Sewage ejector - Wet Vent?

House inspected had sewage ejector pump for basement bathroom. The sink drained into a PVC pipe that went into the top of the pump’s cover. This is reserved for the air vent, usually see waste lines under the slab into the sides of the pit, not the cover. This same PVC line was run alongside the wall about 20 feet away and up and vented outside.

  1. Can you use a ‘wet’ vent for this sewage pump. Correct me if i am using wrong terminology on ‘wet’ vent - pipe used for air vent and liquids. No solids.
  2. Also has washing machine draining into it - allowed? I dont think so with this set up since its not sealed where washer hose goes through lid

No, methane gas is combustible and can be explosive. :shock: