If given a choose of the type of “natural” fertilizer you use on your plants which would you use? A natural fertilizer without any chemicals add which consist of rabbit manure, aspen shaving and vermicompost or one containing human waste, unknown chemicals, miscellaneous items flushed down a toilet or drain (storm or business)? Sludge was given the nice name of “Bio-solids” in hopes people would not realized what it is. When you purchase compost from a landfill you are buying SLUDGE. They will tell you it is perfectly safe, but if you do a little research you will learn it is not possible for all the harmful chemicals to be eliminated. Also, the Natural/Organic bags of fertilizer contain sludge. Read the ingredients before you buy. See chart for examples.