ARCHIVED REPORTS_2010 - Laserfiche WebLink

Home Browse Search

Environmental Consultants 4707 Greenleaf Circle 209 545-8490 and Contractors Suite F FAX 209 545-8391 s Modesto, CA 95356 www.scsfieldservices.com April 9, 2010 RECE8VED File No. 07207048.00 JUN 2010 Mr. Don Litchfield ENVIROWENT HEALTH Forward Landfill PERMIT/SERVICES 9999 S.Austin Road Manteca, California 95336 Subject: Operation, Monitoring, and Maintenance of the Landfill Gas (LFG)Migration Control Facilities at the Forward/Austin Landfill,Manteca, California Dear Mr. Litchfield: This letter provides a status report on the operation,monitoring, and maintenance (O&M)work performed by SCS Field Services (SCS)on the subject system. All activities were performed in accordance with our approved proposal dated August 14,2007. Below is a summary of O&M efforts during the period of March 1 through 31, 2010. OPERATION STATUS AND CONCLUSIONS As of the dates of our testing,the LFG control facilities appeared to be operating satisfactorily and generally meeting the operational criteria. During the month of March 2010,no methane gas concentrations above the LEL were detected at any compliance Perimeter Monitoring Probe tested by SCS,with the exceptions of LFG Monitoring Probe Nos. GP-11M, GP-11 S and GP-12S (up to 63.9%by volume). All LFG extraction wells were observed to be receiving adequate vacuum, for compliance with the Title V permit and several were adjusted during this monitoring period. BACKGROUND As you know,the Forward/Austin Landfill site is an active organic refuse disposal site. By way of background, organic materials buried in a landfill decompose anaerobically(in the absence of oxygen)producing a combustible gas,which contains approximately 50 to 60 percent methane, 40 to 50 percent carbon dioxide, and trace amounts of various other gases, some of which are odorous. The Forward/Austin property contains a system to control the combustible gases generated in the landfill. The gases produced in a landfill will either vent vertically to the atmosphere or migrate horizontally through subsurface soil to locations on adjacent properties. If the soil surrounding a landfill consists of permeable materials,there is a greater likelihood that the LFG will migrate to off-site locations.