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Environmental Consultants 4707 Greenleaf Circle 209 545-8490 and Contractors Suite F FAX 209 545-8391 Modesto,CA 95356 www.sesengineers.com July 6, 2010 File No. 07207049.00r— Mr. Don Litchfield J U 9 L W 0 Forward Landfill ENVSENT HEALTH 9999 South Austin Road E Ra i�1} Manteca, California 95335 PERMIT/SERVICES Subject: Second Quarter 2010, Perimeter Landfill Gas (LFG)Monitoring Probe and On-Site Structure Testing at the Forward Landfill,Manteca, California Dear Mr. Litchfield: This letter provides results of gas monitoring probes (GMP) and on-site structure testing for the second quarter of 2010 (April through June)performed by SCS Field Services (SCS). All testing, monitoring protocols and reporting were performed in general conformance with Title 27 California Code of Regulations (CCR)Article 6. Briefly,these regulations require that solid waste disposal site owners/operators implement LFG control or monitoring provisions to ensure that methane gas concentrations in soils at the property boundary do not exceed the lower explosive limit(LEL, or 5 percent by volume) and that interiors of on-site structures do not exceed 1.25 percent by volume in air. Below is a summary of our quarterly monitoring activities. SUMMARY AND CONCLUSIONS During this reporting period, no methane gas (the combustible component of LFG) in excess of the LEL was detected at any perimeter subsurface compliance GP probe location tested or in excess of 1.25 percent by volume in air at any interior locations of on-site structures,with the exceptions of LFG Monitoring Probe No..GP-11D, GP-11M, GP-11S, GP-12M and GP-12S (up to 65.1%by volume). SCS will continue to monitor these locations and adjust the wells in the surrounding area to bring the monitoring probes below regulatory compliance levels. These results indicate that at the time of our testing the subject site perimeter subsurface GP probes and interiors of on-site structures are in compliance with requirements of Title 27 CCR,with the exceptions noted above. SCS understands that the probe network is under review by the CIWMB to enable relocation of the probes to the property boundary. Also, during this reporting period, SCS performed testing of Temporary Subsurface Evaluation Monitoring Probe Nos. TGP-01 through TGP-39. Results of this testing indicated that up to 59.6 percent methane gas was detected at several of these monitoring locations. Note that these locations are for evaluation purposes only and are not compliance locations. YEARS