The Governor, upon the application of any town, city or borough or of any subdivision thereof, or of any company, owning or controlling any system of waterworks or water supply, may commission, during his pleasure, one or more persons, who, having been sworn, may act as policemen for the purpose of preventing and abating nuisances and protecting such water supply from contamination. Such policemen shall arrest, without previous complaint and warrant, any person for an offense under the provisions of any law for the protection of water supplies, when the offender is taken or apprehended in the act or on speedy information of others; and all persons so arrested shall be immediately presented before competent authority. Each such policeman shall, when on duty, wear in plain view a shield bearing the words “Special Police” and the name of the town, city, borough or company for which he is commissioned.