Day 3 from Dubai featured a special workshop on high-density polyethylene (HDPE) geomembranes.
(See the Day 1 story here and the Day 2 report here.)
One resin manufacturer, a geomembrane manufacturer, a design engineering representative, and a liner installer attended and participated in lively discussion during the day-long post-conference workshop on HDPE geomembrane. These workshop participants came from Switzerland, Saudi Arabia, and the United Arab Emirates and the workshop was led by Dr. Ian D. Peggs (I-CORP). Key topics included liner leak statistics, consequences of leakage, action leakage rates, finding the responsible leaks, and estimating the remaining exposed geomembrane lifetime.
Most, except the resin manufacturer, were surprised to hear that different HDPE geomembranes have different mechanical durabilities as assessed by oxidative induction times, carbonyl index, and stress cracking resistances. Thus, the term "HDPE" was likened to "car" in that all cars are not the same–there are commodity vehicles and there are performance vehicles.
All were surprised to hear that all individual geomembrane liners are most safely designed using a specified maximum allowable (action) leakage rate above which the responsible holes must be immediately found and repaired. A "Zero" leakage rate is impractical if for no other reason than water vapor diffusion (US EPA’s "di minimis" leak rate) through a liner without any physical holes will occur to some degree.
All attendees appreciated the use, and appropriateness, of applied potential geoelectric liner integrity surveys for the final stage of liner installation CQC/CQA.
And everyone said that much more education of engineers and regulators in the Gulf region is necessary regarding the use of geosynthetics.
Overall, the two-day Geosynthetics Middle East conference arranged by SKZ and BMC Gulf and the day-long post-conference event was a successful step in that direction.
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Ian Peggs is president of I-CORP International. Visit I-CORP’s website at http://www.geosynthetic.com or write to him at icorp@geosynthetic.com.
