Any application under this article shall demonstrate the availability of public sewer and public water; provided, however, if the Township and/or the owner of the public sewer system determine that public sewer and/or public water is not available or will not be available to serve the project within 18 months of the date of the application, the project shall be served by an alternative sewer system and/or water system, subject to all applicable federal, state, county and Township laws, regulations and requirement. In all instances, the proposed method of sewage collection, conveyance, treatment and reclamation shall be consistent with the sewage facilities plan (537 plan) of the Township applicable to the area within which the project is to be located. The sewage facility shall be situated on the project site and must be owned by the applicant or a homeowners' association, and maintained by a licensed and qualified sewage contractor. Unless sewage disposal is entirely subsurface (e.g., drip irrigation shall be deemed subsurface, but spray irrigation shall not be deemed subsurface), no sewage facilities, systems, treatment or disposal may occur in any required open space area. A public water system and/or sewer system shall be considered available to a project if such system is located within 500 feet of any boundary line of the tract on which the project is to be located.