Mass. Gen. Laws ch. 164 § 58A
A sufficient deposit to secure the payment for gas or electricity for 3 months may be required in advance from any consumer, and if the advance deposit is retained for a longer period than 6 months, the interest rate shall be paid annually to said consumer or credited to his account. The rate of interest shall be revised annually and shall be equal to yields on Treasury securities at constant, fixed maturity 1-year rate as published by the Federal Reserve System and as established 12 months ending December of the prior year. The supply may be shut off from any premises until all arrears for gas or electricity furnished thereon to such consumer shall have been paid. After three months default in the payment of such arrears, all appliances for distribution belonging to the municipality on the premises may be removed and shall not be restored except on payment of all such arrears and the expenses of removal and restoration.
Mass. Gen. Laws ch. 164, § 58A