COMBINED LOCKS, Wisconsin (From news reports) -- McKinley Paper's Combined Locks mill has been cited for a permit violation after the Wisconsin Department of Natural Resources observed floating solids in the Fox River, transgressing environmental regulations.
Heidi Schmitt Marquez, wastewater field supervisor with DNR, said the presence of floating solids in the Fox River constitutes a permit violation under Wisconsin Statutes of pollution discharge elimination.
"What we're going for with the prohibition is that if you can see something with your naked eye in the discharge, that means that there's something wrong with the (wastewater) treatment plan or something that's out of the ordinary has happened," said Marquez.
Under the Wisconsin Pollutant Discharge Elimination System (WPDES) permit, paper mills like McKinley Paper are typically allowed to discharge treated wastewater, including cooling water, treated process water, and certain levels of dissolved substances. However, they are not allowed to release floating solids, foam or scum.
Marquez said the department does not know the nature of the floating solids, or the cause of the spill.
"It's a bit of a challenge because we were not able to immediately identify the cause," she said
In a public statement issued through the city of Kaukauna on Feb. 6, McKinley Paper acknowledged the presence of organic by-products from their wastewater treatment system in the Fox River. The company said that the material is not hazardous or harmful, and attributed its visibility to historically low river levels.
"Based on our review to date, the condition is caused by historically low river levels, which are allowing organic material to float to the surface," the company said.
In wastewater treatment, the process begins with the separation of solid materials from liquids. The liquid component is subsequently discharged into surface waters, adhering to environmental regulations. Conversely, the solid component, referred to as sludge, is concentrated by removing excess water. The sludge is often dewatered and transported to landfills for disposal, according to the United States Environmental Protection Agency.
