Chevron Pipe Line Company Pasco Bulk Terminal

The former Chevron Pipe Line Company Pasco Bulk Terminal Site is 33 acres. Marathon Petroleum Corporation (Marathon) now owns the site; however, Tesoro Logistics Operations LLC (Tesoro) is responsible for cleanup. The Tidewater Terminal Company operates pipelines at the site.

The site has 18 tanks that store petroleum products above ground. It has been a bulk fuel storage facility since 1950. Fuel is transported to and from the terminal by pipelines, fuel trucks, and a barge loading and unloading dock on the Snake River next to the terminal.

In 1976, a release of 665 barrels, or about 28,000 gallons of petroleum, was reported at the site. Since then, previous owner Chevron documented 10 additional petroleum releases. Of these post-1976 releases, two were over 1,000 gallons.

In the mid-1980s, petroleum products were found in groundwater monitoring wells at the site, and petroleum sheen was seen along the Snake River bank. Investigations found that a pipe transferring aviation fuel was leaking. All terminal-related pipelines were removed from just below the ground surface in the area of the sheen. Contaminated soil and fuel product were removed from just below the ground surface and along the shoreline and replaced with clean soil. Additional actions were taken to address the groundwater contamination, and more monitoring wells were installed.

In 2000, a gasoline release was found at the site coming from a hole in the Tidewater transfer pipeline that moves fuel to the terminal. Tidewater conducted soil and groundwater investigations and work to clean up contaminants.

We investigated the site and added it to the Hazardous Sites List in 2000.

In August 2009, Ecology entered into an Agreed Order with Chevron and Tidewater that required them to conduct a Remedial Investigation and Feasibility Study at the site that they completed in 2011. The Remedial Investigation looked at past and current site conditions and the effectiveness of past cleanup actions. The Feasibility Study evaluated cleanup options.

Following this investigation and review of cleanup options, Ecology published the first Cleanup Action Plan. We chose cleanup alternative 1, which allowed remaining contaminants to dissipate naturally over time, required the upkeep of physical barriers that limit access and land use, and provided signage for the restricted area. Alternative 1 includes a restriction on groundwater use. No groundwater may be taken from the site except for use related to the cleanup, such as groundwater monitoring. Additionally, site owners are required to monitor the groundwater and confirm that contamination is being reduced through the natural process. This monitoring will continue until results meet state standards for at least one year.

In 2016, Ecology negotiated an Agreed Order with Tesoro, the company that bought the terminal from Chevron. This order required Tesoro to complete a Supplemental Remedial Investigation and Feasibility Study, which was published in 2021. This investigation provided more information about past and current site conditions, cleanup actions that have been completed and their effectiveness, and what needs to be done at the site to further protect human health and the environment.

In 2023, Ecology published the second Cleanup Action Plan using the updated information from the Supplemental Remedial Investigation and Feasibility Study. The plan describes the actions Tesoro is taking to finish cleaning up the site:

• Increase oxygen in groundwater by adding sleeves with oxygen-releasing compounds to the monitoring wells. Oxygen helps break down petroleum in groundwater more quickly.
• Continue monitoring groundwater quality to track cleanup progress.
• Maintain barriers to keep the public from accessing the site and contacting contamination, including signs, fences, and prohibiting groundwater use.

The estimated cleanup time for this plan is 5 to 15 years at a cost of $786,400. Marathon acquired the terminal from Tesoro in 2018, but Tesoro continues to manage the cleanup.