Anybody know to "seal" a dirt pond?

[FTG-05]

I'd be careful as well Sodo. Here in TN, a "farm pond" is one that is defined by less than 20' high dam or less than 30 acre-feet. No permits required unless you're damming up a creek or stream or something like that.

I would think in your case, if the pond doesn't seal over time, I'd try the inexpensive options like kitty litter, cement, plastic sheet etc. before I'd spend a bunch of money on bentonite or redoing the pond.

Hiltz, yea we heard you about the cement. How do you apply it, how does it work to seal and, most important, how effective is it?

Thanks,

 

[calman93611]

Bentonite comes from only 2 or 3 sources in the US and has to be shipped. For me, to effectively handle my pond, I would need more than a few dump truck loads. For testing, I did locate an ag supplier about 150 miles away. He only had a limited supply but I managed to get close to 1000 lbs in 40lb bags. It does work and, for a small project, might be an affordable option.

I believe, in my case, it will make more sense to locate some local supply of decent pond clay and have it hauled in.

I don't remember the application rate but it was nowhere near 1-3 lbs/sq ft. I think we used less than 1,000#s and used it for a pond/lake about 350-500 feet long and about 80 feet wide. So that is what? 40,000 sq ft. For the sake of argument, let's say we used 4,000 lbs, that is still 1/4 lb/sq ft. We did this about 25 years ago so it is what my memory recalls.

 

[KiotiKowboy]

I'm guessing the floor area to be around 13K sq ft., with application rate of 1-3 lbs per sq ft. So, we're talking 13K - 39K lbs of bentonite. Quick price check shows about $300 per 1K lbs. Comes to somewhere between $4K & $12K - before any labor and/or shipping costs. Not cheap.

 

[xzcVAbc5]

When you put the bucket in you said you moved the bucket around to make a soup, did you try smashing the bottom with the bucket?

Maybe squeezing the dirt will help make the bottom to stick together.

 

[Hiltz]

Yes you did, that's a reasonable $ to spend on this, if it doesn't seal (or saturate) on its own. Will the cement sink to the bottom if you pour it in or do you have to mix into the water and it settles?

All you do is spread it across the top. It sinks on its own and seals pond.

 

[Sodo]

When you put the bucket in you said you moved the bucket around to make a soup, did you try smashing the bottom with the bucket?

Maybe squeezing the dirt will help make the bottom to stick together.

Ya know? That would have been a good suggestion but I was in soup mode at the time thinking what I had to do was make a slurry. Also I didn't want to disturb or liquify my dike, it was only hours old. Can't really see what the bucket is doing in a slurry and I ain't that good.

If just pouring a bag of cement around the edge will do it that seems reasonable. Not sure I'm really understanding the cement thing though. Is it doing the same thing as bentonite, creating a self-healing goo? Or does it create a 'hard' membrane that can crack or get holes in it, for example if a deer steps in the pond?

 

[roadhunter]

I have a pond sealing project going right now. We are needing to get about 23% for optimum moisture and achieve 95% compaction. We have had 6 inches of this compacted clay material under 55 psi for over 2 weeks with no seepage. This pond was only about out 3-4 ft deep so we have excavated about 12,000 yards of material and are using about 2,500 yards of liner.

 

[newtooblue]

if you can get some clay soil ,blue clay is the best, dig it bigger and deeper and line it with a foot or so of the clay soil, that it how bigger ponds are built

 

[Sodo]

The "3 weeks later" report.

It appears that the pond has sealed & saturated itself, as best as I can tell. I didn't do anything to seal it other than churn it into soup with the excavator bucket (twice). The little waterfall flowing out looks about the same as the waterfall flowing in. I'll take some pics in the springtime when things green up.

 

[Sodo]

Pond still doing fine with no added sealer. Creek water in - creek water out (as best as I can tell.) But it's just a little pond 7 or 8 feet across, 2 feet deep. The reason I worried about it is because my creek disappears into the ground in several places, then re-appears later.

Possibly I have clay in my soil, when it rains and you walk on it you get about an inch taller, and a vehicle cannot even move if driving on it.