I am NOT an expert, but there have been numerous cases reported on Pond Boss where digging up a pipe through the dam has subsequently created a leak through the dam.

IMO, it is easier to compact everything together as you build up the dam. When you cut through the dam to replace a pipe section, it is difficult the knit and seal your compacted back fill to the original dam material.

I will now speculate on a second topic for which I am NOT an expert! If your construction guys did a pretty good job on back filling and compacting after the pipe job, you may be close to achieving a seal. Based solely upon my reading on Pond Boss, the sealant technologies do have a good chance of success when your leak path is "almost" sealed.

You might try contacting TJ about his products (read some of the sealing threads for his info). He is also one of our best leak experts.

As for your leaky berms near the creek, I suspect it would be much less likely to fix your leaks cost effectively with polymer. Once you have enough rocks in the fill to create point-to-point contacts between the rocks, then that material can NOT be sealed by compaction equipment. The rocks effectively spread the compaction force and protect the underlying material from being sealed.

In those areas, after you get past the mixed clay-sand-rock layers do you get down to good, clean clay? I have contemplated a similar project on my farm, and wondered if you could get a cheap seal using a pond liner? For a shallow berm, you could do 6' wide roll of liner up to some significant lengths with no seams. Cut a steep wall with your equipment and then anchor the bottom edge of the liner in the clay layer and then anchor the top edge at the surface. I think that might create a very effective 3' tall berm that would be perfectly sealed.

Just thinking out loud about your problems. Good luck on your fixes, and have fun duck hunting this season!