Two problems have been found. The good news is that volume has increased.
I located several high spots in the pipeline using a self leveling laser level. Air release vents were added to these locations. Just a screw in fitting with hose barb, connected to some clear tubing so we could see how high the water column would rise in the tube before stopping. When drilling at each location, a constant whoosh of air came out for quite a while before any water came out. Trapped air was definitely a problem.
One drilling location was on a bind from being raised by a root, and the pipe cracked in half on drilling. Before repairing it, we ramrodded the inside of the pipe up through some 45 deg elbows and more muddy water came out.
Flow is now double from before. I have found two more "high spots" that need to be drilled to release air. I believe even more water volume is possible.
btw I still may try a trash pump. I checked and mine is rated at slightly less than 50 psi. I will probably add a pressure gauge but probably don't even need it?
