520 - 529 : WASTE DISPOSAL, DRAINAGE
520 Waste Disposal Drainage (Grouped) Waste Disposal, Drainage icon
521 Refuse, rubbish, garbage disposal
522 Gaseous waste
523 Sewage disposal foul drainage
524 Petrol, chemical wastes
525 Natural water drainage
526 Internal drainage (above ground drainage)
527 Below ground drainage including storage
528 Other types of waste disposal, drainage
529 Parts and accessories