DES MOINES, Iowa (AP) - Des Moines Water Works plans to double the size of the nitrate removal facility that treats drinking water from the Raccoon and Des Moines rivers.
The Des Moines Register reported (https://dmreg.co/2qZ3MN3 ) that the utility’s board this week approved an $800,000 design contract. The utility expects to spend $15 million on the project, and officials said the new equipment and the cost to operate it will require bigger future rate increases.
The original nitrate facility was constructed for $4.1 million in 1991. It has eight large tanks that can process 10 million gallons of water per day and are used when nitrate levels are so high that there’s not enough water to dilute the compounds. Federal drinking water standards require levels to be below 10 milligrams per liter.
The utility turned on the equipment for the first time this year on Sunday. Company spokesperson Laura Sarcone said that despite high river levels because of rain, nitrates were at 12 milligrams per liter on Tuesday.
“If nothing happens in the watershed, we could see (25-30) milligrams per liter at Fleur Drive. So we have to plan for that now, because it could take a while for construction,” Sarcone said.
The utility sued three northern Iowa counties, accusing them of allowing agricultural drainage districts to send nitrate pollution into the rivers. A federal judge dismissed the lawsuit in March, saying Iowa’s water quality problems were an issue for the Iowa Legislature. The lawsuit sought damages for the money the utility has spent to remove the nitrates.
According to a 2016 report from CH2M, an engineering consultant based in West Des Moines, nitrate levels in the rivers have been increasing and are expected to continue to rise.
“Now that the lawsuit is gone … we have to presume the trend will continue upward not downward,” Water Works CEO Bill Stowe said.
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Information from: The Des Moines Register, https://www.desmoinesregister.com
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