Easy pipe repair method raises safety concerns

Abstract

When a municipality repairs water or sewer pipes, it faces what seems like an easy decision: Dig up roads to replace the pipes entirely, or thread a tube of polymer resin through the damaged pipes, then inflate and cure the tube to create a new plastic pipe inside the old one. The decision to go with the second option is made even easier because the curing process appears relatively innocuous—it uses water, steam, or ultraviolet light. But studies of the process are starting to show that so-called cured-in-place pipe (CIPP) might not be as innocuous as it sounds. Over the past decade, researchers have found styrene and other suspected carcinogens leaching from the pipes and winding up in waterways. A study published earlier this year investigating steam-cured CIPP projects in the field additionally found that the “steam” emitted into the air during installation was actually a complex mixture of organic