Geomembrane leakage rates

From the GMA Techline

RE: Geomembrane leakage rates
I’m wondering if you can help me find an average value and range of values for geomembrane cover leakage rates (in gallons/acre/day) as it relates to waste rock stockpiles or covers for solid waste disposal. I reviewed the Geosynthetic Institute website but did not find any references to leakage rates.

(Sara | Minnesota)

Reply: We don’t have data for covers but we do have for liners. These liners are all double-lined and the leak detection system data is available. It is given for a geomembrane alone, a GM/CCL, and a GM/GCL. There is data for 270 cells and we will send the response curves [to you].

The three trends are exponentially decreasing over time with high values for the GM alone ranging from 40 to 8 gpad and low values for the GM/GC ranging from 10 to nil gpad. [This] data is also available in my book, Designing With Geosynthetics.

This data is for municipal solid waste (MSW) landfills; waste rock might be higher depending on the cushioning and subgrade status and might be lower due to the lack of confining stresses…

Bob Koerner | GMA Techline