EPA proposes plans for Quendall Terminals cleanup

As part of the work of the EPA Administrator’s Superfund Task Force, in December of 2017 the EPA placed Quendall Terminals on its list of Superfund sites slated for ‘immediate, intense attention’ from EPA leadership due to their potential for expedited cleanup and redevelopment. The other Region 10 site on the ‘Administrator’s Emphasis List’ is the Portland Harbor site in Oregon.

“We’re excited that the beginning of the cleanup of Quendall Terminals is in sight,” said Chris Hladick, EPA’s Regional Administrator for Region 10. “Being right on Lake Washington, 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. The extra attention we’ve been able to focus on Quendall has improved the Proposed Plans we’re releasing today, so we’re optimistic that these plans will both speed the cleanup and maximise the area available for development.”

EPA has divided the Quendall site into two “operable units: OU1 for the upland portion of the site and OU2 for the lakebed portion just offshore.

EPA’s proposed plan for the upland area takes a phased approach for dealing with the pollution including:

• Thermal oxidation (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 (ISS) – of polluted soil with lower concentrations.
• A cap of about three feet of clean soil over areas where pollution levels are very low.

The EPA also proposes three approaches to the pollution in the lakebed sediments:

• Dredging and offsite disposal of sediment containing creosote and coal tars.
• Capping of areas with upwelling of pollution from groundwater.
• Enhanced natural recovery, which includes the addition of sand to speed cleanup in areas where natural recovery is the best approach.

Past releases of coal tars and creosote at the former creosote manufacturing facility, which operated from 1917 - 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 - 1983, the site was used to store diesel, crude and waste oils. From 1975 - 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 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 and amount of contamination and develop a cleanup plan. The companies completed the remedial investigation in 2012, and the feasibility study in 2017. EPA has also conducted supplemental studies at the site.

The EPA will take public comments on the proposed plans 9 September through 9 October.

Read the article online at: https://www.worldcoal.com/coal/13092019/epa-proposes-plans-for-quendall-terminals-cleanup/