53 Pa. Stat. § 2201
All cities of the commonwealth are hereby authorized and empowered, by themselves, their agents, artisans, engineers, and workmen, with their tools, appliances, instruments, carts, wagons, and other carriages, and beasts of burden or draft, from time to time and at all time hereafter, for the purpose of establishing and constructing a system of sewers and drains, to enter into such lands and enclosures, and public or private roads or highways, or over or through any private streams, as may be necessary, and to occupy, excavate and lay sewers and drains through the same, to maintain, alter and repair, doing as little damage to private property as possible, and making compensation to the owner or owners thereof in the manner hereinafter provided.
53 P.S. § 2201