In article et,
says...

"Chris Lewis" wrote in message

In your case, obviously some or all of your drain plumbing in the house
is _below_ the tank, hence you need the septic pump.

Whoa! Not so fast... In our area, pumps are now required on all new
installations. More on that, below.

Needing venting on the bed is a little unusual, so it might not be
exactly as described above. Might be something needed to ensure
that your septic pump doesn't overpressure the bed lines and pop
them apart.

All of our new systems have such vents, as well. Hardly unusual.

In a traditional septic system, the leach field is lower than the
septic tank, meaning the leach pipes are buried well below grade.
Great if the soils work well for that.

But in areas with high water tables or soils that don't percolate
well, the leach field can be a built-up sand bed *above* grade.
These systems require a pump to lift the sewage from the septic tank
to the leach field. Very different from a traditional septic system,
more expensive, more maintenance, but they can work in small spaces
with poor soils.

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