Section 63.114 - [Effective 7/15/2024] Process vent provisions-monitoring requirements(a) Each owner or operator of a process vent that uses a combustion device to comply with the requirements in § 63.113(a)(1), (2), or (5) , or that uses a recovery device or recapture device to comply with the requirements in § 63.113(a)(2) , shall install monitoring equipment specified in paragraph (a)(1), (2), (3), (4), (5), or (6) of this section, depending on the type of device used. All monitoring equipment shall be installed, calibrated, maintained, and operated according to manufacturer's specifications or other written procedures that provide adequate assurance that the equipment would reasonably be expected to monitor accurately.(1) Where an incinerator is used, a temperature monitoring device equipped with a continuous recorder is required.(i) Where an incinerator other than a catalytic incinerator is used, a temperature monitoring device shall be installed in the firebox or in the ductwork immediately downstream of the firebox in a position before any substantial heat exchange occurs.(ii) Where a catalytic incinerator is used, temperature monitoring devices shall be installed in the gas stream immediately before and after the catalyst bed.(2) Where a flare is used, except as specified in § 63.108(a), the following monitoring equipment is required: A device (including but not limited to a thermocouple, ultra-violet beam sensor, or infrared sensor) capable of continuously detecting the presence of a pilot flame.(3) Where a boiler or process heater of less than 44 megawatts design heat input capacity is used, the following monitoring equipment is required: a temperature monitoring device in the firebox equipped with a continuous recorder. This requirement does not apply to gas streams that are introduced with primary fuel or are used as the primary fuel.(4) Where a scrubber is used with an incinerator, boiler, or process heater in the case of halogenated vent streams, the following monitoring equipment is required for the scrubber.(i) A pH monitoring device equipped with a continuous recorder shall be installed to monitor the pH of the scrubber effluent.(ii) A flow meter equipped with a continuous recorder shall be located at the scrubber influent for liquid flow. Gas flow rate shall be determined using one of the procedures specified in paragraphs (a)(4)(ii)(A) through (C) of this section. (A) The owner or operator may determine gas flow rate using the design blower capacity, with appropriate adjustments for pressure drop.(B) If the scrubber is subject to rules in 40 CFR parts 264 through 266 that have required a determination of the liquid to gas (L/G) ratio prior to the applicable compliance date for this subpart specified in § 63.100(k) , the owner or operator may determine gas flow rate by the method that had been utilized to comply with those rules. A determination that was conducted prior to the compliance date for this subpart may be utilized to comply with this subpart if it is still representative.(C) The owner or operator may prepare and implement a gas flow rate determination plan that documents an appropriate method which will be used to determine the gas flow rate. The plan shall require determination of gas flow rate by a method which will at least provide a value for either a representative or the highest gas flow rate anticipated in the scrubber during representative operating conditions other than startups, shutdowns, or malfunctions. The plan shall include a description of the methodology to be followed and an explanation of how the selected methodology will reliably determine the gas flow rate, and a description of the records that will be maintained to document the determination of gas flow rate. The owner or operator shall maintain the plan as specified in § 63.103(c) . For each source as defined in § 63.101 , on and after July 15, 2027, the phrase "other than startups, shutdowns, or malfunctions" in this paragraph no longer applies.(5) Where a recovery device or recapture device is used to comply with the requirements of § 63.113(a)(2) or (5) , the owner or operator shall utilize the appropriate monitoring device identified in paragraph (a)(5)(i), (ii), (iii), (iv), or (v) of this section. All monitoring equipment shall be installed, calibrated, and maintained according to the manufacturer's specifications or other written procedures that provide adequate assurance that the equipment would reasonably be expected to monitor accurately. (i) Install either an organic monitoring device equipped with a continuous recorder;(ii) Where an absorber is the final recovery device in the recovery system, a scrubbing liquid temperature monitoring device and a specific gravity monitoring device, each equipped with a continuous recorder shall be used;(iii) Where a condenser is the final recovery device in the recovery system, a condenser exit (product side) temperature monitoring device equipped with a continuous recorder shall be used;(iv) Except as specified in paragraph (a)(5)(v) of this section, where a carbon adsorber is the final recovery device in the recovery system, an integrating regeneration stream flow monitoring device having an accuracy of ±10 percent or better, capable of recording the total regeneration stream mass or volumetric flow for each regeneration cycle; and a carbon bed temperature monitoring device, capable of recording the carbon bed temperature after each regeneration and within 15 minutes of completing any cooling cycle shall be used.(v) Beginning no later than the compliance dates specified in § 63.100(k)(10) , if the owner or operator vents emissions through a closed vent system to an adsorber(s) that cannot be regenerated or a regenerative adsorber(s) that is regenerated offsite, then the owner or operator must install a system of two or more adsorber units in series and comply with the requirements specified in paragraphs (a)(5)(v)(A) through (C) of this section. (A) Conduct an initial performance test or design evaluation of the adsorber and establish the breakthrough limit and adsorber bed life.(B) Monitor the HAP or total organic compound (TOC) concentration through a sample port at the outlet of the first adsorber bed in series according to the schedule in paragraph (a)(5)(v)(C)(2) of this section. The owner or operator must measure the concentration of HAP or TOC using either a portable analyzer, in accordance with Method 21 of appendix A-7 to part 60 of this chapter using methane, propane, isobutylene, or the primary HAP being controlled as the calibration gas or Method 25A of part 60, appendix A-7, using methane, propane, or the primary HAP being controlled as the calibration gas.(C) Comply with paragraph (a)(5)(v)(C)(1) of this section and comply with the monitoring frequency according to paragraph (a)(5)(v)(C)(2) of this section.(1) The first adsorber in series must be replaced immediately when breakthrough, as defined in § 63.101 , is detected between the first and second adsorber. The original second adsorber (or a fresh canister) will become the new first adsorber and a fresh adsorber will become the second adsorber. For purposes of this paragraph, "immediately" means within 8 hours of the detection of a breakthrough for adsorbers of 55 gallons or less, and within 24 hours of the detection of a breakthrough for adsorbers greater than 55 gallons. The owner or operator must monitor at the outlet of the first adsorber within 3 days of replacement to confirm it is performing properly.(2) Based on the adsorber bed life established according to paragraph (a)(5)(v)(A) of this section and the date the adsorbent was last replaced, conduct monitoring to detect breakthrough at least monthly if the adsorbent has more than 2 months of life remaining, at least weekly if the adsorbent has between 2 months and 2 weeks of life remaining, and at least daily if the adsorbent has 2 weeks or less of life remaining.(6) Where sorbent injection is used, the following monitoring equipment is required for the sorbent injection system: (i) A sorbent injection rate monitoring device (e.g., weigh belt, weigh hopper, hopper flow measurement device) installed in a position that provides a representative measurement equipped with a continuous recorder to monitor the sorbent injection rate; and(ii) A flow measurement device equipped with a continuous recorder to monitor the carrier gas flow rate.(b) Except as specified in § 63.113(a)(4) , each owner or operator of a process vent with a TRE index value greater than 1.0 as specified under § 63.113(a)(3) or (d) that uses one or more recovery devices shall install either an organic monitoring device equipped with a continuous recorder or the monitoring equipment specified in paragraph (b)(1), (2), or (3) of this section, depending on the type of recovery device used. All monitoring equipment shall be installed, calibrated, and maintained according to the manufacturer's specifications or other written procedures that provide adequate assurance that the equipment would reasonably be expected to monitor accurately. Monitoring is not required for process vents with TRE index values greater than 4.0 as specified in § 63.113(e) . (1) Where an absorber is the final recovery device in the recovery system, a scrubbing liquid temperature monitoring device and a specific gravity monitoring device, each equipped with a continuous recorder shall be used;(2) Where a condenser is the final recovery device in the recovery system, a condenser exit (product side) temperature monitoring device equipped with a continuous recorder shall be used;(3) Where a carbon adsorber is the final recovery device in the recovery system, an integrating regeneration stream flow monitoring device having an accuracy of ±10 percent or better, capable of recording the total regeneration stream mass or volumetric flow for each regeneration cycle; and a carbon bed temperature monitoring device, capable of recording the carbon bed temperature after each regeneration and within 15 minutes of completing any cooling cycle shall be used.(c) An owner or operator of a process vent may request approval to monitor parameters other than those listed in paragraph (a) or (b) of this section. The request shall be submitted according to the procedures specified in § 63.151(f) or § 63.152(e) of this subpart. Approval shall be requested if the owner or operator: (1) Uses a combustion device other than an incinerator, boiler, process heater, or flare; or(2) Except as specified in § 63.113(a)(4) , maintains a TRE greater than 1.0 but less than or equal to 4.0 without a recovery device or with a recovery device other than the recovery devices listed in paragraphs (a) and (b) of this section; or(3) Uses one of the combustion or recovery or recapture devices listed in paragraphs (a) and (b) of this section, but seeks to monitor a parameter other than those specified in paragraphs (a) and (b) of this section.(d) The owner or operator of a process vent shall comply with paragraphs (d)(1) or (2) and (d)(3) of this section for any bypass line between the origin of the gas stream (i.e., at an air oxidation reactor, distillation unit, or reactor as identified in § 63.107(b) ) and the point where the gas stream reaches the process vent, as described in § 63.107 , that could divert the gas stream directly to the atmosphere. Except as specified in paragraph (d)(3)(ii) of this section, equipment such as low leg drains, high point bleeds, analyzer vents, open-ended valves or lines, and pressure relief valves needed for safety purposes are not subject to this paragraph (d). (1) Properly install, maintain, and operate a flow indicator that takes a reading at least once every 15 minutes. Records shall be generated as specified in § 63.118(a)(3) . The flow indicator shall be installed at the entrance to any bypass line that could divert the gas stream to the atmosphere; or(2) Secure the bypass line valve in the non-diverting position with a car-seal or a lock-and-key type configuration. A visual inspection of the seal or closure mechanism shall be performed at least once every month to ensure that the valve is maintained in the non-diverting position and the gas stream is not diverted through the bypass line(3) For each source as defined in § 63.101 , beginning no later than the compliance dates specified in § 63.100(k)(10) : (i) The use of a bypass line at any time on a closed vent system to divert emissions (subject to the emission standards in § 63.112 ) to the atmosphere or to a control device not meeting the requirements specified in this subpart is an emissions standards violation.(ii) The last sentence in paragraph (d) of this section no longer applies. Instead, the exemptions specified in paragraphs (d)(3)(ii)(A) and (B) of this section apply. (A) Except for pressure relief devices subject to § 63.165(e)(4) of subpart H of this part, equipment such as low leg drains and equipment subject to the requirements of subpart H of this part are not subject to this paragraph (d) of this section.(B) Open-ended valves or lines that use a cap, blind flange, plug, or second valve and follow the requirements specified in § 60.482-6(a)(2), (b), and (c) of this chapter or follow requirements codified in another regulation that are the same as § 60.482-6(a)(2), (b), and (c) are not subject to this paragraph (d).(e) The owner or operator shall establish a range that indicates proper operation of the control or recovery device for each parameter monitored under paragraphs (a), (b), and (c) of this section based on the results of the most recent performance test. In order to establish the range, the information required in § 63.152(b) shall be submitted in the Notification of Compliance Status or the operating permit application or amendment. The range may be based upon a prior performance test conducted for determining compliance with a regulation promulgated by the EPA, and the owner or operator is not required to conduct an initial performance test under § 63.116 , if the prior performance test was conducted using the same methods specified in § 63.116 and either no process changes have been made since the test, or the owner or operator can demonstrate that the results of the performance test, with or without adjustments, reliably demonstrate compliance despite process changes. Subsequent performance tests must be conducted according to § 63.103(b)(1) .59 FR 19468, Apr. 22, 1994, as amended at 62 FR 2745, Jan. 17, 1997; 66 FR 6930, Jan. 22, 2001