35 Pa. Stat. § 691.202
No municipality or person shall discharge or permit the discharge of sewage in any manner, directly or indirectly, into the waters of this Commonwealth unless such discharge is authorized by the rules and regulations of the department or such person or municipality has first obtained a permit from the department. Such permit before being operative shall be recorded in the office of the recorder of deeds for the county wherein the outlet of said sewer system is located and in case the municipality or person fails or neglects to record such permit, the department shall cause a copy thereof to be so recorded, and shall collect the cost of recording from the municipality or person. No such permit shall be construed to permit any act otherwise forbidden by any decree, order, sentence or judgment of any court, or by the ordinances of any municipality, or by the rules and regulations of any water company supplying water to the public, or by laws relative to navigation. For the purposes of this section, a discharge of sewage into the waters of the Commonwealth shall include a discharge of sewage by a person or municipality into a sewer system or other facility owned, operated or maintained by another person or municipality and which then flows into the waters of the Commonwealth. A discharge of sewage without a permit or contrary to the terms and conditions of a permit or contrary to the rules and regulations of the department is hereby declared to be a nuisance.
35 P.S. § 691.202