Do the risk management program regulations at 40 CFR Part 68 place additional requirements on stationary sources that are currently in compliance with all other provisions of the Clean Air Act (CAA)?

Yes.  Owners and operators of stationary sources who meet the applicability criteria at 40 CFR §68.10 must comply with the risk management program regulations of 40 CFR Part 68, in addition to other CAA requirements.  If a source is subject to both 40 CFR Part 68 and Part 70 or 71, the Part 70 or 71 permit for the stationary source must provide assurance of compliance with §112(r) (40 CFR §68.215).