City signs off on dump cleanup

After more than 40 years of prodding and mandating by Mason County and the state, the City of Shelton signed off on the final cleanup of the toxic C Street landfill.

The Shelton City Council on Tuesday evening voted unanimously to close out the contract on the construction part of the cleanup of the 17-acre landfill west of downtown Shelton and U.S. Highway 101, which was completed in June.

"Staff does not expect any additional action on the city's part pertaining to this project and can be closed out," the city's report states.

That doesn't mean the city's involvement in the project is over. The land will be surveyed next year, and the water in the eight wells monitored for five years.

The city paid almost $2.6 million to the cleanup contractor, Brumfield Construction. The state Department of Ecology paid about $2.1 million of that cost.

"That was a very, very long project," said Mayor Eric Onikso.

Private owners mined the site for sand and gravel before the city bought the land in 1928 to use as a municipal landfill.

The former Rayonier pulp mill and research laboratory dumped byproducts and demolition debris at the landfill. The city dumped sludge from its wastewater treatment sites. From 1976 to 1981, wastewater treatment sludge containing ash from Simpson Lumber Co.'s Shelton mill was dumped at the site.

When the Shelton Hardware Store burned to the ground, all the fixtures, chemicals and pesticides were trucked to the site and dumped. Trash was burned in the open air and in an incinerator.

In a December 1981 letter to the mayor and city commissioners, then-Mason County Health Officer John Butler said the city had been observed dumping sludge from its treatment plant at the C Street dump, despite it not being a permitted solid-waste disposal site. The city was depositing about 120,000 gallons of sludge per month, creating a 4-foot-deep pond accessible to people and animals, the letter stated.

In the letter, the county ordered the city to stop disposing the sludge at the site, and to establish a schedule "for submitting a plan and timetable for the Health Department for fencing or otherwise limiting access to the sludge already deposited at the Old City Dump."

In 1986, an inspector from the state Department of Ecology noted the City of Shelton had not yet closed the landfill and cited evidence of newly dumped sludge and household waste. Citing that report, Mason County instructed the city to close the dump in compliance with state laws and monitor the groundwater. The state Department of Ecology also ordered the city to close the landfill under the State Model Toxics Control Act.

In January 2015, the department named the city the potentially liable party responsible for cleaning up the site. In October of that year, the then-Shelton City Commission gave preliminary approval to a plan to identify toxins and begin a cleanup strategy at the landfill. The commission passed an Agreed Order with DOE that made the city responsible for completing a technical memorandum identifying "chemicals of concern" and screening levels at the site; developing a remedial investigation plan; conducting a feasibility study; and defining the cleanup action plan.

In 2016, the city entered into an agreement with Ecology to perform a remedial investigation and feasibility study and to submit a draft cleanup action plan for the site. The remedial investigation field work was conducted from 2017 to 2020, and the final plan submitted to Ecology in 2021. The cleanup construction was performed between January and June this year.

A 2-foot layer of native sand and gravel was placed on top of the landfill waste. A 6-inch layer of vegetative topsoil was placed on top of that. The surface of the land was hydroseeded. Finally, a 6-foot-tall chain-link fence was installed around the perimeter of the soil cap.