The words "joint meeting" as used in this article shall mean the meeting or assembly of the members of the governing bodies or boards of the several municipalities having authority to make and enter into contracts for the construction jointly of the works or improvements, authorized by section 40:63-70 of this title.
"Improvements or works" when used in this article mean and include all joint outlet and trunk sewers, and sewers or systems of sewers and drains, and joint sewage disposal plants or works and pumping and storage works, and places for the treatment of sewage from such jointly contracting municipalities.
N.J.S. § 40:63-69