Laserfiche WebLink
POUIry <br />A THOMAS R. FLINN <br />DIRECTOR <br />C4i%FORa`P <br />THOMAS M. GAU <br />CHIEF DEPUTY DIRECTOR <br />MICHAEL SELLING <br />DEPUTY DIRECTOR <br />STEVEN WINKLER <br />DEPUTY DIRECTOR <br />ROGERJANES <br />BUSINESS ADMINISTRATOR <br />December 3, 2009 <br />Mr. John Moody <br />California Regional Water Quality Control Board <br />Central Valley Region <br />11020 Sun Center Drive, #200 <br />Rancho Cordova, California 95670 <br />R O. `BOX 1810 -1810 E. HAZELTON AVENUE <br />STOCKTON, CALIFORNIA 95201 <br />(209) 468-3000 FAX (209) 468-2999 <br />www.sjgov.org/pubworks <br />REcENED <br />tL0 12009 <br />E VI UWIyjtI PEW/VICE HEALTH <br />SUBJECT: PROPOSED VOC MONITORING POINTS; <br />NORTH COUNTY RECYCLING CENTER AND SANITARY LANDFILL <br />Dear Mr. Moody: <br />Thank you very much for offering to reduce the number of volatile organic compound (VOC) <br />sampling points at the North County Recycling Center and Sanitary Landfill, which will be <br />incorporated into the proposed Waste Discharge Requirements. <br />Although VOCs have not been confirmed in our groundwater since January 2003, 1 agree that <br />we should not ignore VOC concentrations entirely. A sudden increase in VOC concentrations <br />could indicate the need to consider preemptive action to prevent future groundwater impact. <br />Per your request, I suggest three points from which VOC samples would continue to be taken. <br />Based on our conversations, I understanding that the criteria for this selection (in order of <br />importance) are: <br />1. Monitoring to protect groundwater. To meet this objective, the lower probes of multiple - <br />probe wells are suggested. <br />2. Address concern regarding VOCs. To meet this criterion, wells that have historically <br />shown greater VOC concentration are suggested. <br />3. Provide representative monitoring. To meet this criterion, monitoring points would be <br />geographically dispersed. <br />4. Consider CO2 concentrations, which could affect groundwater alkalinity. <br />Based on the above criteria, I suggest the following probes be monitored in the future for VOC <br />concentrations (Figure 1 and Table 5) - <br />SG -2 (deep probe) <br />SG -3 (deep Probe) <br />SG -6 (single -probe well) <br />