Septic Tank Question

blackeyes

Hi All,
We have just moved into a new house. There is a concrete septic tank half way down our garden which is about 2 inches higher than the grass. There are 2 holes in the top of the concrete on either side of what looks like a square hatch. These 2 holes are currently covered with two large stones.

Our neighbours septic tank is visible from our garden and has what look like 2 pvc drainpipes sticking out the top of their septic tank holes. I was wondering if ours should have the same as I'm sure that having 2 large stones covering these 2 holes is dangerous?

BE.

ART6

Old septic tanks had a sloping chamber with a land drainage pipe that extended out to drain off the water from the tank. The sewage entering the first stage of the tank would decompose anaerabically and release sediments that collected in the sloping bottom, leaving the liquids to drain off into the ground. For the liquids to drain off a vent pipe was needed to let the air and methane gas out. So such a tank needed two pipes -- one to let the gas out and one to couple up to a tank emptier vehicle. Some old installations relied on the emptying tanker driver taking a slab off the top of the tank, but there still needs to be a vent pipe somewhere.

Methane is a glodal warming gas that is many times more effective that carbon dioxide, so be wary. Gormley and his bike will be after you soon enough:)

Avns1s

Assuming that your septic tank is working ok, you could simply fix two of the plastic grids (the ones you use at footpath level where your waste pipes drain). These two openings are simply to vent the tank. The emptying is done through the square slab / manhole in the middle. They normally extend upwards to prevent any rainwater / groundwater getting into the tank.

There is no real need to do anything by the way, but the grids will prevent a childs foot getting caught in the 4" opening. The removal of the stones will remove a trip hazard.

blackeyes

Thanks guys for the info. Got 2 plastic grids yesterday and fitted fine so now at least we don't need to worry about the cat disappearing into the septic tank or me tripping over the stones!.

Good stuff :-)