As used in this article, the term:

1. “Sewage-works corporation” means a corporation heretofore or hereafter organized to provide a sewer system as hereinafter defined for the disposal of sewage, through an established system of pipe lines, treatment plants and other means of disposal, and which erects, operates, maintains and performs other necessary acts incidental thereto, disposal systems for sewer areas formed within towns or villages and other municipal areas of the state.

2. “Sewer system” means all sewer pipes and other appurtenances which are used or useful in whole or in part in connection with the collection, treatment or disposal of sewage, and other waste, including sewage pumping stations and sewage treatment and disposal plants and sites.

3. “Local governing body” means the legislative body of a city, town or village authorized by law to establish a sewer district or otherwise to provide sewage-works facilities in such city, town or village wherein is located the area to be served by the sewage-works corporation.

4. “Sewer district” means a county sewer district established pursuant to article five-A of the county law or a town sewer district established pursuant to article twelve or article twelve-A of the town law.