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File No. 20-1008-36 July 14, 1995 5.3 QUALITY CONTROL Assurance of the quality of construction requires that field tests be developed to identify appropriate construction procedures, equipment, and the material that is to be used. Based on these tests, the procedures and equipment may vary with changing fill material and site conditions. Assurance of the quality of construction includes advising the construction personnel of the necessity for exact fulfillment of design requirements and the consequences of inadequate workmanship. Construction personnel will also be made aware that requirements for compactive effort are more rigid when permeability and density criteria must be met than they are when density criteria alone must be met. Construction personnel should understand that compactive effort sufficient to produce passing dry density tests may not be sufficient to produce practical minimum attainable permeability for that density. Construction personnel should also understand that their prime purpose in constructing the compacted low permeability soil cover is to achieve minimal permeability, and to this end the acceptable clod size for the attainment of minimal permeability is significantly smaller than is acceptable to obtain adetuate dry density on other types of projects. Construction operations should comply with Section 24 of Caltrans Standard Specifications regarding particle size. This particle size is 60 percent soil passing the #4 sieve and 98 to 100 percent soil passing the 1-inch sieve. We note that the borrow soils may contain small quantities of rock materials. Maximum rock particle size should be 2 inches, with no more than 5 percent rock particles (rock retained on the #4 sieve) contained in the soil/rock mixture. Additionally, a minimum of 30 percent soil should pass the#200 sieve to meet state requirements. Throughout construction, the progress of the work will be monitored and measured to check that the work is proceeding as planned. Any changes to planned procedures must be approved and documented by the Engineer. In order to evaluate the construction equipment and methods to be used to construct the impermeable soil cover to the requirements of Chapter 15, Title 23, CCR, five trial low permeability cover sections (test pads)were constructed. GSM.-md CH/95 Page 19 of 31 July 14, 1995 20-1008-36(CQAC01) Copyright 1995,Kleinfelder,Inc.