August 2, 2023

Jim Cooper

Alpha Environmental Services

11080 SW Allen Blvd., Suite 100

Beaverton, OR 97005

RE:  Further Action Required

 for Hartley Motors in Warrenton

 LUST #04-04-0813

Jim Cooper:

The Department of Environmental Quality (DEQ) has completed its review of available file information for the Hartley Motors site, including the Environmental Site Assessment Report prepared by Alpha Environmental Services on November 18, 2021. The Hartley Motors site is located at 120 Harbor Street in Warrenton, Oregon.

DEQ understands that two gasoline underground storage tanks (USTs) were decommissioned by removal from the Hartley Motors site in April 2004. Post-removal confirmation soil sampling identified heavy oils in the west sidewall of the combined excavation pit at a concentration of 19,200 parts per million (ppm). A sample of groundwater that entered the excavation pit identified heavy oils at a concentration of 5,420,000 parts per billion (ppb). The extent of residual soil and groundwater contamination at the site was not determined, and the file remained open in DEQ’s records.

Alpha Environmental conducted additional soil and groundwater sampling at the site in July 2021. Soil samples from two borings advanced adjacent to the location where 19,200 ppm heavy oils had previously been detected found only up to 320 ppm heavy oils, and no petroleum products were detected in the groundwater. However, a soil sample from a separate boring on the east edge of the property encountered heavy oils at a concentration of 22,800 ppm.

The heavy oil contamination does not appear to present an unacceptable risk to occupants of the site, as the heavy oil is nonvolatile and at least five feet below ground surface (bgs). However, the contamination exceeds the risk-based screening level of 2,200 ppm for direct contact by construction workers calculated by DEQ in a January 2016 memo (attached). Construction workers may come into direct contact with soils up to 15 feet bgs while constructing basements, underground parking garages, etc.

At a minimum, the extent of heavy oil contamination in soils at the site exceeding a concentration of 2,200 ppm needs to be determined. If the contaminated soils are left in place, DEQ may require that an Easement & Equitable Servitudes (deed restriction) be recorded with the property deed alerting future owners of the property to the presence of the residual contamination. The owner/operator of the Hartley Motors property may also elect to remove or otherwise remediate the heavy oil contamination to concentrations below 2,200 ppm.

If you have any questions about this letter, please contact me by phone at (503) 229-5369 or by e-mail at kevin.dana@deq.oregon.gov. DEQ appreciates your work on this project.

Sincerely,

Kevin Dana, Cleanup Project Manager

Northwest Region Cleanup Program

Attachment:  January 2016 Heavy Oil Memo

cc:  William Hartley, Hartley Motors

 LUST #04-04-0813 File