N.Y. Village Law § 14-1414
The board of sewer commissioners of a village authorized to construct the whole or any part of a sewerage system shall provide for the construction thereof, either under an entire contract, or in parts or sections, as the board may determine. All contracts shall be let to the lowest responsible bidder after advertisement for bids where so required by section one hundred three of the general municipal law. No contract shall be made by which a greater amount shall be agreed to be paid than the maximum stated in the resolution or in the petition for the construction of such sewerage system. Nothing herein contained shall make it unlawful for the village authorities to make extensions to sewerage systems or to construct additional sewerage systems through or by the officers or employees of a village and authority is hereby granted to all villages to extend sewerage systems and to construct new sewerage systems by village employees under the direction of the superintendent of public works, street commissioner or similar officer, when authorized by resolution of the board of trustees and when in accordance with plans approved by the state department of health.
N.Y. Village Law § 14-1414