If an owner of a stationary source leases propane tanks from a gas supplier, who is responsible for preparing and submitting the risk management plan (RMP) addressing the propane tanks?

The owner of the stationary source is responsible for preparing and submitting the RMP. The risk management program regulations apply to the owner or operator of a stationary source that has more than a threshold quantity of a regulated substance in a process (40 CFR 68.10(a)). Regardless of who owns a particular process (in this case, the propane tanks), the owner or operator of the stationary source at which the process is located is responsible for complying with the risk management program regulations (including submission of the RMP) for the process if it contains more than a threshold quantity of a regulated substance.