Sorry I didn't get back to ya' sooner diesel, been at church
First off, are you sure the septic tank isn't full?
The first thing I check when I go to a house on a septic system is the tank to make sure it isn't full before I start to snake lines.
Possible causes of the low water level and bubbling are usually:confused2: one of two things: A) Partial blockage of the main line. B) Improper venting.
A) If the main line has a partial block, and a steady stream of water hits it, the water slowly backs up the pipe, filling it up. (remember, water rises level) As the pipe slowly fills up, some water seeps past the blockage creating a vacuum which pulls trapped air and water behind it.
Think about a gallon jug full of water. If you only turn it up just enough to let a little flow of water out, the stream will be smooth and steady because you are allowing outside air to be pulled into the jug as the water drains out. (As long as the flow of water does not exceed the diameter of the outlet of the jug.)
If you turn it all the way upside down, it will gurgle and bubble as the water drains, because it's only pulling the "trapped" air in the jug along with the water, creating a vacuum inside the jug. (Notice how the sides suck in when you do this?)
This same principle is at work in your drain lines. As long as the flow of water does not exceed the diameter of the drain pipe everything flows smoothly. If that flow exceeds the the inner diameter of the main drain pipe, it creates a vacuum and pulls the trapped air between the blocked water and the toilet, causing the water in the toilet bowl to bubble and eventually get sucked out.
B) All drains have to have some type of vent to allow outside air to enter the drain pipe to prevent the very things I discussed in example A.
If you take a straw and stick it in a full glass of water, then plug the end of the straw with your finger and pull it up out of the water, the water will be held in the straw by the vacuum you've created by plugging the top. When you lift your thumb and allow outside air to enter the straw, TA-DA
, the water flows out!
Same principle with plumbing drains. The vents sticking out of the roof allow outside air to enter the sealed drain pipes, preventing a vacuum from being created inside the pipe. If one of those vents becomes partially/fully blocked this can also cause the gurgling and bubbling of a toilet.
Based on what you're telling me, I'm thinking A) Partial blockage in the main line between the house and the tank. Hopefully you've got a cleanout to access the line, (I believe you said you did right?) Get a reputable plumber/drain cleaner to come out and snake and clean the line proper. I say reputable because just like any other service trade there's good ones, and there's bad ones out there who will try to rake you over the coals
I would wait 'till reg. business hours to call as most charge extra (time and a half) to come out on weekends/after hours.
If you've got dirty water (sewage) bubbling up out of the concrete, then I'd say there's definitely a problem with the main drain pipe under the slab. (Either a cracked or damaged pipe)
Per plumbing code, sewer drain lines are sealed (PVC is glued) together to prevent raw sewage from contaminating soil and groundwater so you should not have dirty water coming up through concrete unless something is leaking heavily or broken.
It is possible that the water could be leaking around the toilet flange and wicking into the trench line and then bubbling up through the concrete, but I've never seen it.:confused2:
Now having said all this let me write a disclaimer and say that without seeing the problem in person I can only speculate as to possible causes and solutions
. The last thing I would want is for you to spend a bunch of money based on my info and not get the results and solutions you're after.
Let a plumber you trust check it out and give you a second (or even a third) opinion.
Hope this helps and if you've got any more questions, let me know...Dave:thumbsup:
