Minnesota cities seek more time to reduce salt in wastewater

July 6, 2019 GMT

AVON, Minn. (AP) — Several Minnesota cities are trying to manage a salty, expensive problem.

About 100 Minnesota cities discharge too much chloride — or salt — from their wastewater plants, and 15 plants need to reduce their chloride discharge levels to meet state limits.

But about six cities want more time. Minnesota Public Radio News reports that Avon is the first city to ask for a variance to chloride limits under the federal Clean Water Act. The city is seeking an additional 15 years to find a way to reduce the city’s dependence on salt.


Chloride is a permanent pollutant, and excess amounts can affect fish and aquatic life, as well as the taste of groundwater used for drinking.

In the Twin Cities, road salt used to melt winter ice is the major source of chloride pollution. In smaller cities and towns like Avon, home water softeners that remove minerals from well water — but leave behind a salty water mixture that goes down the drain — is a major culprit. Avon’s wastewater treatment plant isn’t designed to remove the chloride as wastewater is discharged into Spunk Creek, which flows into the Mississippi River.

The city of Morris recently built an $18 million plant that centrally softens drinking water to reduce the need for individual softeners in homes. Fixing the problem in Avon would also cost millions.

“People wouldn’t come to Avon to live,” said Jon Forsell, Avon’s public works director. “Taxes would be way too high.”

The federal Clean Water Act allows for variances in certain situations, including if the process to reduce chloride discharge would cause “substantial and widespread economic and social impact.”

Elise Doucette, a policy specialist with the Minnesota Pollution Control Agency, said regulators can consider a city’s ability to pay when deciding how quickly it must meet an environmental rule.

“Variances allow for a little bit of flexibility when you have that hardship issue,” she said.

Dealing with chloride is a “really vexing problem” for communities, said former MPCA commissioner John Linc Stine, who now leads the nonprofit Freshwater Society. He said the sources of chloride vary with communities, and he called the variance process a “rational next step” to see if cities can meet standards in ways that are tailored to their situations.

“If they can, then that’s a helpful step forward, rather than using brute force,” Stine said.

If the U.S. Environmental Protection Agency approves a variance, Doucette said, the city would have time to evaluate its options, but also would need to take steps to reduce its chloride pollution during that 15-year period.

“They cannot get worse. They must get better,” she said.


Information from: Minnesota Public Radio News, http://www.mprnews.org