Mass. Gen. Laws ch. 83 § 24
The owner of any land benefited by the laying out of a particular sewer from the common sewer to the boundary of the way shall pay to the town for the permanent privilege of using the same such reasonable amount as the aldermen or the sewer commissioners, selectmen or road commissioners determine, which may be fixed at the estimated average cost of all such particular sewers within the territory for which a system of sewers has been built or adopted. The board or officers authorized to lay out sewers shall assess the cost of connecting private land with a common sewer under section three upon the land so connected, and may require that an applicant for a connection of his land with a sewer shall pay in advance an amount equal to the estimated assessment therefor, which shall be applied to the payment of the assessment, and the remainder, if any, shall be repaid to the applicant.
Mass. Gen. Laws ch. 83, § 24