May 27, 2011
Ms. Kim Jolitz, P.G., C.Hg., Project Manager
Chevron Environmental Management Company 6111 Bollinger Canyon Road San Ramon, CA 94583
Dear Kim:
SUBJECT: Unocal Edmonds Bulk Fuel Terminal – Ecology determination under Agreed Order No. DE 4460
Agreed Order No. DE 4460 between Ecology and the Union Oil Company of California, now owned by Chevron, provides for conducting an Interim Action at the Unocal Edmonds Bulk Fuel Terminal cleanup site. The Order provides that if Ecology determines that the interim action does not constitute the final cleanup action (other than additional compliance monitoring) for the Lower Yard, then Unocal shall complete a draft Feasibility Study (FS) Work Plan within 90 days of Ecology’s determination. See §VII, ¶B.
Ecology has determined that the Interim Action does not constitute the final cleanup action (other than additional compliance monitoring) for the Lower Yard. This determination is based upon our discussions and the statements in Chevron’s report, Draft 2010 annual Groundwater Monitoring Report, Former Unocal Edmonds Terminal, 11720 Unoco Road, Edmonds, Washington, dated Juanuary 25, 2011.
The Report documents that, while significant cleanup has been achieved, petroleum concentrations in ground water exceed cleanup standards at the point of compliance. §10 of the report, Conclusions, states, ARCADIS anticipates Ecology will determine that the interim action did not constitute the final cleanup action, and that the cleanup process will continue with the issuance of a FS Work Plan, FS, and ultimately culminate in a final Cleanup Action Plan.
We discussed the two-year groundwater monitoring data collected between since October 2008, and next steps, at our stakeholder meeting today. I believe we all agreed that significant cleanup has been achieved and our knowledge of the site has been advanced. We also had a good discussion of outstanding issues remaining to be addressed. I have attached a summary of outstanding issues that need to be addressed in the FS Work Plan. Please contact me with clarifications or further thoughts.
Per the requirement of the Agreed order, please submit a draft FS Work Plan on or before August 26, 2011. Extension of this date requires Ecology approval.
Sincerely,
David L. South
Senior Engineer,
Washington State Department of Ecology
cc: (via email)
Rebecca Andresen, Arcadis
Katherine Chesick, WSDOT
Kojo Fordjour, WSDOT
Greg Glass, ECAC
Chip Halbert, Landau Associates
Duane Uusitalo, ECAC
ATTACHMENT
SUMMARY OF CLEANUP ISSUES
UNOCAL EDMONDS BULK FUEL TERMINAL
May 27, 2011
On May 25, 2011, Chevron, ARCADIS, the Washington State Department of Ecology (Ecology), the Edmonds Citizens Awareness Committee (ECAC), and the Washington State Department of Transportation (WSDOT) met to discuss the groundwater data collected between October 2008 and December 2010, as reported in the draft 2009 and 2010 Annual Groundwater Monitoring Reports, currently being finalized. This attachment summarizes key technical issues raised by the aforementioned stakeholders. These issues will be addressed going forward. It is likely there will be substantial additional discussion and development of approaches as work proceeds.
1. Chevron continues to monitor ground water continues at the site. Ground water samples will be collected quarterly at compliance wells and semi-annually at interior wells. All field parameters that are measured by the InSitu 9500 will continue to be measured. It was agreed other monitored natural attenuation parameters previously measured were unlikely to provide useful information. Hence, data for these parameters will no longer be collected.
2. Chevron is performing a tidal and aquifer study at the site. Data have been collected and are being reduced. A technical report on the data will be circulated when ready. The final data will be reported in the draft Feasibility Study (not the FS work plan, the FS itself).
3. Chevron plans to perform investigations of the extent of free product that has been observed in MW-510. A draft work plan for this work will be submitted to Ecology by June 30, 2011. Field work is anticipated to be in August 2011.
4. High petroleum concentrations remain in soil in the vicinity of the WSDOT storm drain that traverses the site. There is concern the concentrations are an ongoing source to ground water and could be indicative of free product. Plans for assessing this concern are to be included in the draft FS work plan.
5. Petroleum concentrations exceeding cleanup levels are observed in ground water from multiple compliance wells. Two alternate working hypotheses were proposed to explain this data. One is that the elevated concentrations result from mobilizing petroleum sorbed to soil into ground water by disturbance due to excavation below the water table. The other is that there are remaining sources that have not been discovered. The draft FS work plan is to propose plans to assess these two alternate working hypotheses.
6. A concern was expressed that there is not sufficient data regarding seasonality and long-term cyclical trends. The ongoing monitoring data will provide additional information in this regard. Addition of wells MW-143 and MW-126 to the monitoring program to obtain information on seasonal trends was suggested. Before adding these wells to the sampling program, more clarification is needed to assess how such data would contribute to selecting a remedy. Due to Ecology staff schedule considerations, this discussion will need to be delayed until July.
7. Concerns were expressed regarding the data used to assess whether the data showed increasing or decreasing trends or stability. Specifically high or low nondetects in early ground water rounds included in the analysis were thought to have unduly influence the results. It was agreed that the analyses in the ground water reports could remain, but that the statements regarding time to achieve cleanup levels would be removed. Future trend analyses will consider the proper inclusion or exclusion of nondetects and other influential points.
8. The stakeholders agreed the technologies put forward in the draft 2010 Annual Ground Water Report provide a good selection. It was agreed to call them “technologies” rather than “remedial strategies”. In addition, in-situ stabilization of contaminated soil to reduce its ability to be a source to ground water will be added as a technology to be assessed. This may be particularly applicable to contamination in the vicinity of the WSDOT storm drain.
9. As noted in the cover letter, the draft FS Work Plan is due to Ecology on August 26, 2011, unless otherwise approved by Ecology. It is anticipated it will take until December 31, 2011, to review the draft, have a stakeholder meeting to discuss it, and finalize the draft. Review may take longer if it is necessary to reach agreement on the necessary work.
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