RSA 147:14: Drainage.

No person shall discharge, leave, or cause to be discharged or left, within the limits of any public highway, any drainage or discharges from any privy, toilet, sink drain, cesspool or septic tank, when such discharges or matter may enter or pass through any open highway ditch or drainage structure constructed and maintained for highway drainage purposes. It shall be the duty of the highway commissioner or selectmen who have control over such highways to report all violations of this section to the local or state health authorities. Any person neglecting or refusing to comply with the provisions of this section shall be guilty of a violation for each day of neglect or refusal, after notice as provided in RSA 147:4.