Minnesota Cities Gear Up To Treat Dioxane

More and more Minnesota communities are investing in methods to treat dioxane contamination.

“Our 10,000 lakes are quickly freezing into ice. Still, cities across the metro are becoming increasingly aware of an emerging contaminant found in some of Minnesota's water sources,” KSTP reported.

Dioxane, a water pollutant that can be difficult for utilities to treat, makes its way into waterways from discharges at manufacturing plants, from leaks in underground storage tanks at hazardous waste sites, and from common consumer products such as shampoo and detergent. Some manufacturers, including Tide-maker Procter & Gamble, have made high-profile efforts to reduce 1,4-dioxane in their products.

St. Anthony is among the Minnesota communities investing in dioxane treatment.

“All the drinking water in St. Anthony comes from the ground, so when elevated levels of the chemical 1,4-dioxane showed up in one of the wells, the city had to find a fast solution,” KTSP reported.

As city engineer Todd Hubmer put it, "We really don't have an alternative water supply. We immediately shut down the one well that was over one part per billion and we operated the other two wells.”

Water pros were able to track the contamination to the Twin Cities Army Ammunition Plant, where traces of the contaminant were found.

"You knew a plume would get here eventually so it was better to be proactive," said St. Anthony Mayor Jerry Faust, per KTSP.

The city responded by beefing up its treatment processes.

“In a matter of months, with funding from the Army, St. Anthony built the state's first advanced oxidation process plant and got it up and running before levels of 1,4-dioxane ever exceeded the EPA's guidelines,” the report said.

“The process uses UV light to clean the water and it isn't specific to only 1,4-dioxane. If new contaminants are discovered in the future the plant is likely already ridding the water of those too,” the report continued.

The U.S. EPA says dioxane is a likely human carcinogen. The government also acknowledges that dioxane is difficult to treat. The EPA, in its handbook on how to handle the contaminant, notes that 1,4-dioxane is “fully miscible in water.”

“As a hydrophilic contaminant, it is not, therefore, amenable to the conventional ex situ treatment technologies used for chlorinated solvents. Successful remedial technologies must take into account the challenging chemical and physical properties unique to 1,4-dioxane,” it continued.