Update 5/14: In a news release, the City of Cedar Rapids said it is also monitoring nitrate levels in the Cedar River, noting a nitrate monitor upstream of the measured a nitrate level of 18.5 mg/L, which the city’s water utility called “one of [the] highest nitrate levels ever measured in the Cedar River.” At this time, Cedar Rapids drinking water is meeting the EPA’s safe water guidelines.
This afternoon, the Des Moines Water Works officially released details about Last week’s record nitrate levels in both the Raccoon and Des Moines Rivers. According to the release, “This new record follows the continued upward trend of nitrate concentrations since fertilizer use and increased row-crop agriculture began in the mid-1960s. It has been calculated that last week’s nitrate load surpassed last year’s entire nitrate load.”
Bill Stowe, head of the Water Works, has not minced words as he has described the nitrate removal challenge the Water Works faces or its causes.
“The optimal solution to prevent nitrate concentrations from entering our source water is through watershed protection programs and good land management practices,” said Stowe.
“However, the recently published Nutrient Reduction Strategy is inadequate in that it lacks vision, goals, measurable outcomes, or timelines for agricultural (non-point) discharges. Without significant action, Des Moines Water Works will be forced to continue treating degraded source waters, and our customers will continue to pay for that extensive treatment in their rates,” he said.
The Des Moines Water Works is a cooperator member of the Iowa Environmental Council. The Council has also been strongly critical of Iowa’s nutrient reduction strategy, arguing that it lacks clear timetables or standards for measuring success.
A survey of available water quality data by the Iowa Environmental Council Monday showed Des Moines is not the only place where high nitrate levels are being recorded.
At 3 p.m. Monday, nitrate levels were 26.8 mg/L on the Raccoon River near Jefferson, 28.18 mg/L on the Boone River near Webster City, and 17.8 mg/L on the Cedar River near Palo. (Real-time nitrogen monitoring data is provided by the United States Geological Survey.)
The highest recorded nitrate concentration was 40.9 mg/L on Lyons Creek near Webster City.
The EPA’s safe drinking water standard for treated drinking water is 10 mg/L.