The Indiana Department of Environmental Management is working with the Warsaw wastewater treatment plant to identify and correct problems at the facility in Boggs Industrial Park.

While the cause is not yet known, it appears the plant has been unable to sufficiently treat its waste before discharging it into Walnut Creek, according to an IDEM news release.

Last weekend a fish kill claimed a number of shad in Walnut Creek prompting IDEM to examine the treatment plant's effluent stream. IDEM personnel noted discolored discharge from the plant that included solids. In a plant that is functioning properly, solids should settle out of the waste steam instead of remaining suspended.

Friday, public works superintendent Lacy Francis said the "fines" - tiny particles of sediment that remain after wastewater is heated and filtered - overflowed the sludge tanks into Walnut Creek.

IDEM inspectors suspect the presence of surfactants (a soap material) as a possible contributor to the suspension of solids. Surfactants, which may have come from industrial discharge, can prevent solids from settling during the treatment process.

Low dissolved oxygen levels were observed downstream from the plant and in the Tippecanoe River, to which Walnut Creek is a tributary.

No environmental warnings have been issued for either waterway.

According to wastewater treatment plant supervisor Dick Van Dyne, the spill into Walnut Creek ended this morning.

The facility faced several problems at once leading to last week's troubles, he said.

The sludge tanks were at capacity pending permits for land application. Those permits were approved last week.

Before the land application took place, an unknown soap material (surfactants) entered the tanks, breaking the sludge into bits too small to capture the "fines."

"The soap material is either different from or at levels we haven't had before," Van Dyne said. "IDEM is conducting a CTAS test to determine the surfactant and its quantity. It's something other than what we're used to."

Local industries have their own pretreatment plants that ordinarily remove possible contaminants.

IDEM will track down the source of the suspected surfactants. Samples are on their way to a laboratory in Louisville, Ky., for testing.

Van Dyne is sure the problem is organic, however, and not stemming from an introduction of metal.

"We had to remove the bulk of the sludge from the system in a very short time," he said. "When the sludge is in a young stage, solids don't settle as easily. The bacteria has to grow and accumulate."

It doesn't take a whole lot to mess up the delicate environment of a sludge tank.

Over the weekend, polymers were added to the tanks to attract solid particles, a process known as deflokulation. Currently the sludge is "too young" to attract solids on its own.

It will have to regenerate its own population of bacteria, and that will take several days, the superintendent said.

IDEM is taking the following steps to help stabilize the plant and the creek:

• Using aerators to raise the level of dissolved oxygen in the creek;

• Assisting the treatment plant in removing solids;

• Talking with local industries to determine the composition of the waste stream received by the treatment plant;

• Urging the city to work with industrial discharge to minimize discharges; and

• Monitoring plant activity and efforts to correct the problem and assisting as needed. [[In-content Ad]]