(1) Except as permitted in Sentence 7.1.5.3. (3), an outlet from a non-potable water system shall not be located where it can discharge into,
(a) a sink or lavatory,
(b) a fixture into which an outlet from a potable water system is discharged, or
(c) a fixture that is used for a purpose related to the preparation, handling or dispensing of food, drink or products that are intended for human consumption.