State agency to hold virtual public meeting on Lewiston wastewater plant

The Minnesota Pollution Control Agency set limits on chloride effluent levels from the Lewiston wastewater treatment plant, pictured above.

Minnesota Pollution and Control Agency staff will host a virtual public input session at 6 p.m. Tuesday, June 6, about chloride regulations on the Lewiston wastewater treatment plant.

The Minnesota Pollution Control Agency assigned limits on the amount of chloride the facility can discharge while the city was reapplying for a permit.

Tuesday's virtual meeting focuses on a variance that allows the facility to meet interim chloride levels higher than the agency's goals.

"The city doesn't have the ability to comply with those limits right away. So the variance is going to allow the city to do some chloride source reduction while making sure the water quality standard is going to be met in the future," said Fawkes Char agency policy specialist.

The city must comply with other conditions, including creating a chloride investigation and minimization plan that identifies sources of chloride and immediate chloride reduction actions, and a review of the variance every five years.

The Minnesota Pollution Control Agency plans to recommend the variance, which needs final approval from the EPA.

Chloride, one of the chemical compounds in salt, harms fish, insect and plant life when present in large amounts according to the Minnesota Pollution Control Agency. Wastewater facilities are not designed to filter out salt. Effluent from the Lewiston facility flows into Rush Creek.

While multiple sources contribute to chloride in wastewater, in-home water softener salt is a large source across the state, said Char.

Water softeners are desired by many in southern Minnesota because of "hard" water with high amounts of minerals drawn from aquifers in the region.

Communities can reduce chloride effluent from wastewater treatment facilities by creating a central softening system and having residents uninstall in-home softeners.

"As one might imagine, that solution is extremely costly when you’ve got small communities, the people that are living in those communities, that are paying the user fees that cover those infrastructure costs," said Char.

Given median household income in the area and the estimated cost of a central water softening facility, the Lewiston facility qualifies for a variance under EPA and Minnesota Pollution Control Agency.

The 15-year variance is designed to allow communities to find funding for infrastructure work to reduce chloride entering wastewater, or finding another solution such as finding a new municipal water source.

"There are some creative solutions, it's not cookie cutter in every case," said Char.

When: 6 p.m. Tuesday, June 6

Where: Online only

Link: www.pca.state.mn.us/events-and-meetings/city-of-lewiston-variance-request-chloride-in-wastewater-2023-06-06

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