53 Pa. Stat. § 2906
Prior to any appropriation, the city or borough shall attempt to agree with the owner as to the damage done or likely to be done to him. If the parties cannot agree, or the owner cannot be found, or is not sui juris, the said city or borough may file its bonds in the common pleas court of the county, conditioned for the payment, to the owner or owners of the property appropriated, of the damages for the taking thereof, when the same shall have been ascertained according to law. Upon the approval of the bond, and its being filed, the right of the corporation to enter upon the property or rights intended to be appropriated shall be complete. Upon petition of either the property owner or the city, or borough, at any time thereafter, the said court shall appoint three disinterested freeholders of the county to serve as viewers, to assess the damages proper to be paid to the owner for the property or rights appropriated, and shall fix a time for their meeting, of which notice shall be given to both parties. When the report is filed either party may appeal and have a jury trial, as provided by law.
53 P.S. § 2906