(a) The owner or operator shall install, calibrate, and maintain a continuous emissions monitoring system (CEMS) to monitor exhaust sulfur dioxide (SO2) from the Boiler Stacks, Boiler 1 and 2 Common Stack (EPN 119) in accordance with the requirements of 40 Code of Federal Regulations (CFR) §60.13, 40 CFR Part 60, Appendix B, Performance Specification 2 and 6, for SO2, and 40 CFR Part 60, Appendix F, quality assurance procedures.
(b) The owner or operator shall monitor the sulfur content of the carbon black oil feedstock and produced carbon black, as well as the production rate of the carbon black, as follows:
  (1) measure twice daily at least four hours apart the sulfur content by weight of the carbon black oil in the feed to each production unit according to the requirements of §112.245 of this title (relating to Approved Test Methods);
  (2) for each grade of carbon black produced, measure daily the sulfur content by weight of the carbon black produced by each carbon black production unit according to the requirements of §112.245 of this title; and
  (3) determine hourly the amount of each grade of carbon black produced by each carbon black production unit.
(c) The owner or operator shall install, calibrate, maintain, and operate one or more totalizing fuel flow meters, with an accuracy of ±5%, to continuously measure the feed rate of carbon black oil feedstock supplied to each carbon black production unit.
(d) The owner or operator shall install, calibrate, maintain, and operate totalizing tail gas flow meters, with an accuracy of ±5%, to continuously measure the volumetric flow rate of tail gas to each tail gas combustion device covered under §112.242 of this title (relating to Control Requirements).
(e) Continuous monitoring data collected in accordance with requirements in this subsection must undergo an appropriate quality assurance and quality control process and be validated for at least 95% of the time that the monitored emission point has emissions; an owner or operator must utilize an appropriate data substitution process based on the most accurate methodology available, which is at least equivalent to engineering judgment, to obtain all missing or invalidated monitoring data for the remaining period the monitored emission point has emissions.
(f) The owner or operator shall calculate hourly SO2 emissions from the Plant 1 Dryer Stack (EPN 121) using the following equation.
Attached Graphic
(g) The owner or operator shall calculate hourly SO2 emissions from the Plant 2 Dryer Stack (EPN 122) using the following equation.
Attached Graphic
(h) The owner or operator shall calculate hourly SO2 emissions from the New Flare (EPN New Flare) or Plant 1, Unit 1 Primary Bag Filter Flare (EPN Flare-1), as applicable using the following equation.
Attached Graphic
(i) Emissions of SO2 from each EPN specified under §112.242 of this title during any block one-hour period must be determined on a block one-hour average.
(j) The owner or operator shall calculate total SO2 emissions generated by each production unit using the following equation.
Attached Graphic
(k) In lieu of the monitoring requirements of §112.243(b) - (d) of this section and §112.243(f) - (j) of this section, the owner or operator may install, operate, calibrate, and maintain a continuous emissions monitoring system to monitor exhaust sulfur dioxide (SO2) from Plant 1 Dryer Stack (EPN 121) or Plant 2 Dryer Stack (EPN 122) in accordance with the requirements of 40 Code of Federal Regulations (CFR) §60.13, 40 CFR Part 60, Appendix B, Performance Specification 2 and 6, for SO2, and 40 CFR Part 60, Appendix F, quality assurance procedures. If a CEMS is not used to monitor the emissions from both EPNs, monitoring requirements in §112.243(b) - (d) of this section and §112.243(f) - (j) of this section continue to apply to EPNs without a CEMS.
(l) Minor modifications to monitoring methods may be approved by the executive director. Monitoring methods other than those specified in this section may be used if approved by the executive director and validated by 40 CFR Part 63, Appendix A, Test Method 301. For the purposes of this subsection, substitute "executive director" in each place that Test Method 301 references "administrator." These validation procedures may be waived by the executive director or a different protocol may be granted for site-specific applications. Minor modifications that may be approved under this subsection include increases in the frequency of monitoring provided appropriate quality assurance control, accuracy specifications, and data validation requirements are specified and no less stringent than monitoring requirements for a comparable EPN in this division.

Source Note: The provisions of this §112.243 adopted to be effective October 27, 2022, 47 TexReg 6985