Readers question ‘zero leaks’

October 1, 2017

To the editor: Efforts toward achieving zero leaks in a waste containment system (“Achieving Zero Leaks on a Budget” in the June/July issue of Geosynthetics) are certainly laudable. Authors Gilson-Beck and Toepfer do a good job of explaining how electrical leak detection surveys can minimize leaks in a geomembrane liner system at the end of …

From our readers: Mark Smith

April 1, 2015

Dear Editor, Kudos to Rick Thiel, Ed Kavazanjian and Xuan Wu on their excellent article, “Design considerations for slip interfaces on steep-wall liner systems” (February/March, 2015). My consulting practice is principally heap leaching and most of my work now is reviewing designs for complex systems, and troubleshooting when things don’t work out as planned. The …

Comments regarding the Aug./Sept. issue of Geosynthetics

October 1, 2013

To the editor, I just finished reading the excellent Aug./Sept. 2013 edition and felt compelled to share these thoughts with you:  “Market impacts … from coal ash regulation”: This was a very informative update from Boyd Ramsey and Andrew Aho. I’ve read and listened to some of Boyd’s prior commentaries on the Kingston Fossil Plant …

Reader expresses concerns about 4-out-of-5 passing results

August 1, 2013

To the editor: I enjoy reading the GMA Techline in Geosynthetics magazine and the snappy to-the-point answers provided by my friend and colleague, Dr. Koerner. However, I have some concerns with the recommendation to accept 4-out-of-5 passing results for the peel separation parameter for seam peel testing. I do not think a 20% failure rate, …

Our expert answers a question on global warming

Question: Dear Dr. Leshchinsky, In Item 2, “Apparent cohesion,” you state: “In some zones this redundancy becomes more important due to an increase in precipitation intensity caused by global warming.” I was wondering if you could identify the location of these “zones” and the relative or absolute increase in precipitation you are attributing to global …

Michigan P.E. makes a good catch RE: sg

April 1, 2013

To the editor: Great issue (February/March 2013), read it from cover to cover. One thing I noticed though, on page 40 it states: “..were made of polypropylene, which has a specific gravity greater than 1,…” is incorrect. Typically polypropylene has a sg of 0.905 and that is why it floats, not sinks, as alluded to …

Many applications for geosynthetic reinforcement

February 1, 2013

To the editor: The August/September [2012] issue of Geosynthetics highlighted the success of geosynthetic reinforcement in traditional civil engineering applications, specifically walls, slopes, and abutments. The diversity of the markets is a testament to the continued expansion of the industry. Stream embankments, landfills, commercial and residential developments, and bridges were all featured in the articles. …

Missing a part of GRS history

October 1, 2012

To the editor: The article in the August 2012 magazine describing geosynthetic-reinforced soil (GRS) bridge abutments has a major element missing. The author shows an innocence of the history of this technology in that the name of Robert Barrett is absent. I designed and supervised the construction of abutments on a 140-ft tied-arch span in …

Inquiry on geomembrane curtain

August 1, 2012

To the editor: A good part of the June/July issue highlighted the geomembrane curtain used at the Whiskeytown Reservoir. After reading the article, I admire the ingenuity of the curtain and its construction to ensure lower temperature water reaching salmon spawning grounds. However, there were important unanswered questions. How was 260,000 sq. ft. of old …

Additional comment added to GMA Techline answer

Editor’s Note: The following question was addressed in the GMA Techline answers from Bob Koerner (Geosynthetics, June 2012). A further comment has now been added. Question Can you please guide me to suppliers of high-temp, approx. 215 F (100 C) liners? Also, the liner should be able to handle up to 200,000ppm TDS (total dissolved …