VOCs in groundwater @ Bevatron site, LBNL/Berkeley

[VOCs - volatile organic compounds - leeching into groundwater at Bevatron site, Berkeley.]

Department of Toxic Substances Control Fact Sheet, May 2013

Lawrence Berkeley National Laboratory Interim Corrective Measures Workplan Available for Public Comment

Background: The California Department of Toxic Substance Control (DTSC) has prepared this fact sheet to inform the community about the 30-Day Public Comment Period for the Interim Corrective Measures Workplan to Control the Migration of Contaminated Groundwater at the Bevatron Demolition Project Site (Site) located at One Cyclotron Road in Berkeley, California 94720-8272, Alameda County, California. The purpose of this Work Plan is to provide the rationale and establish the requirements for constructing and operating an Interim Corrective Measure (ICM) in the Vacuum Pump Room area of the former Bevatron Complex at the Lawrence Berkeley National Laboratory (LBNL). The main LBNL site is located on 202 acres of land within the hillside area, east of the University of California, Berkeley campus. In 1993, DTSC issued a Hazardous Waste Facility Permit to LBNL. As a condition of that permit, LBNL is required to investigate and address all historical releases of hazardous waste and chemicals that may have occurred at the site in accordance with RCRA corrective action process requirements. Investigation of the historical releases, determination of which releases require corrective action, and evaluation/recommendation of proposed remedies have been completed. In August 2005, DTSC approved LBNL's Corrective Measure Study, which provided remedies for all contamination known at that time to require corrective action.
Building 51, which housed the Bevatron, occupied approximately 2.25 acres in the west-central part of the LBNL Site. During its operation from 1954 until 1993, the Bevatron was among the world's leading particle accelerators. The Building 51 and Bevatron Demolition Project, which began in 2010, consisted of the demolition, deactivation, and disposal of the Building 51 structure and contents; including the shallow foundations, shield blocks, and the Bevatron accelerator housed within the building. Following demolition, the site was backfilled to grade with clean soil. Between September 2010 and April 2011, LBNL conducted a preliminary investigation of potential subsurface contamination beneath the Building 51 Demolition Project area. During this preliminary investigation, relatively high concentrations of volatile organic compounds (VOCs) were detected in the soil and groundwater under the former Vacuum Pump Room area of Building 51. The project area is primarily referred to as Building 51 in the workplan, but is also referred to as the Bevatron Complex or simply as the Bevatron. Building 51 included Building 51A, an integral addition. Except for the area overlying the former Vacuum Pump Room, the project area has been paved to provide parking, and is not currently scheduled for development. Objective of the ICM The objective of the ICM is to control the migration of contaminated groundwater from the former Vacuum Pump Room area of the Bevatron. The groundwater level in the eastern end of the backfilled Bevatron Air Duct shafts has risen several feet since demolition of the Bevatron was completed. This groundwater is contaminated with trichloroethylene (TCE), cis-1,2-dichloroethene (DCE), 1,1,1-trichloroethane (TCA), and vinyl chloride. The results indicate that since demolition of the Bevatron and backfilling of the Air Duct shafts, contaminated groundwater has migrated from the former Vacuum Pump Room area into the clean Air Duct backfill.

Summary of Existing Conditions: The description of existing conditions in the Vacuum Pump Room area is based on environmental investigations conducted between September 2010 and December 2011. The investigations included soil vapor, soil, and groundwater sampling. The results of these investigations are reported in detailing the Report of Environmental Investigations in the Building 51A and Vacuum Pump Room Areas for the Building 51 and Bevatron Demolition Project and are summarized in the following subsections. Potential Risk to Human Health Currently, there is no significant risk to human health associated with VOC contamination detected in the former Vacuum Pump Room area. The potential exposure pathways relevant to human health risks are inhalation due to vapor intrusion into indoor air and/or direct contact with contaminated soil. Groundwater at LBNL is not used for drinking, irrigation, or other industrial or domestic purposes. VOCs have been detected in soil vapor and groundwater at concentrations well above screening levels for potential risk to potential future indoor workers via the vapor intrusion pathway. However, there is no risk to current workers since this pathway is not complete because there are no buildings overlying the areas where the screening levels are exceeded. Concentrations of VOCs in the soil exceed screening levels for direct contact by outdoor workers in two limited locations in the former Vacuum Pump Room area. Both of these locations have been posted with warning signs requiring Hazardous Waste Operation (HAZWOPER) training for any worker handling soil in the posted area. Potential Risk to the Environment Since demolition of the Bevatron and backfilling of the Air Duct shafts, contaminated groundwater has been migrating from the former Vacuum Pump Room area into the clean Air Duct backfill. Although a replacement subdrain system that was installed under the central Bevatron area during the demolition project may capture the migrating groundwat-er, the potential impact to the clean Air Duct backfill before that barrier is reached is considered to be an imminent threat to the environment, and is therefore the subject of this ICM. System Design The ICM will comprise construction of an extraction well in the former Vacuum Pump Room area, extraction of groundwater from the new extraction well and existing observation well, and treatment of the extracted groundwater at the existing Building 51 Motor Generator Room Treatment System. This treatment system was approved as part of the November 2005 Corrective Measures Implementation Workplan. Extraction Well A 2-foot diameter groundwater extraction well will be drilled to a depth of 20 feet (approximately 10 feet beneath the Air Duct floor) inside the southern part of the former Vacuum Pump Room upgradient from the Air Duct shafts. Three contiguous 2-foot diameter borings will be drilled immediately adjacent to the extraction well and will be backfilled with drain rock to enhance the yield of the extraction well. The multiple large-diameter borings are required for groundwater extraction due to the low hydraulic conductivity of the artificial fill and bedrock beneath the former Vacuum Pump Room location.

Informational Repositories: Department of Toxic Substances Control Berkeley File Room 700 Heinz Avenue Berkeley, CA 94704 (510) 540-3800 Call for Appointment Berkeley Public Library 2090 Kittredge Street Berkeley, CA 94710 (510) 981-6100 Call for hours and days of operation Envirostor Link To view electronic versions of the ICM Work-plan, visit DTSC's Envirostor website: http:// http://www.envirostor.dtsc.ca.gov/public Enter "Berkeley" in the city section and select "Lawrence Berkeley National Laboratory" from the alphabetical list of sites.
For More Information Jacinto Soto DTSC Project Manager 700 Heinz Avenue Berkeley, CA 94710 (510) 540-3842 Jacinto.Soto [at] dtsc.ca.gov Richard A Perry DTSC Public Participation Specialist 700 Heinz Avenue Berkeley, CA 94710 (510) 540-3910 Richard.Perry [at] dtsc.ca.gov Notice to the Hearing Impaired TDD users can use the California Relay Service at (888) 877-5378 and ask to speak with Richard Perry at (510) 540-3910. Annuncio Si prefiere hablar con alguien en espa¤ol acera de ‚sta informaci¢n, favor de llamar a Jacinto Soto, Departamento de Control de Substancias T¢xicas, al n£mero de tel‚fono (510) 540-3842.
Public Comment Period We encourage you to review the Draft ICM Workplan and proposed Negative Declaration. DTSC is holding a 30-day public comment period for the ICM beginning May 7, 2013. All comments must be postmarked by June 7, 2013. All e-mailed comments must be received no later than 5:00 pm on that same day. Please submit written comments to: Jacinto Soto DTSC Project Manager 700 Heinz Avenue Berkeley, CA 94710 Call (510) 540-3842 or email Jacinto.Soto [at] dtsc.ca.gov OT #4856086; May 14, 2013