How is an off-site release subject to EPCRA 304?

How is an off-site release determined to be subject to Section 304 notification requirements?

A release need not result in actual exposure to persons off-site in order to be subject to release reporting requirements; potential exposure is sufficient.  Any release into the environment above the reportable quantity may have the potential to result in exposure to persons off-site and therefore should be reported under Section 304 notification.