(1) No person shall cause or authorize particulate matter caused by the combustion of fuel to be discharged from any stack or chimney into the outdoor atmosphere in excess of the rates in the following table:

 

                                                                                  Maximum Allowable Emissions of

                                                                                           Particulate Matter in lbs. per

                                                                                           Million British Thermal Units

Heat Input in Million                                   Existing                                              New

British Thermal Units                                 Fuel Burning                          Fuel Burning

per Hour                                                    Equipment                                Equipment

              10 and below                             0.60                                               0.60

             100                                              0.40                                               0.35

          1,000                                              0.28                                              0.20

        10,000 and above                             0.19                                               0.12

 

(2) When the heat input falls between any two consecutive heat input values in the preceding table, maximum allowable emissions of particulate matter for existing fuel burning equipment and new fuel burning equipment must be calculated using the following equations:

 

For existing fuel burning equipment: E = 0.882 * H^-0.1664

For new fuel burning equipment: E = 1.026 * H^-0.233

 

Where H is the heat input capacity in MMBtu per hour and E is the maximum allowable particulate emissions rate in lbs. per MMBtu.

 

For the purposes of this rule, heat input will be calculated as the aggregate heat content of all fuels (using the upper limit of their range of heating value) whose products of combustion pass through the stack or chimney.

(3) When two or more fuel burning units are connected to a single stack, the combined heat input of all units connected to the stack shall not exceed that allowable for the same unit connected to a single stack.

(4) This rule does not apply to emissions from residential solid fuel combustion devices such as fireplaces and wood and coal stoves.

(5) This rule does not apply to particulate matter emitted from:

(a) those new stationary sources listed in ARM 17.8.340 for which a particulate emission standard has been promulgated; and

(b) sources constructed after March 16, 1979, that have a specific particulate emission limitation contained in a Montana air quality permit obtained under ARM Title 17, chapter 8, subchapter 7, a court order, board order or department order, or a process-specific rule.