9. a. The council may authorize a municipality that has petitioned for substantive certification to impose and collect payments-in-lieu of constructing affordable units on site upon the construction of residential development, which payments may be imposed and collected as provided pursuant to the rules of the council. Payment-in-lieu fees shall be deposited into a trust fund, and accounted for separately from any other fees collected by a municipality. Whenever a payment-in-lieu is charged by a municipality pursuant to this subsection, a development fee authorized pursuant to section 8 of P.L.2008, c.46 (C. 52:27D-329.2) shall not be charged in connection with the same development.

b. A municipality shall commit to expend collections from payments-in-lieu imposed pursuant to subsection a. of this section within four years of the date of collection. The council may extend this deadline if the municipality submits sufficient proof of building or other permits, or other efforts concerning land acquisition or project development. The council shall provide such administrative assistance as may be required to aid in the construction of affordable housing units. A municipality that fails to commit to expend the amounts collected pursuant to this section within the timeframes established shall be required to transfer any unexpended revenue collected pursuant to subsection a. of this section to the “New Jersey Affordable Housing Trust Fund,” established pursuant to section 20 of P.L.1985, c.222 (C. 52:27D-320), to be used within the same housing region for the authorized purposes of that fund, in accordance with regulations promulgated by the council.

L.2008, c.46, s.9.