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ARCADIS Ms. Lisa Medina June 22, 2012 5.2.1 Phase 1: Vacuum Step Test The first phase of the pilot test will be a vacuum step test(the step test)that will be conducted over a short period of time(no more than a few hours). During the step test, vacuum will be applied to the extraction well in a series of pre-determined and increasing rates with a constant vacuum at each vacuum rate for a short time period. At each incremental rate, the vacuum at the wellhead will be allowed to stabilize and the influent flow rate and influent PID reading will be recorded. The step test will be performed until the maximum sustainable formation vacuum is achieved, the maximum blower vacuum has been applied, or the vacuum causes upwelling and occlusion of the well screen. Each observation location will also be measured for induced vacuum to establish the extent of the vacuum ROI with varying applied extraction vacuum levels. The maximum vacuum attained during the step test will be used to conduct the remaining phase of the pilot test. 5.2.2 Phase 2: Constant Rate SVE Test The second phase of the pilot test will be a constant rate test using the selected vacuum as established during the step test. The purpose of constant rate test is to both establish the extraction well ROI at the selected vacuum and to estimate the initial volatile organic compound (VOC) concentrations at the extraction well head.As such, the constant rate test will serve as the basis for the design of the SVE network and the SVE off-gas treatment system. During the course of the test, applied vacuum at the extraction well and induced vacuum at the observation locations will be monitored and recorded at regular intervals with vacuum gauges attached to each wellhead. Upon completion of the constant rate test, the data will be evaluated and the achievable ROI selected. Performance monitoring of the SVE system will also be conducted on both the influent and effluent streams of the system during the constant rate test. Individual extraction wellheads and the system influent stream will be monitored for air flow rate, temperature, and VOC concentration at regular intervals. The data will be used to establish applied vacuum versus soil vapor flow rate versus time and mass removal rate versus time. The effluent stream will be monitored for VOC concentrations to verify treatment of the off-gas vapors is effective. Page: G Vyrgac WBRCPA]595'fi Cef v WIWw RaWSVE pOM�tl WanlCP W5�120522BP SVE NU TM WP dz 7/9