Water quality

The Iowa City Water Division's mission to provide clean safe water is clear, our commitment to great customer service is clearly understood and delivered, and our product is clean, clear and safe.  We provide customers with a water quality that exceeds all of the quality standards required by the Environmental Protection Agency. More than 200 tests a day are performed by licensed water treatment plant operators. In addition to these tests, others are performed by University Hygienic Laboratory to ensure that the water reaching your home is safe to drink.

2016 Consumer Confidence Report

Water treatment

The water purification facility is utilizing 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 the water by two-thirds. The process also removes organic that harbor taste, odor and color.

The carbon filters polish the water by removing contaminants, and eliminating tastes and odors. Chlorine is added to ensure disinfection in the water distribution system. Fluoride is added at an optimal level to enhance the source waters natural fluoride content which improves bone and tooth strength in younger children as well as adults.

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” (UCMR3) provides baseline data that the EPA may combine with toxicological research to make decisions about potential future drinking water regulations. There are no health standards set for UCMR contaminants at this time.

The EPA, state governments, laboratories and public water systems participated at various stages and levels of the program. The Iowa City Water Division participated in the third round of contaminant testing in 2013-15 by monitoring for 28 chemicals and two viruses.

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.

This data set is one of the primary sources of information the agency uses to make regulatory decisions regarding exposure to contaminants that may be of concern to public health. 

The EPA’s determination on unregulated contaminants will likely be announced in January 2017 at: https://www.epa.gov/ccl/contaminant-candidate-list-4-ccl-4-0.

Iowa City UCMR data summary for chemical contaminants, July 2016

The table is available here and contains the results for unregulated contaminant monitoring by Iowa City as part of the EPA’s UCMR3. The contaminant name is listed in the first column. The second column contains the EPA’s minimum reporting level (MRL). Any sample result that falls below the MRL is simply reported as “<MRL” (less than the MRL) by the EPA. Of the 28 contaminants listed below, only five had reported concentrations greater than the MRL: chromium, chromium-6, molybdenum, strontium, and vanadium.

For more detailed information on UCMR 3, visit www.epa.gov/dwucmr/third-unregulated-contaminant-monitoring-rule.

To learn more about a particular contaminant and its potential regulatory status, visit the EPA’s Contaminant Candidate List and Regulatory Determination webpages at: www.epa.gov/ccl/contaminant-candidate-list-3-ccl-3.

Iowa City’s mission is to provide clean, clear, safe water to our customers. If you have questions or concerns about unregulated drinking water contaminants, contact Craig Meacham, Water Operations, at 319-356-5165.


Lead testing of drinking water

National news reports have covered the link between elevated lead levels in children living in Flint, Michigan with lead contamination of the drinking water system there. A change in the raw water source made in 2014 caused a shift in the stability of the drinking water. Flint’s drinking water became corrosive and resulted in high lead levels in 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 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. The action level of 0.015 mg/L (15 parts per billion) lead concentration in the 90th percentile of samples is required. Iowa City water has remained in compliance with this rule. In 2014, the most recent sampling session, 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, 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. 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 EPA website at www.epa.gov/safewater/lead.