Water Works nitrate removal hits record 111 days

The Des Moines Water Works said Thursday it has run its nitrate removal facility a record-breaking 111 days this year, outpacing the 106 days the equipment was needed in 1999.

The utility said it sees "no clear signs of suspending operation," and it blamed continuing high nitrate levels in the Raccoon and Des Moines rivers on Iowa's farming industry.

Utility officials said the nitrate levels are now 15.31 milligrams per liter in the Raccoon and 16.28 milligrams per liter in the Des Moines rivers. Federal law requires that nitrates in finished drinking water must not exceed 10 milligrams per liter.

In January, the Des Moines Water Works sued drainage districts in three northern Iowa counties, claiming the tiles there act as a conduit that accelerates the movement of fertilizer from farm fields into Iowa waterways, contributing to high nitrate levels in the Raccoon River, a source of water for 500,000 residents.

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High nitrate levels can be deadly to infants younger than 6 months without medical treatment.

Farm leaders have said many factors affect nitrate levels in Iowa waterways, including heavy rains the state has seen this spring. They've argued for time to implement conservation practices, such as cover crops, outlined in the state's Nutrient Reduction Strategy. The voluntary strategy was adopted in 2013 and seeks to reduce rural and urban nitrogen and phosphorus loads statewide, both by 45 percent.

Bill Stowe, CEO of Des Moines Water Works, has slammed the state plan.

"Continued insistence from state and industry leaders that voluntary measures work under the Iowa Nutrient Reduction Strategy ignores the 500,000 central Iowans who must now pay to remove pollution from their drinking water," he said.

The utility said it cost about $900,000 in treatment costs and lost revenues in 2013 to battle high nitrate levels, "and 2015 costs may easily exceed that."