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5-7 local climatological data, soil data specific to existing on-site materials that are available for final cover construction and vegetative conditions typical of the area near the landfill. Based on the GLA alternative final cover report (Appendix 1), it was determined that a four - foot thick monolithic alternative final cover section composed of on-site soils will satisfy the regulatory requirements for an alternative final cover as defined in 27 CCR. More specifically, the modeling completed as included in GLA's report indicates that the alternative final cover system constructed using available on-site soils would afford superior protection against water quality impairment. A traditional barrier layer is not proposed for the alternative final cover design. Site-specific conditions at the Forward Landfill rendered a performance criteria based on annual surface water infiltration through the proposed alternative final cover. Based on four years of moisture monitoring performance data submitted to the Central Valley RWQCB, the alternative final cover was approved and the RWQCB determined that the alternative ET final cover met the performance standards of 27 CCR, Section 21090 (see RWQCB letter [dated September 2010] in Appendix 1). Therefore, the alternative final cover design for the Forward Landfill will consist of a total of a four -foot thick layer of select soil material may be placed to comprise the foundation soil layer and the upper monolithic cover layer. Atypical cross-section of the proposed alternative final cover system is shown on Drawing 5. 18 The alternative final cover configuration has been designed to: ♦ Ensure the containment of waste materials; ♦ Minimize the infiltration of water from rain and provide a vegetative cover of native shrubs and grasses; ♦ Prevent exposure of people and animals to waste; ♦ Limit landfill gas emissions; ♦ Minimize odor; ♦ Control fires; and ♦ Provide for an aesthetically pleasing appearance. The final cover was designed by a certified engineering geologist in accordance with State and Federal regulations and will be constructed in accordance with the Final Closure/Post- Closure Maintenance Plan. 5.2.4.3 Soil Availability Materials for construction of the final cover will be obtained from on-site soil borrow areas. 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