Pond Boss Forums POND CONSTRUCTION Soil questions I am worried new pond being dug and hit sand

I am having a 1/3 acre fishing/swimming pond dug in front of my house. My contractor has done this for over 40 years. At the start of project he said i had great clay and not to worry about anything. He got the one end of pond cut in and as he got around to the other side of where beach is located he hit a vein of sand he said. he is probably 4-5feet down when he hit it. his plan is to dig it out a couple feet down and pack the good clay i have on top. Just out from where he hit sand is going to be where the deep end is which i am hoping to be 10 feet deep.I am worried what if he hits more sand. I sure hope it is just a small vein like he said. Seems to be a 10-15 foot area and has a little water seeping in the area.I hope he can get it sealed good since it is in my front yard.What's the possibility of digging through sand and hitting clay again?

As long as the vein is correctly sealed with good clay you will be good.. Emphasis on CORRECTLY

I agree with compacting it correctly and making it thick enough. I wouldn't go with less than a 24" layer of clay over the sand, compacted in 6"-8" lifts.

When I renovated my pond, I ran into clay at 11', dug thru it into sand, and hit solid clay at 20'-22' depth. Just not enough clay to line the pond with because I didn't want to make the pond deeper than 22' depth.

Shup why didn't you want to go any deeper than 22' just curious?

We were fighting groundwater coming into the pond, and I left the island in place, so to get to that depth the sides were getting pretty steep. We had to run the pump for about 12 hrs every day before digging just to remove enough water to dig, and keep the pump running while we ran the excavator. Also, it was too steep to get a truck in there to remove the soil, so we were having to touch the soil twice just to get it out of the pond basin. The $$ going out was rapidly increasing for less and less dirt removed.