wrote in message
...
Dear Readers,
I need to replace my main line of cast iron drain, where the house
trap and vent are. I have a septic system. Just before I was going
to purchase the PVC pipe, I talked with my neighbor (who has a pump-up
septic system). His house has no house trap and no vent. Is this
because he as a pump-up system? or is there some exception to the
plumbing code that I'm not aware of?

All advice appreciated.
-Theodore.

On your system, the house trap and vent are keeping sewer gas from entering
the waste line. Without it, sewer gas would only be prevented from entering
the house by local traps, which in some cases can evaporate if not used
frequently. If his entire house is pumped up, he has a closed, sealed pit,
with a vent. If a house trap were placed between the pit and the discharge
to the septic, the force of the macerator pump would blow the liquid right
out of it