How necessary is septic tank pumping? Treatment?

[George E. Cawthon]

You need to know the depth of the tank (fairly easy to determine) and the height of the outflow (not so easy to determine, unless you can look in the tank).

The exit is usually a T (lying sideways) or an el, pointed down. You want the bottom layer at least a foot below the outlet pipe and you want the floating layer thin enough so that it won't enter the top of the tee or the el.

You can measure the depth of the top layer and the height of the bottom layer by feel. The stick will have some resistance as you push it down and then no resistance as it goes past the bottom of the floating layer. The bottom layer with have resistance and then the pole will stop at the bottom of the tank. To keep track of the depths make chalk marks on a second pole held on the ground to indicate the top of the floating layer, bottom of the floating layer, top of the bottom slush, bottom of the tank.

As a general rule you probably shouldn't have a bottom slush of more than 2 to 2-1/2 feet and the floating layers shouldn't be more than 1 foot thick for a residence size tank.

[Wayne Boatwright]

On Fri 02 Sep 2005 07:41:19p, Bert Byfield wrote in alt.home.repair:

First, find a 10-foot pole. Then stick it in the hole all the way down to the bottom. Pull the pole out and taste it. If it doesn't taste good, it's probably time to pump it out.

[L. M. Rappaport]

On Sat, 3 Sep 2005 04:03:02 -0400, "Robert Green" wrote (with possible editing):

Up here it's known as a dry well. It is basically a large (maybe 6' diameter by 20') cylinder made out of cinder block with holes in it. It is placed on gravel and there is a large concrete cover over it. It is located over 150' from both the well and septic system. That's been in place for over 30 years as well, but it's never been checked, however nothing ever seems to back up from it.

[Olaf]

I'll remember to not be eating anything the next time I visit this thread.

[Bert Byfield]

You "feel" this stuff with a ten foot pole. ;-)

[Sherman]

Actually, it will eventually back up at the exact wrong time.

For instance, you have guests in for holidays or you have guests for an event like a wedding or shower. I can guarantee that is when it will happen. So go ahead and pump it out the week before such an event.

[Lee Choquette]

I have seen a tank that was just fine when it was pumped after 15 years. The owner attributed its robustness to the fact he ran the washing machine drain directly to a separate leach line (in the desert, not in a lawn), bypassing the septic tank and therefore never pouring chlorine bleach into the tank.

Lee