Here is a detail view of the ground level center connections. You will note that the ground cross piece was made of two pieces joined together with a straight-line joint coupling. This was because I miscounted when I counted the number of long pieces of PVC piping that I needed from my hand written plan drawing. I was short one pipe length. I had a leftover piece of ¾ inch PVC pipe in the garage from an air conditioner drain project I had done years ago. It was for non-drinking water and in comparing the two types of piping; I discovered the differences between the two.