Report Released on Potential Ground Water Yields of Bedrock Aquifers in New Hampshire

Results of a study of potential ground-water yields from bedrock aquifers in New Hampshire are described in a newly released report by the U.S. Geological Survey (USGS), in cooperation with the State of New Hampshire, Department of Environmental Services (NHDES). The bedrock aquifer in New Hampshire is composed of fractured rock that can store water and act as passageways for ground-water movement. Wells drilled into fractures obtain water for household, commercial, and industrial use. Currently, more than 45 percent of ground-water withdrawals in New Hampshire are from these aquifers. Finding high-yielding sites within these aquifers, however, can be difficult and costly.

The 8-year study resulted in the completion of a statistical model of well-yield probabilities that can provide information for use by communities, industry, professional consultants, and others to increase success rates of locating high-yield water supplies in bedrock aquifers."The USGS used the water yields of 20,308 New Hampshire bedrock wells as the basis for the study to produce statewide data on well-yield probabilities," says Richard Moore, USGS Hydrologist and Project Chief. Results of the statistical model indicate that well yield generally is lower on steep hill slopes and hill tops and at greater distances from surface-water bodies. Well yields tend to be greater in valleys and near some types of natural linear patterns on the Earth's surface that may indicate underlying fractures. "Well yields also appeared to be related to rock types," said Moore. For example, statistically higher yields in wells were discovered in the metamorphic rocks of the Frontenac Formation in northern New Hampshire and of the Rye Formation in coastal New Hampshire.

To better identify areas with the greatest probability of high well yields, scientists conducted field studies for two areas centered on Bedford and Windham, N.H., and collected more detailed information about the geology, including the location of fractures in the bedrock. The results demonstrated that by adding more detailed information to the model, additional potentially high-yield areas could be identified.

This newly released report is titled, "Factors Related to Well Yield in the Fractured-Bedrock Aquifer of New Hampshire," by Richard Bridge Moore and others, Professional Paper 1660, and is available for inspection at the USGS office in Pembroke, NH by calling (603) 226-7837 or can be ordered at cost by calling 1-888-ASK-USGS (1-888-275-8747).

As the nation's largest water, earth and biological sciences and civilian mapping agency, the USGS works in cooperation with more than 2,000 organizations across the country to provide reliable, impartial, scientific information to resource managers, planners, and other customers. This information is gathered in every state by USGS scientists to minimize the loss of life and property from natural disasters, contribute to sound conservation, economic and physical development of the nation's natural resources, and enhance the quality of life by monitoring water, biological, energy and mineral resources.

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Editors Note:

News Release Address:

New Hampshire/Vermont District
U.S. Department of the Interior
361 Commerce Way
Pembroke, NH 03275

Email: dhfoster@usgs.gov

Contacts: Phone: Fax: (603) 226-7894

General: Debra Foster (603) 226-7837

Technical: Tom Mack (603) 226-7805 tjmack@usgs.gov

Information about USGS Water-Resources Programs in New Hampshire and Vermont may be found on the web page http://nh.water.usgs.gov

In-depth information about USGS programs may be found on the USGS web page:

http://www.usgs.gov or http://water.usgs.gov .