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Comparison of Fiberglass and Other Polymeric Well Casings, Part I: Susceptibility to Degradation by Chemicals |
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| Authors: | Thomas A Ranney Louise V Parker |
| Institution: | Thomas A. Ranney is a staff scientist with Science and Technology Corp. (PO. Box 127, Hanover, NH 03755). He received a B.S. in education from Castleton State College and an M.S. in plant and soil science from the University of Vermont. His current interests are in the development of analytical methods and in evaluating environmental sampling procedures.;Louise Parker is a research physical scientist at the U.S. Army Cold Regions Research and Engineering Laboratory (72 Lyme Rd., Hanover, NH 03755-1290). She received a B.A. in microbiology from the University o f New Hampshire and an M.S. in food science and nutrition at the University o f Massa-chusetts. Her research interests are in ground water sampling and material interactions. She is a member o f the Association of Ground Water Scientists and Engineers and has been active in ASTM subcommittee 018.21 on ground water and vadose zone investigations. |
| Abstract: | Previous research has shown that the most commonly used well casing materials-stainless steel. polyvinyl chloride (PVC). and polytetra-fluoroethylene (PTFE)-are not suited for all monitoring environments and applications. This study is part of a series of experiments that were conducted to determine the suitability of four other polymeric well casing materials-acrylonitrile butadiene styrene (ABS), fluorinalcd ethylene propylene (FHP), fiberglass-reinlorced epoxy (FRE), and fiberglass-reinforced plastic (FRP)- for use in ground water monitoring wells. In these studies, these four materials were compared with two other commonly used polymeric well casings, PVC and PTFE. Part I of these studies examines the resistance of these materials to degradation by chemicals. Future reports will consider sorption and leaching of organic and metal contaminants. In this study, the six materials were exposed to 28 neat organic compounds (including one acid) and to extremely acidic and alkaline aqueous solutions for up to 112 days. This was done to simulate the most aggressive environments to which monitoring well casings may be exposed. The casings were observed for changes in weight and signs of physical degradation (swelling, softening, deterioration, or dissolution). The two fluorinated polymers (FEP and PTFE) were not degraded by any of the lest chemicals. Among the nonfluorinated products tested. FRE was the most inert. Three organic chemicals caused the glass fibers to separate. and two organic solvents caused weight gains exceeding 10 percent. ABS was the most readily degraded material tested. By the end of the study, only the acid and alkaline solutions had little effect on ABS. FRP was more severely degraded by the organic chemicals than FRH but was less affected than PVC. FRP and FRE. lost weight when exposed to the highly acidic conditions. |
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