Thanks Ben - just to update we have done a half day testing using a heavy-duty pile lifter to see if we could remove the contaminants dry - works brilliantly - so no need to get it wet at all - we probably have to do about (in total) 40% of the area of a single court - the main ingredient is time as to get it back to green condition we were doing multiple passes and are having to remove a lot of the contaminated sand which will have to be replaced with fresh - so its not a small job by any means. It will keep me and my son busy for a couple of days at least! Very awkward situation as well surrounded by trees and grass with no hard paths etc - I suppose one of the big contractors would just cut the chain link, drive a mini tractor onto it and then repair the fence again afterwards. Its nice work in this weather anyway!