Sounds like the building has other more serious plumbing issues. Gasses and odors of any type shouldn’t be able to work their way back into a building via the sewer pipes. The pipes in the building can’t leak and that’s one of the reasons why properly installed drains have traps.
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.
> Gasses and odors of any type shouldn’t be able to work their way back into a building via the sewer pipes.
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'd suspect it's more likely the opposite: as the pipe is dewatered it creates a negative pressure that pulls the water out of the p-traps which then temporarily allows gaseous exchange with the building air.
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.
The liners are apparently being hardened with steam or hot water. That still shouldn't cause backflow, "rising air" isn't worse than diffusion and the little bit of extra pressure from heat should head down-pipe before pushing through traps. But it does sound like a suspect for why this is showing up now in plumbing that hasn't had issues with other smells.
Well if someone wasn’t following procedures then I suppose anything is possible. But the general premise of the article (that ‘fumes’ are making their way back into perfectly good buildings via the plumbing) is problematic.
I'm a professional engineer with experience on these types of projects. CIPP has been used since the 80s, in the US as well as Europe (and I presume Asia and Oceania). Originally it was done with hot water, though steam curing processes have an economic advantage today. UV curing processes are now wide spread as well.
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.
I don’t disagree with any of the substance of what you said (as someone who has also had tangential experience in sewer rehab work), but it’s worth pointing out that ASCE has a vested interest in constantly throwing out the “nearly failing” grades.
I have never taken those reports seriously (even as a card carrying member) and I suggest nobody else do it either.
> 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.
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.
The whole liner is resin. It is produced in a factory per job (“wetted out”) and then brought to a job on a refrigerated truck then pulled into place and cured via steam/water/UV.
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.
> I see no mention of p-traps [1]. How exactly are these fumes getting into places when there's essentially an airlock in every drain connection?
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.
This isn't in the building, it's way that municipal utilities retrofit pipes in the street that are leaking. If they catch the leak before it collapses, they are able to inject this sleeve and basically put a plastic cast inside the pipe.
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.
There is a water fountain in a neglected corner of my building at work that blows sewer gasses in your face if it hasn't been used in awhile. It's the most horrific stench to inhale right when you are about to drink some water.
> There is a water fountain in a corner of my building at work that blows sewer gasses in your face if it hasn't been used in awhile. It's the most horrific stench to inhale right when you are about to drink some water.
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.
I caught a whiff of this venting to the local atmosphere in downtown SF a few years ago, and it was shocking. The smell is so strong and noxious you can’t believe that there isn’t some serious problem happening in your midst. No warning either. It’s about as frightened of a smell as I’ve ever been.
I haven't read 100% of the article, but from skimming over it, I see no mention of p-traps [1]. How exactly are these fumes getting into places when there's essentially an airlock in every drain connection?
From the article, it doesn't sound like it's coming out of the drains. It sounds like chemicals are being released when they fill pipe sections with steam which then dissipates into the surrounding air.
The fumes exposure is probably just due to the person's proximity to the job site, not from a plumbing connection.
I'm familiar with vents, but indoor vents are basically one-way air valves. I don't know if this is required by code, but it's definitely common practice (you don't want poop smell coming out of your vents)
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.
A p trap can dry out. In my case the resulting sewer gas introduced 120ppm of CO into that bathroom, which started to dissipate and set off CO alarms on the next floor up.
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.
It should be noted the fumes are from the cast in place pipe liner (cipp) which is a Fiberglas style sock that is pulled through the existing pipe and then filled with compressed steam.
This has quite a few voc’s that really give your stomach a churn if you are in close proximity.
I found irrational preference for "retrofit" and "intermediate" solutions over proper replacement even costs are unfavourable rather puzzling.
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.
Readit News
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.
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.
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?
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.
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.
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/
[1]: https://en.wikipedia.org/wiki/Trap_(plumbing)
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.
https://en.m.wikipedia.org/wiki/Drain-waste-vent_system
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!
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.