IOWA CITY - An ongoing sheen on Ralston Creek in Iowa City has been traced to a seep in the bed of the creek.
City officials placed a boom across the creek to contain the sheen south of the intersection of Burlington and Van Buren streets.
DNR staff on site suspect a petroleum-based source, and collected water samples for laboratory analysis. A DNR inspector has not seen any dead fish or other obvious environmental impacts.
DNR will continue to seek the source of the contaminant, monitor cleanup efforts and consider appropriate enforcement action.