Section 63.491 - [Effective 7/15/2024] Batch front-end process vents-recordkeeping requirements(a)Group determination records for batch front-end process vents. Except as provided in paragraphs (a)(7) and (a)(8) of this section, each owner or operator of an affected source shall maintain the records specified in paragraphs (a)(1) through (a)(6) of this section for each batch front-end process vent subject to the group determination procedures of § 63.488 . Except for paragraph (a)(1) of this section, the records required to be maintained by this paragraph are limited to the information developed and used to make the group determination under §§ 63.488(b) through 63.488(g) , as appropriate. If an owner or operator did not need to develop certain information (e.g., annual average batch vent flow rate) to determine the group status, this paragraph does not require that additional information be developed. Paragraph (a)(9) of this section specifies the recordkeeping requirements for Group 2 batch front-end process vents that are exempt from the batch mass input limitation provisions, as allowed under § 63.487(h) . (1) An identification of each unique product that has emissions from one or more batch emission episodes venting from the batch front-end process vent, along with an identification of the single highest-HAP recipe for each product and the mass of HAP fed to the reactor for that recipe.(2) A description of, and an emission estimate for, each batch emission episode, and the total emissions associated with one batch cycle, as described in either paragraph (a)(2)(i) or (a)(2)(ii) of this section, as appropriate. (i) If the group determination is based on the expected mix of products, records shall include the emission estimates for the single highest-HAP recipe of each unique product identified in paragraph (a)(1) of this section that was considered in making the group determination under § 63.488 .(ii) If the group determination is based on the single highest-HAP recipe (considering all products produced or processed in the batch unit operation), records shall include the emission estimates for the single highest-HAP recipe.(3) Total annual uncontrolled TOC or organic HAP emissions, determined at the exit from the batch unit operation before any emission control, as determined in accordance with § 63.488(b) . (i) For Group 2 batch front-end process vents, emissions shall be determined at the batch mass input limitation.(ii) For Group 1 batch front-end process vents, emissions shall be those used to determine the group status of the batch front-end process vent.(4) The annual average batch vent flow rate for the batch front-end process vent as determined in accordance with § 63.488(e) .(5) The cutoff flow rate, determined in accordance with § 63.488(f) .(6) The results of the batch front-end process vent group determination, conducted in accordance with § 63.488(g) .(7) If a batch front-end process vent is subject to § 63.487(a) or § 63.487(b) , none of the records in paragraphs (a)(1) through (a)(6) of this section are required.(8) If the total annual emissions from the batch front-end process vent during the group determination are less than the appropriate level specified in § 63.488(d) , only the records in paragraphs (a)(1) through (a)(3) of this section are required.(9) For each Group 2 batch front-end process vent that is exempt from the batch mass input limitation provisions because it meets the criteria of § 63.487(h) , the records specified in paragraphs (a)(9)(i) and (ii) shall be maintained. (i) Documentation of the maximum design capacity of the EPPU; and(ii) The mass of HAP or material that can be charged annually to the batch unit operation at the maximum design capacity.(b)Compliance demonstration records. Each owner or operator of a batch front-end process vent or aggregate batch vent stream complying with § 63.487(a) or (b) , shall keep the following records, as applicable, readily accessible: (1) The annual mass emissions of halogen atoms in the batch front-end process vent or aggregate batch vent stream determined according to the procedures specified in § 63.488(h) .(2) If the owner or operator of a batch front-end process vent has chosen to comply with § 63.487(a)(2) , records documenting the batch cycle percent reduction as specified in § 63.490(c)(2) .(3) Except as specified in paragraph (b)(3)(iv) of this section, when using a flare to comply with § 63.487(a)(1) : (i) The flare design (i.e., steam-assisted, air-assisted, or non-assisted);(ii) All visible emission readings, heat content determinations, flow rate measurements, and exit velocity determinations made during the compliance determination required by § 63.504(c) ; and(iii) Periods when all pilot flames were absent.(iv) For each affected source as described in § 63.480 , beginning no later than the compliance dates specified in § 63.481(n) , paragraphs (b)(3)(i) through (b)(3)(iii) of this section no longer apply and instead the owner or operator of the affected source must keep the records specified in § 63.108(m) of subpart F of this part and § 63.508, readily accessible when using a flare to comply with § 63.487(a)(1) .(4) The following information when using a control device to meet the percent reduction requirement specified in § 63.487 (a)(2) or (b)(2) :(i) For an incinerator or non-combustion control device, the percent reduction of organic HAP or TOC achieved, as determined using the procedures specified in § 63.490(c) for batch front-end process vents and § 63.490(e) for aggregate batch vent streams;(ii) For a boiler or process heater, a description of the location at which the vent stream is introduced into the boiler or process heater;(iii) For a boiler or process heater with a design heat input capacity of less than 44 megawatts and where the process vent stream is introduced with combustion air or is used as a secondary fuel and is not mixed with the primary fuel, the percent reduction of organic HAP or TOC achieved, as determined using the procedures specified in § 63.490(c) for batch front-end process vents and § 63.490(e) for aggregate batch vent streams; and(iv) For a scrubber or other halogen reduction device following a combustion device to control halogenated batch front-end process vents or halogenated aggregate batch vent streams, the percent reduction of total hydrogen halides and halogens, as determined under § 63.490(d)(3) or the emission limit determined under § 63.490(d)(4) .(5) When complying with the 20 parts per million by volume outlet concentration standard specified in § 63.487(b)(2) , records of the outlet concentration of organic HAP or TOC on a dry basis. If supplemental combustion air is used to combust the emissions, the outlet concentration shall be corrected to 3 percent oxygen. If supplemental combustion air is not used, a correction to 3 percent oxygen is not required.(6) Records of the dioxins and furans concentration, as determined in § 63.490(g) .(c)Establishment of parameter monitoring level records. For each parameter monitored according to § 63.489(b) and Table 6 of this subpart, or for alternate parameters and/or parameters for alternate control devices monitored according to § 63.492(e) as allowed under § 63.489(c) , maintain documentation showing the establishment of the level that indicates proper operation of the control device as required by § 63.489(e) for parameters specified in § 63.489(b) and as required by § 63.506(f) for alternate parameters. This documentation shall include the parameter monitoring data used to establish the level.(d)Group 2 batch front-end process vent continuous compliance records. The owner or operator of a Group 2 batch front-end process vent shall comply with either paragraph (d)(1) or (d)(2) of this section, as appropriate. (1) The owner or operator of a Group 2 batch front-end process vent required to comply with § 63.487(g) shall keep the following records readily accessible: (i) Except as specified in paragraph (d)(1)(iii) of this section, records designating the established batch mass input limitation required by § 63.487(g)(1) and specified in § 63.490(f) .(ii) Records specifying the mass of HAP or material charged to the batch unit operation.(iii) For each affected source as described in § 63.480 , beginning no later than the compliance dates specified in § 63.481(n) , paragraph (d)(1)(i) of this section no longer applies.(2) The owner or operator of a Group 2 batch front-end process vent complying with § 63.487(f) shall keep the following records readily accessible: (i) Records designating the established batch mass input limitation required by § 63.487(f)(1) and specified in § 63.490(f) .(ii) Records specifying the mass of HAP or material charged to the batch unit operation.(e)Controlled batch front-end process vent continuous compliance records. Each owner or operator of a batch front-end process vent that has chosen to use a control device to comply with § 63.487(a) shall keep the following records readily accessible: (1) Continuous records of the equipment operating parameters specified to be monitored under § 63.489(b) as applicable, and listed in Table 6 of this subpart, or specified by the Administrator in accordance with § 63.492(e) as allowed under § 63.489(c) . These records shall be kept as specified under § 63.506(d) , except as specified in paragraphs (e)(1)(i) and (e)(1)(ii) of this section. (i) For flares, the records specified in Table 6 of this subpart shall be maintained in place of continuous records.(ii) For carbon adsorbers, the records specified in Table 6 of this subpart shall be maintained in place of batch cycle daily averages.(2) Records of the batch cycle daily average value of each continuously monitored parameter, except as provided in paragraphs (e)(2)(iii) of this section, as calculated using the procedures specified in paragraphs (e)(2)(i) and (e)(2)(ii) of this section. (i) The batch cycle daily average shall be calculated as the average of all parameter values measured for an operating day during those batch emission episodes, or portions thereof, in the batch cycle that the owner or operator has selected to control.(ii) Monitoring data recorded during periods of monitoring system breakdowns, repairs, calibration checks, and zero (low-level) and high-level adjustments shall not be included in computing the batch cycle daily averages. In addition, monitoring data recorded during periods of non-operation of the EPPU (or specific portion thereof) resulting in cessation of organic HAP emissions shall not be included in computing the batch cycle daily averages.(iii) If all recorded values for a monitored parameter during an operating day are above the minimum or below the maximum level established in accordance with § 63.489(e) , the owner or operator may record that all values were above the minimum or below the maximum level established, rather than calculating and recording a batch cycle daily average for that operating day.(3) Except as specified in paragraph (e)(6) of this section, hourly records of whether the flow indicator for bypass lines specified under § 63.489(d)(1) was operating and whether a diversion was detected at any time during the hour. Also, records of the times of all periods when the vent is diverted from the control device, or the flow indicator specified in § 63.489(d)(1) is not operating.(4) Except as specified in paragraph (e)(6) of this section, where a seal or closure mechanism is used to comply with § 63.489(d)(2) , hourly records of whether a diversion was detected at any time are not required. (i) For compliance with § 63.489(d)(2) , the owner or operator shall record whether the monthly visual inspection of the seals or closure mechanism has been done, and shall record the occurrence of all periods when the seal mechanism is broken, the bypass line damper or valve position has changed, or the key for a lock-and-key type configuration has been checked out, and records of any car-seal that has been broken.(5) Records specifying the times and duration of periods of monitoring system breakdowns, repairs, calibration checks, and zero (low-level) and high level adjustments. In addition, records specifying any other periods of process or control device operation when monitors are not operating.(6) For each flow event from a bypass line subject to the requirements in § 63.489(d) for each affected source as described in § 63.480 , beginning no later than the compliance dates specified in § 63.481(n) , the owner or operator must also maintain records sufficient to determine whether or not the detected flow included flow requiring control. For each flow event from a bypass line requiring control that is released either directly to the atmosphere or to a control device not meeting the requirements in this subpart, the owner or operator must include an estimate of the volume of gas, the concentration of organic HAP in the gas and the resulting emissions of organic HAP that bypassed the control device using process knowledge and engineering estimates.(f)Aggregate batch vent stream continuous compliance records. In addition to the records specified in paragraphs (b) and (c) of this section, each owner or operator of an aggregate batch vent stream using a control device to comply with § 63.487(b)(1) or (b)(2) shall keep the following records readily accessible:(1) Continuous records of the equipment operating parameters specified to be monitored under § 63.489(b) and listed in Table 6 of this subpart, as applicable, or specified by the Administrator in accordance with § 63.492(e) , as allowed under § 63.489(c) , with the exceptions listed in paragraphs (f)(1)(i) and (f)(1)(ii) of this section. (i) For flares, the records specified in Table 6 of this subpart shall be maintained in place of continuous records.(ii) For carbon adsorbers, the records specified in Table 6 of this subpart shall be maintained in place of daily averages.(2) Records of the daily average value of each continuously monitored parameter for each operating day determined according to the procedures specified in § 63.506(d) .(3) For demonstrating compliance with the monitoring of bypass lines as specified in § 63.489(d) , records as specified in paragraph (e)(3) or (4) of this section, and (e)(6) of this section as appropriate.(g) Documentation supporting the establishment of the batch mass input limitation shall include the information specified in paragraphs (g)(1) through (g)(5) of this section, as appropriate. (1) Identification of whether the purpose of the batch mass input limitation is to comply with § 63.487(f)(1) or (g)(1) .(2) Identification of whether the batch mass input limitation is based on the single highest-HAP recipe (considering all products) or on the expected mix of products for the batch front-end process vent as allowed under § 63.488(a)(1) .(3) Definition of the operating year, for the purposes of determining compliance with the batch mass input limitation.(4) If the batch mass input limitation is based on the expected mix of products, the owner or operator shall provide documentation that describes as many scenarios for differing mixes of products (i.e., how many of each type of product) as the owner or operator desires the flexibility to accomplish. Alternatively, the owner or operator shall provide a description of the relationship among the mix of products that will allow a determination of compliance with the batch mass input limitation under any number of scenarios.(5) The mass of HAP or material allowed to be charged to the batch unit operation per year under the batch mass input limitation.(h)Maintenance vent compliance records for batch front-end process vents. For each maintenance vent opening subject to the requirements of § 63.487(i) , owners and operators must keep the applicable records specified in paragraphs (h)(1) through (5) of this section. (1) Owners and operators must maintain standard site procedures used to deinventory equipment for safety purposes (e.g., hot work or vessel entry procedures) to document the procedures used to meet the requirements in § 63.487(i) . The current copy of the procedures must be retained and available on-site at all times. Previous versions of the standard site procedures, as applicable, must be retained for five years.(2) If complying with the requirements of § 63.487(i)(1)(i) , and the concentration of the vapor at the time of the vessel opening exceeds 10 percent of its LEL, identification of the maintenance vent, the process units or equipment associated with the maintenance vent, the date of maintenance vent opening, and the concentration of the vapor at the time of the vessel opening.(3) If complying with the requirements of § 63.487(i)(1)(ii) , and either the vessel pressure at the time of the vessel opening exceeds 5 psig or the concentration of the vapor at the time of the active purging was initiated exceeds 10 percent of its LEL, identification of the maintenance vent, the process units or equipment associated with the maintenance vent, the date of maintenance vent opening, the pressure of the vessel or equipment at the time of discharge to the atmosphere and, if applicable, the concentration of the vapors in the equipment when active purging was initiated.(4) If complying with the requirements of § 63.487(i)(1)(iii) , records of the estimating procedures used to determine the total quantity of VOC in the equipment and the type and size limits of equipment that contain less than 50 pounds of VOC at the time of maintenance vent opening. For each maintenance vent opening that contains greater than 50 pounds of VOC for which the deinventory procedures specified in paragraph (h)(1) of this section are not followed or for which the equipment opened exceeds the type and size limits established in the records specified in this paragraph (h)(4), records that identify the maintenance vent, the process units or equipment associated with the maintenance vent, the date of maintenance vent opening, and records used to estimate the total quantity of VOC in the equipment at the time the maintenance vent was opened to the atmosphere.(5) If complying with the requirements of § 63.487(i)(1)(iv) , identification of the maintenance vent, the process units or equipment associated with the maintenance vent, records documenting actions taken to comply with other applicable alternatives and why utilization of this alternative was required, the date of maintenance vent opening, the equipment pressure and concentration of the vapors in the equipment at the time of discharge, an indication of whether active purging was performed and the pressure of the equipment during the installation or removal of the blind if active purging was used, the duration the maintenance vent was open during the blind installation or removal process, and records used to estimate the total quantity of VOC in the equipment at the time the maintenance vent was opened to the atmosphere for each applicable maintenance vent opening.62 FR 46925, Sept. 5, 1996, as amended at 64 FR 11542, Mar. 9, 1999; 65 FR 38063, June 19, 2000; 76 FR 22589, Apr. 21, 2011