Even with the clay layer and Bentonite, the pond leaked at least an inch a day maybe more, I ended up pushing the clay/Bentonite layer on the bottom all around the sides to expose the original bottom which was mostly sand, I did this after I took core samples and found clay 4 to six feet under the sand, for different reasons, I wasn't able to start removing the sand until recently, In this picture, I'm just getting started.
