Posted August 3, 2020
Creosote, coal tar have polluted land, Lake Washington sediments
The U.S. Environmental Protection Agency today released its final plan for the cleanup of Quendall Terminals in Renton, a former creosote manufacturing plant and oil storage facility along Lake Washington, where for decades creosote, coal tar, and other hazardous chemicals accumulated on the land, in groundwater, and in lake sediments.
EPA divided the site into two “operable units”: OU-1 for the upland portion of the site and OU-2 for the lakebed portion just offshore. The agency estimates that cleanup of OU-1 will cost approximately $66 million and OU-2 will cost $40 million. Both estimates include the cost of monitoring the effectiveness of the remedy for 100 years.
The Quendall Terminals site was placed on the Administrator’s Emphasis List of Superfund sites slated for “immediate, intense attention” by the Administrator and leadership in December 2017 due to the site’s exceptional potential for expedited cleanup and redevelopment.
“We’re excited to move forward on this long overdue cleanup,” said Chris Hladick, EPA’s Regional Administrator for Region 10. “Sitting along the Lake Washington shore, Quendall is a potential gem, and thus one of the many places across the country where the Superfund Task Force’s work has made a significant difference.”
“Over the last three years we’ve been able to focus on Quendall to both speed the cleanup and maximize the area available for redevelopment,” continued Hladick. “This is a great day.”
In finalizing the cleanup plan, the EPA reviewed comments received during a 60-day comment period after the agency released its proposed plan in September 2019. Based on some of the comments received, the agency made minor changes to the approach for OU-1, yet the plan still calls for the same three components:
- In-place underground smoldering combustion of areas with very high concentrations of creosote and coal tar and collection of combustion by-products.
- Cement encasement – called in-situ solidification, or ISS – of soil contaminated with lower concentrations.
- A cap of about three feet of clean soil over areas where contamination levels are very low.
The EPA will deal with the contamination in the lakebed sediments of OU-2 by:
- Dredging and disposing offsite sediment containing high levels of creosote and coal tars.
- Capping areas with upwelling of contaminated groundwater.
- Enhanced natural recovery, which includes adding clean sand to speed up the cleanup in natural recovery areas.
Past releases of coal tars and creosote at the former creosote manufacturing facility – which operated from 1917 to 1969 – contaminated about 22 acres of soil and groundwater and about 29 acres of lake sediments. Neither the groundwater nor Lake Washington are used as a drinking water source, so the site does not pose a risk to the City of Renton’s water supply.
Quendall Terminals acquired the property in 1971. Between 1969 and 1983 the site was used to store diesel, crude and waste oils. From 1975 to 2009 the site was used primarily for log sorting and storage. The site is currently vacant and fenced.
In 1999, the Washington Department of Ecology Toxics Cleanup Program began to address the contamination at the site under the state’s toxics cleanup law, and in May of 2005, Ecology requested that EPA take the lead for overseeing the cleanup.
In 2006, EPA requested that two of the site’s potentially responsible parties – Altino Properties and J. H. Baxter & Company – conduct a remedial investigation and feasibility study to better understand the type, amount of, and risks posed by the contamination and develop a cleanup plan. The companies completed the remedial investigation in 2012 and the feasibility study in 2017.
For a copy of the Record of Decision go to www.epa.gov/superfund/quendall-terminals and then click on “Site Documents and Data.”