?Specific tasks were to (1) survey water utilities to learn about their experiences with plastic pipes and permeation of mains and services, (2) study permeation through PE and PVC pipes exposed to hydrocarbon contamination, (3) develop laboratory tests to predict permeation of pipes and gaskets, and (4) study permeation through pipe gaskets exposed to hydrocarbons. The research team surveyed utilities by mail and telephone to obtain information about their use of plastic pipes and experiences with permeation incidents and successful uses in known hydrocarbon-contaminated areas. Case histories with relevant laboratory data were developed. Permeation of PE and PVC pipes exposed to soil and water contamination was studied in pipe-bottle apparatuses. Novel pipe-drum apparatuses were used to study permeation of gasketed pipe-joints. New laboratory tests were developed to measure and predict permeation through PVC pipe. The moving front test was used in studies that revised and extended the understanding of the theory of permeation in PVC pipes, the thresholds of environmental contamination that might impact engineering decisions, and the impact of combinations of BTEX compounds on PVC pipe. ?

?Specific tasks were to (1) survey water utilities to learn about their experiences with plastic pipes and permeation of mains and services, (2) study permeation through PE and PVC pipes exposed to hydrocarbon contamination, (3) develop laboratory tests to predict permeation of pipes and gaskets, and (4) study permeation through pipe gaskets exposed to hydrocarbons. The research team surveyed utilities by mail and telephone to obtain information about their use of plastic pipes and experiences with permeation incidents and successful uses in known hydrocarbon-contaminated areas. Case histories with relevant laboratory data were developed. Permeation of PE and PVC pipes exposed to soil and water contamination was studied in pipe-bottle apparatuses. Novel pipe-drum apparatuses were used to study permeation of gasketed pipe-joints. New laboratory tests were developed to measure and predict permeation through PVC pipe. The moving front test was used in studies that revised and extended the understanding of the theory of permeation in PVC pipes, the thresholds of environmental contamination that might impact engineering decisions, and the impact of combinations of BTEX compounds on PVC pipe. ?

?Specific tasks were to (1) survey water utilities to learn about their experiences with plastic pipes and permeation of mains and services, (2) study permeation through PE and PVC pipes exposed to hydrocarbon contamination, (3) develop laboratory tests to predict permeation of pipes and gaskets, and (4) study permeation through pipe gaskets exposed to hydrocarbons. The research team surveyed utilities by mail and telephone to obtain information about their use of plastic pipes and experiences with permeation incidents and successful uses in known hydrocarbon-contaminated areas. Case histories with relevant laboratory data were developed. Permeation of PE and PVC pipes exposed to soil and water contamination was studied in pipe-bottle apparatuses. Novel pipe-drum apparatuses were used to study permeation of gasketed pipe-joints. New laboratory tests were developed to measure and predict permeation through PVC pipe. The moving front test was used in studies that revised and extended the understanding of the theory of permeation in PVC pipes, the thresholds of environmental contamination that might impact engineering decisions, and the impact of combinations of BTEX compounds on PVC pipe. ?