Site Summary for Cheven Asphalt also known as Paramount Petroleum and Zenith (Site)
ECSI 1281
Jim Orr, Cleanup Project Manager
Site Location and Description:
• The Site was constructed in 1947, and the facility has operated formerly as
a petroleum refinery and now as a bulk storage facility. See the attached Figures 1, 2, 3, and Apex Figure 2 with Naphtha area monitoring wells.
• The site is 600 ft away from the Willamette River, and groundwater discharges within the boundaries of the Portland Harbor Superfund Site.
Site History:
The following is a summary of the site's regulatory history.
• 1983/1984. The EPA conducted a preliminary assessment and issued a No Further Remedial Action.
• 1994. Chevron agreed with DEQ to enroll in the Voluntary Cleanup Program (VCP) to investigate and remedy impacts resulting from releases at the Terminal.
• 1995. Chevron terminated the VCP agreement.
• 2002. DEQ recommended conducting an expanded preliminary assessment (XPA) at the Terminal. Chevron signed a VCP letter agreement and conducted the XPA.
• 2006. Chevron entered into a voluntary agreement with DEQ to perform an SCE for the entire Terminal.
• July 2010. DEQ issued an SCD for the Terminal. The SCD determined that stormwater and groundwater did not pose a significant risk to the Willamette River Superfund Cleanup.
• July 2011. Paramount Petroleum reported a release of approximately 19,150 gallons of Light Naphtha. Light Naphtha is a complex combination of hydrocarbons produced by the distillation of crude oil. Light Naphtha is rich in paraffin hydrocarbons and is commonly used as a feedstock for making petrochemicals, such as ethylene and propylene. It is also used as a solvent in the paint and coatings industry and as fuel for gasoline engines.
• DEQ and immediately began investigation and cleanup activities.
• January 2020. DEQ provided a memo supporting the proposed infiltration from the new loading rack. (Attached Reference Link) These findings were shared with DEQ Water Quality.
• July 2011 through September 2022. Paramount Petroleum and subsequent owners implemented measures to address the Paramount 2011 naphtha release in coordination with the DEQ SPILLS program.
• October 2022. Zenith entered into an agreement with DEQ for enrollment in the VCP to investigate and remediate impacts resulting from the Paramount 2011 light naphtha release.
• October 2023. At the request of DEQ, the October 2022 VCP agreement was terminated.
• Zenith and DEQ entered into an Agreement for conditions related to the Paramount 2011 light naphtha release.
Portland Harbor Source Control Decision
Chevron, a former owner and operator of this site, conducted a Portland Harbor Source Control Evaluation to assess potential impacts to the Willamette River. A program of stormwater monitoring and catch basin cleanout was established. After completing this work, DEQ issued a Source Control Decision (SCD) in 2010, documenting the agency's decision that the site does not pose a risk of recontamination of future remedial actions in the Willamette River. The SCD included source control measures and the basis for DEQ’s decision. The document was reviewed by partner agencies, including the City of Portland and the US Environmental Protection Agency (US EPA), in accordance with established procedures detailed in the memorandum of understanding between US EPA and Oregon DEQ for Willamette River Source Control. DEQ finalized the decision in 2010 after considering reviewer comments. (see link to SCD in References).
A release of approximately 19,150 gallons of naphtha in the northern portion of the Terminal was reported by Paramount Petroleum (Paramount) to DEQ in July 2011. Paramount and its successors, including but not limited to Zenith, have performed remediation and monitoring activities to address the naphtha release. These activities have resulted in the approximate recovery of approximately 93 percent of the released naphtha. The spill required cleanup by extracting vapor and water from soil and groundwater near the spill. The extraction system was removed in 2013 because all free product were less than 0.1 feet at all monitoring wells.
The spill response was moved into the Cleanup Program from the Spills Unit. The requirements for product thickness were modified to achieve less than 0.01 feet of product. Monitoring well W-31 continued to have product levels greater than 0.01 feet and an automatic skimmer was installed, recovering 100 gallons of product in the fourth quarter of 2024 and the first quarter of 2025. Product monitoring and recovery will continue until product levels are below 0.01 feet and product recovery is insignificant. The site reports separate phase product (free product) monitoring results quarterly. Zenith continues to coordinate with DEQ for the final closure of the naphtha release. The location of the spill area and monitoring wells are shown on Apex Figure 2.
Source Control Evaluation Reopening
In 2023, DEQ determined that the Paramount 2011 light naphtha release constituted a change in conditions that may affect the conclusions of the 2010 SCD; therefore, DEQ requested a focused SCE to evaluate conditions related to the Paramount 2011 light naphtha release. As a first step for the DEQ required the development of a Work Plan that was submitted in May 2020.
The Work Plan did not propose any additional screening of the impact of the light naphtha spill to groundwater. DEQ and EPA disagreed with the findings of the Work Plan. DEQ will propose additional groundwater screening of wells in the Light Naptha spill area for petroleum hydrocarbons in the spill area to support a focused Source Control Decision (only evaluation of groundwater impact from light naphtha and metals.
February 2025. DEQ will request groundwater monitoring of wells downgradient of the light naphtha spill for C10 to C-12 polynuclear hydrocarbons (light phase constituents) and metals. The results of this monitoring will be screened against Portland Harbor risk levels to allow a source control decision.
References Your DEQ Online Links:
January 30, 2023 Naptha Release Area Status Report
https://ormswd2.synergydcs.com/HPRMWebDrawer/Record/6307507
June 6, 2024 EPA Memo Comments for Zenith Focused SCE
https://ormswd2.synergydcs.com/HPRMWebDrawer/Record/6870593
May 2009 Source Control Evaluation
https://ormswd2.synergydcs.com/HPRMWebDrawer/Record/6720947
June 1, 2020 DEQ Memo for Zenith Loading Rack Infiltration
https://ormswd2.synergydcs.com/HPRMWebDrawer/Record/6307504
2010 Source Control Decision Text Only