Fixing an exposed landfill cover

June 1, 2009  |  Products

By Timothy D. Stark Q: The following photo shows a landfill cover with a gray material exposed. Is this good? If not, what should be done? A: A close-up of the gray material indicates that it is the geomembrane that is part of the final cover system for this landfill. This is not good and … <…
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Characterization of textured geomembranes predictive of interface properties

June 1, 2009  |  Products

Currently under development is a new application of technology for textured geomembrane sheet characterization. By Boyd Ramsey and Jimmy Youngblood Introduction Currently under development is a new application of technology for textured geomembrane sheet characterization. We believe this method of c…
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GCLs and hydraulic equivalence

June 1, 2009  |  Products

By Timothy D. Stark Q: Are GCLs hydraulically equivalent to a compacted low permeability soil liner? A: A good, but difficult, question. GCLs are hydraulically equivalent to low permeability soil liner in terms of advective flow. However, GCLs are not hydraulically equivalent to low permeability soi…
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The effects of heat on Subtitle D composite liner systems

June 1, 2009  |  Products

By Timothy D. Stark Q: What effect does heat have on a Subtitle D composite liner system? A: Heat can have many detrimental effects on a Subtitle D composite liner system. For example, heat can adversely affect the compacted low permeability soil liner by reducing its moisture content, leading to an…
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Prefabricated bituminous geomembrane: A candidate for exposed geomembrane caps

April 1, 2009  |  Products

By Ian Peggs Landfill caps prevent incident precipitation from becoming leachate that has to be treated, contain landfill gas that can be used to generate electricity, and prevent odors that annoy neighbors. Typically, geomembrane caps are covered with soil and vegetation for appearance and for the …
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Geocomposite drainage

April 1, 2009  |  Products

From the GMA Techline Subject: Geocomposite drainage — Canadian landfills apparently have not been allowed to use geocomposite drainage materials in lieu of 2 feet of gravel because they have to prove it will not clog for a period of up to 100 years. Have you studied this in the various geocom…
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Flash point

October 1, 2008  |  Products

From the GMA Techline Subject: Flash point— A contractor is proposing installation of a PVC geocomposite in a tunnel as a lining. The California Code of Regulations stipulates the nonuse of materials with a flash point of 100°F or less. Would any of the cements/sealers used in installation…
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Rub sheets

October 1, 2008  |  Products

From the GMA Techline Subject: Rub sheets— What kind of developments are going on these days with rub sheets in leachate sumps with sideslope risers? I’ve seen multiple sheets of geomembrane, but I am more familiar with thick (100- and 120-mil) stock sheet material. Also, what do you thi…
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Geomembrane costs

October 1, 2008  |  Products

From the GMA Techline Subject: Geomembrane costs — What is the average cost in U.S. dollars, for installation only, of 10,000m2 and 100,000m2 of PVC membrane and HDPE membrane? (Lindo, Louisiana) Reply: I can’t give you an answer, since costs vary with the thickness of the geomembrane, t…
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How long will my liner last?

October 1, 2008  |  Products

What is the remaining service life of my HDPE geomembrane? By Ian D. Peggs, P.E., P.Eng., Ph.D. Introduction In his keynote lecture at the GeoAmericas-2008 conference last March, Dr. Robert Koerner (et al., 2008) of the Geosynthetic Institute (GSI) reported the ongoing Geosynthetic Research Institut…
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