U.S. Geological Survey
U.S. Department of the Interior
News Release
Date: May 25, 2006
Contact: Joseph Ayotte 603-226-7837 jayotte@xxxxxxxx
Debra Foster 603-226-7810 dhfoster@xxxxxxxx
__________________________________________________________________________
USGS Report Shows Where Arsenic is Most Likely in New England’s Ground Water
Note to Editors: The complete findings, released in the journal Environmental Science and Technology, are available at http://nh.water.usgs.gov
Many private groundwater wells in New Hampshire and Maine may have arsenic at concentrations close to or above Federal safety standards for public water supplies. A recently released study by the U.S. Geological Survey (USGS) shows the likely locations of elevated arsenic. Bedrock aquifer wells -- often known as rock, deep, or artesian wells -- are the most common type of well installed for homes in the region and it is the bedrock aquifer that is the primary source of arsenic in the locations where it is elevated, according to the findings.
“Our study shows where the highest probability of having arsenic in wells occurs,” USGS hydrologist Joseph Ayotte said. “We knew from previous studies that arsenic is a regional problem in New England. The information is intended to assist planners and health officials. It is also intended to help owners in deciding whether to test their well.”
The study, published in the journal Environmental Science and Technology, identifies factors that may contribute to high arsenic in wells, and confirms findings from previous studies.
Private wells supply drinking water for over 40 percent of the population of northern New England (20 percent of all of New England) and are not regulated by state and Federal agencies. Officials recommend that all private well users test their wells for arsenic.
The collaborative study between the USGS and the National Cancer Institute, part of the National Institutes of Health, concluded that geology was the most significant factor related to arsenic in wells. Other factors include the chemistry of the ground water and characteristics of local aquifers.
The current Federal standard for arsenic in public water supplies is 10 micrograms per liter. In New England, 12 percent of the area studied has a greater than 50 percent chance of having wells with arsenic concentrations above 5 micrograms per liter,. Nearly one-quarter of the combined area studied in Maine and New Hampshire has a greater than 50 percent chance of having wells with arsenic at or above 5 micrograms per liter.
"Arsenic in groundwater used for private or a public water supply is a significant public health concern," said Robert W. Varney, regional administrator of the U.S. Environmental Protection Agency's (EPA) New England office. "To protect families, EPA recommends that private well owners routinely test their drinking water for arsenic. As of January 2006, public water suppliers are required to meet a new drinking water standard of 10 micrograms per liter."
Arsenic is probably better known as causing acute illness at higher doses. But health effects from long-term exposure at low levels, such as those found in this study, are unclear.
According to Ayotte, this new study is consistent with other, recent studies that have suggested that arsenic is predominantly naturally occurring and related to the geology of the area. “Although human sources may contribute arsenic to ground water, our results suggest that arsenic used as an agricultural pesticide over the past century is not a major source of arsenic in ground water today,” Ayotte said.
The complete findings, released in the journal Environmental Science and Technology, are available at http://nh.water.usgs.gov
Health Information Summaries on arsenic can be found on State and Federal web sites at:
New Hampshire:
http://www.dhhs.state.nh.us/DHHS/HLTHRISKASSESS/LIBRARY/Fact+Sheet/contaminants.htm.
Maine:
http://www.maine.gov/dhhs/eohp/wells/asbrochure.shtml
Vermont:
http://healthvermont.gov/enviro/water/arsenic.pdf
Massachusetts:
http://www.mass.gov/dep/water/drinking/arswell.htm
U.S. Environmental Protection Agency:
http://www.epa.gov/safewater/arsenic/basicinformation.html
Agency of Toxic Substances and Disease Registry:
http://www.atsdr.cdc.gov/arsenic/index.html
The USGS serves the nation by providing reliable scientific information to describe and understand the Earth; minimize loss of life and property from natural disasters; manage water, biological, energy, and mineral resources; and enhance and protect our quality of life.
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to www.usgs.gov/public/list_server.html
The USGS serves the nation by providing reliable
scientific information to describe and understand the Earth; minimize loss
of life and property from natural disasters; manage water, biological,
energy, and mineral resources; and enhance and protect our quality of life.
To receive USGS news releases go to www.usgs.gov/public/list_server.html.
***www.usgs.gov***
Diane Noserale
Media Relations, Eastern Region
U.S. Geological Survey
150 National Center
Reston, VA 20192
phone: 703-648-4333
fax: 703-648-4588
