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Mr. Michael Carroll -6- 30 November 2011 <br /> 6. FCP Addendum Section 8.1 states that the "GCL will be placed over the Shell Oil pipeline <br /> in `break-away panels' to allow access to the pipeline with minimal damage to the barrier <br /> layer." <br /> Concerns: It is not clear what "break-away panels" means and how the design engineer or <br /> contractor plans to layout GCL panels to make this statement a functional reality. More <br /> information is needed on how this will work. Without a detailed panel layout during the <br /> design phase it is very difficult to determine if the proposed design will meet Title 27 <br /> requirements for maximum leakage through the CHSL cover. <br /> 7. There are miscellaneous errors in the GCL cover specification that should be corrected: <br /> a.The specification Table 02775-1 states that the GCL peel strength shall be 10 lbs/in. <br /> The proposed Bentomat ST or equivalent has a peel strength of 3.5 lbs/in. <br /> b.The specification states that GCL Permeability shall be 5x10-9 cm/sec per ASTM <br /> D5887. However, ASTM D5887-09 states that it should not be used to determine <br /> hydraulic conductivity "This test method does not provide a value of hydraulic <br /> conductivity. Although hydraulic conductivity can be determined in a manner similar <br /> to the method described in this test method, the thickness of the specimen is needed <br /> to calculate hydraulic conductivity. This test method does not include procedures for <br /> measuring the thickness of the GCL nor of the clay component within the GCL."The <br /> proper test method to measure permeability is ASTM D5084. <br /> c.A typographical error in Section 3.05.C.2.d (was "ASTM D5804", is "ASTM D5084"). <br /> Please provide written responses to the areas of concern noted above by 15 January 2012. If <br /> you have any questions, please call me at (916) 464-4815 or contact me via email at <br /> vkiain@waterboards.ca.gov. <br /> Vinoo Jain,`P.E. <br /> Water Resources Control Engineer <br /> Title 27 Permitting and Mines Unit <br /> Enclosure(s) <br /> 1.Cetco® GCL specification guidelines for Bentomat® ST <br /> cc: Gino Yetka, CalRecycle, Sacramento <br /> Robert McClellon, San Joaquin County Department of Environmental Health <br />