Excess Methane Smell

[MasterPlumbersKeymaster]

I am having an extremely difficult time solving a venting problem. I don’t know if the problem is in how my septic tank is draining or whether I have a leak in my venting system. I had the plumber who installed the entire sywtem come and inspect if there were any traps being syphoned off and he determined that that was not happening. How does one determine if the smell is a drainage probelem or a leak in the venting?
The roof vent does ice over, so I must keep that free of ice. When the shower drains, and the roof vent is ice free, there is a methane smeel that creeps in the house.

[SylvanLMPParticipant]

Increase the vent terminal to 4″ diameter and have it extend 12″ above the roof if this roof is used for weather protection only.

[RichardParticipant]

You cannot possibly be smelling methane. It is an odorless gas. You are probably smelling a thiol or mercaptin. They add ethanethiol to household gas in the parts per billion range. When it comes to thiols, the human nose is more sensitive to it than any detection device on the market.
These classes of compounds (thiols and mercaptans) are released by anaerobic germs. While unpleasant, there is almost no health risk when they are in small concentrations.
You should definately follow Sylvan’s advice on this matter.

The Friendly Chemist

[John Aldrich1Participant]

MNFamilyMan, I suggest that you perform a Peppermint Oil Test to determine if you have a leak in your vent system. If you do not know how to perform this test, send a private e-mail to Sylvan, and he will tell you ALL you could possibly want to know (and then some) about the Peppermint Oil Test. JWA

[SylvanLMPParticipant]

John I am glad to see you know when something is out of your league (field) and you tell folks to see the experts rather giving erroneous information sight unseen

John I guess you have learned a little bit of knowledge is very dangerous.

This is EXACTLY why I no longer have “helpers” on my payroll.

Unfortunately the really talented apprentices like Frank take the brunt of past stumble bums dabbling in these trades

Now back to this posting John AGAIN you gave BAD ADVICE sorry to say guy.

Perhaps you should read some postings rather then jump in making all the wild unfounded suggestions.

Lets THINK like a mechanic would and digest what this gentleman is saying instead of a non professional approach of wasting chemicals and time.

>>>>I am having an extremely difficult time solving a venting problem. I don’t know if the problem is in how my septic tank is draining or whether I have a leak in my venting system < <<<. POW HINT lets keep reading OK Johnny

>>I had the plumber who installed the entire sywtem come and inspect if there were any traps being syphoned off and he determined that that was not happening<<<.

OK so the plumber checked the traps for back pitch hopefully and he did install them LEVEL and checked them for a possible string or rag or other absorbent materials to see if capillary attraction maybe the cause of trap seal being sucked out
GREAT starting point.

Now this brings us up to another QUESTION Johnny THINK before I give you the NEXT clue to this puzzle.

1- Mississippi

2-Mississippi

3- Mississippi

OK John TIME is UP WHAT is missing here?

TA DUM John the MNFamilyman NEVER mentioned about the “plumber” putting on a test of either 5 PSI Or a 10 ft head of water (hydrostatic) to TEST the integrity of this system (Drainage AND venting)

TESTING is VERY important and SO is getting this job inspected and approved.

John NOW for some guidance.

We know that there is a smell SO why do a PEPPERMINT TEST to MASK another smell?

Doesn’t make sense? Does it?? NOW that you have been shown the error of your thinking lets continue EDUCATION and REASONING time

>>How does one determine if the smell is a drainage problem or a leak in the venting?
The roof vent does ice over, < Hey John POW INSIGHT hey Johnny READ this GAIN slowly OK

The roof terminal is blocked THUS NO VENTING possible CLUE here JOHN PLEASE re read it again

OK John at this point we don’t need oil of peppermint Or smoke test.

What the thing to do is?? We need to correct this vent problem FIRST step by step.

John not taking shots in the dark THINK about it.
WE know this is a problem LETS correct this one first process of elimination

>> so I must keep that free of ice. When the shower drains, and the roof vent is ice free, there is a methane smeel that creeps in the house.<<<

OK John shower being used WATER going down Drain NO VENT to alleviate BACK pressure like pouring water or soda out of a JUG this DRAIN is STARVING for air
WHOOSH JOHN smell city as the drain is NOW serving as a WET VENT

JOHN
SEE how much YOUR learning? John by listening instead of wasting oils and smoke bombs and just GUESSING without READING the great information this fellow is HANDING you on a platter

Hey john let me explain something about the science of plumbing the KEY IS “LISTENING” to the victims complaint DON’T guess THINK like US skilled craftsmen.

Lets continue John with this education.

OK lets go over the facts

1- NO test was mentioned Hydrostatic

2- The Vent terminal

A- Gets blocked with Ice internally

What does this tell you Johnny?

It tells us he life’s in a colder climate and this vent pipe should be a minimum of 4″ to prevent Hoarfrost (Vent closure) AND come on John were on a roll DON’T STOP SAY IT JOHN come on DUDE you know? TELL HIM

OK ILL TELL HIM

He has to raise the vent terminal HIGHER also to prevent snow accumulations from reaching over this pipe in future snow storms.
for example in NYC we under the OLD code it was 5 FEET ABOVE the roof BUT today we know better so, Oh never mind why confuse you with more facts like promenade decks acid waste venting etc.

You see Johnny a vent carries vapor and in the colder places this vapor can and does freeze on the inside walls of the piping BUT WE being professionals and READ codes and theory KNOW for a fact the ice from this vapor CANNOT BRIDGE a 4″ diameter pipe.

Now once the vent problem is taken care of We can now address the fact that there maybe a missing house trap and this too would allow sewer gases into this structure AND we do not know at this time if the installing “plumber” had installed a FRESH AIR INLET to guarantee FREE movement of air to the vent terminal on the roof.

We also at this time have no clue if these traps are low seal or crown vented and using oil of peppermint would NOT tell us either.

John DONT USE words unless you know WHEN they are applicable (lesson 3)

Once we KNOW for a fact this system was not only sized right BY not only fixture units BUT by developed length of pipe and fittings and it was tested and inspected and all vent pipes are pitching UP from the fixture they service AND all vent piping on the horizontal is of NON scaling materials and we know this plumber is not only a Licensed Master plumber in the area he is working then we can keep moving along until we get this system operating properly with no ill effects to the folks living in this home.

John I knew it took guts to admit you dont know as much as you wanted folks to think BUT hey it is a start and someday YOU too maybe come a journeyman in a field and possibly licensed.

Please John keep reading and learning as we all learn something NEW everyday.

I know I do as plumbing is an on going education NEVER EVER to be mastered completly

Look at me I only scratched the surface in plumbing/heating/drain cleaning/ welding/ fire suppression systems/ boiler and pressure vessel inspections.

Amazing so much to learn and so little time HAVE a GREAT Holiday John

[GuestParticipant]

Family Man: Septic tank systems can have problems such as you have described. This is especially true
during cooler weather. The gasses evolved from the decomposition of organic materials in the septic tank are much warmer and lighter than the surrounding air, and also contain appreciable amounts of Hydrogen (Methane and noxious poo-poo odors).
These gasses are anxious to leave
the confines of the septic tank by any avenues available.
If the ingress pipe from your homes’ building sewer is not turned downward in the tank with the end clean-out in place, that stinky gas concoction will very easily “burp” its’ way up the sewer and drainage lines to your house.
By installing a running trap on the sewer line at or near the septic tank with a vent on the tank side of the crown weir, the problem in your home will most likely cease to be a problem.
Or you can add “Bean-0” laced with 2 0zs. of “oil of peppermint” to the septic tank occasionally, this won’t solve the problem; but will help disguise the aroma generated by your flatulent septic tank.
Serious thought needs to be given also to the frost closure of the roof vent(s). There are heater tapes thap can be installed for that purpose, or you can enlarge the existing vents(s) one pipe size and increase the height to 12″.
Merry Christmas…Bud

[John Aldrich1Participant]

MNFamilyMan, If the peppermint oil test reveals that you do in fact have a leak in the vent system, and you cannot locate said leak, then have a Licensed Master Plumber perform a proper “Smoke Test” so that you can visually locate the leak, and have it repaired.

I doubt that a malfunctioning septic tank will cause sewer gas odors to enter the house, UNLESS sewage is backing up into a drain. You may also consider removing the septic tank access lid to inspect the level of the sewage in the tank. If the sewage level is at the outlet invert elevation then the septic tank is functioning properly. JWA

[Frank HiebertParticipant]

The previous posts from Sylvan and Bud are bang on…if indeed you do have a venting problem. My only conern is that in your post you talk about a methane odor (this is of course mercaptin), and not a rotten egg smell (hydrogen sulfide), which is the most common smell associated with backed up sewars and the like. From this I will bring another variable into the equation by asking you this. Is your house running on natural gas? Maybe your hot water tank is running on natural gas? When you take a shower you are no doubt using a lot of hot water. And it is at this time that you say you are smelling the methane (mercaptin) the most eh. You see where I’m going with this? If your problem isn’t solved from the previous posts I would definitly have your gas line distribution piping tested right up to your hot water tank. By a professional of course. Good luck

Frank Hiebert
3rd yr apprentice
Edmonton, Alberta

[SylvanLMPParticipant]

quote:

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Originally posted by Frank Hiebert:
The previous posts from Sylvan and Bud are bang on…if indeed you do have a venting problem. My only conern is that in your post you talk about a methane odor (this is of course mercaptin), and not a rotten egg smell (hydrogen sulfide), which is the most common smell associated with backed up sewars and the like. From this I will bring another variable into the equation by asking you this. Is your house running on natural gas? Maybe your hot water tank is running on natural gas? When you take a shower you are no doubt using a lot of hot water. And it is at this time that you say you are smelling the methane (mercaptin) the most eh. You see where I’m going with this? If your problem isn’t solved from the previous posts I would definitly have your gas line distribution piping tested right up to your hot water tank. By a professional of course. Good luck

Frank Hiebert
3rd yr apprentice
Edmonton, Alberta

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Frank RIGHT ON this would explain the “Smell” during a HOT SHOWER
The hot water could be the source of the smell COMPOUNDED with the hot vapor of the waste line freezing on contact with the vent terminal would cause this smell to be very noticeable. Thankfuly this gentleman doesnt have SMOKE MASTER John filling his home up with smoke or oil of peppermint..

Now I am wondering WHAT DOES John know about . Becareful what terms you use as John may end up suggesting folks put a “mercury” test to check pressure.

Frank, again excellent point VERY astute.

Now this is plumbing. Sylvan

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