The best way to deal with the winter disposal of greywater issue is to put in a drain field similar to what they use to empty a septic tank. Since there will be no solids, the tank isnt needed. Just dig a trench below the frost line, preferably under where you would like to garden, and put in a drain line made from perforated pipe covered with gravel and protective cloth to keep it clear. Then when the weather demands it hook your grey water to go down the pipe. We have our set-up with a…