Per- and Polyfluoroalkyl Substances (PFAS)
Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic chemicals used in a wide range of consumer products and industrial applications, including non-stick cookware, water-repellent clothing, stain-resistant fabrics and carpets, cosmetics, firefighting foams and products that resist grease, water and oil. Because they break down very slowly in the environment, PFAS are sometimes called "forever chemicals."
In December 2024, Austin Water released results from water quality testing completed in 2023–2024 under the EPA's Fifth Unregulated Contaminant Monitoring Rule (UCMR 5). The rule required drinking water providers to test for lithium and 29 specific PFAS chemicals, six of which will soon be regulated. Austin Water's results revealed little to no detectable traces of PFAS in Austin's drinking water. Because PFAS levels were either not detected or were lower than EPA regulatory limits, no additional treatment is required at this time.
Upcoming PFAS Regulations
- 2023–2027 — Water utilities nationwide participated in UCMR 5 testing. Results will be used to determine future testing and treatment requirements.
- 2027–2029 — Rules for PFAS sampling and reporting will take effect.
- 2029 and beyond — Required treatment processes to remove PFAS from drinking water must be in place.
UCMR 5 Test Results
Testing was completed in 2023–2024. UCMR 5 results are shown in parts per trillion (ppt). For reference, one ppt is equivalent to one drop in three Barton Springs Pools, 1.2 square inches in the total city limits of Austin (roughly 305 square miles), or one cent in $10 billion. Because testing involves these trace amounts, some variation between quarters can be expected.
Some PFAS will be regulated using a Hazard Index computed from a mixture of four distinct PFAS. Austin's Hazard Index ranges from 0.0 to 0.6 with an average of 0.2 across all four quarters.
UCMR 5 Results — Substances Detected (2023–2024)
| Substance | Highest Level Allowed | Austin Average | Q1 | Q2 | Q3 | Q4 |
|---|---|---|---|---|---|---|
| PFOA* | 4.0 ppt | 0 | 0 | 0 | 0 | 0 |
| PFOS* | 4.0 ppt | 0.79 | 0 | 0–4.8 | 0 | 0 |
| PFNA* | 10 ppt | 0 | 0 | 0 | 0 | 0 |
| HFPO-DA (GenX)* | 10 ppt | 0 | 0 | 0 | 0 | 0 |
| PFHxS* | 10 ppt | 2.3 | 0 | 0–6.2 | 0–4.8 | 0–4.0 |
| PFBS* | Not regulated individually | 1.4 | 0 | 0–5.1 | 0–3.6 | 0 |
| PFBA | Not regulated | 2.3 | 5.7–8.4 | 0 | 0 | 0–5.5 |
| PFHxA | Not regulated | 0.5 | 0 | 0–3.3 | 0 | 0 |
| PFPeA | Not regulated | 1.2 | 0 | 0–4.1 | 0–3.1 | 0 |
| 21 Other Compounds | Not regulated | 0 | 0 | 0 | 0 | 0 |
*Indicates chemicals to be regulated in 2027. For more information, see the EPA's proposed limits table.
Samples were collected for lithium and a total of 29 PFAS chemicals in 2023–2024. This table contains results for the substances detected during that monitoring period. Unregulated contaminants are those for which EPA has not established drinking water standards. The purpose of unregulated contaminant monitoring is to assist EPA in determining whether future regulation is warranted. For additional information, visit epa.gov/ucmr or call the Safe Drinking Water Hotline at 800-426-4791.
More Information
- Water Quality Reports — annual Consumer Confidence Reports and water quality data
- Monthly and quarterly water quality summaries — current results including hardness, pH, total dissolved solids and more
- EPA PFAS information
Contact Austin Water's Water Quality Manager at 512-972-0012 with questions about PFAS or water quality testing.