November 21, 2014

High nitrate levels prompt water conservation request

The Des Moines River

The Des Moines River in Des Moines

The head of the Des Moines Water Works has issued what he calls a “very unusual” request for voluntary water conservation. Des Moines residents are being asked to cut back on watering lawns and gardens, not because of drought, but because of pollution in the capital city’s two primary sources of water.

Des Moines Water Works General Manger Bill Stowe says nitrate levels are so high, they can’t purify the water fast enough to keep up. “Although we have a nitrate removal facility, it has a capacity that’s far less than the customer demand that we’re seeing,” Stowe says. “We can’t denitrify, we can’t make that water safe quickly enough, if people continue to irrigate at the levels that normally we would anticipate.”

Nitrates from farm runoff and other sources reached record levels in the rivers in June. Stowe calls the circumstances unprecedented. “The duration of this event and the seriousness of the water pollution in both the Des Moines and Raccoon (Rivers) are extraordinary for us. That is why this is a very unusual kind of request,” Stowe says.

Des Moines Water Works has been running its nitrate removal facility for two months at a cost of more $330,000. Just as with water shortages, officials are asking residents not to water lawns and gardens in the middle of the day, and to alternate outdoor watering on even and odd days. Stowe says unless water use is cut back, the city may not be able to meet EPA limits on nitrates in the water.