53 Pa. Stat. § 2875
All assessments for benefits against private property shall remain a lien thereon from the time the report of viewers is filed in court until paid, unless the liens thereof be lost by failure to revive the same. It shall be the duty of the municipality within six months after its order that the works and improvements have been completed, to file in the office of the prothonotary of the proper county liens for all benefits assessed which remain unpaid. But no such lien shall be filed unless the municipality shall first notify by mail addressed to the last known post office address of the owner or reputed owner of the property against which an assessment has been made, of its intention to have said lien filed if payment of the amount due is not made before a time prescribed by the municipality. Such lien shall be filed in the same manner as is provided by law for the filing of municipal claims and shall have priority over all other liens except taxes and other municipal claims, and except also mortgages and judgments of record prior to the time the report of the viewers was filed in court.
Such liens shall be revived, prosecuted to judgment, executed and collected by the municipality in the same manner in all respects as is provided by law in the case of municipal claims.
53 P.S. § 2875