Is it possible that alum could be responsible for stopping or slowing down a leak?
While applying alum (via a trash pump) to clear my turbid water, I noticed how the clay particles were clumping together and sinking (like I've read about here). It then dawning on me that just maybe if I sprinkled it along the shore where I suspect the leak to be it might have an effect.
A week later I went and got another 50 pound bag of alum and sprinkled/casted it along the shore where I suspect the leak to be instead of using a trash pump to mix it with the water. About 2 weeks later I noticed about half the water loss per day and there is no longer any standing water behind the dam. Went from losing ~.5 inches/day , ~.25 overnight -to- ~.3125 inches/day and ~.125 overnight. All this while the water level is 3 inches higher....not lower.
I applied alum with the trash pump last year (before the pond was re-constructed because of the leak) and never noticed any difference in the leak. I also tried a couple of tons of bentonite with no luck last year. Makes me wonder if I'm just one of the lucky ones where the leak is slowing down/stopping due to natural causes or maybe some of the alum got sucked into the ground and help things start sticking together and clog up.
I've seen a few different posts about applying alum and some say that it is not affective when just sprinkled in the water....others say it doesn't matter.
I've emailed my local NRCS office and asked the guy who dug the test hole in my dam (to find the leak) what his thoughts are and haven't got a response yet. He did tell me after digging the test hole, that I had perfect soil/clay and the leak may eventually seal itself but because my dam did not have a core trench it would be impossible to know for sure.
Wish I knew for sure what is slowing/stopping the leak. Still makes me wonder as this is a big and fun challenge
