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San Joaquin County Project Description monitored with a hand-held combustible gas detector. The landfill facility is presently in compliance. VOC detections in groundwater are sporadic and inconsistent,often due to the low detection limits for these compounds and the potential for trace concentrations of contamination in the laboratory environment. However,LFG has apparently affected groundwater for a short time in the past. In July 2002, one VOC(reactive organic gas)was confirmed at one groundwater monitoring well. No other VOCs have been detected since that time,except for sporadic trace detections. The County installed an LFG collection and treatment system in 2005 to control LFG migration and alleviate possible concerns for groundwater impacts. The WDRs issued by the Central Valley Water Board also require monitoring the soil within the landfill for VOCs. Four additional wells,along with the perimeter migration monitoring wells,are monitored to satisfy that requirement. VOCs were found at many of the soil gas wells;however,the presence of VOCs in the �soil gas does not appear to impair the waters of the State. Consequently,releases of LFG as a result of this project would be considered less than significant,and no additional mitigation would be required. The NCRC&SL is subject to Code of Federal Regulations(CFR)Part 40,which limits the emissions of VOCs to 55 tons per year. Recent estimates,based on samples of LFG taken at the landfill facility,indicate that the VOC emissions are approximately one-half this limit;therefore,present air quality regulations do not require an LFG collection and treatment system. However,the installation of an LFG collection and treatment system will greatly reduce the VOC emissions, decreasing them farther below the regulatory limit. As the refuse in the landfill increases,the potential to emit VOCs will gradually increase;however,the LFG collection and treatment system would be expanded in accordance with air quality regulations into new refuse placement areas, 1 ensuring the control of LFG emissions from refuse placed in the vertical expansion. Odors must be controlled. For the purpose of this evaluation,an odor nuisance is indicated by complaints filed by nearby residents or others outside the landfill property boundary. Normal landfill operations are not expected to be odor-free, as some odors will be detectable at or near the refuse fill;however,present odor control procedures are successful, as indicated by a lack of offsite odor complaints filed. Presently,odors are controlled by the daily placement of soil over the refuse. Measures to control LFG would continue under the proposed permit revision. In addition,the installation of a LFG collection and treatment system would further decrease the odor nuisance potential. Increasing the maximum permitted daily disposal tonnage would allow the placement of more refuse;this could result in a gradual increase of LFG,which Notice of Preparation for the June 2006 North County Recycling Center and Sanitary Landfill 1-8 Jas os307.os Permit Revision