Edmonds UNOCAL / Chevron Cleanup

UNOCAL EDMONDS BULK FUEL TERMINAL MTCA CLEANUP UPDATE, June 2011

By Greg Glass

 

Starting the Feasibility Study.  Chevron submitted a Draft Year 2 Ground Water Monitoring Report to Ecology on January 25, 2011.  After compiling review comments from Ecology, WSDOT, and ECAC, David South, Ecology’s site manager, convened a stakeholder meeting on May 25, 2011 to discuss that draft report and related matters.

 

After the stakeholder meeting, Ecology issued a formal determination that the Lower Yard Interim Actions did not constitute a final site cleanup, based on continued exceedances of cleanup levels at multiple Point of Compliance ground water monitoring wells.  That letter (see separate posting under Additional Info on the left of the blog) dated May 27, 2011 started a 90 day period for Chevron to prepare and submit a work plan for a Feasibility Study (FS) that will identify and evaluate various alternatives to achieve final site cleanup.  The Draft FS Work Plan is thus due by August 26, 2011.  David South forecast that reviews of the FS Work Plan would not be completed until December 2011, indicating that a revised Final Work Plan would be ready around February 2012.  Allowing for completion of Draft and Final Feasibility Study Reports, selection of a cleanup alternative and preparation of a Cleanup Action Plan by Ecology, and required design studies, it now appears likely that further physical cleanup actions in the Lower Yard will not occur before 2014.

 

Chevron’s Year 2 Ground Water Monitoring report included a proposal to continue ground water monitoring activities at the site.  Quarterly sampling of the POC wells, and bi-annual sampling of interior wells, was proposed.  Sampling of POC wells for the first quarter of 2011 occurred in March (see summary below); second quarter sampling of both POC and interior wells will occur in June.  ECAC considers it critically important to continue ground water monitoring so that trends in TPH contamination can be effectively evaluated.  Several comments on the proposal for continued ground water monitoring are still being discussed with Ecology and Chevron.

 

It was clear at the completion of the two years of post-Interim Action ground water monitoring that Lower Yard cleanup was not complete.  Before the formal initiation of the FS process, Chevron prepared a Draft Aquifer Testing Work Plan, submitted to Ecology on November 19, 2010.  The Final Work Plan was submitted on January 25, 2011 and field work for tidal influence and aquifer testing was completed in May.  The extensive Lower Yard excavations and backfilling changed the characteristics of soils throughout much of the Lower Yard.  The FS evaluations of ground water cleanup options will require an updating of aquifer properties; this aquifer testing program is a first example of identifying and filling data gaps for completing the FS.  Full evaluations of the data collected in this field program will occur within the FS.

 

Petroleum product (LNAPL) has been consistently found at one monitoring well, MW-510.  Chevron will submit a plan to Ecology by June 30, 2011 to further investigate the extent of NAPLs in this area near the former slops pond. Except in unusual circumstances, NAPLs must be removed for site cleanup to be considered complete.  Field work to carry out the NAPLs Work Plan investigations is expected to occur in August 2011.  Final NAPLs cleanup actions are expected to be part of the FS evaluations.

 

Ground Water Monitoring Results, 1^st Quarter 2011.  Chevron’s May 12, 2011 monthly progress report to Ecology included a summary of the results of ground water monitoring that occurred in March (first quarter 2011 sampling).  Under Chevron’s proposed scope for continued ground water monitoring, samples were collected and analyzed in Q1 2011 only for the 21 Point of Compliance (property boundary) wells.

 

Product (LNAPL) was still found at well MW-510 in the vicinity of the former slops pond location; therefore, no ground water sample was collected for analysis at that well.

 

The total TPH concentrations at the Point of Compliance (POC) perimeter wells continue to show multiple exceedances of default cleanup levels at locations spread across most of the Lower Yard property boundary.  LM-2 at the northern corner of Detention Basin 1 had the highest total TPH concentration (3,925 ug/L) among sampled wells in the last round of the two-year post-Interim Action monitoring program, in October 2010.  It still had the highest concentration among wells sampled in March 2011, at 2,625 ug/L.  Chevron collected an additional sample at LM-2 in December 2010 to check the high value reported in October 2010; the December total TPH of 2,405 ug/L confirmed the general trend toward higher concentrations in recent sampling rounds.  MW-129R, near the southeast corner of DB-1, had 2,275 ug/L total TPH; it has exceeded 2,000 ug/L for 9 of the last 10 sampling rounds.  Wells MW-135 and MW-136, at 695 and 643 ug/L total TPH, had substantially decreased concentrations from previous rounds and reflected the greatest reductions.  Along the western boundary, MW-104 at 1,214 ug/L showed a substantial increase from the last 3 rounds, and continued an “up-and-down” (seasonal?) pattern.  MW-147 at 1,524 ug/L continued a pattern of frequent higher concentrations at that location, except for lower mid-summer values (seasonality?).  Additional years of monitoring will be required to confirm any seasonal patterns in ground water TPH concentrations.

 

 As part of its review of Chevron’s Year 2 Ground water Monitoring report, ECAC prepared tables summarizing the TPH results for two years of ground water monitoring.  That summary is provided below and gives results by sampling date and by well over 11 rounds of sampling.  Ecology will meet with ARCADIS, Chevron’s consultant, in late June 2011 to make final revisions to the Year 2 Ground Water Monitoring report in response to reviewer comments, as discussed at the May 25^th stakeholder meeting.  That report will become primarily a data report rather than an evaluation and interpretation report.

 

Feel free to contact:  HYPERLINK "mailto:gglassenviro@comcast.net" gglassenviro@comcast.net

 

 

	UNOCAL Edmonds Former Bulk Fuel Terminal
	Summary of Ground Water Monitoring Results
	Round 1 through Round 11 (Oct 2008 - Oct 2010)
	TPH Exceedances of Default Ground Water Cleanup Levels:
	Summary by Sampling Round
			POC Wells [n=21]
			number	low	high	max location
	Sampling Round			(ug/L)	(ug/L)
	Oct 2008		6	909	8,330	MW-501
	Dec 2008		4	968	5,407	MW-510
	Feb 2009		10	595	16,380	MW-510
	Apr 2009		9	779	22,930	MW-510
	June 2009		9	915	25,090	MW-510
	Aug 2009		7	1,066	18,080	MW-510
	Oct 2009		11	715	2,720	MW-147 (a)
	Jan 2010		8	845	3,105	MW-104 (a)
	Apr 2010		7	908	2,015	MW-129R (a)
	Jul 2010		8	592	2,275	MW-129R (a)
	Oct 2010		7	924	3,925	LM-2 (a)
			Interior Wells [n=19]
			number	low	high	max location
				(ug/L)	(ug/L)
	Oct 2008		9	701	1,697	MW-502
	Dec 2008		5	562	1,438	MW-502
	Feb 2009		6	748	2,005	MW-143
	Apr 2009		6	534 [533]	1,503	MW-502
	June 2009		5	512 [413]	1,175	MW-143
	Aug 2009		3	539 [561]	847 [755]	MW-514
	Oct 2009		4	534 [594]	1,013	MW-507
	Jan 2010		5	544	1,230	MW-502
	Apr 2010		4	646	1,565 [1,875]	MW-143
	Jul 2010		3	534	1,585	MW-143
	Oct 2010		2	575	615	MW-507
	(a)	LNAPLs detected at MW-510, no sample collected for
		lab analysis
	[533]	A second TPH concentration in brackets is for a field
		duplicate sample

 

 

UNOCAL Edmonds Former Bulk Fuel Terminal                 Summary of Ground Water Monitoring Results:  POC Wells   Round 1 through Round 11 (Oct 2008 - Oct 2010)                             TPH Exceedances of Default Ground Water Cleanup Levels:   Summary by Perimeter Well Over 11 Sampling Rounds                     number low high         (ug/L) (ug/L)   POC Well [n=21]  (a)                     MW-150   1 715                 MW-149R   1 775                 MW-524   0                   MW-147   8 968 2,720               MW-523   0                   MW-8R   0                   MW-522   3 779 955               MW-20R   2 866 1,087               MW-104   5 916 3,105               MW-101   0                   MW-518   10 697 [709] 1,403               MW-139R   0                   MW-510 (b)   11 3,980 25,090 (b)               LM-2   8 915 3,925               MW-108   0                   MW-109   0                   MW-129R   9 1,675 4,425               MW-501   5 592 8,300               MW-500   6 595 3,000               MW-135   8 845 2,625               MW-136   9 1,535 3,725                                       NOTES                       (a) POC wells are listed in spatial order, from southwest     to southeast site boundary                 (b) LNAPLs detected on and after October 2009 at MW-510,     no sample collected for lab analysis                 [709] A second TPH concentration in brackets is for a     field duplicate sample           UNOCAL Edmonds Former Bulk Fuel Terminal                 Summary of Ground Water Monitoring Results:  Interior Wells   Round 1 through Round 11 (Oct 2008 - Oct 2010)                             TPH Exceedances of Default Ground Water Cleanup Levels:   Summary by Interior Well Over 11 Sampling Rounds                     number low high         (ug/L) (ug/L)   Interior Well [n=19]  (a)                     MW-143   6 770 2,005               MW-519   0                   MW-520   1 731                 MW-521   0                   MW-511   0                   MW-512   6 534 [533] 748               MW-513   8 534 [594] 932               MW-514   11 575 1,578               MW-515   1 947 [975]                 MW-516   1 801                 MW-517   0                   MW-502   8 512 [413] 1,700               MW-503   0                   MW-504   1 701                 MW-505   0                   MW-506   0                   MW-507   8 562 1,142               MW-508   1 745 [645]                 MW-509   0                                           NOTES                       (a) Interior wells are listed in approximate spatial order,     from southwest to southeast of Lower Yard (in     original MNA plume layout, west-central-east plumes,     from upgradient to downgradient)                 [533] A second TPH concentration in brackets is for a     field duplicate sample

David South Comments on UNOCAL/Chevron Interim Actions

 

 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.