Is underground storage included in the definition of a process?

Would underground storage of a regulated substance listed at 40 CFR §68.130 subject a stationary source owner or operator to the risk management program regulations?

If more than a threshold quantity of a regulated substance is present in a process at a stationary source, the owner or operator of that source must comply with the risk management program regulations at 40 CFR Part 68. The definition of "process" includes storage of a regulated substance, and there is no general exemption for underground storage.