Treating drinking water in Iowa City is a multi-step process that draws untreated water from various sources and pumps out clean, safe, potable water to customers for drinking and general use. The Iowa City Water Division publishes an annual Consumer Confidence Report as required by the Safe Drinking Water Act. Information specifically related to the Lead and Copper Sampling Program is available, as well as links to information provided through the EPA. Along with mandatory sampling and reporting requirements, the Iowa City Water Division participates in other contaminant monitoring and testing programs.

Water treatment

The Iowa City water treatment plant draws water from various raw water sources.  These sources include a deep Jordan well (approximately 1,600 feet deep), deep Silurian wells (approximately 400 feet deep), shallow alluvial wells (approximately 40 feet deep), the Iowa River, and a manmade lake. By blending water from these many sources, Iowa City has the ability to provide an abundant amount of excellent, high quality water.

The water purification facility operates a lime softening coagulation-sedimentation, granular activated carbon filtration process. Starting with source water that is virtually free of sediment, the lime softening process can reduce calcium hardness in water by two-thirds. The process also removes organics that impart undesirable tastes, odors, and colors to water.

The granular activated carbon filters polish the water by removing microscopic contaminants, thereby further reducing offending tastes and odors. Chlorine is added to ensure water in the water distribution system remains potable and safe for consumption. Fluoride is added at an optimized level to enhance the source water’s natural fluoride content, which improves bone and tooth strength in younger children as well as adults.

Watch a video about the water plant's purification process.

We provide customers with a water quality that exceeds all quality standards required by the Environmental Protection Agency. More than 200 tests a day are performed by state licensed water treatment plant operators to ensure water delivered to our customers exceeds State and Federal drinking water standards. In addition to these tests, additional tests are performed by the University of Iowa State Hygienic Laboratory to ensure the water reaching customers’ homes is safe to drink. A safe, dependable water distribution system is maintained by state certified Water Distribution Maintenance Operators and a water main repair/replacement budget.

Consumer Confidence Reports

To meet Safe Drinking Water Act mandates for consumer notification, all community water supplies like Iowa City are required to publish an annual Consumer Confidence Report. These reports include information and about various water quality parameters and testing results. For customers needing information for a specific parameter not covered in the Consumer Confidence Report, additional information may be requested by contacting the Water Division at 319-356-5160.

Lead and copper in drinking water

The Safe Drinking Water Act (SDWA) requires all community water suppliers, including the Iowa City Water Division, to participate in a Lead and Copper Sampling Program. Since 1992, the Water Division has routinely sampled for lead and copper in designated locations throughout the drinking water system.

National news reports from the recent past have covered the link between elevated lead levels in children living in Flint, Michigan, with lead contamination of the Flint drinking water system. A change in their raw water source made in 2014 caused a shift in the chemical stability of the finished drinking water. Flint’s drinking water became corrosive to metals, including lead, and resulted in high levels of lead leaching from lead pipes and solder into their tap water. In Iowa City, operators at the Water Division measure and calculate water stability factors daily and make process adjustments based on this data to assure that the water which enters the drinking water system is stable and non-corrosive.

The EPA has set the action level for lead concentration in drinking water at 0.015 mg/L (15 parts per billion) in the 90th percentile of samples. Iowa City water has remained in compliance with this rule. In 2014, the 90th percentile lead concentration was 0.004 mg/L (4 parts per billion), well below the EPA action level. Due to different residential plumbing materials being used in homes over the years, it is possible that lead levels in some homes may be higher than others in the community. 

Infants, children, and pregnant women are typically more vulnerable to lead in drinking water than the general population. If you are concerned about elevated lead levels in your home, you may flush your tap for 30 seconds to two minutes prior to using water to purge your service line. You may also have your water tested. For additional information, contact the Iowa City Water Division at 319-356-5165, the Safe Drinking Water Hotline at 800-426-4791, or visit the Environmental Protection Agency website at

Current Iowa City Water Division contaminant monitoring and testing programs

Iowa City participates in EPA program to monitor for unregulated drinking water contaminants

Every five years, the U.S. Environmental Protection Agency is required to issue a new list of up to 30 unregulated contaminants that must be monitored in public water systems. This requirement is mandated under 1996 amendments to the Safe Drinking Water Act. The Unregulated Contaminant Monitoring Rule (UCMR) provides baseline data that the EPA may combine with toxicological research to make decisions about potential future drinking water regulations. There are no current health standards set for UCMR contaminants. For more detailed information on UCMR, visit

The benefits to the environment and public health due to the UCMR program are:

EPA and other interested parties will have scientific data on targeted contaminants in drinking water;
EPA can assess the impact of new regulations on public health; and
EPA can provide exposure level estimates.

The EPA, state governments, laboratories, and public water systems participate at various stages and levels of the program. The Iowa City Water Division participated in the third round of contaminant testing between 2013 and 2015 by monitoring for 28 chemicals and two viruses. This data set is one of the primary sources of information the EPA uses to make regulatory decisions regarding exposure to contaminants that may be of concern to public health. 

The Iowa City data summary for unregulated contaminant monitoring was completed in July 2016.  The table is listed by contaminant name, and indicates the minimum reporting level, or MRL, associated with each contaminant. Any sample result that fell below the MRL was reported as “less than the MRL,” or “<MRL,” to the EPA. Of the 28 contaminants listed, only five had reported concentrations greater than the MRL in Iowa City: chromium, chromium-6, molybdenum, strontium, and vanadium. The EPA’s determination on unregulated contaminants for the third round are available at

To learn more about a particular contaminant and its potential regulatory status, visit the EPA’s Contaminant Candidate List and Regulatory Determination webpage at