74 : 36 : 21 : 13 . Calculate a 30-day rolling average. The following procedures shall be used to calculate a 30-day rolling average:

1. (1) Sum the total pounds of pollutant in question emitted from a unit during an operating day and the previous 29 operating days;
2. (2) Sum the total heat input to the unit in million Btus during the operating day and the previous 29 operating days;
3. (3) Sum the total hours the unit operated in hours during the day and the previous 29 operating days;
4. (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. (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.

Source: 46 SDR 64, effective November 25, 2019 .

General Authority: SDCL 34A-1-6.

Law Implemented: SDCL 34A-1-6 .