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n Mr. Greg Basso -3- 11 July 1989 Mr. Tom Woodward method by which compacted soil will be replaced over the transfer pipes in the trenches, without jeopardizing the pipes' structural integrity, also needs to be described in the design report. Drawings 5 and 6 show 2 transfer pipes in each trench in the northern portion of the WMU. The plans do not specify whether soil will be compacted between these pipes. Precipitation and drainage controls required by Section 2546 of Subchapter 15 are not discussed in the design report. This deficiency needs to be corrected. The design report does not address water quality monitoring for the proposed unit as required by Article 5 of Subchapter 15. Ground water and vadose zone monitoring need to be discussed in the design report. The report states that monitoring wells 5 and 9 will be abandoned to construct Phase II of D89. These wells must be properly abandoned as specified in the facility's WDRs and approved by the San Joaquin Local Health District. A CQA plan for soil liner construction was submitted as part of the WMU D89 design plan. The proposed CQA plan includes the use of a test pad which will be constructed to minimum standards with respect to physical properties, compactive effort and moisture content. Both physical and permeability tests of the test pad will provide bench marks by which the WMU liner can be evaluated in terms of construction methods and physical properties to ensure low permeability. We concur with the conceptual use of the test pad but suggest that several improvements be made in the CQA plan. The CQA plan should be rewritten as a stand-alone document which can be used for the current WMU as well as future WMU construction projects. You should not need to reinvent, and we should not have to review, a construction quality assur- ance program every year. A major improvement to the CQA plan would be the addition of a table which specifies the items to be tested, the test methods and the testing frequency. The test items should include the soil borrow source(s), the test pad, the soil liner, and granular drainage material. The proposed test methods should include ASTM or other designations where appropriate. The testing frequency should be expressed in terms of cubic yards for borrow material and number of tests per acre per lift (test/acre/lift) for compacted soil liner