(1) "Public water systems" means systems for the provision to the public of piped water for human consumption, if such system has at least fifteen service connections or regularly serves at least twenty-five individuals. The term includes systems that are owned or operated by private, nonprofit entities, as well as:
(a) Any collection, treatment, storage, and distribution facilities under control of the operator of such system and used primarily in connection with such system; and
(b) Any collection or pretreatment storage facilities not under such control which are used primarily in connection with such system.
(2) "Supplier of water" means any person who owns or operates a public water system.