UAR/PROP 65 FILE 3 - Laserfiche WebLink

Home Browse Search

CONESTO3AmROVERS Mr, Michael Infuina & ASSOCIATES November 26, 2008 • Injection Event Monitoring: During injection events, visual monitoring of the injection wells will be performed throughout the event. Additionally, field parameters of DO, temperature, pH, ORP, oxygen levels (%OZ) at the well head, volatile organic compound (VOC) vapor levels at the well head, and groundwater depth will be collected from the nearby monitoring wells MW-5R, MW-18, and RW-lA. • Field Parameter Monitoring Events: Field parameter monitoring will be conducted every two weeks following the first injection event and will consist of monitoring field parameters for groundwater depth, DO, temperature, pH, ORP, well head %OZ, and well head VOC vapor from the injection wells and nearby monitoring wells MW-5R, MW48, and RW4A. • Monthly Sampling Events: Monthly sampling will be performed beginning one month after the first injection event, and scheduled to occur just prior to any subsequent injection event. Samples will be collected from all injection wells and nearby monitoring . wells MW-5R, MW48, and RW-lA, These samples will be analyzed for sulfate, TPHg, BTEX, MTBE, and TBA. Based on the baseline samples and bench-test treatability study results, samples may also be analyzed for metals such as arsenic, chromium, and bromide. • Quarterly Sampling Events: Monitoring will take place quarterly for one year after the final injection event. DO, pH, and ORP will be field measured and samples will be analyzed for sulfate, TPHg, BTEX, MTBE, and TBA. Laboratory Analyses: Water samples will be analyzed by a State-certified laboratory. Discharge and Monitoring Reports: CRA will submit quarterly discharge and monitoring reports consistent with the requirements of the Central Valley Region's California Regional Water Quality Control Board Order No. R5-2008-0149. The quarterly reports will include all injection and monitoring data as well as an evaluation of ISCO effectiveness. The quarterly injection of sodium persulfate will be halted if: • The remedial objectives have been met; • The concentrations in monitoring wells MW-5R, MW-18, and RW4A show little or no change after the first four injection events; or • Eight quarterly injection events have been completed. MONITORED NATURAL ATTENUATION Hydrocarbons naturally degrade in the subsurface through several processes including biodegradation, adsorption, chemical reactions, volatilization, and dilution with groundwater. 240783 7 Worldwide Engineering, Environmental, Construction, and IT Services