Understanding Environmental Implications Of CIPP Rehab Technology

By Ed Kampbell, P.E. | April 2009 Vol. 64 No. 4

Compounding this analysis, the rapid volatilization of styrene in the environment has to be taken into account. Acute toxicity studies, by their nature, hold the concentrations of the “toxins” under scrutiny at a constant level for the reported study period. This is inconsistent with styrene’s high volatilization rate in the real world. Further supporting this self-diminishing impact is the fact that styrene has been confirmed not to be bioaccumulative.

V-Dot report

In VTRC 08 R16, the researchers state that a literature review revealed that spills of uncured resin from CIPP installations can cause large fish kills. This author could only find one written example of such a purported occurrence: a Lockheed Martin Energy Systems internal report dated Aug. 17, 1995, that recounted the installation of 280 feet of 36 inch diameter CIPP into a storm water pipe. The CIPP was cured using hot water and during processing it was estimated that “approximately three to four gallons of uncured resin extruded into the manhole at the lower end of the liner.”

Because the storm water system under rehabilitation discharged into the East Fork Poplar Creek, the project engineer had directed the installer to hold the process water in the cured liner until it reached a temperature of 72 degrees F before discharging it into the downstream piping and subsequent holding lake. Normally, the installer’s processing steps called for cutting a two inch diameter hole to allow the 90 100 degree F water to drain slowly from the cured lined which had been demonstrated to cure “the extruded uncured resin causing it to precipitate out as an insoluble solid.”

The post installation discovery of a fish kill in the East Fork Poplar Creek having a measured dead count of 5,500 fish was quickly attributed to a styrene release when a quantity of uncured resin was found in the downstream manhole of the lining work. The concentration level of the water in the manhole was around 100 parts per million (ppm). Curiously, the styrene concentration in the holding lake downstream at this same point in time was found to be 0.066 ppm (the outfall point to the creek was not sampled). No information was given in the posted report to ascertain the validity of the assumption that styrene was indeed the culprit. Certainly a discharge containing 0.066 ppm or less would not have triggered such an occurrence.