Saturday, June 18, 2011

Raiders of the Lost Septic Tank

All I need now is a fedora and a whip!  After much digging, we found the top of the septic tank, and moving westward towards the cleanout pipe, we found the lid.  It strikes me that there must be a reason that the lid is buried, but all I can think is that the goal is to prevent freezing.  The temptation is strong to put a steel pipe section around the lid so that next time we don't have to dig up so much soil.  But perhaps there's a reason that it needs to be covered.  Remember that we get months on end of snow and below freezing weather.

UPDATE: I'm told that a riser pipe, which brings the access port above ground level, is what I need--there is not a requirement that it be covered with dirt.  I suspect that this will be expensive, since it will involve mating the riser pipe with the septic tank.  I think the pipe around the lid to keep the dirt out will be the simpler and cheaper solution--I just need a 26" or larger diameter pipe, steel or PVC, about two feet long.


  1. Congratulations. I was going to suggest gently pushing a long piece of metal into the ground until you found it.

    The lid doesn't have to be buried, but to code and for freeze line it is always well below ground level when laying directly on the tank. You need to get a riser pipe. This is a piece of pipe larger in diameter than the lid hole that can be cut to the height of the ground level and then have a lid over it on the surface. I put one in after having to cut out a section of sidewalk (yes, the builder buried/covered the lid with a very well done job of concrete work!). I have never seen the riser pipe at the home improvement stores, but I would try them (I ended up buying one from the septic pumper that also had to put in a cleanout for me and paying too much money--darn overcharging plumbers--was too busy at the time and couldn't find it in the stores). I have seen the risers online and in the yards of some of the plumbing outfits (along with the stacked supply and waste line pipes, etc). This is a plastic corrugated pipe (with no holes of course except for where the lid sits and comes with it's own plastic lid. Let me know if you can't find it and I'll get you more info.


  2. I should add that it amazes me when the tank lids are buried (or worse covered with concrete like mine was). I imagine some building codes and maybe newer codes don't allow it being buried since that results in tanks not getting pumped until they overfill and backup into the house or ruin the drain field. Mine was put down in '68 so not sure if the code has changed (I'm in Boise, though I have noticed most, if not all newer jobs do have the lid set on the surface. Maybe it was a conspiracy to charge more money because a hole has to be digged to pump the tank.

    A few years ago we got the sewer line down the street. Several people had ruined their systems and the city won't issue permits for new tanks or drain fields so if it fails you have to hook up to sewer. I've seen quotes up to $14K to get everyone thing done and hooked up. I'd dig the trench by hand with my fingers if I had to before paying all of that for hookup (the price for just the hookup was of course many thousand without the digging and pipe work). Needless to say I baby my system since the bad economy has made money tight...

    With careful use I have found that I can probably go at least 5 years between pumping--my last pumping was after two years and it didn't need it, but since I had the guy check it--key is checking the solids level--(don't put the wrong things down there and limit how much goes down in a 24 hour period). Kids with frequent toilet flushes and long showers, lots of laundry loads in a day and harsh chemicals, food stuffs, etc is a no-no!


  3. I understand, from classes I've had, that water meters, at least, need not be covered to prevent freezing. They need only be placed below the frost line. The heat from the surrounding soil will keep them from freezing. (This is a bit of book learning that I don't expect to need in Los Angeles -- unless, that is, we actually are scheduled for an ice age in the near future.)

  4. Clayton,

    All you need to be concerned about is the riser pipe mates to the tank lid top so that water/dirt can't enter and that the new lid cap/cover also doesn't allow anything to enter and traps the unpleasant (and toxic) sewer gasses. The tank is at or below the freeze line. The tank surface around the pipe up to ground level is of course covered with dirt (only the cap lid remains exposed). You could probably use any pipe that is large enough diameter, but finding/making a suitable lid that keeps things out/or in may be a challenge without using a pipe that comes with its own lid (or is designed for the lids). The caps can also be secured or locked so that children, etc can't open them up (if that is a concern).

    My installer just set the riser pipe on top of the tank (I would have preferred it be glued or bolted to the tank, but I haven't any problems since it was done 4.5 years ago). If you do a web search you'll find lots of examples, images, and options of how to do it.

    You'll be glad when you get that done since it makes maintaining and tracking of the condition of the tank (and pumping the tank when needed) substantially easier.

    Is your tank concrete or fiberglass? Just curious. Either one works just fine.

    Good luck.


  5. Hi. I inspect septic systems for a local government in Texas. So I don't have any experience with cold climate systems. There should be a supplier in Boise. Or google septic tank riser. Or go here; Main thing is don't put any grease or garbage disposal into the septic system.

    Good luck

  6. Consider using sections of concrete pipe. Years ago I had a similar problem and solved it with a 24" long section of concrete pipe 24" in diameter, which allowed direct access to the tank lid. I excavated a 36" diameter circle centered around the lid, cleaned the top of the tank and set the pipe in a mortar bed to seal it to the tank, and carefully backfilled around the exterior of the pipe. Because the concrete pipe section is "stepped" at both ends (one male, one female) to allow joining additional sections, a lid was available to go on top. In my case, this worked perfectly, because it put the lid 8" below grade, where it couldn't be seen. I still had to dig that 8" every few years for pump-out, but 8" beats almost 3 feet, and probing for something you know is 8" down is pretty easy (a little triangulation measurement from reference points on the house locates it rather exactly). One 24" section of pipe isn't so heavy that two people can't lower it into the hole; the trick is to make some "handles" with 1/4" angle iron that hook under the lip at the bottom of the pipe and attach rope to them. 4 "handles" in pairs, at 9 and 12 and another at 3 and 6 o'clock, wedged into place with an X made from pieces of 2X2 allow control during lowering. Set the pipe on 2X4s over the hole, two people pick up the pipe, a third slides the 2X4s out, and lower away.

    Concrete pipe is available in a variety of diameters and lengths; if you go bigger than 24" diameter or longer than 24" you'll probably need some sort of mechanical assistance to lower it.