Section 1B. At the commencement of operation of the municipalities' sewer system authorized by section 1A, the owner of land abutting upon a private or public way in which a common sewer has been laid shall be required by the board or officer having charge of the maintenance and repair of sewers to connect such land with a common sewer only if the land in question is within the areas identified in the department of environmental protection-approved CWMP and has been specifically identified in the plan as requiring wastewater collection and treatment for flows in existence on said properties at the time of adoption of this act in order to protect surface waters or drinking water resources from the effects of nutrient enrichment; or the on-site subsurface sewage disposal system serving said land fails to comply with the provisions of 310 CMR 15.000, et seq. and an on-site subsurface sewage disposal system cannot be constructed on the property in compliance with said regulations and an enhanced treatment system under remedial use cannot be designed and constructed to adequately treat sewage from said property; or to service housing of which at least 15 per cent of the housing units are deed restricted to residents with incomes no greater than 80 per cent of the area median income paying no more than 30 per cent of their income towards housing. The town shall not allow an abutting property owner utilizing an enhanced treatment system under remedial use to opt out of connecting to the sewer system unless the town implements a monitoring and inspection plan approved by the department of environmental protection for such remedial system or systems. Such plan may include the assessment of a reasonable fee by the board of health to implement the monitoring and inspection plan.

Notwithstanding any provision of sections 1 and 3 to the contrary, owners of land not identified in the CWMP as needing to be connected to the municipal treatment works shall not be permitted to connect to the sewer system. Said plan may be amended from time to time by the board or officer having charge of sewers, after a public hearing conducted to consider such amendment, and upon approval of the department of environmental protection. The board or officer having charge of sewers shall adopt regulations within 120 days after the adoption of this act establishing publication and notification procedures to carry out the purposes of this section.