Section 39G. Whoever wilfully or wantonly corrupts, pollutes or diverts any of the waters taken or held under said sections thirty-nine A to thirty-nine E, inclusive, or injures any structure, work or other property owned, held or used by a town under the authority and for the purposes of said sections, shall forfeit and pay to said town three times the amount of damages assessed therefor, to be recovered in an action of tort; and upon conviction of any one of the above wilful or wanton acts shall be punished by a fine of not more than $5,000 or by imprisonment in state prison for not more than 5 years or in the house of correction for not more than 2 years or by both such fine and imprisonment.