Laserfiche WebLink
121 3/2011 Vinoo Jain RE FW contact info <br /> ( ��. < <br /> t <br /> As a regulatory agency we are required to make sure that landfill operators comply with Title 27 when <br /> closing their landfills. The covers need to meet or exceed the Title 27 requirement. <br /> On the surface it appears that the GCL is six(6) times superior to a compacted barrier soil. However, how <br /> does the GCL perform with less than 7 feet of cover soil?What is the minimum thickness of cover soil <br /> required over the GCL that yields an equivalent hydraulic conductivity of 1ft/year? (******Comments: <br /> Unfortunately, it is very difficult to for the current testing technology to perform testing at such low <br /> pressures. However, they can reduce the pressure some and they might be able to reduce the hydraulic <br /> pressure as well. I have attached John Allen on the email to see if can elaborate on how low he can go <br /> on effective pressure as well as hydraulic pressure.) <br /> Unless the manufacturer's of GCLs can readily provide that information it will be difficult for regulatory <br /> agencies to approve the use of GCLs for landfill covers. (*** Comments: We have been using GCL's on <br /> landfill caps for decades already. Please remember there are issues with compacted clay liners on caps. <br /> Such as dessication and cracks due to settlement. GCLs are far superior to CCLs in this regard. <br /> However, I would always use a composite liner system in a landfill cap not a gcl by itself. If you would like <br /> to discuss more feel free to contact me.) <br /> My Regards, <br /> Vinoo <br /> >>> Jimmy Youngblood <jyoungblood@gseworld.com> 12/7/2011 2:20 PM >>> <br /> Vinoo, <br /> The properties on the datasheet are directly related to the effective stress of the ASTM which is 5 psi. <br /> We have not performed testing at lower effective stresses that you mention below. I do not think it is <br /> possible with current testing equipment. I would suggest talking with TRI laboratories to see if they have <br /> ever performed testing at such low effective stress. Earthen cover thickness would depend on the density <br /> of the cover soil, but if it is 100 Ib/ft3 then approximately 7 feet. <br /> -----Original Message----- <br /> From: Vinoo Jain [mailto:vkjain@waterboards.ca.gov] <br /> Sent: Wednesday, December 07, 2011 3:40 PM <br /> To: Jimmy Youngblood <br /> Cc: Miguel Garcia <br />