Arsenic contamination of groundwater is becoming an issue of increasing concern in Wisconsin. Ninety-seven percent of the state’s inland communities—70 percent of the state’s population—depends on groundwater for their drinking water. In densely populated areas, the pumping of increasingly high volumes of groundwater has resulted in a lowering of the water table and the drilling of deeper wells. This combination of lower water tables and deeper wells is contributing to elevated levels of arsenic in drinking water, particularly in northeastern and southeastern parts of the state.

While modern water treatment methods are extremely efficient at removing pathogens and many toxic trace metals, most treatment techniques do not effectively remove the toxic inorganic forms of arsenic from drinking water. Arsenic contamination of groundwater supplies is an emerging problem not only in Wisconsin, but in other parts of the United States and other areas of the world.

In 2006, the EPA set the arsenic standard for drinking water at .010 parts per million (10 parts per billion) to protect consumers served by public water systems from the effects of long-term, chronic exposure to arsenic. Recent studies in Wisconsin, Minnesota, Michigan and four other states indicate groundwater arsenic concentrations exceeding 10 ppb are more common and widespread than previously recognized.

Research has shown that people who drink water containing high levels of arsenic over a period of several years have a higher risk of developing cancers of the bladder, lungs, skin, kidneys, nasal passages, liver and prostate. Drinking arsenic-contaminated water can also contribute to cardiovascular and pulmonary disease, immunological and neurological disorders, and adult-onset diabetes.

For those interested in learning more about this issue, here are a few recommended books from our collection. There is also a list of Web sites below that can get you started on the Web.