We are reclaiming an old pond which is full of alders and will need
something to plug up the bottom of the pond. Our neighbors' ponds slowly
drain throughout the summer so we probably need something to seal the bottom
and would like to avoid having to buy a huge piece of plastic (future
garbage). Does anyone have any experience with or information about sealing
large ponds with bentonite? If bentonite is a good way to go does anyone
have any leads on where I might find some in western Washington?