May 25, 2010
Health Department releases annual report of drinking water in Minnesota
Results of regular monitoring reveal little evidence of contamination problems in Minnesota's 964 community water supply systems, according to the Minnesota Department of Health (MDH).
Minnesota's public water supply systems are tested on a regular basis for bacteria, nitrate and other inorganic chemicals, radiological elements, and up to 118 different industrial chemicals and pesticides. The MDH annual report is based on the results of monitoring under the federal Safe Drinking Water Act for the past year.
The drinking water annual report includes test results for 726 city water systems throughout the state. Also included were 238 non-municipal systems that provide drinking water to people in their place of residence—in locations such as manufactured home parks, apartment buildings, housing subdivisions, colleges, hospitals, prisons, and child care facilities.
Among the other findings in the report:
- No systems exceeded current federal or state standards for pesticides or industrial contaminants. Water samples from those systems were subjected to more than 21,000 separate tests for more than 100 potential contaminants.
- Detectable levels of coliform bacteria were found in 13 community water systems, including 5 municipal systems. While not all coliform bacteria cause illness, they provide an indicator of possible contamination in the system. Systems with coliform problems are routinely disinfected, flushed, and retested to ensure that the contamination is gone before being returned to normal service. The process typically takes less than a week. The municipal systems that tested positive for bacterial contamination were Bovey, Brainerd, Marble, Perley, and Trommald. All of the residents served by the affected systems were informed of the situation at the time it occurred.
- While several cities in Minnesota continue to wrestle with arsenic in their groundwater, the vast majority of municipal drinking water systems in the state report few problems. By the end of 2009, 10 community water systems, including 6 municipal systems, still exceeded the standard for arsenic. The affected municipal systems are Buffalo Lake, Dilworth, Dumont, Lowry, Norcross, and Wendall. These systems are working with MDH to come into compliance and are also communicating regularly with their residents about the situation. Arsenic occurs naturally in soil and rock, where it can dissolve into groundwater, the primary source of drinking water for much of Minnesota. Arsenic can occur in groundwater just about anywhere in Minnesota.
- Ten community water systems—including 8 municipal systems—exceeded the standard for radium 226 & 228 at the end of 2009. The affected municipal systems are Anoka, Brook Park, Claremont, East Bethel, Hinckley, Lewiston, Medford, and Rushford Village. No restrictions were placed on water consumption although residents were notified of the situation. Residents were told that this was not an emergency situation and were advised to consult with their doctors if they have any special concerns. Each of these systems has either started to make infrastructure changes or is studying alternatives to meet the maximum contaminant level.
Minnesota Health Commissioner Dr. Sanne Magnan said she is pleased with the positive results of the testing. "The quality of our drinking water affects the health of all Minnesotans. The monitoring data reflect the dedication and professionalism of the people who operate our community water supply systems as well as the good work of our state's drinking water program," she said. "We can never be complacent about something as important as drinking water quality. We must remain vigilant in our routine monitoring and alert for new challenges."
The 2009 report and those from previous years are available online at http://www.health.state.mn.us/divs/eh/water/com/dwar/report09.html.
Drinking Water Protection