53 Pa. Stat. § 1231
Hereafter the exclusive methods for the collection of benefits assessed against any property in any proceedings by the appointment of viewers for the assessment of benefits incident to any public improvement in any city, borough, or township, shall be either by an action of assumpsit against the owner of the property, or by the filing and collection of a municipal lien in the manner now provided by law.
In all cases where benefits in any such proceedings have been or shall be assessed against any property, it shall be the duty of the municipal authorities, within six months after the absolute confirmation of the report of viewers, to forthwith file the necessary municipal lien or liens to protect the interests of the city, borough, or township, and recovery may be had thereon in the manner now provided for the recovery of municipal liens.
This act shall apply to all proceedings now pending in any city, borough, or township, as well as to all proceedings hereafter instituted.
53 P.S. § 1231