The Iowa Department of Natural Resources (DNR) has released a summary of PFAS testing of public water supplies from October 2021 to December 2022. The DNR began sampling public water systems in October 2021 using a tiered system prioritizing locations in close proximity to potential locations of PFAS storage or use and surface water or groundwater sources at higher risk of being contaminated. The 116 drinking water supplies tested represent approximately 46% of Iowa’s population.
Water samples included both treated finished water and raw/untreated water from wells and surface water bodies used for drinking water. Samples were analyzed for 25 PFAS compounds, four of which currently have health advisory levels set by U.S. EPA: PFOA, PFOS, PFBS, and HFPO DA (also known as Gen X Chemicals). Although one or more PFAS compounds were found in 52 finished water samples, just 15 (12%) of the finished water samples reported PFAS concentrations above the current health advisory levels.
If a PFAS chemical with a health advisory is found at a community water supply in either treated or untreated samples, the DNR will revise operation permits to the public water supply. To date, 20 water supply operations permits were revised to require quarterly monitoring.
This summary report was written prior to EPA’s recent announcement of proposed drinking water standards for PFAS chemicals. Once standards become effective, possibly by the end of 2023, water supplies that exceed the standards in finished water will be required to develop and execute treatment plans. In the meantime, many communities have already adjusted their operations to reduce or remove PFAS.
The DNR will continue to sample PFAS in raw and treated water at public water supplies over the next few years. EPA will also require testing of finished water supplies as part of the Unregulated Contaminant Monitoring Rule #5, which includes communities with 3,300 or more people and 18 smaller communities, between 2023-25.
The complete summary and results can be found at iowadnr.gov.