The North Raccoon River routinely has elevated levels of nitrate contamination. โ€” Jared Strong/Iowa Capital Dispatch

It has been almost a year since Central Iowa Water Works (CIWW) had to impose an unprecedented outdoor watering ban on the 600,000 residential and business customers it serves in the Greater Des Moines area and beyond because of the high levels of nitrate pollution in the Raccoon and Des Moines rivers. Now, the water utility is asking it customers to voluntarily reduce outdoor watering by 50 percent.

Once again, the cause of the problem is high nitrates in the areaโ€™s primary sources of water. 

โ€œCentral Iowa continues to face significant water quality and operational challenges,โ€ CIWW Executive Director Tami Madsen said in a statement on Wednesday. โ€œAdditional conservation efforts are necessary to help reduce stress on the system and support reliable drinking water service for the region.โ€

According to the utility, the sustained high nitrate levels โ€œhave limited CIWWโ€™s ability to fully replenish summer reserves and required earlier, more strategic use of stored supplies. CIWW is actively managing operations to maintain reliable service, reinforcing the importance of thoughtful water use across the region.โ€

The Stage II Water Alert CIWW issued on Wednesday, calls for 50 percent reduction in lawn watering, prioritizing โ€œessential outdoor use only,โ€ and generally using water โ€œwiselyโ€ indoors as well as outdoors. All these measures are voluntary. 

CIWW is also encouraging people to limit lawn watering to two days a week with even-numbered addresses watering on Sunday, Wednesday or Friday, and odd-numbered addressed watering on Tuesday, Thursday or Saturday. and asking people to avoid watering on Mondays, because that day sees the highest demands on the system.

If the Stage II measures donโ€™t reduce stress on the system and nitrate levels in the rivers remains high, which they typically do in summer, CIWW could issue a Stage III Water Warning, which includes a ban on lawn watering at residential properties, and most business and government properties. 

Central Iowa Water Works

CIWW created its new five-stage water use plan system after last summerโ€™s water ban, which lasted from June 12 until Aug. 7. The stages range from Stage 0, which involves normal water conservation practices, to Stage IV, an emergency situation that necessitates water rationing. 

Elevated nitrate levels in the Raccoon and Des Moines Rivers have been a problem for CIWW since the beginning of the year. Normally, CIWW doesnโ€™t need to operate its nitrate removal facilities during the winter, but this year it was necessary to activate them on Jan. 6. It was the first time since 2015, and only the second time overall, that the nitrate filtration system needed to be activated during the month of January. 

CIWWโ€™s nitrate filtration system ran continually from Jan. 6 to March 2. It needed to be reactivated seven days after shut-off. Operating the system can cost up to $16,000 a day. 

The Iowa Women of Achievement Bridge stretches over the Des Moines River in January 2023. โ€” Adria Carpenter/Little Village

According to federal safety standards, the nitrate levels in drinking water cannot exceed 1 mg per liter. On Wednesday, the nitrate level in Raccoon River was 17.17 mg/l, and in the Des Moines it was 10.4.

The federal safety standards for nitrate levels in drinking water was set in 1963 to address the problem of โ€œblue baby syndrome,โ€ a condition in which nitrate exposure causes dangerously low blood-oxygen levels in newborns and infants. There is a consensus among scientists that the level needs to be lowered to help prevent other known health problems associated with nitrates in drinking water. Many say it should be half the current level, some say it should be even lower.

Multiple peer-reviewed studies have linked long-term, low-level exposure to nitrates in drinking water to health problems, including birth defects and some forms of cancer. โ€œCurrents of Change,โ€ a 232-page report summarizing the findings of a two-year scientific study of the Raccoon River and Des Moines River water quality, found โ€œthe highest nitrate values [in drinking water sources] nationwide are predominantly found in Iowa.โ€

A nitrate test kit provided by the Izaak Walton League of Iowa via Nitrate Watch is used to test Ralston Creek in southeast Iowa City. โ€” Emma McClatchey/Little Village

According to the report, nearly 80 percent of the nitrate pollution in the Raccoon and Des Moines came from agricultural runoff. Even though the general extent of the problem has known in Iowa for decades, the state government has done little to address it, and does not permit local governments to take action to do so. Instead, it has asked farmers and agribusinesses to voluntarily take actions to address the problem. 

On May 1, Gov. Kim Reynolds announced what she called a โ€œfarm to faucetโ€ water quality funding package. It consisted of a series of measures inserted into this yearโ€™s agriculture and natural resources appropriation budget in a last-minute amendment. On the farm side, it provides new funding for voluntary measures. In addressing what flows from faucets, it provides a one-time payment of $25 million to CIWW to help cover the cost of expanding its nitrate filtration capacity. 

Gov. Kim Reynolds, Iowa Secretary of Agriculture Mike Naig and then-Rep. (now Iowa AG) Brenna Bird in a photo posted to Reynolds’ official Twitter account on March 3, 2023.

Iowa Ag Secretary Mike Naig stood next to Gov. Reynolds as she made her farm to faucet announcement. Naig, a Republican who has been in office since 2022, is running for reelection this year in an election in which the state’s inaction on water quality and its failure to effectively address its ongoing cancer crisis are likely to be major issues. Naigโ€™s opponent is Democrat Chris Jones, an expert on water quality issues and one of the stateโ€™s leading advocates for fundamental reforms to the stateโ€™s approach to agriculture in order to address problems like nitrate pollution. 

โ€œThe Naig/Reynolds scheme (dubbed as Farm to Faucet) focuses mainly on drinking water and wastewater infrastructure, especially infrastructure for nitrate mitigation,โ€ Jones wrote on his Substack after the governorโ€™s announcement.  โ€œReynolds and Naig each have been in office for nearly a decade, with Naig coming to state government after lobbying our government as a Monsanto representative. Theyโ€™ve done nothing to change the fact that one-third of Iowaโ€™s 1077 community water systems are vulnerable to nitrate contamination, or to protect Iowaโ€™s private drinking water wells, 6600 of which (that we know of) have been contaminated with the pollutant. Municipal drinking water in many of Iowaโ€™s large and medium-sized cities is impacted by nitrate pollution including the Des Moines metro, Cedar Rapids, Iowa City, Cedar Falls, Waterloo, Ottumwa, Manchester, Independence and Boone.โ€

Jones called โ€œfarm to faucet” the Reynolds administration’s โ€œlatest water quality con.โ€

A sign reading “no to nitrates” is held up at a rally for clean water at the Iowa Capitol Feb. 19. 2026. The Iowa Water Quality Information System did not see proposed funding from the state pass this legislative session, leading the program to rely on county and city funds. โ€” Cami Koons/Iowa Capital Dispatch