The Iowa Department of Natural Resources is investigating a lactic acid spill that occurred near Adair Tuesday night.

According to the District 4 DNR Office in Atlantic, a semi-trailer caught fire in the eastbound lanes at the Interstate-80 rest area near Adair. DNR Officials said in a press release that the driver noticed that the tires of the trailer were smoking and pulled over at the rest area, and attempted to extinguish the fire, but was unsuccessful. The DNR authorities say the Adair Fire Department was dispatched and responded quickly, and observed that a majority of the trailer and its contents were on fire. The DNR says the semi was hauling lactic acid, and it’s estimated that approximately 550 gallons of lactic acid were lost due to the fire and the work done to put out the flames.

According to the DNR, Iowa Department of Transportation crews implemented sand to contain the acid, but with the mixture of water, much of it flowed through two storm drains, off the concrete and into an adjacent field, traveling approximately 200 feet before entering a tile line that feeds into a tributary of the South Fork Middle River.

The DNR says that an environmental clean-up crew was on scene around 8pm Tuesday night, and collected samples while beginning the sanitization process. Contaminated soil will be excavated and treated on site as well. DNR Officials say the rest area will remain closed until the clean up is finished, and farmers with cattle downstream should avoid letting them drink from the river. According to the DNR, no dead fish have been reported at this time, but the investigation remains ongoing. Raccoon Valley Radio will bring more information as it becomes official.