Haw. Rev. Stat. § 54-56: Purchases and contracts.

The board of water supply may contract for work, supplies, materials, or equipment when the cost of these can be met from the revenues or reserves of the waterworks or water systems, or from the proceeds of bonds authorized for the waterworks and water systems. All contracts shall be executed in the name of the board and shall be signed by the chairperson or acting chairperson of the board.

The board may sell or otherwise dispose of any buildings, materials, supplies, or equipment under its control when no longer used or useful for its purposes, and the proceeds thereof shall be placed to the credit of the board. All documents of transfer shall be executed in the name of the board and shall be signed by the chairperson or acting chairperson thereof.