ANN ARBOR, MI – Over 6,000 gallons of raw sewage is estimated to have spilled into the Huron River last week, Ann Arbor officials report.

Between Feb. 20 and Feb. 22, the city reported two incidents in which raw sewage overflowed into the river.

On Tuesday, Feb. 20, the city reports there was an overflow at a pipe between the north and south inceptor chamber at the Wastewater Treatment Plant at 49 South Dixboro Road.

Two days later, the city reported a second leak at the intersection of Green Road and Fox Hunt Drive, which led to an estimated 6,000 gallons of sewage overland and into Millers Creek, eventually finding its way into the Huron River.

The blockage was caused by tree roots growing into a sewer line. The affected area was covered with lime to kill any bacteria, city officials said.

There are no communities downstream of the plant that withdraw water from the Huron River for drinking purposes, the city said.

The city says the diluting effects of the river prevent any health risks and no recreational areas were affected.

The city notified the Department of Environmental Quality and the Washtenaw County Health Department of the incidents.

Actions to avoid similar instances are being evaluated by plant staff, the city said.