RAPID: Chemical Air Emissions from Cured-in-Place-Pipe (CIPP) Pipe Repair Activity

Purdue University, West Lafayette IN

Investigators

Abstract

1624183 Whelton Cities and utilities across North America are repairing millions of miles of crumbling sewer pipes using the cured-in-place-pipe "trenchless" renewal technique. At the same time, state transportation agencies across the nation are also relying on CIPP for repairing millions of miles of stormwater culverts. The cured-in-place-pipe repair method involves the installation of a resin impregnated fabric into the deteriorating pipeline or culvert followed by curing in situ with heat (hot water or steam) or ultraviolet light. Cured-in-place-pipe is created by the crosslinking of a polymer resin. Evidence indicates that chemical emissions from steam and hot water cured cured-in-place-pipe sewer pipe repair activities can pose a risk to human health and the environment. The project goal is to understand chemical air emissions from steam cured cured-in-place-pipe installations, one of the most popular cured-in-place-pipe technologies. A December 2015 chemical emission study of three steam cured cured-in-place-pipe installation sites in a U.S. city indicated styrene was emitted into the air at greater than 1,000 ppm, exceeding all regulatory workplace exposure standards. Levels reported far exceeded the International Toxicity Estimates for Risk value of 20 ppm for the most susceptible population such as children. Styrene is one ingredient of steam cured cured-in-place-pipe, nearly 50% w/w in the uncured resin, and a volatile organic compound (VOC). Styrene, a carcinogen (NTP 2015), has an odor detection limit of 0.16 ppm. Steam cured cured-in-place-pipe is one of the most common sewer pipe and culvert repair methods in use today due to its low cost. The proposed work is urgently needed and will provide a better understanding of cured-in-place-pipe site chemical air emissions. Without this project: (1) risks posed to the environment and persons near cured-in-place-pipe installation sites will continue to be poorly defined, and, (2) cities, utilities, and state transportation agencies cannot implement engineering controls that best protect the environment or human health. This project is in response to the scientific needs of municipalities, utilities, and transportation agencies across the nation who are rehabilitating deteriorated water infrastructure, specifically pipelines and culverts. Cured-in-place-pipe is increasingly being installed throughout the U.S. for stormwater culvert and sewer pipe repair applications. New evidence suggests that cured-in-place-pipe installation activity can emit the hazardous air pollutant styrene, among other volatile organic compounds into the air exceeding workplace exposure standards and it is most common that cured-in-place-pipe emissions are poorly controlled. Currently, there is no reliable data set of time-resolved and volatile organic chemical species emissions from cured-in-place-pipe sites. In light of the growing number of emergency response incidents and population health impacts prompted by cured-in-place-pipe chemical emissions, there is an urgent need for the proposed study. Utilities, cities, and state transportation agencies do not have the information needed to develop construction specifications and engineering control strategies that limit chemical air emissions from cured-in-place-pipe sites. Results will fill a knowledge-gap that inhibits infrastructure owners and managers from better protecting the environment and nearby population from chemical air emissions. This project provides an exceptional STEM learning opportunity for Purdue University students.