Understanding Environmental Implications Of CIPP Rehab Technology

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

In May 2008, the Virginia Department of Transportation issued the results of a study (VTRC 08 R16) of which the purpose and scope was “to evaluate the potential for impacts on water quality from use of the steam cured CIPP process.” Given the potential value of having an independent investigative look at the potential environmental impacts of using styrenated resin systems in storm water system rehabilitation, the industry looked forward to the gains from such a study; and the potential for having the information available to the consulting engineering community as they continued to increase their usage of CIPP in storm sewer and culvert applications. This article will explore the path of the research, findings of the researchers and their technical conclusions.

All engineering projects must contain an environmental assessment of the disruption that potentially might occur as a result of the contemplated work; trenchless pipeline rehabilitation using CIPP is no exception. CIPP projects, because of their short duration and limited area of impact, typically fall under the Environmental Protection Agency’s construction general permit (CGP), if at all. Projects fitting under the CGA requirements are those having an impact area of between one and five acres. This permitting program was established by the EPA in an effort to forego the massive amount of paperwork that would be required to address each individual small construction project such as CIPP work. In my experience, the impact areas of essentially all CIPP projects are less than one acre in size. Further, most DEQ engineers would probably feel that given there is little or no excavation and/or soil movement, this rehabilitation work falls outside of the CGP.

Given such an extremely small project footprint, CIPP project sites should be governed under the broader self oversight requirements for a potentially hazardous material. Self oversight, however, can be a challenge as the EPA has no stated or pre determined limits for discharges of water containing styrene from construction sites. Therefore, the CIPP installer must consider the assimilative capacity of the downstream receiving ditch or waterway to accept the estimated VOC and/or thermal loading that will result from the process methodology as it pertains to the known downstream aquatic organisms.