Septic Smell unless...

[Brichards]

Hi Team,
It's been a while since I have posted, but I am still experiencing the same issue that brought me to the Plumbing Forums. Hoping that maybe someone has some new ideas or insight.

Here's what's going on...

I live in the country and have both well & septic.
I have two odor problems.

The first is your typical egg smelling well water. It is intermittent, and seems to be there whether it is cold water or hot. Leading me to believe it is bacteria in the well water itself. I have read online that chlorinating the well should resolve this? But I am unsure how to go about doing this, so an instructions or direction would help a ton!

Now the second, more pressing issue, the reason I posted this in the septic forum.
Ever since I moved into my house (12 year old house) I started noticing that when the basement windows are completely closed, I get a septic smell that starts in the basement and then makes it's way throughout the whole house. If I have one of the basement windows cracked, about 3-4inches, the smell completely disappears.

What I have done:
Had the septic tank emptied
Had a smoke test throughout the system checking for cracks/leaks and that the roof vents are working. Came back no leaks and the vents work just fine.
Sniff tested all drains, there appears to be no definable source...

The only thing I can think of is that if the window is closed, it creates some type of vacuum, bringing the septic smell in from the tank somehow? Seems that 3-4inches of a window cracked isn't very much to eliminate the odor as quickly and assuredly as it does.

Any other questions to help diagnose, or ideas to try, would be very much appreciated!
Thank you!
Blake

 

[phishfood]

Just a thought, do you have gas, natural or propane, with any piping in the basement?

 

[Brichards]

Yes, I do have propane with pipes in the basement, but had that checked too. May be worth another soapy spray bottle test myself?

 

[phishfood]

Yes, I have seen leaking propane be diagnosed as sewer gas smell. Use plenty of soap in the water mix. Spray all of the pipe, not just the joints.

 

[Brichards]

Checked my propane gas lines, no leaks. Although I am thankful in a way, in another I am not because the problem persists.
Stranger still, I have been trying to see how much I can close the window in the basement before getting the smell. I now have it open a mere 1.5inches with no smell. If I close it that last little bit, the smell is all over the basement in a matter of an hour or two, then by the following day, it creeps up to the main floor...
Just not making much sense...

Anyone know a good place to find instructions on how to...
Determine the size of my well??
Shock chlorinate it (cold water is definitely smellier than hot)?

Thanks!!$

 

[Brichards]

I have found the problem, but now I don't know what to do with it...

So get this, after trying for years to solve this septic smell in my basement problem, I finally just started replacing drainage pipes in the area of the smell.
Redid the wax seal on a toilet, the flange, and the drain pipe all the way to the septic tank. Then did the same with the laundry drain, adding a P trap.
Yet the smell persisted. So I recalled reading that someone had run a hose down their vent stack on the roof. I don't remember what for, but was at my wits end, so I figured it may help me find a leak. Even though I had paid for a smoke test.
So I hooked up the hose, and started running water down the vent stack.
I go in the basement and see water pouring in right near where the smell had been. Peel back some insulation, and voila, there is a small pvc pipe completely open and allowing water to pour through.
I have attached a picture.
Wondering what your thoughts are on what to do with this?
Can I just cap it off and call it a day?

Thanks!
Blake

 

[johnjh2o]

My guess is it's a future vent to be used for additional plumbing in the basement. There were some towns when I was living up north that required future vents. Of course they should be capped. Not sure of how the smoke test was done but it should have showed up then. Glad to hear you found the source of the sewer gas.

John

 

[Brichards]

John,
Thank you for the reply. You are exactly right, because it is in the same area as other piping for an addition bathroom to be set up. Thank you for the confirmation.
The only thing I can think of with the smoke test is that, since it was behind a bunch of insulation, the smoke didn't make it through visibly.
What is crazy is that anyone else who has lived here must have dealt with the same issue, but never found the source. If they even looked...
The other great part is that, after 3 years of trying to solve this issue (notice my membership date here), I found the root cause on my birthday!
Great birthday present to myself!
Thank you again everyone for the help!
Blake

 

[johnjh2o]

Happy birthday Blake.

John

 

[Brichards]

Thank you John!