Each fixture will need it's own trap even though you have a pump system.
Otherwise, the pump would siphon dry all your traps.
I'm going to install a full bathroom in my basement. I'm planning to put a sewage ejector pit behind a wall, and each fixture (wc/shower/sink) will be within 6ft of the pit. I will of course vent the pit/pump through the attic. The question is, if I make the vent wide enough for the pit/pump, do I also need separate vents for each fixture?
Ok, I understand that I need traps for each fixture, but do I also require vents between the fixtures and the pump? Since the pump is close enough to the fixtures (<6ft) won't its single vent (provided it's wide enough) equalize the pressure enough to avoid siphoning of the individual traps?
Plumbing code requires a vent for every fixture.
No plumbing code lets you use only the vent for the pump.
The reason they don't, is that is will siphon the traps.
All pump systems have instructions showing vents for the traps.
You, however can try not installing the pump and fixtures the right way, and let us know what happens.
I hope you don't sell the house to anyone though.
It would be a shame.
The pump systems can have a very bad odor if exposed to air.
Instructions for a Zoeller pump system
It's not a huge deal to vent each fixture directly. I'd rather do that than be sorry later. Thanks!