Department of Ecology News Release - October 25, 2017

Long-term environmental plan proposed for part of South Park Landfill site
Public can review and comment through Dec. 13; informational meeting Nov. 28

SEATTLE – The public has an opportunity to review and comment on a proposed environmental cleanup plan and legal agreement for the closed South Park Landfill in South Seattle. The maintenance and monitoring plan would establish long-term protections for public health and the environment.

The Washington Department of Ecology seeks public comment through Dec. 13, 2017 – and will host an informational meeting on Nov. 28, 2017 – on the plan for 30 acres of the 40-acre landfill. People also can comment on an updated public participation plan and earlier studies. The studies evaluated environmental conditions for the entire site and cleanup options for the 30 acres.

The city of Seattle operated the landfill from the 1930s to 1966 when the city opened a transfer station on part of the property.

Contaminants of potential concern in soil at the site include arsenic, lead, diesel, and oil. Environmental studies performed at the site have detected groundwater contamination from arsenic, iron, manganese, vinyl chloride, and possibly dichloroethene and benzene.  Landfill gas – mostly methane and carbon dioxide – also is present at the site but is not getting into nearby buildings.

The site originally belonged to King County, but now has several owners. Two of them have received Ecology approval to perform interim cleanups on their respective properties, which prepare their parts of the former landfill for long-term maintenance and monitoring. South Park Property Development LLC (SPPD) completed a 19-acre interim cleanup in 2015, and the city is preparing to begin cleanup work on its 11 acres.

Both projects are designed to isolate the landfill waste from human contact, keep stormwater out of the landfill with pavement or buildings, and to build systems that keep landfill gases out of buildings on or near the site. These are typical cleanup requirements for closed municipal waste landfills.

Ecology proposes long-term plans and a legal agreement with the city and SPPD, plus King County. The agreements would settle their legal liabilities for their portions of the landfill. The plans would require monitoring; five-year inspections; programs to maintain the gas controls and landfill covers; restrictions on future use of the properties; and contingency plans in case of future gas or groundwater problems.

Ecology will address cleanup of the site’s remaining 10 acres separately.

Review documents

Submit comments and questions

Attend a public meeting

Ecology will present information about the site’s cleanup process and answer questions:

Cleanup of the South Park Landfill site, located about 1,500 feet from the Lower Duwamish Waterway (LDW), contributes to a larger effort to control sources of contamination to the waterway.  Ecology and the U.S. Environmental Protection Agency jointly oversee the LDW cleanup, which includes approximately five miles of the waterway upstream from Harbor Island.

Contact:

Larry Altose, communications, 425-649-7009, @EcySeattle

Jerome Cruz, site manager, 425-649-7094