Pond Boss Forums POND CONSTRUCTION Soil questions What's up wth this?

I"m hoping there are some advice givers out there that don't have a life like me except for ponding, this holiday weekend.

Well I finally got to working on the pond again after family issues and taking my daughter to college. Here is what I've done today:

1. Tilled up the pond basin and sides after a couple of weeks
of laying dorment.( Rained a couple of times )
2. Spread Bentonite at about 2/3 lbs per sq. ft.
3. Tilled in the bentonite for the whole pond, basin and sides.
4. Rented a jumping jack compactor for the weekend.
5. Started the compaction at the small end of the pork chop
shaped pond.

Compactioning is going fine until I get to the suspected leak site. Then the compactor is shaking the soil as if it were jello. Then begins to sink into the soil, I pull it out and dig a couple of shovel fulls of soil from the area. Nothing, but very loose soil, I probe the area with a rod and it sinks about 10" till I hit something soild. This is and area of about 8 feet in diameter.

Here's my question; Am I in trouble with trying to compact this pond and not have it leak again. Please repound, I going over the edge with this pond.

s_f, I have no experience with pond building, but if the suspected leak area is behaving so differently, I would think you're going to have to address it.

Anymore information of where that suspect area is relative to the whole basin? Deepest part? Sides? etc.

Can you refresh us on the size of the pond and such? Many folks might not have seen some of the prior posts while the forum is working out its bugs.

This is from a prior post:

"I thought I'd upate you on my pond re-construction. I've brought in about 2 yards (hand loaded) of blue/gray river bottom clay.
I tilled up the basin after spreading the clay and will till in bentonite and compact it with a jumping jack compactor. Then some more clay to seal off the basin.
I sure hope the weather holds until this is finished. Its been alot of work and my honey do list is behind and I hear about it daily."


The area that acts like jello is in the very middle of the basin. The pond is 80'x50'x8'deep, with a clay/sandy soil. I first put blue/gray clay at the back area because that is where we broke into the ledge, when it was first excavated last year. After dowsing the basin I located a water source about 3' from where I'm experiencing the quick sand type of earth.
I'm going to address this today with about a yard of more blue/ gray river clay, hoping that this will be enough to stablize the area? Weirdest thing to feel when your compacting, feels like you'll be swolled up any minute.

I have heard, through the forum, that when you want to cover up a suspect area, you might want to use around 2' of good clay.

Can anyone else help out here?

Just came in for a break.
Brought the tractor in the pit to add more surface area to the compaction. It is like riding on a pillow. My son has come over to help and he stood in one spot in the basin and started jumping up and down, he sank in about a foot and still had more to go. He said it feels like sponge cake.
I'm fillling the area with more good clay and compacting it with the tractor. I'm not sure I'll ever get it solid.
I'll then start filling it with water and hope it is sealed, don't know what else to do.

I think you better get a roller on it. Much better than having a leak. You may get a much deeper pond that way also. Much cheaper than starting all over. Fall will be there soon, also.