Sites of seven incidents of plastic pipe permeation were visited between July 1986 and December 1987, and samples of soil, pipe material, and pipe water were collected. In addition, a comprehensive literature review was undertaken to document other cases of permeation. This work demonstrated that the majority of permeation incidents were associated with gross soil contamination in the area surrounding the pipe. Soil contamination occurred mainly after pipe installation, suggesting that soil analysis prior to pipe installation will not significantly decrease the number of incidents. The occurrence of about half the incidents in low risk areas indicates that limiting plastic pipe use to these areas will not be effective in preventing permeation.