mWlWlTlllr,., <^9 ¦ ¦ WW7TSNUB/B0CCASES Yaucouve.n Washinaton 3EFA U.S. ENVIRONMENTAL PROTECTION AGENCY REGION 10 March 1999 Results from investigations conducted in January and February 1999, indicate that chromium contamination has migrated in the ground water as far as NE 30th Avenue. The investigations and cleanup efforts at the Boomsnub/BO C Gases site are intended to prevent the contamination in the alluvial aquifer from entering the Upper Troutdale Aquifer, the regional water supply, which lies below the alluvial aquifer. Recent Activities Near NE 30th Avenue The U.S. Environmental Protection Agency (EPA) installed 21 temporary monitoring wells to define the extent of the contamination in the alluvial aquifer. The alluvial aquifer is not used for the public water supply. Samples showed low levels of chromium, below the maximum contaminant level (MCL) for drinking water which is 100 parts per billion (ppb), as far west as NE 30th Avenue. However levels as high as 1440 ppb were found approximately 175 feet east of NE 30th (near IVIW-41, see Figure on page 3). In addition, trichloroethene (TCE) contamination as high as lOOppb was found near AMW-42. The MCL for TCE is 5 ppb. As a result of these high concentrations, EPA and BOC Gases have installed extraction wells at these two locations, both on Bonneville Power Administration property. EPA is currently installing a temporary extraction line to connect these wells to the rest of the ground water extraction network until the long-term pipeline is installed. BOC Gases is also installing three monitoring wells along NE 30th Avenue to help EPA determine how effectively the contamination is being controlled. PUBLIC MEETING EPA will attend a public meeting sponsored by the Clark County Citizen's Hazardous Waste Task Force scheduled for April 22,1999, from 7pm to 10pm at 8000 NE 52nd Court. At that meeting EPA will provide more detail on the activities described in this fact sheet. If you are interested in activities at the site or have questions, you are encouraged to attend this meeting. BOC Gases Removal Action (Operable Unit 2) BOC Gases will soon release results of the Site Evaluation conducted to determine if a significant source of TCE and other volatile organic compounds (VOCs) remain in the soil on the BOC Gases property. The results show that most of the VOCs contamination has moved from the soil into the groundwater and no soil removal appears necessary. However, action is necessary to control and contain ground water contamination which continues to migrate from beneath the BOC Gases property. BOC Gases is preparing a document called an Engineering Evaluation/Cost Analysis (EE/CA). The EE/CA analyzes the effectiveness and cost for two ground water cleanup alternatives to control and clean up contaminated groundwater beneath its ------- 2 oEFA = property. The two alternatives are: 1) air sparging with vapor extraction and, 2) in-well stripping with vapor extraction. When the EE/ CA becomes available in late spring 1999, a fact sheet and newspaper advertisement will announce a 30-day public comment period during which you can comment on the alternatives. EPA will select the cleanup alternative after reviewing and considering your comments. Site-Wide Groundwater (Operable Unit 3) and Boomsnub Soil Cleanup (Operable Unit 1) Information from EPA field investigations completed at the Boomsnub Soil Operable Unit (OU1) and the Site-Wide Groundwater Unit (OU3) is being compiled into a Remedial Investigation Report (RI) summarizing the findings. The updated information from these investigations is being used to help select the final cleanup actions for OU1 and OU3. The Remedial Investigation Report should be available for public review in April 1999. Work is well underway to identify a final cleanup action. EPA is evaluating three alternatives based on relative effectiveness, impiementabiiity, and costs. Cleanup options being considered for groundwater include: 1) a higher-capacity pump and treat system, 2) a "reactive barrier wall" that intercepts and treats contaminants flowing through ground water, and 3) "in-well stripping" technology that uses pumping wells but treats the ground water as it flows through the aquifer. A Feasibility Study Report (FS) summarizing this information is being prepared and will be available for public review before EPA asks for formal public comment on the cleanup alternatives. Boomsnub/BOC Gases March 1999 1 Background Boomsnub operated as a metal plating facility from 1967 until June 1994 at 7608 NE 47th Avenue. BOC Gases, located across the street from Boomsnub at 4758 NE 78th Street, is an active compressed gas manufacturing plant. For the purpose of environmental investigation, Boomsnub and BOC Gases are considered as one site because migrating contamination from both has resulted in a merged plume of contaminated ground water consisting of volatile organic compounds (VOCs) and chromium. In the summer and fall of 1994, the building where chrome plating took place at Boomsnub was demolished and removed from the site and 6,051 tons of chromium- contaminated soil were also removed. Elevated levels of chromium and VOCs were detected in ground water samples from wells both on and off the Boomsnub property. Ground-water monitoring wells in which elevated levels of VOCs were detected are located downgradient from BOC Gases. A new pump-and-treat system was designed and installed to more efficiently treat larger volumes of chromium and VOCs in ground water in order to stop the advancement of contamination. On April 25, 1995, EPA added the site to the National Priorities List. To facilitate the investigations and cleanup, the site was divided into three separate operable units in 1997. Although the contamination problems and the purpose of the investigations are specific for each unit, the investigation and decisions about the cleanup are being conducted concurrently. % ------- 3 &EFA Boomsnub/BOC Gases March 1999 ------- For More Information Documents pertaining to the cleanup of the Boomsnub/BOC Gases site are available for public review at the Fort Vancouver Regional Library, 1007 East Mill Plain Boulevard in Vancouver. For interested parties, EPA has made available groundwater data collected at the site from 1987 to 1998. This and other information about the Boomsnub/BOC Gases site can be found at: http://www.epa.gov/r10earth/datalib/superfund/boomsnub.htm If you have any questions, please call one of the following: Jean Baker, Community Relations Coordinator (206) 553-2587 Debbie Yamamoto, Project Manager (206) 553-7216 Peter Contreras, Project Manager (206) 553-6708 You may also call EPA toll-free at 1-800-424-4372 To ensure effective communication with everyone, additional services can be made available to persons with disabilities by contacting one of the numbers listed above. v- D United States EPA Region 10 Environmental Protection Community Relations and Outreach Agency 1200 Sixth Avenue, ECO-C81 Seattle, Washington 98101-1128 BULKRATE POSTAGE & FEES PAID U S EPA Permit No. G-35 SUPERFUND FACTSHEET BOOMSNUB/BOC CASES Vancouver, Washington ------- |