The U.S. Geological Survey (USGS), 

established by Congress in the Organic 

Act on March 3, 1879, provides geologic, 

topographic, hydrologic, and biologic 

information to the Nation. The USGS 

works in partnership with State and local 

municipalities and other Federal agencies 

to produce and disseminate information 

that is relevant to the economic and environmental well-being of the citizens of 

Rhode Island.

Water Supply and Use

Water supplies in Rhode Island are a 

limited resource. Consulting firms and 

State and town officials need basic hydrologic data to plan and regulate waterresources development. The USGS, in 

cooperation with several State and Federal 

agencies, collects data from an extensive 

network of surface- and ground-watermonitoring sites. The data from these networks are needed to assess current water 

availability and predict water availability 

during drought.

The Scituate Reservoir system (figs. 1 

and 2) is the principal source of drinking 

water for Rhode Island. The USGS, the 

Providence Water Supply Board (PWSB), 

and the Rhode Island Department of Environmental Management (DEM) are participating in a program to assess the flow and 

quality of water in the streams that contribute to the reservoir.

Low-flow estimates provide the basis 

for formulating surface- and groundwater basin yield estimates. Information 

about changes in the water-quality conditions of streams that contribute to the reservoir and which subbasins in the 

watershed are most affected helps the 

PWSB to improve watershed management 

practices and to protect water quality at 

the water-purification plant intake rather 

than increase treatment of water.

Because Block Island derives its water 

supply from ponds and wells on the 

island, protection of the ground-water 

resources is of paramount concern. The 

USGS recently studied the ground water 

on the island. Results of the study 

assisted water-resources managers to 

determine how much water was available 

and how it could best be developed.

In the late 1960’s, the Rhode Island 

Water Resources Board (WRB) determined that ground water was the only viable source of additional water for public 

supply in southern Rhode Island. The 

USGS, through its 30-year cooperative 

program with the WRB, has studied 

ground water in several basins of Rhode 

Island, including each of five study areas 

in the Pawcatuck River Basin in southern 

Rhode Island (fig. 2). These studies identified areas in which hydrogeologic conditions are favorable for development of 

ground-water supplies and evaluated the 

effects of ground-water development on 

water levels and streamflow. The USGS 

and the WRB are conducting a groundwater investigation of part of the South 

Branch of the Pawtuxet River Basin, with 

an emphasis on the 8,600-acre Big River 

Management Area. The Management Area 

is maintained as open space. The WRB 

would like to develop ground-water 

resources in the Management Area by 

identifying sites that can produce 1 million 

gallons per day or more to individual wells 

as part of an interim water-supply 

augmentation scheme.

The USGS has developed a water-use 

data base that describes where, how, and 

what quantities of water in the State are 

being used. These data were used in a case 

Index of Subjects

Water Supply and Use

Evaluating Human Effects on Water Quality

Radon

Vulnerability of Ground-Water Supplies

Topographic Mapping

Cooperative Programs

Mineral Production Information

Marine and Coastal Research

Figure 1. View of the Scituate Reservoir, Rhode Island.

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

U.S. Geological Survey

Programs in Rhode Island

Earth Science in the Public Service
42 ̊00'

41 ̊30'

71 ̊15'

71 ̊45'

Cumberland

North Kingston

Richmond

MASSACHUSETTS

MASSACHUSETTS

CONNECTICUT

BLOCK

ISLAND

Scituate Reservoir

B L O C K I S L A N D S O U N D

Beaver River

study area

Upper Wood

River study

 area

UsquepaugQueen River

study

area Chipuxet River 

study

area

Lower Wood

River 

 study area 

BLACKSTONE

PAWTUXET

QUINEBAUG

PAWCATUCK

ANNAQUATUCKET

SAUGATUCKET PETTAQUAMSCUTT

MASKERCHUGG

TAUNTON

WOONASQUATUCKET

TENMILE

HUNT

MOSHASSUCK

0 10 MILES

0 10 KILOMETERS

EXPLANATION

DRAINAGE-BASIN 

BOUNDARY

DRAINAGE-SUBBASIN 

BOUNDARY

LOW-LEVEL RADIOACTIVE MATERIAL 

STUDY SITE

study in Cumberland that demonstrated 

the integration of water-use data collected 

by State agencies, water suppliers, and 

wastewater-treatment facilities.

The water demands of many New 

England communities are reaching operational capacities of current supplies. Furthermore, new sources of water are 

increasingly difficult to develop because 

of contamination of water supplies and 

environmental-protection goals. To augment existing supplies, it is necessary to 

understand the interaction between water 

availability and water use, particularly at 

the regional or basin scale. The USGS, in 

cooperation with the DEM and North 

Kingstown, is evaluating water-resource 

planning alternatives for the Hunt, 

Annaquatucket, and Pettaquamscutt 

River Basins. The study is identifying 

ground-water-development strategies that 

meet public-supply needs and that minimize the effects of water development on 

streamflow. 

Evaluating Human Effects on 

Water Quality

Development throughout Rhode Island 

has affected water quality. The USGS 

water-quality-monitoring program provides data that can be used to determine 

the quality of surface water and the longand short-term trends in water quality; 

to monitor compliance with Federal and 

State water-quality standards; and to demonstrate the effects of land-use practices 

on water quality (fig. 3). The water-quality 

data are needed by the DEM for complying with Federal monitoring requirements. 

The USGS state-of-the-art sampling protocols, equipment, and laboratory facilities 

assure that the State will receive accurate 

and complete information.

As part of a nationwide research program on ground-water contamination by 

toxic substances, the USGS conducted an 

intensive study in an area of southern 

Rhode Island that was contaminated by 

liquid wastes from an enriched-uranium 

cold-scrap recovery plant. Hydrologists 

sampled the local ground water and 

mapped an underground plume of lowlevel radioactive contamination (fig. 4). 

Data collected from 1981 to 1984 indicate 

that the plume discharged to the Pawcatuck River. Water-quality samples were 

again collected in 1990 and 1993 to determine how the plume had moved during 

the intervening years. Computer simulations were used to estimate how long it 

would take for the contamination to be 

flushed naturally from the ground-water 

system and the estimates ranged from 8

to 18 years.

Development of rural areas creates the 

need to install new septic systems. The 

ability to predict the highest elevation 

that the water table will attain is needed 

Figure 2. State of Rhode Island watersheds and towns and areas studied by USGS.

Figure 3. Water-quality data-collection sites.
for ensuring that septic-system leach 

fields will not be flooded. Ground-water 

levels typically are highest in the spring 

and, until recently, almost all proposed 

septic-system sites in rural areas of the 

State were required to be tested in the 

spring. The USGS, in cooperation with 

the DEM, has developed a method by 

which a single water-level measurement 

made at any time during the year at a site 

of interest can be used to estimate the 

long-term high water level at that site. 

The same method can be used to predict 

the low water level, or the median water 

level, which is needed for studies of longterm ground-water availability.

Radon

Faculty and students from the Department of Geology, University of Rhode 

Island and the State Geologist of Rhode 

Island are working cooperatively with the 

USGS to develop a geographic information system (GIS) analysis of surface 

radioactivity, geology, and the occurrence 

of indoor radon. This cooperative project 

is part of a larger effort involving the 

USGS, the U.S. Department of Energy, 

and the U.S. Environmental Protection 

Agency (USEPA) to develop a method to 

determine the locations of areas where 

homes may have radon concentrations 

that exceed the occupational radiation 

limit, which is equivalent to 20 picocuries 

per liter of radon. Measurements of 

soil/gas radon and gamma-ray activity 

were made, and samples of soil and rock 

were collected. The data have been 

entered into the GIS along with surficial 

geology information and data from a new 

bedrock geology map of Rhode Island 

published by the Office of the Rhode 

Island State Geologist.

Vulnerability of Ground-Water 

Supplies

The USGS, in cooperation with the 

Rhode Island Department of Health 

(RIDOH), is conducting a study to classify specific supply systems by their vulnerability to specific classes of natural 

and manmade constituents including 

organic compounds, pesticides, and trace 

elements. This cooperative project is part 

of a larger effort involving the USGS and 

the USEPA. Under authority of the Safe 

Drinking Water Act of 1974, the USEPA 

promulgates national drinking-water regulations. Recently, the USEPA developed a draft proposal for reforming the 

chemical monitoring requirements for 

community water systems (CWS) and 

nontransient, noncommunity water systems (NTNCWS). The results of the 

investigations enable RIDOH to define 

the factors that affect the relative vulnerability of each of the State’s CWS and 

NTNCWS to differing land uses and 

chemical constituents. 

Topographic Mapping

Among the most popular and versatile 

products of USGS are its 1:24,000-scale 

topographic maps (1 inch on the map represents 2,000 feet on the ground). These 

maps depict natural and cultural features 

of the landscape, such as lakes and 

streams, highways and railroads, boundaries, and geographic names. Contour 

lines depict the elevation and shape of 

terrain. Rhode Island is covered by 37 

maps that are used for civil engineering, 

land-use planning, natural-resource monitoring, and other technical applications. 

These maps also are favorites with the 

general public for outdoor uses, including 

hiking, camping, exploring, and backcountry fishing expeditions.

Cooperative Programs

The USGS works in cooperation with 

Federal, State, and local agencies to 

ensure that data collection and scientific 

investigations are relevant to public needs. 

Some current and recent cooperators in 

the cost-sharing program are: the Rhode 

Island Department of Environmental 

Management, the Rhode Island Water 

Resources Board, the Rhode Island 

Department of Health; the Providence 

Water Supply Board; and the Towns of 

North Kingstown and New Shoreham 

(Block Island). The USGS provides support to the Rhode Island Water Resources 

Center, which conducts a program of 

research, education, and information and 

technology transfer.

Mineral Production 

Information

Rhode Island ranked 48th among the 50 

States in nonfuel mineral production in 

1995 with an estimated value of $30 

million. Construction sand, gravel, and 

crushed stone accounted for most of the 

nonfuel mineral production in the State. 

Crushed stone was mostly produced for 

various construction purposes, although 

some agricultural limestone was produced.

Marine and Coastal Research

The USGS conducts a wide range of 

geological and geophysical research and 

mapping investigations of continental 

margins through its Woods Hole Field 

Center in Massachusetts. From this Field 

Center, scientists carry out investigations 

primarily along the U.S. Atlantic coast 

and in the Gulf of Mexico, the Caribbean 

Sea, the Great Lakes, and the polar 

regions. These studies address critical 

issues in environmental quality and preservation, geologic hazards and public 

safety, natural resources, global environmental change, and information and technology. The long-range goal is to develop 

a predictive capability to guide and 

assess the consequences of the use of the 

continental margins.

x

x x

x x

x

x

x

x

x

x

Pawcatuck

River

x

8

50

8

SEPTEMBER AND OCTOBER 1982

Nuclear processing site

50

250

x x

x x

x x

x

x

x

x

x

x

1000 FEET

0 150 300 METERS

0 500

JANUARY 1984

River

Pawcatuck

Fence

Line of equal strontium-90 

concentration.Interval, in 

picocuries per liter, is variable

x

EXPLANATION

50

8

8

8

Figure 4. Strontium-90 concentrations in 

ground water. Location shown in figure 2.
For More

Information Storms cause damage to coastal environments; however, the effect of storms 

on the adjacent inner Continental Shelf 

is virtually unknown. The USGS, in 

collaboration with researchers from 

Columbia University, has been monitoring the effects of hurricanes and large 

winter storms on this inner shelf environment in Block Island Sound. A large 

area was imaged in 1991 using sidescan 

sonar techniques, and it then was surveyed again in 1994 after Hurricane 

Bob and two major nor'easters. 

Although some changes caused by these 

storms can be observed, the most dramatic changes are due to the intense 

fishing in this area. Linear and sinuous 

furrows caused by trawl doors and 

dredges have extensively reworked 

large parts of the sea floor (fig. 5). 

A better understanding of the extent 

of this reworking of the sea floor will 

contribute to better management of the 

fisheries in Block Island Sound.

USGS state representative

275 Promenade St., Suite 150

Providence, R.I.

(401) 331-9050

Fax: (401) 331-9062

Email: oc_ri.usgs.gov

Additional earth science

information can be found by

accessing the USGS Home Page

on the World Wide Web at

http://www.usgs.gov/

For more information on

all USGS reports and products

(including maps, images,

and computerized data), call

1-800-USA-MAPS

The USGS provides maps,

reports, and information to help

others meet their needs to manage,

 develop, and protect America’s water,

energy, mineral, biological, and land

resources. We help find the natural

resources needed to build tomorrow,

and supply the scientific understanding needed to help minimize or mitigate the effects of natural hazards

and environmental damage caused

by natural and human activities. The

results of our efforts touch the daily

 life of almost every American.

U.S. Geological Survey

Fact Sheet FS-039-96

Figure 5. Detailed comparison from the 1991 and 1994 surveys of the seabed in an area of 

Block Island Sound. Note that the same boulders appear in the upper left corner of the image and 

that trawls marks in the 1994 image are absent in the 1991 image. Images represent an area of 

300 by 500 meters