Wow this is difficult reading! In the UK most of this work is done by cameras but I guess this is only in newer systems. Actually the largest Sewer pipe I could find in the UK is 315mm? Like this , but how insane would you have to be to send someone into a sewer pipe only slightly larger? Let alone do it yourself under orders.

Genuinely shocking!

Sewer Line Repairs Claim Life

It is fairly common in poor developing countries with low technical excellence in sanitation, to find a sanitary worker killed while working in a sewer line. When this happens in a country like U.S., it is unbelievable. A worker was sent down in a 20- or 24-inch diameter sewer pipe (this is narrow size; how can a sanitation worker be asked to work in such a tight space?) for repair work. The pipe collapsed and the unfortunate person died.

According to Water Online newsletter of 21 Nov 2017 (www.wateronline.com/doc/worker-killed-du...g+Sewer+Line+Repairs ), “The 22-year-old from Gurnee, was doing that job Wednesday when authorities say the resin lining he and his crew installed in a sewer main under a Streamwood residential collapsed, trapping him in the pipe where he ultimately died.” The practice of cured-in-place pipe (CIPP) repair is already controversial for the potential hazards it brings through the production of vapor plumes that accompanies it. In this case, it appears that as Morrow was installing new lining, the pipe gave way with him still inside.

According to Wikipedia, a cured-in-place pipe (CIPP) is one of several trenchless rehabilitation methods used to repair existing pipelines. CIPP is a jointless, seamless, pipe-within-a-pipe with the capability to rehabilitate pipes ranging in diameter from 0.1 to 2.8 meters (4–110 inches). As one of the most widely used rehabilitation methods CIPP has application in water, sewer, gas, and chemical pipelines (en.wikipedia.org/wiki/Cured-in-place_pipe).

Dr. Andrew Whelton, an assistant engineering professor and researcher with Purdue University, believes they indicate a serious health risk to those who may breathe them in.

A paper titled: Worksite Chemical Air Emissions and Worker Exposure during Sanitary Sewer and Stormwater Pipe Rehabilitation Using Cured-in-Place-Pipe (CIPP), authored among others by Andrew J. Whelton, says (abstract):

Chemical emissions were characterized for steam-cured cured-in-place-pipe (CIPP) installations in Indiana (sanitary sewer) and California (stormwater). One pipe in California involved a low-volatile organic compound (VOC) non-styrene resin, while all other CIPP sites used styrene resins. In Indiana, the uncured resin contained styrene, benzaldehyde, butylated hydroxytoluene (BHT), and unidentified compounds. Materials emitted from the CIPP worksites were condensed and characterized. An emitted chemical plume in Indiana was a complex multiphase mixture of organic vapor, water vapor, particulate (condensable vapor and partially cured resin), and liquid droplets (water and organics). The condensed material contained styrene, acetone, and unidentified compounds. In California, both styrene and low-VOC resin condensates contained styrene, benzaldehyde, benzoic acid, BHT, dibutyl phthalate, and 1-tetradecanol. Phenol was detected only in the styrene resin condensate. Acetophenone, 4-tert- utylcyclohexanol, 4-tert-butylcyclohexanone, and tripropylene glycol diacrylate were detected only in the low-VOC condensate. Styrene in the low-VOC condensate was likely due to contamination of contractor equipment. Some, but not all, condensate compounds were detected in uncured resins. Two of four California styrene resin condensates were cytotoxic to mouse alveolar type II epithelial cells and macrophages. Real-time photoionization detector monitoring showed emissions varied significantly and were a function of location, wind direction, and worksite activity.

The process, CIPP, as such, does not appear to be safe, when it comes to a sanitary worker working 20 to 30 feet below ground in a 20-inch dia pipe, even with safety aids. As one comment says: That's what robotic cutters are for?

F H Mughal