I had to repair a leach field system. A previous "contractor" - probably not licensed or knowing what he was doing, put in their leach field a couple years ago. He put infiltrators in with 3 feet of slope from top to bottom. You can see the inspection pipe sticking up to the right on the first picture. It was building so much pressure it was blowing the inspection pipe out of the ground and running down the hill.
(https://i35.photobucket.com/albums/d184/glennkangiser/P1000385.jpg)
I put the new line in - set with a laser - about 2" of slope over 100 feet.
Trench is a bit wide since I had to dig it with the Bobcat and I had to do a mound on the last 10 feet due to rocks but my Bobcat is big enough it digs as fast as a backhoe and fill is easily put back in gently 1 cubic yard at a time. It goes very quickly.
(https://i35.photobucket.com/albums/d184/glennkangiser/P1000388.jpg)
I hooked to the end of the old system so they could still get a bit of use from it. Top soil usable for leach fields in our area is scarce.
Nice...I wish I had a Bobcat too.
Everyone should have one, Tony. :) Total travel, digging - installation, material acquisition, hookup and cover time was 17 hours.