Colville Post & Poles

Ecology is conducting additional site characterization to help us develop the final cleanup plan. Soil sampling was completed in September 2025, and groundwater analysis and sampling will be conducted from late 2025 through fall 2026. This information will supplement what is in the remedial investigation and feasibility study that was completed in 2021.

We are working on getting funding to complete the full cleanup. Our next step is to draft the cleanup action plan, which will be available for public comment before becoming final. The plan will propose a final cleanup for contaminated soil and groundwater.

The nearly 23-acre site is located at 396 Highway 395 North, four miles outside of Colville in Stevens County, Washington. The site is within 200 feet of the Colville River, which flows into Lake Roosevelt, a reservoir created by the Grand Coulee Dam on the Columbia River.

Colville Post & Poles, Inc., and several previous owners treated wood, primarily fence posts and rails, for about 60 years (1940s–2005) at this location. Raw wood was dipped in tanks of heated solution and then dried on nearby drip pads. Treated wood was stockpiled on the ground in various locations in the yard. 

Throughout the wood-treating period, pentachlorophenol and diesel leaked from piping and drip pads. In 1989, a 10,000-gallon above-ground storage tank leaked pentachlorophenol to the ground.

In 2000, the Confederated Tribes of the Colville Reservation petitioned the U.S. Environmental Protection Agency (EPA) to assess contamination at the site. Colville Post & Poles, Inc., closed down in 2005 when the owners couldn’t afford upgrades required to protect human health and the environment.

Cleanup at the Colville Post & Poles site is government-funded because the site owners/former operators are unable pay for it. The EPA and Ecology have taken interim cleanup actions (see details below) to protect human health and the environment while a final cleanup plan is developed. The public was invited to review and comment on the interim cleanup actions.

Ecology made the draft remedial investigation/feasibility study work plan and addendum available for public comment July 4 to September 2, 2016. We responded to comments from two parties and made some changes to the remedial investigation/feasibility study work plan following the comment period.

Ecology investigated the extent and locations of remaining contamination at the site and held a public comment period for the draft remedial investigation/feasibility study that assesses cleanup options November 29 to December 30, 2021. We responded to comments from one person and the Stevens County Commissioners. 

EPA interim cleanup actions

In 2005 and 2006, the EPA investigated the site, demolished treatment and storage buildings, installed groundwater monitoring wells, and excavated and safely disposed of some contaminated soil, debris, and drummed wastes.

Ecology interim cleanup actions

When Eastern Washington Clean Sites Initiative funding became available in 2015, Ecology removed debris in and around surface water and concrete footings in the area where wood was treated, temporarily stockpiled debris as necessary, and conducted soil and groundwater assessments. Five groundwater samples contained pentachlorophenol and diesel at levels requiring cleanup.