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HOMAS R. FLINN P.O.BOX 1810-1810 E.HAZELTON AVENUE STOCKTON,CALIFORNIA 95201 DIRECTOR (209)468-3000 FAX(209)468-2999 www.sjgov.org/pubworks THOMAS M.GAU CHIEF DEPUTY DIRECTOR MICHAEL SELLING Wccl&g fbr YOU DEPUTY DIRECTOR nn r,=rr7�j STEVEN WINKLER W 11—'1\ rV�� DEPUTY DIRECTOR ROGER JANESLOIS BUSINESS ADMINISTRATOR June 8, 2010 jUN 1 4 ENVIRONMENT HEALTH Mr. Todd Del Frate PERMIT/SERVICES California Regional Water Quality Control Board Central Valley Region 11020 Sun Center Drive, #200 Rancho Cordova, California 95670-6114 SUBJECT: EVALUATION OF GROUNDWATER MONITORING WELL G-2 NORTH COUNTY RECYCLING CENTER AND SANITARY LANDFILL Dear Mr. Del Frate- Attached, please find a letter report from Shaw Environmental and Infrastructure addressing the condition and operational status of monitoring well G-2 at the North County Recycling Center and Sanitary Landfill. Groundwater samples have not been collected from this well since 1987 because it was not included in the Monitoring and Reporting Program. The County has monitored the depth to groundwater at that well regularly, and re-surveyed the elevation of this well in May as part of this investigation. The elevation of the well casing allows us to evaluate the relationship of this well to groundwater flow direction. Groundwater gradients apparently change during the year, as the gradients are quite small, especially compared to the seasonal change in groundwater elevation overall. Note that the groundwater contour lines are drawn at an interval of 0.2 feet. Based on these newly-drawn groundwater contours, well G-2 appears to be downgradient of the landfill.for much of the year. Unfortunately, this location is not accessible from County property during winter months, possibly preventing groundwater sampling in the first semester soon enough to include the data in our reports. Building an access road on our property to that location would require filling some vernal swales or vernal pool areas, the permitting process for which would be arduous. Therefore, our "workplan" for this well includes requesting permission to access well G-2 from the property west of our facility. If this permission is granted, then we will propose putting that well on our semi-annual monitoring schedule. If permission is not granted, we will propose to put this well on an annual monitoring schedule. In the meantime we have asked Shaw to assess the function of the pump now that the surface is dry and the well can be accessed from our property without significant risk to wetlands. Based on this assessment, we may replace the pump.