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Liner questions

October 1, 2011

From the GMA Techline RE: Liner questions I am designing a surface impoundment with interior side slopes of 1.5H:1V. This impoundment requires (per regulations) a geosynthetic clay liner (Bentomat DN or equivalent), 40-mil HDPE secondary liner, and 60-mil HDPE primary liner. A leak-detection system has been requested. The pit is small (approximately 500ft x 200ft) …

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Comparing GCLs

From the GMA Techline RE: GCLs I need some assistance in comparing two geosynthetic clay liners for a project where the specification gives a total bentonite mass required of 4500g/m2 and a target hydraulic conductivity of < 5 × 10-11. We have an option of a liner that far exceeds the requirement of the hydraulic …

NAUE opens new plant in Malaysia

May 20, 2011

Germany-based NAUE GmbH & Co. has opened a new geosynthetic clay liner (GCL) production center in Malaysia designed to serve the Asian and Oceanic markets, according to a May 19 press release from the company. “This is a significant move for NAUE,” said Thomas Knuffinke, one of the firm’s managing directors. “While the company has …

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Proven geosolutions for Florida landfill expansion

August 1, 2010

Introduction The combined efforts of industry experts make it possible to complete large, complex projects on time, on budget, and with the highest regard to quality. In 2009, the 62-acre expansion of the Sarasota Municipal Landfill was the state of Florida’s largest single landfill installation. In addition to adhering to state and federal regulations, Sarasota …

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GCLs and hydraulic equivalence

June 1, 2009

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 soil liner in terms of diffusive flow unless a natural …

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The effects of heat on Subtitle D composite liner systems

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 increase in hydraulic conductivity …

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Design strength for GCLs

By Timothy D. Stark Q: What design strength should be used for GCLs? A: If the GCL is not encapsulated between two geomembranes, the slope design should/must assume that the GCL will be fully hydrated at a low normal stress (e.g., 5–10 psi for a liner system). If the GCL will be encapsulated between two …

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GCL shrinkage: A possible solution

February 1, 2009

By Richard Thiel and Chris Thiel Introduction A potential industry-wide concern for GCL shrinkage was identified by Thiel and Richardson (2005) at the January 2005 Geo-Frontiers conference in Austin, Texas, based on observed problems at several sites worldwide. All of the known problems were for installations where an exposed geomembrane/GCL composite installation was left unballasted …

CETCO introduces new geosynthetic clay liner product

October 1, 2008

CETCO has introduced a new geosynthetic clay liner product that combines the benefits of its needlepunched GCLs with the pricing of its adhesive GCLs, according to a company press release. Bentomat 200R is manufactured with a 3.5oz-per-yd2 nonwoven polypropylene cap fabric that is needlepunched into a 3.2oz-per-yd2 woven polypropylene base. The new product contains 0.75lbs …

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Geomembrane thickness

April 1, 2008

From the GMA Techline Subject: Geomembrane thickness— We have been designing an ash pond for a thermal- electric plant, where we intend to use an HDPE geomembrane for the lining system. Can you recommend what thickness we should use for safety reasons, as our project is located near Halong Bay [in northeast Vietnam]? Do you …