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KLEINFELDER landfill and liner projects, the addition of 15 percent Ione clay has been sufficient to meet regulatory permeability requirements of 1 x 10-6 cm/sec. As noted on Table 2-1, 20 percent Ione clay mixed with relatively clean sand, samples 3 did not meet project requirements. Except for sample 2, the addition of 15 percent Ione clay to SM & ML samples (1,4,6, & 7) met the minimum permeability requirements. However, the "cushion", or difference between laboratory permeability and that required in the field was not as high as desired. For this reason, we recommend that a minimum of 20 percent of Ione clay (by dry weight) be blended with the borrow materials. The recommended minimum degree of compaction is 95 percent of the maximum dry density as determined by the ASTM D1557 test procedure. It is recommended that the moisture content of the soil/clay mixture be at least 3 percent over optimum. We recognize that clean sand, similar to samples 3 and 8 may be encountered during the initial borrow excavation. Should this situation occur, these clean materials will be stockpiled for use elsewhere. Additional conformance testing of 80 percent silty sand combined with 20 percent clay from Superior Clay Products was performed by Kleinfelder. This mixture met laboratory permeability requirements and may be used as an alternate source. 2.5 CONSTRUCTION The SJDPW will hire a qualified earthwork contractor to assist with construction. SJDPW is currently accepting bids for closure construction. 2.6 CQA TESTING All CQA testing will be performed according to requirements of Section 17774, Title 14 as described in this document. As indicated in 2.1, SJDPW will carry out field and laboratory testing of the foundation and vegetative layers. Kleinfelder, as construction monitor will also perform a limited number of tests on these layers to verify the results obtained by SJDPW staff. Kleinfelder, as CQA Monitor, will perform all of the CQA testing of the barrier layer. Kleinfelder performed all CQA testing of the test pad previously constructed. A copy of our reports for the test pad results is included in Appendix D. The test methods and frequency for CQA testing are specified in Sections 7 and 8. CQA testing for correction of deficient construction is in Section 9. 2.7 ENGINEERING The SJDPW is the project manager and engineer for the project. It will provide engineering design plans, bench marks, and grade stakes to provide horizontal and vertical control of excavation and construction. The SJDPW will make modifications, as needed to these design plans during construction and provide as-built grading plans of the completed final cover. GSM.-MD 3EI94 Page 7 of 24 Copyright 1994 Kleinfelder, Inc.