Advances under this subchapter shall be repaid when construction of the facilities or any portion thereof is undertaken. Where a construction grant or loan is authorized by the Department for the project, the amount of the outstanding advances shall be retained from the initial payments of the grant or loan funds. In other instances, if repayment is not made within 60 days upon demand by the Department, the sum shall bear interest at the rate of 12 percent per annum from the date payment is demanded by the Department to the date of payment by the municipality. The Department may approve proportional repayment when construction is initiated on a small portion of the planned project. (Added 2015, No. 103 (Adj. Sess.), § 37, eff. May 12, 2016.)