I first stripped out all the sod to get ready for the excavation of the pit. I made a mistake of covering the area outside of the location where the pit would be with mulch. This just made a big mess. I should have done that later but nothing like screwing up the first step to get a project going. Sigh!!!
Starting to get the hole down to the depth I wanted.
I added a four-foot base made out of 2x4s to distribute the weight and help support the first fountain.
This shows the finished pit with lawn edging around the outside and the support system in the center.
I added carpet on the bottom and around the edge so when I placed the PVC membrane, there would be no sharp pointy things to stick through. It would also allow me to walk on the membrane with cushioning, being very careful that I never had pointy things stuck in my shoes.