Tests: Iowa River clear of contaminants from Marengo explosion

Iowa City, downstream of Marengo, asks for analysis because of runoff

Dec. 29, 2022 4:24 pm, Updated: Jan. 26, 2023 10:57 am

Water flows in a ditch Dec. 16 near the C6-Zero facility in Marengo. The ditch leads to a retention pond near the Iowa River. Multiple people were injured in an explosion at the facility that coverts used roofing shingles into base ingredients, including fuel. (Jim Slosiarek/The Gazette)

IOWA CITY — The Iowa River does not show signs of pollution from the Dec. 8 blast at a Marengo workshop that had large stores of petroleum products, officials said Thursday.

The Iowa City Water Division earlier this month took samples of the Iowa River, which is an indirect source of drinking water for the city, after the Iowa Department of Natural Resources reported contaminants from the C6-Zero explosion and fire had run into a stormwater basin in Marengo.

Marengo is upstream of Iowa City.

The State Hygienic Laboratory, in Coralville, analyzed the samples for petroleum products, such as gasoline and diesel fuel, and found “no reportable detection of contaminants,” the city reported.

The city will continue to test the river weekly for the next three weeks.

C6-Zero, a company whose business plan was to dissolve used roofing shingles into base ingredients, had an explosion and fire Dec. 8 that injured up to 15 people and caused an evacuation of homes near the Marengo workshop.

Concerned about runoff of solvent and marine-grade diesel fuel on site, the Iowa DNR took water samples of the nearby retention basin and ordered the company to put up barriers to prevent further pollution.

The state also asked the city of Marengo earlier this month to halt use of a pumping system that moves water from the retention basin to the Iowa River following the explosion. The pumps are connected to a levee that protects much of Marengo from river flooding.

Comments: (319) 339-3157; erin.jordan@thegazette.com