Hauling in clay dirt is a good option. Blue clay is the best clay IMO for sealing ponds. Very tight, dense, tough stuff. Sometimes it is difficult for smaller bulldozers to peel it out of the bottom. When compacted it seals as tight as clay can seal; some say almost like concrete. Pond builders in my area love to find and work with the blue clay for pond sealing. For a mini-pond I would prefer a clay layer of minimum 12" and better 24" thick. For insurance I would spray/mix/blend-in perma-zyme prior to compacting the clay lifts or layers.
Last edited by Bill Cody; 02/27/15 08:07 PM.
