Drywell for washing machine questions

Planning on making a 55 gallon drywell for our washing machine, to take load off septic leach field.
Questions:
1. The 1" washing machine discharge hose just sticks into a larger pvc vertical pipe, in the wall, where I assume there is a trap. Is the vertical pipe necessary? Would it be a bad idea to clamp the outlet hose to a 1" pvc pipe, to get the water to the drywell? Should I put a trap in the 1" pipe? Not sure of capacity of washing machine pump. If, as planned, I drilled the hole, for the pipe, thru the wall, to the yard, close to floor level, and with the 1" pipe pitched toward the drywell, I think there shouldn't be much load on the pump.
Instead of pumping the water up about 2' it will be pumping it slightly downhill, thru a 1" pipe, about 20'.

2. Ideas on venting?
I think with the machine outlet hose clamped tight to the 1" pcv, I should put a vent in the system.
Any ideas? Rather not have something sticking up out of lawn.
Thinking of a small studor vent, in the pipe where it will come out of house.

3. Overflow
Not sure how to do this, without having something the mower will hit.

4. Filter. Any recommendations here?

Any suggestions, concerns, ideas? No code thoughts needed.
Thanks

Should do it similar to a washing machine arrangement.
Standpipe with 1-1/2" or 2" trap and a vent pipe few inches downstream of trap, with an AAV(Air Admittance Valve). All exposed.
It's a gravity system from the standpipe out to he drum.

Overflow? How deep will the tank be. Where would you want it (or not want it) to overflow? Possibly a buried overflow to a point away from mowing and where it can be raised a to the surface. With a removable, course screen, perhaps to keep small critters out.

I really don't think a 55 gallon drum will last very long.

Of course you'll have the existing standpipe, that goes out to septic system, to switch back and forth to when and if the 55 gallon drum overflow system gets out of hand.

Thinking if the drywell backs up, and using a stand pipe, it would flood the garage. If using a stand pipe, I think I would need at least 1 1/2" pipe from stand pipe to drywell.

55 Gal drum is plastic.