Each year, Arlington Water Utilities laboratory staff tests the city’s water before, during, and after the water treatment process to make sure Arlington tap water meets all safety and health guidelines. The U.S. Environmental Protection Agency sets these guidelines as part of its authority under the federal Safe Drinking Water Act. Each year, test results are reported to the Texas Commission on Environmental Quality (TCEQ) and published in the department’s Consumer Confidence Report, which is available here: ArlingtonTX.gov/waterccr. The list of regulated chemicals from the EPA and TCEQ, called the National Primary Drinking Water Standards, evolves over time as rigorous scientific examinations reveal new concerns.

 As part of that process, the US EPA released a proposal on March 14, 2023 for the first National Primary Drinking Water standards for six per- and polyfluoroalkyl substances, also known as PFAS. PFAS substances have been used since the 1940s in industry and consumer products like nonstick cookware and firefighting foam, according to the EPA. Because these substances break down slowly and can build up in the environment over time they have gained the nickname “forever chemicals”, PFAS compounds have been found in water, air, and soil.

Humans can ingest PFAS through a variety of foods, drinking water, or even through inhaling contaminated dust particles. Exposure to PFAS substances has been shown to have harmful effects on humans, especially when exposure is over long periods of time or during pregnancy or breastfeeding. Some of the health effects linked to these compounds by the EPA include cancers, heart attacks, strokes, and developmental (birth weight) problems.

The EPA has not had regulations in the past for the six PFAS chemicals in the March 14 announcement. However, some PFAS substances were included in a previous round of testing conducted and reported under the EPA’s Unregulated Contaminants Monitoring Rule. That rule, which is referred to as the UCMR, requires public water systems around the country to periodically test for unregulated compounds and report any occurrences. Each round of nationwide UCMR testing is referred to by a number, such as UCMR1, UCMR2, etc. The UCMR process, along with information about the health and economic risks posed to the public, helps the EPA and TCEQ make decisions about which contaminants to add to the regulated list. When setting regulatory limits, the EPA also considers the ability of analytical chemistry techniques to test for a substance and the treatment technology available to remove the substance from raw or untreated water.

In 2014, Arlington Water Utilities tested for six PFAS substances that were part of the UCMR3 round of testing. No detections of the PFAS chemicals were made in Arlington. The analytical methods used at the time would have reflected as little as 50 parts per trillion of the substances in Arlington’s tap water. (One part per trillion is about a drop of water in 20 Olympic-sized pools.) Though the new rules proposed in March 2023 won’t take effect until later this year, Arlington Water Utilities and other utilities throughout Texas are already making plans to test for PFAS compounds as part of a fresh round of Unregulated Contaminants Monitoring Rule, called UCMR5.

Arlington will begin UCMR5 testing of PFAS compounds in June 2023. Results from the first round of UCMR testing will be reported to the EPA a few months later. In this round of testing, the detection levels possible with newer analytical methods used will be much lower – at 4 ppt for most PFAS on the list.

If the EPA’s new PFAS rules are enacted as proposed later this year, Arlington would initially be required to test for the six PFAS substances four times a year and report any violations of the EPA’s PFAS Maximum Contaminant Level to the public within 30 days. Testing could be required less frequently if Arlington’s results were consistently well under the maximum level.

As it does with all regulated contaminants, Arlington Water Utilities will use information from future PFAS testing to determine whether changes to the City’s water treatment processes are needed to protect public health.

Listed below are the six PFAS chemicals as well as the Maximum Contaminant Level (MCL) and the Maximum Contaminant Level Goal (MCLG) proposed. An MCLG is the level of a contaminant in drinking water below which there is no known or expected risk to health. An MCL is the highest level of a contaminant that is allowed in drinking water. MCLs are set as close to the MCLGs as feasible using the best available treatment technology. A health index is an equation reached by combining information from measurements of the four remaining chemicals.