The sludge field from a cleaned out half acre pond likely will not cover quite a half acre. It took a year for mine to dry out enough to move after the clean out in August 2015. We spread and smoothed it a few months ago, then seeded it with annual rye/fescue mix. Now it looks like a wide grassy hump in the field below the pond. We pushed it up against the back of the dam and sloped it out from there, so now it tapers from nothing to about four feet deep to nothing. When sludge is first pushed out it will have the consistency of low slump wet concrete. When exposed to sun and wind, it will quickly acquire a crust that a man can walk on, but don't be deceived, it will still be totally mushy below for a long time.