Section 13-684. Reimbursement by authority responsible for supplementation

a.  The cost of providing a supplemental retirement  allowance  pursuant
  to  section  13-680  of this chapter to each qualified authority retiree
  shall be paid to the city, in the manner provided for by  this  section,
  by  the  authority  responsible for supplementation with respect to such
  retiree.
    b. As  soon  as  practicable  after  December  thirty-first,  nineteen
  hundred  seventy-one,  the  comptroller  shall  determine  the  pro-rata
  portion of the cost of providing supplemental retirement  allowances  to
  qualified  authority retirees, pursuant to sections 13-680 and 13-682 of
  this chapter, which is required to be paid by each authority responsible
  for supplementation. Such pro-rata cost shall be determined on the basis
  of a formula approved by the board of estimate.
    c. The comptroller shall thereupon submit to  the  fiscal  officer  of
  each  such  authority  a statement of the amount which such authority is
  required to pay to the city pursuant to this  article.  Payment  of  the
  amount  specified  in  the comptroller's statement shall be made by such
  authority within sixty days after the receipt thereof. If payment of the
  full amount of such obligation is not made within sixty days  after  the
  receipt  of  such  statement, interest at the rate of four percentum per
  annum shall commence to run against the unpaid balance  thereof  on  the
  first day after such sixtieth day.
    d.  All  amounts  received  by  the  comptroller from such authorities
  pursuant to this article shall be  deposited  in  and  credited  to  the
  supplemental pension fund.
    e.  The  provisions  of  this  section  shall  apply  to  supplemental
  retirement allowances payable pursuant to the provisions of this article
  for periods prior to July first, nineteen hundred eighty and  shall  not
  apply  to  any  such  supplemental retirement allowances payable for any
  period thereafter.