September 18 is World Water Monitoring Day
Since the national drinking water standard for arsenic became more stringent in 2006, arsenic in Illinois groundwater has become a health concern, especially for private well owners. Community water supplies are government-regulated, but private well owners must monitor their own water for safety, according to Brian Kaiser, associate chemist at the Illinois State Water Survey Public Service Laboratory at the University of Illinois Institute for Resource Sustainability.
The Public Service Laboratory (PSL), which tests Illinois citizens' water samples for levels of arsenic, as well as other elements such as nitrates, fluoride, lead, and iron, has received more calls in recent years requesting arsenic testing.
Dissolved arsenic, found in groundwater in some areas of Illinois, is considered toxic. Ingesting low levels of arsenic in drinking water over time may result in chronic health conditions, particularly cancer and heart and nervous system damage.
"What many well owners may not realize is that arsenic occurs naturally in various parts of Illinois, particularly in central Illinois where glacial till is prevalent," Kaiser said. Counties with higher arsenic levels in water have included McLean, Piatt, and De Witt.
Citizens who contact the PSL discuss water quality issues with an analytical chemist and receive a free water sample collection kit with instructions. Once testing is complete, the PSL sends an analysis report, highlighting unusual findings, and provides suggestions on how to correct the problem.
In the case of excessive levels of arsenic, the PSL may suggest that residents first ensure that their water softener is working properly.
Water softeners can protect against some levels and types of arsenic that have combined with undissolved iron or other particles in water; however, additional treatment may be needed. Other options include installing reverse osmosis or distillation equipment, or drinking bottled water.
Citizens should become knowledgeable about water filters before buying equipment because some are better than others at removing arsenic, Kaiser said.
"A misconception about water filters is that they remove all potentially dangerous elements so water is safe to drink," he said. "Some filters remove only physical particles, but do not filter out dissolved compounds, such as arsenic, lead, and copper. Equipment that demineralizes water may be needed to remove arsenic."
Health departments typically recommend that well owners have their water tested annually, since no regulatory agency monitors the water quality of private water supplies.
Residents on municipal water systems probably do not need to have testing performed unless an advisory is issued by their water supplier or recommended by their health care professional. Water suppliers perform frequent testing to ensure compliance with the Safe Drinking Water Act.
The Public Service Laboratory at the Illinois State Water Survey provides Illinois residents with water sample analyses for their private drinking water supplies. Arsenic is routinely determined for water samples. The PSL is located in Champaign, IL, and can be contacted at (217) 333-9234; http://www.sws.uiuc.edu/chem/psl/