NGWA Event and Education Recordings Archive

During the last 16 years of groundwater remediation activities at Lawrence Livermore National Laboratory’s Site 300 explosives test site, there have been multiple cases of contaminants being inadvertently introduced to groundwater treatment systems from treatment system components, treatment system construction materials, and treatment media. These included plasticizers diffusing from nylon tubing used for extraction well-field pumps, residual organic compounds from the use of PVC glue and thread adhesives, residual organic contaminants in ion-exchange resin left over from the manufacturing process, and internal contamination of treatment media vessels from internal anti-corrosion coatings. Most cases were discovered during initial startup of a new treatment system, after system shutdown periods, or at cyclically operated treatment systems where the water had longer residence times with the contaminated materials. It is not safe to assume that materials provided by companies catering to environmental cleanup are free of contaminants and ready for immediate use. It was surprising to learn that many of these supply companies list accreditation with NSF/ANSI (NSF International Standard/American National Standard), and in particular Standard 61, Drinking Water System Components. This standard establishes the minimum requirements for the control of potential adverse human health effects from products that contact drinking water. LLNL has worked extensively to minimize the impacts of introduced contamination. Tubing materials were chemically evaluated, and test stands were used to evaluate glues and sealants. The arrangement of treatment media vessels at groundwater treatment systems were modified to reduce releases of potential contaminants. Ion-exchange resin leachate testing methods were developed and special procurement contracts were established to include acceptance criteria for the purchase of all ion-exchange resins. All treatment media vessels are cleaned and then soak tested to evaluate any internal contamination prior to being put into use.