; (ii) an explosion; (iii) 1 or more fatalities; or (iv) the unscheduled shutdown of gas service to a significant number of customers, as determined by the Secretary; and (B) that provides information regarding— (i) the emergency described in subparagraph (A); and (ii) the status of public safety; and (3) the development and implementation of a voluntary, opt-in system that would allow operators of distribution systems to rapidly communicate with customers in the event of an emergency. . 204. Operations and maintenance manuals Section 60102 of title 49, United States Code (as amended by section 203), is amended by adding at the end the following: (r) Operations and maintenance manuals Not later than 2 years after the date of enactment of this subsection, the Secretary shall update regulations to ensure that each procedural manual for operations, maintenance, and emergencies developed by an operator of a distribution pipeline under section 192.605 of title 49, Code of Federal Regulations (or a successor regulation), includes written procedures for— (1) responding to overpressurization indications, including specific actions and an order of operations for immediately reducing pressure in or shutting down portions of the gas distribution system, if necessary; and (2) a detailed procedure for the management of the change process, which shall— (A) be applied to significant technology, equipment, procedural, and organizational changes to the distribution system