The existing cleanout is above ground and I have been using it for about 2 years. The way it's laid out is perfect as it's a foot down grade from where I can run it to the corner of the house but at the soil surface. it's also about 3' away from a hose bib. I think I can simply screw a 90 into the existing cleanout, run a straight piece of 25' of 4" SCH40 pvc at 1" over 4' tied to the exterior wall of the house, another thereaded elbow up, and screw in the cap. It will be about 2-3" below my wet bay. So, if I do this right, should be able to pull up, unscrew the cap on the run, hookup, dump, and put the cap back on. Easy.
BTW, we are not tied to city, we have our own septic and drain field. We are on 6 acres on top of the mountain with a nearest neighbor about 1/4 mile away. I don't think I am going to even bother with a permit. Although the straight PVC will be connected, I plan on threading it at both ends so I can remove if I ever choose/need to.