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t CALIFORNIA REGIONAL WATERN L V BOARD - CENTRAL VALLEY REGION 3443 Routier Road, Suite A _911 Phone: (916) 361-5600 Sacramento, CA 95827-3098 VNVIRONMENTAL HEALTH ATSS Phone: 8-495-5600 TO: Kim Schwab FROM: William J. Marshall , Chief Closure Branch Waste Discharge to Land Unit California Integrated Waste Management Board �1 DATE: 12 July 1991 SIGNATURE: SUBJECT: HARVEY LANE LANDFILL CLOSURE PLAN - SAN JOAQUIN COUNTY We have reviewed the "Final Closure and Postclosure Maintenance Plan" (Closure Plan) for the Harney Lane Sanitary Landfill . The Plan does not meet the requirements of California Code of Regulations (CCR), Title 23, Chapter 15 (Chapter 15) and is not acceptable. We found major deficiencies with the proposed borrow material for the clay cap, the design criteria of the cap, and the Construction Quality Assurance (CQA) plan. We are seriously concerned that there is not enough clay soil on-site to construct the cap. In addition, the Construction Quality Assurance Plan does not address the special engineering requirements of the proposed borrow materials. Therefore, we recommend that the Closure Plan be denied pursuant to CCR, Title 14, Section 18271. Specific comments are as follows: 1. BORROW MATERIAL - The 1987 Kleinfelder Report (Attachment 2 of Appendix C of the Closure Plan) indicates that borrow soils for the clay barrier layer consist primarily of sandy silts to medium sands which are classified in the boring logs as SM, ML, SP, and SW using the Unified Soil Classification system (USCS). There is a minor amount of SC and CL materials present. However, these materials represent only about ten percent of the borrow material . Chapter 15, Section 2541 requires that soils used for clay liners (including caps) contain at least 30 percent material passing the No. 200 U.S. Standard sieve and be in the SC, CL or CH classes of the USCS. Therefore, the majority of the soils described by Kleinfelr in the borrow area do not meet the Chapter 15 requirements and are not acceptable. The Closure Plan states that the mixture of the minor amount of clay with other native soils will result in a permeability which meets the 1 x 10-6 cm/sec requirement. As proof that the mixture will meet the permeability requirement, the Closure Plan relies on the 1987 Kleinfelder report which states that a 10-6 cm/sec permeability can be achieved by proper blending of the soils. While proper blending may achieve the required permeability, there is no discussion of what proper blending is. Ata minimum, it would appear that proper blending would consist of removal of much of the highly permeability soils. We are concerned that there would not be a sufficient volume of the resulting acceptable mixture to complete the low permeability layer. No details are given concerning the process of mixing soils. We have seen clay soils mixed at a landfill liner site where the mixture was not acceptable due to the clay's tendency to form small clods when mixed with other soils. The inability of the contractor to evenly disperse the clay in other soils resulted