Multiple Releases During 24-Hour Period
CERCLA release notification requirements state that any person in charge of a vessel or an offshore or an onshore facility shall, as soon as he has knowledge of the release of a hazardous substance in a quantity equal to or exceeding the reportable quantity (RQ), immediately notify the National Response Center (NRC) of such release (40 CFR §302.6(a)). Similarly, EPCRA release notification requirements state that the owner or operator of a facility must provide immediate notification of the release of a reportable quantity of a CERCLA hazardous substance or an EPCRA extremely hazardous substance (EHS) to the Local Emergency Planning Committee (LEPC) and to the State Emergency Response Commission (SERC) (Part 355, Subpart C). If a facility has multiple releases of the same hazardous substance within a 24-hour period, but only one discrete release exceeds the reportable quantity, should the facility report only the quantity released in the discrete event or the total quantity released from all events in the same 24-hour period?
For both CERCLA and EPCRA regulations, a facility must provide immediately notification of the release of a quantity equal to or exceeding the RQ. If the first discrete event in a 24-hour period equals or exceeds the RQ, then facility must provide immediate notification and report the amount released in that event. The facility would not need to provide a second notification if there was another release in the same 24-hour period.
If the first discrete event in a 24-hour period does not equal or exceed the RQ, but a subsequent release in the same 24-hour period causes the facility to equal or exceed the RQ, then the facility should immediately provide notification and report the combined quantity released into the environment.