; (ii) the gas pressure of a low-pressure distribution system is monitored, particularly at or near the location of critical pressure-control equipment; (iii) the regulator station has secondary or backup pressure-relieving or overpressure-protection safety technology, such as a relief valve or automatic shutoff valve, or other pressure-limiting devices appropriate for the configuration and siting of the station and, in the case of a regulator station that employs the primary and monitor regulator design, the operator shall eliminate the common mode of failure or provide backup protection capable of either shutting the flow of gas, relieving gas to the atmosphere to fully protect the distribution system from overpressurization events, or there must be technology in place to eliminate a common mode of failure; and (iv) if the Secretary determines that it is not operationally possible for an operator to implement the requirements under clause (iii), the Secretary shall require such operator to identify actions in their plan that minimize the risk of an overpressurization event. .