City of Dallas participates in EPA’s data collection for PFAS  

City of Dallas participates in EPA’s data collection for PFAS  

City of Dallas Water Utilities (DWU) is committed to providing superior drinking water services. Our tap water meets all established regulatory requirements for drinking water and our system is rated as a Superior Water System by the Texas Commission on Environmental Quality (TCEQ).   

Direct oversight of water systems is conducted by state drinking water programs implementing the Safe Drinking Water Act. That Act was passed by Congress in 1974 to protect public health by regulating the nation’s public drinking water supply. It authorizes the Environmental Protection Agency (EPA) to set national health-based standards to protect against naturally occurring and man-made contaminants in drinking water. Every five years, EPA is required to identify and monitor for priority contaminants that may be in drinking water but are not yet subject to federal drinking water regulations.  

EPA has the authority to set enforceable maximum contaminant levels (MCLs) for substances in public drinking water systems and has done so for more than ninety contaminants. In Texas, TCEQ oversees public water utilities’ compliance with the national regulations. 

On March 14, 2023, EPA proposed MCLs for the following six types of per- and polyfluoroalkyl substance (PFAS): 

EPA’s Proposed PFAS Regulation 

*A Hazard index is a tool used to evaluate potential health risks from exposure to chemical mixtures. 


PFAS a group of synthetic chemicals used in a wide variety of consumer products and industrial applications since their development in the 1940s. They have unique chemical and physical properties, including oil and water repellence as well as temperature and chemical resistance. PFAS have been, and in some instances continue to be, used in firefighting foam, non-stick metal coating for cookware, paper food packaging, creams and cosmetics, textiles for furniture and outdoor clothing, paints and photography, pesticides, chrome plating, and pharmaceuticals. 

The proposed PFAS MCLs do not require any action until they are finalized, which will occur by September 30, 2024. 

PFAS Monitoring   

EPA uses the Unregulated Contaminant Monitoring Rule (UCMR) to collect data for no more than 30 suspected contaminants in drinking water to support future regulatory determinations, the development of national primary drinking water regulations, and other actions to protect public health.  

The fifth and current monitoring cycle, UCMR 5, requires utilities to monitor for 30 contaminants (29 PFAS compounds and lithium) between 2023 and 2025. PFAS will be monitored at levels between two and twenty ppt. For perspective, one ppt is equivalent to a single drop of water in approximately 20 Olympic-sized swimming pools, or one second in 32,000 years. 

UCMR 5 requires utilities to conduct four quarterly rounds of sampling at each entry point to the water distribution system between 2023 and 2025. For DWU, this means sampling the finished water from each of our three water treatment plants: Eastside, Bachman, and Elm Fork. DWU started monitoring for PFAS under UCMR 5 in March 2023 and the process should conclude in December 2023. 

On August 17, 2023, EPA released to the public the first set of data collected under UCMR 5, including DWU’s results for the first sampling event. The initial data released represents approximately 7% of the total results that EPA expects to receive over the next three years. The table below contains DWU’s results for two PFAS chemicals, PFOA and PFOS. The Hazard Index for the other four PFAS compounds measured through that ratio, was below one (HI < 1) for all three locations. 


DWU Efforts 

In addition to complying with UCMR 5, DWU is also incorporating PFAS monitoring into the source water sampling program; investigating possible PFAS sources to mitigate potential exposure; evaluating established and emerging treatment technologies; and researching near- and long-term strategies to reduce PFAS levels. DWU will continue to comply with all current regulations that apply to its drinking water and will comply with all future regulations as well.  

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