Central Iowa Water Works Shuts Down Nitrate Plant After Record 193 Days of Operation

Central Iowa Water Works (CIWW) has turned off its nitrate removal facility after a record-setting 193 days of continuous operation, raising urgent questions about water quality, farming practices, and the cost to taxpayers.

Amy Kahler, CEO of Des Moines Water Works, announced on July 25 that the plant was shut down on July 23. The previous record was 177 days in 2015. The plant had been running virtually all year to meet federal safe drinking water limits for 600,000 central Iowa customers.

Why Did the Nitrate Plant Run So Long?

High nitrate levels in the Des Moines and Raccoon rivers drove the extended operation. Data from the U.S. Geological Survey showed nitrate levels in the Raccoon River lingered around 15 milligrams per liter for much of the year, well above the federal safe limit of 10 milligrams per liter. Levels only recently fell to 5 milligrams per liter.

High nitrate levels are dangerous for infants and have been linked to some cancers. Iowa has the nation's second-highest cancer rate and is one of only three states with rising new cancer rates.

Farmers Push for Voluntary Conservation

Three north Iowa farmers known as the Lobe Rangers are urging fellow growers to adopt conservation practices to reduce fertilizer runoff. Matt Bormann, Zack Smith, and James Hepp held their first field day on July 25 to promote cover crops, in-season nitrogen application, and reduced tillage.

“We're trying to point out simple things that are obvious, but work,” Bormann said. “None of this costs us yields or hurts our bottom line. We're still in business. We're not broke. We're proof that it works.”

Bormann warned that farmers could face government regulations if they don't adopt these practices voluntarily. “We have too many people who are choosing not to play ball,” he said.

Cost of Treatment vs. Conservation

State Sen. Dennis Guth questioned whether treating nitrates at the plant is more cost-effective than investing in conservation practices. He cited an agricultural engineer who estimated the cost at about $2 to $3 per person per year.

Kahler said the nitrate removal plant cost $1.6 million last year, though final costs for 2025 haven't been calculated. The Iowa Nutrient Reduction Strategy estimates it would cost about $750 million annually over five decades to meet the state's goal of cutting nitrogen and phosphorus levels by 45%.

Farmer participation remains voluntary and is encouraged through state incentives. Critics say progress is too slow. The strategy calls for about 13.8 million acres of cover crops, but only about 3.8 million acres were planted in 2023.

Lawn Watering Ban Lifted

CIWW banned lawn watering on June 8 due to spiking demand that threatened to outstrip treatment capacity. The ban was lifted for residential customers on July 1 and for businesses and governments on July 20.

What About Rural Wells?

Catherine DeLong, Iowa State University Extension's water quality program manager, noted that treatment plants don't help rural residents who rely on wells. “They're the ones directly accessing source water,” she said, urging annual well testing through Iowa's counties.

State Funding for Upgrades

In May, Gov. Kim Reynolds announced a $25 million grant to expand and upgrade CIWW's nitrate removal facility, part of a statewide overhaul of water quality funding.

Kahler emphasized that relying on utility treatment doesn't improve the health of Iowa's rivers, lakes, and streams. “We need to address the problem at its source,” she said.