Drinking water notebook: Bloomington says water color issues are aesthetic, caused by minerals; plans flushing

Some complaints logged in Bloomington’s uReport system over the Fourth of July weekend describe Bloomington’s drinking water as yellow or brown.

One resident wrote: “When I filled our bathtub tonight I noticed the water coming out of out faucet is light green and there is plant matter floating in it. … This has not happened since we have lived in this house the past 3 years.”

The staff at the Starbucks on Indiana Avenue wrote in part:

We … monitor our water filtration system regularly and normally need to change the filter every 3-4 months (filters are rated to last up to 6 months but they ask us to change them once they become “latte colored”). Saturday 6/28, we found that our water filter was nearly completely black despite being only 1 month old.

Based a plot of the seven complaints, they don't appear to be confined to one area. A map in included below.

A response from CBU indicates that the issues are aesthetic, due to naturally occurring substances, and that the water is safe.

Specifically, City of Bloomington Utilities (CBU) communications manager Daniel Frank responded to an emailed B Square question indicating that the issue is due to naturally occurring minerals in Monroe Lake, the source of the city’s drinking water. There’s currently seasonal uptick in minerals like iron and manganese, Frank wrote, something that CBU routinely tracks and treats.

This year, Frank continued, dealing with the issue has been more challenging due to high water levels at the lake this year. The Army Corps of Engineers is trying to let as much water through the dam as possible, while still preserving the purpose of the dam, which is to mitigate flooding downstream.

Frank also said that temporary repairs to the city’s water treatment system were done last week. About the temporary repairs, Frank wrote, “The plant is fully operational and the data we have so far has met all health and safety standards.”

This coming week, Frank wrote that CBU will be doing additional hydrant flushing at certain points in the distribution system, to address the aesthetic concerns. Extensive sampling throughout the distribution system will be done to confirm CBU has addressed the issue, Frank wrote.

According to Frank, CBU will issue a new release after the data from the sampling has been analyzed.

Last week, the city of Bloomington issued a news release announcing the release of its annual drinking water report.