(a) Collection methods.--If an assessment remains unpaid at the expiration of the 30-day personal notice and an installment agreement has not been entered into pursuant to section 21A06 (relating to petition for viewers), the borough solicitor shall collect the unpaid assessment, with interest from the time of completion of the improvement or from the time of filing a certificate of assessment with council, plus costs, by filing a lien to be collected in the same manner as municipal claims or by action in assumpsit. When a property owner has two or more lots against which there is an assessment for the same improvement, all of the lots may be embraced in one claim.

(b) Payment location.--Assessments, whether paid one time or by installments, shall be payable at the office of the borough treasurer or any other place as the applicable ordinance shall provide.