On Monday, Aug. 21, the DNR was notified of a black liquid in an unnamed tributary, approximately 1 to 1 ½ miles from the North Raccoon River. This liquid has been identified as hog manure and the investigation is ongoing.

Although the manure is no longer actively flowing, an unknown amount of manure continues to be pooled in numerous areas in the tributary and in drainage district tile 37B, verified with the Greene County Drainage District.

The public is asked to continue to avoid swimming or recreating in this area. Additionally, it is recommended that livestock using the tributary for watering be limited as well.

Throughout the week, DNR staff have investigated the area by checking tiles, tile intakes, and drainage tile outlets. Additionally, local officials and multiple landowners have provided information. Field tests show dissolved oxygen at zero and ammonia concentrations greater than 300 ppm, which is as high as the field tests read. Water samples have been collected and sent to the State Hygienic Laboratory for further analysis and are expected within the next 7-10 business days.