Health Concerns Mount as More Old Sewer Pipes Are Lined with Plastic
scientificamerican.com
scientificamerican.com
Code inspectors often use the “peppermint test” to test all the above. They dump concentrated peppermint oil into the sewer then go around the building and see if you can smell it. If you can then you have problems with the plumbing.
Buildings having issues likely have bad plumbing and thus their occupants were likely breathing sewer gasses for ages... the “liner fumes” just made all this more obvious.
Maybe it shouldn't cause backpressure if done properly, but maybe some construction companies carelessly block one side of the pipe while it's curing?
They never once implied the fumes were entering via the plumbing.
In fact I will quote: "Emissions from a nearby CIPP job got indoors through cracks in the building’s foundation and irritated workers to the point that they evacuated"
EDIT: Nevermind, I originally was thinking that a sufficiently negative pressure differential could overwhelm the capacity of the vent. But the more I think about it, the pressure range that I'd expect even with an unusual operation probably wouldn't be far enough outside normal range to do that. ...although there are definitely still some possibilities to do some stupid.
This would only be temporary, but if gases have accumulated near the trap they could diffuse back through the trap and into the room. These would seem to be exceedingly temporary situations however and not likely a source of chronic exposure to pipe gas. The only exception here might be if some HVAC imbalance keeps the ambient pressure in the room at 3-5" of head pressure over the vent.
On the top floor of a building I worked at long ago, there was a drain in the floor of the men's bathroom. It had a p-trap but on windy days there was enough vacuum from the vent stack to drain it out. I encountered a neighbor pouring a cup of water into it one day and he explained the problem. I started doing the same, and had to do it every couple weeks during windy periods.
But I think that's a problem for the upper floors, both due to fluid dynamics and because the first trap that loses seal would mostly restore equilibrium.
Anyway, everything uses PVC, right?
I don't see any claims in the article that the odors entered the building via the sewer pipes. What makes you think that was the path that the odors followed? It could have just as easily been through an open window, or the pipe work could have been near an HVAC intake for the building.
I don’t think new air would be introduced unless the system contains an HRV or ERV.
Additionally, this sounds like improper venting, which is a surprisingly common occurrence.
So the gases could be coming up from the drains and toilets.
In the steam curing process high temperature water is circulated through the pipe to cause the resin compound to catalyze (industry term is "kick"). Steam is not allowed to escape from the liner into any sewer laterals. In fact, sewer laterals are plugged by the liner and have to be reinstated (cut out) by a robot afterwards. At the end of the process the steam is released to atmosphere, it tends to have an odor. From my understanding the odor is styrene, a common industrial solvent.
Sometimes people with flaws in their plumbing report the odor is coming from the drain. This indicates they could potentially have a more serious issue: chronic exposure to sewer gases. I always recommend they have a plumber investigate. Other times the airborne plume is enough to cause very sensitive individuals to complain. There are many industry veterans who have been working with these materials for decades - if you were serious about studying the potential for harm, you would follow this group. They are the canary in the coal mine. Folks with only transient exposures are at very low likelihood of harm.
The American Society of Civil Engineers gave the sewer systems in this country a grade of D+. Just above failing. In reality, and I see this every day, our sewer systems are in need of immediate overhaul. CIPP is a keystone technology for renewal of these assets, because excavation is too dangerous(!) and expensive to be our primary mode of repair.
FYI - pipeline characterization and renewal is a growth industry with a lot of opportunity for AI. In my opinion, a lot of these processes could be automated.
Video below shows the CIPP process. https://www.youtube.com/watch?v=Swp81X4jSDk
I have never taken those reports seriously (even as a card carrying member) and I suggest nobody else do it either.
Is there resin on the side of the liner that's plugging the lateral? In other words, you may still get odors if the thing that's doing the plugging is releasing chemicals on its exterior.
They’re cured from the inside out but the whole thing is “resin”.
The more important point though is that any odor that is coming in from the line is indicative of a problem with the lateral connection - if odor is bleeding off from the CIPP install then there is every indication that sewer gases are also making their way in. There is no positive air pressure exerted by the install on the lateral due to the curing process.
Edit - just to clarify, the point is that you shouldn’t be smelling ANYTHING if the connection is in proper order - odor from the CIPP install or from sewage. If you smell one but not the other then it most likely is NOT the connection because there is no (substantial) difference in the driving air pressures between normal operation and during CIPP installation (because the CIPP seals across the lateral, preventing pressure in the lateral). If you smell the chemicals during install then it is imperative you get your line checked because you are most likely (~100%) also breathing in noxious fumes from sewage and you are so accustomed to it that you no longer notice it.
Is this a thing that is possible for humans? I shudder to imagine this, so much exposure to sewage that one ceases to notice its odor.
Beyond that, it can happen in an acute sense as well. Hydrogen sulfide becomes undetectable above a certain exposure. You will usually pass out shortly afterwards (and then die because hydrogen sulfide is heavier than air and you are now on the floor). The standard advice given for people who enter confined spaces is that if you smell hydrogen sulfide (rotten eggs) you should be aware and check your sniffer. If you are still in the confined space and you suddenly stop smelling rotten eggs, you are literally seconds away from dying and should retreat to fresh air immediately or deploy SCBA.
Well they are doing this because the underground piping is presumbly cracked and/or porous; this would enable fumes from the process to leech into buildings through the pipe walls. We are only protected from sewer gases if the entire system is air tight.
It is also possible that her building had some issues with its plumbing; for instance I have seen fitures removed either during renovation or even on a permanant basis that were not properly capped off--while there would be some constant leakage of sewer gas it is really not dangerous (or even that noxious) in low concentrations; the chemicals used in the lining process however might be.
They did it on my block when I was telecommuting from my front porch. The smell comes from the excavation holes. It's loud process and they use high pressure air to do it. It smelled like somebody stained a deck, and lasted about a half hour. There was some residual smell that mostly went away after they covered the hole. You wouldn't know it had happened a few hours later.
If you've ever dealt with the public with stuff, people freak out about anything smelly or any visible involving radio.
The building drainage system in many areas is not "protected" by a house trap. Many municipalities require a backwater water valve which is essentially a check valve with a mechanical moving part. I can easily envision (and I have held a Master Plumbers License) this failing.
Furthermore once you trench to bring sewer, and water into a building (these services while in a manner of speaking are kept separate they often share a common or very nearby trench) it's very easy to not backfill properly thereby also allowing vapors to enter a structure in some instances. It depends: did they use dynamite to blast for the foundation or to bring in these services? There are all kinds of variables that could allow trench to building fumes.
I agree people do freak involving odors, but on the other hand different people have different actual physical tolorances to chemicals.
Yes, the trap seal was lost to evaporation (assuming it's properly vented). People I know at times ask me why their basement shower (most often) smells--same thing; no trap seal due to evaportion from lack of use. And Yes, this is another way her building might have taken on fumes... many variables; heck it might have been sucked in from the HVAC system, and not have anything to due with the plumbing.
- while agreed that a trap should help contain gasses, in order to cure the resin involved they have to inject high-pressure steam into the piping... possible that it could cause bubbles to pass through functional traps
- even if the trap system worked perfectly, the fumes from the cure process get vented to the local atmosphere through outlets set up during the CIPP process. This exposes workers to the largest amount of byproduct chemical vapors, but it's entirely reasonable to think that it could get accumulated or trapped in buildings as well.
The CDC has a good article about this very topic: https://blogs.cdc.gov/niosh-science-blog/2017/09/26/cipp/
The article states that airborne particles and gasses can travel quite a distance to affect people that aren't in the localized application area of the CIPP sites.
> Emissions from a nearby CIPP job got indoors through cracks in the building’s foundation and irritated workers to the point that they evacuated
This is fascinating. I've always thought of dirt and concrete as being basically impenetrable to things like this, but apparently they're not!
The fumes exposure is probably just due to the person's proximity to the job site, not from a plumbing connection.
So I’d really downgrade that “probably” - ambient outdoor exposure maybe, but the facts as presented better fits an indoor exposure during the day.
It's even described in the article you mention.
Or a crack in the stack.
This is common knowledge among the fire fighters here. They knew what was up once they found it.
So, how could VOC be entering buildings where they’re doing CIPP retrofit? Now you know.
This has quite a few voc’s that really give your stomach a churn if you are in close proximity.
ADSL — often required new wiring or a DSLAM on premises to deliver acceptable signal
DOCSiS — same, you have to rewire all coax in the building to deploy it.
House heat insulation — often ends up with inefficient house designs perpetuating because of hopes "we can always add insulation later"
Piping — used to work in a trade company in Canada for half a year as an intern. Tried to import and popularise polypropylene piping there. Got hit by ferocious marketing FUD counterattack by a company selling crap PVC piping in a month after I sent booklets to prospective clients. Their main argument was that "PVC piping is a cheaper "intermediary" solution for plastic piping as PVC pipe can still be joined by plain mechanical means, unlike polypropylene" even when doing so negates their entire point of using plastic piping for its physically continuous joints.
I didn’t finish reading the article, but this sounds amazing. Isn’t plastic one of the least reactive materials we know about and an excellent choice for this? It seems like maybe the issue is in the curing process.
That would explain why 'workers' aren't dropping dead and people far away under the cube law are legitimately sick?
Is this another way of saying the placebo effect?