Welcome to the forum! If you can dig the pond to the size that you want, plus 2', I would bring in clay, and compact it with a sheepsfoot roller in 6"-8" lifts until you have a 24" thick layer of compacted clay over the shale.


www.hoosierpondpros.com


http://www.pondboss.com/subscribe.asp?c=4
3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).