Johnston Municipal Water Supply

Water is essential for your health, and Des Moines Water Works strives to provide Water You Can Trust for Life. Serving approximately 500,000 central Iowans with clean, affordable and abundant drinking water is our primary mission. As your local water provider, our top priority is ensuring reliable, safe water delivery to customers.

To achieve this, we invest responsibly in maintenance and upgrades to critical infrastructure supporting Des Moines and surrounding communities. We continuously monitor water quality to identify and treat contaminants while reviewing our treatment processes for efficiency. Our extensive monitoring program allows us to assess our challenging source waters and treat them effectively.

The Environmental Protection Agency (EPA) establishes regulations limiting contaminant levels in public water systems to ensure safety. This annual report summarizes information about our water sources, detected contaminants, compliance status, and educational information.

Where Your Water Comes From

Des Moines Water Works operates three treatment facilities in central Iowa using a multi-barrier approach including source monitoring, riverbank filtration, and treatment processes of conditioning, filtration, and disinfection, plus distribution system maintenance.

• Saylorville Water Treatment Plant in northern Polk County serves residents north of Des Moines, treating up to 10 million gallons daily from the Des Moines River using ultra-filtration and reverse osmosis.
• L.D. McMullen Treatment Facility at Maffitt Reservoir treats up to 25 million gallons daily from the Raccoon River, serving southwest Des Moines and portions of Warren County, Waukee, Clive, Urbandale and West Des Moines.
• Fleur Drive Treatment Plant serves all other areas, processing up to 75 million gallons daily from the Raccoon River, Des Moines River, or an Infiltration Gallery.

Our chemists and microbiologists test source water daily to determine optimal treatment. They also monitor throughout the treatment process to ensure safety. Once treated, over 1,300 miles of underground mains distribute water to homes and businesses throughout the service area.

Water and Health Information

All drinking water, including bottled water, may reasonably contain small amounts of some contaminants. Their presence doesn't necessarily indicate a health risk. Immunocompromised individuals, cancer patients undergoing chemotherapy, organ transplant recipients, people with HIV/AIDS, some elderly, and infants may be particularly vulnerable to infections and should consult healthcare providers about drinking water.

Nitrate levels above 10 parts per million (ppm) pose health risks to infants under six months, potentially causing blue baby syndrome. Parents of infants should seek advice from healthcare providers if concerned. Des Moines Water Works employs several strategies to maintain treated water below the 10 ppm standard, including source water blending and ion exchange treatment when necessary.

Lead Information

Elevated lead levels can cause serious health problems, especially for pregnant women and young children. Des Moines Water Works minimizes exposure risk through a corrosion control program approved by the Iowa Department of Natural Resources. Lead primarily comes from materials in private service lines and home plumbing. To reduce potential exposure, flush your tap for 30 seconds to 2 minutes before using water for drinking or cooking, especially when water has been sitting for hours.

Cryptosporidium

This microbial pathogen enters watersheds through animal and human waste. Our monitoring shows its presence in source waters. While filtration removes Cryptosporidium, standard filtration cannot guarantee 100% removal. Current testing cannot determine if organisms are viable. Infection symptoms include nausea, diarrhea, and abdominal cramps, with immunocompromised individuals at higher risk of serious illness.

The CDC provides valuable resources on waterborne diseases, prevention strategies, and health implications of various water contaminants. They offer guidance on special populations with increased vulnerability to water quality issues, including young children, pregnant women, the elderly, and those with compromised immune systems. Their recommendations help households make informed decisions about additional water treatment options based on specific health concerns and local water conditions.