Connecting sewer ejector to gravity lines

I have a shop building about 40 feet from the house. When I poured the concrete I installed a Liberty sewer ejector that will handle the drain from the one bathroom. There is 2" ABS piping buried that runs from the pump to the house. I tunneled under the house foundation near the front porch, and there are two 3" ABS branches near the rear of the house that drain to the septic tank. So, I will be hanging about 35' of 2" ABS from the joists and sloping that gradually down to join one of those branches.

The unit came with a 2" ball valve and a 2" check valve. I assume that the ball valve should be located adjacent to the pump and is for use if the pump needs to be removed. Where should the check valve go? Any other comments on this type of installation?

 

coming out of the sump put the check valve then the ball valve. Then when you need to service or replace the check valve the ball valve will keep the wast water from showering you when you take the check valve apart/off.