Notwithstanding any provision of this chapter and subsection (f) of § 5-278 to the contrary, any member of the state employees retirement system (1) who is in active state service or receiving workers’ compensation payments, and who has ten or more years of credited state service and is eligible to retire on or before July 1, 1989, or (2) who is eligible for a disability retirement pursuant to § 5-169 or 5-192p on or before July 1, 1989, shall be eligible for a supplemental retirement benefit, provided such member submits a written application for retirement to the Retirement Division of the office of the Comptroller on or after June 1, 1989, but before October 1, 1989. Such retirement shall become effective the first day of the month following receipt of such application. No member whose application for retirement is received on or after October 1, 1989, shall be eligible for such benefit. The amount of the supplemental retirement benefit shall be equal to two per cent of such member’s annual base rate of pay, in accordance with any applicable compensation schedule, as of June 29, 1989, multiplied by the number of such member’s completed years of credited state service, taken to completed months, provided accrued vacation time shall not be considered credited state service for the purposes of such benefit, and provided further the amount of any such benefit shall not exceed twenty-one thousand six hundred dollars. The supplemental retirement benefit shall be paid to such member in thirty-six equal monthly installments, commencing with the month in which such member’s retirement becomes effective. If any such member dies before such payments are completed the remainder of the benefit payable to such member pursuant to this section shall be paid to such member’s estate in a single payment.