Let me try this again.
I am not going over sand with plastic, and then topping it with more sand. I never said that anywhere in any of these posts.
I have a sand pocked someplace but I don't know where the leak is. We have hauled probably 2,500 yards or more of clay to the lake bed in the last few years. Except for some sand that ran into the lake after rains the last two years there is no solid area of sand in the lake bed. There is probably a thin spot someplace that lets this slow leak keep leaking.
This is not some dramatic fast leaking structure. It takes 6 months for it to leak down to the current level. In the summer time it drops about an inch a day, which is not that drastic. Every year it seems to get a little bit better, as if it is sealing itself off, even though it's doing it very slowly.
We are going to ADD MORE CLAY to the existing lake bed. We are going to level it and spread it as evenly as possible with a dozer so that every exposed inch of the lake bed will get MORE CLAY. I hope this is enough to seal the leak itself. Secondly, the addition of this clay is to displace water to reduce the downward pressure. I AM ADDING MORE CLAY TO THE LAKE BED FIRST. I can't make this any more clear.
Next I will add the 10 mil liner, which has it's own flexibility. I've already discussed this will a pond liner guy and he didn't see a problem with it. He also said the 45 mil EDPM was not necessary on a project like this. I don't think you could even install it on a project like this. I am not using 6 mil plastic. I have 10 mil. When I lap it, it will be 20 mils in some places.
We are going to use front end loaders on small tractors to add clay on top of the plastic. We will add it slowly to the edge and work our way out. We will not be dumping heavy loads of clay onto the bare plastic. We will work our way out on mats, and also use shovels if we have to. There will be no heavy equipment touching the plastic.
The plastic will be under enough clay so that a deer can't possibly step through it. There are no cows. As soon as the layer of clay on top is completed the lake will be filled from a well. The only time the plastic will be exposed is while we are installing it, and we will work it one piece at a time, leaving nothing uncovered.
I'm becoming mystified concerning the participation here. I've never said I'm using 6 mil plastic, and I've never said I'm adding it on top of a sand bottom and adding sand on top. There is obviously a spot somewhere that didn't get enough clay, but we've hauled in tons and tons and tons of clay already. All I'm doing now is sandwiching lapped 10 mil plastic between two layers of clay. I could actually leave the plastic out of the equation, but I can't see how it could hurt to add it, and 10 mil plastic is just as waterproof as 100 mil plastic, and when topped with clay it will last probably just as long.
