Pond Boss Forums POND CONSTRUCTION Soil questions leak in shale

we put a pond in last August and it has been a slow go filling up. I have read some idea's here but ran into a find yesterday. The pond, for the most part, is clay with a little bit of shale mixed in. When the water hold in the part of pond it has a clay bottom look. A couple weeks ago I hand threw in some beneidite to an area that had some small cracks for the hell of it. Seem to raise the level. Yesterday I had a lot of water going in and the level wasn't getting any higher so I walked along the edge and saw a area where you could see the water flowing out. So I investagated and it was an area about the size of my fist that was pure shale. I cleaned it out and poured beneidite in it just cause I didn't have time to do anything else as I was leaving in about an hour. I noticed in an hour the water level going up. There is an area about 50 ft by 50 ft that has more shale than anywhere else. It is mixed with clay but I'm sure could have some pockets like I saw. My question is it okay to just spread dry benedite all over this area or should I till it and mix in the benedite. Of course anywhere there is not clay I can throw some in and mix. Also is this a decent solution. Thanks in advance for any input as this is my first experience trying to find any leaks. Agian not sure there will be anymore but like to nip it while it is easy to get at...thanks

It should be tilled in if possible.