Protecting drinking water quality remains our #1 priority
For over 130 years, the Tampa Water Department has delivered safe, clean water to homes and businesses that meet all federal and state regulatory standards. On June 15, 2022, the Environmental Protection Agency (EPA) issued new health advisory levels to manage the risk for a group of man-made chemicals in drinking water called PFAS (Per- and polyfluoroalkyl substances).
We want to explain EPA’s action and describe the research that the Tampa Water Department has already done, and continues to do, in this area.
Quick facts about PFAS
What are PFAS compounds? PFAS is a large family of compounds that include up to 5,000 chemicals. Since the 1940s, PFAS compounds have been widely used in the manufacturing of carpets, clothing, fabrics for furniture, paper packaging for food, and other materials including Teflon-coated products. They are also used in firefighting foam and in industrial processes. Two prominent PFAS chemical compounds include:
- Perfluorooctanoic acid (PFOA). PFOA has been used to make Teflon and other similar chemicals.
- Perfluorooctane sulfonate (PFOS). PFOS has been used to make stain repellents like Scotchgard™ and fire-fighting foams.
Is PFAS still being used? Over the years, many companies have chosen to voluntarily halt the production and use of certain PFAS chemicals. In fact, most uses of PFOA and PFOS were voluntarily phased out by U.S. manufacturers in the mid-2000s. However, some of these chemicals are still in use for limited purposes.
Why is PFAS a source of concern? PFAS remain present in the environment due to their persistence and the inability to degrade. The EPA confirms that most people are exposed to these chemicals through a variety of consumer products, such as fast-food containers/wrappers, pizza boxes, personal care products, nonstick cookware, stain-resistant coatings used on carpets, and upholstery, and more. Drinking water can be an additional source of exposure in communities where these chemicals have entered the water supplies.
What is the EPA’s Health Advisory Level and what does it mean?
The EPA’s role in establishing drinking water regulations. EPA regulates the safe levels for hundreds of compounds in drinking water. The EPA developed a PFAS Strategic Roadmap in October 2021 to address the health risks and is in the process of setting maximum contaminant levels for PFAS within the scientifically rigorous framework of the Safe Drinking Water Act (SDWA). A proposal is expected in the fall. With science, there’s no such thing as zero, so research is important to determine an acceptable risk level for public health. A health advisory level is commonly the first step in EPA developing a regulation.
Researching PFAS levels in water supplies. Many water utilities, including our scientists at the Tampa Water Department Water Quality Lab, are conducting research to determine the levels of PFAS in our water and how well various treatment options can reduce levels. The EPA is focused on a small number of these compounds that may have health effects at very low concentrations, two of which are PFOAs and PFOS.
How health advisories work. Health advisories are not enforceable like regulations. Instead, the advisories serve as interim guidance before EPA develops a formal regulation and are subject to change as more scientific information is developed.
The health advisory level is the minimum concentration of a compound which may present health risks to an individual over a lifetime of exposure. Because the health effects associated with long-term exposure to a compound may be uncertain, EPA tends to set lower target levels when they issue a health advisory. Sometimes, the advisory is lower than current analytical methods can detect.
The EPA’s new Health Advisory Level for PFAS. The EPA set new Interim Health Advisory Levels at 0.004 parts per trillion for PFOA and 0.02 parts per trillion for PFOS. These are microscopic levels, and trace amounts. For perspective, 1 part per trillion (ppt) is equal to 1 drop in 20 Olympic-size swimming pools.
It’s important to note that these new health advisories are below the reliable detection capability of current scientific equipment. (To put this in context, scientists can currently detect PFAS compounds at 2 parts per trillion.)
Previous PFAS health advisories. The EPA first issued a health advisory level for PFOA and PFOS in 2016 at 70 parts per trillion. This new advisory replaces the 2016 health advisory level.
What are the levels in Tampa’s water?
The Tampa Water Department regularly collects samples of our source raw water (which is primarily the Hillsborough River), as well as the treated finished drinking water once it is in our distribution system. Between June 2018 and October 2019, we collected 17 samples from both our raw water (before treatment) and finished drinking water (after treatment), and tested for several PFAS compounds. The average test result from our raw water was 5.5 parts per trillion for PFOS and 4 parts per trillion for PFOA. The average test result from our finished drinking water was 5.1 parts per trillion for PFOS and 3.7 parts per trillion for PFOA.
What is the Tampa Water Department doing about PFAS?
We recognize the average level of PFAS in our monitoring is above the EPA’s current health advisory levels. That’s why research is a priority. Our scientists need to learn more, specifically:
Determining the levels of PFAS in our water with additional monitoring and identifying any patterns
Understanding established and emerging treatment options
Developing practical and feasible strategies to reduce levels of PFAS as EPA develops and finalizes its future drinking water standards