Understanding Environmental Implications Of CIPP Rehab Technology

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

The question going forward is, have installers been missing any required permitting? In the short term, the requirements have resulted in some of the installers not bidding the DOT’s projects while they sort out these new requirements. Others continuing to bid the work claim pricing has approximately doubled since implementation on the new rules. The environmental costs to transport the water used in the CIPP processing (increased engine emissions, diesel usage, etc.) have not been quantified. It is logical to conclude, however, that there has been a negative environmental and economic cost to the new requirements. Is this added cost technically justified?

In the newly issued NASSCO Guideline for the Use and Handling of Styrenated Resins in Cured In Place Pipe, it was concluded that “All that CIPP resin systems require is that good housekeeping be practiced by the installation team on the project site.” Further, provisions must be made by the contractor in advance for containing any accidental spillage of the resin on the work area. By law, spills less than the hazardous materials “regulated quantity” of 1,000 pounds of styrene (2,500 pounds of resin) are to be handled in a responsible manner by the contractor. Absorption with an inert material and placing in an appropriate waste disposal container is the industry standard for handling small spills like this on the ground. Oil dry, kitty litter and sand work well for this action. If the spill occurs on a hard surface, the area should be scrubbed with soap and water after the bulk of the spill has been cleaned up by the absorbent material. If the spill gets into a waterway, the spill should be contained using a temporary dike. The resin can then be picked up by vacuuming the resin into a vacuum truck and subsequently placed in an appropriate waste disposal container.

It is imperative that the processing of the liner, whichever method of curing is used, is properly completed. Properly cured liners release little or no styrene to the environment. Thermocouples placed strategically in the liner host pipe interface are a must. A written curing schedule developed for a CIPP system acknowledging the conditions that can be present in the curing environment and the resin system proposed will lead to a proper cure and a long CIPP life; and, in this author’s opinion, no measurable environmental impact.

In the NASSCO guideline, proper curing and handling of CIPP systems is recommended to be implemented using the following steps:

Water Curing

Sanitary Sewers