How Lake County uses molasses to protect aquatic wildlife (more than usual)

Molasses generally isn't the first thing that comes to mind when discussing wastewater treatment, but it is an essential part of the process in Lake County.

The purchase of $55,000 worth of the syrupy product was discussed at Wednesday's meeting of the Lake County Board's public works, planning and transportation committee and was quirky enough that Interim Public Works Director Austin McFarlane was asked to explain the request.

"We've been using this system since around 2015 when our Mill Creek facility came online," he said.

Public works wants to contract with Quality Liquid Feeds Inc., of Dodgeville, Wisconsin, for molasses to use at the Des Plaines River, New Century Town and Mill Creek wastewater treatment facilities.

Molasses is used as a carbon source to sustain the biological process used to reduce phosphorous from the treatment plants' discharge into bodies of water, McFarlane said.

It initially was used at Mill Creek, but the need increased after the nutrient-removal process was installed at the other facilities, according to McFarlane.

He explained that specialized bacteria, known as phosphorous-accumulating organisms, depend on a constant supply of carbon to ensure they work. Molasses provides that food for the bacteria.

"We want to make sure there's a constant supply - that helps us in the long run," McFarlane said. "It's a cheaper way to go than chemicals."

The amount of phosphorous contained in effluent from wastewater plants is regulated as part of wastewater discharge permits issued by the Illinois Environmental Protection Agency. High levels in bodies of water can lead to excess algae and aquatic plant growth, harming aquatic wildlife.

Quality Liquid Feeds is the sole source of the product, and the contract was recommended for approval by the full board next week. The company has been serving the agricultural community for 42 years, said Sabrina Yanke, district sales manager, and has branched into other markets.

"We have found molasses in combination (with) other ingredients to be a great source in feeding microbes whether in the stomach of an animal, in the soil or in wastewater," she said.

But you won't find this form of molasses on store shelves. Steve Freeman, research manager for Quality Liquid Feeds, developed the formula used by Lake County.

"It's not just molasses. It's a fermented product with multiple ingredients," such as added proteins, minerals and vitamins, he said.

Molasses is introduced to raw sewage as it enters the treatment plant. When waste entering the treatment plant has a low concentration of carbon, the ability of the system to remove phosphorous decreases.

That usually happens in summer when school is out, according to McFarlane. But at the New Century Town facility near Vernon Hills High School, the carbon dropped much sooner than expected because restaurants, schools and businesses closed during the COVID-19 pandemic, he said.