(a) Conduct any required compliance demonstration according to the requirements in § 63.5993 (b), (c), and (d).

(b) You must use the methods in table 17 of this subpart and according to paragraphs (b)(1) through (b)(3) of this section to measure emissions and stack gas flow rates and characteristics to determine THC and fPM or metal HAP mass emission rates in grams per day.

(1) You must operate a THC CEMS in accordance with the requirements in § 63.6012 and Performance Specification 8A in appendix B to 40 CFR part 60. For the purposes of conducting the accuracy and quality assurance evaluations for CEMS, the reference method (RM) is Method 25A of appendix A-7 to 40 CFR part 60. Owners or operators are responsible for ensuring their instruments provide appropriate data continuously. If a THC monitor will be used for an emission stream that could have a wide variability in THC concentrations because of mixing both high-emitting and low-emitting compounds at different times, then a dual-span monitor should be considered for use. If the THC monitor is used for emissions that are relatively constant, then a dual-span monitor may not be needed, but it remains the responsibility of source owners or operators to make that determination. Owners and operators cannot discard from the compliance determination THC concentration data that exceed the calibration range of the monitor.

(2) Use the THC CEMS to conduct the initial compliance test for the first 15 mixer operating days after the applicable compliance date for each mixer. All THC values must be used as they are recorded by the THC CEMS, except that negative values equal to or greater than to −5 should be treated as zeros, and values less than (i.e., more negative than) −5 cannot be used as valid compliance data in the calculations.

(3) To convert the THC concentration measurements to mass emission rates, you must measure the volumetric flow rate in the same duct or stack in which the THC concentration is monitored no less frequently than once every 5 years. You may use the same flow rate measurements that are completed for demonstrating compliance with the emission limits for fPM or total metal HAP according to table 17 of this subpart. If you change operations in a way that would likely result in a change to volumetric flow rate, you must conduct an additional measurement of the new volumetric flow rate.

(c) You must monitor mixed rubber compound processed in each mixer in Mg per day during the testing for THC. During the testing for fPM or total metal HAP, you must monitor the mixed rubber compound processed in each mixer in Mg for the same periods that fPM or total metal HAP testing runs are performed, excluding the mass of rubber processed during the time between fPM or metal HAP sampling runs.

(d) You must use the methods in paragraphs (d)(1) and (d)(2) of this section to calculate the THC emission rate for the 15-day initial compliance period to demonstrate initial compliance. You must use the average THC emission rate obtained during the first 15 mixer operating days after the applicable compliance date to determine initial compliance for each mixer, group of mixers routed to the same control device or stack, or all mixers combined if complying with the facility-wide average alternative.

(1) Use Equation 1 to paragraph (d)(1) of this section to calculate the 15-day average THC emission rate in grams THC per megagram of mixed rubber compound processed. This emission rate is calculated for each rubber mixer separately, group of mixers routed to the same control device or stack, or for all rubber mixers combined if complying with the facility-wide average alternative.

(2) Use Equation 2 to paragraph (d)(2) of this section to calculate the THC emission rate in grams per day THC as propane for each day i in the 15-day initial compliance period for rubber processing for each rubber mixer emission stack.

(e) You must use Equation 3 to this paragraph to calculate the fPM emission rate in grams per megagram of mixed rubber compound processed or use Equation 4 to of this paragraph to calculate the metal HAP emission rate in grams per megagram of mixed rubber compound processed to demonstrate initial compliance. The rubber mass processed at each mixer must be recorded for the exact same period of time as the fPM or metal HAP emissions are measured at each mixer. If you are demonstrating compliance with the facility-wide emission average alternative, the relevant measurement of fPM or metal HAP, as appropriate, at each mixer does not need to be done simultaneously for all mixers, but all tests of mixers to be averaged must be done within the same 3-month period.