Cured in place pipe is becoming more common for both commercial and residential purposes. The government has long been using CIPP repair to avoid large-scale delays. It’s much easier to reline a culvert than replace it. During this time, the opinions of CIPP’s effects on the environment have been contested, but generally come up clean.
CIPP is not a new technology. While the process is always being refined and perfected, it has existed in essentially the same form for forty years. The process is simple. A woven pipe liner is soaked in resin, this resin is then hardened inside the pipe that needs to be repaired or replaced. This forms a new, plastic pipe inside the former pipe. After this pipe is hard, service can be restored. This provides a quicker process than traditional pipe repair. The process for traditional pipe repair includes digging a trench, replacing the pipe, and then repairing the land above it. This could add days or weeks to the project if you have to replace your driveway, a public highway, or your garden.
The most contested environmental factors focus on styrene. Styrene is one of the chemicals used in CIPP resin. CIPP repairs only release styrene while the pipe is soft. Once it’s been cured, there’s no evidence that styrene continues to leak. Concerns about styrene revolve around its possible place as a carcinogen. This has not yet been proven. There was a move by the USA to classify it as a possible known carcinogen. This means that there is a risk, but that risk has not been comprehensively tested. The CIPP industry and others who work with styrene are calling for a full investigation. Until then, styrene is in limbo—but the testing continues to remain in favor of CIPP.
A 2012 report on public use of CIPP repair over fifteen states showed that only four of them had any problems with CIPP lining in the prescribed time. This means that eleven states reported perfectly clean results from installation. Of the four states where tests were necessary, one showed styrene leakage of a very low quantity. Rainbow trout are considered a signal special; environmental factors hit them hard. In this case, the rainbow trout were perfectly fine living in levels of styrene that are acknowledged to be higher than projected. Of the other three, only one resulted in a fine to the installer.
Though we’re still waiting on the comprehensive study on styrene and its affects, we don’t have to wait to isolate the cause of leakage. In each instance described by the 2012 study, improper installation was cited. This primarily means that water flow was not totally diverted around the uncured pipe. Water flow over the soft resin resulted in leakage. In cases where the pipe is fully cured before use of the line is restored, these issues weren’t reported. Getting a trusted installer is key to CIPP repair success.
CIPP is a less invasive and destructive option for pipe repair. Environmental factors need to be thoroughly addressed, but at the moment there’s no evidence that properly installed CIPP leaks styrene. Additionally, we’re not even certain that styrene is harmful. Until the definitive study happens, you can move forward, confident that properly installed CIPP doesn’t pose an environmental risk.