The Iowa Department of Natural Resources is continuing its investigation but has identified the black substance in a tributary to the North Raccoon River in Greene County.

According to the DNR, they were notified this past Monday morning about discolored water in one of the tributaries that feeds into the North Raccoon River two miles east of Cooper in Greene County. DNR officials have identified the black water as hog manure. The report shows that the manure is no longer actively flowing, an unknown amount of manure is still pooling in numerous areas of the tributary that is part of Drainage District tile 37B. 

DNR staff have checked tiles, tile intakes and drainage tile outlets, with local officials and multiple landowners given information about the situation. Field tests have shown the impacted area has dissolved oxygen at zero and ammonia concentrations levels are as high as the field tests allow at 300 parts per million (ppm). Additional water samples have been submitted to the State Hygienic Laboratory for further analysis, which are expected to be completed in the next 7-10 business days. 

Additionally, the public is asked to avoid swimming and recreating in this area and for livestock to limit using the tributary as well. Raccoon Valley Radio will bring you more information as it becomes official.