(a) This section describes the information and procedures you must use to determine the quantity of leather processed at your affected source.

(1) To determine the surface area (i.e., quantity) of leather substrate processed each month at your source for each product process operation, follow the procedures in your plan for demonstrating compliance. You must consistently measure the surface area of processed leather substrate at one of the manufacturing locations listed in paragraph (a)(1)(i) or (ii) of this section:

(i) Measure the surface area of processed leather upon exiting the leather finishing operation.

(ii) Measure the surface area of processed leather upon shipment from the source.

(2) By the fifteenth of each month, you must determine the quantity of leather processed in 1,000's of square feet for each product process operation during the previous month. After collecting data on the amount of leather processed for 12 months, you must also determine by the fifteenth of each month the annual total of leather processed in 1,000's of square feet for each product process operation by summing the monthly quantities of leather processed in each product process operation for the previous 12 months. The “annual total of leather processed” in each product process operation is used in Equation 1 of §63.5340 to calculate your allowable HAP loss as described in §63.5340. Your allowable HAP loss is then subsequently used to calculate your compliance ratio as described in §63.5330.

(b) To determine the surface area of leather processed at your source for each product process operation, you must use one of the methods listed in paragraphs (b)(1) and (2) of this section:

(1) Premeasured leather substrate sections being supplied by another manufacturer as an input to your finishing process.

(2) Measure the surface area of each piece of processed or shipped leather with a computer scanning system accurate to 0.1 square feet. The computer scanning system must be initially calibrated for minimum accuracy to the manufacturer's specifications. For similar leather production runs, use an average based on a minimum of 500 pieces of leather in lieu of individual measurements.

(c) Except as provided in paragraph (d) of this section, you must include the surface area of each piece of processed leather only once when determining the monthly quantity of leather processed, regardless of the number of times a piece of leather is reprocessed through a portion of the finishing operations.

(d) If a piece of leather is completely stripped of all applied finishes and reprocessed through the entire finishing operation as if it were a new piece of leather, you may recount the surface area of leather reprocessed when determining the monthly quantity of leather processed.