(a) General rule.--A township may construct a sanitary sewer and drain in or under any State or county highway within the township boundaries.
(b) Consent.--
(1) For the construction of a sanitary sewer in or under a county highway, the consent of the county commissioners of the county shall be obtained.
(2) For the construction of a sanitary sewer in or under a State highway, the consent of the Department of Transportation shall be obtained.