If a participating public employer makes a lump sum payment from moneys not borrowed by the employer to an account established under ORS § 238.229 in an amount equal to or greater than $10 million, the Public Employees Retirement Board shall allow the participating public employer to choose an amortization period of six years, 10 years, 16 years or 20 years for the use of the lump sum payment to offset contributions to the system that the public employer would otherwise be required to make for the liabilities against which the lump sum payment is applied. [2018 c.105 § 3b; 2019 c.355 20,21]