(a) Each gaseous chlorine disinfection and sulfur dioxide dechlorination system must include the number of cylinders required for normal operation at peak flow, plus at least one additional cylinder.(b) Gaseous chlorine disinfection systems and sulfur dioxide dechlorination systems must include a device that automatically switches between cylinders in a manner that ensures continuous disinfection and dechlorination.(c) A wastewater treatment facility must have sufficient space to store at least as many empty cylinders as the number of cylinders required for normal operation at peak flow.(d) A gaseous chemical delivery system must meet the pounds per day requirements in §217.272 of this title (relating to Capacity and Sizing of Gaseous Chlorine Disinfection and Sulfur Dioxide Dechlorination) when the largest chlorinator, sulfonator, or evaporator is out of service.(e) If an injector water supply requires a booster pump, a duplicate backup pump is required.(f) A gaseous chemical delivery system must include an emergency power source capable of operating the chlorination and dechlorination systems during an extended power outage, in accordance with §217.36 of this title (relating to Emergency Power Requirements).