Section 1D. Notwithstanding the provisions of chapters 80 and 83 to the contrary, a municipality acting under section 1A may make assessments upon owners of land abutting upon a private or public way in which a common sewer has been laid only at the time of actual connection to the common sewer. Nothing herein shall preclude the town from making estimated sewer assessments pursuant to section 15B. The municipality may make equitable adjustments to the annual charges established pursuant to section 16 for the use of common sewers by owners of land who connect under this act for the purpose of insuring an equitable distribution of the total sewer system costs, including assessments and sewer use charges.