Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 165, § 11A

Except as otherwise provided in this chapter, a water company may shut off the flow of water from its mains or pipes to the premises of any customer who has failed or refused to pay the lawful charges of said company for water previously consumed. The officers, employees or agents of said company may, upon any business day between the hours of eight ante meridian and four post meridian, enter upon the premises of a customer whose payments are in arrears and close a valve, remove or disconnect a meter pipe or fitting, if necessary, for the purpose of shutting off the flow of water as above authorized, provided, however, that the customer has been given thirty-six hours notice in person or by registered or certified mail directed to his last address furnished to the company. If such address is different from the address of the premises affected a copy of such notice shall also be so mailed to the address thereof.