Results 1 to 5 of 5

Thread: older concrete septic tank question

  1. #1

    Default older concrete septic tank question

    A year ago I bought an older house and about 6 months later we began seeing water seeping up over the septic tank. Now it has gotten worse, we had it pumped a few weeks ago and it was fine for about 6 days and then I noticed the water seeping up again. I found the lid, however all it was was the overflow catcher from a large pot(forgive my lack of the tru name of it). We were getting a smaller amount of water seeping up from this area. Further out towards the end of the septic tank we are getting more water and I dug it up and there seems to be a seam in the concrete and water is coming up through this seam. Is this possibly a lid?

    If anybody out there could help I would really appreciate it.

  2. #2
    Join Date
    Dec 2003
    Kent, WA


    Your tank should have 3 lids -- one closest to the inlet pipe is to inspect the inlet, an there's not much to do there. A larger one in the middle is where the pump out and major inspection occurs. The third one is by the output pipe and the important thing to do here is inspect the output baffle to make sure floating scum does not go out to your drain field clogging it.

    An overflowing tank lid (could be any of the 3 with the output lid the most common one) indicates your drainfield can't take the amount of water you're sending there. If you didn't just do 10 loads of laundry, you most likely have a tired or clogged drain field (most likely) or maybe just a crushed/broken/clogged output distribution box or pipe.

    The purpose of pumping the tank is to remove the solids that sink to the bottom, or excess scum that floats on top. The tank should always have the same top level with the useful capacity reduced as solids build up and scum gets thicker. Hence the need for pumping. You should check these levels every 3 years and then pump if necessary.

    So you need to call a septic guy and have him assess the situation. Most don't bother digging up bits and pieces because they are difficult to locate (time costs money). It is typically cheaper in the end to just replace the field unless there is evidence to the contrary (or you just drove your car over buried the output pipe crushing it).
    Kent, WA

  3. #3


    You might at least want to dig up enough so you see all (three?) covers on your septic tank.

    Some tanks have two chambers with the first two lids covering the first chamber and the third lid covering the (smaller) second chamber. In both chambers the water level will rest about 6 inches to a foot below the top, although the layer of scum in the first chamber may make it hard to see the water level. When the first chamber accumulates enough solid matter to require pumping, the second chamber should also be pumped.

    If you leave the (furthest or second chamber) lid off and the liquid overflows whenever you use water in the house, then you know you have a problem somewhere beyond, say, in the leach field Observing things this way is messy with a one chambered tank since a lot of scum will come out before you see water overflowing.

    You may save some costs if you find the junction box just before the leach field and dig that up and inspect it to see if a blockage is before it. This way you can tell the septic contractor when he comes more specifically what needs fixing.

    Pumping a second time in quick succession or if there is hardly any solid matter in the tank is essentially a useless maneuver and expense.

    I'm not sure what you mean by a large pot but some septic tank systems have a dry well (aka cesspool) in lieu of a leaching field. The dry well should also have a lid for inspection and pumping out. Unlike a septic tank, a dry well drains to empty over time. (Actual cesspool systems have just the drywell, no septic tank before it.)
    Last edited by AllanJ; October 1st, 2008 at 12:26 PM.

  4. #4



    Sounds like a drain field that is in need of repair. Depending on the age of the house it might be time to replace it.

    One way to check this out and double check the word of the septic service company. Is when they pump your tank (which they will want to do in order to diagnose the drain field) make them do pump it from the outlet end of the tank. When the pump the water level down, listen for water running back into the tank if this is the case then it is time for a new drain field.

    You can get someone to do a video inspection of your lines to see if they are clogged or damaged but more then likely it is already to late.

    The only other way to test this without servicing your tank is to hold off on laundry and as much water as you can for a 2 or 3 days and check the out let end of the tank for the same problem. If it is still over full you know the problem


    JC Septic Service

  5. #5

    Default Septic Tank Problem

    The company is right. Most problems like yours are caused by the septic tank drainfield coming to the end of its life and needing replacement.

    However, it is not unusual to find that a plastic bag has blocked one of the baffles between the tanks or the outlet pipe, so before you do anything else, take the lids off and have a look. You probably won't see anything but sewage, so have it pumped out and clear any pipes, baffles etc.

    You can also buy drainfield restoring bacteria, but these only work in some cases. Worth a try though as they are not expensive.
    Last edited by joed; February 21st, 2010 at 10:41 AM. Reason: to remove the spam link

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts