MARATHON COUNTY, WI (WTAQ) - About one of every seven private water wells in Marathon County have tested positive this year for coliform bacteria, which has the potential to cause E-coli contamination.
Marathon County is the state’s largest in terms of land area. County health officials in Wausau say they’ve tested about 1,800 private wells this year, and 14 percent were found to have coliform bacteria.
Environmental health director Dale Grosskurth says the county’s percentage is about what was seen at the state level a year ago. The State Hygiene Lab said about 15 percent of the private wells tested in 2011 had coliform samples. That figure was a high as 20 percent in 2008 and 2010, when the state has massive flooding.
Officials say most coliform bacteria is harmless – but it can be a sign of poor water quality.
Grosskurth said many of this year’s positive tests are from older wells which don’t have the protective caps which are now required by law. He said homeowners that test their wells each year would find it relatively easy to make improvements to come into compliance.
He said the thought of contaminants in drinking water should be enough to encourage people to test their well water each year.