UNOCAL EDMONDS SITE
UNOCAL operated a Bulk Fuel Terminal in Edmonds, Washington from 1923 to 1991. In addition to the large volumes of various fuels handled at this site for almost 70 years, an asphalt plant was also in operation at the site for about 20 years. The site is located near Puget Sound, adjacent to Willow Creek and the Edmonds Marsh. A fish hatchery is also located at the southeast corner of the property.
The UNOCAL Edmonds site includes an Upper Yard where storage tanks and distribution piping were located and a Lower Yard with offices, rail and truck loading facilities, the asphalt plant and associated warehouse, and storm water handling facilities (Detention Basins 1 and 2). After extensive excavation of contaminated soils, the Upper Yard was sold and is now a residential condominium development. The Lower Yard has been identified for use as a multimodal transportation hub, including relocation of the Edmonds ferry. A purchase and sale agreement for the Lower Yard has been completed between UNOCAL (since purchased by Chevron) and the Washington State Department of Transportation (WSDOT).
Site characterization studies of the Lower Yard documented extensive contamination of soils and ground water with TPH and related contaminants. Floating product (LNAPLs) was also detected at multiple wells over large portions of the Lower Yard. After early attempts to recover LNAPLs, a series of Interim Actions began in 2001 and included excavation and removal of contaminated soils, removal and treatment of contaminated ground water, and product removal in localized areas of the Lower Yard. The large Detention Basin 1 was also dewatered and cleaned out. During 2007-2008 an extensive Interim Action covering most of the Lower Yard was undertaken, intended by Chevron to complete active site remediation. A post-Interim Action two-year ground water monitoring program started in October 2008. Ground water chemistry is being monitored at 40 wells to track compliance with ground water cleanup levels at the property boundary (the MTCA point of compliance), determine if remaining ground water contamination within the Lower Yard is naturally attenuating, detect any re-occurrence of LNAPLs, and determine if residual soil contamination will adversely affect ground water quality.
PUBLIC PARTICIPATION GRANT HISTORY
Reflecting community interest and concerns regarding cleanup of the UNOCAL Terminal Site, the Brackett's Landing Foundation established the Edmonds Citizens' Awareness Committee (ECAC) to support citizen involvement in the cleanup process. Brackett's Landing Foundation has applied for and received a series of Public Participation Grants from Ecology, starting in 1995. Those grants have allowed ECAC to hire its own technical consultants to review site information, provide technical review comments to Ecology, and help educate the community about site contamination issues. The grants have also supported citizen participation in the extended MTCA cleanup process, so that Ecology can take community interests into account.
The formal cleanup process at the UNOCAL Edmonds site started in 1993 when Ecology and UNOCAL signed an Agreed Order for completion of a Remedial Investigation and Feasibility Study. The time needed to complete site cleanup has far exceeded what was foreseen when ECAC received its first grant in 1995. Ecology has provided ongoing community support through continuation grants as the cleanup process has been repeatedly extended. Whether the 2007-2008 Interim Actions successfully completed active remediation, or whether even more remediation is needed, will be determined based on evaluations of the current two-year ground water monitoring program. ECAC has applied for a continuation grant for 2009-2011 to continue oversight of this monitoring program and data evaluations and support community education and participation through final site cleanup.
CURRENT GRANT ACTIVITIES
Monitoring of Site Cleanup. Mobilization for starting the Lower Yard Interim Actions took place in July 2007. Given the relatively late seasonal start for cleanup activities, and in order to maximize work during favorable weather, a public comment period was held concurrently with the start of the Interim Actions. Remedial actions were completed by September 2008 with installation of a large number of new ground water monitoring wells in preparation for a two-year monitoring program. Throughout both Phase I and Phase II of the Interim Actions, ECAC made site visits approximately weekly to observe cleanup activities, identify issues needing resolution, and report to the community on progress through blog postings. Our technical consultant provided a cumulative site visits log to ECAC throughout the cleanup process to reflect site status. ECAC participated in several oversight visits by Ecology’s site manager. After completion of Phase I, ECAC’s technical consultant met with ARCADIS’ staff at the Lower Yard to identify locations for collecting additional site characterization information to address data gaps. As analytical results became available from sidewall and floor sampling at soil excavations, ECAC reviewed those results and discussed them with ARCADIS’ staff during frequent site visits.
Review of Site Reports. Near the end of the previous grant period, in May/June 2007, a final Interim Action work plan was in preparation. Ecology and UNOCAL/Chevron negotiated a new Agreed Order to cover additional Lower Yard cleanup activities. At the start of the current 2007-2009 grant period, ECAC submitted written comments to Ecology during the public comment period on the Interim Action plans as well as the Remedial Investigation/Supplemental Remedial Investigation and new Agreed Order. ECAC had been an invited participant in a series of meetings among Ecology, UNOCAL/Chevron, and stakeholders leading up to the public comment period. Several recommendations by ECAC were adopted into the Interim Action work plans.
Lower Yard cleanup actions during the 2007-2008 Interim Actions were documented in two As-Built Reports by Chevron, corresponding to the two phases of remediation. ECAC submitted written review comments to Ecology on the Phase I As-Built Report (January 8, 2009) on February 12, 2009. Comments on the Phase II As-Built Report (May 13, 2009) will be submitted by August 2009, in the next grant period.
During development of the Interim Action work plans, ECAC reviewed all site information to identify possible data gaps and made a presentation on that issue to the working group. Decisions on data gaps requiring additional investigation were deferred at that time pending completion of Interim Action soil excavations, which were deemed likely to expand somewhat beyond planned excavation areas based on field observations and sidewall sampling. After completion of Phase I of the Interim Actions, Chevron prepared a report titled “Evaluation of Lower Yard Phase I Data and Work Plan for Additional Site Investigation” (May 30, 2008). ECAC submitted comments on that work plan to Ecology on June 11, 2008 and recommended three additional data gap areas where further site characterization was warranted. Additional information was collected in two of those three areas; at one, the former asphalt warehouse, additional soil excavations were performed. At the third recommended area, the former slops pond, no additional information was collected. A new ground water monitoring well (MW-510) was installed and has shown the highest TPH contamination of any of the 40 monitoring wells currently being sampled.
Chevron submitted a report titled “2008 Additional Site Investigation and Groundwater Monitoring Report” (March 27, 2009) that documented the findings of the additional site characterization investigations after completing Phase I of the Interim Actions, and also summarized the data from the first 2 of 12 planned rounds of post-Interim Action ground water monitoring. This report included an evaluation of the residual contamination near the WSDOT storm drain line in the Lower Yard which was not removed during the Interim Actions. ECAC submitted comments on this report to Ecology on April 23, 2009.
Meetings. ECAC met periodically with its technical consultant to discuss the status of site cleanup activities, evaluations of recent sampling results, and plans for community updates via the weblog. Ecology, Chevron and its consultant ARCADIS, and ECAC, along with WSDOT, continued the cooperative approach established earlier through the Technical Work Group to identify and discuss issues as they arose. ECAC participated in a stakeholders meeting in Edmonds on March 12, 2008 at which ARCADIS presented an overview of Phase I of the Interim Actions. After review comments on the Phase I As-Built Report were compiled, ECAC participated in a meeting at ARCADIS’ offices on March 17, 2009 to discuss the review comments and agree upon report revisions.
Long-Term Ground Water Monitoring Program Data Reviews. The post-Interim Action two-year ground water monitoring program started with round 1 sampling in October 2008. A total of 40 wells are being sampled and analyzed each round, with additional wells observed for ground water elevations and product occurrence. During the current grant period results from the first 4 of 12 planned rounds of sampling were reported by Chevron (as attachments to monthly progress reports to Ecology). Chevron is to submit detailed ground water data evaluation reports to Ecology at the end of Year 1 and Year 2. ECAC reviewed the results from each round as they were reported, and started looking at within-well trends as of round 4. Multiple wells continue to show TPH concentrations above the ground water cleanup levels, many within the perimeter point-of-compliance well system. The analytical lab performing ground water analyses was changed after round 2 to achieve lower detection limits. ECAC has called attention to the fact that the TPH type designation changed at several wells after this change in analytical laboratory. Ground water cleanup levels are affected by the type(s) of TPH detected; this issue will need to be addressed as part of future ground water data evaluations. In addition to the perimeter compliance monitoring wells, additional wells in the interior of the Lower Yard are being sampled to track changes at several historically-defined “plumes” of TPH contamination. The data through round 4 are generally not consistent with the spatial continuity assumed for ground water contaminant plumes for two of the three sets of interior wells. Future evaluations of natural attenuation processes may have to take that pattern into account and focus on within-well evaluations.
Weblog. During the current grant period ECAC established a website ( HYPERLINK "http://www.ecac-unocal.org" www.ecac-unocal.org) as a primary means of keeping the community informed about the status of site cleanup, issues needing resolution, and opportunities to participate and comment on the overall cleanup process. As of the end of the current grant period there have been several thousand hits on this blog site. Biographies of key ECAC officers and consultants and a series of historic site photos are posted on the blog. Periodic postings kept the community up to date on the Interim Action site remediation activities and the results for each round of post-Interim Action ground water monitoring. Time trend charts of TPH concentrations at selected wells were included in the posting after round 4 sampling as a means of allowing citizens to easily visualize current conditions at the Lower Yard. Copies of ECAC written comments submitted to Ecology on reports submitted by Chevron are also being posted on the blog.
SITE STATUS AS OF JUNE 30, 2009
Attempts at floating product (LNAPLs) recovery in the Lower Yard date back to 1987. After a series of more limited and localized cleanup actions, the 2007-2008 Interim Actions completed an extensive excavation program to remove contaminated soils, while also removing free product and removing and treating a large quantity of contaminated ground water during excavation dewatering. The excavation areas and volumes of soils removed were considerably larger than identified during planning of the Interim Actions, based on site characterization information. Buried drums with product and assorted debris were found buried in the southeast Lower Yard, an area without significant historic operations associated with Bulk Fuel Terminal operations.
Some TPH-contaminated soils remain in the Lower Yard, including soils with TPH below the selected remediation level of 2,975 ppm, a few locations with TPH levels marginally above that remediation level, and more substantially contaminated soils near the WSDOT storm drain line. It is also possible that one or more areas with elevated TPH concentrations have not yet been detected (as substantial portions of the southeast Lower Yard were not identified before excavations began).
No continuing pump-and-treat ground water remediation system has been included as part of the planned Lower Yard cleanup program. A system of 40 ground water monitoring wells, including both perimeter compliance wells and interior natural attenuation monitoring wells, has been established for ongoing sampling and analysis of ground water quality. A two-year ground water monitoring program is about one-third completed as of June 30, 2009. Through the first four rounds of sampling, a substantial fraction of the wells have shown TPH concentrations above the preliminary ground water cleanup levels (based on assumed TPH component types). Except for one well at the former slops pond location (MW-510), with very high and increasing TPH levels, the TPH concentrations are well below historic levels from mid-1990s sampling during the Remedial Investigation.
Data from the ground water monitoring program will be evaluated after Year 1 and Year 2 sampling are completed to determine if remaining TPH contamination will naturally attenuate and if cleanup levels are attained at the point of compliance wells (property boundary). If further cleanup actions are deemed necessary based on those evaluations, or if product is detected in the monitoring wells, a Feasibility Study will be prepared to evaluate alternative actions (e.g., further excavations or ground water treatment). If no further cleanup actions are needed, a Cleanup Action Plan documenting the Interim Actions as final cleanup actions will be prepared.
With further PPG support from Ecology, ECAC intends to continue to review all ground water monitoring data and evaluations and continue to inform the community and encourage citizen participation in the cleanup process.
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