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5-16 36.78, for the proposed 6 -inch diameter LCRS mainlines (see Appendix H for supporting calculations). 5.3.6 Landfill Gas Generation and Air Emissions Calculations Calculations regarding estimated gas generation and air emissions were conducted to properly design the gas control system. These calculations were made to provide for the construction of an efficient landfill gas extraction system. The landfill gas extraction system will be expanded as the landfill develops. Estimates of the landfill gas generated in each of the current (year 2000) in-place refuse prisms were added to the estimate of the landfill gas generation from the future combined fill areas. The landfill gas generation rate estimates were determined using the US EPA "Landfill Gas Emissions Model Version 2.0" (LandGEM) and EPA "Compilation of Air Pollution Emission Factors (AP -42)". In accordance with AP -42 ("Compilation of Air Pollutant Emission Factors", 5th Ed., EPA, 1997), a default k of 0.02/yr (the methane generation rate constant) is approved for use in the LandGEM program for arid areas like the Central Valley Region, which receive less than 25 inches of rain per year. A Lo value of 170 and 112.5 cubic meters of methane per megagram of refuse was also used in the LandGEM program for the in-place refuse at the landfill. From the compositional analysis of the material received at the Forward Landfill, a conservative estimate is that 31% of the accepted material is decomposable, whether it degrades easily or slowly. The landfill gas generation rates are presented in Appendix M. For design purposes, a collection efficiency of 85% was assumed for the proposed landfill gas extraction system. This collection efficiency is based upon the fact that although most of the combined site is or will be lined on the bottom and on the top, about 10% of the in- place refuse is not lined. The LandGEM program was also used for the Tier 1 Non -methane Organic Compound (NMOC) emission calculations as required in WWW 40 CFR 60, the New Source Performance Standards (HSPS). The Austin Road Landfill expansion plan states that the 50 megagram per year NMOC level has been achieved and that the landfill gas extraction system for that site will be installed to meet the HSPS requirements. The applicable Tier 1 NMOC Emission Study is currently under review. 5.4 Construction Quality Assurance 5.4.1 Introduction and Purpose A construction quality assurance (CQA) program provides definition of the materials and procedures to be used in the construction of landfill containment structures or groundwater protection systems, including a composite liner system, subsurface barriers, and final cover 0 system. A CQA program assures the regulatory agencies that the construction materials will be tested, installed, and monitored as specified in the design plans and specifications in Forward Landfill SWT Engineering Joint Technical Document - April 2014 z:\projects\allied waste\forward\five year permit rvw 2013\jtd-5 yr pr 2013\text\sec 5_final.doc