ARCHIVED REPORTS_XR0006820 - Laserfiche WebLink

Home Browse Search

(1 CAMBRIA Cambria temporarily stored the extracted groundwater onsite in a storage tank, and Onyx Industrial Services, Inc of Benicia, California transported the water via vacuum truck to the Shell refinery in Martinez, California for reclamation Data Collection and Sampling Cambria recorded data on standard forms We documented the static depth-to-water in onsite monitoring wells and distances between the extraction and monitoring points prior to beginning DPE Throughout the DPE test, Cambria measured the applied vacuum, airflow, volatile organic vapor concentration, and vacuum influence in nearby wells at 15- to 30-minute intervals Cambria collected samples of the extracted soil vapor several times during the interim remediation and collected groundwater samples from well VEW-2 prior to and after DPE Chemical Analyses STL-San Francisco, a State of California certified laboratory, analyzed all vapor and groundwater samples for TPHg, BTEX, and MTBE by EPA Method 8260B Health and Safety Plan Cambria prepared a site-specific Health and Safety Plan for the interim remediation activities and kept it onsite throughout the DPE test Results of DPE Interim Remediation The DPE vapor extraction data is summarized in Table 2 The DPE groundwater extraction data is summarized in Table 3 Table 4 presents the vacuum radius of influence data Laboratory analytical results are included in Appendix C Details of the DPE interim remediation are presented below June 21, 2004 Cambria began DPE from well VEW-2 at 11 45 on June 21 Groundwater was measured at 37 25 feet below the top of well casing (TOC) in VEW-2 prior to starting DPE Cambria personnel initially worked to dewater the well to a depth of approximately 45 fbg to expose the soils impacted with petroleum hydrocarbons Applied vacuum readings were measured at the wellhead The maximum wellhead vacuum achieved was 44 inches of water column-gauge {WC) The vapor extraction flow rate ranged from 10 0 to 66 3 standard cubic feet per minute (scfm) and averaged 39 9 scfm Cambria personnel observed a maximum vacuum influence of 0 07 and 0 02 inches WC in observation wells VEW-1 and MW-5, respectively The groundwater extraction rate ranged from 10 gallons per minute (gpm) to 1 2 gpm. A groundwater sample from extraction well VEW-2 was collected prior to implementing DPE on June 21, 2004 The sample contained 90,000 ppb TPHg and 1,900 ppb benzene MTBE was not 0854 6