Section 22. Interpretation of emission standards based on process weight rate tables

A. General. Unless otherwise approved by the board, interpretation of emission standards based on process weight rate tables shall be in accordance with this section.

B. Definitions.

1. For the purpose of these regulations and subsequent amendments of any orders issued by the board, the words or terms shall have the meaning given them in subdivision B 3 of this section.

2. As used in this section, all terms not defined here shall have the meaning given them in 9VAC5 Chapter 10 (9VAC5-10-10 et seq.), unless otherwise required by context.

3. Terms defined.

"Manufacturing operation" means any process operation or combination of physically connected dissimilar process operations which is operated to effect physical or chemical changes, or both, in an article.

"Materials handling equipment" means any equipment used as a part of a process operation or combination of process operations which does not effect a physical or chemical change in the material or in an article, such as, but not limited to, conveyors, elevators, feeders or weighers.

"Physically connected" means any combination of process operations connected by materials handling equipment and designed for simultaneous complementary operation.

"Process operations" means any method, from, action, operation or treatment of manufacturing or processing, including any storage or handling of materials or products before, during or after manufacturing or processing.

"Process unit" means any step in a manufacturing or process operation which results in the emission of pollutants to the atmosphere.

"Process weight" means total weight of all materials introduced into any process unit which may cause any emission of pollutants. Process weight includes solid fuels charged, but does not include liquid and gaseous fuels charged or combustion air for all fuels.

"Process weight rate" means a rate established as follows:

(1) For continuous or long-run steady-state process operations, the total process weight for the entire period of continuous operation or for a typical portion of it, divided by the number of hours of such period or portion of it.

(2) For cyclical or batch process operations, the total weight for a period that covers a complete operation or an integral number of cycles, divided by the hours of actual process operation during such a period.

"Production rate" means the weight of final product obtained per hour of operation. If the rate of product going to storage can vary, the production rate shall be determined by calculation from the feed rates of raw material.

C. Interpretation of standards.

1. The total process weight rate for each individual process unit at a plant or premises shall be used for determining the maximum allowable emission rate of particulate that passes through a stack or stacks.

2. Unless otherwise specified, the allowable particulate mass emission rate shall be determined for individual units of equipment.

3. Unless otherwise specified or unless an equation is provided, the particulate emission limit above the maximum process weight rate shall be determined by linear interpolation. For interpolation between two values on a process weight rate table the following equation should be used:

	E = [EG - EL]	P - PL	+ EL
		PG - PL

where: E = emission rate being calculated.

E_L = emission rate for P_L as determined from the process weight rate table.

E_G = emission rate for P_G as determined from the process weight rate table.

P = process weight rate of the unit.

P_L = process weight rate in the process weight rate table which is closest to but less than the process weight rate of the unit.

P_G = process weight rate listed in the process weight rate table which is closest to but greater than the process weight rate of the unit.

4. Where the nature of any process or design of any equipment is such as to permit more than one interpretation of a regulation, the interpretation that results in the minimum value for allowable emissions shall apply.

5. The following are examples that illustrate how the requirements apply to similar units manifolded to a common stack and a number of process units that are combined in a row. (For the purposes of this illustration an emission rate of 0.551 pounds per hour for a process weight rate of 100 pounds per hour was used.)

Historical Notes

Derived from Volume 13, Issue 18, eff. July 1, 1997.

Statutory Authority

§ 10.1-1308 of the Code of Virginia.