July 30, 2025 CIWW Update
The CIWW Technical Committee voted yesterday to phase in commercial lawn watering beginning today! This lawn watering will be requested on the same even/odd voluntary lawn watering schedule as residential lawn watering.
Even numbered addresses, Sunday, Wednesday, Friday
Odd numbered addresses, Tuesday, Thursday, Saturday
No watering on Monday
July 21, 2025 CIWW Update
Due to the heavy rainfall we have received, the nitrate concentrations have dipped below 10 mg/L in both rivers and remain below 10 mg/L in the Infiltration Gallery.
Residential lawn watering begins July 22!
Even numbered addresses – Sunday, Wednesday, Friday
Odd numbered addresses – Tuesday, Thursday, Saturday
No watering on Monday
The first phase consists of residential lawn watering.
The second phase is commercial lawn watering – this includes businesses such as gas stations, business complexes, banks, malls, etc.
The third phase includes local governments including city, county, state, and school districts.
Stage III Update
All water produced by Central Iowa Water Works continues to meet all safe drinking water standards.
We continue to see the nitrate levels remain stubbornly high on both the Raccoon and Des Moines Rivers but the concentrations in the gallery are decreasing.
How does the nitrate removal facility work?
The Fleur Nitrate Removal Facility uses a process called ion exchange. Fleur’s facility involves eight ion exchange vessels each rated for 1,000 gallons per minute or 1.4 million gallons per day. Each vessel is filled with a special media, called resin. In Fleur’s process, we saturate that resin with a salt (NaCl) solution. Then as the water with nitrate passes through the resin it exchanges the nitrate (NO3-) ion for a chloride (Cl-) ion. The nitrate ion stays trapped in the resin. Over time the number of available chloride is reduced, thus reducing the system’s ability to remove more nitrate. That is when the vessel must be regenerated. To regenerate, the trapped nitrate is flushed out and the resin is resaturated with sodium chloride, thereby returning its ability to remove nitrate. The flushed-out nitrate and chloride is then wasted to the Des Moines Metropolitan Wastewater Reclamation Authority (WRA). The treated water coming out of the nitrate removal facility is typically less than 1 mg/L Nitrate-N. Because the nitrate removal facility has a limited treatment capacity, not all water that is treated in the plant passes through the nitrate removal facility. This low nitrate water is then blended back into the plant flow to ensure the overall nitrate concentration meets or exceeds the standard. When
But what does the WRA do with the waste stream? – You can find the answer here: https://www.kcci.com/article/what-happens-to-nitrates-after-they-are-removed-from-drinking-water-in-central-iowa/65179925
Stage III Updates
See CIWW update here for July 7, 2025
June 27, 2025 Water Shortage
Please see today’s update from Central Iowa Water Works below. Also, there have been some questions today about boiling of water. We want to ensure folks have the correct information.
Boiling water questions and daily water quality update from Central Iowa Water Works.
