53 Pa. Stat. § 2831
Whenever the consent of the Commonwealth of Pennsylvania has been or shall be granted to any city to construct and maintain a dam, in a public navigable river or stream flowing through, or partly within and partly without its corporate limits, for the purpose of improving the sanitary conditions of such city, power is hereby conferred upon it to purchase, acquire, enter upon, take, use and appropriate private property, either within or without its territorial limits, for that purpose; and if said city cannot agree with the owner or owners, lessee or lessees, of such private property upon the compensation for the property appropriated or the damages done, or when by reason of the absence or legal incapacity of any such owner or owners, lessee or lessees, no such compensation can be agreed upon, the court of common pleas of the county in which such property may be situate, or any judge thereof in vacation, on application thereto by petition by said city or such owner, lessee, or any person interested, shall appoint viewers, in accordance with the existing law or laws governing the taking of private property under the power of eminent domain, to view and ascertain the damages done by reason of such taking, use, appropriation, occupancy, or injury. All proceedings to be had and report made, with the right of appeal and exception, in accordance with the existing law or laws aforesaid, in such case made and provided.
53 P.S. § 2831