(1) Where gravity drainage to a sanitary drainage system is possible, a floor drain shall be installed in a basement forming part of a dwelling unit.
(2) Where gravity drainage to a sanitary drainage system is not possible, the floor drain required by Sentence (1) may be connected to a storm drainage system, dry well or drainage ditch provided it is located where it can receive only clear water waste or storm sewage.
(3) A floor drain shall be provided in a public laundry room, garbage room, incinerator room, boiler or heating room that is not located within a dwelling unit.