(a) The term "undertaking" shall include the following revenue-producing undertakings, whether now existing or hereafter acquired or constructed: Causeways, tunnels, viaducts, bridges and other crossings; highways, parkways, airports, docks, piers and wharves; systems, plants, works, instrumentalities and properties used or useful in connection with (i) the obtaining of a water supply and the collection, treatment and disposal of water for public and private uses, (ii) the collection, treatment and disposal of sewage, waste and storm water, and (iii) resource recovery from municipal solid waste through the use of structures, machinery or devices involving the separation, extraction and recovery of useable materials, energy or heat; together with all parts of any such undertaking and all appurtenances thereto including lands, easements, rights of way, contract rights, franchises, approaches, connections, dams, reservoirs, sewage disposal plants, intercepting sewers, trunk, connecting and other sewer and water mains, filtration works, pumping stations and equipment.

(b) The term "municipality" shall mean a county, town, city or village.

(c) The term "governing body" shall mean the board of supervisors of a county, the town board of a town, the board of estimate and apportionment or other board performing similar functions in any city now or hereafter having a population of more than eight hundred thousand, except that in the city of New York the term governing body shall mean the officer or agency vested with power under the charter of such city or by other law, to act pursuant to this chapter; the city council, the common council, the municipal assembly or other legislative body of any other city, and the board of trustees of a village.