N.Y. GCT Law § 56-A

§ 56-a. Use by the state, individuals and corporations outside\ncorporate limits. 1. Any city having a population of fifty thousand or\nless may sell to a public or private corporation, or to an individual,\nthe right to make connection with its sewer system for the purpose of\ndischarging sewage therein from outside the city limits, and fix the\nterm, consideration and conditions therefor. The board shall not sell\nnor permit the use of its sewer system under this section if thereby\nsuch sewer system will be rendered inadequate for the city or its\ninhabitants. The term "public corporation" shall mean a public\ncorporation as defined in section three of the general corporation law.\n 2. Any city having a population of fifty thousand or less may contract\nwith the state of New York or with the state authority having control\nand supervision of any state institution, and the state of New York or\nthe state authority having control and supervision of any state\ninstitution may contract with the board of sewer commissioners of any\nsuch city, to provide sewerage and sewage disposal facilities for the\nconveyance, treatment and disposal of the sewage of such state or state\ninstitution either within or without the corporate limit of said city on\nsuch conditions and conveying such powers to the state or such state\nauthority and for such consideration and such period of time as said\nsewer commissioners and the state of New York or such state authority\nmay agree.\n 3. Any city having a population of fifty thousand or less may contract\nwith the United States of America or with the federal agency,\nadministration or authority having control and supervision of any\nfederal institution or installation to provide sewerage and sewage\ndisposal facilities for the conveyance, treatment and disposal of the\nsewage of such federal institution or installation either within or\nwithout the corporate limits of the city on such conditions, for such\nconsideration and for such period of time as said sewer commissioners\nand the United States of America or such federal agency, administration\nor authority may agree.\n