Agmt02 Harding ESE - Laserfiche WebLink

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November 5, 2001 53636.001 Mr. Peter Ingram City of Redwood City Page 4 information suggests that possible dischargers to the sewer include Roy's Cleaners, the former Davies auto dealership, and other former or current businesses along ECR between Jefferson and James Avenues. August 2000 Meeting with SFRWQCB The purpose of the August 2000 meeting with SFRWQCB staff was to (1) present the findings of SCI's February 2000 investigation; (2) discuss SFRWQCB's and the City's views on potentially responsible parties with respect to the HVOCs in groundwater; and (3) propose a phased, risk-based, management approach for proceeding with further steps to characterize the extent of the solvent plume, and evaluate what remediation measures, if any, may be necessary. SFRWQCB staff agreed in concept with the proposed approach and generalized scope of work discussed at the meeting, which included the following initial steps: (1) Further investigation activities to better define the subsurface stratigraphy and lateral/vertical extent of HVOCs, and (2) Preliminary evaluation of potential migration pathways and sensitive receptors in order to begin to assess the potential human health and ecological risks posed by the HVOC plume. APPROACH As previously discussed with the City and SFRWQCB staff, Harding ESE proposes to group site investigation activities into several phases of work, based on such factors as information needs and key decisions points. Based on this approach, we have group proposed and/or anticipated tasks into three phases, as summarized below. Phase 1 - Environmental Site Characterization · Delineation of subsurface soil stratigraphy, · Evaluation of lateral and vertical distribution of HVOCs in groundwater, soil, and soil-gas, and · Identification of potentially complete pathways and sensitive receptors with respect to possible HVOC exposure. Project deliverables associated with this phase of work will include a Project Report prepared upon completion of the Phase 1 tasks. The project report will present a lateral and vertical characterization of site stratigraphy, and discuss the distribution of HVOCs in the subsurface. It will also recommend the locations and construction details of proposed groundwater monitoring wells, and a Site Conceptual Model for conducting future risk assessment activities.