City has to tighten sewage pretreatment process

A survey will go out on March 1 to tally what hazardous materials are stored at Kalispell businesses.

Kalispell's sewage treatment plant is doing the survey so it can track what substances are going into the sewers and to help businesses dispose of fluids that would harm the plant.

The plant's staff hopes to get the initial survey back by April 1. Then plant chemist Rebecca Bodnar, who also is the new pretreatment program coordinator, will visit businesses to check and help with their hazardous materials disposal programs.

By summer, an expansion of Kalispell's sewage treatment plant will be completed that will increase its capacity from 3.1 million gallons a day to 5.4 million gallons daily.

Exceeding the 5-million-gallon figure means that federal law requires the city to increase its regulation of materials that go through the sewage treatment plant.

The increased regulation, including more sampling, is supposed to be in effect by September.

Excessive phosphorus, ammonia and other chemicals, plus dissolved oxygen, can result in the plant's discharges being higher in chemicals that can harm the environment, said Joni Emrick, the plant's supervisor.

The substances also can cause spikes in nutrients leaving the plant. Nutrients increase algae growth in the Flathead River and Flathead Lake with harmful ripple effects.

Other possible effects:

n Excessive amounts of some substances can kill the bacteria that literally eat harmful material in the sewage.

n The plant's pipes could be more likely to corrode.

n Toxic vapors could be produced.

n More heavy metals could end up in the sludge -exceeding the levels that Glacier Gold in Olney will accept as it uses the sludge to create compost.

With the first survey and the follow-up visits, Emrick and Bodnar expect to set up a database of who produces what and how it is disposed. Right now, city officials do not have a grasp on the volumes, chemicals and disposal methods that the survey will reveal.

They expect that most businesses already will have disposal methods in place.

Bodnar expects to work closely with the businesses without proper disposal methods to help those firms find solutions.

A major gap in the program is the lack of enforcement tools.

That will be addressed when the city staff presents a draft sewage pretreatment code to the City Council, likely this summer, they said.