I am going to try to explain this issue without including a photo.

I am moving my Washer/Dryer Hookups ~ 12 Feet to another room on the 1st
floor of my house. I was in the basement last night looking at how the 2"
PVC drain would be moved. Currently the drain comes down through the floor
to an elbow just below the Floor Joists. From there it runs for 10'
pitching toward the main septic line(already tied in to the lowest point)
going out at a rate of 5 inches over 4 feet.

So my question is, what is the smallest pitch that is acceptable considering
that it is a 2" drain and that it needs to travel ~22 feet to get to the
main drain line? I want to avoid notching out the Floor Joists if possible.
Any alternatives?

Thanks In Advance,
-a12vman