ARCHIVED REPORTS_SEPARATE PHASE HYDROCARBON INVESTIGATION UNOCAL EXTRACTION WELL PILOT STUDY 2011

Home Browse Search

Stantec Report of Findings for the Waterfront Towers Separate Phase Hydrocarbon Investigation and Unocal Extraction Well Pilot Study Waterfront Towers Parking Lot March 4, 2011 HydropunchTM sampling device in soil boring SB-7. Results are summarized in SECOR's Additional Assessment Report and Work Plan for Additional Deep Groundwater Zone Assessment, dated July 29, 2004. The initial start-up of the DPE system was performed on August 2 and 3, 2004. Due to concerns associated with operating the DPE system during the removal of former pipelines found near the remediation system compound, the DPE system was temporarily deactivated on August 3, 2004. The remediation system conveyance lines and nearby sewer and water lines were also dismantled to accommodate the excavation of the abandoned former pipelines and surrounding petroleum hydrocarbon-impacted soil. The DPE system was reconnected, brought on-line on December 14, 2004, and operated during 1Q and 2A05. During the 1Q05, six horizontal SVE wells were installed beneath five apartment buildings within the Delta View Apartment complex. A final report documenting the pipeline abandonment, soil excavation, and horizontal SVE well installations was submitted to the CRWQCB-CVR and the Department of Toxic Substance Control (DTSC). This report is entitled Pipeline Removal, Abandonment, Soil Excavation, On-Site Horizontal SVE Well Installation, and Horizontal SVE Well Installation Beneath Delta View Apartments Report and Work Plan for Pipeline Removal, Abandonment, and Soil Excavation in Waterfront Towers Parking Lot, dated February 10, 2005, From March 21 through April 10, 2005, seven B-zone groundwater monitoring wells (MW-47 through MW-53), one groundwater monitoring well intended to be a C-zone well (MW-54), and one groundwater monitoring well intended to be a D-zone well (MW-55) were installed, and three Geoprobe soil borings (GP-1 through GP-3) were advanced. Results are summarized in SECOR's Additional Deep Groundwater Zone Assessment Report, dated May 25, 2005. From July 13 through July 15, 2005, 16 soil vapor points were installed to monitor soil gas concentrations over time and determine radius of influence of the previously installed SVE system. On July 19 and 20, 2005, baseline soil vapor samples were collected from 12 of the 16 vapor points. The SVE system was initiated on August 18, 2005 for select wells. The complete scope of work and results of the soil vapor well installations, SVE start-up, and soil vapor sampling were summarized in SECOR's Soil Vapor Well Installation and Soil Vapor Extraction Start-Up Report, dated November 30, 2005. From March 21 through March 23, 2006, additional assessment activities were conducted at the Site in accordance with the Work Plan submitted January 4, 2006 entitled Work Plan for Additional DPE Feasibility Testing and Expanded Remedial System Installation. Seven piezometers (PZ-1 through PZ-7) and one DPE well (DPE-13) were advanced for the purpose of conducting radius-of-influence analysis on several existing DPE wells. • Pilot testing on DPE wells was conducted between April 4 and April 26, 2006. A temporary aboveground extraction line was installed on DPE-13 and MW-40 as part of these pilot testing 2.7