(1) Unless required to obtain an open burning permit under another provision of this subchapter, a minor open burning source need not obtain an air quality open burning permit.

(2) A minor open burning source must:

(a) conform with BACT;

(b) comply with all rules in this subchapter, except ARM 17.8.610; and

(c) comply with any requirements or regulations relating to open burning established by any agency of local government, including local air pollution agencies established under 75-2-301 , MCA, of the Montana Clean Air Act, or any other municipal or county agency responsible for protecting public health and welfare.

(3) During September, October, or November, to conduct any minor open burning not prohibited by ARM 17.8.604, a minor open burning source must adhere to the burning restrictions established by the department that are available by calling the department at (800) 225-6779.

(4) During December, January, or February, to conduct any minor open burning that is not prohibited by ARM 17.8.604, a minor open burning source must comply with the following conditions:

(a) Outside the eastern Montana open burning zone, a minor open burning source must:

(i) submit a written request to the department, demonstrating that the essential agricultural open burning or prescribed wildland open burning, or any minor open burning that is not prohibited by ARM 17.8.604 must be conducted prior to reopening of open burning in March;

(ii) receive permission for each specific burn from the department; and

(iii) adhere to the time periods set for burning by the department that are available by calling the department at (800) 225-6779.

(b) Inside the eastern Montana open burning zone, a minor open burning source need only notify the department by telephone of any essential agricultural open burning, prescribed wildland open burning, or any other minor open burning that is not prohibited by ARM 17.8.604 prior to ignition. Burning is allowed when ventilation conditions are good or excellent. Ventilation conditions are determined by the department using a ventilation index, which is defined as the product of the mixing depth in feet at the time of the daily maximum temperature, times the average transport wind in knots through the mixed layer divided by 100. Good or excellent ventilation conditions exist when the ventilation index is 400 or higher. Forecasts of ventilation conditions may be obtained by calling the department at (800) 225-6779.

(5) During March through August, subject to (2), a minor open burning source may conduct open burning not prohibited under ARM 17.8.604.

(6) The requirements of this rule are in addition to any other applicable state, federal or local open burning requirements.