Ideally you want 18"-24" of clay over the sand, packed in 6" lifts with a sheepsfoot roller.
We didn't hit clay when I renovated my pond until we hit 21' depth, so we didn't have enough to plate the pond. (the rest of the pond is sand). That is why my pond is currently down approximately 7 feet (vertically). It's a ground water pond and follows the ground water level.
Great info thanks for the reply. I'm really not sure how deep we'll need to go to hit clay. Hoping it's not much deeper than 12ft as ideally I'd like a depth of 12-15ft.
I had also planned on using all the dug material to build a large privacy berm...with the majority being sand this will throw a wrench in my berm plans unless I have enough topsoil to cover it when we scrap it off the top of the site.
