--- kind: "range" citation: "40 C.F.R. §§ 63.485–63.501" title: "40" from: "63.485" to: "63.501" count: 17 url: "https://uscodex.org/cfr/40/63.485..63.501" --- # §63.485. Continuous front-end process vent provisions. - (a) For each continuous front-end process vent located at an affected source, the owner or operator shall comply with the requirements of [§§ 63.113 through 63.118](/cfr/40/63.113..63.118.md), except as provided for in [paragraphs (b) through (z)](#b..z) of this section. The owner or operator of continuous front-end process vents that are combined with one or more batch front-end process vents shall comply with paragraph [(o)](#o) or [(p)](#p) of this section. - (b) When the term “process vent” is used in [§§ 63.113 through 63.118](/cfr/40/63.113..63.118.md), the term “continuous front-end process vent,” and the definition of this term in [§ 63.482](/cfr/40/63.482.md) shall apply for the purposes of this subpart. - (c) When the term “halogenated process vent” is used in [§§ 63.113 through 63.118](/cfr/40/63.113..63.118.md), the term “halogenated continuous front-end process vent,” and the definition of this term in [§ 63.482](/cfr/40/63.482.md) shall apply for the purposes of this subpart. - (d) When the term “Group 1 process vent” is used in [§§ 63.113 through 63.118](/cfr/40/63.113..63.118.md), the term “Group 1 continuous front-end process vent,” and the definition of this term in [§ 63.482](/cfr/40/63.482.md) shall apply for the purposes of this subpart. - (e) When the term “Group 2 process vent” is used in [§§ 63.113 through 63.118](/cfr/40/63.113..63.118.md), the term “Group 2 continuous front-end process vent,” and the definition of this term in [§ 63.482](/cfr/40/63.482.md) shall apply for the purposes of this subpart. - (f) When December 31, 1992 (i.e., the proposal date for [subpart G](/cfr/40/subpartG.md) of this part) is referred to in [§ 63.113](/cfr/40/63.113.md), June 12, 1995 shall instead apply, for the purposes of this subpart. - (g) When [§§ 63.151(f)](/cfr/40/63.151.md?p=f), alternative monitoring parameters, and 63.152(e), submission of an operating permit, are referred to in §§ [63.114(c)](/cfr/40/63.114.md?p=c) and [63.117(e)](/cfr/40/63.117.md?p=e), [63.506(f)](/cfr/40/63.506.md?p=f), alternative monitoring parameters, and [§ 63.506(e)(8)](/cfr/40/63.506.md?p=e-8), submission of an operating permit, respectively, shall apply for the purposes of this subpart. - (h) When the Notification of Compliance Status requirements contained in [§ 63.152(b)](/cfr/40/63.152.md?p=b) are referred to in §§ [63.114](/cfr/40/63.114.md), [63.117](/cfr/40/63.117.md), and [63.118](/cfr/40/63.118.md), the Notification of Compliance Status requirements contained in [§ 63.506(e)(5)](/cfr/40/63.506.md?p=e-5) shall apply for the purposes of this subpart. - (i) When the Periodic Report requirements contained in [§ 63.152(c)](/cfr/40/63.152.md?p=c) are referred to in §§ [63.117](/cfr/40/63.117.md) and [63.118](/cfr/40/63.118.md), the Periodic Report requirements contained in [§ 63.506(e)(6)](/cfr/40/63.506.md?p=e-6) shall apply for the purposes of this subpart. - (j) When the definition of excursion in [§ 63.152(c)(2)(ii)(A)](/cfr/40/63.152.md?p=c-2-ii-A) is referred to in [§ 63.118(f)(2)](/cfr/40/63.118.md?p=f-2), the definition of excursion in § [63.505(g)](/cfr/40/63.505.md?p=g) and [(h)](/cfr/40/63.505.md?p=h) shall apply for the purposes of this subpart. - (k) When [§ 63.114(e)](/cfr/40/63.114.md?p=e) or [§ 63.117(f)](/cfr/40/63.117.md?p=f) specifies that an owner or operator shall submit the information required in [§ 63.152(b)](/cfr/40/63.152.md?p=b) in order to establish the parameter monitoring range, the owner or operator of an affected source shall comply with the provisions of [§ 63.505](/cfr/40/63.505.md) for establishing the parameter monitoring level and shall comply with [§ 63.506(e)(5)](/cfr/40/63.506.md?p=e-5) for the purposes of reporting information related to the establishment of the parameter monitoring level, for the purposes of this subpart. Further, the term “level” shall apply whenever the term “range” is used in §§ [63.114](/cfr/40/63.114.md), [63.117](/cfr/40/63.117.md), and [63.118](/cfr/40/63.118.md). - (l) When reports of process changes are required under § [63.118(g)](/cfr/40/63.118.md?p=g), [(h)](/cfr/40/63.118.md?p=h), [(i)](/cfr/40/63.118.md?p=i), or [(j)](/cfr/40/63.118.md?p=j), [paragraphs (l)(1) through (l)(4)](#l-1..l-4) of this section shall apply for the purposes of this subpart. In addition, for the purposes of this subpart [paragraph (l)(5)](#l-5) of this section applies, and [§ 63.118(k)](/cfr/40/63.118.md?p=k) does not apply to owners or operators of affected sources. - (1) For the purposes of this subpart, whenever a process change, as defined in [§ 63.115(e)](/cfr/40/63.115.md?p=e), is made that causes a Group 2 continuous front-end process vent to become a Group 1 continuous front-end process vent, the owner or operator shall submit a report within 180 days after the process change is made or with the next Periodic Report, whichever is later. A description of the process change shall be submitted with the report of the process change, and the owner or operator of the affected source shall comply with the Group 1 provisions in [§§ 63.113 through 63.118](/cfr/40/63.113..63.118.md) in accordance with § [63.480(i)(2)(ii)](/cfr/40/63.480.md?p=i-2-ii) or [(i)(2)(iii)](/cfr/40/63.480.md?p=i-2-iii), as applicable. - (2) Whenever a process change, as defined in [§ 63.115(e)](/cfr/40/63.115.md?p=e), is made that causes a Group 2 continuous front-end process vent with a TRE greater than 4.0 to become a Group 2 continuous front-end process vent with a TRE less than 4.0, the owner or operator shall submit a report within 180 days after the process change is made or with the next Periodic Report, whichever is later. A description of the process change shall be submitted with the report of the process change, and the owner or operator shall comply with the provisions in [§ 63.113(d)](/cfr/40/63.113.md?p=d) by the dates specified in [§ 63.481](/cfr/40/63.481.md). - (3) Whenever a process change, as defined in [§ 63.115(e)](/cfr/40/63.115.md?p=e), is made that causes a Group 2 continuous front-end process vent with a flow rate less than 0.005 standard cubic meter per minute (scmm) to become a Group 2 continuous front-end process vent with a flow rate of 0.005 scmm or greater and a TRE index value less than or equal to 4.0, the owner or operator shall submit a report within 180 days after the process change is made or with the next Periodic Report, whichever is later. A description of the process change shall be submitted with the report of the process change, and the owner or operator shall comply with the provisions in [§ 63.113(d)](/cfr/40/63.113.md?p=d) by the dates specified in [§ 63.481](/cfr/40/63.481.md). - (4) Whenever a process change, as defined in [§ 63.115(e)](/cfr/40/63.115.md?p=e), is made that causes a Group 2 continuous front-end process vent with an organic HAP concentration less than 50 parts per million by volume (ppmv) to become a Group 2 continuous front-end process vent with an organic HAP concentration of 50 ppmv or greater and a TRE index value less than or equal to 4.0, the owner or operator shall submit a report within 180 days after the process change is made or with the next Periodic Report, whichever is later. A description of the process change shall be submitted with the report of the process change, and the owner or operator shall comply with the provisions in [§ 63.113(d)](/cfr/40/63.113.md?p=d) by the dates specified in [§ 63.481](/cfr/40/63.481.md). - (5) The owner or operator is not required to submit a report of a process change if one of the conditions listed in paragraphs [(l)(5)(i)](#l-5-i), [(l)(5)(ii)](#l-5-ii), [(l)(5)(iii)](#l-5-iii), or [(l)(5)(iv)](#l-5-iv) of this section is met. - (i) The change does not meet the description of a process change in [§ 63.115(e)](/cfr/40/63.115.md?p=e); - (ii) The vent stream flow rate is recalculated according to [§ 63.115(e)](/cfr/40/63.115.md?p=e) and the recalculated value is less than 0.005 standard cubic meter per minute; - (iii) The organic HAP concentration of the vent stream is recalculated according to [§ 63.115(e)](/cfr/40/63.115.md?p=e) and the recalculated value is less than 50 parts per million by volume; or - (iv) The TRE index value is recalculated according to [§ 63.115(e)](/cfr/40/63.115.md?p=e) and the recalculated value is greater than 4.0. - (m) When [§ 63.118](/cfr/40/63.118.md) (periodic reporting and recordkeeping requirements) refers to [§ 63.152(f)](/cfr/40/63.152.md?p=f), the recordkeeping requirements in [§ 63.506(d)](/cfr/40/63.506.md?p=d) shall apply for the purposes of this subpart. - (n) When §§ [63.115](/cfr/40/63.115.md) and [63.116](/cfr/40/63.116.md) refer to Table 2 of [subpart F](/cfr/40/subpartF.md) of this part, the owner or operator is only required to consider organic HAP listed on Table 5 of this subpart, for the purposes of this subpart. - (o) If a batch front-end process vent or aggregate batch vent stream is combined with a continuous front-end process vent, the owner or operator of the affected source containing the combined vent stream shall comply with [paragraph (o)(1)](#o-1); with [paragraph (o)(2)](#o-2) and with paragraph [(o)(3)](#o-3) or [(o)(4)](#o-4); or with [paragraph (o)(5)](#o-5) of this section, as appropriate. - (1) If a batch front-end process vent or aggregate batch vent stream is combined with a Group 1 continuous front-end process vent prior to the combined vent stream being routed to a control device, the owner or operator of the affected source containing the combined vent stream shall comply with the requirements in paragraph [(o)(1)(i)](#o-1-i) or [(o)(1)(ii)](#o-1-ii) of this section. - (i) All requirements for a Group 1 process vent stream in [§§ 63.113 through 63.118](/cfr/40/63.113..63.118.md), except as otherwise provided in this section. As specified in [§ 63.504(a)(1)](/cfr/40/63.504.md?p=a-1), performance tests shall be conducted at maximum representative operating conditions. For the purpose of conducting a performance test on a combined vent stream, maximum representative operating conditions shall be when batch emission episodes are occurring that result in the highest organic HAP emission rate (for the combined vent stream) that is achievable during one of the periods listed in [§ 63.504(a)(1)(i)](/cfr/40/63.504.md?p=a-1-i) or [§ 63.504(a)(1)(ii)](/cfr/40/63.504.md?p=a-1-ii), without causing any of the situations described in [paragraphs (o)(1)(i)(A) through (o)(1)(i)(C)](#o-1-i-A..o-1-i-C) of this section to occur. - (A) Causing damage to equipment; - (B) Necessitating that the owner or operator make product that does not meet an existing specification for sale to a customer; or - (C) **Necessitating that the owner or operator make product in excess of demand.** - (ii) Comply with the provisions in [§ 63.483(b)(1)](/cfr/40/63.483.md?p=b-1), as allowed under [§ 63.483(b)](/cfr/40/63.483.md?p=b). - (2) If a batch front-end process vent or aggregate batch vent stream is combined with a continuous front-end process vent prior to the combined vent stream being routed to a recovery device, the TRE index value for the combined vent stream shall be calculated at the exit of the last recovery device. The TRE shall be calculated during periods when one or more batch emission episodes are occurring that result in the highest organic HAP emission rate (in the combined vent stream that is being routed to the recovery device) that is achievable during the 6-month period that begins 3 months before and ends 3 months after the TRE calculation, without causing any of the situations described in [paragraphs (o)(2)(i) through (o)(2)(iii)](#o-2-i..o-2-iii) of this section to occur. - (i) Causing damage to equipment; - (ii) Necessitating that the owner or operator make product that does not meet an existing specification for sale to a customer; or - (iii) **Necessitating that the owner or operator make product in excess of demand.** - (3) If the combined vent stream described in [paragraph (o)(2)](#o-2) of this section meets the requirements in paragraphs [(o)(3)(i)](#o-3-i), [(o)(3)(ii)](#o-3-ii), and [(o)(3)(iii)](#o-3-iii) of this section, the combined vent stream shall be subject to the requirements for Group 1 process vents in [§§ 63.113 through 63.118](/cfr/40/63.113..63.118.md), except as otherwise provided in this section, as applicable. Performance tests for the combined vent stream shall be conducted at maximum representative operating conditions, as described in [paragraph (o)(1)](#o-1) of this section. - (i) The TRE index value of the combined stream is less than or equal to 1.0; - (ii) The flow rate of the combined vent stream is greater than or equal to 0.005 standard cubic meter per minute; and - (iii) The total organic HAP concentration is greater than or equal to 50 parts per million by volume for the combined vent stream. - (4) If the combined vent stream described in [paragraph (o)(2)](#o-2) of this section meets the requirements in paragraph [(o)(4)(i)](#o-4-i), [(ii)](#o-4-ii), or [(iii)](#o-4-iii) of this section, the combined vent stream shall be subject to the requirements for Group 2 process vents in [§§ 63.113 through 63.118](/cfr/40/63.113..63.118.md), except as otherwise provided in this section, as applicable. - (i) The TRE index value of the combined vent stream is greater than 1.0; - (ii) The flow rate of the combined vent stream is less than 0.005 standard cubic meter per minute; or - (iii) The total organic HAP concentration is less than 50 parts per million by volume for the combined vent stream. - (5) If a batch front-end process vent or aggregate batch vent stream is combined with a Group 2 continuous front-end process vent, the owner or operator shall comply with the requirements in either paragraph [(o)(5)(i)](#o-5-i) or [(o)(5)(ii)](#o-5-ii) of this section. - (i) The owner or operator shall comply with the requirements in [§§ 63.113 through 63.118](/cfr/40/63.113..63.118.md) for Group 1 process vents; or - (ii) The owner or operator shall comply with [§ 63.487(e)(2)](/cfr/40/63.487.md?p=e-2) for batch front-end process vents and aggregate batch vent streams. - (p) If any gas stream that originates outside of an affected source that is subject to this subpart is normally conducted through the same final recovery device as any continuous front-end process vent stream subject to this subpart, the combined vent stream shall comply with all requirements in [§§ 63.113 through 63.118](/cfr/40/63.113..63.118.md), except as otherwise provided in this section, as applicable. - (1) Instead of measuring the vent stream flow rate at the sampling site specified in [§ 63.115(b)(1)](/cfr/40/63.115.md?p=b-1), the sampling site for vent stream flow rate shall be prior to the final recovery device and prior to the point at which the gas stream that is not controlled under this subpart is introduced into the combined vent stream. - (2) Instead of measuring total organic HAP or TOC concentrations at the sampling site specified in [§ 63.115(c)(1)](/cfr/40/63.115.md?p=c-1), the sampling site for total organic HAP or TOC concentration shall be prior to the final recovery device and prior to the point at which the gas stream that is not controlled under this subpart is introduced into the combined vent stream. - (3) Except as specified in [paragraph (p)(5)](#p-5) of this section, the efficiency of the final recovery device (determined according to [paragraph (p)(4)](#p-4) of this section) shall be applied to the total organic HAP or TOC concentration measured at the sampling site described in [paragraph (p)(2)](#p-2) of this section to determine the exit concentration. This exit concentration of total organic HAP or TOC shall then be used to perform the calculations outlined in [§ 63.115(d)(2)(iii)](/cfr/40/63.115.md?p=d-2-iii) and [§ 63.115(d)(2)(iv)](/cfr/40/63.115.md?p=d-2-iv), for the combined vent stream exiting the final recovery device. - (4) The efficiency of the final recovery device is determined by measuring the total organic HAP or TOC concentration using Method 18 or 25A, [40 CFR part 60](/cfr/40/part60.md), appendix A, at the inlet to the final recovery device after the introduction of any gas stream that is not controlled under this subpart, and at the outlet of the final recovery device. - (5) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n), the last sentence in [paragraph (p)(3)](#p-3) of this section: “This exit concentration of total organic HAP or TOC shall then be used to perform the calculations outlined in [§ 63.115(d)(2)(iii)](/cfr/40/63.115.md?p=d-2-iii) and [§ 63.115(d)(2)(iv)](/cfr/40/63.115.md?p=d-2-iv), for the combined vent stream exiting the final recovery device.” no longer applies. - (q) Group 1 halogenated continuous front-end process vents must comply with the provisions of [§ 63.113(a)(1)(ii)](/cfr/40/63.113.md?p=a-1-ii) and [§ 63.113(c)](/cfr/40/63.113.md?p=c), with the exceptions noted in paragraphs [(q)(1)](#q-1) and [(2)](#q-2) of this section. - (1) Group 1 halogenated continuous front-end process vents at existing affected sources producing butyl rubber or ethylene propylene rubber using a solution process are exempt from the provisions of [§ 63.113(a)(1)(ii)](/cfr/40/63.113.md?p=a-1-ii) and [§ 63.113(c)](/cfr/40/63.113.md?p=c) if the conditions in paragraphs [(q)(1)(i)](#q-1-i) and [(ii)](#q-1-ii) of this section are met, and shall comply with the requirements in [paragraphs (q)(1)(iii) through (vi)](#q-1-iii..q-1-vi) of this section. Group 1 halogenated continuous front-end process vents at new affected sources producing butyl rubber or ethylene propylene rubber using a solution process are not exempt from [§ 63.113(a)(1)(ii)](/cfr/40/63.113.md?p=a-1-ii) and [§ 63.113(c)](/cfr/40/63.113.md?p=c). - (i) If the halogenated continuous front-end process vent stream was controlled by a combustion device prior to June 12, 1995; and - (ii) Except as specified in [paragraph (q)(3)](#q-3) of this section, if the requirements of [§ 63.113(a)(2)](/cfr/40/63.113.md?p=a-2); [§ 63.113(a)(3)](/cfr/40/63.113.md?p=a-3); [§ 63.113(b)](/cfr/40/63.113.md?p=b) and the associated testing requirements in [§ 63.116](/cfr/40/63.116.md); or [§ 63.11(b)](/cfr/40/63.11.md?p=b) and [§ 63.504(c)](/cfr/40/63.504.md?p=c) are met. - (iii) The average HCl emissions from all front-end process operations at affected sources producing butyl rubber and ethylene propylene rubber using a solution process shall not exceed the limits determined in accordance with paragraphs [(q)(1)(iii)(A)](#q-1-iii-A) and [(B)](#q-1-iii-B) of this section for any consecutive 12-month period. The specific limitation for each elastomer type shall be determined based on the calculation or the emissions level provided in paragraphs [(q)(1)(iii)(A)](#q-1-iii-A) and [(B)](#q-1-iii-B) of this section divided by the base year elastomer product that leaves the stripping operation (or the reactor(s), if the plant has no stripper(s)). The limitation shall be calculated and submitted in accordance with [paragraph (q)(1)(iv)](#q-1-iv) of this section. - (A) For butyl rubber, the HCl emission limitation shall be calculated using the following equation: - (B) For ethylene propylene rubber using a solution process, the HCl emission limitation, in units of Mg HCl emissions per Mg of ethylene propylene rubber produced, shall be calculated by dividing 27 Mg/yr by the mass of ethylene propylene rubber produced in 2010, in Mg. - (iv) If the front-end process operation is subject to a HCl emission limitation in [paragraph (q)(1)(iii)](#q-1-iii) of this section, the owner and operator must submit the information specified in paragraphs [(q)(1)(iv)(A)](#q-1-iv-A) and [(B)](#q-1-iv-B) of this section. - (A) The applicable HCl emission limitation determined in accordance with paragraphs [(q)(1)(iii)(A)](#q-1-iii-A) and [(B)](#q-1-iii-B) of this section shall be submitted no later than 180 days from the date of publication of the final rule amendments in the Federal Register. - (B) Beginning with the first periodic report required to be submitted by [§ 63.506(e)(6)](/cfr/40/63.506.md?p=e-6) that is at least 13 months after the compliance date, the total mass of HCl emitted for each of the rolling 12-month periods in the reporting period divided by the total mass of elastomer produced during the corresponding 12-month period, determined in accordance with [paragraph (q)(1)(v)](#q-1-v) of this section. - (v) Compliance with the HCl emission limitations determined in accordance with [paragraph (q)(1)(iii)](#q-1-iii) of this section shall be demonstrated in accordance with [paragraphs (q)(1)(v)(A) through (E)](#q-1-v-A..q-1-v-E) of this section. - (A) Calculate your HCl emission limitation in accordance with paragraphs [(q)(1)(iii)(A)](#q-1-iii-A) and [(B)](#q-1-iii-B) of this section, as applicable, record it, and submit it in accordance with [paragraph (q)(1)(iv)](#q-1-iv) of this section. - (B) Each month, calculate and record the HCl emissions from all front-end process operations using engineering assessment. Engineering assessment includes, but is not limited to, the following: (1) Use of material balances; (2) Estimation of flow rate based on physical equipment design, such as pump or blower capacities; (3) Estimation of HCl concentrations based on saturation conditions; and (4) Estimation of HCl concentrations based on grab samples of the liquid or vapor. - (C) **Each month, record the mass of elastomer product produced.** - (D) Each month, calculate and record the sum of the HCl emissions and the mass of elastomer produced for the previous calendar 12-month period. - (E) Each month, divide the total mass of HCl emitted for the previous calendar 12-month period by the total mass of elastomer produced during this 12-month period. This value must be recorded in accordance with [paragraph (q)(1)(vi)](#q-1-vi) of this section and reported in accordance with [paragraph (q)(1)(iv)](#q-1-iv) of this section. - (vi) If the front-end process operation is subject to an HCl emission limitation in [paragraph (q)(1)(iii)](#q-1-iii) of this section, the owner or operator shall maintain the records specified in [paragraphs (q)(1)(vi)(A) through (D)](#q-1-vi-A..q-1-vi-D) of this section. - (A) The applicable HCl emission limitation determined in accordance with paragraphs [(q)(1)(iii)(A)](#q-1-iii-A) and [(B)](#q-1-iii-B) of this section. - (B) The HCl emissions from all front-end process operations for each month, along with documentation of all calculations, and other information used in the engineering assessment to estimate these emissions. - (C) **The mass of elastomer product produced each month.** - (D) The total mass of HCl emitted for each 12-month period divided by the total mass of elastomer produced during the 12-month period, determined in accordance with [paragraph (q)(1)(v)](#q-1-v) of this section. - (2) Except as specified in [paragraph (q)(3)](#q-3) of this section, Group 1 halogenated continuous front-end process vents at new and existing affected sources producing an elastomer using a gas-phased reaction process, provided that the requirements of [§ 63.113(a)(2)](/cfr/40/63.113.md?p=a-2); [§ 63.113(a)(3)](/cfr/40/63.113.md?p=a-3); [§ 63.113(b)](/cfr/40/63.113.md?p=b) and the associated testing requirements in [§ 63.116](/cfr/40/63.116.md); or [§ 63.11(b)](/cfr/40/63.11.md?p=b) and [§ 63.504(c)](/cfr/40/63.504.md?p=c) are met. - (3) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n), paragraphs [(q)(1)(ii)](#q-1-ii) and (q)(2) of this section no longer apply. Instead, the requirements of [§ 63.113(a)(2)](/cfr/40/63.113.md?p=a-2); [§§ 63.113(b)](/cfr/40/63.113.md?p=b) and the associated testing requirements in [§ 63.116](/cfr/40/63.116.md); or [§ 63.508](/cfr/40/63.508.md) must be met. - (r) The compliance date for continuous front-end process vents subject to the provisions of this section is specified in [§ 63.481](/cfr/40/63.481.md). - (s) **Internal combustion engines.** In addition to the three options for the control of a Group 1 continuous front-end process vent listed in [§ 63.113(a)(1) through (3)](/cfr/40/63.113.md?p=a-1..a-3), except as specified in [§ 63.113(a)(4)](/cfr/40/63.113.md?p=a-4) of [subpart G](/cfr/40/subpartG.md) of this part, an owner or operator will be permitted to route emissions of organic HAP to an internal combustion engine, provided the conditions listed in [paragraphs (s)(1) through (s)(5)](#s-1..s-5) of this section are met. - (1) The vent stream routed to the internal combustion engine shall not be a halogenated continuous front-end process vent stream. - (2) **The organic HAP is introduced with the primary fuel.** - (3) The internal combustion engine is operating at all times that organic HAP emissions are being routed to it. The owner or operator shall demonstrate that the internal combustion engine is operating by continuously monitoring the on/off status of the internal combustion engine. - (4) The owner or operator shall maintain hourly records verifying that the internal combustion engine was operating at all times that emissions were routed to it. - (5) The owner or operator shall include in the Periodic Report a report of all times that the internal combustion engine was not operating while emissions were being routed to it. Include the start date and time and end date and time for all such periods. - (6) If an internal combustion engine meeting the requirements of [paragraphs (s)(1) through (5)](#s-1..s-5) of this section is used to comply with the provisions of [§ 63.113(a)](/cfr/40/63.113.md?p=a), the internal combustion engine is exempt from the source testing requirements of [§ 63.116](/cfr/40/63.116.md). - (t) When the provisions of § [63.116(c)(3)](/cfr/40/63.116.md?p=c-3) and [(4)](/cfr/40/63.116.md?p=c-4) specify that Method 18 of appendix A-6 to [40 CFR part 60](/cfr/40/part60.md) must be used, Method 18 or Method 25A of appendices A-6 and A-7 to [40 CFR part 60](/cfr/40/part60.md), respectively, may be used for the purposes of this subpart. ASTM D6420-18 (incorporated by reference, see [§ 63.14](/cfr/40/63.14.md)) may also be used in lieu of Method 18, if the target compounds are all known and are all listed in [Section 1.1](/cfr/40/1.1.md) of ASTM D6420-18 as measurable; ASTM D6420-18 must not be used for methane and ethane; and ASTM D6420-18 may not be used as a total VOC method. The use of Method 25A must conform with the requirements in paragraphs [(t)(1)](#t-1) and [(2)](#t-2) of this section. - (1) The organic HAP used as the calibration gas for Method 25A of appendix A-7 to [40 CFR part 60](/cfr/40/part60.md) must be the single organic HAP representing the largest percent by volume of the emissions. - (2) [Reserved] - (u) In [§ 63.116(a)](/cfr/40/63.116.md?p=a), instead of the reference to [§ 63.11(b)](/cfr/40/63.11.md?p=b), the requirements in [§ 63.504(c)](/cfr/40/63.504.md?p=c) shall apply. - (v) When a combustion device is used to comply with the 20 parts per million by volume outlet concentration standard specified in [§ 63.113(a)(2)](/cfr/40/63.113.md?p=a-2), the correction to 3 percent oxygen is only required when supplemental combustion air is used to combust the emissions, for the purposes of this subpart. In addition, the correction to 3 percent oxygen specified in § [63.116(c)(3)](/cfr/40/63.116.md?p=c-3) and [(c)(3)(iii)](/cfr/40/63.116.md?p=c-3-iii) is only required when supplemental combustion air is used to combust the emissions, for the purposes of this subpart. Finally, when a combustion device is used to comply with the 20 parts per million by volume outlet concentration standard specified in [§ 63.113(a)(2)](/cfr/40/63.113.md?p=a-2), an owner or operator shall record and report the outlet concentration required in § [63.117(a)(4)(ii)](/cfr/40/63.117.md?p=a-4-ii) and [(a)(4)(iv)](/cfr/40/63.117.md?p=a-4-iv) corrected to 3 percent oxygen when supplemental combustion air is used to combust the emissions, for the purposes of this subpart. When supplemental combustion air is not used to combust the emissions, an owner or operator may record and report the outlet concentration required in § [63.117(a)(4)(ii)](/cfr/40/63.117.md?p=a-4-ii) and [(a)(4)(iv)](/cfr/40/63.117.md?p=a-4-iv) on an uncorrected basis or corrected to 3 percent oxygen, for the purposes of this subpart. - (w) **Shutdown.** - (1) During periods of shutdown, a Group 1 continuous front-end process vent at an existing affected source producing butyl rubber or ethylene propylene rubber using a solution process must be routed to a flare until either the organic HAP concentration in the vent is less than 50 ppmv, or the vent pressure is below 103.421 kPa. - (x) Owners and operators of affected sources must make the substitutions as specified in [paragraphs (x)(1) through (4)](#x-1..x-4) of this section: - (1) Substitute “For each affected source as described in [§ 63.480](/cfr/40/63.480.md)” for each occurrence of the phrase “For each source as defined in [§ 63.101](/cfr/40/63.101.md)”. - (2) Substitute “beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n)” for each occurrence of the phrase “beginning no later than the compliance dates specified in [§ 63.100(k)(10)](/cfr/40/63.100.md?p=k-10)”. - (3) Substitute “owners and operators of affected sources as described in [§ 63.480](/cfr/40/63.480.md)” for each occurrence of the phrase “owners and operators of sources as defined in [§ 63.101](/cfr/40/63.101.md)”. - (4) Substitute “[§ 63.508](/cfr/40/63.508.md)” for each occurrence of “[§ 63.108](/cfr/40/63.108.md)”. - (y) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(o)](/cfr/40/63.481.md?p=o), if the Group 1 or Group 2 continuous front-end process vent contains chloroprene such that it is considered to be in chloroprene service, as defined in [§ 63.482](/cfr/40/63.482.md), then the owner or operator must comply with the requirements of [paragraphs (y)(1) through (4)](#y-1..y-4) of this section in addition to all other applicable requirements specified in [§ 63.483](/cfr/40/63.483.md) and elsewhere in this section. - (1) Reduce emissions of chloroprene by venting emissions through a closed vent system to a non-flare control device that reduces chloroprene by greater than or equal to 98 percent by weight, or to a concentration less than 1 ppmv for each process vent or to less than 5 pounds per year for all combined process vents within the process. If a combustion device is used, the chloroprene concentration of 1 ppmv must be corrected to 3 percent oxygen. - (2) To demonstrate compliance with the emission limits specified in [paragraph (y)(1)](#y-1) of this section for continuous front-end process vents in chloroprene service, owners and operators must meet the requirements specified in [§ 63.510](/cfr/40/63.510.md). - (3) Owners and operators must keep the records specified in paragraphs [(y)(3)(i)](#y-3-i) and [(y)(3)(ii)](#y-3-ii) of this section in addition to those records specified elsewhere in this section. - (i) For process vents, include all uncontrolled, undiluted chloroprene concentration measurements, and the calculations used to determine the total uncontrolled chloroprene mass emission rate for the sum of all vent gas streams. - (ii) The owner or operator must keep records of all periods during which operating values are outside of the applicable operating limits specified in [§ 63.510(b)(4) through (6)](/cfr/40/63.510.md?p=b-4..b-6) when regulated material is being routed to the non-flare control device. The record must specify the operating parameter, the applicable limit, and the highest (for maximum operating limits) or lowest (for minimum operating limits) value recorded during the period. - (4) The Periodic Report must include the records for the periods specified in [paragraph (y)(3)(ii)](#y-3-ii) of this section. Indicate the start date, start time and duration in hours for each period. - (z) For continuous front-end process vents that are in chloroprene service and subject to the requirements of [§ 63.510](/cfr/40/63.510.md), the requirements in [40 CFR 63.113(k)(4)](/cfr/40/63.113.md?p=k-4) do not apply. Instead, in addition to complying with the requirements in paragraphs [40 CFR 63.113(k)(1) through (3)](/cfr/40/63.113.md?p=k-1..k-3), for continuous front-end process vents that are in chloroprene service and subject to the requirements of [§ 63.510](/cfr/40/63.510.md) that are designated as maintenance vents, owners and operators may not release more than 1.0 tons of chloroprene from all maintenance vents combined (i.e., including maintenance vents subject to this [paragraph (z)](#z), [§ 63.487(i)(4)](/cfr/40/63.487.md?p=i-4), or [§ 63.494(a)(7)(iii)](/cfr/40/63.494.md?p=a-7-iii)) per any consecutive 12-month period. The owner or operator must keep monthly records of the quantity in tons of chloroprene released from each maintenance vent and include a description of the method used to estimate this quantity. # §63.486. Batch front-end process vent provisions. - (a) **Batch front-end process vents.** Except as specified in [paragraph (b)](#b) of this section, owners and operators of new and existing affected sources with batch front-end process vents shall comply with the requirements in [§§ 63.487 through 63.492](/cfr/40/63.487..63.492.md). The batch front-end process vent group status shall be determined in accordance with [§ 63.488](/cfr/40/63.488.md). Owners or operators of affected sources with batch front-end process vents classified as Group 1 shall comply with the reference control technology requirements for Group 1 batch front-end process vents in [§ 63.487](/cfr/40/63.487.md), the monitoring requirements in [§ 63.489](/cfr/40/63.489.md), the performance test methods and procedures to determine compliance in [§ 63.490](/cfr/40/63.490.md), the recordkeeping requirements in [§ 63.491](/cfr/40/63.491.md), and the reporting requirements in [§ 63.492](/cfr/40/63.492.md). Owners and operators of all Group 2 batch front-end process vents shall comply with the applicable reference control technology requirements in [§ 63.487](/cfr/40/63.487.md), the applicable recordkeeping requirements in [§ 63.491](/cfr/40/63.491.md), and the applicable reporting requirements in [§ 63.492](/cfr/40/63.492.md). - (b) **Aggregate batch vent streams.** Aggregate batch vent streams, as defined in [§ 63.482](/cfr/40/63.482.md), are subject to the control requirements specified in [§ 63.487(b)](/cfr/40/63.487.md?p=b), as well as the monitoring, testing, recordkeeping, and reporting requirements specified in [§§ 63.489 through 63.492](/cfr/40/63.489..63.492.md) for aggregate batch vent streams. # §63.487. Batch front-end process vents—reference control technology. - (a) **Batch front-end process vents.** Except as specified in [paragraph (j)](#j) of this section, the owner or operator of an affected source with a Group 1 batch front-end process vent, as determined using the procedures in [§ 63.488](/cfr/40/63.488.md), shall comply with the requirements of either paragraph [(a)(1)](#a-1) or [(a)(2)](#a-2) of this section, and [paragraph (a)(3)](#a-3) of this section. Compliance may be based on either organic HAP or TOC. - (1) **For each batch front-end process vent, reduce organic HAP emissions using a flare.** - (i) Except as specified in [paragraph (a)(1)(iii)](#a-1-iii) of this section, the owner or operator of the affected sources shall comply with the requirements of [§ 63.504(c)](/cfr/40/63.504.md?p=c) for the flare. - (ii) Halogenated batch front-end process vents, as defined in [§ 63.482](/cfr/40/63.482.md), shall not be vented to a flare. - (iii) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n), [paragraph (a)(1)(i)](#a-1-i) of this section no longer applies and instead the owner or operator of the affected sources must comply with [§ 63.508](/cfr/40/63.508.md) for the flare. - (2) For each batch front-end process vent, reduce organic HAP emissions for the batch cycle by 90 weight percent using a control device. Owners or operators may achieve compliance with this paragraph through the control of selected batch emission episodes or the control of portions of selected batch emission episodes. Documentation demonstrating how the 90 weight percent emission reduction is achieved is required by [§ 63.490(c)(2)](/cfr/40/63.490.md?p=c-2). - (3) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n), for each batch front-end process vent that contains chlorine, HCl, or any other chlorinated compound, reduce emissions of dioxins and furans (toxic equivalency basis) to a concentration of 0.054 nanograms per standard cubic meter on a dry basis corrected to 3 percent oxygen. - (b) **Aggregate batch vent streams.** Except as specified in [paragraph (j)](#j) of this section the owner or operator of an aggregate batch vent stream that contains one or more Group 1 batch front-end process vents shall comply with the requirements of either paragraph [(b)(1)](#b-1) or [(b)(2)](#b-2) of this section, and [paragraph (b)(3)](#b-3) of this section. Compliance may be based on either organic HAP or TOC. - (1) **For each aggregate batch vent stream, reduce organic HAP emissions using a flare.** - (i) Except as specified in [paragraph (b)(1)(iii)](#b-1-iii) of this section, the owner or operator of the affected source shall comply with the requirements of [§ 63.504(c)](/cfr/40/63.504.md?p=c) for the flare. - (ii) Halogenated aggregate batch vent streams, as defined in [§ 63.482](/cfr/40/63.482.md), shall not be vented to a flare. - (iii) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n), [paragraph (b)(1)(i)](#b-1-i) of this section no longer applies and instead the owner or operator of the affected source must comply with [§ 63.508](/cfr/40/63.508.md) for the flare. - (2) For each aggregate batch vent stream, reduce organic HAP emissions by 90 weight percent or to a concentration of 20 ppmv, on a continuous basis using a control device. For purposes of complying with the 20 ppmv outlet concentration standard, the outlet concentration shall be calculated on a dry basis. When a combustion device is used for purposes of complying with the 20 ppmv outlet concentration standard, the concentration shall be corrected to 3 percent oxygen if supplemental combustion air is used to combust the emissions. If supplemental combustion air is not used, a correction to 3 percent oxygen is not required. - (3) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n), for each aggregate batch vent stream that contains chlorine, HCl, or any other chlorinated compound, reduce emissions of dioxins and furans (toxic equivalency basis) to a concentration of 0.054 nanograms per standard cubic meter on a dry basis corrected to 3 percent oxygen - (c) **Halogenated emissions.** Halogenated Group 1 batch front-end process vents, halogenated aggregate batch vent streams, and halogenated continuous front-end process vents that are combusted as part of complying with paragraph [(a)(2)](#a-2), [(a)(3)](#a-3), [(b)(2)](#b-2), or [(b)(3)](#b-3) of this section, shall be controlled according to either paragraph [(c)(1)](#c-1) or [(c)(2)](#c-2) of this section. - (1) If a combustion device is used to comply with paragraph [(a)(2)](#a-2), [(a)(3)](#a-3), [(b)(2)](#b-2), or [(b)(3)](#b-3) of this section for a halogenated batch front-end process vent or halogenated aggregate batch vent stream, the emissions exiting the combustion device shall be ducted to a halogen reduction device that reduces overall emissions of hydrogen halides and halogens by at least 99 percent before discharge to the atmosphere. - (2) A halogen reduction device may be used to reduce the halogen atom mass emission rate to less than 3,750 kg/yr for batch front-end process vents or aggregate batch vent streams and thus make the batch front-end process vent or aggregate batch vent stream nonhalogenated. The nonhalogenated batch front-end process vent or aggregate batch vent stream shall then comply with the requirements of either paragraph [(a)](#a) or [(b)](#b) of this section, as appropriate. - (d) If a boiler or process heater is used to comply with the percent reduction requirement specified in paragraph [(a)(2)](#a-2) or [(b)(2)](#b-2) of this section, the batch front-end process vent or aggregate batch vent stream shall be introduced into the flame zone of such a device. - (e) **Combination of batch front-end process vents or aggregate batch vent streams with continuous front-end process vents.** If a batch front-end process vent or aggregate batch vent stream is combined with a continuous front-end process vent, the owner or operator shall determine whether the combined vent stream is subject to the provisions of [§§ 63.486 through 63.492](/cfr/40/63.486..63.492.md) according to paragraphs [(e)(1)](#e-1) and [(e)(2)](#e-2) of this section. - (1) A batch front-end process vent or aggregate batch vent stream combined with a continuous front-end process vent stream is not subject to the provisions of [§§ 63.486 through 63.492](/cfr/40/63.486..63.492.md), if the requirements in [paragraph (e)(1)(i)](#e-1-i) and in either paragraph [(e)(1)(ii)](#e-1-ii) or [(e)(1)(iii)](#e-1-iii) are met. - (i) The only emissions to the atmosphere from the batch front-end process vent or aggregate batch vent stream prior to being combined with the continuous front-end process vent are from equipment subject to [§ 63.502](/cfr/40/63.502.md). - (ii) The batch front-end vent stream or aggregate batch vent stream is combined with a Group 1 continuous front-end process vent stream prior to the combined vent stream being routed to a control device. In this [paragraph (e)(1)(ii)](#e-1-ii), the definition of control device as it relates to continuous front-end process vents shall be used. Furthermore, the combined vent stream discussed in this [paragraph (e)(1)(ii)](#e-1-ii) shall be subject to [§ 63.485(o)(1)](/cfr/40/63.485.md?p=o-1). - (iii) Except as specified in [paragraph (e)(1)(iv)](#e-1-iv) of this section, the batch front-end process vent or aggregate batch vent stream is combined with a continuous front-end process vent stream prior to being routed to a recovery device. In this [paragraph (e)(1)(iii)](#e-1-iii), the definition of recovery device as it relates to continuous front-end process vents shall be used. Furthermore, the combined vent stream discussed in this [paragraph (e)(1)(iii)](#e-1-iii) shall be subject to [§ 63.485(o)(2)](/cfr/40/63.485.md?p=o-2). - (iv) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n), [paragraph (e)(1)(iii)](#e-1-iii) of this section no longer applies. - (2) If the batch front-end process vent or aggregate batch vent stream is combined with a Group 2 continuous front-end process vent, the group status of the batch front-end process vent shall be determined prior to its combination with the Group 2 continuous front-end process vent, in accordance with [§ 63.488](/cfr/40/63.488.md), and the combined vent stream shall be subject to the requirements for aggregate batch vent streams in [§§ 63.486 through 63.492](/cfr/40/63.486..63.492.md). - (f) **Group 2 batch front-end process vents with annual emissions greater than or equal to the level specified in § 63.488(d).** Except as specified in [paragraph (j)](#j) of this section, the owner or operator of a Group 2 batch front-end process vent with annual emissions greater than or equal to the level specified in [§ 63.488(d)](/cfr/40/63.488.md?p=d) shall comply with the provisions of paragraph [(f)(1)](#f-1), [(f)(2)](#f-2), or (h) of this section. - (1) The owner or operator shall comply with the requirements in [paragraphs (f)(1)(i) through (f)(1)(iv)](#f-1-i..f-1-iv) of this section. - (i) The owner or operator shall establish a batch mass input limitation that ensures that the Group 2 batch front-end process vent does not become a Group 1 batch front-end process vent. - (ii) Over the course of the affected source's “year,” as reported in the Notification of Compliance Status in accordance with [§ 63.506(e)(5)(ix)](/cfr/40/63.506.md?p=e-5-ix), the owner or operator shall not charge a mass of HAP or material to the batch unit operation that is greater than the level established as the batch mass input limitation. - (iii) The owner or operator of an affected source shall comply with the recordkeeping requirements in [§ 63.491(d)(2)](/cfr/40/63.491.md?p=d-2), and the reporting requirements in § [63.492(a)(3)](/cfr/40/63.492.md?p=a-3), [(b)](/cfr/40/63.492.md?p=a-b) and [(c)](/cfr/40/63.492.md?p=a-c). - (iv) The owner or operator of an affected source shall comply with [§ 63.488(i)](/cfr/40/63.488.md?p=i) when process changes are made. - (2) **Comply with the requirements of this subpart for Group 1 batch front-end process vents.** - (g) **Group 2 batch front-end process vents with annual emissions less than the level specified in § 63.488(d).** Except as specified in [paragraph (j)](#j) of this section, the owner or operator of a Group 2 batch front-end process vent with annual organic HAP emissions less than the level specified in [§ 63.488(d)](/cfr/40/63.488.md?p=d), shall comply with paragraph [(g)(1)](#g-1), [(g)(2)](#g-2), [(g)(3)](#g-3), or [(g)(4)](#g-4) of this section. - (1) The owner or operator of the affected source shall comply with the requirements in [paragraphs (g)(1)(i) through (g)(1)(iv)](#g-1-i..g-1-iv) of this section. - (i) The owner or operator shall establish a batch mass input limitation that ensures emissions do not exceed the appropriate level specified in [§ 63.488(d)](/cfr/40/63.488.md?p=d). - (ii) Over the course of the affected source's “year,” as reported in the Notification of Compliance Status in accordance with [§ 63.506(e)(5)(ix)](/cfr/40/63.506.md?p=e-5-ix), the owner or operator shall not charge a mass of HAP or material to the batch unit operation that is greater than the level established as the batch mass input limitation. - (iii) The owner or operator of the affected source shall comply with the recordkeeping requirements in [§ 63.491(d)(1)](/cfr/40/63.491.md?p=d-1), and the reporting requirements in § [63.492(a)(2)](/cfr/40/63.492.md?p=a-2), [(b)](/cfr/40/63.492.md?p=a-b), and [(c)](/cfr/40/63.492.md?p=a-c). - (iv) The owner or operator of the affected source shall comply with [§ 63.488(i)](/cfr/40/63.488.md?p=i) when process changes are made. - (2) Comply with the requirements of [paragraph (f)(1)](#f-1) of this section; - (3) Comply with the requirements of [paragraph (f)(2)](#f-2) of this section; or - (4) **Comply with the requirements of paragraph (h) of this section.** - (h) Owners or operators of Group 2 batch front-end process vents are not required to establish a batch mass input limitation if the batch front-end process vent is Group 2 at the conditions specified in paragraphs [(h)(1)](#h-1) and [(h)(2)](#h-2) of this section and if the owner or operator complies with the recordkeeping provisions in §§ [63.491(a)(1) through (3)](/cfr/40/63.491.md?p=a-1..a-3), [63.491(a)(9)](/cfr/40/63.491.md?p=a-9), and [63.491(a)(4) through (6)](/cfr/40/63.491.md?p=a-4..a-6) as applicable, and the reporting requirements in § [63.492(a)(5)](/cfr/40/63.492.md?p=a-5) and [(6)](/cfr/40/63.492.md?p=a-6) and [(b)](/cfr/40/63.492.md?p=a-b). - (1) Emissions for the single highest-HAP recipe (considering all products that are produced in the batch unit operation) are used in the group determination; and - (2) The group determination assumes that the batch unit operation is operating at the maximum design capacity of the EPPU for 12 months. - (i) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n), an owner or operator may designate a batch front-end process vent as a maintenance vent if the vent is only used as a result of startup, shutdown, maintenance, or inspection of equipment where equipment is emptied, depressurized, degassed, or placed into service. The owner or operator must comply with the applicable requirements in [paragraphs (i)(1) through (i)(4)](#h-i-1..h-i-4) of this section for each maintenance vent. Any vent designated as a maintenance vent is only subject to the maintenance vent provisions in this paragraph (i) and the associated recordkeeping and reporting requirements in [§ 63.491(h)](/cfr/40/63.491.md?p=h) and [§ 63.492(g)](/cfr/40/63.492.md?p=g), respectively. The owner or operator does not need to designate a maintenance vent as a Group 1 or Group 2 batch front-end process vent nor identify maintenance vents in a Notification of Compliance Status report. - (1) Prior to venting to the atmosphere, remove process liquids from the equipment as much as practical and depressurize the equipment to either: A flare meeting the requirements of [§ 63.508](/cfr/40/63.508.md), as applicable, or using any combination of a non-flare combustion, recovery, and/or recapture device meeting the requirements in [paragraph (a)(2)](#a-2) of this section until one of the following conditions, as applicable, is met. - (i) The concentration of the vapor in the equipment served by the maintenance vent is less than 10 percent of its lower explosive limit (LEL) and has an outlet concentration less than or equal to 20 ppmv hydrogen halide and halogen HAP. - (ii) If there is no ability to measure the concentration of the vapor in the equipment based on the design of the equipment, the pressure in the equipment served by the maintenance vent is reduced to 5 pounds per square inch gauge (psig) or less. Upon opening the maintenance vent, active purging of the equipment cannot be used until the concentration of the vapors in the maintenance vent (or inside the equipment if the maintenance is a hatch or similar type of opening) is less than 10 percent of its LEL. - (iii) The equipment served by the maintenance vent contains less than 50 pounds of total volatile organic compounds (VOC). - (iv) If, after applying best practices to isolate and purge equipment served by a maintenance vent, none of the applicable criterion in [paragraphs (i)(1)(i) through (i)(1)(iii)](#h-i-1-i..h-i-1-iii) of this section can be met prior to installing or removing a blind flange or similar equipment blind, then the pressure in the equipment served by the maintenance vent must be reduced to 2 psig or less before installing or removing the equipment blind. During installation or removal of the equipment blind, active purging of the equipment may be used provided the equipment pressure at the location where purge gas is introduced remains at 2 psig or less. - (2) Except for maintenance vents complying with the alternative in paragraph (i)(1)(iii) of this section, the owner or operator must determine the concentration or, if applicable, equipment pressure using process instrumentation or portable measurement devices and follow procedures for calibration and maintenance according to manufacturer's specifications. - (3) For maintenance vents complying with the alternative in paragraph (i)(1)(iii) of this section, the owner or operator must determine mass of VOC in the equipment served by the maintenance vent based on the equipment size and contents after considering any contents drained or purged from the equipment. Equipment size may be determined from equipment design specifications. Equipment contents may be determined using process knowledge. - (4) In addition to complying with the requirements in [paragraphs (i)(1) through (i)(3)](#h-i-1..h-i-3) of this section, for batch front-end process vents that are in chloroprene service and subject to the requirements of [§ 63.510](/cfr/40/63.510.md) that are designated as maintenance vents, owners and operators may not release more than 1.0 tons of chloroprene from all maintenance vents combined (i.e., including maintenance vents subject to this paragraph (i)(4), [§ 63.485(z)](/cfr/40/63.485.md?p=z), or [§ 63.494(a)(7)(iii)](/cfr/40/63.494.md?p=a-7-iii)) per any consecutive 12-month period. The owner or operator must keep monthly records of the quantity in tons of chloroprene released from each maintenance vent and include a description of the method used to estimate this quantity. - (j) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(o)](/cfr/40/63.481.md?p=o), if the Group 1 or Group 2 batch front-end process vent contains chloroprene such that it is considered to be in chloroprene service, as defined in [§ 63.482](/cfr/40/63.482.md), then the owner or operator must comply with the requirements of [paragraphs (j)(1) through (j)(4)](#j-1..j-4) of this section in addition to all other applicable requirements specified in [§ 63.483](/cfr/40/63.483.md) and elsewhere in this section. - (1) Reduce emissions of chloroprene by venting emissions through a closed vent system to a non-flare control device that reduces chloroprene by greater than or equal to 98 percent by weight, or to a concentration less than 1 ppmv for each process vent or to less than 5 pounds per year for all combined process vents within the process. If a combustion device is used, the chloroprene concentration of 1 ppmv must be corrected to 3 percent oxygen. - (2) To demonstrate compliance with the emission limits specified in [paragraph (j)(1)](#j-1) of this section for batch front-end process vents in chloroprene service, owners and operators must meet the requirements specified in [§ 63.510](/cfr/40/63.510.md). - (3) Owners and operators must keep the records specified in paragraphs [(j)(3)(i)](#j-3-i) and [(j)(3)(ii)](#j-3-ii) of this section in addition to those records specified elsewhere in this section. - (i) For process vents, include all uncontrolled, undiluted chloroprene concentration measurements, and the calculations used to determine the total uncontrolled chloroprene mass emission rate for the sum of all vent gas streams. - (ii) The owner or operator must keep records of all periods during which operating values are outside of the applicable operating limits specified in [§ 63.510(b)(4) through (6)](/cfr/40/63.510.md?p=b-4..b-6) when regulated material is being routed to the non-flare control device. The record must specify the operating parameter, the applicable limit, and the highest (for maximum operating limits) or lowest (for minimum operating limits) value recorded during the period. - (4) The Periodic Report must include the records of periods specified in [paragraph (j)(3)(ii)](#j-3-ii) of this section. Indicate the start date, start time and duration in hours for each period. # §63.488. Methods and procedures for batch front-end process vent group determination. - (a) **General requirements.** Except as provided in [paragraph (a)(3)](#a-3) of this section, the owner or operator of batch front-end process vents at affected sources shall determine the group status of each batch front-end process vent in accordance with the provisions of this section. This determination may be based on either organic HAP or TOC emissions. - (1) The procedures specified in [paragraphs (b) through (g)](#b..g) shall be followed to determine the group status of each batch front-end process vent. This determination shall be made in accordance with either paragraph [(a)(1)(i)](#a-1-i) or [(a)(1)(ii)](#a-1-ii) of this section. - (i) An owner or operator may choose to determine the group status of a batch front-end process vent based on the expected mix of products. For each product, emission characteristics of the single highest-HAP recipe, as defined in [paragraph (a)(1)(iii)](#a-1-iii) of this section, for that product, shall be used in the procedures in [paragraphs (b) through (i)](#b..i) of this section. - (ii) An owner or operator may choose to determine the group status of a batch front-end process vent based on annualized production of the single highest-HAP recipe, as defined in [paragraph (a)(1)(iii)](#a-1-iii) of this section, considering all products produced or processed in the batch unit operation. The annualized production of the highest-HAP recipe shall be based exclusively on the production of the single highest-HAP recipe of all products produced or processed in the batch unit operation for a 12 month period. The production level used may be the actual production rate. It is not necessary to assume a maximum production rate (i.e., 8,760 hours per year at maximum design production). - (iii) The single highest-HAP recipe for a product means the recipe of the product with the highest total mass of HAP charged to the reactor during the production of a single batch of product. - (2) The annual uncontrolled organic HAP or TOC emissions and annual average batch vent flow rate shall be determined at the exit from the batch unit operation. For the purposes of these determinations, the primary condenser operating as a reflux condenser on a reactor or distillation column, the primary condenser recovering monomer, reaction products, by-products, or solvent from a stripper operated in batch mode, and the primary condenser recovering monomer, reaction products, by-products, or solvent from a distillation operation operated in batch mode shall be considered part of the batch unit operation. All other devices that recover or oxidize organic HAP or TOC vapors shall be considered control devices as defined in [§ 63.482](/cfr/40/63.482.md). - (3) The owner or operator of a batch front-end process vent complying with the flare provisions in [§ 63.487(a)(1)](/cfr/40/63.487.md?p=a-1) or [§ 63.487(b)(1)](/cfr/40/63.487.md?p=b-1) or routing the batch front-end process vent to a control device to comply with the requirements in [§ 63.487(a)(2)](/cfr/40/63.487.md?p=a-2) or [§ 63.487(b)(2)](/cfr/40/63.487.md?p=b-2) is not required to perform the batch front-end process vent group determination described in this section, but shall comply with all requirements applicable to Group 1 batch front-end process vents. - (b) **Determination of annual emissions.** The owner or operator shall calculate annual uncontrolled TOC or organic HAP emissions for each batch front-end process vent using the methods described in [paragraphs (b)(1) through (b)(8)](#b-1..b-8) of this section. To estimate emissions from a batch emissions episode, owners or operators may use either the emissions estimation equations in [paragraphs (b)(1) through (b)(4)](#b-1..b-4) of this section, or direct measurement as specified in [paragraph (b)(5)](#b-5) of this section. Engineering assessment may also be used to estimate emissions from a batch emission episode, but only under the conditions described in [paragraph (b)(6)](#b-6) of this section. In using the emissions estimation equations in [paragraphs (b)(1) through (b)(4)](#b-1..b-4) of this section, individual component vapor pressure and molecular weight may be obtained from standard references. Methods to determine individual HAP partial pressures in multicomponent systems are described in [paragraph (b)(9)](#b-9) of this section. Other variables in the emissions estimation equations may be obtained through direct measurement, as defined in [paragraph (b)(5)](#b-5) of this section, through engineering assessment, as defined in [paragraph (b)(6)(ii)](#b-6-ii) of this section, by process knowledge, or by any other appropriate means. Assumptions used in determining these variables must be documented. Once emissions for the batch emission episode have been determined using either the emissions estimation equations, direct measurement, or engineering assessment, emissions from a batch cycle shall be calculated in accordance with [paragraph (b)(7)](#b-7) of this section, and annual emissions from the batch front-end process vent shall be calculated in accordance with [paragraph (b)(8)](#b-8) of this section. - (1) TOC or organic HAP emissions from the purging of an empty vessel shall be calculated using Equation 1. This equation does not take into account evaporation of any residual liquid in the vessel. - (2) TOC or organic HAP emissions from the purging of a filled vessel shall be calculated using Equation 2. - (3) Emissions from vapor displacement due to transfer of material into or out of a vessel shall be calculated using Equation 3. - (4) Emissions caused by the heating of a vessel shall be calculated using the procedures in either paragraph [(b)(4)(i)](#b-4-i), [(b)(4)(ii)](#b-4-ii), or [(b)(4)(iii)](#b-4-iii) of this section, as appropriate. - (i) If the final temperature to which the vessel contents is heated is lower than 50 K below the boiling point of the HAP in the vessel, then emissions shall be calculated using the equations in [paragraphs (b)(4)(i)(A) through (b)(4)(i)(D)](#b-4-i-A..b-4-i-D) of this section. - (A) Emissions caused by heating of a vessel shall be calculated using Equation 4. The assumptions made for this calculation are atmospheric pressure of 760 mm Hg and the displaced gas is always saturated with VOC vapor in equilibrium with the liquid mixture. - (B) **The moles of gas displaced, Δη, is calculated using equation 5.** - (C) The initial and final pressure of the noncondensible gas in the vessel shall be calculated using equation 6. - (D) The weighted average molecular weight of TOC or organic HAP in the displaced gas, MWWAVG, shall be calculated using equation 7: - (ii) If the vessel contents are heated to a temperature greater than 50 K below the boiling point, then emissions from the heating of a vessel shall be calculated as the sum of the emissions calculated in accordance with paragraphs [(b)(4)(ii)(A)](#b-4-ii-A) and [(b)(4)(ii)(B)](#b-4-ii-B) of this section. - (A) For the interval from the initial temperature to the temperature 50 K below the boiling point, emissions shall be calculated using Equation 4, where T2 is the temperature 50 K below the boiling point. - (B) For the interval from the temperature 50 K below the boiling point to the final temperature, emissions shall be calculated as the summation of emissions for each 5 K increment, where the emissions for each increment shall be calculated using Equation 4. (1) If the final temperature of the heatup is at or lower than 5 K below the boiling point, the final temperature for the last increment shall be the final temperature for the heatup, even if the last increment is less than 5 K. (2) If the final temperature of the heatup is higher than 5 K below the boiling point, the final temperature for the last increment shall be the temperature 5 K below the boiling point, even if the last increment is less than 5 K. (3) If the vessel contents are heated to the boiling point and the vessel is not operating with a condenser, the final temperature for the final increment shall be the temperature 5 K below the boiling point, even if the last increment is less than 5 K. - (iii) If the vessel is operating with a condenser, and the vessel contents are heated to the boiling point, the primary condenser is considered part of the process, as described in [§ 63.488(a)(2)](#a-2). Emissions shall be calculated as the sum of Equation 4, which calculates emissions due to heating the vessel contents to the temperature of the gas exiting the condenser, and Equation 3, which calculates emissions due to the displacement of the remaining saturated noncondensible gas in the vessel. The final temperature in Equation 4 shall be set equal to the exit gas temperature of the condenser. Equation 3 shall be used as written below in Equation 3a, using free space volume, and T2 is set equal to the condenser exit gas temperature. - (5) The owner or operator may estimate annual emissions for a batch emission episode by direct measurement. If direct measurement is used, the owner or operator shall either perform a test for the duration of a representative batch emission episode or perform a test during only those periods of the batch emission episode for which the emission rate for the entire episode can be determined or for which the emissions are greater than the average emission rate of the batch emission episode. The owner or operator choosing either of these options shall develop an emission profile for the entire batch emission episode, based on either process knowledge or test data collected, to demonstrate that test periods are representative. Examples of information that could constitute process knowledge include calculations based on material balances and process stoichiometry. Previous test results may be used provided the results are still relevant to the current batch front-end process vent conditions. Performance tests shall follow the procedures specified in [paragraphs (b)(5)(i) through (b)(5)(iii)](#b-5-i..b-5-iii) of this section. The procedures in either paragraph [(b)(5)(iv)](#b-5-iv) or [(b)(5)(v)](#b-5-v) of this section shall be used to calculate the emissions per batch emission episode. - (i) Method 1 or 1A, [40 CFR part 60](/cfr/40/part60.md), appendix A, as appropriate, shall be used for selection of the sampling sites if the flow measuring device is a pitot tube. No traverse is necessary when Method 2A or 2D, [40 CFR part 60](/cfr/40/part60.md), appendix A is used to determine gas stream volumetric flow rate. - (ii) Annual average batch vent flow rate shall be determined as specified in [paragraph (e)](#e) of this section. - (iii) Method 18 or Method 25A of appendices A-6 and A-7 to [40 CFR part 60](/cfr/40/part60.md), respectively, must be used to determine the concentration of TOC or organic HAP, as appropriate. ASTM D6420-18 (incorporated by reference, see [§ 63.14](/cfr/40/63.14.md)) may also be used in lieu of Method 18, if the target compounds are all known and are all listed in [Section 1.1](/cfr/40/1.1.md) of ASTM D6420-18 as measurable; ASTM D6420-18 must not be used for methane and ethane; and ASTM D6420-18 may not be used as a total VOC method. The use of Method 25A must conform with the requirements in paragraphs [(b)(5)(iii)(A)](#b-5-iii-A) and (B) of this section. - (A) The organic HAP used as the calibration gas for Method 25A of appendix A-7 to [40 CFR part 60](/cfr/40/part60.md) must be the single organic HAP representing the largest percent by volume of the emissions. - (iv) If an integrated sample is taken over the entire batch emission episode to determine average batch vent concentration of TOC or total organic HAP, emissions shall be calculated using Equation 8. - (v) If grab samples are taken to determine the average batch vent concentration of TOC or total organic HAP, emissions shall be calculated according to paragraphs [(b)(5)(v)(A)](#b-5-v-A) and [(b)(5)(v)(B)](#b-5-v-B) of this section. - (A) For each measurement point, the emission rate shall be calculated using Equation 9. - (B) The emissions per batch emission episode shall be calculated using Equation 10. - (6) Engineering assessment may be used to estimate emissions from a batch emission episode, if the criteria in [paragraph (b)(6)(i)](#b-6-i) are met. Data or other information used to demonstrate that the criteria in [paragraph (b)(6)(i)](#b-6-i) of this section have been met shall be reported as specified in [paragraph (b)(6)(iii)](#b-6-iii) of this section. [Paragraph (b)(6)(ii)](#b-6-ii) of this section defines engineering assessment, for the purposes of estimating emissions from a batch emissions episode. All data, assumptions, and procedures used in an engineering assessment shall be documented. - (i) If the criteria specified in paragraph [(b)(6)(i)(A)](#b-6-i-A), [(B)](#b-6-i-B), or [(C)](#b-6-i-C) are met for a specific batch emission episode, the owner or operator may use engineering assessment, as described in [paragraph (b)(6)(ii)](#b-6-ii) of this section, to estimate emissions from that batch emission episode, and the owner or operator is not required to use the emissions estimation equations described in [paragraphs (b)(1) through (b)(4)](#b-1..b-4) of this section to estimate emissions from that batch emission episode. - (A) Previous test data, where the measurement of organic HAP or TOC emissions was an outcome of the test, show a greater than 20 percent discrepancy between the test value and the value estimated using the applicable equations in [paragraphs (b)(1) through (b)(4)](#b-1..b-4) of this section. Paragraphs (b)(6)(i)(A)(1) and (2) of this section describe test data that will be acceptable under this [paragraph (b)(6)(i)(A)](#b-6-i-A). (1) Test data for the batch emission episode obtained during production of the product for which the demonstration is being made. (2) Test data obtained for a batch emission episode from another process train, where the test data were obtained during production of the product for which the demonstration is being made. Test data from another process train may be used only if the owner or operator can demonstrate that the data are representative of the batch emission episode for which the demonstration is being made, taking into account the nature, size, operating conditions, production rate, and sequence of process steps (e.g., reaction, distillation, etc.) of the equipment in the other process train. - (B) Previous test data obtained during the production of the product for which the demonstration is being made, for the batch emission episode with the highest organic HAP emissions on a mass basis, show a greater than 20 percent discrepancy between the test value and the value estimated using the applicable equations in [paragraphs (b)(1) through (b)(4)](#b-1..b-4) of this section. If the criteria in this [paragraph (b)(6)(i)(B)](#b-6-i-B) are met, then engineering assessment may be used for all batch emission episodes associated with that batch cycle for that batch unit operation. - (C) The owner or operator has requested approval to use engineering assessment to estimate emissions from a batch emissions episode. The request to use engineering assessment to estimate emissions from a batch emissions episode shall contain sufficient information and data to demonstrate to the Administrator that engineering assessment is an accurate means of estimating emissions for that particular batch emissions episode. The request to use engineering assessment to estimate emissions for a batch emissions episode shall be submitted in the Precompliance Report required under [§ 63.506(e)(3)](/cfr/40/63.506.md?p=e-3). - (ii) **Engineering assessment includes, but is not limited to, the following—** - (A) **Previous test results, provided the test was representative of current operating practices.** - (B) Bench-scale or pilot-scale test data obtained under conditions representative of current process operating conditions. - (C) Flow rate, TOC emission rate, or organic HAP emission rate specified or implied within a permit limit applicable to the batch front-end process vent. - (D) Design analysis based on accepted chemical engineering principles, measurable process parameters, or physical or chemical laws or properties. Examples of analytical methods include, but are not limited to: (1) Use of material balances; (2) Estimation of flow rate based on physical equipment design, such as pump or blower capacities; (3) Estimation of TOC or organic HAP concentrations based on saturation conditions; and (4) Estimation of TOC or organic HAP concentrations based on grab samples of the liquid or vapor. - (iii) Data or other information used to demonstrate that the criteria in [paragraph (b)(6)(i)](#b-6-i) of this section have been met shall be reported as specified in paragraphs [(b)(6)(iii)(A)](#b-6-iii-A) and [(b)(6)(iii)(B)](#b-6-iii-B) of this section. - (A) Data or other information used to demonstrate that the criteria in paragraph [(b)(6)(i)(A)](#b-6-i-A) or [(b)(6)(i)(B)](#b-6-i-B) of this section have been met shall be reported in the Notification of Compliance Status, as required in [§ 63.492(a)(6)](/cfr/40/63.492.md?p=a-6). - (B) The request for approval to use engineering assessment to estimate emissions from a batch emissions episode as allowed under [paragraph (b)(6)(i)(C)](#b-6-i-C) of this section, and sufficient data or other information for demonstrating to the Administrator that engineering assessment is an accurate means of estimating emissions for that particular batch emissions episode shall be submitted with the Precompliance Report, as required in [§ 63.506(e)(3)](/cfr/40/63.506.md?p=e-3). - (7) For each batch front-end process vent, the TOC or organic HAP emissions associated with a single batch cycle shall be calculated using Equation 11. - (8) Annual TOC or organic HAP emissions from a batch front-end process vent shall be calculated using Equation 12. - (9) Individual HAP partial pressures in multicomponent systems shall be determined using the appropriate method specified in [paragraphs (b)(9)(i) through (b)(9)(iii)](#b-9-i..b-9-iii) of this section. - (i) If the components are miscible, use Raoult's law to calculate the partial pressures; - (ii) If the solution is a dilute aqueous mixture, use Henry's law constants to calculate partial pressures; - (iii) If Raoult's law or Henry's law are not appropriate or available, the owner or operator may use any of the options in paragraphs [(b)(9)(iii)(A)](#b-9-iii-A), [(B)](#b-9-iii-B), or [(C)](#b-9-iii-C) of this section. - (A) Experimentally obtained activity coefficients, Henry's law constants, or solubility data; - (B) Models, such as group-contribution models, to predict activity coefficients; or - (C) Assume the components of the system behave independently and use the summation of all vapor pressures from the HAP as the total HAP partial pressure. - (c) [Reserved] - (d) **Minimum emission level exemption.** - (1) Except as specified in [paragraph (d)(2)](#d-2) of this section, a batch front-end process vent with annual emissions of TOC or organic HAP less than 11,800 kg/yr is considered a Group 2 batch front-end process vent and the owner or operator of that batch front-end process vent shall comply with the requirements in § [63.487(f)](/cfr/40/63.487.md?p=f) or [(g)](/cfr/40/63.487.md?p=g). Annual emissions of TOC or organic HAP are determined at the exit of the batch unit operation, as described in [paragraph (a)(2)](#a-2) of this section, and are determined as specified in [paragraph (b)](#b) of this section. The owner or operator of that batch front-end process vent is not required to comply with the provisions in [paragraphs (e) through (g)](#e..g) of this section. - (2) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n), [paragraph (d)(1)](#d-1) of this section no longer applies and instead the collection of all batch front-end process vents with combined total annual emissions of TOC or organic HAP less than 4,536 kg/yr (10,000 lb/yr) are considered Group 2 batch front-end process vents. Annual emissions of TOC or organic HAP are determined at the exit of each batch unit operation, as described in [paragraph (a)(2)](#a-2) of this section, and are determined as specified in [paragraph (b)](#b) of this section. - (e) **Determination of average batch vent flow rate and annual average batch vent flow rate.** Except as specified in [paragraph (e)(4)](#e-4) of this section, the owner or operator shall determine the average batch vent flow rate for each batch emission episode in accordance with one of the procedures provided in [paragraphs (e)(1) through (e)(2)](#e-1..e-2) of this section. The annual average batch vent flow rate for a batch front-end process vent shall be calculated as specified in [paragraph (e)(3)](#e-3) of this section. - (1) Determination of the average batch vent flow rate for a batch emission episode by direct measurement shall be made using the procedures specified in [paragraphs (e)(1)(i) through (e)(1)(iii)](#e-1-i..e-1-iii) of this section. - (i) The vent stream volumetric flow rate (FRi) for a batch emission episode, in scmm at 20 °C, shall be determined using Method 2, 2A, 2C, or 2D of [40 CFR part 60](/cfr/40/part60.md), appendix A, as appropriate. - (ii) The volumetric flow rate of a representative batch emission episode shall be measured every 15 minutes. - (iii) The average batch vent flow rate for a batch emission episode shall be calculated using Equation 13. - (2) The average batch vent flow rate for a batch emission episode may be determined by engineering assessment, as defined in [paragraph (b)(6)(i)](#b-6-i) of this section. All data, assumptions, and procedures used shall be documented. - (3) The annual average batch vent flow rate for a batch front-end process vent shall be calculated using Equation 14. - (4) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n), [paragraph (e)](#e) of this section no longer applies. - (f) **Determination of cutoff flow rate.** - (1) Except as specified in [paragraph (f)(2)](#f-2) of this section, for each batch front-end process vent, the owner or operator shall calculate the cutoff flow rate using Equation 15. - (2) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n), [paragraph (f)](#f) of this section no longer applies. - (g) **Group 1/Group 2 status determination.** Except as specified in [paragraph (g)(3)](#g-3) of this section, the owner or operator shall compare the cutoff flow rate, calculated in accordance with [paragraph (f)](#f) of this section, with the annual average batch vent flow rate, determined in accordance with [paragraph (e)(3)](#e-3) of this section. The group determination status for each batch front-end process vent shall be made using the criteria specified in paragraphs [(g)(1)](#g-1) and [(g)(2)](#g-2) of this section. - (1) If the cutoff flow rate is greater than or equal to the annual average batch vent flow rate of the stream, the batch front-end process vent is classified as a Group 1 batch front-end process vent. - (2) If the cutoff flow rate is less than the annual average batch vent flow rate of the stream, the batch front-end process vent is classified as a Group 2 batch front-end process vent. - (3) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n), [paragraph (g)](#g) of this section no longer applies. - (h) **Determination of halogenation status.** To determine whether a batch front-end process vent or an aggregate batch vent stream is halogenated, the annual mass emission rate of halogen atoms contained in organic compounds shall be calculated using the procedures specified in [paragraphs (h)(1) through (h)(3)](#h-1..h-3) of this section. - (1) The concentration of each organic compound containing halogen atoms (ppmv, by compound) for each batch emission episode shall be determined after the last recovery device (if any recovery devices are present), based on any one of the following procedures: - (i) Process knowledge that no halogens or hydrogen halides are present in the process may be used to demonstrate that a batch emission episode is nonhalogenated. Halogens or hydrogen halides that are unintentionally introduced into the process shall not be considered in making a finding that a batch emission episode is nonhalogenated. - (ii) **Engineering assessment as discussed in paragraph (b)(6)(i) of this section.** - (iii) Average concentration of organic compounds containing halogens and hydrogen halides as measured by Method 26 or 26A of [40 CFR part 60](/cfr/40/part60.md), appendix A. - (iv) Any other method or data that has been validated according to the applicable procedures in Method 301, [40 CFR part 63](/cfr/40/part63.md), appendix A. - (2) The annual mass emissions of halogen atoms for a batch front-end process vent shall be calculated using Equation 16. - (3) The annual mass emissions of halogen atoms for an aggregate batch vent stream shall be the sum of the annual mass emissions of halogen atoms for all batch front-end process vents included in the aggregate batch vent stream. - (i) **Process changes affecting Group 2 batch front-end process vents.** Whenever process changes, as described in paragraph (i)(1) of this section, are made that affect one or more Group 2 batch front-end process vents and that could reasonably be expected to change one or more Group 2 batch front-end process vents to Group 1 batch front-end process vents or that could reasonably be expected to reduce the batch mass input limitation for one or more Group 2 batch front-end process vents, the owner or operator of the affected source shall comply with paragraphs (i)(2) and (i)(3) of this section. - (1) Examples of process changes include the changes listed in paragraphs (i)(1)(i), (i)(1)(ii), and (i)(1)(iii) of this section. - (i) For all batch front-end process vents, examples of process changes include, but are not limited to, changes in feedstock type or catalyst type; or whenever there is replacement, removal, or modification of recovery equipment considered part of the batch unit operation as specified in [paragraph (a)(2)](#a-2) of this section; or increases in production capacity or production rate. For purposes of this paragraph, process changes do not include: Process upsets; unintentional, temporary process changes; and changes that are within the margin of variation on which the original group determination was based. - (ii) For Group 2 batch front-end process vents where the group determination and batch mass input limitation are based on the expected mix of products, the situations described in paragraphs (i)(1)(ii)(A) and (B) of this section shall be considered to be process changes. - (A) The production of combinations of products not considered in establishing the batch mass input limitation. - (B) The production of a recipe of a product with a total mass of HAP charged to the reactor during the production of a single batch of product that is higher than the total mass of HAP for the recipe used as the single highest-HAP recipe for that product in the batch mass input limitation determination. - (iii) For Group 2 batch front-end process vents where the group determination and batch mass input limitation are based on the single highest-HAP recipe (considering all products produced or processed in the batch unit operation), the production of a recipe having a total mass of HAP charged to the reactor (during the production of a single batch of product) that is higher than the total mass of HAP for the highest-HAP recipe used in the batch mass input limitation determination shall be considered to be a process change. - (2) For each batch front-end process vent affected by a process change, the owner or operator shall redetermine the group status by repeating the procedures specified in [paragraphs (b) through (g)](#b..g) of this section, as applicable. Alternatively, engineering assessment, as described in [paragraph (b)(6)(i)](#b-6-i) of this section, may be used to determine the effects of the process change. - (3) Based on the results of paragraph (i)(2) of this section, owners or operators of affected sources shall comply with either paragraph (i)(3)(i), (ii), or (iii) of this section. - (i) If the group redetermination described in paragraph (i)(2) of this section indicates that a Group 2 batch front-end process vent has become a Group 1 batch front-end process vent as a result of the process change, the owner or operator of the affected source shall submit a report as specified in [§ 63.492(b)](/cfr/40/63.492.md?p=b) and shall comply with the Group 1 provisions in [§§ 63.487 through 63.492](/cfr/40/63.487..63.492.md) in accordance with § [63.480(i)(2)(ii)](/cfr/40/63.480.md?p=i-2-ii) or [(i)(2)(iii)](/cfr/40/63.480.md?p=i-2-iii), as applicable. - (ii) If the redetermination described in paragraph (i)(2) of this section indicates that a Group 2 batch front-end process vent with annual emissions less than the applicable level specified in [paragraph (d)](#d) of this section, and that is in compliance with [§ 63.487(g)](/cfr/40/63.487.md?p=g), now has annual emissions greater than or equal to the applicable level specified by [paragraph (d)](#d) of this section but remains a Group 2 batch front-end process vent, the owner or operator of the affected source shall comply with the provisions in [paragraphs (i)(3)(ii)(A) through (C)](#h-i-3-ii-A..h-i-3-ii-C) of this section. - (A) Redetermine the batch mass input limitation; - (B) Submit a report as specified in [§ 63.492(c)](/cfr/40/63.492.md?p=c); and - (C) Comply with [§ 63.487(f)](/cfr/40/63.487.md?p=f), beginning with the year following the submittal of the report submitted according to paragraph (i)(3)(ii)(B) of this section. - (iii) If the group redetermination described in paragraph (i)(2) of this section indicates no change in group status or no change in the relation of annual emissions to the levels specified in [paragraph (d)](#d) of this section, the owner or operator of the affected source shall comply with paragraphs (i)(3)(iii)(A) and (i)(3)(iii)(B) of this section. - (A) The owner or operator shall redetermine the batch mass input limitation; and - (B) The owner or operator shall submit the new batch mass input limitation in accordance with [§ 63.492(c)](/cfr/40/63.492.md?p=c). # §63.489. Batch front-end process vents—monitoring equipment. - (a) **General requirements.** Each owner or operator of a batch front-end process vent or aggregate batch vent stream that uses a control device to comply with the requirements in § [63.487(a)(2)](/cfr/40/63.487.md?p=a-2) or [(3)](/cfr/40/63.487.md?p=a-3) or § [63.487(b)(2)](/cfr/40/63.487.md?p=b-2) or [(3)](/cfr/40/63.487.md?p=b-3) shall install the monitoring equipment specified in [paragraph (b)](#b) of this section. All monitoring equipment shall be installed, calibrated, maintained, and operated according to the manufacturer's specifications or other written procedures that provide adequate assurance that the equipment would reasonably be expected to monitor accurately. - (1) This monitoring equipment shall be in operation at all times when batch emission episodes, or portions thereof, that the owner or operator has selected to control are vented to the control device, or at all times when an aggregate batch vent stream is vented to the control device. - (2) Except as otherwise provided in this subpart, the owner or operator shall operate control devices such that the daily average of monitored parameters, established as specified in [paragraph (e)](#e) of this section, remains above the minimum level or below the maximum level, as appropriate. - (b) **Batch front-end process vent and aggregate batch vent stream monitoring equipment.** The monitoring equipment specified in [paragraphs (b)(1) through (b)(11)](#b-1..b-11) of this section shall be installed as specified in [paragraph (a)](#a) of this section. The parameters to be monitored are specified in Table 6 of this subpart. - (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, the 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 [paragraph (b)(9)](#b-9) of this section, 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 is required. - (3) Where a boiler or process heater of less than 44 megawatts design heat input capacity is used, a temperature monitoring device in the firebox equipped with a continuous recorder is required. Any boiler or process heater in which all batch front-end process vents or aggregate batch vent streams are introduced with the primary fuel or are used as the primary fuel is exempt from this requirement. - (4) Where a scrubber is used with an incinerator, boiler, or process heater in concert with the combustion of halogenated batch front-end process vents or halogenated aggregate batch vent streams, the following monitoring equipment is required for the scrubber: - (i) A pH monitoring device equipped with a continuous recorder to monitor the pH of the scrubber effluent; and - (ii) A flow measurement device equipped with a continuous recorder shall be located at the scrubber influent for liquid flow. Gas stream flow shall be determined using one of the procedures specified in [paragraphs (b)(4)(ii)(A) through (b)(4)(ii)(C)](#b-4-ii-A..b-4-ii-C) of this section. - (A) The owner or operator may determine gas stream flow using the design blower capacity, with appropriate adjustments for pressure drop. - (B) If the scrubber is subject to regulations in 40 CFR parts [264](/cfr/40/part264.md) through [266](/cfr/40/part266.md) that have required a determination of the liquid to gas (L/G) ratio prior to the applicable compliance date for this subpart, the owner or operator may determine gas stream flow by the method that had been utilized to comply with those regulations. 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 stream flow determination plan that documents an appropriate method which will be used to determine the gas stream flow. The plan shall require determination of gas stream flow by a method which will at least provide a value for either a representative or the highest gas stream flow anticipated in the scrubber during representative operating conditions. 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 stream flow, and a description of the records that will be maintained to document the determination of gas stream flow. The owner or operator shall maintain the plan as specified in [§ 63.506(a)](/cfr/40/63.506.md?p=a). - (5) Where an absorber is used, a scrubbing liquid temperature monitoring device and a specific gravity monitoring device are required, each equipped with a continuous recorder. - (6) Where a condenser is used, a condenser exit temperature (product side) monitoring device equipped with a continuous recorder is required. - (7) Except as specified in [paragraph (b)(10)](#b-10) of this section, where a carbon adsorber is used, an integrating regeneration steam flow, nitrogen flow, or pressure monitoring device having an accuracy of ±10 percent of the flow rate, level, or pressure, or better, capable of recording the total regeneration steam flow or nitrogen flow, or pressure (gauge or absolute) 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 are required. - (8) As an alternate to [paragraphs (b)(5) through (b)(7)](#b-5..b-7) of this section, the owner or operator may install an organic monitoring device equipped with a continuous recorder. - (9) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n), [paragraph (b)(2)](#b-2) of this section no longer applies and instead the owner or operator of the affected source must comply with [§ 63.508](/cfr/40/63.508.md) for the flare. - (10) Beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n), 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 (b)(10)(i) through (b)(10)(iii)](#b-10-i..b-10-iii) of this section. - (i) Conduct an initial performance test or design evaluation of the adsorber and establish the breakthrough limit and adsorber bed life. - (ii) 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 (b)(10)(iii)(B)](#b-10-iii-B) 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 [40 CFR part 60](/cfr/40/part60.md), appendix A-7 using methane, propane, isobutylene, or the primary HAP being controlled as the calibration gas or Method 25A of [40 CFR part 60](/cfr/40/part60.md), appendix A-7 using methane, propane, or the primary HAP being controlled as the calibration gas. - (iii) Comply with [paragraph (b)(10)(iii)(A)](#b-10-iii-A) of this section, and comply with the monitoring frequency according to [paragraph (b)(10)(iii)(B)](#b-10-iii-B) of this section. - (A) The first adsorber in series must be replaced immediately when breakthrough, as defined in [§ 63.482](/cfr/40/63.482.md), 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. - (B) Based on the adsorber bed life established according to [paragraph (b)(10)(i)](#b-10-i) 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. - (11) 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.** - (c) **Alternative monitoring parameters.** An owner or operator of a batch front-end process vent or aggregate batch vent stream may request approval to monitor parameters other than those required by [paragraph (b)](#b) of this section. The request shall be submitted according to the procedures specified in [§ 63.492(e)](/cfr/40/63.492.md?p=e) and [§ 63.506(f)](/cfr/40/63.506.md?p=f). Approval shall be requested if the owner or operator: - (1) Uses a control device other than those included in [paragraph (b)](#b) of this section; or - (2) Uses one of the control devices included in [paragraph (b)](#b) of this section, but seeks to monitor a parameter other than those specified in Table 6 of this subpart and [paragraph (b)](#b) of this section. - (d) **Monitoring of bypass lines.** The owner or operator of a batch front-end process vent or aggregate batch vent stream using a vent system that contains bypass lines that could divert emissions away from a control device used to comply with [§ 63.487(a)](/cfr/40/63.487.md?p=a) or [§ 63.487(b)](/cfr/40/63.487.md?p=b) shall comply with either paragraph [(d)(1)](#d-1) or [(d)(2)](#d-2), and [(d)(3)](#d-3) of this section. Except as specified in [paragraph (d)(3)](#d-3) 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)](#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 [§ 63.491(e)(3)](/cfr/40/63.491.md?p=e-3). The flow indicator shall be installed at the entrance to any bypass line that could divert emissions away from the control device and to the atmosphere; or - (2) Secure the bypass line damper or 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 damper or valve is maintained in the non-diverting position and emissions are not diverted through the bypass line. Records shall be generated as specified in [§ 63.491(e)(4)](/cfr/40/63.491.md?p=e-4). - (3) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n): - (i) The use of a bypass line at any time on a closed vent system to divert emissions (subject to the emission standards in [§ 63.487](/cfr/40/63.487.md)) 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 paragraph [(d)(3)(ii)(A)](#d-3-ii-A) and [(d)(3)(ii)(B)](#d-3-ii-B) of this section apply. - (A) Except for pressure relief devices subject to [§ 63.165(e)(4)](/cfr/40/63.165.md?p=e-4) of [subpart H](/cfr/40/subpartH.md) of this part, equipment such as low leg drains and equipment subject to the requirements of [subpart H](/cfr/40/subpartH.md) of this part are not subject to this [paragraph (d)](#d). - (B) Open-ended valves or lines that use a cap, blind flange, plug, or second valve and follow the requirements specified in 40 CFR [60.482-6(a)(2)](/cfr/40/60.482-6.md?p=a-2), [(b)](/cfr/40/60.482-6.md?p=a-b), and [(c)](/cfr/40/60.482-6.md?p=a-c) or follow requirements codified in another regulation that are the same as 40 CFR [60.482-6(a)(2)](/cfr/40/60.482-6.md?p=a-2), [(b)](/cfr/40/60.482-6.md?p=a-b), and [(c)](/cfr/40/60.482-6.md?p=a-c) are not subject to this [paragraph (d)](#d) of this section. - (e) **Establishment of parameter monitoring levels.** Parameter monitoring levels for batch front-end process vents and aggregate batch vent streams shall be established as specified in [paragraphs (e)(1) through (e)(3)](#e-1..e-3) of this section. - (1) For each parameter monitored under paragraph [(b)](#b) or [(c)](#c) of this section, the owner or operator shall establish a level, defined as either a maximum or minimum operating parameter as denoted in Table 7 of this subpart, that indicates proper operation of the control device. The level shall be established in accordance with the procedures specified in [§ 63.505](/cfr/40/63.505.md). The level 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 a performance test under [§ 63.490](/cfr/40/63.490.md), provided that the prior performance test meets the conditions of [§ 63.490(b)(3)](/cfr/40/63.490.md?p=b-3). - (i) For batch front-end process vents using a control device to comply with [§ 63.487(a)(2)](/cfr/40/63.487.md?p=a-2), the established level shall reflect the control efficiency established as part of the most recent compliance demonstration specified in [§ 63.490(c)(2)](/cfr/40/63.490.md?p=c-2). - (ii) For aggregate batch vent streams using a control device to comply with [§ 63.487(b)(2)](/cfr/40/63.487.md?p=b-2), the established level shall reflect the emission reduction requirement of either 90 percent or 20 ppmv specified in [§ 63.487(b)(2)](/cfr/40/63.487.md?p=b-2). - (iii) For batch front-end process vents using a control device to comply with [§ 63.487(a)(3)](/cfr/40/63.487.md?p=a-3) and aggregate batch vent streams using a control device to comply with [§ 63.487 (b)(3)](/cfr/40/63.487.md?p=b-3), the established level shall reflect the level of control established as part of the most recent compliance demonstration specified in [§ 63.490(g)](/cfr/40/63.490.md?p=g). - (2) The established level, along with supporting documentation, shall be submitted in the Notification of Compliance Status or the operating permit application as required in [§ 63.506(e)(5)](/cfr/40/63.506.md?p=e-5) or [§ 63.506(e)(8)](/cfr/40/63.506.md?p=e-8), respectively. - (3) The operating day shall be defined as part of establishing the parameter monitoring level and shall be submitted with the information in [paragraph (e)(2)](#e-2) of this section. The definition of operating day shall specify the time(s) at which an operating day begins and ends. The operating day shall not exceed 24 hours. # §63.490. Batch front-end process vents—performance test methods and procedures to determine compliance. - (a) **Use of a flare.** - (1) Except as specified in [paragraph (a)(2)](#a-2) of this section, when a flare is used to comply with § [63.487(a)(1)](/cfr/40/63.487.md?p=a-1) or [(b)(1)](/cfr/40/63.487.md?p=b-1), the owner or operator of an affected source shall comply with [§ 63.504(c)](/cfr/40/63.504.md?p=c). - (2) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n), [paragraph (a)(1)](#a-1) of this section no longer applies and instead the owner or operator of the affected source must comply with [§ 63.508](/cfr/40/63.508.md) for the flare. - (b) **Exceptions to performance tests.** An owner or operator is not required to conduct a performance test when a control device specified in [paragraphs (b)(1) through (b)(5)](#b-1..b-5) of this section is used to comply with [§ 63.487(a)(2)](/cfr/40/63.487.md?p=a-2). - (1) **A boiler or process heater with a design heat input capacity of 44 megawatts or greater.** - (2) A boiler or process heater where the vent stream is introduced with the primary fuel or is used as the primary fuel. - (3) A control device for which a performance test was conducted for determining compliance with a regulation promulgated by the EPA and the test was conducted using the same Methods specified in this section and either no deliberate 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. - (4) **A boiler or process heater burning hazardous waste for which the owner or operator—** - (i) Has been issued a final permit under [40 CFR part 270](/cfr/40/part270.md) and complies with the requirements of [40 CFR part 266](/cfr/40/part266.md), [subpart H](/cfr/40/subpartH.md); or - (ii) **Has certified compliance with the interim status requirements of 40 CFR part 266, subpart H.** - (5) A hazardous waste incinerator for which the owner or operator has been issued a final permit under [40 CFR part 270](/cfr/40/part270.md) and complies with the requirements of [40 CFR part 264](/cfr/40/part264.md), [subpart O](/cfr/40/subpartO.md), or has certified compliance with the interim status requirements of [40 CFR part 265](/cfr/40/part265.md), subpart O. - (c) **Batch front-end process vent testing and procedures for compliance with § 63.487(a)(2).** Except as provided in paragraph [(a)](#a) or [(b)](#b) of this section, an owner or operator using a control device to comply with [§ 63.487(a)(2)](/cfr/40/63.487.md?p=a-2) shall conduct a performance test using the procedures specified in [paragraph (c)(1)](#c-1) of this section in order to determine the control efficiency of the control device. An owner or operator shall determine the percent reduction for the batch cycle using the control efficiency of the control device as specified in [paragraphs (c)(2)(i) through (c)(2)(iii)](#c-2-i..c-2-iii) of this section and the procedures specified in [paragraph (c)(2)](#c-2) of this section. Compliance may be based on either total organic HAP or TOC. For purposes of this [paragraph (c)](#c), the term “batch emission episode” shall have the meaning “period of the batch emission episode selected for control,” which may be the entire batch emission episode or may only be a portion of the batch emission episode. - (1) Performance tests shall be conducted as specified in [paragraphs (c)(1)(i) through (c)(1)(v)](#c-1-i..c-1-v) of this section. - (i) Except as specified in [paragraph (c)(1)(i)(A)](#c-1-i-A) of this section, a test shall be performed for the entire period of each batch emission episode in the batch cycle that the owner or operator selects to control as part of achieving the required 90 percent emission reduction for the batch cycle specified in [§ 63.487(a)(2)](/cfr/40/63.487.md?p=a-2). Only one test is required for each batch emission episode selected by the owner or operator for control. The owner or operator shall follow the procedures listed in [paragraphs (c)(1)(i)(B) through (c)(1)(i)(D)](#c-1-i-B..c-1-i-D) of this section. - (A) Alternatively, an owner or operator may choose to test only those periods of the batch emission episode during which the emission rate for the entire episode can be determined or during which the emissions are greater than the average emission rate of the batch emission episode. The owner or operator choosing either of these options shall develop an emission profile for the entire batch emission episode, based on either process knowledge or test data collected, to demonstrate that test periods are representative. Examples of information that could constitute process knowledge include calculations based on material balances and process stoichiometry. Previous test results may be used, provided the results are still relevant to the current batch front-end process vent conditions. - (B) Method 1 or 1A, [40 CFR part 60](/cfr/40/part60.md), appendix A, as appropriate, shall be used for selection of the sampling sites if the flow measuring device is a pitot tube, except that references to particulate matter in Method 1A do not apply for the purposes of this subpart. No traverse is necessary when Method 2A or 2D, [40 CFR part 60](/cfr/40/part60.md), appendix A is used to determine gas stream volumetric flow rate. Inlet sampling sites shall be located as specified in paragraphs (c)(1)(i)(B)(1) and (c)(1)(i)(B)(2) of this section. Outlet sampling sites shall be located at the outlet of the final control device prior to release to the atmosphere. (1) The control device inlet sampling site shall be located at the exit from the batch unit operation before any control device. [Section 63.488(a)(2)](/cfr/40/63.488.md?p=a-2) describes those recovery devices considered part of the unit operation. Inlet sampling sites would be after these specified recovery devices. (2) If a batch process vent is introduced with the combustion air or as a secondary fuel into a boiler or process heater with a design capacity less than 44 megawatts, selection of the location of the inlet sampling sites shall ensure the measurement of total organic HAP or TOC (minus methane and ethane) concentrations in all batch front-end process vents and primary and secondary fuels introduced into the boiler or process heater. - (C) Gas stream volumetric flow rate and/or average batch vent flow rate shall be determined as specified in [§ 63.488(e)](/cfr/40/63.488.md?p=e). - (D) Method 18 or Method 25A of appendices A-6 and A-7 to [40 CFR part 60](/cfr/40/part60.md), respectively must be used to determine the concentration of organic HAP or TOC, as appropriate. ASTM D6420-18 (incorporated by reference, see [§ 63.14](/cfr/40/63.14.md)) may also be used in lieu of Method 18, if the target compounds are all known and are all listed in [Section 1.1](/cfr/40/1.1.md) of ASTM D6420-18 as measurable; ASTM D6420-18 must not be used for methane and ethane; and ASTM D6420-18 may not be used as a total VOC method. Alternatively, any other method or data that has been validated according to the applicable procedures in Method 301 of appendix A to this part may be used. The use of Method 25A must conform with the requirements in paragraphs (c)(1)(i)(D)(1) and (2) of this section. (1) The organic HAP used as the calibration gas for Method 25A appendix A-7 to [40 CFR part 60](/cfr/40/part60.md) must be the single organic HAP representing the largest percent by volume of the emissions. (2) The use of Method 25A appendix A-7 to [40 CFR part 60](/cfr/40/part60.md) is acceptable if the response from the high-level calibration gas is at least 20 times the standard deviation of the response from the zero calibration gas when the instrument is zeroed on the most sensitive scale. - (ii) If an integrated sample is taken over the entire batch emission episode to determine the average batch vent concentration of TOC or total organic HAP, emissions per batch emission episode shall be calculated using Equations 18 and 19. - (iii) If grab samples are taken to determine the average batch vent concentration of TOC or total organic HAP, emissions shall be calculated according to paragraphs [(c)(1)(iii)(A)](#c-1-iii-A) and [(c)(1)(iii)(B)](#c-1-iii-B) of this section. - (A) For each measurement point, the emission rates shall be calculated using Equations 20 and 21. - (B) The emissions per batch emission episode shall be calculated using Equations 22 and 23. - (iv) The control efficiency for the control device shall be calculated using Equation 24. - (v) If the batch front-end process vent entering a boiler or process heater with a design capacity less than 44 megawatts is introduced with the combustion air or as a secondary fuel, the weight-percent reduction of total organic HAP or TOC across the device shall be determined by comparing the TOC or total organic HAP in all combusted batch front-end process vents and primary and secondary fuels with the TOC or total organic HAP, respectively, exiting the combustion device. - (2) The percent reduction for the batch cycle shall be determined using Equation 25 and the control device efficiencies specified in [paragraphs (c)(2)(i) through (c)(2)(iii)](#c-2-i..c-2-iii) of this section. All information used to calculate the batch cycle percent reduction, including a definition of the batch cycle identifying all batch emission episodes, shall be recorded as specified in [§ 63.491(b)(2)](/cfr/40/63.491.md?p=b-2). This information shall include identification of those batch emission episodes, or portions thereof, selected for control. - (i) If a performance test is required by [paragraph (c)](#c) of this section, the control efficiency of the control device shall be as determined in [paragraph (c)(1)(iv)](#c-1-iv) of this section. - (ii) If a performance test is not required by [paragraph (c)](#c) of this section for a combustion control device, as specified in [paragraph (b)](#b) of this section, the control efficiency of the control device shall be 98 percent. The control efficiency for a flare shall be 98 percent. - (iii) If a performance test is not required by [paragraph (c)](#c) of this section for a noncombustion control device, the control efficiency shall be determined by the owner or operator based on engineering assessment. - (d) **Batch process vent and aggregate batch vent stream testing for compliance with § 63.487(c) [halogenated emission streams].** An owner or operator controlling halogenated emissions in compliance with [§ 63.487(c)](/cfr/40/63.487.md?p=c) shall conduct a performance test to determine compliance with the control efficiency specified in [§ 63.487(c)(1)](/cfr/40/63.487.md?p=c-1) or the emission limit specified in [§ 63.487(c)(2)](/cfr/40/63.487.md?p=c-2) for hydrogen halides and halogens. - (1) Sampling sites shall be located at the inlet and outlet of the scrubber or other halogen reduction device used to reduce halogen emissions in complying with [§ 63.487(c)(1)](/cfr/40/63.487.md?p=c-1) or at the outlet of the halogen reduction device used to reduce halogen emissions in complying with [§ 63.487(c)(2)](/cfr/40/63.487.md?p=c-2). - (2) The mass emissions of each hydrogen halide and halogen compound for the batch cycle or aggregate batch vent stream shall be calculated from the measured concentrations and the gas stream flow rate(s) determined by the procedures specified in paragraphs [(d)(2)(i)](#d-2-i) and [(d)(2)(ii)](#d-2-ii) of this section, except as specified in [paragraph (d)(5)](#d-5) of this section. - (i) Method 26 or Method 26A of [40 CFR part 60](/cfr/40/part60.md), appendix A, shall be used to determine the concentration, in Mg per dry scm, of total hydrogen halides and halogens present in the emissions stream. - (ii) Gas stream volumetric flow rate and/or average batch vent flow rate shall be determined as specified in [§ 63.488(e)](/cfr/40/63.488.md?p=e). - (3) To determine compliance with the percent reduction specified in [§ 63.487(c)(1)](/cfr/40/63.487.md?p=c-1), the mass emissions for any hydrogen halides and halogens present at the inlet of the scrubber or other halogen reduction device shall be summed together. The mass emissions of any hydrogen halides or halogens present at the outlet of the scrubber or other halogen reduction device shall be summed together. Percent reduction shall be determined by subtracting the outlet mass emissions from the inlet mass emissions and then dividing the result by the inlet mass emissions and multiplying by 100. - (4) To determine compliance with the emission limit specified in [§ 63.487(c)(2)](/cfr/40/63.487.md?p=c-2), the annual mass emissions for any hydrogen halides and halogens present at the outlet of the halogen reduction device and prior to any combustion device shall be summed together and compared to the emission limit specified in [§ 63.487(c)(2)](/cfr/40/63.487.md?p=c-2). - (5) The owner or operator may use any other method to demonstrate compliance if the method or data has been validated according to the applicable procedures of Method 301, [40 CFR part 63](/cfr/40/part63.md), appendix A. - (e) **Aggregate batch vent stream testing for compliance with § 63.487(b)(2).** Except as specified in [paragraphs (e)(1) through (e)(3)](#e-1..e-3) of this section, owners or operators of aggregate batch vent streams complying with [§ 63.487(b)(2)](/cfr/40/63.487.md?p=b-2) shall conduct a performance test using the performance testing procedures for continuous front-end process vents in [§ 63.116(c)](/cfr/40/63.116.md?p=c). - (1) For the purposes of this subpart, when the provisions of [§ 63.116(c)](/cfr/40/63.116.md?p=c) specify that Method 18 of appendix A-6 to [40 CFR part 60](/cfr/40/part60.md) must be used, Method 18 or Method 25A of appendix A-7 to [40 CFR part 60](/cfr/40/part60.md) may be used. ASTM D6420-18 (incorporated by reference, see [§ 63.14](/cfr/40/63.14.md)) may also be used in lieu of Method 18, if the target compounds are all known and are all listed in [Section 1.1](/cfr/40/1.1.md) of ASTM D6420-18 as measurable; ASTM D6420-18 must not be used for methane and ethane; and ASTM D6420-18 may not be used as a total VOC method. The use of Method 25A of appendix A-7 to [40 CFR part 60](/cfr/40/part60.md) must conform with the requirements in paragraphs [(e)(1)(i)](#e-1-i) and [(ii)](#e-1-ii) of this section. - (i) The organic HAP used as the calibration gas for Method 25A of appendix A-7 to [40 CFR part 60](/cfr/40/part60.md) must be the single organic HAP representing the largest percent by volume of the emissions. - (ii) The use of Method 25A of appendix A-7 to [40 CFR part 60](/cfr/40/part60.md) is acceptable if the response from the high-level calibration gas is at least 20 times the standard deviation of the response from the zero calibration gas when the instrument is zeroed on the most sensitive scale. - (2) When [§ 63.116(c)(4)](/cfr/40/63.116.md?p=c-4) refers to complying with an emission reduction of 98 percent, for the purposes of this subpart, the 90 percent reduction requirement specified in [§ 63.487(b)(2)](/cfr/40/63.487.md?p=b-2) shall apply. - (3) When a combustion device is used to comply with the 20 parts per million by volume outlet concentration standard specified in [§ 63.487(b)(2)](/cfr/40/63.487.md?p=b-2), the correction to 3 percent oxygen specified in the performance testing procedures of § [63.116(c)(3)](/cfr/40/63.116.md?p=c-3) and [(c)(3)(iii)](/cfr/40/63.116.md?p=c-3-iii) is only required when supplemental combustion air is used to combust the emissions, for the purposes of this subpart. - (f) **Batch mass input limitation.** The batch mass input limitation required by [§ 63.487(g)(1)](/cfr/40/63.487.md?p=g-1) shall be determined by the owner or operator such that annual emissions for the batch front-end process vent remain less than the level specified in [§ 63.488(d)](/cfr/40/63.488.md?p=d). The batch mass input limitation required by [§ 63.487(f)(1)](/cfr/40/63.487.md?p=f-1) shall be determined by the owner or operator such that annual emissions remain at a level that ensures that the batch front-end process vent remains a Group 2 batch front-end process vent, given the actual annual flow rate for that batch front-end process vent determined according to [§ 63.488(e)(3)](/cfr/40/63.488.md?p=e-3). The batch mass input limitation shall be determined using the same basis, as described in [§ 63.488(a)(1)](/cfr/40/63.488.md?p=a-1), used to make the group determination (i.e., expected mix of products or highest-HAP recipe). The establishment of the batch mass input limitation is not dependent upon any past production or activity level. - (1) If the expected mix of products serves as the basis for the batch mass input limitation, the batch mass input limitation shall be determined based on any foreseeable combination of products that the owner or operator expects to manufacture. - (2) If the single highest-HAP recipe serves as the basis for the batch mass input limitation, the batch mass input limitation shall be determined based solely on the production of the single highest-HAP recipe, considering all products produced or processed in the batch unit operation. - (g) **Testing for compliance with § 63.487(a)(3) and (b)(3) [dioxins and furans].** Except as specified in [paragraph (g)(7)](#g-7) of this section, an owner or operator complying with [§ 63.487(a)(3)](/cfr/40/63.487.md?p=a-3) and/or (b)(3) must conduct a performance test using the procedures in [paragraphs (g)(1) through (6)](#g-1..g-6) of this section. Conduct subsequent performance tests no later than 60 calendar months after the previous performance test. - (1) The performance test must consist of three test runs. Collect at least 3 dry standard cubic meters of gas per test run. - (2) Use Method 1 or 1A of appendix A-1 to [40 CFR part 60](/cfr/40/part60.md) to select the sampling sites at the sampling location. The sampling location must be at the outlet of the final control device. - (3) **Determine the gas volumetric flowrate using Method 2, 2A, 2C, or 2D of appendix A-2 to 40 CFR part 60.** - (4) **Use Method 4 of appendix A-3 to 40 CFR part 60 to convert the volumetric flowrate to a dry basis.** - (5) Measure the concentration of each tetra- through octa-chlorinated dioxin and furan congener emitted using Method 23 of appendix A-7 to [40 CFR part 60](/cfr/40/part60.md). - (i) For each dioxin and furan congener, multiply the congener concentration by its corresponding toxic equivalency factor specified in table 10 to this subpart. For determination of toxic equivalency, zero may be used for congeners with a concentration less than the estimated detection limit (EDL). For congeners with estimated maximum pollutant concentration (EMPC) results, if the value is less than the EDL, zero may be used. Otherwise, the EMPC value must be used in the calculation of toxic equivalency. - (ii) Sum the products calculated in accordance with [paragraph (g)(5)(i)](#g-5-i) of this section to obtain the total concentration of dioxins and furans emitted in terms of toxic equivalency. - (6) The concentration of dioxins and furans shall be corrected to 3 percent oxygen. Use Method 3A of appendix A-2 to [40 CFR part 60](/cfr/40/part60.md) or the manual method in ANSI/ASME PTC 19.10-1981 (incorporated by reference, see [§ 63.14](/cfr/40/63.14.md)) to determine the oxygen concentration (%O2d). The oxygen concentration must be determined concurrently with Method 23 of appendix A-7 to [40 CFR part 60](/cfr/40/part60.md). The concentration corrected to 3 percent oxygen (Cc) shall be computed using the following equation: - (7) An owner or operator is not required to conduct a performance test when either a boiler or process heater burning hazardous waste, or hazardous waste incinerator, is used for which the owner or operator: - (i) Has been issued a final permit under [40 CFR part 270](/cfr/40/part270.md) and complies with the requirements of [40 CFR part 266](/cfr/40/part266.md), [subpart H](/cfr/40/subpartH.md); - (ii) Has certified compliance with the interim status requirements of [40 CFR part 266](/cfr/40/part266.md), [subpart H](/cfr/40/subpartH.md); - (iii) Meets the requirement specified in [paragraph (g)(7)(v)](#g-7-v) of this section, and has submitted a Notification of Compliance under [§ 63.1207(j)](/cfr/40/63.1207.md?p=j) and complies with the requirements of [subpart EEE](/cfr/40/subpartEEE.md) of this part; or - (iv) Meets the requirement specified in [paragraph (g)(7)(v)](#g-7-v) of this section, complies with [subpart EEE](/cfr/40/subpartEEE.md) of this part, and will submit a Notification of Compliance under [§ 63.1207(j)](/cfr/40/63.1207.md?p=j) by the date the owner or operator would have been required to submit the initial performance test report for this subpart. - (v) The owner and operator may not waive performance testing pursuant to [§ 63.1207(d)(4)](/cfr/40/63.1207.md?p=d-4) and each performance test required by [§ 63.1207(d)](/cfr/40/63.1207.md?p=d) must show compliance with the dioxins and furans emission limit specified in § [63.487(a)(3)](/cfr/40/63.487.md?p=a-3) and [(b)(3)](/cfr/40/63.487.md?p=b-3), as applicable. # §63.491. Batch front-end process vents—recordkeeping requirements. - (a) **Group determination records for batch front-end process vents.** Except as provided in paragraphs [(a)(7)](#a-7) and [(a)(8)](#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)](#a-1..a-6) of this section for each batch front-end process vent subject to the group determination procedures of [§ 63.488](/cfr/40/63.488.md). Except for [paragraph (a)(1)](#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)](/cfr/40/63.488.md?p=b..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)](#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)](/cfr/40/63.487.md?p=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)](#a-2-i) or [(a)(2)(ii)](#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)](#a-1) of this section that was considered in making the group determination under [§ 63.488](/cfr/40/63.488.md). - (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)](/cfr/40/63.488.md?p=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)](/cfr/40/63.488.md?p=e). - (5) The cutoff flow rate, determined in accordance with [§ 63.488(f)](/cfr/40/63.488.md?p=f). - (6) The results of the batch front-end process vent group determination, conducted in accordance with [§ 63.488(g)](/cfr/40/63.488.md?p=g). - (7) If a batch front-end process vent is subject to [§ 63.487(a)](/cfr/40/63.487.md?p=a) or [§ 63.487(b)](/cfr/40/63.487.md?p=b), none of the records in [paragraphs (a)(1) through (a)(6)](#a-1..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)](/cfr/40/63.488.md?p=d), only the records in [paragraphs (a)(1) through (a)(3)](#a-1..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)](/cfr/40/63.487.md?p=h), the records specified in paragraphs [(a)(9)(i)](#a-9-i) and [(ii)](#a-9-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)](/cfr/40/63.487.md?p=a) or [(b)](/cfr/40/63.487.md?p=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)](/cfr/40/63.488.md?p=h). - (2) If the owner or operator of a batch front-end process vent has chosen to comply with [§ 63.487(a)(2)](/cfr/40/63.487.md?p=a-2), records documenting the batch cycle percent reduction as specified in [§ 63.490(c)(2)](/cfr/40/63.490.md?p=c-2). - (3) Except as specified in [paragraph (b)(3)(iv)](#b-3-iv) of this section, when using a flare to comply with [§ 63.487(a)(1)](/cfr/40/63.487.md?p=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)](/cfr/40/63.504.md?p=c); and - (iii) **Periods when all pilot flames were absent.** - (iv) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n), [paragraphs (b)(3)(i) through (b)(3)(iii)](#b-3-i..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)](/cfr/40/63.108.md?p=m) of [subpart F](/cfr/40/subpartF.md) of this part and [§ 63.508](/cfr/40/63.508.md), readily accessible when using a flare to comply with [§ 63.487(a)(1)](/cfr/40/63.487.md?p=a-1). - (4) The following information when using a control device to meet the percent reduction requirement specified in § [63.487 (a)(2)](/cfr/40/63.487.md?p=a-2) or [(b)(2)](/cfr/40/63.487.md?p=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)](/cfr/40/63.490.md?p=c) for batch front-end process vents and [§ 63.490(e)](/cfr/40/63.490.md?p=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)](/cfr/40/63.490.md?p=c) for batch front-end process vents and [§ 63.490(e)](/cfr/40/63.490.md?p=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)](/cfr/40/63.490.md?p=d-3) or the emission limit determined under [§ 63.490(d)(4)](/cfr/40/63.490.md?p=d-4). - (5) When complying with the 20 parts per million by volume outlet concentration standard specified in [§ 63.487(b)(2)](/cfr/40/63.487.md?p=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)](/cfr/40/63.490.md?p=g). - (c) **Establishment of parameter monitoring level records.** For each parameter monitored according to [§ 63.489(b)](/cfr/40/63.489.md?p=b) and Table 6 of this subpart, or for alternate parameters and/or parameters for alternate control devices monitored according to [§ 63.492(e)](/cfr/40/63.492.md?p=e) as allowed under [§ 63.489(c)](/cfr/40/63.489.md?p=c), maintain documentation showing the establishment of the level that indicates proper operation of the control device as required by [§ 63.489(e)](/cfr/40/63.489.md?p=e) for parameters specified in [§ 63.489(b)](/cfr/40/63.489.md?p=b) and as required by [§ 63.506(f)](/cfr/40/63.506.md?p=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)](#d-1) or [(d)(2)](#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)](/cfr/40/63.487.md?p=g) shall keep the following records readily accessible: - (i) Except as specified in [paragraph (d)(1)(iii)](#d-1-iii) of this section, records designating the established batch mass input limitation required by [§ 63.487(g)(1)](/cfr/40/63.487.md?p=g-1) and specified in [§ 63.490(f)](/cfr/40/63.490.md?p=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](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n), [paragraph (d)(1)(i)](#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)](/cfr/40/63.487.md?p=f) shall keep the following records readily accessible: - (i) Records designating the established batch mass input limitation required by [§ 63.487(f)(1)](/cfr/40/63.487.md?p=f-1) and specified in [§ 63.490(f)](/cfr/40/63.490.md?p=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)](/cfr/40/63.487.md?p=a) shall keep the following records readily accessible: - (1) Continuous records of the equipment operating parameters specified to be monitored under [§ 63.489(b)](/cfr/40/63.489.md?p=b) as applicable, and listed in Table 6 of this subpart, or specified by the Administrator in accordance with [§ 63.492(e)](/cfr/40/63.492.md?p=e) as allowed under [§ 63.489(c)](/cfr/40/63.489.md?p=c). These records shall be kept as specified under [§ 63.506(d)](/cfr/40/63.506.md?p=d), except as specified in paragraphs [(e)(1)(i)](#e-1-i) and [(e)(1)(ii)](#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)](#e-2-iii) of this section, as calculated using the procedures specified in paragraphs [(e)(2)(i)](#e-2-i) and [(e)(2)(ii)](#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)](/cfr/40/63.489.md?p=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)](#e-6) of this section, hourly records of whether the flow indicator for bypass lines specified under [§ 63.489(d)(1)](/cfr/40/63.489.md?p=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)](/cfr/40/63.489.md?p=d-1) is not operating. - (4) Except as specified in [paragraph (e)(6)](#e-6) of this section, where a seal or closure mechanism is used to comply with [§ 63.489(d)(2)](/cfr/40/63.489.md?p=d-2), hourly records of whether a diversion was detected at any time are not required. - (i) For compliance with [§ 63.489(d)(2)](/cfr/40/63.489.md?p=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. - (ii) [Reserved] - (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)](/cfr/40/63.489.md?p=d) for each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=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)](#b) and [(c)](#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)](/cfr/40/63.487.md?p=b-1) or [(b)(2)](/cfr/40/63.487.md?p=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)](/cfr/40/63.489.md?p=b) and listed in Table 6 of this subpart, as applicable, or specified by the Administrator in accordance with [§ 63.492(e)](/cfr/40/63.492.md?p=e), as allowed under [§ 63.489(c)](/cfr/40/63.489.md?p=c), with the exceptions listed in paragraphs [(f)(1)(i)](#f-1-i) and [(f)(1)(ii)](#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)](/cfr/40/63.506.md?p=d). - (3) For demonstrating compliance with the monitoring of bypass lines as specified in [§ 63.489(d)](/cfr/40/63.489.md?p=d), records as specified in paragraph [(e)(3)](#e-3) or [(4)](#e-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)](#g-1..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)](/cfr/40/63.487.md?p=f-1) or [(g)(1)](/cfr/40/63.487.md?p=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)](/cfr/40/63.488.md?p=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)](/cfr/40/63.487.md?p=i), owners and operators must keep the applicable records specified in [paragraphs (h)(1) through (5)](#h-1..h-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)](/cfr/40/63.487.md?p=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)](/cfr/40/63.487.md?p=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)](/cfr/40/63.487.md?p=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)](/cfr/40/63.487.md?p=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)](#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)](#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)](/cfr/40/63.487.md?p=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. # §63.492. Batch front-end process vents—reporting requirements. - (a) The owner or operator of a batch front-end process vent or aggregate batch vent stream at an affected source shall submit the information specified in [paragraphs (a)(1) through (a)(6)](#a-1..a-6) of this section, as appropriate, as part of the Notification of Compliance Status specified in [§ 63.506(e)(5)](/cfr/40/63.506.md?p=e-5). - (1) For each batch front-end process vent complying with [§ 63.487(a)](/cfr/40/63.487.md?p=a) and each aggregate batch vent stream complying with [§ 63.487(b)](/cfr/40/63.487.md?p=b), the information specified in [§ 63.491(b)](/cfr/40/63.491.md?p=b) and [§ 63.491(c)](/cfr/40/63.491.md?p=c), as applicable. - (2) For each Group 2 batch front-end process vent with annual emissions less than the level specified in [§ 63.488(d)](/cfr/40/63.488.md?p=d), the information specified in [§ 63.491(d)(1)(i)](/cfr/40/63.491.md?p=d-1-i). - (3) For each Group 2 batch front-end process vent with annual emissions greater than or equal to the level specified in [§ 63.488(d)](/cfr/40/63.488.md?p=d), the information specified in [§ 63.491(d)(2)(i)](/cfr/40/63.491.md?p=d-2-i). - (4) For each batch process vent subject to the group determination procedures, the information specified in [§ 63.491(a)](/cfr/40/63.491.md?p=a), as appropriate. - (5) 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)](/cfr/40/63.487.md?p=h), the information specified in [§ 63.491(a)(1) through (3)](/cfr/40/63.491.md?p=a-1..a-3), and the information specified in [§ 63.491(a)(4) through (6)](/cfr/40/63.491.md?p=a-4..a-6) as applicable, calculated at the conditions specified in [§ 63.487(h)](/cfr/40/63.487.md?p=h). - (6) When engineering assessment has been used to estimate emissions from a batch emissions episode and the criteria specified in § [63.488(b)(6)(i)(A)](/cfr/40/63.488.md?p=b-6-i-A) or [(B)](/cfr/40/63.488.md?p=b-6-i-B) have been met, the owner or operator shall submit the information demonstrating that the criteria specified in § [63.488(b)(6)(i)(A)](/cfr/40/63.488.md?p=b-6-i-A) or [(B)](/cfr/40/63.488.md?p=b-6-i-B) have been met as part of the Notification of Compliance Status required by [§ 63.506(e)(5)](/cfr/40/63.506.md?p=e-5). - (b) Whenever a process change, as defined in [§ 63.488(i)(1)](/cfr/40/63.488.md?p=i-1), is made that causes a Group 2 batch front-end process vent to become a Group 1 batch front-end process vent, the owner or operator shall notify the Administrator and submit a description of the process change within 180 days after the process change is made or with the next Periodic Report, whichever is later. The owner or operator of an affected source shall comply with the Group 1 batch front-end process vent provisions in [§§ 63.486 through 63.492](/cfr/40/63.486..63.492.md) in accordance with [§ 63.480(i)(2)(ii)](/cfr/40/63.480.md?p=i-2-ii). - (c) Whenever a process change, as defined in [§ 63.488(i)(1)](/cfr/40/63.488.md?p=i-1), is made that causes a Group 2 batch front-end process vent with annual emissions less than the level specified in [§ 63.488(d)](/cfr/40/63.488.md?p=d) for which the owner or operator is required to comply with [§ 63.487(g)](/cfr/40/63.487.md?p=g) to have annual emissions greater than or equal to the level specified in [§ 63.488(d)](/cfr/40/63.488.md?p=d) but remains a Group 2 batch front-end process vent, or if a process change is made that requires the owner or operator to redetermine the batch mass input limitation as specified in [§ 63.488(i)(3)](/cfr/40/63.488.md?p=i-3), the owner or operator shall submit a report within 180 days after the process change is made or with the next Periodic Report, whichever is later. The following information shall be submitted: - (1) A description of the process change; - (2) The batch mass input limitation determined in accordance with [§ 63.487(f)(1)](/cfr/40/63.487.md?p=f-1). - (d) The owner or operator is not required to submit a report of a process change if one of the conditions specified in paragraphs [(d)(1)](#d-1) or [(d)(2)](#d-2) of this section is met. - (1) The change does not meet the description of a process change in [§ 63.488(i)](/cfr/40/63.488.md?p=i). - (2) The redetermined group status remains Group 2 for an individual batch front-end process vent with annual emissions greater than or equal to the level specified in [§ 63.488(d)](/cfr/40/63.488.md?p=d) and the batch mass input limitation does not decrease, or a Group 2 batch front-end process vent with annual emissions less than the level specified in [§ 63.488(d)](/cfr/40/63.488.md?p=d) complying with [§ 63.487(g)](/cfr/40/63.487.md?p=g) continues to have emissions less than the level specified in [§ 63.488(d)](/cfr/40/63.488.md?p=d) and the batch mass input limitation does not decrease. - (e) If an owner or operator uses a control device other than those specified in [§ 63.489(b)](/cfr/40/63.489.md?p=b) and listed in Table 6 of this subpart or requests approval to monitor a parameter other than those specified in [§ 63.489(b)](/cfr/40/63.489.md?p=b) and listed in Table 6 of this subpart, the owner or operator shall submit a description of planned reporting and recordkeeping procedures, as specified in [§ 63.506(f)](/cfr/40/63.506.md?p=f), as part of the Precompliance Report as required under [§ 63.506(e)(3)](/cfr/40/63.506.md?p=e-3). The Administrator will specify appropriate reporting and recordkeeping requirements as part of the review of the Precompliance Report. - (f) Owners or operators of affected sources complying with [§ 63.489(d)](/cfr/40/63.489.md?p=d), shall comply with paragraph [(f)(1)](#f-1) or [(2)](#f-2) of this section, as appropriate. - (1) Submit reports of the times of all periods recorded under [§ 63.491(e)(3)](/cfr/40/63.491.md?p=e-3) when the batch front-end process vent is diverted away from the control device through a bypass line, with the next Periodic Report. Include the start date, start time and duration in hours of each period. - (2) Submit reports of all occurrences recorded under [§ 63.491(e)(4)](/cfr/40/63.491.md?p=e-4) in which the seal mechanism is broken, the bypass line damper or valve position has changed, or the key to unlock the bypass line damper or valve was checked out, with the next Periodic Report. Include the start date, start time and duration in hours of each period. - (g) For any maintenance vent release exceeding the applicable limits in [§ 63.487(i)(1)](/cfr/40/63.487.md?p=i-1), the Periodic Report must include the information specified in [paragraphs (g)(1) through (4)](#g-1..g-4) of this section. For the purposes of this reporting requirement, if an owner or operator complies with [§ 63.487(i)(1)(iv)](/cfr/40/63.487.md?p=i-1-iv), then the owner or operator must report each venting event conducted under those provisions and include an explanation for each event as to why utilization of this alternative was required. - (1) **Identification of the maintenance vent and the equipment served by the maintenance vent.** - (2) **The date and time the maintenance vent was opened to the atmosphere.** - (3) The LEL in percent, vessel pressure in psig, or mass in pounds of VOC in the equipment, as applicable, at the start of atmospheric venting. If the 5 psig vessel pressure option in [§ 63.487(i)(1)(ii)](/cfr/40/63.487.md?p=i-1-ii) was used and active purging was initiated while the concentration of the vapor was 10 percent or greater of its LEL, also include the concentration of the vapors at the time active purging was initiated. - (4) **An estimate of the mass in pounds of organic HAP released during the entire atmospheric venting event.** # §63.493. Back-end process provisions. Owners and operators of new and existing affected sources shall comply with the requirements in [§§ 63.494 through 63.500](/cfr/40/63.494..63.500.md). Owners and operators of affected sources whose only elastomer products are latex products, liquid rubber products, or products produced in a gas-phased reaction process, are not subject to the provisions of [§§ 63.494 through 63.500](/cfr/40/63.494..63.500.md). If latex or liquid rubber products are produced in an affected source that also produces another elastomer product, the provisions of [§§ 63.494 through 63.500](/cfr/40/63.494..63.500.md) do not apply to the back-end operations dedicated to the production of one or more latex products, or to the back-end operations during the production of a latex product. Table 8 to this subpart contains a summary of compliance alternative requirements for the emission limits in [§ 63.494(a)(1)-(3)](/cfr/40/63.494.md?p=a-1..a-3) and associated requirements. # §63.494. Back-end process provisions—residual organic HAP and emission limitations. - (a) The monthly weighted average residual organic HAP content of all grades of styrene butadiene rubber produced by the emulsion process, polybutadiene rubber and styrene butadiene rubber produced by the solution process, and ethylene-propylene rubber produced by the solution process that is processed, shall be measured after the stripping operation (or the reactor(s), if the plant has no stripper(s)), as specified in [§ 63.495(d)](/cfr/40/63.495.md?p=d), and shall not exceed the limits provided in [paragraphs (a)(1) through (3)](#a-1..a-3) of this section, as applicable. Owners or operators of these affected sources shall comply with the requirements of [paragraphs (a)(1) through (3)](#a-1..a-3) of this section using either stripping technology, or control or recovery devices. The organic HAP emissions from all back-end process operations at affected sources producing butyl rubber, epichlorohydrin elastomer, neoprene, and nitrile butadiene rubber shall not exceed the limits determined in accordance with [paragraph (a)(4)](#a-4) of this section, as applicable. - (1) **For styrene butadiene rubber produced by the emulsion process—** - (i) A monthly weighted average of 0.40 kg styrene per megagram (Mg) latex for existing affected sources; and - (ii) A monthly weighted average of 0.23 kg styrene per Mg latex for new sources; - (2) **For polybutadiene rubber and styrene butadiene rubber produced by the solution process—** - (i) A monthly weighted average of 10 kg total organic HAP per Mg crumb rubber (dry weight) for existing affected sources; and - (ii) **A monthly weighted average of 6 kg total organic HAP per Mg crumb rubber (dry weight) for new sources.** - (3) **For ethylene-propylene rubber produced by the solution process—** - (i) A monthly weighted average of 8 kg total organic HAP per Mg crumb rubber (dry weight) for existing affected sources; and - (ii) **A monthly weighted average of 5 kg total organic HAP per Mg crumb rubber (dry weight) for new sources.** - (4) In addition to the requirements specified in [paragraph (a)(7)](#a-7) of this section, the organic HAP emissions from back-end processes at affected sources producing butyl rubber, epichlorohydrin elastomer, neoprene, and nitrile butadiene rubber shall not exceed the limits determined in accordance with [paragraphs (a)(4)(i) through (iv)](#a-4-i..a-4-iv) of this section for any consecutive 12-month period. The specific limitation for each elastomer type shall be determined based on the calculation or the emissions level provided in [paragraphs (a)(4)(i) through (iv)](#a-4-i..a-4-iv) of this section divided by the base year elastomer product that leaves the stripping operation (or the reactor(s), if the plant has no stripper(s)). The limitation shall be calculated and submitted in accordance with [§ 63.499(f)(1)](/cfr/40/63.499.md?p=f-1). - (i) For butyl rubber, the organic HAP emission limitation shall be calculated using the following equation: - (ii) For epichlorohydrin elastomer, the organic HAP emission limitation, in units of Mg organic HAP emissions per Mg of epichlorohydrin elastomer produced, shall be calculated by dividing 51 Mg/yr by the mass of epichlorohydrin elastomer produced in 2009, in Mg. - (iii) For neoprene, the organic HAP emission limitation, in units of Mg organic HAP emissions per Mg of neoprene produced, shall be calculated by dividing 30 Mg/yr by the mass of neoprene produced in 2007, in Mg. - (iv) For nitrile butadiene rubber, the organic HAP emission limitation, in units of Mg organic HAP emissions per Mg of nitrile butadiene rubber produced, shall be calculated by dividing 2.4 Mg/yr by the mass of nitrile butadiene rubber produced in 2009, in Mg. - (5) For EPPU that produce both an elastomer product with a residual organic HAP limitation listed in [paragraphs (a)(1) through (3)](#a-1..a-3) of this section, and a product listed in [paragraphs (a)(5)(i) through (iv)](#a-5-i..a-5-iv) of this section, only the residual HAP content of the elastomer product with a residual organic HAP limitation shall be used in determining the monthly average residual organic HAP content. - (i) Resins; - (ii) Liquid rubber products; - (iii) Latexes from which crumb rubber is not coagulated; or - (iii) **Elastomer products listed in paragraph (a)(4) of this section.** - (6) There are no back-end process operation residual organic HAP or emission limitations for Hypalon TM and polysulfide rubber production. There are also no back-end process operation residual organic HAP limitations for latex products, liquid rubber products, products produced in a gas-phased reaction process, styrene butadiene rubber produced by any process other than a solution or emulsion process, polybutadiene rubber produced by any process other than a solution process, or ethylene-propylene rubber produced by any process other than a solution process. - (7) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(o)](/cfr/40/63.481.md?p=o), if the back-end process vent contains chloroprene such that it is considered to be in chloroprene service, as defined in [§ 63.482](/cfr/40/63.482.md), then the owner or operator must comply with the requirements of [paragraphs (a)(7)(i) through (iii)](#a-7-i..a-7-iii) of this section in addition to all other applicable requirements specified in [§ 63.483](/cfr/40/63.483.md) and elsewhere in this section. - (i) Reduce emissions of chloroprene by venting emissions through a closed vent system to a non-flare control device that reduces chloroprene by greater than or equal to 98 percent by weight, or to a concentration less than 1 ppmv for each process vent or to less than 5 pounds per year for all combined process vents within the process. If a combustion device is used, the chloroprene concentration of 1 ppmv must be corrected to 3 percent oxygen. - (ii) To demonstrate compliance with the emission limits specified in [paragraph (a)(7)(i)](#a-7-i) of this section for back-end process vents in chloroprene service, owners and operators must meet the requirements specified in [§ 63.510](/cfr/40/63.510.md). - (iii) An owner or operator may designate a back-end process vent in chloroprene service as a maintenance vent if the vent is only used as a result of startup, shutdown, maintenance, or inspection of equipment where equipment is emptied, depressurized, degassed, or placed into service; however, owners and operators may not release more than 1.0 tons of chloroprene from all maintenance vents combined (i.e., including maintenance vents subject to this [paragraph (a)(7)(iii)](#a-7-iii), [§ 63.485(z)](/cfr/40/63.485.md?p=z), or [§ 63.487(i)(4)](/cfr/40/63.487.md?p=i-4)) per any consecutive 12-month period. The owner or operator must keep monthly records of the quantity in tons of chloroprene released from each maintenance vent and include a description of the method used to estimate this quantity. - (b) If an owner or operator complies with the residual organic HAP limitations in [paragraph (a)(1) through (3)](#a-1..a-3) of this section using stripping technology, compliance shall be demonstrated in accordance with [§ 63.495](/cfr/40/63.495.md). The owner or operator shall also comply with the recordkeeping provisions in [§ 63.498](/cfr/40/63.498.md), and the reporting provisions in [§ 63.499](/cfr/40/63.499.md). - (c) If an owner or operator complies with the residual organic HAP limitations in [paragraph (a)(1) through (3)](#a-1..a-3) of this section using control or recovery devices, compliance shall be demonstrated using the procedures in [§ 63.496](/cfr/40/63.496.md). The owner or operator shall also comply with the monitoring provisions in [§ 63.497](/cfr/40/63.497.md), the recordkeeping provisions in [§ 63.498](/cfr/40/63.498.md), and the reporting provisions in [§ 63.499](/cfr/40/63.499.md). - (d) Except as specified in [paragraph (e)](#e) of this section, if the owner or operator complies with the residual organic HAP limitations in [paragraph (a)(1) through (3)](#a-1..a-3) of this section using a flare, the owner or operator of an affected source shall comply with the requirements in [§ 63.504(c)](/cfr/40/63.504.md?p=c). - (e) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n), [paragraph (d)](#d) of this section no longer applies and instead if the owner or operator complies with the residual organic HAP limitations in [paragraph (a)(1) through (3)](#a-1..a-3) of this section using a flare, the owner or operator of the affected source must comply with [§ 63.508](/cfr/40/63.508.md) for the flare. # §63.495. Back-end process provisions—procedures to determine compliance with residual organic HAP limitations using stripping technology and organic HAP emissions limitations. - (a) If an owner or operator complies with the residual organic HAP limitations in [§ 63.494(a)(1) through (3)](/cfr/40/63.494.md?p=a-1..a-3) using stripping technology, compliance shall be demonstrated using the periodic sampling procedures in [paragraph (b)](#b) of this section, or using the stripper parameter monitoring procedures in [paragraph (c)](#c) of this section. The owner or operator shall determine the monthly weighted average residual organic HAP content for each month in which any portion of the back-end of an elastomer production process is in operation. A single monthly weighted average shall be determined for all back-end process operations at the affected source. - (b) If the owner or operator is demonstrating compliance using periodic sampling, this demonstration shall be in accordance with [paragraphs (b)(1) through (b)(5)](#b-1..b-5) of this section, - (1) The location of the sampling shall be in accordance with [paragraph (d)](#d) of this section. - (2) The frequency of the sampling shall be in accordance with paragraphs [(b)(2)(i)](#b-2-i) or [(b)(2)(ii)](#b-2-ii) of this section. - (i) If a stripper operated in batch mode is used, at least one representative sample is to be taken from every batch of elastomer produced, at the location specified in [paragraph (d)](#d) of this section, and identified by elastomer type and by the date and time the batch is completed. - (ii) If a stripper operated in continuous mode is used, at least one representative sample is to be taken each operating day. The sample is to be taken at the location specified in [paragraph (d)](#d) of this section, and identified by elastomer type and by the date and time the sample was taken. - (3) The residual organic HAP content in each sample is to be determined using the Methods specified in [paragraph (e)](#e) of this section. - (4) The quantity of material (weight of latex or dry crumb rubber) represented by each sample shall be recorded. Acceptable methods of determining this quantity are production records, measurement of stream characteristics, and engineering calculations. - (5) The monthly weighted average shall be determined using the equation in [paragraph (f)](#f) of this section. All representative samples taken and analyzed during the month shall be used in the determination of the monthly weighted average. - (c) If the owner or operator is demonstrating compliance using stripper parameter monitoring, this demonstration shall be in accordance with [paragraphs (c)(1) through (c)(4)](#c-1..c-4) of this section. - (1) The owner or operator shall establish stripper operating parameter levels for each grade in accordance with [§ 63.505(e)](/cfr/40/63.505.md?p=e). - (2) The owner or operator shall monitor the stripper operating parameters at all times the stripper is in operation. Readings of each parameter shall be made at intervals no greater than 15 minutes. - (3) The residual organic HAP content for each grade shall be determined in accordance with either paragraph [(c)(3)(i)](#c-3-i) or [(c)(3)(ii)](#c-3-ii) of this section. - (i) If during the processing of a grade in the stripper, all hourly average parameter values are in accordance with operating parameter levels established in [paragraph (c)(1)](#c-1) of this section, the owner or operator shall use the residual organic HAP content determined in accordance with [§ 63.505(e)(1)](/cfr/40/63.505.md?p=e-1). - (ii) If during the processing of a grade in the stripper, the hourly average of any stripper monitoring parameter is not in accordance with an established operating parameter level, the residual organic HAP content shall be determined using the procedures in paragraphs [(b)(1)](#b-1) and [(b)(3)](#b-3) of this section. - (4) The monthly weighted average shall be determined using the equation in [paragraph (f)](#f) of this section. - (d) The location of the sampling shall be in accordance with paragraph [(d)(1)](#d-1) or [(d)(2)](#d-2) of this section. - (1) For styrene butadiene rubber produced by the emulsion process, the sample shall be a sample of the latex taken at the location specified in either paragraph [(d)(1)(i)](#d-1-i), [(d)(1)(ii)](#d-1-ii), or [(d)(1)(iii)](#d-1-iii) of this section. - (i) When the latex is not blended with other materials or latexes, the sample shall be taken at a location meeting all of the following criteria: - (A) After the stripping operation, - (B) Prior to entering the coagulation operations, and - (C) **Before the addition of carbon black or oil extenders.** - (ii) When two or more latexes subject to this subpart are blended, samples may be taken in accordance with either [paragraph (d)(1)(ii)](#d-1-ii) (A) or (B) of this section, at a location meeting the requirements of [paragraphs (d)(1)(i)](#d-1-i) (A) through (C) of this section. - (A) Individual samples may be taken of each latex prior to blending, or - (B) A sample of the blended latex may be taken. - (iii) When a latex subject to this subpart is blended with a latex or material not subject to this subpart, a sample shall be taken of the latex prior to blending at a location meeting the requirements of [paragraphs (d)(1)(i)](#d-1-i) (A) through (C) of this section. - (2) For styrene butadiene rubber produced by the solution process, polybutadiene rubber produced by the solution process, and ethylene-propylene rubber produced by the solution process, the sample shall be a sample of crumb rubber taken as soon as safe and feasible after the stripping operation, but no later than the entry point for the first unit operation following the stripper (e.g., the dewatering screen). - (e) The residual organic HAP content in each sample is to be determined using the methods specified in [paragraphs (e)(1) through (e)(5)](#e-1..e-5) of this section, as applicable. - (1) For styrene butadiene rubber produced by the emulsion process, either Method 312a, 312b, or 312c of [40 CFR part 63](/cfr/40/part63.md), appendix A, shall be used. - (2) For styrene butadiene rubber produced by the solution process, either Method 313a or 313b of [40 CFR part 63](/cfr/40/part63.md), appendix A, shall be used. - (3) For polybutadiene rubber produced by the solution process, either Method 313a or 313b of [40 CFR part 63](/cfr/40/part63.md), appendix A, shall be used. - (4) For ethylene-propylene rubber produced by the solution process, either Method 310a, 310b, or 310c of [40 CFR part 63](/cfr/40/part63.md), appendix A, shall be used. - (5) Alternatively, any other method that has been validated according to the applicable procedures in Method 301 of [40 CFR part 63](/cfr/40/part63.md), appendix A, may be used. - (f) The monthly weighted average residual organic HAP content shall be calculated using Equation 26. - (g) Compliance with the organic HAP emission limitations determined in accordance with [§ 63.494(a)(4)](/cfr/40/63.494.md?p=a-4) shall be demonstrated in accordance with [paragraphs (g)(1) through (5)](#g-1..g-5) of this section. - (1) Calculate your organic HAP emission limitation in accordance with [§ 63.494(a)(4)(i) through (iv)](/cfr/40/63.494.md?p=a-4-i..a-4-iv), as applicable, record it, and submit it in accordance with [§ 63.499(f)(1)](/cfr/40/63.499.md?p=f-1). - (2) Each month, calculate and record the organic HAP emissions from all back-end process operations using engineering assessment. Engineering assessment includes, but is not limited to, the following: - (i) **Previous test results, provided the test was representative of current operating practices.** - (ii) Bench-scale or pilot-scale test data obtained under conditions representative of current process operating conditions. - (iii) Design analysis based on accepted chemical engineering principles, measurable process parameters, or physical or chemical laws or properties. Examples of analytical methods include, but are not limited to: - (A) Use of material balances; - (B) Estimation of flow rate based on physical equipment design, such as pump or blower capacities; - (C) Estimation of organic HAP concentrations based on saturation conditions; and - (D) **Estimation of organic HAP concentrations based on grab samples of the liquid or vapor.** - (3) **Each month, record the mass of elastomer product produced.** - (4) Each month, calculate and record the sums of the organic HAP emissions and the mass of elastomer produced for the previous calendar 12-month period. - (5) Each month, divide the total mass of organic HAP emitted for the previous calendar 12-month period by the total mass of elastomer produced during this 12-month period. This value must be recorded in accordance with [§ 63.498(e)](/cfr/40/63.498.md?p=e) and reported in accordance with [§ 63.499(f)(2)](/cfr/40/63.499.md?p=f-2). # §63.496. Back-end process provisions—procedures to determine compliance with residual organic HAP limitations using control or recovery devices. - (a) If an owner or operator complies with the residual organic HAP limitations in [§ 63.494(a)(1) through (3)](/cfr/40/63.494.md?p=a-1..a-3) using control or recovery devices, compliance shall be demonstrated using the procedures in paragraphs [(b)](#b) and [(c)](#c) of this section. Previous test results conducted in accordance with [paragraphs (b)(1) through (6)](#b-1..b-6) of this section may be used to determine compliance in accordance with [paragraph (c)](#c) of this section. - (b) Compliance shall be demonstrated using the provisions in [paragraphs (b)(1) through (b)(8)](#b-1..b-8) of this section, as applicable. - (1) A test shall be conducted, the duration of which shall be in accordance with either paragraph [(b)(1)(i)](#b-1-i) or [(b)(1)(ii)](#b-1-ii) of this section, as appropriate. - (i) If the back-end process operations are continuous, the test shall consist of three separate one hour runs. - (ii) If the back-end process operations are batch, the test shall consist of three separate one-hour runs, unless the duration of the batch cycle is less than one-hour, in which case the run length shall equal the complete duration of the back-end process batch cycle. - (2) The test shall be conducted when the grade of elastomer product with the highest residual organic HAP content leaving the stripper is processed in the back-end operations. - (3) The uncontrolled residual organic HAP content in the latex or dry crumb rubber shall be determined in accordance with § [63.495(b)(1)](/cfr/40/63.495.md?p=b-1) and [(b)(3)](/cfr/40/63.495.md?p=b-3). A separate sample shall be taken and analyzed for each test run. The sample shall be representative of the material being processed in the back-end operation during the test, and does not need to be taken during the test. - (4) The quantity of material (weight of latex or dry crumb rubber) processed during the test run shall be recorded. Acceptable methods of determining this quantity are production records, measurement of stream characteristics, and engineering calculations. - (5) The inlet and outlet emissions from the control or recovery device shall be determined using the procedures in [paragraphs (b)(5)(i) through (b)(5)(v)](#b-5-i..b-5-v) of this section, with the exceptions noted in paragraphs [(b)(6)](#b-6) and [(b)(7)](#b-7) of this section. The inlet and outlet emissions shall be determined when the material for which the uncontrolled residual organic HAP content is determined in accordance with [paragraph (b)(3)](#b-3) of this section, is being processed in the equipment controlled by the control or recovery device. - (i) Method 1 or 1A of [40 CFR part 60](/cfr/40/part60.md), appendix A, as appropriate, shall be used for selection of the sampling sites. Sampling sites for inlet emissions shall be located as specified in paragraphs [(b)(5)(i)(A)](#b-5-i-A) or [(b)(5)(i)(B)](#b-5-i-B) of this section. Sampling sites for outlet emissions shall be located at the outlet of the control or recovery device. - (A) The inlet sampling site shall be located at the exit of the back-end process unit operation before any opportunity for emission to the atmosphere [with the exception of equipment in compliance with the requirements in [§§ 63.502(a) through 63.502(m)](/cfr/40/63.502.md?p=a..m)], and before any control or recovery device. - (B) If back-end process vent streams are combined prior to being routed to control or recovery devices, the inlet sampling site may be for the combined stream, as long as there is no opportunity for emission to the atmosphere [with the exception of equipment in compliance with the requirements in [§§ 63.502(a) through 63.502(m)](/cfr/40/63.502.md?p=a..m)] from any of the streams prior to being combined. - (ii) The gas volumetric flow rate shall be determined using Method 2, 2A, 2C, or 2D of [40 CFR part 60](/cfr/40/part60.md), appendix A, as appropriate. - (iii) To determine the inlet and outlet total organic HAP concentrations, the owner or operator must use Method 18 or Method 25A of appendices A-6 and A-7 to [40 CFR part 60](/cfr/40/part60.md), respectively. ASTM D6420-18 (incorporated by reference, see [§ 63.14](/cfr/40/63.14.md)) may also be used in lieu of Method 18, if the target compounds are all known and are all listed in [Section 1.1](/cfr/40/1.1.md) of ASTM D6420-18 as measurable; ASTM D6420-18 must not be used for methane and ethane; and ASTM D6420-18 may not be used as a total VOC method. Alternatively, any other method or data that has been validated according to the applicable procedures in Method 301 of appendix A to this part may be used. The minimum sampling time for each run must be in accordance with [paragraph (b)(1)](#b-1) of this section, during which either an integrated sample or grab samples shall be taken. If grab sampling is used, then the samples must be taken at approximately equal intervals during the run, with the time between samples no greater than 15 minutes. - (iv) The mass rate of total organic HAP shall be computed using Equations 27 and 28. - (v) Inlet and outlet organic HAP emissions for the run shall be calculated by multiplying the mass rate total inlet and outlet emissions determined in accordance with [paragraph (b)(5)(iv)](#b-5-iv) of this section by the duration of the run (in hours). - (6) If a back-end process vent stream is introduced with the combustion air, or as a secondary fuel into a boiler or process heater with a design capacity less than 44 megawatts, the inlet and outlet emissions shall be determined in accordance with [paragraphs (b)(6)(i) through (b)(6)(iv)](#b-6-i..b-6-iv) of this section. - (i) The inlet organic HAP emissions for the back-end process unit operation shall be determined in accordance with [paragraph (b)(5)](#b-5) of this section. - (ii) The owner or operator shall also measure total organic HAP (or TOC, minus methane and ethane) emissions in all process vent streams and primary and secondary fuels introduced into the boiler or process heater, using the procedures in [paragraph (b)(5)](#b-5) of this section, with the exceptions noted in [paragraphs (b)(6)(ii)(A) through (b)(6)(ii)(C)](#b-6-ii-A..b-6-ii-C) of this section. - (A) Selection of the location of the inlet sampling sites shall ensure the measurement of total organic HAP concentrations in all process vent streams and primary and secondary fuels introduced into the boiler or process heater. - (B) [Paragraph (b)(5)(iii)](#b-5-iii) of this section is applicable, except that TOC (minus methane and ethane) may be measured instead of total organic HAP. - (C) The mass rates shall be calculated in accordance with [paragraph (b)(5)(iv)](#b-5-iv) of this section, except that Cj at the inlet and outlet of the control device shall be the sum of all total organic HAP (or TOC, minus methane and ethane) concentrations for all process vent streams and primary and secondary fuels introduced into the boiler or process heater. - (iii) The control efficiency of the boiler or process heater shall be calculated using Equation 29. - (iv) The outlet total organic HAP emissions associated with the back-end process unit operation shall be calculated using Equation 30, as shown in [paragraph (b)(8)](#b-8) of this section. - (7) An owner or operator is not required to conduct a source test to determine the outlet organic HAP emissions if any control device specified in [paragraphs (b)(7)(i) through (b)(7)(vi)](#b-7-i..b-7-vi) of this section is used. For these devices, the inlet emissions associated with the back-end process unit operation shall be determined in accordance with [paragraph (b)(5)](#b-5) of this section, and the outlet emissions shall be calculated using the equation in [paragraph (b)(8)](#b-8) of this section. - (i) **A flare.** - (A) Except as specified in [paragraph (b)(7)(i)(B)](#b-7-i-B) of this section, the owner or operator shall demonstrate compliance as provided in [§ 63.504(c)](/cfr/40/63.504.md?p=c). - (B) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n), [paragraph (b)(7)(i)(A)](#b-7-i-A) of this section no longer applies and instead the owner or operator of the affected source must comply with [§ 63.508](/cfr/40/63.508.md) for the flare. - (ii) **A boiler or process heater with a design heat input capacity of 44 megawatts or greater.** - (iii) A boiler or process heater into which the process vent stream is introduced with the primary fuel or is used as the primary fuel. - (iv) A control device for which a performance test was conducted for determining compliance with a regulation promulgated by the EPA and the test was conducted using the same Methods specified in this section and either no deliberate 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. - (v) **A boiler or process heater burning hazardous waste for which the owner or operator—** - (A) Has been issued a final permit under [40 CFR part 270](/cfr/40/part270.md) and complies with the requirements of [40 CFR part 266](/cfr/40/part266.md), [subpart H](/cfr/40/subpartH.md), or - (B) **Has certified compliance with the interim status requirements of 40 CFR part 266, subpart H.** - (vi) A hazardous waste incinerator for which the owner or operator has been issued a final permit under [40 CFR Part 270](/cfr/40/part270.md) and complies with the requirements of [40 CFR part 264](/cfr/40/part264.md), [subpart O](/cfr/40/subpartO.md), or has certified compliance with the interim status requirements of [40 CFR part 265](/cfr/40/part265.md), subpart O. - (8) If one of the control devices listed in paragraph [(b)(6)](#b-6) or [(b)(7)](#b-7) of this section is used, the outlet emissions shall be calculated using Equation 30. - (i) If a back-end process vent stream is introduced with the combustion air, or as a secondary fuel into a boiler or process heater with a design capacity less than 44 megawatts, the control efficiency of the boiler or process heater shall be determined using the procedures in [paragraph (b)(6)(iii)](#b-6-iii) of this section. - (ii) If a back-end process vent is controlled using a control device specified in [paragraph (b)(7)](#b-7) (i), (ii), (iii), or (v) of this section, the control device efficiency shall be assumed to be 98 percent. - (iii) If a back-end process vent is controlled using a control device specified in [paragraph (b)(7)(iv)](#b-7-iv) of this section, the control device efficiency shall be the efficiency determined in the previous performance test. - (c) Compliance shall be determined using the procedures in this paragraph. - (1) For each test run, the residual organic HAP content, adjusted for the control or recovery device emission reduction, shall be calculated using Equation 31. - (2) A facility is in compliance if the average of the organic HAP contents calculated for all three test runs is below the residual organic HAP limitations in [§ 63.494(a)(1) through (3)](/cfr/40/63.494.md?p=a-1..a-3). - (d) An owner or operator complying with the residual organic HAP limitations in [§ 63.494(a)(1) through (3)](/cfr/40/63.494.md?p=a-1..a-3) using a control or recovery device, shall redetermine the compliance status through the requirements described in [paragraph (b)](#b) of this section whenever process changes are made. The owner or operator shall report the results of the redetermination in accordance with [§ 63.499(d)](/cfr/40/63.499.md?p=d). For the purposes of this section, a process change is any action that would reasonably be expected to impair the performance of the control or recovery device. For the purposes of this section, the production of an elastomer with a residual organic HAP content greater than the residual organic HAP content of the elastomer used in the compliance demonstration constitutes a process change, unless the overall effect of the change is to reduce organic HAP emissions from the source as a whole. Other examples of process changes may include changes in production capacity or production rate, or removal or addition of equipment. For the purposes of this paragraph, process changes do not include: Process upsets; unintentional, temporary process changes; or changes that reduce the residual organic HAP content of the elastomer. # §63.497. Back-end process provisions—monitoring provisions for control and recovery devices used to comply with residual organic HAP limitations. - (a) An owner or operator complying with the residual organic HAP limitations in [§ 63.494(a)(1) through (3)](/cfr/40/63.494.md?p=a-1..a-3) using control or recovery devices, or a combination of stripping and control or recovery devices, shall install the monitoring equipment specified in [paragraphs (a)(1) through (7)](#a-1..a-7) of this section, as appropriate. - (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, the 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, the 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 [paragraph (a)(7)](#a-7) of this section, 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 is required. - (3) Where a boiler or process heater of less than 44 megawatts design heat input capacity is used, a temperature monitoring device in the firebox equipped with a continuous recorder is required. Any boiler or process heater in which all vent streams are introduced with primary fuel or are used as the primary fuel is exempt from this requirement. - (4) For an absorber, a scrubbing liquid temperature monitoring device and a specific gravity monitoring device are required, each equipped with a continuous recorder. - (5) For a condenser, a condenser exit (product side) temperature monitoring device equipped with a continuous recorder is required. - (6) Except as specified in [paragraph (a)(8)](#a-8) of this section, for a carbon adsorber, an integrating regeneration steam flow, nitrogen flow, or pressure monitoring device having an accuracy of at least ±10 percent of the flow rate, level, or pressure, capable of recording the total regeneration steam flow or nitrogen flow, or pressure (gauge or absolute) 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 are required. - (7) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n), [paragraph (a)(2)](#a-2) of this section no longer applies and instead the owner or operator of the affected source must comply with [§ 63.508](/cfr/40/63.508.md) for the flare. - (8) Beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n), 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)(8)(i) through (iii)](#a-8-i..a-8-iii) of this section. - (i) Conduct an initial performance test or design evaluation of the adsorber and establish the breakthrough limit and adsorber bed life. - (ii) 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)(8)(iii)(B)](#a-8-iii-B) 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 [40 CFR part 60](/cfr/40/part60.md), appendix A-7 using methane, propane, isobutylene, or the primary HAP being controlled as the calibration gas or Method 25A of [40 CFR part 60](/cfr/40/part60.md), appendix A-7 using methane, propane, or the primary HAP being controlled as the calibration gas. - (iii) Comply with [paragraph (a)(8)(iii)(A)](#a-8-iii-A) of this section, and comply with the monitoring frequency according to [paragraph (a)(8)(iii)(B)](#a-8-iii-B) of this section. - (A) The first adsorber in series must be replaced immediately when breakthrough, as defined in [§ 63.482](/cfr/40/63.482.md), 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. - (B) Based on the adsorber bed life established according to [paragraph (a)(8)(i)](#a-8-i) 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. - (b) An owner or operator may request approval to monitor parameters other than those required by [paragraph (a)](#a) of this section. The request shall be submitted according to the procedures specified in § [63.506(f)](/cfr/40/63.506.md?p=f) or [(g)](/cfr/40/63.506.md?p=g). Approval shall be requested if the owner or operator: - (1) Uses a control or recovery device other than those listed in [paragraph (a)](#a) of this section; or - (2) Uses one of the control or recovery devices listed in [paragraph (a)](#a) of this section, but seeks to monitor a parameter other than those specified in [paragraph (a)](#a) of this section. - (c) The owner or operator shall establish a level, defined as either a maximum or minimum operating parameter, that indicates proper operation of the control or recovery device for each parameter monitored under [paragraphs (a)(1) through (a)(6)](#a-1..a-6) of this section. This level is determined in accordance with [§ 63.505](/cfr/40/63.505.md). The established level, along with supporting documentation, shall be submitted in the Notification of Compliance Status or the operating permit application, as required in § [63.506(e)(5)](/cfr/40/63.506.md?p=e-5) or [(e)(8)](/cfr/40/63.506.md?p=e-8), respectively. The owner or operator shall operate control and recovery devices so that the daily average value is above or below the established level, as required, to ensure continued compliance with the standard, except as otherwise stated in this subpart. - (d) The owner or operator of an affected source with a controlled back-end process vent using a vent system that contains bypass lines that could divert a vent stream away from the control or recovery device used to comply with [§ 63.494(a)(1) through (3)](/cfr/40/63.494.md?p=a-1..a-3), shall comply with either paragraph [(d)(1)](#d-1) or [(d)(2)](#d-2), and [(d)(3)](#d-3) of this section. Except as specified in [paragraph (d)(3)](#d-3) 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. - (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 [§ 63.498(d)(5)(iii)](/cfr/40/63.498.md?p=d-5-iii). The flow indicator shall be installed at the entrance to any bypass line that could divert the vent stream away from the control device 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 vent stream is not diverted through the bypass line. - (3) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n): - (i) The use of a bypass line at any time on a closed vent system to divert emissions (subject to the emission standards in [§ 63.487](/cfr/40/63.487.md)) 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 paragraph [(d)(3)(ii)(A)](#d-3-ii-A) and [(d)(3)(ii)(B)](#d-3-ii-B) of this section apply. - (A) Except for pressure relief devices subject to [§ 63.165(e)(4)](/cfr/40/63.165.md?p=e-4) of [subpart H](/cfr/40/subpartH.md) of this part, equipment such as low leg drains and equipment subject to the requirements of [subpart H](/cfr/40/subpartH.md) of this part are not subject to this [paragraph (d)](#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 40 CFR [60.482-6(a)(2)](/cfr/40/60.482-6.md?p=a-2), [(b)](/cfr/40/60.482-6.md?p=a-b), and [(c)](/cfr/40/60.482-6.md?p=a-c) or follow requirements codified in another regulation that are the same as 40 CFR [60.482-6(a)(2)](/cfr/40/60.482-6.md?p=a-2), [(b)](/cfr/40/60.482-6.md?p=a-b), and [(c)](/cfr/40/60.482-6.md?p=a-c) are not subject to this [paragraph (d)](#d) of this section. # §63.498. Back-end process provisions—recordkeeping. - (a) Each owner or operator shall maintain the records specified in [paragraphs (a)(1) through (4)](#a-1..a-4), and [paragraphs (b) through (f)](#b..f) of this section, as appropriate. - (1) **The type of elastomer product processed in the back-end operation.** - (2) The type of process (solution process, emulsion process, etc.) - (3) If the back-end process operation is subject to a residual organic HAP limitation in [§ 63.494(a)(1) through (3)](/cfr/40/63.494.md?p=a-1..a-3), whether compliance will be achieved by stripping technology, or by control or recovery devices. - (4) If the back-end process operation is subject to an emission limitation in [§ 63.494(a)(4)](/cfr/40/63.494.md?p=a-4), the organic HAP emission limitation calculated in accordance with [§ 63.494(a)(4)(i) through (iv)](/cfr/40/63.494.md?p=a-4-i..a-4-iv), as applicable. - (b) Each owner or operator of a back-end process operation using stripping technology to comply with a residual organic HAP limitation in [§ 63.494(a)(1) through (3)](/cfr/40/63.494.md?p=a-1..a-3), and demonstrating compliance using the periodic sampling procedures in [§ 63.495(b)](/cfr/40/63.495.md?p=b), shall maintain the records specified in [paragraph (b)(1)](#b-1), and in [paragraph (b)(2)](#b-2) or [paragraph (b)(3)](#b-3) of this section, as appropriate. - (1) Records associated with each sample taken in accordance with [§ 63.495(b)](/cfr/40/63.495.md?p=b). These records shall include the following for each sample: - (i) Elastomer type, - (ii) The date and time the sample was collected, - (iii) **The corresponding quantity of elastomer processed over the time period represented by the sample.** Acceptable methods of determining this quantity are production records, measurement of stream characteristics, and engineering calculations. - (A) For emulsion processes, this quantity shall be the weight of the latex leaving the stripper. - (B) For solution processes, this quantity shall be the crumb rubber dry weight of the rubber leaving the stripper. - (iv) **The organic HAP content of each sample.** - (2) The monthly weighted average organic HAP content, calculated in accordance with [§ 63.495(f)](/cfr/40/63.495.md?p=f). - (3) If the organic HAP contents for all samples analyzed during a month are below the appropriate level in [§ 63.494(a)](/cfr/40/63.494.md?p=a), the owner or operator may record that all samples were in accordance with the residual organic HAP limitations in [§ 63.494(a)(1) through (3)](/cfr/40/63.494.md?p=a-1..a-3), rather than calculating and recording a monthly weighted average. - (c) Each owner or operator of a back-end process operation using stripping technology to comply with a residual organic HAP limitation in [§ 63.494(a)(1) through (3)](/cfr/40/63.494.md?p=a-1..a-3), and demonstrating compliance using the stripper parameter monitoring procedures in [§ 63.495(c)](/cfr/40/63.495.md?p=c), shall maintain the records specified in [paragraphs (c)(1) through (3)](#c-1..c-3) of this section. - (1) Records associated with the initial, and subsequent, determinations of the organic HAP content of each grade of elastomer produced. These records shall include the following: - (i) An identification of the elastomer type and grade; - (ii) The results of the residual organic HAP analyses, conducted in accordance with [§ 63.505(e)(1)](/cfr/40/63.505.md?p=e-1); - (iii) The stripper monitoring parameters required to be established in [§ 63.495(c)(1)](/cfr/40/63.495.md?p=c-1). - (iv) If re-determinations are made of the organic HAP content, and re-establishment of the stripper monitoring parameters, records of the initial determination are no longer required to be maintained. - (2) **Records associated with each grade or batch.** These records shall include the following for each grade or batch: - (i) Elastomer type and grade; - (ii) The quantity of elastomer processed; - (A) For emulsion processes, this quantity shall be the weight of the latex leaving the stripper. - (B) For solution processes, this quantity shall be the crumb rubber dry weight of the crumb rubber leaving the stripper. - (iii) The hourly average of all stripper parameter results; - (iv) If one or more hourly average stripper monitoring parameters is not in accordance with the established levels, the results of the residual organic HAP analysis. - (3) The monthly weighted average organic HAP content, calculated in accordance with [§ 63.495(f)](/cfr/40/63.495.md?p=f). - (d) Each owner or operator of a back-end process operation using control or recovery devices to comply with a residual organic HAP limitation in [§ 63.494(a)(1) through (3)](/cfr/40/63.494.md?p=a-1..a-3), shall maintain the records specified in [paragraphs (d)(1) through (5)](#d-1..d-5) of this section. The recordkeeping requirements contained in [paragraphs (d)(1) through (4)](#d-1..d-4) pertain to the results of the testing required by [§ 63.496(b)](/cfr/40/63.496.md?p=b), for each of the three required test runs. - (1) The uncontrolled residual organic HAP content in the latex or dry crumb rubber, as required to be determined by [§ 63.496(b)(3)](/cfr/40/63.496.md?p=b-3), including the test results of the analysis; - (2) The total quantity of material (weight of latex or dry crumb rubber) processed during the test run, recorded in accordance with [§ 63.496(b)(4)](/cfr/40/63.496.md?p=b-4); - (3) The organic HAP emissions at the inlet and outlet of the control or recovery device, determined in accordance with [§ 63.496(b)(5) through (8)](/cfr/40/63.496.md?p=b-5..b-8), including all test results and calculations. - (4) The residual organic HAP content, adjusted for the control or recovery device emission reduction, determined in accordance with [§ 63.496(c)(1)](/cfr/40/63.496.md?p=c-1). - (5) Each owner or operator using a control or recovery device shall keep the following records readily accessible: - (i) Continuous records of the equipment operating parameters specified to be monitored under [§ 63.497(a)](/cfr/40/63.497.md?p=a) or specified by the Administrator in accordance with [§ 63.497(b)](/cfr/40/63.497.md?p=b). For flares, the records specified in [§ 63.508](/cfr/40/63.508.md), if applicable, and table 3 to [subpart G](/cfr/40/subpartG.md) of this part shall be maintained in place of continuous records. - (ii) Records of the daily average value of each continuously monitored parameter for each operating day, except as provided in [paragraphs (d)(5)(ii)(D) through (d)(5)(ii)(F)](#d-5-ii-D..d-5-ii-F) of this section. - (A) The daily average shall be calculated as the average of all values for a monitored parameter recorded during the operating day, except as provided in [paragraph (d)(5)(ii)(B)](#d-5-ii-B) of this section. The average shall cover a 24-hour period if operation is continuous, or the number of hours of operation per operating day if operation is not continuous. - (B) 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 hourly or 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 hourly or daily averages. Records shall be kept of the times and durations of all such periods and any other periods of process or control device operation when monitors are not operating. - (C) The operating day shall be the period defined in the operating permit or the Notification of Compliance Status in § [63.506(e)(5)](/cfr/40/63.506.md?p=e-5) or [(8)](/cfr/40/63.506.md?p=e-8). It may be from midnight to midnight or another 24-hour period. - (D) If all recorded values for a monitored parameter during an operating day are below the maximum, or above the minimum, level established in the Notification of Compliance Status in [§ 63.506(e)(5)](/cfr/40/63.506.md?p=e-5) or in the operating permit, the owner or operator may record that all values were below the maximum or above the minimum level, rather than calculating and recording a daily average for that operating day. - (E) Except as specified in [paragraph (d)(5)(ii)(F)](#d-5-ii-F) of this section, for flares, records of the times and duration of all periods during which the pilot flame is absent, shall be kept rather than daily averages. The records specified in this paragraph are not required during periods when emissions are not routed to the flare. - (F) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n), [paragraph (d)(5)(ii)(E)](#d-5-ii-E) of this section no longer applies and instead the owner or operator of the affected source must keep the records specified in [§ 63.108(m)](/cfr/40/63.108.md?p=m) of [subpart F](/cfr/40/subpartF.md) of this part and [§ 63.508](/cfr/40/63.508.md). - (iii) Except as specified in [paragraph (d)(5)(v)](#d-5-v) of this section, hourly records of whether the flow indicator specified under [§ 63.497(d)(1)](/cfr/40/63.497.md?p=d-1) was operating and whether a diversion was detected at any time during the hour, as well as records of the times of all periods when the vent stream is diverted from the control device or the flow indicator is not operating. - (iv) Except as specified in [paragraph (d)(5)(v)](#d-5-v) of this section, where a seal mechanism is used to comply with [§ 63.497(d)(2)](/cfr/40/63.497.md?p=d-2), hourly records of flow are not required. - (A) For compliance with [§ 63.497(d)(2)](/cfr/40/63.497.md?p=d-2), the owner or operator shall record whether the monthly visual inspection of the seals or closure mechanisms has been done, and shall record instances 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 broken. - (B) [Reserved] - (v) For each flow event from a bypass line subject to the requirements in [§ 63.127(d)](/cfr/40/63.127.md?p=d) of [subpart G](/cfr/40/subpartG.md) of this part for each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=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. - (e) If the back-end process operation is subject to an organic HAP emission limitation in [§ 63.494(a)(4)](/cfr/40/63.494.md?p=a-4), the records specified in [paragraphs (e)(1) through (4)](#e-1..e-4) of this section. - (1) The applicable organic HAP emission limitation determined in accordance with [§ 63.494(a)(4)(i) through (iv)](/cfr/40/63.494.md?p=a-4-i..a-4-iv). - (2) The organic HAP emissions from all back-end process operations for each month, along with documentation of all calculations and other information used in the engineering assessment to estimate these emissions. - (3) **The mass of elastomer product produced each month.** - (4) The total mass of organic HAP emitted for each 12-month period divided by the total mass of elastomer produced during the 12-month period, determined in accordance with [§ 63.495(g)(5)](/cfr/40/63.495.md?p=g-5). - (f) Owners and operators subject to [§ 63.494(a)(7)](/cfr/40/63.494.md?p=a-7), must keep the records specified in paragraphs [(f)(1)](#f-1) and [(2)](#f-2) of this section in addition to those records specified elsewhere in this section. - (1) For back-end process vents in chloroprene service, include all uncontrolled, undiluted chloroprene concentration measurements, and the calculations used to determine the total uncontrolled chloroprene mass emission rate for the sum of all vent gas streams. - (2) The owner or operator must keep records of all periods during which operating values are outside of the applicable operating limits specified in [§ 63.510(b)(4) through (6)](/cfr/40/63.510.md?p=b-4..b-6) when regulated material is being routed to the non-flare control device. The record must specify the operating parameter, the applicable limit, and the highest (for maximum operating limits) or lowest (for minimum operating limits) value recorded during the period. # §63.499. Back-end process provisions—reporting. - (a) The owner or operator of an affected source with back-end process operations shall submit the information required in [paragraphs (a)(1) through (a)(3)](#a-1..a-3) of this section, for each back-end process operation at the affected source, as part of the Notification of Compliance Status specified in [§ 63.506(e)(5)](/cfr/40/63.506.md?p=e-5). - (1) **The type of elastomer product processed in the back-end operation.** - (2) The type of process (solution process, emulsion process, etc.) - (3) If the back-end process operation is subject to a residual organic HAP limitation in [§ 63.494(a)(1) through (3)](/cfr/40/63.494.md?p=a-1..a-3), whether compliance will be achieved by stripping technology, or by control or recovery devices. - (b) Each owner or operator of a back-end process operation using stripping to comply with a residual organic HAP limitation in [§ 63.494(a)(1) through (3)](/cfr/40/63.494.md?p=a-1..a-3), and demonstrating compliance by stripper parameter monitoring, shall submit reports as specified in paragraphs [(b)(1)](#b-1) and [(2)](#b-2) of this section. - (1) As part of the Notification of Compliance Status specified in [§ 63.506(e)(5)](/cfr/40/63.506.md?p=e-5), the owner or operator shall submit the information specified in [§ 63.498(c)(1)](/cfr/40/63.498.md?p=c-1). - (2) For organic HAP content/stripper monitoring parameter re-determinations, and the addition of new grades, the information specified in [§ 63.498(c)(1)](/cfr/40/63.498.md?p=c-1) shall be submitted in the next periodic report specified in [§ 63.506(e)(6)](/cfr/40/63.506.md?p=e-6). - (c) Each owner or operator of an affected source with a back-end process operation control or recovery device that shall comply with a residual organic HAP limitation in [§ 63.494(a)(1) through (3)](/cfr/40/63.494.md?p=a-1..a-3), shall submit the information specified in [paragraphs (c)(1) through (3)](#c-1..c-3) of this section as part of the Notification of Compliance Status specified in [§ 63.506(e)(5)](/cfr/40/63.506.md?p=e-5). - (1) The residual organic HAP content, adjusted for the control or recovery device emission reduction, determined in accordance with [§ 63.496(c)(1)](/cfr/40/63.496.md?p=c-1), for each test run in the compliance determination. - (2) The operating parameter level established in accordance with [§ 63.497(c)](/cfr/40/63.497.md?p=c), along with supporting documentation. - (3) The information specified in [paragraphs (c)(3)(i)](#c-3-i) when using a flare, and the information specified in [paragraph (c)(3)(ii)](#c-3-ii) of this section when using a boiler or process heater. - (i) The flare design (i.e., steam-assisted, air-assisted, or non-assisted); all visible emission readings, heat content determinations, flow rate measurements, and exit velocity determinations made during the compliance determination; and all periods during the compliance determination when the pilot flame is absent. - (ii) A description of the location at which the vent stream is introduced into the boiler or process heater. - (d) Whenever a process change, as defined in [§ 63.496(d)](/cfr/40/63.496.md?p=d), is made that causes the redetermination of the compliance status for the back-end process operations subject to a residual organic HAP limitation in [§ 63.494(a)(1) through (3)](/cfr/40/63.494.md?p=a-1..a-3), the owner or operator shall submit a report within 180 days after the process change, as specified in [§ 63.506(e)(7)(iii)](/cfr/40/63.506.md?p=e-7-iii). The report shall include: - (1) A description of the process change; - (2) The results of the redetermination of the compliance status, determined in accordance with [§ 63.496(b)](/cfr/40/63.496.md?p=b), and recorded in accordance with [§ 63.498(d)(1)](/cfr/40/63.498.md?p=d-1), and - (3) Documentation of the re-establishment of a parameter level for the control or recovery device, defined as either a maximum or minimum operating parameter, that indicates proper operation of the control or recovery device, in accordance with [§ 63.497(c)](/cfr/40/63.497.md?p=c) and recorded in accordance with [§ 63.498(d)(2)](/cfr/40/63.498.md?p=d-2). - (e) If an owner or operator uses a control or recovery device other than those listed in [§ 63.497(a)](/cfr/40/63.497.md?p=a) or requests approval to monitor a parameter other than those specified in [§ 63.497(a)](/cfr/40/63.497.md?p=a), the owner or operator shall submit a description of planned reporting and recordkeeping procedures as required under § [63.506(e)(3)](/cfr/40/63.506.md?p=e-3) or [(e)(8)](/cfr/40/63.506.md?p=e-8). The Administrator will specify appropriate reporting and recordkeeping requirements as part of the review of the Precompliance Report or Operating Permit application. - (f) If the back-end process operation is subject to an organic HAP emission limitation in [§ 63.494(a)(4)](/cfr/40/63.494.md?p=a-4), the owner and operator must submit the information specified in paragraphs [(f)(1)](#f-1) and [(2)](#f-2) of this section. - (1) The applicable organic HAP emission limitation determined in accordance with [§ 63.494(a)(4)(i) through (iv)](/cfr/40/63.494.md?p=a-4-i..a-4-iv), shall be submitted no later than 180 days from the date of publication of the final rule amendments in the Federal Register. - (2) Beginning with the first periodic report required to be submitted by [§ 63.506(e)(6)](/cfr/40/63.506.md?p=e-6) that is at least 13 months after the compliance date, the total mass of organic HAP emitted for each of the rolling 12-month periods in the reporting period divided by the total mass of elastomer produced during the corresponding 12-month period, determined in accordance with [§ 63.495(g)(5)](/cfr/40/63.495.md?p=g-5). - (g) Owners and operators subject to [§ 63.494(a)(7)](/cfr/40/63.494.md?p=a-7), must include in the periodic report, the records for the periods specified in [§ 63.498(f)(2)](/cfr/40/63.498.md?p=f-2). Indicate the start date, start time and duration in hours for each period. # §63.500. Back-end process provisions—carbon disulfide limitations for styrene butadiene rubber by emulsion processes. - (a) Owners or operators of sources subject to this subpart producing styrene butadiene rubber using an emulsion process shall operate the process such that the carbon disulfide concentration in each crumb dryer exhausts shall not exceed 45 ppmv. - (1) The owner or operator shall develop standard operating procedures for the addition of sulfur containing shortstop agents to ensure that the limitation in [paragraph (a)](#a) of this section is maintained. There shall be a standard operating procedure representing the production of every grade of styrene butadiene rubber produced at the affected source using a sulfur containing shortstop agent. - (2) A validation of each standard operating procedure shall be conducted in accordance with [paragraph (c)](#c) of this section, except as provided in [paragraph (b)](#b) of this section, to demonstrate compliance with the limitation in [paragraph (a)](#a) of this section. - (3) The owner or operator shall operate the process in accordance with a validated standard operating procedure at all times when styrene butadiene rubber is being produced using a sulfur containing shortstop agent. If a standard operating procedure is changed, it shall be re-validated. - (4) Records specified in [paragraph (d)](#d) of this section shall be maintained. - (5) Reports shall be submitted in accordance with [paragraph (e)](#e) of this section. - (b) **Crumb dryers that are vented to a combustion device are not subject to the provisions in this section.** - (c) The owner or operator shall validate each standard operating procedure to determine compliance with the limitation in [paragraph (a)](#a) of this section using the testing procedures in [paragraph (c)(1)](#c-1) of this section or engineering assessment, as described in [paragraph (c)(2)](#c-2) of this section. - (1) The owner or operator may choose to conduct a performance test, using the procedures in [paragraphs (c)(1)(i) through (c)(1)(iii)](#c-1-i..c-1-iii) of this section to demonstrate compliance with the carbon disulfide concentration limitation in [paragraph (a)](#a) of this section. One test shall be conducted for each standard operating procedure. - (i) Method 1 or 1A of [40 CFR part 60](/cfr/40/part60.md), appendix A, as required, shall be used for selection of the sampling sites. - (ii) The gas volumetric flow rate shall be determined using Method 2, 2A, 2C, or 2D of [40 CFR part 60](/cfr/40/part60.md), appendix A, as required. - (iii) To determine compliance with the carbon disulfide concentration limit in [paragraph (a)](#a) of this section, the owner or operator shall use Method 18 or Method 25A of appendices A-6 and A-7 to [40 CFR part 60](/cfr/40/part60.md), respectively to measure carbon disulfide. ASTM D6420-18 (incorporated by reference, see [§ 63.14](/cfr/40/63.14.md)) may also be used in lieu of Method 18, if the target compounds are all known and are all listed in [Section 1.1](/cfr/40/1.1.md) of ASTM D6420-18 as measurable; ASTM D6420-18 must not be used for methane and ethane; and ASTM D6420-18 may not be used as a total VOC method. Alternatively, any other method or data that has been validated according to the applicable procedures in Method 301 of appendix A to this part, may be used. The following procedures shall be used to calculate carbon disulfide concentration: - (A) The minimum sampling time for each run shall be 1 hour, in which either an integrated sample or a minimum of four grab samples shall be taken. If grab sampling is used, then the samples shall be taken at approximately equal intervals in time, such as 15 minute intervals during the run. - (B) The concentration of carbon disulfide shall be calculated using Equation 32. - (2) The owner or operator may use engineering assessment to demonstrate compliance with the carbon disulfide concentration limitation in [paragraph (a)](#a) of this section. Engineering assessment includes, but is not limited to, the following: - (i) Previous test results, provided the tests are representative of current operating practices at the process unit. - (ii) Bench-scale or pilot-scale test data representative of the process under representative operating conditions. - (iii) Flow rate and/or carbon disulfide emission rate specified or implied within an applicable permit limit. - (iv) Design analysis based on accepted chemical engineering principles, measurable process parameters, or physical or chemical laws or properties. Examples of analytical methods include, but are not limited to: - (A) Use of material balances, - (B) Estimation of flow rate based on physical equipment design such as pump or blower capacities, and - (C) **Estimation of carbon disulfide concentrations based on saturation conditions.** - (v) All data, assumptions, and procedures used in the engineering assessment shall be documented. - (d) Owners and operators of sources subject to this section shall maintain the records specified in paragraphs [(d)(1)](#d-1) and [(d)(2)](#d-2) of this section. - (1) **Documentation of the results of the testing required by paragraph (c) of this section.** - (2) **A description of the standard operating procedure used during the testing.** This description shall include, at a minimum, an identification of the sulfur containing shortstop agent added to the styrene butadiene rubber prior to the dryers, an identification of the point and time in the process where the sulfur containing shortstop agent is added, and an identification of the amount of sulfur containing shortstop agent added per unit of latex. - (e) Owners and operators shall submit the reports as specified in paragraphs [(e)(1)](#e-1) and [(e)(2)](#e-2) of this section. - (1) As part of the Notification of Compliance Status specified in [§ 63.506(e)(5)](/cfr/40/63.506.md?p=e-5), documentation of the results of the testing required by [paragraph (c)](#c) of this section. - (2) If changes are made in the standard operating procedure used during the compliance test and recorded in accordance with [paragraph (d)(2)](#d-2) of this section, and if those changes have the potential for increasing the concentration of carbon disulfide in the crumb dryer exhaust to above the 45 ppmv limit, the owner or operator shall: - (i) Redetermine compliance using the test procedures in [paragraph (c)](#c) of this section, and - (ii) Submit documentation of the testing results in the next periodic report required by [§ 63.506(e)(6)](/cfr/40/63.506.md?p=e-6). # §63.501. Wastewater provisions. - (a) Except as specified in [paragraphs (c) through (f)](#c..f) of this section, the owner or operator of each affected source shall comply with the requirements of [§§ 63.132 through 63.147](/cfr/40/63.132..63.147.md) for each process wastewater stream originating at an affected source, with the requirements of [§ 63.148](/cfr/40/63.148.md) for leak inspection provisions, and with the requirements of [§ 63.149](/cfr/40/63.149.md) for equipment that is subject to [§ 63.149](/cfr/40/63.149.md), with the differences noted in [paragraphs (a)(1) through (23)](#a-1..a-23) of this section. Further, the owner or operator of each affected source shall comply with the requirements of [§ 63.105(a)](/cfr/40/63.105.md?p=a) for maintenance wastewater, as specified in [paragraph (b)](#b) of this section. - (1) When the determination of equivalence criteria in [§ 63.102(b)](/cfr/40/63.102.md?p=b) is referred to in §§ [63.132](/cfr/40/63.132.md), [63.133](/cfr/40/63.133.md), and [63.137](/cfr/40/63.137.md), the provisions in [§ 63.6(g)](/cfr/40/63.6.md?p=g) shall apply for the purposes of this subpart. - (2) When the storage vessel requirements contained in [§§ 63.119 through 63.123](/cfr/40/63.119..63.123.md) are referred to in [§§ 63.132 through 63.149](/cfr/40/63.132..63.149.md), [§§ 63.119 through 63.123](/cfr/40/63.119..63.123.md) are applicable, with the exception of the differences referred to in [§ 63.484](/cfr/40/63.484.md), for the purposes of this subpart. - (3) Owners and operators of affected sources are not required to comply with the requirements in [§ 63.132(b)(1)](/cfr/40/63.132.md?p=b-1) and [§ 63.132(d)](/cfr/40/63.132.md?p=d). Owners and operators of new affected sources, as defined in this subpart, shall comply with the requirements for existing sources in [§§ 63.132 through 63.149](/cfr/40/63.132..63.149.md), with the exceptions noted in paragraphs [(a)(4)](#a-4), [(a)(10)](#a-10), and [(a)(23)](#a-23) of this section. - (4) When [§ 63.146(a)](/cfr/40/63.146.md?p=a) requires the submission of a request for approval to monitor alternative parameters according to the procedures specified in § [63.151(f)](/cfr/40/63.151.md?p=f) or [(g)](/cfr/40/63.151.md?p=g), owners or operators requesting to monitor alternative parameters shall follow the procedures specified in [§ 63.506(f)](/cfr/40/63.506.md?p=f), for the purposes of this subpart. - (5) When [§ 63.147(d)](/cfr/40/63.147.md?p=d) requires owners or operators to keep records of the daily average value of each continuously monitored parameter for each operating day as specified in [§ 63.152(f)](/cfr/40/63.152.md?p=f), owners and operators shall instead keep records of the daily average value of each continuously monitored parameter as specified in [§ 63.506(d)](/cfr/40/63.506.md?p=d), for the purposes of this subpart. - (6) When [§§ 63.132 through 63.149](/cfr/40/63.132..63.149.md) refer to an “existing source,” the term “existing affected source,” as defined in [§ 63.480(a)(3)](/cfr/40/63.480.md?p=a-3) shall apply, for the purposes of this subpart. - (7) When [§§ 63.132 through 63.149](/cfr/40/63.132..63.149.md) refer to a “new source,” the term “new affected source,” as defined in [§ 63.480(a)(4)](/cfr/40/63.480.md?p=a-4) shall apply, for the purposes of this subpart. - (8) Whenever [§§ 63.132 through 63.149](/cfr/40/63.132..63.149.md) refer to a “chemical manufacturing process unit,” the term “elastomer product process unit,” (or EPPU) as defined in [§ 63.482](/cfr/40/63.482.md), shall apply for the purposes of this subpart. In addition, when [§ 63.149](/cfr/40/63.149.md) refers to “a chemical manufacturing process unit that meets the criteria of [§ 63.100(b)](/cfr/40/63.100.md?p=b) of [subpart F](/cfr/40/subpartF.md) of this part,” the term “an EPPU as defined in [§ 63.482(b)](/cfr/40/63.482.md?p=b)” shall apply for the purposes of this subpart. - (9) When § [63.132(a)](/cfr/40/63.132.md?p=a) and [(b)](/cfr/40/63.132.md?p=b) refer to the “applicable dates specified in [§ 63.100](/cfr/40/63.100.md) of [subpart F](/cfr/40/subpartF.md) of this part,” the compliance dates specified in [§ 63.481](/cfr/40/63.481.md) shall apply, for the purposes of this subpart. - (10) The provisions of [paragraphs (a)(10)(i) through (iv)](#a-10-i..a-10-iv) of this section clarify the organic HAP that an owner or operator must consider when complying with the requirements of [§§ 63.132 through 63.149](/cfr/40/63.132..63.149.md). - (i) Owners and operators are exempt from all requirements in [§§ 63.132 through 63.149](/cfr/40/63.132..63.149.md) that pertain solely and exclusively to organic HAP listed on table 8 to [40 CFR part 63](/cfr/40/part63.md), subpart G. - (ii) When [§§ 63.132 through 63.149](/cfr/40/63.132..63.149.md) refer to table 9 compounds, the owner or operator is only required to consider compounds that meet the definition of organic HAP in [§ 63.482](/cfr/40/63.482.md) and that are listed in table 9 to [40 CFR part 63](/cfr/40/part63.md), [subpart G](/cfr/40/subpartG.md), for the purposes of this subpart. - (iii) When [§§ 63.132 through 63.149](/cfr/40/63.132..63.149.md) refer to compounds in table 36 to [40 CFR part 63](/cfr/40/part63.md), [subpart G](/cfr/40/subpartG.md), or compounds in List 1 and/or List 2, as listed in table 36 to [40 CFR part 63](/cfr/40/part63.md), [subpart G](/cfr/40/subpartG.md), the owner or operator is only required to consider compounds that meet the definition of organic HAP in [§ 63.482](/cfr/40/63.482.md) and that are listed in table 36 to [40 CFR part 63](/cfr/40/part63.md), [subpart G](/cfr/40/subpartG.md), for the purposes of this subpart. - (iv) For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(o)](/cfr/40/63.481.md?p=o), the provisions specified in [§ 63.132(c)(1)(iii)](/cfr/40/63.132.md?p=c-1-iii) do not apply. Instead, if the wastewater stream contains chloroprene such that it is considered to be in chloroprene service, as defined in [§ 63.482](/cfr/40/63.482.md), then the wastewater stream is a Group 1 wastewater stream. For wastewater streams in chloroprene service, owners and operators must also meet the requirements specified in [§ 63.510](/cfr/40/63.510.md). - (11) Whenever [§§ 63.132 through 63.147](/cfr/40/63.132..63.147.md) refer to a Group 1 wastewater stream or a Group 2 wastewater stream, the definitions of these terms contained in [§ 63.482](/cfr/40/63.482.md) shall apply, for the purposes of this subpart. - (12) When [§ 63.149(d)](/cfr/40/63.149.md?p=d) refers to “[§ 63.100(f)](/cfr/40/63.100.md?p=f) of [subpart F](/cfr/40/subpartF.md)” the phrase “[§ 63.480(c)](/cfr/40/63.480.md?p=c)” shall apply for the purposes of this subpart. In addition, where [§ 63.149(d)](/cfr/40/63.149.md?p=d) states “and the item of equipment is not otherwise exempt from controls by the provisions of subparts [A](/cfr/40/subpartA.md), [F](/cfr/40/subpartF.md), G, or H of this part”, the phrase “and the item of equipment is not otherwise exempt from controls by the provisions of subparts [A](/cfr/40/subpartA.md), [F](/cfr/40/subpartF.md), G, H, or U of this part,” shall apply for the purposes of this subpart. - (13) When § [63.149(e)(1)](/cfr/40/63.149.md?p=e-1) and [(e)(2)](/cfr/40/63.149.md?p=e-2) refer to “a chemical manufacturing process unit subject to the new source requirements of 40 CFR [63.100(l)(1)](/cfr/40/63.100.md?p=l-1) or [40](/cfr/40/40.md) CFR 63.100 (l)(2),” the phrase “an EPPU that is part of a new affected source or that is a new affected source,” shall apply for the purposes of this subpart. - (14) When the Notification of Compliance Status requirements contained in [§ 63.152(b)](/cfr/40/63.152.md?p=b) are referred to in §§ [63.138](/cfr/40/63.138.md) and [63.146](/cfr/40/63.146.md), the Notification of Compliance Status requirements contained in [§ 63.506(e)(5)](/cfr/40/63.506.md?p=e-5) shall apply for the purposes of this subpart. In addition, when §§ [63.138](/cfr/40/63.138.md) and [63.146](/cfr/40/63.146.md) require that information be reported according to [§ 63.152(b)](/cfr/40/63.152.md?p=b) in the Notification of Compliance Status, owners or operators of affected sources shall report the specified information in the Notification of Compliance Status required by [§ 63.506(e)(5)](/cfr/40/63.506.md?p=e-5), for the purposes of this subpart. - (15) When the Periodic Report requirements contained in [§ 63.152(c)](/cfr/40/63.152.md?p=c) are referred to in [§ 63.146](/cfr/40/63.146.md), the Periodic Report requirements contained in [§ 63.506(e)(6)](/cfr/40/63.506.md?p=e-6) shall apply for the purposes of this subpart. In addition, when [§ 63.146](/cfr/40/63.146.md) requires that information be reported in the Periodic Reports required in [§ 63.152(c)](/cfr/40/63.152.md?p=c), owners or operators of affected sources shall report the specified information in the Periodic Reports required in [§ 63.506(e)(6)](/cfr/40/63.506.md?p=e-6), for the purposes of this subpart. - (16) When the term “range” is used in [§§ 63.132 through 63.149](/cfr/40/63.132..63.149.md), the term “level” shall apply instead, for the purposes of this subpart. This level shall be determined using the procedures specified in [§ 63.505](/cfr/40/63.505.md). - (17) When [§ 63.143(f)](/cfr/40/63.143.md?p=f) specifies that owners or operators shall establish the range that indicates proper operation of the treatment process or control device, the owner or operator shall instead comply with the requirements of § [63.505(c)](/cfr/40/63.505.md?p=c) or [(d)](/cfr/40/63.505.md?p=d) for establishing parameter level maximums/minimums, for the purposes of this subpart. - (18) When [§ 63.146(b)(7)](/cfr/40/63.146.md?p=b-7) and [§ 63.146(b)(8)](/cfr/40/63.146.md?p=b-8) require that “the information on parameter ranges specified in [§ 63.152(b)(2)](/cfr/40/63.152.md?p=b-2)” be reported in the Notification of Compliance Status, owners and operators of affected sources are instead required to report the information on parameter levels in the Notification of Compliance Status as specified in [§ 63.506(e)(5)(ii)](/cfr/40/63.506.md?p=e-5-ii), for the purposes of this subpart. - (19) For the purposes of this subpart, the owner or operator of an affected source is not required to include process wastewater streams that contain styrene when conducting performance tests for the purposes of calculating the required mass removal (RMR) or the actual mass removal (AMR) under the provisions described in [§ 63.145(f)](/cfr/40/63.145.md?p=f) or [§ 63.145(g)](/cfr/40/63.145.md?p=g). For purposes of this paragraph, a process wastewater stream is considered to contain styrene if the wastewater stream meets the requirements in paragraph [(a)(19)(i)](#a-19-i), [(ii)](#a-19-ii), or [(iii)](#a-19-iii) of this section: - (i) The wastewater stream originates at equipment that produces styrene butadiene rubber by solution; - (ii) The wastewater stream originates at equipment that produces styrene butadiene rubber by emulsion; or - (iii) **The wastewater stream originates at equipment that produces styrene butadiene latex.** - (20) When the provisions of [§ 63.139(c)(1)(ii)](/cfr/40/63.139.md?p=c-1-ii), [§ 63.145(d)(4)](/cfr/40/63.145.md?p=d-4), or [§ 63.145(i)(2)](/cfr/40/63.145.md?p=i-2) specify that Method 18 of appendix A-6 to [40 CFR part 60](/cfr/40/part60.md) must be used, Method 18 or Method 25A of appendices A-6 and A-7 to [40 CFR part 60](/cfr/40/part60.md), respectively, may be used for the purposes of this subpart. ASTM D6420-18 (incorporated by reference, see [§ 63.14](/cfr/40/63.14.md)) may also be used in lieu of Method 18, if the target compounds are all known and are all listed in [Section 1.1](/cfr/40/1.1.md) of ASTM D6420-18 as measurable; ASTM D6420-18 must not be used for methane and ethane; and ASTM D6420-18 may not be used as a total VOC method. The use of Method 25A must conform with the requirements in paragraphs [(a)(20)(i)](#a-20-i) and [(ii)](#a-20-ii) of this section. - (i) The organic HAP used as the calibration gas for Method 25A of appendix A-7 to [40 CFR part 60](/cfr/40/part60.md) must be the single organic HAP representing the largest percent by volume of the emissions. - (ii) The use of Method 25A of appendix A-7 to [40 CFR part 60](/cfr/40/part60.md) is acceptable if the response from the high-level calibration gas is at least 20 times the standard deviation of the response from the zero calibration gas when the instrument is zeroed on the most sensitive scale. - (21) In [§ 63.145(j)](/cfr/40/63.145.md?p=j), instead of the reference to [§ 63.11(b)](/cfr/40/63.11.md?p=b), and instead of [§ 63.145(j)(1)](/cfr/40/63.145.md?p=j-1) and [§ 63.145(j)(2)](/cfr/40/63.145.md?p=j-2), the requirements in [§ 63.504(c)](/cfr/40/63.504.md?p=c) shall apply. - (22) The owner or operator of a facility which receives a Group 1 wastewater stream, or a residual removed from a Group 1 wastewater stream, for treatment pursuant to [§ 63.132(g)](/cfr/40/63.132.md?p=g) is subject to the requirements of [§ 63.132(g)](/cfr/40/63.132.md?p=g) with the differences identified in this section, and is not subject to [subpart DD](/cfr/40/subpartDD.md) of this part, with respect to the received material. - (23) When [§ 63.132(g)](/cfr/40/63.132.md?p=g) refers to “[§§ 63.133 through 63.137](/cfr/40/63.133..63.137.md)” or “[§§ 63.133 through 63.147](/cfr/40/63.133..63.147.md)”, the provisions in this § 63.501 shall apply, for the purposes of this subpart. - (b) Except for those streams exempted by paragraphs [(c)](#c) and [(d)](#d) of this section, the owner or operator of each affected source shall comply with the requirements for maintenance wastewater in [§ 63.105](/cfr/40/63.105.md), except that when [§ 63.105(a)](/cfr/40/63.105.md?p=a) refers to “organic HAPs listed in table 9 to [subpart G](/cfr/40/subpartG.md) of this part,” the owner or operator is only required to consider compounds that meet the definition of organic HAP in [§ 63.482](/cfr/40/63.482.md) and that are listed in table 9 to [subpart G](/cfr/40/subpartG.md) of this part, for the purposes of this subpart. - (c) **The provisions of paragraphs (a) and (b) of this section do not apply to the following—** - (1) **Back-end streams originating from equipment whose only elastomer products are latex products.** - (2) Back-end streams at affected sources that are subject to a residual organic HAP limitation in [§ 63.494(a)(1) through (3)](/cfr/40/63.494.md?p=a-1..a-3) and that are complying with these limitations through the use of stripping technology. - (d) Substitute “For each affected source as described in [§ 63.480](/cfr/40/63.480.md), on and after July 15, 2027,” for each occurrence of “For each source as defined in [§ 63.101](/cfr/40/63.101.md), on and after July 15, 2027,”. - (e) Substitute “For each affected source as described in [§ 63.480](/cfr/40/63.480.md), beginning no later than the compliance dates specified in [§ 63.481(n)](/cfr/40/63.481.md?p=n),” for each occurrence of “For each source as defined in [§ 63.101](/cfr/40/63.101.md), beginning no later than the compliance dates specified in [§ 63.100(k)(10)](/cfr/40/63.100.md?p=k-10),”. - (f) Substitute “[§ 63.508](/cfr/40/63.508.md)” for each occurrence of “[§ 63.108](/cfr/40/63.108.md)”.