Section 4A. The chief executive officer of a city or town, or a board, committee or officer authorized by law to execute a contract in the name of a governmental unit may, on behalf of the unit, enter into an agreement with another governmental unit to perform jointly or for that unit's services, activities or undertakings which any of the contracting units is authorized by law to perform, if the agreement is authorized by the parties thereto, in a city by the city council with the approval of the mayor, in a town by the board of selectmen and in a district by the prudential committee; provided, however, that when the agreement involves the expenditure of funds for establishing supplementary education centers and innovative educational programs, the agreement and its termination shall be authorized by the school committee. Any such agreement shall be for such maximum term, not exceeding twenty-five years, and shall establish such maximum financial liability of the parties, as may be specified in the authorizing votes of the parties thereto. A governmental unit, when duly authorized to do so in accordance with the provisions of law applicable to it, may raise money by any lawful means, including the incurring of debt for purposes for which it may legally incur debt, to meet its obligations under such agreement. Notwithstanding any provisions of law or charter to the contrary, no governmental unit shall be exempt from liability for its obligations under an agreement lawfully entered into in accordance with this section. For the purposes of this section, a ''governmental unit'' shall mean a city, town or a regional school district, a district as defined in section 1A, a regional planning commission, however constituted, a regional transit authority established under chapter 161B, a water and sewer commission established under chapter 40N or by special law, a county, or a state agency as defined in section 1 of chapter 6A.

All agreements put into effect under this section shall provide sufficient financial safeguards for all participants, including, but not limited to: accurate and comprehensive records of services performed, costs incurred, and reimbursements and contributions received; the performance of regular audits of such records; and provisions for officers responsible for the agreement to give appropriate performance bonds. The agreement shall also require that periodic financial statements be issued to all participants. Nothing in this section shall prohibit any agreement entered into between governmental units from containing procedures for withdrawal of a governmental unit from said agreement. A decision to enter into an intermunicipal agreement under this section, or to join a regional entity, shall be solely subject to the approval process of the towns' elected bodies.

All bills and payrolls submitted for work done under any such agreement shall be plainly marked to indicate that the work was done under authority thereof. Any reimbursement for or contribution toward the cost of such work shall be made at such intervals as the agreement provides. The amount of reimbursement received under any such agreement by any governmental unit shall be credited on its books to the account of estimated receipts, but any funds received under the provisions of section fifty-three A of chapter forty-four for contribution toward the cost of such work may be expended in accordance with the said provisions. The equipment and employees of a governmental unit while engaged in performing any such service, activity or undertaking under such an agreement shall be deemed to be engaged in the service and employment of such unit, notwithstanding such service, activity or undertaking is being performed in or for another governmental unit or units.