An Investigation of Water Quality and Aquatic Toxicity Concerns of CIPP Rehabilitated Infrastructure

Sanitary sewer collection and stormwater conveyance infrastructure is increasingly being repaired by trenchless pipeline rehabilitation methods such as cured-in-place-pipe (CIPP). This project was conducted to determine the degree the CIPP installation process and cured material impacted stormwater quality. Condensate generated during the installation was characterized. Stormwater was monitored for five weeks. Cured CIPP was also extracted in a lab oratory. Waters were analyzed for chemical oxygen demand (COD), UV absorbance, presence of volatile and nonvolatile contaminants, a s well as their toxicity to Daphnia magna. Results demonstrated that CIPP installation activities contaminated stormwater at and downstream of the installation sites. For five weeks following CIPP installations stormwater was found to be contaminated as demonstrated by elevated COD levels and the presence of styrene. Styrene is one of many compounds that were released into the stormwater by the CIPP process. The CIPP process liquid contained a pH of 6.2,36,000 mg/L COD, and elevated styrene level. This liquid totally dissolved D. magna organisms during the toxicity test within 24 hr; no organisms remained for mortality counting. When process liquid was diluted 10,000 times, 100% mortality of the D. magna occurred.