Is it normally necessary to provide a separate vent pipe off a sequencing batch reactor type aerobic treatment septic tank? Or is it only required with particular systems and or construction situations?

Yes, I believe all septic tanks will produce methane that has to be vented. With traditional systems the pressure is often relieved via the vent pipe connection with the input sewage pipe. However, with some of the pumped air aerobic treatment systems, it appears that an additional vent pipe is required off the third compartment to relieve the pressure from the pumped oxygen supply.

I guess, what I'm wondering is; are there are sequencing batch systems which will allow venting, directly via the input pipe, or do they all require a separate vent stack off the third chamber. I've been looking at a Fujiclean domestic treatment plant and the technical literature seems a bit unclear... Possibly, I'll be able to simply connect a pressure relief pipe from the third chamber to the already vented input sewage pipe? I'm hoping to avoid installing an extra vent pipe on the roof.

I appreciate this is a bit of a specialized area, but I just thought I'd ask. Sometimes other people may have come across the same issues.

Thanks for any ideas.

P.S. The heavy clay that I'm building on means that a soakaway field isn't possible and I'm required to discharge directly into an open water source... hence the need for a full domestic treatment plant.