SECTION 112.233. Monitoring Requirements

(a) Separately for 29 FCCU Stack (EPN 29P1) and 40 FCCU Stack (EPN 40P1), the owner or operator shall install, operate, calibrate, and maintain a continuous emissions monitoring system (CEMS) as specified in 40 Code of Federal Regulations (CFR) §60.105a(g)(1), (2) and (5) regardless of whether these provisions otherwise apply or provide exemptions for certain activities; use an analyzer with a minimum analyzer accuracy of plus or minus (±)2.5%, a dedicated totalizing gas flow measurement system with a minimum measurement accuracy of ±5%, and temperature monitor with a minimum accuracy of ±1%; convert data from all monitoring devices to a common concentration, flow, pressure, and temperature measurement basis and calculate and record 15-minute and subsequent block one-hour average sulfur dioxide (SO₂) emissions.

(b) Separately for SRU Incinerator (EPN 34I1) and SCOT Unit Incinerator (EPN 43I1), the owner or operator shall install, operate, calibrate, and maintain a CEMS as specified in 40 Code of Federal Regulations (CFR) §60.106a(a), regardless of whether these provisions otherwise apply; use an analyzer with an accuracy of plus or minus (±)2.5%, a dedicated totalizing gas flow measurement system with an accuracy of ±5%, and temperature monitor with an accuracy of ±1%; convert data from all monitoring devices to a common concentration, flow, pressure, and temperature measurement basis and calculate and record 15-minute and subsequent block one-hour average SO₂ emissions.

(c) The owner or operator shall install, operate, calibrate, and maintain dedicated instrumentation according to the manufacturers' specifications to continuously and separately monitor the flow rate and the total sulfur concentration of the inlet gas streams of EPN 66FL1, EPN 66FL2, EPN 66FL3, and EPN 66FL12, in accordance with the 40 CFR §60.107a(e) and (f)(1), regardless of whether these provisions otherwise apply or provide an exemption for any flare activities, as follows:

(1) monitor the total volumetric flow rate of gases routed to each flare using a separate dedicated totalizing gas flow meter with an accuracy of ±5%;

(2) monitor the temperature of gases routed to each flare using a separate temperature measurement device with an accuracy of ±1%; and

(3) monitor the sulfur content of the combined inlet flare gas stream as follows:

(A) using a separate dedicated analyzer capable of accurately measuring and recording total sulfur (including SO₂, hydrogen sulfide (H₂S), and organic sulfur compounds levels) with an accuracy of ±5% on a continuous basis, the sulfur concentration must be determined in accordance 40 CFR §60.107a(e)(1) regardless of applicability or exemptions, and determine hourly SO₂ emissions using the following equation; or

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(B) using a separate dedicated analyzer capable of accurately measuring and recording H₂S to an accuracy of ±5% on a continuous basis, determine the H₂S concentration in the flared gas stream, derive an inlet flare gas total sulfur concentration for each monitored hourly H₂S concentration in accordance 40 CFR §60.107a(e)(2) methodology regardless of applicability or exemptions, and calculate the SO₂ emissions from each flare for each operating hour using the following equation:

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(d) The owner or operator shall continuously monitor the flow rate, temperature, and total sulfur or H₂S concentration in the gases combusted by each affected EPN listed in §112.230(b)(6) and (7) of this title (relating to Applicability), in accordance with 40 CFR §60.107a(a), (e) and (f)(1), except for the SRU Incinerator (EPN 34I1) and SCOT SRU Incinerator (EPN 43I1) that must be monitored under §112.233(b), as follows:

(1) monitor the total volumetric fuel flow to each combustion device using a separate dedicated totalizing gas flow meter with an accuracy of ±5%; each fuel flow meter must be installed, calibrated, maintained, and operated per the manufacturer's recommendations and specifications;

(2) monitor the fuel temperature using a separate dedicated temperature monitor with an accuracy of ±1%; that is installed, calibrated, maintained, and operated according to the manufacturer's recommendations and specifications; if the fuel temperature does not vary by more than ±1% throughout a common fuel supply system, the fuel temperature for each affected source supplied by the fuel supply system may be monitored at a single location; and

(3) monitor the fuel sulfur content either directly with a total sulfur analyzer or by monitoring the surrogate H₂S concentration as follows:

(A) if a total sulfur analyzer is used, calculate the emissions using the following equation; or

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(B) if the H₂S concentration is monitored as a surrogate for the total sulfur content, calculate the SO₂ emissions as follows:

(i) collect at least one sample each month; the frequency of sampling may be reduced to no less than one time per calendar quarter if three consecutive monthly samples indicate that H₂S makes up 90.0 mole % or more of the total sulfur compounds in the fuel gas sample, and shall revert from quarterly to monthly when quarterly sample sulfur compounds consist of less than 90.0 mole % H₂S;

(ii) have the samples analyzed for total sulfur and H₂S concentrations;

(iii) use the following equation to calculate total SO₂ emissions.

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(iv) sum the emissions for each affected source in §112.230(b)(6) of this title as calculated in §112.233(b) and (d) of this section to determine compliance with the total EPN FLEX_R_CAP SO₂ hourly emission limit; and

(v) sum the emissions for each affected source in §112.230(b)(7) of this title as calculated in §112.233(d) of this title to determine compliance with the total EPN FLEX_MS_CAP SO₂ hourly emissions limit.

(e) Continuous monitoring data collected in accordance with requirements in this section 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 judgement, to obtain all missing or invalidated monitoring data for the remaining period the monitored emission point has emissions.

(f) 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 and the replacement of parametric monitoring with direct emissions monitoring with a CEMS 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 §112.233 adopted to be effective October 27, 2022, 47 TexReg 6985