Laserfiche WebLink
Califore Regional Water Quality trol Board <br /> Central Valley Region <br /> Katherine Hart,Chair <br /> CIFOPN P <br /> 11020 Sun Center Drive,#200,Rancho Cordova,California 95670-6114 <br /> Matthew Rodriquez (916)464-3291 •FAX(916)464-4645E Brown Jr. <br /> Secretaryfor http://www.waterboards.ca.gov/centralvalley v nor <br /> Environmental Protection RECE! <br /> 2011 <br /> yl NNIEK`A HEALTH <br /> 30 November 2011 E I ENVl E <br /> W. Michael Carroll Dennis Agar <br /> Solid Waste Division Deputy District Director <br /> San Joaquin County Dept. of Public Works California Department of Transportation <br /> P.O. Box 1810 P.O. Box 2048 <br /> Stockton, CA 95201 Stockton, CA 95201 <br /> REVIEW OF ADDENDUM TO FINAL CLOSURE PLAN AND POST CLOSURE <br /> MAINTENANCE PLAN (PLAN); WASTE DISCHARGE REQUIREMENTS ORDER R5-2001- <br /> 176 ( DR ORDER); SAN JOAQUIN COUNTY DEPARTMENT OF PUBLIC WORKS <br /> (DISCHARGER); CORRAL HOLLOW SANITARY LANDFILL (CHSL); SAN JOAQUIN <br /> COUNTY (COUNTY) <br /> Central Valley Water Board staff ("Board Staff") has reviewed the design of the proposed <br /> CHSL closure cap extension for compliance with California Code of Regulations (CCR) Title <br /> 27 requirements and has identified the following areas of concern: <br /> 1. The Plan proposes using a geosynthetic cover and no slope stability reports has been <br /> provided. <br /> Concerns: Title 27 Section 21090(a) states, "Designs having any slopes steeper than a <br /> horizontal to vertical ratio of three to one, or having a geosynthetic component(under <br /> (a)(2)], shall have these aspects of their design specifically supported in the slope stability <br /> report required under section 217500(5)." Therefore, a slope stability report is required. <br /> The responsible design engineer must consider slope failure due to insufficient resisting <br /> forces at the Geosynthetic Clay Liner (GCL) interfaces. The calculations should determine <br /> the shear and tensile forces generated in the GCL due to static and dynamic forces and <br /> whether the GCL is capable of transferring those forces without slippage at the GCL <br /> interfaces with the overlying/underlying material. <br /> 2. The Plan proposes using a one (1) foot minimum foundation layer below the GCL cover. <br /> Concerns: Title 27 Section 21090(a)(1) states, 'Closed landfills shall be provided with not <br /> less than two feet of appropriate materials as a foundation layer for the final cover. These <br /> materials may be soil, contaminated soil, incinerator ash, or other waste materials, <br /> provided that such materials have appropriate engineering properties to be used for a <br /> foundation layer. The foundation layer shall be compacted to the maximum density <br /> California Environmental Protection Agency <br /> �a Recycled Paper <br />