(a) It is the intent of the Legislature that all commercial solid waste facilities operating in this state must receive site approval at the local level, except for recycling facilities, as defined in section twenty-three, article fifteen-a, chapter twenty-two of this code, that are specifically exempted by section twelve, article eleven, chapter twenty of this code. Notwithstanding said intent, facilities which obtained such approval from either a county or regional solid waste authority, or from a county commission, under any prior enactment of this code, and facilities which were otherwise exempted from local site approval under any prior enactment of this code, shall be deemed to have satisfied such requirement. All other facilities, including facilities which received such local approval but which seek to expand spatial area or to convert from a Class B facility to a Class A facility, shall obtain such approval only in the manner specified in sections twenty-six, twenty-seven and twenty-eight of this article.

(b) In considering whether to issue or deny the certificate of site approval as specified in sections twenty-six, twenty-seven and twenty-eight of this article, the county or regional solid waste authority shall base its determination upon the following criteria: The efficient disposal of solid waste anticipated to be received or processed at the facility, including solid waste generated within the county or region, economic development, transportation infrastructure, property values, groundwater and surface waters, geological and hydrological conditions, aesthetic and environmental quality, historic or cultural resources, the present or potential land uses for residential, commercial, recreational, industrial or environmental conservation purposes and the public health, welfare and convenience.

(c) The county or regional solid waste authority shall complete findings of fact and conclusions relating to the criteria authorized in subsection (b) of this section which support its decision to issue or deny a certificate of site approval.

(d) The siting approval requirements for composting facilities, materials recovery facilities and mixed waste processing facilities shall be the same as those for other solid waste facilities.