Mass. Gen. Laws ch. 165, § 11D

Any person employed by a city, town, district or company engaged in supplying water who displays on his outer garment a suitable identification badge bearing his photograph, issued to him by his employer, may at any reasonable time enter any premises supplied with water by such city, town, district or company for the purpose of examining or removing meters, pipes, fittings and works for supplying or regulating the supply of water and of ascertaining the quantity of water consumed or supplied.