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4.0 CORRECTIVE ACTION PLAN Based on the nature of the site impacts, and the results of the VET, soil vapor extraction is ' recommended as the most feasible and cost-effective interim corrective action option to remove TPH-as-Gasoline mass from soil beneath the site Test data indicate that vapor extraction has the ability to efficiently remove hydrocarbon mass from soil beneath the site This section outlines the proposed Corrective Action Plan (CAP) by providing preliminary design criteria and scheduling information relative to the design, permitting and operation of the proposed VES In addition, this section presents a site-specific VES layout, including proposed subsurface trench routes and the aboveground remediation equipment compound location ' 41 Preliminary Design Criteria A VET was performed to simulate future full-system site vapor extraction and obtain preliminary design criteria for a VES Data obtained from the VET indicate that a vapor extraction well flow rate of approximately 10 scfm per/well at a wellhead vacuum of approximately 70 inches of H2O can be achieved to create an ROI of approximately 20 feet and establish remedial coverage The preliminary design criteria for the VES is summarized below In addition, a VES Capture Zone and System Layout map for the subject site is depicted on Figure 9 ' Preliminary Design Criteria ' No of proposed vapor extraction wells 6 Well designations VW-1 S, VW-1 D, VW-2S, VW-2D, VW-3, VW-4 Extraction flow rate/per well = 10 scfm ' Minimum VES process capacity 60 scfm at 70" H2O Maximum VES process capacity 100 scfm a@ 100" H2O Estimated TPH-as-Gasoline vapor process concentration at start-up= 40,000 Mg/M3 VES TPH-as-Gasoline mass extraction rate at 60 scfm = 216 ppd 42 Off-Gas Treatment The estimated TPH-as-Gasoline extraction rate is 288 ppd at system start-up The San Joaquin Valley Unified Air Pollution Control Distnct (SJVUAPCD) requires the treatment of VES process flows that result in the extraction of greater than 1 ppd VES mass extraction rates of less that 1 ' ppd can be vented directly to the atmosphere, whereas potential emissions greater that 1 ppd require treatment to reduce the emission by a minimum of 95% prior to atmospheric discharge 15