N.J. Stat. § 40:62-136
Whenever any work to be performed or materials to be furnished may involve an expenditure of a sum exceeding $2,500.00, the commission shall designate the time when it will meet at its usual place of meeting to receive proposals in writing for doing such work or furnishing such materials, as the case may be, and shall thereupon order that notice shall be given by advertisement in 1 or more newspapers circulating in 1 or more of the municipalities represented by the commission, at least 10 days before the time of the meeting. The advertisement shall specify the dimensions and quality of the work to be done or materials to be furnished. All the proposals shall be publicly opened in the presence of those who choose to attend, and the commission may reject any or all proposals, and advertise for new proposals, and the contract for the work and materials, when awarded, shall be awarded to the lowest responsible bidder.
This section shall not be construed to apply to the compensation of specially retained advisers, and when the exigency of the service of an emergency threatening the continuity of the water supply shall be declared by resolution passed by the unanimous vote of the members of the commission, which resolution shall set forth the nature of the exigency or emergency, and shall state the approximate cost of the work in excess of $2,500.00 necessary to be done to meet the exigency or emergency, the necessity for advertising and receiving proposals provided for in this section shall not apply.
N.J.S. § 40:62-136