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Jim Crandell -2 - 15 February 2005 Process Water Treatment and Reuse Evaluation Workplan The Process Water Treatment and Reuse Evaluation Workplan almost exclusively considers the biologically treatable waste constituents but FDS should be the focus of the investigation. Because FDS constituents are not treated biologically, nor are they degraded, transformed, or immobilized when applied to land. Source control is the best method to achieve the desired result of groundwater quality protection. Other available means might include further treatment of wastewater with methods that reduce the concentration of FDS or separation of high salinity wastestreams from the pond/land application system. Groundwater Characterization Workplan The Groundwater Characterization Workplan presents an investigation that will not resolve central questions related to the storage and application of wastewater to land. In addition, some of the data collected regarding off-site potential sources is unlikely to result in a better understanding of site conditions. For example, investigation of off-site sources that are downgradient of the winery or located south of the Mokelumne River are unlikely to be relevant to the investigation at the winery. If the on- site investigation indicates contaminants are present in the upgradient wells, then it may be prudent to expand the investigation to alternative sources. To date, upgradient wells have not contained elevated concentrations of FDS. The proposed on-site investigation consists of continued monitoring of groundwater quality and elevation in the on-site wells, installation of a stream gauge, and nine Cone Penetrometer Tests (CPT) with grab groundwater sampling. I have the following comments regarding the on-site investigation: • It is recommended that the Mokelumne River be sampled to document its quality. The samples should be analyzed for the constituents of concern in groundwater. • Installation of a gauge that allows measurement of the wastewater pond elevation is recommended. Review of chemical trends in Figures 7 and 8 indicates during the late fall and winter, wastewater pond elevation may be high enough to control groundwater flow direction. • The use of existing production wells as monitoring wells is generally discouraged because they are screened in lower aquifers and their construction generally is not suitable for use in monitoring specific groundwater zones. • The CPT/Hydropunch study is proposed in areas that are downgradient of the wastewater ponds or land application areas. To investigate groundwater quality trends in areas without wastewater ponds, consider performing some sampling in areas not suspected to be impacted by waste application or storage to determine if the Mokelumne River is contributing low TDS water and an increasing trend of TDS is observed away from the river in areas where no wastewater impact is suspected. • Section 4.7.2 states an initial depth of 75 feet will be probedwith the CPT to investigate both "perched groundwater and the first water bearing zone." The section also describes using the CPT to evaluate the groundwater gradient. Please describe how groundwater elevations will be measured. W1SuplpptiCf DIoaquffiR Mor vTCnMd19 Feb 05.doc