Adds facilities and infrastructure of water purveyors to the list of essential public facilities delineated under the Growth Management Act (GMA). Changes the definition of "water purveyor" to an existing definition that defines a "purveyor" as any agency or subdivision of the state or any municipal corporation, firm, company, mutual or cooperative association, institution, partnership, or person or any other entity, that owns or operates a public water system. The definition also includes the authorized agents of any these entities; modifies the proposed addition of "facilities and infrastructure of water purveyors" to the list of delineated essential public facilities in the GMA to "facilities of Group A public water system water purveyors serving 100 hundred or more connections"; and defines "Group A public water system" for purposes of the previously mentioned addition by cross referencing an existing definition..