sentences:  The remaining 15% serves to bridge other funding sources that make up the operating budget.In 2011, three environmental groups sued the US EPA to bring DNR's Concentrated Animal Feeding Operations (CAFO) program into compliance with the Clean Water Act.In January 2015, the Des Moines Water Works declared its intent to file a lawsuit against three Iowa counties Buena Vista, Sac, and Calhoun county where groundwater water tests had shown nitrate levels as high as 39.2 mg/L, which was 4 times the federally required Safe Drinking Water Act limit of 10 mg/L as the DNR continued not to enforce the Clean Water Act.