LOW CONCENTRATIONS OF ARSENIC FOUND IN GROUND WATER IN MANY SOUTHEAST MICHIGAN COUNTIES

Low concentrations of naturally-occurring arsenic are present in ground water in 9 southeast Michigan counties.  These results come from a recently completed cooperative effort by U.S. Geological Survey (USGS), Michigan Department of Environmental Quality (MDEQ), and the Health Departments of Genesee, Huron, Lapeer, Livingston, Oakland, Sanilac, Shiawassee, Tuscola and Washtenaw Counties.  Median arsenic concentrations in ground water in the 9 counties ranged from 2.9 micrograms per liter in Washtenaw County, to 16.6 micrograms per liter in Genesee County. 

The study examined records of arsenic concentration in 3,022 domestic and public wells in the 9-county area.  All of the counties studied had some wells with arsenic concentrations above the Environmental Protection Agency’s new standard of 0.01 milligrams (10 micrograms) per liter, set to take effect Jan 23, 2006; all except Livingston, Shiawassee, and Washtenaw had some arsenic concentrations exceeding the old standard of 50 micrograms per liter.  Arsenic concentrations above 50 micrograms per liter were found in water from wells tapping the Marshall Sandstone, Saginaw Formation, Michigan Formation, and Coldwater Shale, and above 40 micrograms per liter in overlying glacial materials.  Long-term consumption of arsenic has been linked to skin, bladder, lung, and prostate cancer, as well as other non-cancerous health effects.  However, the concentrations of arsenic that result in these long-term effects have not been clearly established.

Results of the study are provided in a set of eight fact sheets -- one for each county -- titled “Arsenic in Ground Water in XXX County, Michigan” by Sheridan K. Haack and Cynthia M. Rachol.   Oakland County results were previously released in a report titled “Arsenic, Nitrate, and Chloride in Ground Water, Oakland County, Michigan, by Stephen Aichele, Richard Hill-Rowley, and Matt Malone. The fact sheets, with maps showing arsenic distribution in each of the counties, and other information about arsenic in drinking water are also available at USGS Michigan District’s web site at http://mi.water.usgs.gov.  Information on arsenic nationwide is at http://water.usgs.gov/nawqa/trace/arsenic/.

These reports provide information that can be used by private citizens, public health officials and water resource managers. “Our cooperative study tackled some very difficult scientific questions regarding the causes for the distribution of arsenic in ground water. As is often the case, the scientific answers were not simple, and many questions remain,” says Jim Nicholas, chief of USGS’s District Office in Lansing. “Nevertheless, the results remain timely as the new standards for the concentration of arsenic in drinking water, recently promulgated by the U.S. Environmental Protection Agency, take effect. Southeastern Michigan has addressed the issue of arsenic occurrence in a manner that is a model for much of the rest of the country.”

For more information, contact the county health department – Genesee (810-257-3603), Huron (517-269-9721), Lapeer (810-667-0392), Livingston (517-546-9858), Oakland (248-858-1312), Sanilac (810-648-2150), Shiawassee (517-743-2390), Tuscola (517-673-8114), Washtenaw (734-971-4542).  For statewide information, contact Michigan Department of Environmental Quality, Drinking Water and Radiological Protection Division (517-335-9218); Michigan Department of Community Health, (517-335-8350), or USGS (517-887-8903)

As the nation's largest water, earth and biological science and civilian mapping agency, the USGS works in cooperation with more than 2000 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, to contribute to the conservation and the sound economic and physical development of the nation's natural resources, and to enhance the quality of life by monitoring water, biological, energy and mineral resources.

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