EPA updates cleanup plan for Wyckoff-Eagle Harbor Superfund Site on Bainbridge Island
Next cleanup phase will tackle creosote contamination at the former Wyckoff wood treating facility
SEATTLE The U.S. Environmental Protection Agency has updated and revised cleanup plans for the Wyckoff-Eagle Harbor Superfund Site, on Bainbridge Island, Washington. The newly selected cleanup technology will permanently contain and immobilize creosote and other contaminants in soil and groundwater under the former Wyckoff wood treating facility. This work will protect the island’s drinking water aquifers and prevent contaminants from reaching Puget Sound.
“Cleaning up historic contamination at the Wyckoff site is critical to protecting people’s health and the health of Puget Sound,” said EPA Region 10 Administrator Chris Hladick. “We have improved our cleanup plans in response to public comments, and we look forward to making the property and nearby beaches safe again for the community to use and enjoy.”
EPA’s May 2019 Record of Decision Amendment and (https://semspub.epa.gov/work/10/100151846.pdf) fact sheet describes the cleanup actions, which include:
- Installing an underground cutoff wall along the south side of the former wood treating area to divert clean groundwater away from contaminated soil and groundwater.
- Treating at least 267,000 cubic yards of contaminated soil and groundwater by mixing in a cement slurry to permanently immobilize the contamination on site.
- Covering the soil treatment area with a clean soil cap and building a new stormwater drain.
There are significant benefits expected from this updated cleanup plan. Once construction of the final protective soil cap is complete and long-term monitoring is underway, the property will be safe for people to visit and play. Bainbridge Island Metro Parks plans to add this cleaned-up property to Pritchard Park, a popular community recreation area. By solidifying the soil and groundwater contamination in a concrete-like matrix, the cleanup will better protect the public beaches, Eagle Harbor and Puget Sound. This work will lead to a decrease in contaminant levels and enable the state to stop active groundwater extraction and treatment operations. Ending groundwater treatment operation will save Washington state taxpayers at least $750,000 in annual operations costs.
This updated cleanup plan modifies an earlier cleanup decision for the site, issued in 2000. That cleanup plan called for steam-enhanced extraction of contaminants from the soils and groundwater. Pilot testing showed that steam-enhanced extraction could not meet project cleanup goals. As a contingent remedy, EPA installed a steel sheet pile wall around three sides of the site and operated a continuous groundwater extraction and treatment system to contain the contamination. While this containment system has prevented large-scale releases of contaminants to Eagle Harbor, it is expensive to operate, and has not entirely stopped contaminants moving into Eagle Harbor or the groundwater aquifer.
In 2016, EPA proposed a cleanup plan for the nearshore, beach and upland areas to remove and contain the contamination and treat contaminated groundwater. This work was later divided into two phases to expedite the priority cleanup of the beaches and replacement of the containment. Phase one, described in the (https://semspub.epa.gov/src/document/10/100093658) May 2018 Record of Decision Amendment, will improve the site access road, replace the aging steel sheet pile perimeter wall, and dredge and cap contaminated beach sediments. The first phase is expected to cost an estimated $36 million. Phase two is expected to cost an estimated $60 million. Construction of both phases is scheduled to be completed by 2032.
Creosote Health Risks
Creosote is a chemical used to treat and protect utility poles, pier pilings and wooden rail road ties. At the Wyckoff site, creosote remains in the beach sediments north and east of the former wood treating site. Seeps of creosote are especially prevalent during low tides in the summer. The creosote appears as a brown oil that releases a rainbow sheen. Creosote contains polycyclic aromatic hydrocarbons or PAHs which can cause cancer. Creosote can also cause chemical burns on bare skin. EPA advises all Pritchard Park visitors and their pets to avoid the closed areas of the beach until the cleanup is completed. Off-limits areas are marked with warning signs and can be viewed in EPA’s (https://semspub.epa.gov/src/document/10/100096339) Wyckoff Beach Safety Fact Sheet.
The updated cleanup plan and more information is available on EPA’s Wyckoff Superfund website: Wyckoff-Eagle Harbor Superfund Site