Pursuant to 40 CFR §68.42(a), the owner or operator of a stationary source subject to the risk management program regulations must document significant accidental releases of regulated substances from a covered process in the five years prior to the submission of an initial or updated risk management plan (RMP). For the five-year accident history, does the owner or operator need to include accidental releases that were only released onto the land or into water?

EPA specifically defines accidental release as an unanticipated emission of a regulated substance or other extremely hazardous substance into the ambient air from a stationary source (§68.3). Therefore, if a regulated substance was released in solid or liquid form to water or land only and  the release did not result in a gas release, liquid spill/evaporation, fire, explosion, or uncontrolled/runaway reaction that generated excessive heat, pressure, or harmful reaction products emitted into the ambient air, it would not be considered an accidental release and the owner or operator would not need to include it in the five year-accident history. However, one of the criteria that EPA used to establish the list of regulated substances for the risk management program was the likelihood of accidental release to air of the substances, based on the statutory authority for the program in the Clean Air Act. As a result, it is unlikely that a regulated substance covered by the risk management program would only be released to land or water.

Additional information on accident history requirements can be found in Chapter 3 of the General Guidance on Risk Management Programs for Chemical Accident Prevention (40 CFR Part 68) (EPA550-B-04-001), available at the following URL:

https://19january2021snapshot.epa.gov/rmp/guidance-facilities-risk-management-programs-rmp