Section 31A. Subject to appropriation, the department of environmental protection shall administer a matching grant program for communities who desire to join the Massachusetts Water Resources Authority or any other regional system for wastewater, drinking water or for both wastewater and drinking water. Each grant shall match, on a 1:1 basis, money committed by a local government unit or a regional local governmental unit, as defined in section 1 of chapter 29C, to pay the entry fee established by the: Massachusetts Water Resources Authority, under section 8 of chapter 372 of the acts of 1984; or other fees required to join a regional system. The department shall award grants only to a local governmental unit or regional local governmental unit that satisfies the department that it has committed funds to join said Authority or regional system. Should the local governmental unit or regional local governmental unit fail to join said Authority or regional system after receiving a grant under this section, the local governmental unit or regional local governmental unit shall return money granted under this section to the department.

For the purpose of this section, the term ''regional system'' shall include any system established by mutual agreement of 2 or more municipalities or by a county in which all municipalities of said county have an agreement to provide drinking water or wastewater services, or both, through shared facilities, sources or distribution networks.