Methane gases in a sump pump pit - question

[Chucky_ott]

HRV/ERV's have to be balanced so as not to get a negative pressure inside the house. That's usually done with a flow meter or magnehelic gauge and then adjusting the dampers on the intake and exhaust of the HRV.

Also, anything close to the HRV intake on the outside of the house ?

 

[sk12344]

HRV/ERV was installed with flex duct (yuck), so there are likely any dampers in there and I don't see any inside the box when I open it. Plus, Wednesday when I got the high readings in the sump pit, the ERV/HRV wasn't even running. It was never installed to switch on/off automatically when the hvac system runs. We run it manually with an on/off switch mounted on the wall. Only good thing is it keeps us from having to unplug it in the summer months when the humidity is super high and we don't use it.

Nothing outside where the intake and exhaust outlets are located. Certainly nothing related to methane. The propane tank is on the opposite side of the house, about 30 yards away.

 

[Sponsor]

 

[Jadnashua]

Years of farming may have left enough organics that are now breaking down into methane under/around the house.

If it's isolated to entering only from the sump, I'd try to fabricate an air tight lid and include a vent to the outside for it. Just make sure it's not near a window or door that might let it back into the house.

 

[sk12344]

I'm wondering the same thing. Still in the process of having conversations with the local plumber.

 

[Steve603]

I don't think that formaldehyde was ever an issue. "the discovery that drywall used in homes throughout many states may be emitting sulfur dioxide, is causing a great deal of worry for homeowners concerned about the health of their families and the value of their homes." The sulfur dioxide caused electrical circuity corrosion and health issues.

I'm at a loss. Find an environmental firm, ask them to sample the air with a teflon coated sample bag and run it through a HPMS (High performance mass spectroscopy) Any gases create peaks as it passes through showing what gases exist. The teflon coated pillow is essential as other plastics can absorb gases such that they do not show up.

The gas company can poke some probes around the house, and check it. I wish you luck in finding the issue.

 

[sk12344]

Did a little test today. The sump pit and the sewer ejector pit are within 12-14 inches of one another. So I flushed the toilet in the basement a couple times to force the sewer ejector motor to run for a few seconds, then went back and put the methane detector probe in the sump pit again and got >640 ppm. Highest reading yet. And it's the highest reading available on my sniffer. Checked it again and it was back down to >80 ppm. So, I'm guessing there's a crack or a leak in the sewer crock itself or in the inlet line coming from the bathroom. Plumber has been called, hoping to schedule a time for him to come out here soon.

 

[Reach4]

So, I'm guessing there's a crack or a leak in the sewer crock itself or in the inlet line coming from the bathroom.

You need that 2 inch vent from the sealed sewer crock to the roof, as Terry pointed out in #2. As sewage comes in, air gets pushed out to the roof.

 

[sk12344]

The sewage grinder pit IS vented to the roof. And all of the roof vents are open. I was up on the roof checking them myself yesterday.

 

[sk12344]

Update - waiting on plumber to arrive this afternoon.

Did some testing of sink / tub / kitchen drains in this four bathroom house and got readings at every drain except for the mud room. Weird...!

The ERV / HRV (manual on/off) was not running when I did the testing, nor was the hvac system running. So, there shouldn't have been any negative pressure to draw in any fumes. And what the heck is methane doing in sink / tub drains anyway?

 

[sk12344]

Appt with plumber bumped back to tomorrow. Apparently a lot of people are having plumbing problems with the current cold weather.

 

[sk12344]

Well, the plumber left this morning without running a camera auger thru any of the tiles because he couldn't smell anything. Showing him the readings that I've been getting from sink / tub drains, plus the sump pit, didn't seem to make a difference. If he couldn't smell it, he wasn't going to check for anything.

I'm still wondering if having a bit of methane in a tub / sink drain and sump pit is "normal". I don't know anyone close by that I would feel comfortable asking if I could stop by their house with my combustible gas detector and check their sink / tub drains and sump pit for comparison. If someone here has a methane / propane detector, would you mind checking your drains and posting a reply with any readings that you found ? Thanks in advance.

 

[Master Plumber Mark]

Update - waiting on plumber to arrive this afternoon.

Did some testing of sink / tub / kitchen drains in this four bathroom house and got readings at every drain except for the mud room. Weird...!

The ERV / HRV (manual on/off) was not running when I did the testing, nor was the hvac system running. So, there shouldn't have been any negative pressure to draw in any fumes. And what the heck is methane doing in sink / tub drains anyway?

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I am willing to bet that the plumber thinks you are nuts...
and he did not want to waste his time or your money.

Their will always be some de-comp going on in all the drains...
not very much but it is what they do.... You can take apart kitchen traps and you can smell a stink from the trap......

I think you might be the fellow that posted over on another plumbers forum ,,,
and good advice was given to you at that time last month.... Am I correct??

#1 seal the sump lid and get a radon guy to install a radon system in the house and it
will suck out all contaminants seeping into the house to the outside... It it does radon
it will also take care of methane....
....
#2 Seal the concrete walls and floor in the basement with epoxy paint

 

[Jadnashua]

A month or so ago, the local gas company was around. They'd just repaired a leaking gas line nearby, and asked if they could check my basement. They got a zero reading throughout my basement. Methane is a natural byproduct from animal waste (a lot of a fart is methane) and organic decomposition. If there's an overabundance of organics in the soil, it may be coming up through cracks in the foundation. If they are drilling and extracting natural gas around where you live, some level may be normal. IF you don't get any outside, I'd consider putting in a fresh air ventilation system so you don't have a negative pressure in the house, and venting the sump outside. It's critical to ensure none of your gas lines are leaking, but it would be unusual for naturally occurring methane in a house to become a problem. If it is there, it can lead to low-level headaches and other annoyances. While at it, I'd also check for radon, which would give you more impetus to go with a mitigation system.

 

[sk12344]

Yes, I'm the same "woman" who posted over in the other forum. I came here so as not to continue "pissing off the pro's" on the other forum.

I am also still in touch via email with one of the guys from that forum who has been very helpful and who also finds the situation quite confusing since listening to the rest of the details. He, too, thinks the sewage extractor is likely leaking and I'm working on getting someone in here to do a visual inspection on it.

Understood that there is always natural decomp going on in drains. But "natural decomp" does not cause headaches, dizziness, nausea, blurred/ double vision, rapid heart rate, burning skin, itching / swollen eyes, etc etc.... in all of the people living in the house.

As I addressed over on the other forum... there is already a radon system in place in this house. The house is 10 years old with a poured foundation and finished basement. There is no way I'm going to waste time tearing drywall and tile floors in order to seal the concrete when I've already pinpointed the area with the potential issue as the sump pit and sewage extractor. Certainly more time efficient to have the extractor inspected.

I am willing to bet that the plumber thinks you are nuts...
and he did not want to waste his time or your money.

Their will always be some de-comp going on in all the drains...
not very much but it is what they do.... You can take apart kitchen traps and you can smell a stink from the trap......

I think you might be the fellow that posted over on another plumbers forum ,,,
and good advice was given to you at that time last month.... Am I correct??

#1 seal the sump lid and get a radon guy to install a radon system in the house and it
will suck out all contaminants seeping into the house to the outside... It it does radon
it will also take care of methane....
....
#2 Seal the concrete walls and floor in the basement with epoxy paint

 

[sk12344]

A month or so ago, the local gas company was around. They'd just repaired a leaking gas line nearby, and asked if they could check my basement. They got a zero reading throughout my basement. Methane is a natural byproduct from animal waste (a lot of a fart is methane) and organic decomposition. If there's an overabundance of organics in the soil, it may be coming up through cracks in the foundation. If they are drilling and extracting natural gas around where you live, some level may be normal. IF you don't get any outside, I'd consider putting in a fresh air ventilation system so you don't have a negative pressure in the house, and venting the sump outside. It's critical to ensure none of your gas lines are leaking, but it would be unusual for naturally occurring methane in a house to become a problem. If it is there, it can lead to low-level headaches and other annoyances. While at it, I'd also check for radon, which would give you more impetus to go with a mitigation system.

As I responded to the person above you.... natural decomp and farts do not cause consistent headaches, dizziness, nausea, blurred / double vision, rapid heart rates, etc etc in several people who live in the same house.

And I think I addressed the other items you bring up... no natural gas drilling / extracting in my area, already having a fresh air ventilation system installed, already did a radon check and have a radon extraction system, also had the propane company come out and pressure check the lines and inspect the furnace... interesting, the propane guy's sniffer spiked high in the sump pit as well, and he agreed "there's likely a sewer leak there because it's not propane, the furnace and the lines are fine" (to quote him).

That pretty much leaves the sewer lines, roof vents, and extractor pit as the suspect items.

 

[Master Plumber Mark]

Just wondering it their already is a radon system in the house then
isnt the sump pump pit already sealed off????


I suppose you could throw some smoke bombs into the stack and sewage system and see what happens...

 

[sk12344]

Yes, the house has a radon system, plus a radon test just last year showed levels on the very low end of the acceptable range. And even if it was high, radon (to my knowledge) also does not cause headaches, dizziness, nausea, blurred / double vision, rapid heart rates, etc. Also, re: the sump pit, no, the lid is not sealed. If it was sealed, I would not be able to stick the probe of the gas detector into the U-shaped hole in the lid, nor hold the probe above the hole, to take measurements.

Still trying to get someone out here to inspect the extractor pit. The local guy we're working with now is not known for his punctuality.

Back in 2016, the check valve on the extractor pit failed and it took a while before anyone noticed. I'm wondering if the water rushing down the extraction tube and back into the basin may have somehow damaged a seal.... or if there's been a fume leak going on for sometime... that is leaking below the concrete in getting into the inlet to the sump pit which is only 12-14 inches away. That's the only thing I can think of as a cause for what's going on.

 

[Jadnashua]

Is there any way to put a pipe into that pit and connect it to the extractor you have for your radon system? You'd still want to seal the pit, otherwise, you'd be sucking conditioned air out, and replacement air in through cracks.

Just an atmospheric vent to the outside with the pit cover sealed should work even without a pump. Just don't terminate it underneath a window.

 

[Master Plumber Mark]

You do not have a proper working radon system, because the sump pump lid is supposed to be TIGHTLY SEALED......


If you can put a meter down in the sump pump pit ...
then the RADON system was never installed correctly.... and the METHANE gas that you are metering down in the pit can come out into the basement
.. ITS WIDE OPEN..... can you understand this????

I would try to use come common sense here and get the sump lid properly sealed and maybe get someone in there to look over what some doof sold you claiming to be a radon system.

Here....... look at radon lid on a sump pump pit
,https://s3-media2.fl.yelpcdn.com/bphoto/DtPbTsrNiELJY93d_SiDxQ/o.jpg

 

[sk12344]

Update ~ Sewer fume leak from the sump pit inlet CONFIRMED via smoke test by a plumber this morning.

For now, we've capped the inlet to see if that helps. Will watch for a few days. If everyone starts feeling better and the gas detector shows no alarms, then we'll know we've isolated the problem area.

Then we have to figure out: did someone connect a sewer line to the sump pit line or, is the sewage extractor pit leaking fumes under the concrete floor where they are intermittently finding their way into the sump inlet. And why is there a draft of air coming thru the sump inlet....? Still haven't figured that one out yet.

Plumber also validated that my combustible gas detector is not only a good one, it's the same make / model that he uses.

I did use "common sense". I found a plumber who finally took me seriously, did a smoke test, and confirmed the problem.

Thanks for your "help".... can you understand this ? Radon does not trigger an alarm on a combustible gas detector. Nor does it trigger headaches, dizziness, nausea, blurred vision, and fatigue. Sewer fumes do that.

Signing off.