I need a couple things that are not on the market yet.
1. Pre-trained/experienced shovels
2. I need both a right and left handed pipe stretcher, the universal ones are no good. I can't find them anywhere on the market.
3. Gas power wheel barrow would be nice.
That's all I can think of for now.
Not sure there is a max. I seen a few sewers going down a hill at 45 - 30 degrees, Or even vertical.
I believe that reference is primarily a civil criteria. It is referring to horizontal piping(less than 45 degrees) And apparently it is related to limiting the Maximum velocity due to the concerns you mentioned about the liquid leaving behind the solids. I've seen references to max velocities being limited to anywhere between 10 degrees all the way up to 15 or 20 degrees.I have never understood maximum drop. Somebody please tell me how to get from top floor to bottom floor with drain. And not exceed the maximum? Whatever a maximum is. So many have tried to explain how water can outrun solids. But I run a plumb straight vertical pipe. Is that maximum? And newton says gravity acts equally on every object. The maximum really only apply to a vented arm over. That I know of. But if everything behind your slope is vented then let it fall.