Testing for PFAS and Keeping Tacoma's Drinking Water Safe
Update: Nov. 7, 2018
Tacoma’s drinking water remains safe and protected from contaminants, including the group of manmade chemicals labeled PFAS (perfluoridated substances).
PFAS are manufactured for a variety of industrial purposes. If detected in drinking water, PFAS have the potential to raise health concerns.
Recent Test Results at Well 10C
Tacoma Water – in response to national and regional concerns, and as part of its mission to provide clean, reliable water – recently conducted voluntary testing for PFAS at individual wells in its water system. A first test at Well 10C showed PFAS levels that exceeded the EPA Health Advisory Level of 70 parts per trillion; results from a second test at that well were below the EPA Health Advisory Level.
Based on the results of the first test, Tacoma Water notified customers and closed the well for additional testing and maintenance. The closed well served as a source of unfluoridated water. The only people who may have received water with potentially elevated PFAS level were those who went to the well site at 7440 S. Cedar Street in Tacoma and filled their own containers.
Other Test Results
No PFAS were detected in water from the Green River, which serves all Tacoma Water customers with the vast majority of their drinking water. Test results taken 2015, indicated that Tacoma Water customers have only received water with PFAS levels significantly below the federal standard of 70 parts per trillion at their homes and businesses.
Where to Get More Information
For more information about PFAS, including the health and safety risks associated with these compounds, visit the Tacoma-Pierce County Health Department website.
- Is Tacoma Water safe to drink?
Yes. The vast majority of the water you receive from Tacoma Water is filtered water that comes from the Green River, where there was no PFAS detected. The utility also tested the blended groundwater (which comes from multiple seasonal use wells) supplied to Tacoma Water customers, and the PFAS levels are significantly below the EPA Health Advisory Level.
A water sample taken at one well – 10C – showed PFAS levels above 70 parts per trillion, which is the EPA’s Health Advisory Level. A second sample at that same well was below the Health Advisory Level.
Based on the results of the first test, Tacoma Water notified customers and closed the well for additional testing and maintenance.
- How do I know if I drank water from the well that had a high PFAS level?
The only people who may have received water with potentially elevated PFAS level were those who went to the well site at 7440 S. Cedar Street in Tacoma and filled their own containers. The closed well served as a source of unfluoridated water.
- I drank water from the unfluoridated water supply at Well 10C. Should I be concerned?
The EPA Health Advisory Level is based on a lifetime of exposure to two PFAS compounds – PFOA and PFOS – from drinking water. The Tacoma-Pierce County Health Department provides information for people who may be concerned.
- Where can I get unfluoridated water?
While there is no legal requirement to provide unfluoridated water, Tacoma Water provides an alternative location for unfluoridated water at 1614 99th St. E in the Midland area. Testing on that well showed negligible PFAS levels – far below the EPA Health Advisory Level.
- What are PFAS?
According to the EPA, PFAS are manmade chemicals that have been manufactured in the U.S. since the 1940s, and are used in a variety of products, including non-stick, stain-resistant, water-resistant products available on the mass market. They are found in furniture, carpeting, non-stick cookware, outdoor clothing, food packaging and other common household products. Certain types of firefighting foam contain PFAS.
According to the Washington State Department of Health, PFAS exposure is widespread; it is estimated that PFAS may be found in the blood of 98% of the U.S. population. Although toxicity and safety data is still being developed, some of the PFAS compounds have been linked to health problems and environmental impacts.
The Health Advisory Level was set by EPA to provide a margin of protection based upon a lifetime exposure to PFAS compounds.
PFAS have been detected in many drinking water sources around the country. In Washington State, PFAS have been detected in and around the City of Issaquah, Joint Base Lewis-McChord, Naval Air Station Whidbey Island, and Fairchild Air Force Base/City of Airway Heights.
- What prompted Tacoma Water to test its wells for PFAS?
Tacoma Water has followed the national and regional findings of PFAS, and conducted voluntary sampling to understand if PFAS existed in its water system. To ensure safe, reliable drinking water, the utility immediately closed Well 10C after receiving an initial test result that indicated a PFAS level above the EPA Health Advisory Level.
- Why did Tacoma Water wait so long to test its wells?
PFAS detection in drinking water is fairly new science, and PFAS are still unregulated compounds. Tacoma Water first began sampling and testing for PFAS in 2015, with non-detect results for all samples. Scientific improvements now allow for laboratories to detect at much lower levels, and Tacoma Water has begun testing individual well sites, rather than just focusing on locations where groundwater is blended before going to customers.
- What is the source of the PFAS at that well?
Tacoma Water, in cooperation with the State Department of Health, continues to investigate potential sources of the groundwater contamination. Throughout the country, PFAS contamination has been primarily discovered in areas near fire training facilities, military bases, and airports that historically used PFAS-based firefighting foam.