BNSF Railway Black Tank Property

The BNSF Railway Black Tank Property is in the Hillyard neighborhood. The site is directly over the Hillyard Trough portion of the Spokane-Valley Rathdrum-Prairie Aquifer. The aquifer provides drinking water to nearly 600,000 residents in the Spokane area.

The site housed a 50-foot-diameter, above-ground, black tank that stored petroleum products. The tank was built as early as 1910 and was actively used until 1988. The tank was connected to piping and other infrastructure facilities. The petroleum products were used in various industrial operations. Residual petroleum products were stored until 2006 when BNSF removed the tank. The site also had an above-ground red tank that was used to store and transfer diesel. The diesel was used to thin bunker C, so it could be pumped into trains.

Petroleum products were spilled or leaked to soil and groundwater during historic site activities.

The primary petroleum products that spilled or leaked were diesel and a heavy oil known as bunker C. An approximately 7-acre plume is on groundwater 170 feet below the ground surface. These petroleum products are very thick, difficult to pump, and challenging to clean up because of the depth and type of contamination.

Because the petroleum products are thick, the contamination is staying on top of the groundwater with very little mixing occurring. Many groundwater monitoring wells are at the site, and drinking water is not affected by the contamination at this time. Monitoring will continue until the cleanup process is complete.

However, it’s important to understand and clean up the contamination while it still remains reasonably isolated, and Ecology will oversee the cleanup process until the site is protective of human health and the environment.

BNSF Railway and Marathon Oil are responsible for the cleanup. BNSF removed the black tank in 2006, along with contaminated soil under and around the tank. BNSF then discovered petroleum products in a monitoring well in 2008.

Ecology entered into an Agreed Order with BNSF and Marathon in 2012, requiring them to conduct a remedial investigation and feasibility study (RI/FS). The RI gathered information about the extent and locations of petroleum contamination in soil and groundwater at the site. The FS evaluates cleanup options.

The draft RI/FS was available for public review and comment May 22 through June 22, 2017. We received comments from 21 people and published our responses. We also sent them to everyone who commented and appreciate their interest and input.

Ecology received four requests for a public meeting during the draft RI/FS comment period, which did not meet the 10 requests we require to justify the costs of holding one. However, when requestors provided contact information, we offered to meet with them individually to answer questions and listen to concerns. No one accepted these offers.

We held a comment period June 4 - July 3, 2018, for an amendment to the legal agreement with BNSF Railway and Marathon Oil. The amendment required the responsible parties to excavate and dispose up to 15 feet of contaminated soil at each of the five surface soil contamination areas in 2018 before the cleanup action plan is final. This interim cleanup action was necessary to keep the North Spokane Corridor freeway construction on schedule. Ecology responded to comments from eight people.

We held a comment period May 13 - June 11, 2019, for the following documents:

• Cleanup Action Plan -- explains the cleanup methods we proposed for this site and includes a Scope of Work and Schedule for BNSF and Marathon to complete cleanup
• Consent decree -- legal agreement requiring the parties responsible for cleanup to enact the cleanup plan
• SEPA documents -- we have reviewed the cleanup actions using the SEPA checklist, and decided they won’t adversely affect people or the environment (Determination of Non-significance)