On Thursday the Des Moines Water Works board moved forward with its plans to sue the supervisors in Sac, Buena Vista and Calhoun counties over the nitrate levels in the North Raccoon River. The lawsuit targets several drainage districts that are managed by the three counties. Weekly samples taken from the river in Sac County since March have shown high concentrations of nitrates, which have triggered costly treatment operations downstream at the Des Moines Water Works facility. Nitrates occur naturally in the soil, but can spike in water when manure and other fertilizers drain into waterways. The Water Works has been running its denitrification facility since early December to reduce the nitrate levels to EPA-permissible levels, at a cost of $4,000 per day.
The lawsuit would be filed in federal court under the U.S. Clean Water Act, which grants regulatory exemptions to nonpoint source discharges, including field tile systems on individual farms. Water Works officials contend that organized drainage districts shouldn’t be exempt from regulations. This case could have far-reaching implications for the control of nonpoint source pollutants from agricultural lands.
The full Des Moines Register story is here.