BIG RAPIDS -- A common food industry preservative being found in the wastewater from the maker of Ice Mountain bottled water is causing problems with the treatment of municipal wastewater discharged into the Muskegon River.

The preservative, potassium sorbate, is found in the wastewater from the Ice Mountain water bottling facility in Stanwood and is turning up at the treatment plant in Big Rapids.

The chemical is interfering with the plant's ultraviolet disinfection system, bouncing the UV light back toward the lamps and limiting its ability to pass through the water to kill bacteria before being discharged, City Engineer Don Greiner said.

Potassium sorbate is an ingredient in the Splash line of flavored waters from Nestle Waters North America, a branch of Switzerland-based Nestle SA, said Ice Mountain spokeswoman Deb Muchmore. She said the company was working with Big Rapids officials to find a solution.

Ice Mountain trucks some wastewater from its bottling plant to the Big Rapids treatment facility, which discharges treated wastewater to the Muskegon River.

The potassium sorbate problem was discovered in October, when the wastewater plant had a one-week violation of the maximum amount of fecal coliform bacteria released into the river.

Nestle now bottles about 172 million gallons of spring water annually in Stanwood.

It has proposed drawing 216,000 gallons of water per day from a well in Osceola County and says it also is considering a site in Newaygo County that is near the headwaters of the White and Pere Marquette rivers.