As used in this part, unless the context otherwise requires:
(1) “Contaminant” or “contamination” means any health-related physical, chemical, biological, or radiological substance or matter in water;
(2) “Person” means any individual, partnership, firm, corporation or association, or any employee or agent thereof; and
(3) “Water treatment device” means any product that: Is designed to alter the chemical or physical properties or characteristics of drinking water or plumbing, or which the seller, lessor or renter claims can alter the chemical or physical properties or characteristics of drinking water or plumbing; and
(4) Is used or sold, leased or rented for use on residential property.