Hmm, I thought it was just an IAP (Individual Account Program) which generated "along with the market" returns. But https://www.oregon.gov/pers/mem/pages/section/general_information/opsrp_overview.aspx suggests half the money put into the retirement system goes to an IAP, and half towards a pension that is:
1.5% x years of employment x average salary final 3 years,
So Helfrich could also get .015x8x$2M, maybe = $240,000 a year.

That would be an example of a non-sustainable system. Helfrich got a 10-fold pay raise for his last years compared to being OC, but his pension calculation is just on the final salary while crediting all his years worked. He hasn't put enough into the system to generate a pension of that magnitude. It might work out for an employee that got gradual raises over thirty years of work... the web site says it is designed to pay 45% of final salary for a 30-year worker (1.5% x 30 years).