Chaska welcomed the new Northern Star Co. potato processing plant and its 400 jobs with open arms 18 months ago, but it didn't expect loud flushing sounds in the middle of the night.
The company violated state noise limits at least six times during April, city officials said. Company and city officials planned to meet again this week to try to resolve the problems.
"We just get noise day and night," said Bruce Perkins, one of six homeowners who lives near the plant on Chaska's northern edge, near the Minnesota Landscape Arboretum.
Perkins described the sound as "a sharp, loud, mechanical flushing noise" that's as startling as a gunshot. It occurs irregularly, from once every five or 10 minutes to several times per minute. The noise may stop for minutes or hours, he said, and then begin again, waking up the neighborhood or keeping people awake as they try to drift off to sleep.
The company is a division of Michael Foods Inc. and had a history of odor and noise problems at its former Minneapolis plant.
Its operations in Chaska make a line of refrigerated potato products called Simply Potatoes that includes hashbrowns, mashed potatoes and other side dishes.
Northern Star purchased, updated and expanded the old Mammoth building along Hwy. 41 in late 2008, and began operations in late January 2010.
Company spokeswoman Diane Sparish said a consultant hired by Northern reviewed the "raw noise data" collected by the city and concluded that the firm has not violated any noise standards. Sparish said Northern has nevertheless installed silencers and pressure-relief valves and taken other steps to reduce noises.
"We're a manufacturing facility operating on land that is zoned for industrial use. We're putting extra measures in to be a good neighbor. But we are running a business and we are compliant," she said.
Chaska City Administrator Matt Podhradsky said he and city council members have received numerous complaints about noise from the plant.
Initial sound testing did not show a problem, but Podhradsky said the city conducted a more intensive study in April that measured noise at levels above state standards. The violations occurred on half a dozen occasions at night, he said.
The city put Northern Star on notice last month that it needs to deal with the problems, and city officials met with company representatives last week.
They decided that technical sound experts from both sides need to review the noise data together.
"We're trying to put some sense to it," Podhradsky said. "The company indicated that if there's an issue with them being out of compliance, and there's common agreement on that, that they would move forward and deal with those issues."
Perkins said that he and other neighbors have been complaining for months and are frustrated as much by the city's slow response as by the company's "stalling tactics." He said problems also include odors and other noises.
Huge fans at the factory aimed towards the neighborhood sound like a freight train, he said, and semi-trailers with rumbling diesel motors idle for hours every night in the company's back parking lot, waiting to dump truckloads of potatoes between 3:30 and 5:30 a.m.
Perkins and his wife Sharon said they built their home in the rural residential area more than 22 years ago and had no problems with the previous company that used the building to assemble large air-conditioning equipment.
"Peace and quiet and living near the woods was precious," Sharon Perkins said. "It was taken from us without our consent. "
Tom Meersman • 612-673-7388