Central Iowa Water Works (CIWW) has lifted all restrictions on outdoor watering. The utility, which provides water to 20 percent of the state’s population, imposed a ban on lawn watering on June 8.
“The lawn watering ban is not due to a lack of water in our rivers or reservoirs,” CIWW said in a news release when it imposed the mandatory restrictions. “Instead, it is necessary because ongoing source water quality challenges are limiting how much water can be treated and delivered while continuing to meet all Safe Drinking Water Act requirements.”
Lawn watering is the biggest discretionary use of water during the summer months, accounting for up to 40 percent of water use. CIWW issued its first-ever lawn-watering ban last year. Like last year, the prohibition on watering this year was the result of elevated nitrate levels in the water sources CIWW relies on: the Des Moines River, the Raccoon River and CIWW’s infiltration gallery (“a perforated pipeline under Water Works Park used to collect and naturally filter water from the Raccoon River,” the utility explains). Federal safety standards limit the amount of nitrates in water for human consumption to 10 mg per liter.
Elevated nitrate levels in the Raccoon and Des Moines rivers have been a problem for CIWW since the beginning of the year. Normally, CIWW doesn’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.
Nitrate levels remained high throughout the months that followed. Last Thursday, nitrate levels dropped to the level the federal government considers safe for drinking water, allowing CIWW to shut off its nitrate removal facility. The nitrate removal facility has been in use this year for a record-setting 193 days. There were only 10 days between Jan. 1 and July 23 when the facility wasn’t running. The previous record for the most number of days operating the nitrate removal facility during an entire year was 177 days, set in 2015.
After last summer’s watering ban, CIWW created a five-stage water use plan system. The stages range from Stage 0, which involves normal water conservation practices, to Stage IV, an emergency situation that necessitates water rationing.
On May 27, CIWW issued a Stage II Water Alert, which calls for a voluntary 50 percent reduction in lawn watering, prioritizing “essential outdoor use only,” and generally using water “wisely” indoors as well as outdoors. With the system that provides water to 600,000 Iowans still under stress and nitrate levels in its sources of water remaining high, CIWW elevated the alert status to Stage III a week and a half later.
Stage III restrictions prohibit lawn watering at residences, businesses and government facilities “except for newly installed sod or seed placed during the current growing season,” which can be watered the minimum amount necessary for the sod or seed to become established. Athletic fields and golf courses can also be watered “the minimum necessary for safety and plant preservation.”
CIWW ended the watering ban for residential customers on July 1, reverting to a Stage II voluntary 50 percent reduction in outdoor water use for homeowners and renters. The mandatory ban for businesses and government facilities remained in place until last week, when CIWW returned those customers to Stage II as well.
On Monday, CIWW ended “all mandatory and voluntary water use restrictions.”
“While mandatory and voluntary water use restrictions have ended, CIWW encourages customers to continue practicing everyday water conservation habits that help ensure a reliable and resilient water supply for the region,” the utility said in a news release. “… CIWW will continue to closely monitor river conditions, water quality, and regional water demands throughout the remainder of the year.”
The federal safety standards for nitrate levels in drinking water was set in 1963 to address the problem of “blue baby syndrome,” 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, while 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. “Currents of Change,” a 232-page report summarizing the findings of a two-year scientific study of the Raccoon River and Des Moines River water quality, found “the highest nitrate values [in drinking water sources] nationwide are predominantly found in Iowa.”
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 been 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.
CIWW’s cancellation of voluntary water restrictions on Monday coincided with the beginning of the Izaak Walton League of America’s first Nitrate Pollution Awareness Week. The league, a nonprofit promoting and facilitating community conservation actions, is holding webinars on Wednesday, Thursday and Friday covering such topics as nitrates in drinking water, the impact better agricultural practices have on improving water quality and the role nitrate pollution plays in creating the annual “dead zone” in the Gulf of Mexico. All three webinars are free and begin at noon.
The Izaak Walton League also has a Nitrate Watch program, which provides free and easy-to-use kits for people to help assess nitrate levels in streams, rivers, wells and tap water. After nitrate levels are checked using the kits’ test strips, the data can be uploaded to the league’s Clean Water Hub, an online tool that lets the public track the nitrate levels in local water.
As part of the league’s inaugural Nitrate Pollution Awareness Week, anyone reporting data to the Clean Water Hub, as well as watching the webinars and undertaking recommended advocacy actions, will be entered into a raffle to win prizes that include REI gift cards and a countertop reverse osmosis water filtration system.
