a drainage basin that contains Bed sediment - The material that Effluent - Outflow from a particular multiple environmental settings. temporarily is stationary in the source, such as a stream that Most integrator sites are on major bottom of a stream or other flows from a lake or liquid waste streams with relatively large watercourse. that flows from a factory or drainage areas. Benthic - Refers to plants or animals sewage-treatment plant. Intensive Fixed Sites - Basic Fixed that live on the bottom of lakes, Eutrophication - The process by Sites with increased sampling streams, or oceans. which water becomes enriched frequency during selected Breakdown product - A compound with plant nutrients, most seasonal periods and analysis of derived by chemical, biological, or commonly phosphorus and dissolved pesticides for 1 year. physical action upon a pesticide. nitrogen. Most NAWQA Study Units have The breakdown is a natural Fecal bacteria - Microscopic single- one to two integrator Intensive process which may result in either celled organisms (primarily fecal Fixed Sites and one to four a more toxic or a less toxic coliforms and fecal streptococci) indicator Intensive Fixed Sites. compound and either a more found in the wastes of warm- Maximum contaminant level persistent or less persistent blooded animals. Their presence (MCL) - Maximum permissible compound. in water is used to assess the level of a contaminant in water

U.S. Geological Survey Circular 1155 31

GLOSSARY

that is delivered to any user of a Organochlorine compound - A generally encompass more than public water system. MCLs are synthetic organic compound 4,000 square miles of land area. enforceable standards established containing chlorine. As generally Synoptic sites - Sites sampled during a by the U.S. Environmental used, the term refers to short-term investigation of Protection Agency. compounds containing mostly or specific water-quality conditions exclusively carbon, hydrogen, during selected seasonal or Mean - The arithmetic average of a set and chlorine. Examples include hydrologic conditions to provide of observations, unless otherwise organochlorine insecticides, improved spatial resolution for specified. polychlorinated biphenyls, and critical water-quality conditions. Median - The middle or central value some solvents containing Volatile organic compounds in a distribution of data ranked in chlorine. (VOCs) - Organic chemicals that order of magnitude. The median Picocurie (pCi) - One trillionth (10-12) have a high vapor pressure is also known as the 50th of the amount of radioactivity relative to their water solubility. percentile. represented by a curie (Ci). VOCs include components of Micrograms per liter (µg/L) - A unit A curie is the amount of gasoline, fuel oils, and lubricants, expressing the concentration of radioactivity that yields 3.7 x 1010 as well as organic solvents, constituents in solution as weight radioactive disintegrations per fumigants, some inert ingredients (micrograms) of solute per unit second. in pesticides, and some by- volume (liter) of water; equivalent Polychlorinated biphenyls (PCBs) - products of chlorine disinfection. to one part per billion in most A mixture of chlorinated Water-quality criteria - Specific stream water and ground water. derivatives of biphenyl, marketed levels or concentrations of One thousand micrograms per under the trade name Aroclor chemical constituents of organic liter equals 1 mg/L. with a number designating the compounds in water, which, if Milligrams per liter (mg/L) - A unit chlorine content (such as Aroclor exceeded, are considered to expressing the concentration of 1260). PCBs were used in render a body of water unsuitable chemical constituents in solution transformers and capacitors for for its designated use. Commonly as weight (milligrams) of solute insulating purposes and in gas refers to water-quality criteria per unit volume (liter) of water; pipeline systems as a lubricant. established by the U.S. equivalent to one part per million Further sale for new use was Environmental Protection in most stream water and ground banned by law in 1979. Agency. Water-quality criteria are water. One thousand micrograms Polycyclic aromatic hydrocarbon based on specific levels of per liter equals 1 mg/L. (PAH) - A class of organic pollutants that would make the compounds with a fused-ring water harmful if used for National Academy of aromatic structure. PAHs result drinking, swimming, farming, Sciences/National Academy of from incomplete combustion of fish production, or industrial Engineering (NAS/NAE) organic carbon (including wood), processes. recommended maximum municipal solid waste, and fossil Water year - The continuous 12- concentration in water - fuels, as well as from natural or month period, October 1 through Numerical guidelines anthropogenic introduction of September 30, in U.S. Geological recommended by two joint uncombusted coal and oil. PAHs Survey reports dealing with the NAS/NAE committees for the include benzo(a)pyrene, surface-water supply. The water protection of freshwater and fluoranthene, and pyrene. year is designated by the calendar marine aquatic life, respectively. Semivolatile organic compound year in which it ends and which These guidelines were based on (SVOC) - Operationally defined includes 9 of the 12 months. available aquatic toxicity studies, as a group of synthetic organic Thus, the year ending September and were considered preliminary compounds that are solvent- 30, 1980, is referred to as the even at the time (1972). The extractable and can be determined "1980" water year. guidelines used in the NAWQA by gas chromatography/mass summary reports are for spectrometry. SVOCs include freshwater. phenols, phthalates, and Nitrate - An ion consisting of nitrogen Polycyclic aromatic hydrocarbons - and oxygen (NO3 ). Nitrate is a (PAHs). plant nutrient and is very mobile Study Unit - A major hydrologic in soils. system of the United States in Nutrient - An element or compound which NAWQA studies are essential for animal and plant focused. Study Units are growth. Common nutrients in geographically defined by a fertilizer include nitrogen, combination of ground- and phosphorus, and potassium. surface-water features and

32 Water Quality in the Connecticut, Housatonic, and Thames River Basins, 1992-95