For the purposes of this act, an "improvement to real estate" or "improvement" shall mean any structure, machinery, equipment, device or facility necessary to the installation or maintenance of a potable water supply system or a water-carried sewerage disposal system in accordance with the provisions of sections 26, 27 or 28 of chapter 71 of the laws of 1945, as amended and supplemented.
N.J.S. § 54:4-3.60