The Edmonds School District continues investigating the source of forever chemicals found in the stormwater system at Edmonds’ Madrona K-8 School.

The effort came after the Washington State Department of Ecology sent a letter to the district recommending it take action to reduce per-fluoroalkyl and poly-fluoroalkyl substances, or PFAs.

In its Aug. 16 Letter of Concern, Ecology said that perfluorooctanoic acid (PFOA) was found in the Madrona stormwater system at 22 parts per trillion and perfluorooctanesulfonic acid (PFOS) was discovered at about 8 parts per trillion.

No PFAS were reported in the school’s drinking water.

PFAS are a large family of human-made chemicals. They have been used since the 1950s to make a range of stain-resistant, water-resistant, and non-stick consumer products. In Washington state, PFAS exist in certain firefighting foams utilized by the U.S. military, local fire departments and airports. PFAS have been targeted as a public health concern because they do not break down naturally, can travel large distances in water or air, and can build up in the tissues of animals, plants and people.

Joe Scordino, a retired fisheries biologist and member of the newly formed Edmonds Environmental Council, is among local residents who are concerned about the findings.

According to the U.S. Environmental Protection Agency, scientific studies have shown that exposure to some PFAS in the environment may be linked to harmful health effects in humans and animals. Scordino said he and others are worried that those health impacts might not be seen for a generation or two if they get into the water supply.

Madrona K-8 School and its stormwater system were built in 2019, when PFAS were not considered in the 2019 Stormwater Management Manual published by the Department of Ecology. PFAS did not appear until the manual was updated in 2024.

Officials at Olympic View Water and Sewer District raised concerns about the system in 2019, when then-General Manager Lynne Danielson pointed out that the Madrona site sits near the border of the five-year and 10-year areas of influence zones. That means that when a drop of water hits that area, it is expected to take about five to 10 years to reach the water source – in this case, Deer Creek, she explained.

The injection control wells (UIC) used for stormwater detention do not actually involve injection but use the force of gravity. The UIC wells at Madrona filter stormwater through silt, which was common before EPA standards changed in April 2024.

“There are no current guidelines regarding best management practices for PFAS in stormwater, and there are no Washington State maximum contamination levels for stormwater,” said Edmonds School District Communications Director Curtis Campbell.

He added that the UIC is 40 to 50 feet from the aquifer, and the code allows a minimum of 10 feet of separation between its bottom and the aquifer.

Campbell said that Ecology noted during an Aug. 1, 2024, meeting with the school district that school parking lots and fields are not considered as recognized sources of PFAS.

Kelts responded that “Ecology isn’t ready to eliminate any potential sources until we are able to review a PFAS source area assessment.”

Although the PFAS found in the stormwater are not commonly associated with tires, other forms of PFAS are used to make tires. Crumb rubber –  a popular material for playgrounds, outdoor tracks and artificial sports fields—is made from recycled tires.

The parking lot and driveways see heavy use during the school year, and staff use them year-round. There is microscopic rubber rubbed off the tires by the asphalt that then gets washed away into the stormwater system.

While the source of the PFAS hasn’t yet been discovered, “the district takes this matter very seriously and is working with DoE [Department of Ecology] to develop a strategy to move forward to meet their requirements in their Letter of Concern,” Campbell said.

The Olympic View Water and Sewer District serves an area bounded by 200th Street Southwest on the north, 244th Street Southwest on the south, Highway 99 on the east and Puget Sound on the west, which includes the unincorporated Esperance area and the Town of Woodway (see map here). Olympic View sources its water primarily from the South Fork Tolt River Watershed, managed by the City of Seattle Public Utilities (SPU). Olympic View supplements the Tolt supply from its own water treatment plant tied to the spring-fed Deer Creek system in Woodway.

However, concerns have been raised about recent action by the Edmonds City Council to manage stormwater (which generally contains PFAS at various concentration levels) in the city’s two critical aquifer recharge areas (CARAs). The CARAs were established to protect groundwater and public drinking supplies from potential contamination and to ensure adequate groundwater availability. They include the Olympic View-managed drinking water wells located at both Deer Creek and 228th Street Southwest.

As reported earlier in My Edmonds News, the council recently approved an amendment to the city code that would allow shallow underground injection control (UIC) wells, which — according to city staff — would both help protect water quality and control stormwater runoff by diverting runoff into subsurface wells. Some citizens and Olympic View officials fear that the proximity of these proposed wells to the CARAs could result in PFAS contamination of the Deer Creek water that comprises a portion of the drinking water supplied by Olympic View to its customers.

Olympic View Water and Sewer District General Manager Bob Danson said UIC wells at Madrona school bypass an 80-foot thick protective till layer, discharging directly into the sands above the aquifer.

“We are not aware of any testing of the aquifer itself for PFAS at this time,” Danson said. “However, the PFAS-positive stormwater samples, which flow into the sands above the aquifer, present a clear risk of potential contamination to our drinking water source.”

District spokesperson Campbell explained that infrastructure, such as stormwater system components like water injection sites, are only replaced when they are failing, and the five-year-old Madrona system is still working fine.

On Saturday, Oct. 22, 2022, Olympic View took water samples from the UIC wells near the field and the parking lot at Madrona. Edmonds School District claims this sampling was unauthorized, stating that Olympic View “admitted they came onto [Edmonds School District] property” on Jan. 26, 2023.

In response, Danson said that Olympic View staff “only sampled the stormwater in publicly accessible areas on the school property. We reported the findings to the Edmonds School District.”

On Oct. 16, 2023, the school district contracted with Seattle engineering firm Shannon and Wilson to confirm Olympic View’s findings. The school district then discussed the findings with Olympic View in February 2024.

Although the data between Olympic View and Shannon and Wilson varied — with some results showing a 10 parts per trillion difference— both data sets confirmed the presence of the PFAS.

In May 2024, the district met with the Department of Ecology to explain the results of the tests, then met again with Ecology officials in August to discuss the agency’s Letter of Concern.

In its letter, Ecology said that if the district can’t find the source of the PFAS, it should use “additional or alternative” treatment methods that are known to remove PFAS from stormwater.

Keltz said while Ecology has updated its UIC design guidelines in the 2024 stormwater management manuals since the school was built, “the system implemented for filtering pollutants at the Madrona site in 2019 is a viable design option.”

She added that the 2019 and 2024 manuals require an engineer to consider the soil type and other factors in how the water is treated.

Keltz said the primary routes for PFAS entering the stormwater are associated with commercial or industrial processes: landfills, manufacturing facilities, firefighting foam from military bases and airports and application of biosolids.

“Our first priority is source control, meaning keeping PFAS out of the stormwater in the first place,” Keltz said. ”If the school district cannot find the source, then there are some stormwater treatment options that people are starting to see work to address PFAS, such as a filter or soil/compost mixture with granular activated carbon (GAC) or other media that PFAS ‘sticks to.’”

She explained that this option has been effective at removing chemicals, “particularly organic chemicals, from water.” Further, removing PFAS from stormwater is an emerging research area, “so we plan to work with the school district and their consultant on stormwater treatment options.”

“At the consumer/individual level, proper disposal of possible PFAS-containing solid waste materials and minimizing disposal of possible PFAS-containing products to private septic systems would have the most benefit,” Keltz said.

The Washington State Department of Health has consumer information related to PFAS available here.

— By Rick Sinnett