ARSD 74:36:21:13. Calculate a 30-day rolling average

The following procedures shall be used to calculate a 30-day rolling average: (1) Sum the total pounds of pollutant in question emitted from a unit during an operating day and the previous 29 operating days; (2) Sum the total heat input to the unit in million Btus during the operating day and the previous 29 operating days; (3) Sum the total hours the unit operated in hours during the day and the previous 29 operating days; (4) For pounds per million Btus, divide the total number of pounds of the pollutant emitted during the 30-day operating days by the total heat input during the 30-day operating days; (5) For pounds per hour, divide the total number of pounds of the pollutant emitted during the 30-day operating days by the total hours operated during the 30-day operating days. A new 30-day rolling average shall be calculated for each new operating day. Each 30-day rolling average shall represent all emissions, including emissions that occur during periods of startup, shut down, and malfunction.