Hello! I constructed a small (1/3 acre, 11' deep) pond in Kansas and it leaks. It is a pit pond (no dam). I was advised to till in salt or soda ash and then compact. I've researched this method and it seems to be a common solution in my area. Alternatively (but more costly) there is a local source of red clay (90%) that I could have brought in to create a 1' thick liner. The clay would be installed in 6" lifts and compacted after each with the tires of a 50K lb high loader.

My question is this: Should I do both? I really dont want it to leak again, but I'm not sure if the salt tilling + compaction + 1' clay liner would be overkill?

Thanks!

I for one have never heard of salt or soda ash for leak fixing. I'm interested to see if anyone has experience with it.

From that perspective of ignorance, a properly installed clay liner would do the trick. If you can't get good solid evidence for salt/soda ash, I'd go with the clay and get it fixed the first time.

^^ I believe Snipe has used it with good success.

Thanks guys, I appreciate it. I am going to do the clay regardless, I'm just deciding on doing the salt as well, or if that process is an unnecessary expense when the clay will likely fix the issue.

Yes, Snipe has used soda ash with good success. I was able to speak with him over the phone about it and he advised me on the correct application process. The CL- in the salt or soda ash breaks the + bonds of the clay particles if I'm not mistaken. Sometimes clay particles (having + charges) can actually repel each other and then the soil structure behaves more like a porous soil than a fine clay. The salt/soda ash destroys that soil structure, allowing clay to be compacted and seal. I was going to do this method first as a base, and then have 1' of clay liner installed over the top. It's starting to sound like overkill though, and I may just do the clay.

Here is a link and the specific Q&A from the Kansas agronomy website:
https://webapp.agron.ksu.edu/agr_social/eu_article.throck?article_id=1762

Q: Can you add materials to help seal a pond?

A: Dispersants such as soda ash or rock salt are used for sealing lagoons or ponds. Dispersants work by causing clay particles to swell and repel each other, thus destroying soil structure. All dispersants are to be incorporated and compacted in six-inch layers during the construction. It should be noted that adding the dispersants to an existing pond may not work. It will likely be necessary to drain the pond, clean out the sediment, scarify the bottom of the pond, add the sealant, and then compact the pond.

Soda Ash

Application rate: 10-25 lbs/100 sq. ft.

Notes: Makes a good seal. Soil must contain >15% clay, and >50% clay + silt

Rock Salt

Application rate: 20 to 33 lbs/100 sq. ft.

Notes: Least expensive. (One reference suggested rates as high as 400 lbs per 100 sq. ft. during new construction would not harm fish or inhibit vegetation).

Nick,

You never gave any details on the initial construction of your pond.

What was the clay content of your pond material? How was it compacted? Did they compact with the material near the optimum water content?

If your pond has decent to good clay, but it was not compacted correctly during initial construction, then you might fix the leak just with improved compaction.

If there was decent compaction and you only have small leaks, then amending your current pond material, then disking it into the soil, then compacting again might work.

My rental rate down here on a Cat CP563 (84") vibratory padfoot roller is $743/day. That machine is capable of compaction much greater than a heavy wheel loader.

I am asking a lot of questions, because I suspect I will run into a similar situation when I construct my new ponds!

What is your bid for trucking, spreading, and compacting the clay for the liner?

The other option (if you are only leaking a little bit) is to look at the Soil-Floc polymer sealer. If that is potentially feasible for your situation, then contact Teehjaeh for a cost estimate. He is not too far from you (Lincoln, NE). That might be a cheaper fix than trucking in the clay liner.

Good luck on getting your pond sealed!

FishinRod,

Sorry for the late reply, to answer your questions without being too long winded:

1) Initial construction: Small 1/8 acre pond dug that wasn't compacted at all, but bentonite was worked into the soil and it held great...stayed full approx 1-2 years. Unfortunately the banks partially washed in after a couple of big rains and it looked terrible on top of being smaller. Paid to have it cleaned out and decided to go bigger (1/3 acre) and deeper (11') at that time. Again, no compaction, I thought I could put some bentonite in it and things would be fine. I WAS WRONG, lol. The pond leaked and we drained it. I have no idea about the clay content of my site.

I elected to do the clay liner. I had about 500 tons of red fill/clay brought in, installed, and compacted in two 6" lifts for a total of 1' of material.

*Cost of material+trucking was $6.50/Ton
*I paid them by the hour to run a huge case loader spreading it all out and driving over it while the did. I was into them for about 9 hours of their time.
*I also rented a vibratory sheepsfoot (on recommendation from teehjaeh57-he told me to insist on this)

If this fix is successful, I'll make a post detailing everything...hopefully I'll get to make that post lol.



Side note:
I'd like to thank teehjaeh57 for all of his guidance. He doesn't know me at all, but took multiple calls from me (for free) and gave me very valuable advice. Additionally, he could have recommended that I buy polymer from him (and I likely would have), but he told me that he thinks my clay liner should be enough to do the job. Honest, stand-up guy for sure. If I do wind up with small leaks, I'll likely contact him and apply some of his polymer as a "plan B" to my clay liner.

Hope to be posting soon and thanks TJ!

Nick,

That sounds like a good effort. Fingers crossed that you have now fully sealed your pond.

I think I will have sufficient clay at my pond locations, but I am going to have to come out of the bottom of the pond with some lifts of sealing clay over some sandy layers at slightly higher elevations. My plan is very similar to what you performed on your pond!


P.S. TJ has LOTS of pond sealing experience, taking his advice seems to be the correct course of action in most circumstances. If your pond is mostly (but not perfectly) sealed, then he might be a resource to perform a Soil-Floc treatment if recommended.

Good luck having a nice sealed and water-filled pond in your near future!

Thanks!

Great meeting you, Nick, and I'm glad I was able to help. Hoping for some good rains your way to fill that pond and find it sealed!