Sludge generated during laundry wastewater treatment was compared with sludge from a municipal wastewater treatment plant. They were mixed with furnace ash and studied for pH, cond., dry residue, mineral and org. substances, P, total and ammonia N, as well as for phytotoxicity against white mustard, garden cress and barley. The plant germination was inhibited, but lengths of shoots and roots remained unchanged. The sludge and ashes were recommended for reclamation of mine dumping grounds.