Inchelium, WA | Used Oil & Waste Clean Up at Inchelium Wood Treatment Plant

In 2015–2016, the Colville Tribes Environmental Trust Department conducted groundwater monitoring and waste oil removal at the Inchelium Wood Treatment Plant (IWTP) site and the nearby Ice Mine Rock Fill area, located near Inchelium, WA. These actions helped track legacy contamination from former wood-treating operations and ensure site safety.

Background

The IWTP was built in the mid‑1980s on land acquired by Colville Tribal Enterprise Corporation and operated until 2006. It used chromated copper arsenate (CCA) to preserve wood—a process that generated hazardous CCA-contaminated soil, concrete, tanks, ground water and sumps. Inspections by EPA in the mid‑2000s identified violations of federal hazardous waste laws under RCRA, including unpermitted hazardous waste storage and run-off onto surrounding soil.

The site contained chemicals such as chromium, copper, arsenic, and lead at levels significantly above background and tribal cleanup thresholds.

Nespelem, WA | Side Dump Truck Turnover

In 2015, a delivery at the Lucy F. Covington Government Center in Nespelem resulted in an unexpected spill of fuel/oil contaminants on-site. Known locally as the “Accidental Delivery,” the incident prompted immediate soil testing and cleanup by the Environmental Trust team.

The Colville Tribes Environmental Trust Department responded swiftly to contain and sample the affected area. Cleanup actions followed tribal and federal safety standards to ensure no lasting environmental impact.

Tribal Tribune article “Accidental Delivery.”

Omak, WA | Unauthorized Transformer Dump

On or around July 9, 2015, a spill incident occurred near the Colville Tribes Omak Longhouse, located at 25B Mission Road, Omak, WA. The event was triggered by the theft and improper handling of an out-of-service transformer, which had an approximate 25-gallon capacity of mineral oil.

The transformer was reportedly chained to a vehicle and dragged along Mission Road and North End Omak Lake Road, resulting in intermittent oil discharge along both asphalt and gravel surfaces.

Milepost 136.5, Keller, WA | CHS Tanker Incident

On May 19, 2015, a fuel tanker truck owned by CHS overturned on State Route 21 at Milepost 136.5 near Keller, WA, releasing approximately 2,700 gallons of gasoline and 60 gallons of diesel. The spill occurred near the San Poil River, raising concern for nearby water quality.

The Colville Tribes determined CHS to be the responsible party for the release, which posed a threat to navigable waters of the U.S. Since the time of the incident, the Colville Tribes Environmental Trust Department has worked closely with the U.S. Environmental Protection Agency (EPA) on emergency response and cleanup actions.

Work at the site has included fuel containment, environmental assessments, and long-term planning for remediation. Environmental Trust remains actively involved in both a technical advisory and regulatory role and will continue oversight until final cleanup is complete.

Nespelem, WA | Historical Wood Treatment Contamination

In 1980, a large spill of pentachlorophenol (PCP) and diesel occurred at the Nespelem Post & Pole (NPP) facility. About 3,000 cubic yards of contaminated soil were removed and transported two miles west to the Mineral Hill site, where it was expected to be detoxified through landfarming. However, a significant volume of contaminated soil remained on-site at NPP, mostly at depths greater than 15 feet.

Project Funding

• Environmental investigations and hot spot removals (since 2005): EPA 128(a) Tribal Response Program

• Cap design: EPA Area-Wide Planning Grant + 128(a) support

• Soil relocation and compaction: CCT Cleanup Fund + 128(a)

• Engineered cap construction: EPA Brownfields 104(k) Grant + 128(a)

Inchelium, WA | Contamination from 1950s–2006 | Clean Up 2014–2016

Site History

The IWTP site began as an equipment maintenance facility in the mid-1950s under Lincoln Lumber Co., later operated by Boise Cascade. In the mid-1980s, after the Tribes acquired the property, Colville Tribal Enterprise Corporation (CTEC) converted it into a pressurized wood treatment plant. From 1985 until 2006, CCA (chromated copper arsenate) was used to pressure-treat wood, creating soil, concrete, and groundwater contamination. In 2006, CTEC ceased operations due to ongoing environmental liabilities and financial losses.

Regulatory Findings

A 2006 EPA inspection exposed major environmental violations:

• Unpermitted storage of CCA waste and used oils

• Lack of staff training and safety equipment

• Use of unlined drip pads and unregistered waste generation

The resulting Consent Agreement and Final Order (CAFO) required:

• EPA-approved closure and hazardous waste plans

• Sealing and cleaning tanks, sumps, and drip pads

• Proper disposal of waste and financial assurances

• Cleanup actions where CCA had contaminated soil, sump areas, and two under-concrete drip zones

Groundwater tests confirmed elevated levels of CCA contaminants and petroleum products, although monitoring since 2006 shows levels are stable or declining - posing no imminent threat to the drinking water aquifer or Stranger Creek.

Cleanup & Remediation Efforts

After slow progress through 2009–2012, active cleanup began in summer 2014, led by the Environmental Trust Department:

• Hired a certified hazardous-waste contractor

• Removed and containerized FO35 hazardous waste from storage tanks and sumps

• Excavated CCA-contaminated soil and concrete, shipping it off-site for disposal

• Addressed used-oil containment: backfilled pits and installed new groundwater monitoring wells

• Started annual groundwater and site monitoring, including a five-year review

• Brought on an ETD Remediation Specialist for on-site quality control

The goal is to cleanup soil and groundwater to commercial/industrial standards.

Project Funding & Administration

• Cleanup financed through a $3 million loan from the Qwam Qwmpt Restoration Fund (2.5% interest, 10-year repayment from timber sales)

• Oversight and funding handled by ETD, prioritizing major contamination sites across the Reservation

Next Steps & Site Use

Future use is still under consideration. The site will meet industrial/commercial safety levels. Continued groundwater monitoring will guide decisions on deeper aquifer risks and plume stability.

Omak, WA | Used Oil & Fuel Spill | Cleanup Initiated Summer 2007

The Colville Indian Precision Valley (CIPV) site is located at 729 South Jackson Street and 1100 East 8th Avenue in Omak, Washington. In the summer of 2007, CIPV personnel discovered oil-stained soil near a group of discarded aboveground storage tanks located behind the purchasing building.

Discovery and Contamination

Upon investigation, eight leaking tanks were found in a 65 by 50-foot area. These tanks contained a mixture of hydraulic oil, used oil, and fuel, and were visibly leaking onto the surrounding soil. Soil sampling confirmed contamination in the impacted area.

Cleanup and Remediation

Cleanup activities included:

• Removal of remaining liquids from the aboveground tanks

• Excavation of oil-impacted soils

• Off-site disposal of contaminated soil at an approved facility

• Backfill and compaction using clean sand sourced from CIPV’s own fill stockpile

Current Status

The impacted area has been restored and stabilized. No further contamination has been observed since the remediation was completed.

Multiple Locations – Colville Reservation

On the Colville Indian Reservation, a number of abandoned residential and commercial buildings were identified for demolition or redevelopment. Before any demolition could begin, inspections were conducted to identify hazardous materials commonly found in older structures.

These inspections focused on materials like asbestos, lead-based paint, and electrical or lighting components that may contain harmful substances. Additional materials tested included:

• Wood, glass, concrete, and metal

• Fiberglass insulation and flooring

• Roofing, piping, and ducting

• Railings and plumbing

The purpose of these inspections was to determine the presence of hazardous building materials and help guide the safe handling, disposal, or treatment of these items before demolition. This process also supports proper waste characterization, in line with environmental and safety regulations.

By identifying these hazards early, the Colville Tribes ensured that modernization and redevelopment activities could move forward safely, while protecting workers, nearby residents, and the surrounding environment.