Understanding Environmental Implications Of CIPP Rehab Technology

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

At site number four, the storm water pipe only carried flow during rainfall events so the researchers chose to pour one gallon of distilled water into the inlet of the pipe and capture it on the outlet end; that’s one gallon of water running through 121 linear feet of 24 inch diameter pipe. While the researchers stated that upstream samples were taken at sites 2, 5 and 7 at the commencement of testing, upstream samples were not taken at sites 1, 3, 4 and 6 at the commencement of their monitoring.

Additionally, no upstream samples were taken throughout the course of the study which could have provided the user of the report with confidence that the styrene concentrations post installation were the result of the newly installed CIPP. This fact was particularly disturbing to the NASSCO styrene task group as the flows carried by these storm water installations carry flow from the roadway. Automobile emissions are a known source of styrene in the environment. A condensed presentation of the styrene concentrations found by the researchers is shown in the accompanying table.

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What is the assimilative capacity of the seven project sites investigated? No analyses were made by the researchers.

Were there any observed fish kills or other environmental impact to these project sites? None were reported by the researchers.

As these are storm water pipes, the contaminate loading rates should have been assessed based upon the assimilative capacity of the receiving waterway and the aquatic species therein. Instead, the concentrations measured by singly taken grab samples were compared against the maximum contaminant level for styrene in treated drinking water: 0.1 ppm. Additionally, we were provided with reference levels of styrene concentration for the water flea (48 hour E50) and rainbow trout (96 hour LC50). From the lack of documented environmental impacts at these sites, one can logically conclude that the assimilative capacities of the receiving waterways were, in fact, not exceeded by the direct discharge of the measured styrene concentrations from these CIPP processing operations, or by the subsequent styrene concentrations measured in the storm water flushing of the newly installed CIPP.

Preliminary findings