# 40 CFR § 63.1257 - Test methods and compliance procedures.

(a) General. Except as specified in paragraph (a)(5) of this section, the procedures specified in paragraphs (c), (d), (e), and (f) of this section are required to demonstrate initial compliance with §§ 63.1253, 63.1254, 63.1256, and 63.1252(e), respectively. The provisions in paragraphs (a)(2) and (3) apply to performance tests that are specified in paragraphs (c), (d), and (e) of this section. The provisions in paragraph (a)(5) of this section are used to demonstrate initial compliance with the alternative standards specified in §§ 63.1253(d) and 63.1254(c). The provisions in paragraph (a)(6) of this section are used to comply with the outlet concentration requirements specified in §§ 63.1253(c), 63.1254(a)(2)(i), and (a)(3)(ii)(B), 63.1254(b)(i), and 63.1256(h)(2). Performance tests shall be conducted under such conditions representative of performance of the affected source for the period being tested. Upon request, the owner or operator shall make available to the Administrator such records as may be necessary to determine the conditions of performance tests.

(1) Design evaluation. To demonstrate that a control device meets the required control efficiency, a design evaluation must address the composition and organic HAP concentration of the vent stream entering the control device. A design evaluation also must address other vent stream characteristics and control device operating parameters as specified in any one of paragraphs (a)(1) (i) through (vi) of this section, depending on the type of control device that is used. If the vent stream is not the only inlet to the control device, the efficiency demonstration also must consider all other vapors, gases, and liquids, other than fuels, received by the control device.

(i) For an enclosed combustion device used to comply with the provisions of 63.1253 (b)(2) or (c)(2), or 63.1256(h)(2)(i)(C) with a minimum residence time of 0.5 seconds and a minimum temperature of 760 °C, the design evaluation must document that these conditions exist.

(ii) For a combustion control device that does not satisfy the criteria in paragraph (a)(1)(i) of this section, the design evaluation must document control efficiency and address the following characteristics, depending on the type of control device:

(A) For a thermal vapor incinerator, the design evaluation must consider the autoignition temperature of the organic HAP, must consider the vent stream flow rate, and must establish the design minimum and average temperature in the combustion zone and the combustion zone residence time.

(B) For a catalytic vapor incinerator, the design evaluation shall consider the vent stream flow rate and shall establish the design minimum and average temperatures across the catalyst bed inlet and outlet.

(C) For a boiler or process heater, the design evaluation shall consider the vent stream flow rate; shall establish the design minimum and average flame zone temperatures and combustion zone residence time; and shall describe the method and location where the vent stream is introduced into the flame zone.

(iii) For a condenser, the design evaluation shall consider the vent stream flow rate, relative humidity, and temperature and shall establish the design outlet organic HAP compound concentration level, design average temperature of the condenser exhaust vent stream, and the design average temperatures of the coolant fluid at the condenser inlet and outlet. The temperature of the gas stream exiting the condenser must be measured and used to establish the outlet organic HAP concentration.

(iv) For a carbon adsorption system that regenerates the carbon bed directly onsite in the control device such as a fixed-bed adsorber, the design evaluation shall consider the vent stream flow rate, relative humidity, and temperature and shall establish the design exhaust vent stream organic compound concentration level, adsorption cycle time, number and capacity of carbon beds, type and working capacity of activated carbon used for carbon beds, design total regeneration stream mass or volumetric flow over the period of each complete carbon bed regeneration cycle, design carbon bed temperature after regeneration, design carbon bed regeneration time, and design service life of carbon. For vacuum desorption, the pressure drop shall be included.

(v) For a carbon adsorption system that does not regenerate the carbon bed directly onsite in the control device such as a carbon canister, the design evaluation shall consider the vent stream mass or volumetric flow rate, relative humidity, and temperature and shall establish the design exhaust vent stream organic compound concentration level, capacity of carbon bed, type and working capacity of activated carbon used for carbon bed, and design carbon replacement interval based on the total carbon working capacity of the control device and source operating schedule.

(vi) For a scrubber, the design evaluation shall consider the vent stream composition; constituent concentrations; liquid-to-vapor ratio; scrubbing liquid flow rate and concentration; temperature; and the reaction kinetics of the constituents with the scrubbing liquid. The design evaluation shall establish the design exhaust vent stream organic compound concentration level and will include the additional information in paragraphs (a)(1)(vi)(A) and (B) of this section for trays and a packed column scrubber.

(A) Type and total number of theoretical and actual trays;

(B) Type and total surface area of packing for entire column, and for individual packed sections if column contains more than one packed section.

(2) Calculation of TOC or total organic HAP concentration. The TOC concentration or total organic HAP concentration is the sum of the concentrations of the individual components. If compliance is being determined based on TOC, the owner or operator shall compute TOC for each run using Equation 6 of this subpart. If compliance with the wastewater provisions is being determined based on total organic HAP, the owner or operator shall compute total organic HAP using Equation 6 of this subpart, except that only the organic HAP compounds shall be summed; when determining compliance with paragraph (e)(3)(i) of this section, only the soluble and partially soluble HAP compounds shall be summed.

${\mathrm{CG}}_{T}=\frac{1}{m}\sum _{j=1}^{m}\left(\sum _{i=1}^{n}{\mathrm{CGS}}_{i,j}\right)\phantom{\rule{0ex}{0ex}}\text{(Eq. 6)}\text{}$

where:
CGT = total concentration of TOC in vented gas stream, average of samples, dry basis, ppmv
CGSi, j = concentration of sample components in vented gas stream for sample j, dry basis, ppmv
i = identifier for a compound
n = number of components in the sample
j = identifier for a sample
m = number of samples in the sample run

(3) Outlet concentration correction for supplemental gases -

(i) Combustion devices. Except as provided in § 63.1258(b)(5)(ii)(A), for a combustion device used to comply with an outlet concentration standard, the actual TOC, organic HAP, and hydrogen halide and halogen must be corrected to 3 percent oxygen if supplemental gases, as defined in § 63.1251, are added to the vent stream or manifold. The integrated sampling and analysis procedures of Method 3B of 40 CFR part 60, appendix A, shall be used to determine the actual oxygen concentration (%O2d). The samples shall be taken during the same time that the TOC or total organic HAP or hydrogen halides and halogen samples are taken. The concentration corrected to 3 percent oxygen (Cd) shall be computed using Equation 7A of this subpart:

${C}_{c}-{C}_{m}\left(\frac{17.9}{20.9-%{O}_{2d}}\right)\phantom{\rule{0ex}{0ex}}\text{(Eq. 7A)}$

Where:
Cc = concentration of TOC or total organic HAP or hydrogen halide and halogen corrected to 3 percent oxygen, dry basis, ppmv
Cm = total concentration of TOC or total organic HAP or hydrogen halide and halogen in vented gas stream, average of samples, dry basis, ppmv
%O2d = concentration of oxygen measured in vented gas stream, dry basis, percent by volume

(ii) Noncombustion devices. Except as provided in § 63.1258(b)(5)(ii)(B), if a control device other than a combustion device is used to comply with a TOC, organic HAP, or hydrogen halide outlet concentration standard, the owner or operator must correct the actual concentration for supplemental gases using Equation 7B of this subpart; process knowledge and representative operating data may be used to determine the fraction of the total flow due to supplemental gas.

${C}_{a}={C}_{m}\left(\frac{{V}_{s}+{V}_{a}}{{V}_{a}}\right)\phantom{\rule{0ex}{0ex}}\text{(Eq. 7B)}$

Where:
Ca = corrected outlet TOC, organic HAP, and hydrogen halides and halogens concentration, dry basis, ppmv
Cm = actual TOC, organic HAP, and hydrogen halides and halogens concentration measured at control device outlet, dry basis, ppmv
Va = total volumetric flow rate of all gas streams vented to the control device, except supplemental gases
Vs = total volumetric flow rate of supplemental gases

(4) Exemptions from compliance demonstrations. An owner or operator using any control device specified in paragraphs (a)(4)(i) through (iv) of this section is exempt from the initial compliance provisions in paragraphs (c), (d), and (e) of this section.

(i) A boiler or process heater with a design heat input capacity of 44 megawatts or greater.

(ii) A boiler or process heater into which the emission stream is introduced with the primary fuel.

(iii) 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 and complies with the requirements of 40 CFR part 266, subpart H, or

(B) Has certified compliance with the interim status requirements of 40 CFR part 266, subpart H.

(iv) A hazardous waste incinerator for which the owner or operator has been issued a final permit under 40 CFR part 270 and complies with the requirements of 40 CFR part 264, subpart O, or has certified compliance with the interim status requirements of 40 CFR part 265, subpart O.

(5) Initial compliance with alternative standard. Initial compliance with the alternative standards in §§ 63.1253(d) and 63.1254(c) for combustion devices is demonstrated when the outlet TOC concentration is 20 ppmv or less, and the outlet hydrogen halide and halogen concentration is 20 ppmv or less. Initial compliance with the alternative standards in §§ 63.1253(d) and 63.1254(c) for noncombustion devices is demonstrated when the outlet TOC concentration is 50 ppmv or less, and the outlet hydrogen halide and hydrogen concentration is 50 ppmv or less. To demonstrate initial compliance, the owner or operator shall be in compliance with the monitoring provisions in § 63.1258(b)(5) on the initial compliance date. The owner or operator shall use Method 18 to determine the predominant organic HAP in the emission stream if the TOC monitor is calibrated on the predominant HAP.

(6) Initial compliance with the 20 ppmv outlet limit. Initial compliance with the 20 ppmv TOC and hydrogen halide and halogen concentration is demonstrated when the outlet TOC concentration is 20 ppmv or less, and the outlet hydrogen halide and halogen concentration is 20 ppmv or less. To demonstrate initial compliance, the operator shall use test methods described in paragraph (b) of this section. The owner or operator shall comply with the monitoring provisions in § 63.1258(b)(1) through (4) on the initial compliance date.

(b) Test methods. When testing is conducted to measure emissions from an affected source, the test methods specified in paragraphs (b)(1) through (10) of this section shall be used.

(1) EPA Method 1 or 1A of appendix A of part 60 is used for sample and velocity traverses.

(2) EPA Method 2, 2A, 2C, or 2D of appendix A of part 60 is used for velocity and volumetric flow rates.

(3) EPA Method 3 of appendix A of part 60 is used for gas analysis.

(4) EPA Method 4 of appendix A of part 60 is used for stack gas moisture.

(5) [Reserved]

(6) The following methods are specified for concentration measurements:

(i) Method 18 may be used to determine HAP concentration in any control device efficiency determination.

(ii) Method 25 of appendix A of part 60 may be used to determine total gaseous nonmethane organic concentration for control efficiency determinations in combustion devices.

(iii) Method 26 or 26A of appendix A of part 60 shall be used to determine hydrogen chloride, hydrogen halide and halogen concentrations in control device efficiency determinations or in the 20 ppmv outlet hydrogen halide concentration standard.

(iv) Method 25A of appendix A of part 60 may be used to determine the HAP or TOC concentration for control device efficiency determinations under the conditions specified in Method 25 of appendix A for direct measurement of an effluent with a flame ionization detector, or in demonstrating compliance with the 20 ppmv TOC outlet standard. If Method 25A is used to determine the concentration of TOC for the 20 ppmv standard, the instrument shall be calibrated on methane or the predominant HAP. If calibrating on the predominant HAP, the use of Method 25A shall comply with paragraphs (b)(6)(iv)(A) through (C) of this section.

(A) The organic HAP used as the calibration gas for Method 25A, 40 CFR part 60, appendix A, shall be the single organic HAP representing the largest percent by volume.

(B) The use of Method 25A, 40 CFR part 60, appendix A, 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.

(C) The span value of the analyzer must be less than 100 ppmv.

(7) Testing conditions for continuous processes. Testing of emissions on equipment operating as part of a continuous process will consist of three l-hour runs. Gas stream volumetric flow rates shall be measured every 15 minutes during each 1-hour run. The HAP concentration shall be determined from samples collected in an integrated sample over the duration of each l-hour test run, or from grab samples collected simultaneously with the flow rate measurements (every 15 minutes). If an integrated sample is collected for laboratory analysis, the sampling rate shall be adjusted proportionally to reflect variations in flow rate. For continuous gas streams, the emission rate used to determine compliance shall be the average emission rate of the three test runs.

(8) Testing and compliance determination conditions for batch processes. Testing of emissions on equipment where the flow of gaseous emissions is intermittent (batch operations) shall be conducted as specified in paragraphs (b)(8)(i) through (iii) of this section.

(i) Except as provided in paragraph (b)(9) of this section for condensers, testing shall be conducted at absolute worst-case conditions or hypothetical worst-case conditions. Gas stream volumetric flow rates shall be measured at 15-minute intervals. The HAP or TOC concentration shall be determined from samples collected in an integrated sample over the duration of the test, or from grab samples collected simultaneously with the flow rate measurements (every 15 minutes). If an integrated sample is collected for laboratory analysis, the sampling rate shall be adjusted proportionally to reflect variations in flow rate. The absolute worst-case or hypothetical worst-case conditions shall be characterized by the criteria presented in paragraphs (b)(8)(i)(A) and (B)of this section. In all cases, a site-specific plan shall be submitted to the Administrator for approval prior to testing in accordance with § 63.7(c) and § 63.1260(l). The test plan shall include the emission profile described in paragraph (b)(8)(ii) of this section.

(A) Absolute worst-case conditions are defined by the criteria presented in paragraph (b)(8)(i)(A)(1) or (2) of this section if the maximum load is the most challenging condition for the control device. Otherwise, absolute worst-case conditions are defined by the conditions in paragraph (b)(8)(i)(A)(3) of this section. The owner or operator must consider all relevant factors, including load and compound-specific characteristics in defining absolute worst-case conditions.

(1) The period in which the inlet to the control device will contain at least 50 percent of the maximum HAP load (in lb) capable of being vented to the control device over any 8 hour period. An emission profile as described in paragraph (b)(8)(ii)(A) of this section shall be used to identify the 8-hour period that includes the maximum projected HAP load.

(2) A 1-hour period of time in which the inlet to the control device will contain the highest HAP mass loading rate, in lb/hr, capable of being vented to the control device. An emission profile as described in paragraph (b)(8)(ii)(A) of this section shall be used to identify the 1-hour period of maximum HAP loading.

(3) The period of time when the HAP loading or stream composition (including non-HAP) is most challenging for the control device. These conditions include, but are not limited to the following:

(i) Periods when the stream contains the highest combined VOC and HAP load, in lb/hr, described by the emission profiles in paragraph (b)(8)(ii) of this section;

(ii) Periods when the streams contain HAP constituents that approach limits of solubility for scrubbing media;

(iii) Periods when the streams contain HAP constituents that approach limits of adsorptivity for carbon adsorption systems.

(B) Hypothetical worst-case conditions are simulated test conditions that, at a minimum, contain the highest hourly HAP load of emissions that would be predicted to be vented to the control device from the emissions profile described in paragraph (b)(8)(ii)(B) or (C) of this section.

(ii) Emissions profile. The owner or operator may choose to perform tests only during those periods of the worst-case conditions that the owner or operator selects to control as part of achieving the required emission reduction. The owner or operator must develop an emission profile for the vent to the control device that describes the characteristics of the vent stream at the inlet to the control device under worst case conditions. The emission profile shall be developed based on any one of the procedures described in (b)(8)(ii)(A) through (C) of this section, as required by paragraph (b)(8)(i).

(A) Emission profile by process. The emission profile must consider all emission episodes that could contribute to the vent stack for a period of time that is sufficient to include all processes venting to the stack and shall consider production scheduling. The profile shall describe the HAP load to the device that equals the highest sum of emissions from the episodes that can vent to the control device in any given hour. Emissions per episode shall be calculated using the procedures specified in paragraph (d)(2) of this section. Emissions per episode shall be divided by the duration of the episode only if the duration of the episode is longer than 1 hour.

(B) Emission profile by equipment. The emission profile must consist of emissions that meet or exceed the highest emissions, in lb/hr, that would be expected under actual processing conditions. The profile shall describe equipment configurations used to generate the emission events, volatility of materials processed in the equipment, and the rationale used to identify and characterize the emission events. The emissions may be based on using a compound more volatile than compounds actually used in the process(es), and the emissions may be generated from all equipment in the process(es) or only selected equipment.

(C) Emission profile by capture and control device limitation. The emission profile shall consider the capture and control system limitations and the highest emissions, in lb/hr, that can be routed to the control device, based on maximum flowrate and concentrations possible because of limitations on conveyance and control equipment (e.g., fans, LEL alarms and safety bypasses).

(iii) Three runs, at a minimum of 1 hour each and a maximum of 8 hours each, are required for performance testing. Each run must occur over the same worst-case conditions, as defined in paragraph (b)(8)(i) of this section.

(9) Testing requirements for condensers. For emission streams controlled using condensers, continuous direct measurement of condenser outlet gas temperature to be used in determining concentrations per the design evaluation described in § 63.1257(a)(1)(iii) is required.

(10) Wastewater testing. Wastewater analysis shall be conducted in accordance with paragraph (b)(10)(i), (ii), (iii), (iv), or (v) of this section.

(i) Method 305. Use procedures specified in Method 305 of 40 CFR part 63, appendix A, and comply with requirements specified in paragraph (b)(10)(vi) of this section.

(ii) EPA Method 624, 625, 1624, 1625, 1666, or 1671. Use procedures specified in EPA Method 624, 625, 1624, 1625, 1666, or 1671 of 40 CFR part 136, appendix A, and comply with requirements in paragraph (b)(10)(vi) of this section.

(iii) Method 8260 or 8270. Use procedures specified in Method 8260 or 8270 in “Test Methods for Evaluating Solid Waste, Physical/Chemical Methods,” EPA Publication No. SW-846, Third Edition, September 1986, as amended by Update I, November 15, 1992. As an alternative, an owner or operator may use any more recent, updated version of Method 8260 or 8270 approved by the EPA. For the purpose of using Method 8260 or 8270 to comply with this subpart, the owner or operator must maintain a formal quality assurance program consistent with either Section 8 of Method 8260 or Method 8270, and this program must include the following elements related to measuring the concentrations of volatile compounds:

(A) Documentation of site-specific procedures to minimize the loss of compounds due to volatilization, biodegradation, reaction, or sorption during the sample collection, storage, and preparation steps.

(B) Documentation of specific quality assurance procedures followed during sampling, sample preparation, sample introduction, and analysis.

(C) Measurement of the average accuracy and precision of the specific procedures, including field duplicates and field spiking of the material source before or during sampling with compounds having similar chemical characteristics to the target analytes.

(iv) Other EPA methods. Use procedures specified in the method, validate the method using the procedures in paragraph (b)(10)(iv)(A) or (B) of this section, and comply with the procedures in paragraph (b)(10)(vi) of this section.

(A) Validate the method according to section 5.1 or 5.3 of Method 301 of 40 CFR part 63, appendix A.

(B) Follow the procedure as specified in “Alternative Validation Procedure for EPA Waste Methods” 40 CFR part 63, appendix D.

(v) Methods other than an EPA method. Use procedures specified in the method, validate the method using the procedures in paragraph (b)(10)(iv)(A) of this section, and comply with the requirements in paragraph (b)(10)(vi) of this section.

(vi) Sampling plan. The owner or operator shall prepare a sampling plan. Wastewater samples shall be collected using sampling procedures which minimize loss of organic compounds during sample collection and analysis and maintain sample integrity. The sample plan shall include procedures for determining recovery efficiency of the relevant partially soluble and soluble HAP compounds. An example of an acceptable sampling plan would be one that incorporates similar sampling and sample handling requirements to those of Method 25D of 40 CFR part 60, appendix A. The sampling plan shall be maintained at the facility.

(c) Initial compliance with storage tank provisions. The owner or operator of an affected storage tank shall demonstrate initial compliance with § 63.1253(b) or (c), as applicable, by fulfilling the requirements of paragraph (c)(1),or (c)(2), or (c)(3) of this section.

(1) Performance test. If this option is chosen to demonstrate initial compliance with the percent reduction requirement of § 63.1253(b)(1) or (c)(1)(i), the efficiency of the control device shall be calculated using performance test data as specified in paragraphs (c)(1)(i) through (iii) of this section. To demonstrate initial compliance with the outlet concentration requirements in § 63.1253(b)(2) and (c)(2), the owner or operator must conduct a performance test and fulfill the requirements of paragraph (a)(6) of this section.

(i) Equations 8 and 9 of this subpart shall be used to calculate the mass rate of total HAP reasonably expected maximum filling rate at the inlet and outlet of the control device for standard conditions of 20 °C: where:

${E}_{i}={K}_{2}\left(\sum _{j=1}^{n}{C}_{\mathrm{ij}}{M}_{\mathrm{ij}}\right){Q}_{i}\phantom{\rule{0ex}{0ex}}\text{(Eq. 8)}$

${E}_{o}={K}_{2}\left(\sum _{j=1}^{n}{C}_{\mathrm{oj}}{M}_{\mathrm{oj}}\right){Q}_{o}\phantom{\rule{0ex}{0ex}}\text{(Eq. 9)}$

where:
Cij, Coj = concentration of sample component j of the gas stream at the inlet and outlet of the control device, respectively, dry basis, ppmv
Ei, Eo = mass rate of total HAP at the inlet and outlet of the control device, respectively, dry basis, kg/hr
Mij, Moj = molecular weight of sample component j of the gas stream at the inlet and outlet of the control device, respectively, gram/gram-mole
Qi, Qo = flow rate of gas stream at the inlet and outlet of the control device, respectively, dry standard cubic meter per minute
K2 = constant, 2.494 × 10−6 (parts per million) −1 (gram-mole per standard cubic meter) (kilogram/gram) (minute/hour), where standard temperature is 20 °C
n = number of sample components in the gas stream

(ii) The percent reduction in total HAP shall be calculated using Equation 10 of this subpart:

$R=\frac{{E}_{i}-{E}_{o}}{{E}_{i}}\left(100\right)\phantom{\rule{0ex}{0ex}}\text{(Eq. 10)}$

where:
R = control efficiency of control device, percent
Ei = mass rate of total HAP at the inlet to the control device as calculated under paragraph (c)(1)(i) of this section, kilograms organic HAP per hour
Eo = mass rate of total HAP at the outlet of the control device, as calculated under paragraph (c)(1)(i) of this section, kilograms organic HAP per hour

(iii) A performance test is not required to be conducted if the control device used to comply with § 63.1253 (storage tank provisions) is also used to comply with § 63.1254 (process vent provisions), and compliance with § 63.1254 has been demonstrated in accordance with paragraph (d) of this section.

(2) Design evaluation. If this option is chosen to demonstrate initial compliance with the percent reduction requirement of § 63.1253(b) or (c), a design evaluation shall be prepared in accordance with the provisions in paragraph (a)(1) of this section. The design evaluation shall include documentation demonstrating that the control device being used achieves the required control efficiency during reasonably expected maximum filling rate.

(3) Floating roof. If the owner or operator of an affected source chooses to comply with the provisions of § 63.1253(b) or (c) by installing a floating roof, the owner or operator shall comply with the procedures described in §§ 63.119(b), (c), (d), and 63.120(a), (b), and (c), with the differences noted in paragraphs (c)(3)(i) through (v) of this section for the purposes of this subpart.

(i) When the term “storage vessel” is used in §§ 63.119 and 63.120, the definition of “storage tank” in § 63.1251 shall apply for the purposes of this subpart.

(ii) When December 31, 1992 is referred to in § 63.119, April 2, 1997 shall apply instead for the purposes of this subpart.

(iii) When April 22, 1994 is referred to in § 63.119, September 21, 1998 shall apply instead for the purposes of this subpart.

(iv) When the phrase “the compliance date specified in § 63.100 of subpart F of this part” is referred to in § 63.120, the phrase “the compliance date specified in § 63.1250” shall apply for the purposes of this subpart.

(v) When the phrase “the maximum true vapor pressure of the total organic HAP's in the stored liquid falls below the values defining Group 1 storage vessels specified in table 5 or table 6 of this subpart” is referred to in § 63.120(b)(1)(iv), the phrase “the maximum true vapor pressure of the total organic HAP in the stored liquid falls below 13.1 kPa” shall apply for the purposes of this subpart.

(4) Initial compliance with alternative standard. Initial compliance with § 63.1253(d) is demonstrated by fulfilling the requirements of paragraph (a)(5) of this section.

(5) Planned maintenance. The owner or operator shall demonstrate compliance with the requirements of § 63.1253(e) by including the periods of planned routine maintenance specified by date and time in each Periodic Report required by § 63.1260.

(d) Initial compliance with process vent provisions. An owner or operator of an affected source complying with the process vent standards in § 63.1254 shall demonstrate compliance using the procedures described in paragraphs (d)(1) through (4) of this section.

(1) Except as provided in paragraph (a)(4) of this section, initial compliance with the process vent standards in § 63.1254 shall be demonstrated using the procedures specified in paragraphs (d)(1)(i) through (iv), as applicable.

(i) Initial compliance with § 63.1254(a)(2)(i) is demonstrated when the actual emissions of HAP from the sum of all process vents within a process is less than or equal to 900 kg/yr. Initial compliance with § 63.1254(a)(2)(ii) is demonstrated when the actual emissions of HAP from the sum of all process vents in compliance with § 63.1254(a)(2)(i) is less than or equal to 1,800 kg/yr. Uncontrolled HAP emissions and controlled HAP emissions shall be determined using the procedures described in paragraphs (d)(2) and (3) of this section. Controlled emissions during periods of planned routine maintenance of a CCCD as specified in § 63.1252(h), must be calculated assuming the HAP emissions are reduced by 93 percent.

(ii) Initial compliance with the percent reduction requirements in § 63.1254(a)(1)(i), (a)(3), and (b) is demonstrated by:

(A) Determining controlled HAP emissions using the procedures described in paragraph (d)(3) of this section, and uncontrolled HAP emissions determined using the procedures described in paragraph (d)(2) of this section, and demonstrating that the reductions required by § 63.1254(a)(1)(i), (a)(3), and (b) are met; or

(B) Controlling the process vents using a device meeting the criteria specified in paragraph (a)(4) of this section.

(iii) Initial compliance with the outlet concentration requirements in § 63.1254(a)(1)(ii)(A), (a)(3), and (b)(1) is demonstrated when the outlet TOC concentration is 20 ppmv or less and the outlet hydrogen halide and halogen concentration is 20 ppmv or less. The owner or operator shall demonstrate compliance by fulfilling the requirements in paragraph (a)(6) of this section.

(iv) Initial compliance with § 63.1254(c) is demonstrated by fulfilling the requirements of paragraph (a)(5) of this section.

(2) Uncontrolled emissions. An owner or operator of an affected source complying with the emission limitation required by § 63.1254(a)(1), or emissions reductions specified in § 63.1254(a)(2), (a)(3), or (b), for each process vent within a process, shall calculate uncontrolled emissions from all equipment in the process according to the procedures described in paragraph (d)(2)(i) or (ii) of this section, as appropriate.

(i) Emission estimation procedures. Owners or operators shall determine uncontrolled emissions of HAP using measurements and/or calculations for each batch emission episode within each unit operation according to the engineering evaluation methodology in paragraphs (d)(2)(i)(A) through (H) of this section. Except where variations are noted, individual HAP partial pressures in multicomponent systems shall be determined by the following methods: If the components are miscible in one another, use Raoult's law to calculate the partial pressures; if the solution is a dilute aqueous mixture, use Henry's law to calculate partial pressures; if Raoult's law or Henry's law are not appropriate or available, use experimentally obtained activity coefficients or models such as the group-contribution models, to predict activity coefficients, or 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. Chemical property data can be obtained from standard reference texts.

(A) Vapor displacement. Emissions from vapor displacement due to transfer of material shall be calculated using Equation 11 of this subpart. The individual HAP partial pressures may be calculated using Raoult's law.

$E=\frac{\left(V\right)}{\left(R\right)\left(T\right)}×\sum _{i=1}^{n}\left({P}_{i}\right)\left({\mathrm{MW}}_{i}\right)\phantom{\rule{0ex}{0ex}}\text{(Eq. 11)}$

where:
E = mass of HAP emitted
V = volume of gas displaced from the vessel
R = ideal gas law constant
T = temperature of the vessel vapor space; absolute
Pi = partial pressure of the individual HAP
MWi = molecular weight of the individual HAP
n = number of HAP compounds in the emission stream i = identifier for a HAP compound

(B) Purging. Emissions from purging shall be calculated using Equation 12 of this subpart. The partial pressures of individual condensable compounds may be calculated using Raoult's law, the pressure of the vessel vapor space may be set equal to 760 mmHg, and the partial pressure of HAP shall be assumed to be 25 percent of the saturated value if the purge flow rate is greater than 100 standard cubic feet per minute (scfm).

$E=\sum _{i=1}^{n}{P}_{i}{\mathrm{MW}}_{i}×\frac{\left(V\right)\left(t\right)}{\left(R\right)\left(T\right)}×\frac{{P}_{T}}{{P}_{T}-\sum _{j=1}^{m}\left({P}_{j}\right)}\phantom{\rule{0ex}{0ex}}\text{(Eq. 12)}$

Where:
E = mass of HAP emitted
V = purge flow rate at the temperature and pressure of the vessel vapor space
R = ideal gas law constant
T = temperature of the vessel vapor space; absolute
Pi = partial pressure of the individual HAP
Pj = partial pressure of individual condensable VOC compounds (including HAP)
PT = pressure of the vessel vapor space
MWi = molecular weight of the individual HAP
t = time of purge
n = number of HAP compounds in the emission stream
i = identifier for a HAP compound
j = identifier for a condensable compound
m = number of condensable compounds (including HAP) in the emission stream

(C) Heating. Emissions caused by the heating of a vessel to a temperature equal to or lower than 10 K below the boiling point shall be calculated using the procedures in either paragraph (d)(2)(i)(C)(1) or (3) of this section. Emissions caused by heating a vessel to a temperature that is higher than 10 K below the boiling point and less than the boiling point, must be calculated using the procedures in either paragraph (d)(2)(i)(C) (2) or (3) of this section. If the contents of a vessel are heated to the boiling point, emissions must be calculated using the procedures in paragraph (d)(2)(i)(C)(4) of this section.

(1) This paragraph describes procedures to calculate emissions if the final temperature to which the vessel contents are heated is 10 K below the boiling point of the HAP in the vessel, or lower. The owner or operator shall calculate the mass of HAP emitted per episode using either Equation 13 or 14 of this subpart. The moles of noncondensable gas displaced are calculated using Equation 15 of this subpart. The initial and final pressure of the noncondensable gas in the vessel shall be calculated using Equation 16 of this subpart. The average molecular weight of HAP in the displaced gas shall be calculated using Equation 17 of this subpart.

$E=\frac{\sum _{i=1}^{n}\left(\left({P}_{i}*\right)\left({x}_{i}\right)\left({\mathrm{MW}}_{i}\right)\right)}{760-\sum _{j=1}^{m}\left(\left({P}_{j}*\right)\left({x}_{j}\right)\right)}×\mathrm{\Delta \eta }\phantom{\rule{0ex}{0ex}}\text{(Eq. 13)}$

$E=\frac{\frac{\sum _{i=1}^{n}{\left({P}_{i}\right)}_{T1}}{{\mathrm{Pa}}_{1}}+\frac{\sum _{i=1}^{n}{\left({P}_{i}\right)}_{T2}}{{\mathrm{Pa}}_{2}}}{2}×\mathrm{\Delta \eta }×{\mathrm{MW}}_{\mathrm{HAP}}\phantom{\rule{0ex}{0ex}}\text{(Eq. 14)}$

$\mathrm{\Delta \eta }=\frac{V}{R}⌊\left(\frac{{\mathrm{Pa}}_{1}}{{T}_{1}}\right)-\left(\frac{{\mathrm{Pa}}_{2}}{{T}_{2}}\right)⌋\phantom{\rule{0ex}{0ex}}\text{(Eq. 15)}$

${\mathrm{Pa}}_{n}={P}_{\mathrm{atm}}-\sum _{j=1}^{m}{\left({P}_{j}\right)}_{\mathrm{Tn}}\phantom{\rule{0ex}{0ex}}\text{(Eq. 16)}$

${\mathrm{MW}}_{\mathrm{HAP}}=\sum _{i=1}^{n}\frac{\left({\left({P}_{i}\right)}_{{T}_{1}}+{\left({P}_{i}\right)}_{{T}_{2}}\right){\mathrm{MW}}_{i}}{\sum _{i=1}^{n}\left({\left({P}_{i}\right)}_{{T}_{1}}+{\left({P}_{i}\right)}_{{T}_{2}}\right)}\phantom{\rule{0ex}{0ex}}\text{(Eq. 17)}$

Where:
E = mass of HAP vapor displaced from the vessel being heated
xi = mole fraction of each HAP in the liquid phase
xj = mole fraction of each condensable VOC (including HAP) in the liquid phase
Pi* = vapor pressure of each HAP in the vessel headspace at any temperature between the initial and final heatup temperatures, mmHg.
Pj* = vapor pressure of each condensable VOC (including HAP) in the vessel headspace at any temperature between the initial and final heatup temperatures, mmHg.
760 = atmospheric pressure, mmHg
MWHAP = the average molecular weight of HAP present in the displaced gas
Δη = number of moles of noncondensable gas displaced
V = volume of free space in the vessel
R = ideal gas law constant
T1 = initial temperature of vessel contents, absolute
T2 = final temperature of vessel contents, absolute
Pan = partial pressure of noncondensable gas in the vessel headspace at initial (n = 1) and final (n = 2) temperature
Patm = atmospheric pressure (when Δη is used in Equation 13 of this subpart, Patm may be set equal to 760 mmHg for any vessel)
(Pj)Tn = partial pressure of each condensable compound (including HAP) in the vessel headspace at the initial temperature (n = 1) and final (n = 2) temperature
m = number of condensable compounds (including HAP) in the displaced vapor
j = identifier for a condensable compound
(Pi)Tn = partial pressure of each HAP in the vessel headspace at initial (T1) and final (T2) temperature
MWi = molecular weight of the individual HAP
n = number of HAP compounds in the emission stream
i = identifier for a HAP compound

(2) If the vessel contents are heated to a temperature that is higher than 10 K below the boiling point and less than the boiling point, emissions must be calculated using the procedures in paragraph (d)(2)(i)(C)(2)(i), or (ii), or (iii) of this section.

(i) Use Equation 13 of this subpart. In Equation 13 of this subpart, the HAP vapor pressures must be determined at the temperature 10 K below the boiling point. In the calculation of Δη for Equation 13 of this subpart, T2 must be the temperature 10 K below the boiling point, and Pa2 must be determined at the temperature 10 K below the boiling point.

(ii) Use Equation 14 of this subpart. In Equation 14 of this subpart, the HAP partial pressures must be deter mined at the temperature 10 K below the boiling point. In the calculation of Δη for Equation 14 of this subpart, T2 must be the temperature 10 K below the boiling point, and Pa2 must be determined at the temperature 10 K below the boiling point. In the calculation of MWHAP, the HAP partial pressures must be determined at the temperature 10 K below the boiling point.

(iii) Use Equation 14 of this subpart over specific temperature increments. If the initial temperature is lower than 10 K below the boiling point, emissions must be calculated as the sum over two increments; one increment is from the initial temperature to 10 K below the boiling point, and the second is from 10 K below the boiling point to the lower of either the final temperature or the temperature 5 K below the boiling point. If the initial temperature is higher than 10 K below the boiling point, emissions are calculated over one increment from the initial temperature to the lower of either the final temperature or the temperature 5 K below the boiling point.

(3)(i) Emissions caused by heating a vessel are calculated using Equation 18 of this subpart.

$E={\mathrm{MW}}_{\mathrm{HAP}}×\left({N}_{\mathrm{avg}}×1n\phantom{\rule{0ex}{0ex}}\left(\frac{{P}_{T}-\sum _{i=1}^{n}\left({P}_{i,1}\right)}{{P}_{T}-\sum _{i=1}^{n}\left({P}_{i,2}\right)}\right)-\left({n}_{i,2}-{n}_{i,1}\right)\right)\phantom{\rule{0ex}{0ex}}\text{(Eq. 18)}$

Where:
E = mass of HAP vapor displaced from the vessel being heated
Navg = average gas space molar volume during the heating process
PT= total pressure in the vessel
Pi, 1 = partial pressure of the individual HAP compounds at T1
Pi, 2 = partial pressure of the individual HAP compounds at T2
MWHAP = average molecular weight of the HAP compounds
ni, 1 = number of moles of condensable in the vessel headspace at T1
ni, 2 = number of moles of condensable in the vessel headspace at T2
n = number of HAP compounds in the emission stream

(ii) The average gas space molar volume during the heating process is calculated using Equation 19 of this subpart.

${N}_{\mathrm{avg}}=\frac{{\mathrm{VP}}_{T}}{2R}\left(\frac{1}{{T}_{1}}+\frac{1}{{T}_{2}}\right)\phantom{\rule{0ex}{0ex}}\text{(Eq. 19)}$

Where:
Navg = average gas space molar volume during the heating process
V = volume of free space in vessel
PT = total pressure in the vessel
R = ideal gas law constant
T1 = initial temperature of the vessel
T2 = final temperature of the vessel

(iii) The difference in the number of moles of condensable in the vessel headspace between the initial and final temperatures is calculated using Equation 20 of this subpart.

$\left({n}_{i,2}-{n}_{i,1}\right)=\frac{V}{\left(R\right)\left({T}_{2}\right)}\sum _{i=1}^{n}{P}_{i,2}-\frac{V}{\left(R\right)\left({T}_{1}\right)}\sum _{i=1}^{n}{P}_{i,1}\phantom{\rule{0ex}{0ex}}\text{(Eq. 20)}$

Where:
V = volume of free space in vessel
R = ideal gas law constant
T1 = initial temperature in the vessel
T2 = final temperature in the vessel
Pi, 1 = partial pressure of the individual HAP compounds at T1
Pi, 2 = partial pressure of the individual HAP compounds at T2
n = number of HAP compounds in the emission stream

(4) If the vessel contents are heated to the boiling point, emissions must be calculated using the procedure in paragraphs (d)(2)(i)(C)(4)(i) and (ii) of this section.

(i) Use either of the procedures in paragraph (d)(3)(i)(B)(3) of this section to calculate the emissions from heating to the boiling point (note that Pa2 = 0 in the calculation of Δη); and

(ii) While boiling, the vessel must be operated with a properly operated process condenser. An initial demonstration that a process condenser is properly operated is required for some process condensers, as described in paragraph (d)(3)(iii) of this section.

(D) Depressurization. Emissions from depressurization shall be calculated using the procedures in either paragraphs (d)(2)(i)(D)(1) through (4), paragraphs (d)(2)(i)(D)(5) through (9), or paragraph (d)(2)(i)(D)(10) of this section.

(1) Equations 21 and 22 of this subpart are used to calculate the initial and final volumes of noncondensable gas present in the vessel, adjusted to atmospheric pressure. The HAP partial pressures may be calculated using Raoult's law.

${V}_{\mathrm{nc}1}=\frac{{\mathrm{VP}}_{{\mathrm{nc}}_{1}}}{760}\phantom{\rule{0ex}{0ex}}\text{(Eq. 21)}$

${V}_{\mathrm{nc}2}=\frac{{\mathrm{VP}}_{{\mathrm{nc}}_{2}}}{760}\phantom{\rule{0ex}{0ex}}\text{(Eq. 22)}$

Where:
Vnc1 = initial volume of noncondensable gas in the vessel
Vnc2 = final volume of noncondensable gas in the vessel
V = free volume in the vessel being depressurized
Pnc1 = initial partial pressure of the noncondensable gas, as calculated using Equation 23 of this subpart, mmHg
Pnc2 = final partial pressure of the noncondensable gas, as calculated using Equation 24 of this subpart, mmHg
760 = atmospheric pressure, mmHg

(2) The initial and final partial pressures of the noncondensable gas in the vessel are determined using Equations 23 and 24 of this subpart:

${P}_{\mathrm{nc}1}={P}_{1}-\sum _{j=1}^{m}\left({P}_{j}*\right)\left({x}_{j}\right)\phantom{\rule{0ex}{0ex}}\text{(Eq. 23)}$

${P}_{\mathrm{nc}2}={P}_{2}-\sum _{j=1}^{m}\left({P}_{j}*\right)\left({x}_{j}\right)\phantom{\rule{0ex}{0ex}}\text{(Eq. 24)}$

Where:
Pnc1 = initial partial pressure of the noncondensable gas
Pnc2 = final partial pressure of the noncondensable gas
P1 = initial vessel pressure
P2 = final vessel pressure
Pj* = vapor pressure of each condensable (including HAP) in the emission stream
xj = mole fraction of each condensable (including HAP) in the liquid phase
m = number of condensable compounds (including HAP) in the emission stream
j = identifier for a condensable compound

(3) The average ratio of moles of noncondensable to moles of an individual HAP in the emission stream is calculated using Equation 25 of this subpart; this calculation must be repeated for each HAP in the emission stream:

${n}_{\mathrm{Ri}}=\frac{\left(\frac{{P}_{\mathrm{nc}1}}{\left({P}_{i}*\right)\left({x}_{i}\right)}+\frac{{P}_{\mathrm{nc}2}}{\left({P}_{i}*\right)\left({x}_{i}\right)}\right)}{2}\phantom{\rule{0ex}{0ex}}\text{(Eq. 25)}$

Where:
nRi = average ratio of moles of noncondensable to moles of individual HAP
Pnc1 = initial partial pressure of the noncondensable gas, as calculated using Equation 23 of this subpart
Pnc2 = final partial pressure of the noncondensable gas, as calculated using Equation 24 of this subpart
Pi* = vapor pressure of each individual HAP
xi = mole fraction of each individual HAP in the liquid phase.
n = number of HAP compounds
i = identifier for a HAP compound

(4) The mass of HAP emitted shall be calculated using Equation 26 of this subpart:

$E=\left({V}_{\mathrm{nc}1}-{V}_{\mathrm{nc}2}\right)×\frac{{P}_{\mathrm{atm}}}{\mathrm{RT}}×\sum _{i=1}^{n}\frac{{\mathrm{MW}}_{i}}{{n}_{\mathrm{Ri}}}\phantom{\rule{0ex}{0ex}}\text{(Eq. 26)}$

Where:
E = mass of HAP emitted
Vnc1 = initial volume of noncondensable gas in the vessel, as calculated using Equation 21 of this subpart
Vnc2 = final volume of noncondensable gas in the vessel, as calculated using Equation 22 of this subpart
nRi = average ratio of moles of noncondensable to moles of individual HAP, as calculated using Equation 25 of this subpart
Patm = atmospheric pressure, standard
R = ideal gas law constant
T = temperature of the vessel, absolute
MWi = molecular weight of each HAP

(5) The moles of HAP vapor initially in the vessel are calculated using the ideal gas law using Equation 27 of this subpart:

${\eta }_{\mathrm{HAP}}=\frac{\left({Y}_{\mathrm{HAP}}\right)\left(V\right)\left({P}_{1}\right)}{R\phantom{\rule{0ex}{0ex}}T}\phantom{\rule{0ex}{0ex}}\text{(Eq. 27)}$

Where:
YHAP = mole fraction of HAP (the sum of the individual HAP fractions, ΣYi)
V = free volume in the vessel being depressurized
P1 = initial vessel pressure
R = ideal gas law constant
T = vessel temperature, absolute

(6) The initial and final moles of noncondensable gas present in the vessel are calculated using Equations 28 and 29 of this subpart:

${n}_{1}=\frac{{\mathrm{VP}}_{{\mathrm{nc}}_{1}}}{\mathrm{RT}}\phantom{\rule{0ex}{0ex}}\text{(Eq. 28)}$

${n}_{2}=\frac{{\mathrm{VP}}_{{\mathrm{nc}}_{2}}}{\mathrm{RT}}\phantom{\rule{0ex}{0ex}}\text{(Eq. 29)}$

Where:
n1 = initial number of moles of noncondensable gas in the vessel
n2 = final number of moles of noncondensable gas in the vessel
V = free volume in the vessel being depressurized
Pnc1 = initial partial pressure of the noncondensable gas, as calculated using Equation 23 of this subpart
Pnc2 = final partial pressure of the noncondensable gas, as calculated using Equation 24 of this subpart
R = ideal gas law constant
T = temperature, absolute

(7) The initial and final partial pressures of the noncondensable gas in the vessel are determined using Equations 23 and 24 of this subpart.

(8) The moles of HAP emitted during the depressurization are calculated by taking an approximation of the average ratio of moles of HAP to moles of noncondensable and multiplying by the total moles of noncondensables released during the depressurization, using Equation 30 of this subpart:

${n}_{\mathrm{HAP}}=\frac{\left(\frac{{n}_{\mathrm{HAP},1}}{{n}_{1}}+\frac{{n}_{\mathrm{HAP},2}}{{n}_{2}}\right)}{2}\left[{n}_{1}-{n}_{2}\right]\phantom{\rule{0ex}{0ex}}\text{(Eq. 30)}$

where:
nHAP = moles of HAP emitted
n1 = initial number of moles of noncondensable gas in the vessel, as calculated using Equation 28 of this subpart
n2 = final number of moles of noncondensable gas in the vessel, as calculated using Equation 29 of this subpart

(9) The mass of HAP emitted can be calculated using Equation 31 of this subpart:

E=ηHAP * MWHAP (Eq. 31)
where:
E = mass of HAP emitted
ηHAP = moles of HAP emitted, as calculated using Equation 30 of this subpart
MWHAP = average molecular weight of the HAP as calculated using Equation 17 of this subpart

(10) Emissions from depressurization may be calculated using equation 32 of this subpart:

$E=\frac{V}{\left(R\right)\left(T\right)}×1n\left(\frac{{P}_{1}-\sum _{j=1}^{m}\left({P}_{j}\right)}{{P}_{2}-\sum _{j=1}^{m}\left({P}_{j}\right)}\right)×\sum _{i=1}^{n}\left({P}_{i}\right)\left({\mathrm{MW}}_{i}\right)\phantom{\rule{0ex}{0ex}}\text{(Eq. 32)}$

Where:
V = free volume in vessel being depressurized
R = ideal gas law constant
T = temperature of the vessel, absolute
P1 = initial pressure in the vessel
P2 = final pressure in the vessel
Pj = partial pressure of the individual condensable compounds (including HAP)
MWi = molecular weight of the individual HAP compounds
n = number of HAP compounds in the emission stream
m = number of condensable compounds (including HAP) in the emission stream
i = identifier for a HAP compound
j = identifier for a condensable compound.

(E) Vacuum systems. Emissions from vacuum systems may be calculated using Equation 33 of this subpart if the air leakage rate is known or can be approximated. The individual HAP partial pressures may be calculated using Raoult's Law.

$E=\frac{\left(\mathrm{La}\right)\left(t\right)}{{\mathrm{MW}}_{\mathrm{nc}}}\left(\frac{\sum _{i=1}^{n}{P}_{i}{\mathrm{MW}}_{i}}{{P}_{\mathrm{system}}-\sum _{j=1}^{m}{P}_{j}}\right)\phantom{\rule{0ex}{0ex}}\text{(Eq. 33)}$

Where:
E = mass of HAP emitted
Psystem = absolute pressure of receiving vessel or ejector outlet conditions, if there is no receiver
Pi = partial pressure of the HAP at the receiver temperature or the ejector outlet conditions
Pj = partial pressure of condensable (including HAP) at the receiver temperature or the ejector outlet conditions
La = total air leak rate in the system, mass/time
MWnc = molecular weight of noncondensable gas
t = time of vacuum operation
MWi = molecular weight of the individual HAP in the emission stream, with HAP partial pressures calculated at the temperature of the receiver or ejector outlet, as appropriate

(F) Gas evolution. Emissions from gas evolution shall be calculated using Equation 12 of this subpart with V calculated using Equation 34 of this subpart:

$V=\frac{\left({W}_{g}\right)\left(R\right)\left(T\right)}{\left({P}_{T}\right)\left({\mathrm{MW}}_{g}\right)}\phantom{\rule{0ex}{0ex}}\text{(Eq. 34)}$

Where:
V = volumetric flow rate of gas evolution
Wg = mass flow rate of gas evolution
R = ideal gas law constant
T = temperature at the exit, absolute
PT = vessel pressure
MWg = molecular weight of the evolved gas

(G) Air drying. Emissions from air drying shall be calculated using Equation 35 of this subpart:

$E=B×\left(\frac{{\mathrm{PS}}_{1}}{100-{\mathrm{PS}}_{1}}-\frac{{\mathrm{PS}}_{2}}{100-{\mathrm{PS}}_{2}}\right)\phantom{\rule{0ex}{0ex}}\text{(Eq. 35)}$

Where:
E = mass of HAP emitted
B = mass of dry solids
PS1 = HAP in material entering dryer, weight percent
PS2 = HAP in material exiting dryer, weight percent

(H) Empty vessel purging. Emissions from empty vessel purging shall be calculated using Equation 36 of this subpart (Note: The term e-Ft/v can be assumed to be 0):

$E=\left(\frac{V}{\mathrm{RT}}×\left(\sum _{i=1}^{n}\left({P}_{i}\right)\left({\mathrm{MW}}_{i}\right)\right)\left(1-{e}^{-\mathrm{Ft}/v}\right)\right)\phantom{\rule{0ex}{0ex}}\text{(Eq. 36)}$

Where:
V = volume of empty vessel
R = ideal gas law constant
T = temperature of the vessel vapor space; absolute
Pi = partial pressure of the individual HAP at the beginning of the purge
(MWi) = molecular weight of the individual HAP
F = flowrate of the purge gas
t = duration of the purge
n = number of HAP compounds in the emission stream
i = identifier for a HAP compound

(ii) Engineering assessments. The owner or operator shall conduct an engineering assessment to calculate uncontrolled HAP emissions for each emission episode that is not due to vapor displacement, purging, heating, depressurization, vacuum operations, gas evolution, or air drying. For emission episodes caused by any of these types of activities, the owner or operator also may calculate uncontrolled HAP emissions based on an engineering assessment if the owner or operator can demonstrate to the Administrator that the methods in paragraph (d)(2)(i) of this section are not appropriate. Modified versions of the engineering evaluation methods in paragraphs (d)(2)(i)(A) through (H) may be used if the owner or operator demonstrates that they have been used to meet other regulatory obligations, and they do not affect applicability assessments or compliance determinations under this subpart GGG. One criterion the owner or operator could use to demonstrate that the methods in paragraph (d)(2)(i) of this section are not appropriate is if previous test data are available that show a greater than 20 percent discrepancy between the test value and the estimated value. An engineering assessment includes, but is not limited to, the following:

(A) Previous test results, provided the tests are representative of current operating practices at the process unit.

(B) Bench-scale or pilot-scale test data representative of the process under representative operating conditions.

(C) Maximum flow rate, HAP emission rate, concentration, or other relevant parameter specified or implied within a permit limit applicable to the 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 based on process stoichiometry to estimate maximum organic HAP concentrations.

(2) Estimation of maximum flow rate based on physical equipment design such as pump or blower capacities.

(3) Estimation of HAP concentrations based on saturation conditions.

(E) All data, assumptions, and procedures used in the engineering assessment shall be documented in accordance with § 63.1260(e). Data or other information supporting a finding that the emissions estimation equations are inappropriate shall be reported in the Precompliance report.

(3) Controlled emissions. An owner or operator shall determine controlled emissions using the procedures in either paragraph (d)(3)(i) or (ii) of this section.

(i) Small control devices. Except for condensers, controlled emissions for each process vent that is controlled using a small control device shall be determined by using the design evaluation described in paragraph (d)(3)(i)(A) of this section, or conducting a performance test in accordance with paragraph (d)(3)(ii) of this section. Whenever a small control device becomes a large control device, the owner or operator must comply with the provisions in paragraph (d)(3)(ii) of this section and submit the test report in the next Periodic report.

(A) Design evaluation. The design evaluation shall include documentation demonstrating that the control device being used achieves the required control efficiency under worst-case conditions, as determined from the emission profile described in § 63.1257(b)(8)(ii). The control efficiency determined from this design evaluation shall be applied to uncontrolled emissions to estimate controlled emissions. The documentation must be conducted in accordance with the provisions in paragraph (a)(1) of this section. The design evaluation shall also include the value(s) and basis for the parameter(s) monitored under § 63.1258.

(B) Emission estimation equations. An owner or operator using a condenser as a control device shall determine controlled emissions using exhaust gas temperature measurements and calculations for each batch emission episode within each unit operation according to the engineering methodology in paragraphs (d)(3)(i)(B)(1) through (8) of this section. Individual HAP partial pressures shall be calculated as specified in paragraph (d)(2)(i) of this section.

(1) Emissions from vapor displacement shall be calculated using Equation 11 of this subpart with T set equal to the temperature of the receiver and the HAP partial pressures determined at the temperature of the receiver.

(2) Emissions from purging shall be calculated using Equation 12 of this subpart with T set equal to the temperature of the receiver and the HAP partial pressures determined at the temperature of the receiver.

(3) Emissions from heating shall be calculated using either Equation 13 of this subpart or Equation 37 of this subpart. In Equation 13, the HAP vapor pressures shall be determined at the temperature of the receiver. In Equations 13 and 37 of this subpart, Δη is equal to the number of moles of noncondensable displaced from the vessel, as calculated using Equation 15 of this subpart. In Equations 13 and 37 of this subpart, the HAP average molecular weight shall be calculated using Equation 17 with the HAP partial pressures determined at the temperature of the receiver.

$E=\mathrm{\Delta \eta }×\frac{\sum _{i=1}^{n}{P}_{i}}{{P}_{T}-\sum _{j=1}^{m}{P}_{j}}×{\mathrm{MW}}_{\mathrm{HAP}}\phantom{\rule{0ex}{0ex}}\text{(Eq.37)}$

Where:
E = mass of HAP emitted
Δη = moles of noncondensable gas displaced
PT = pressure in the receiver
Pi = partial pressure of the individual HAP at the receiver temperature
Pj = partial pressure of the individual condensable (including HAP) at the receiver temperature
n = number of HAP compounds in the emission stream
i = identifier for a HAP compound
MWHAP = the average molecular weight of HAP in vapor exiting the receiver, as calculated using Equation 17 of this subpart
m = number of condensable compounds (including HAP) in the emission stream

(4)(i) Emissions from depressurization shall be calculated using Equation 38 of this subpart.

$E=\left({V}_{\mathrm{nc}1}-{V}_{\mathrm{nc}2}\right)×\frac{\sum _{i=1}^{n}\left({P}_{i}\right)}{{P}_{T}-\sum _{j=1}^{m}\left({P}_{j}\right)}×\frac{{P}_{T}}{\mathrm{RT}}×{\mathrm{MW}}_{\mathrm{HAP}}\phantom{\rule{0ex}{0ex}}\text{(Eq. 38)}$

Where:
E = mass of HAP vapor emitted
Vnc1 = initial volume of noncondensable in the vessel, corrected to the final pressure, as calculated using Equation 39 of this subpart
Vnc2 = final volume of noncondensable in the vessel, as calculated using Equation 40 of this subpart
Pi = partial pressure of each individual HAP at the receiver temperature
Pj = partial pressure of each condensable (including HAP) at the receiver temperature
T = temperature of the receiver
R = ideal gas law constant
MWHAP = the average molecular weight of HAP calculated using Equation 17 of this subpart with partial pressures determined at the receiver temperature
i = identifier for a HAP compound
n = number of HAP compounds in the emission stream
m = number of condensable compounds (including HAP) in the emission stream
j = identifier for a condensable compound

(ii) The initial and final volumes of noncondensable gas present in the vessel, adjusted to the pressure of the receiver, are calculated using Equations 39 and 40 of this subpart.

${V}_{\mathrm{nc}1}=\frac{{\mathrm{VP}}_{{\mathrm{nc}}_{1}}}{{P}_{T}}\phantom{\rule{0ex}{0ex}}\text{(Eq. 39)}$

${V}_{\mathrm{nc}2}=\frac{{\mathrm{VP}}_{{\mathrm{nc}}_{2}}}{{P}_{T}}\phantom{\rule{0ex}{0ex}}\text{(Eq. 40)}$

Where:
Vnc1 = initial volume of noncondensable gas in the vessel
Vnc2 = final volume of noncondensable gas in the vessel
V = free volume in the vessel being depressurized
Pnc1 = initial partial pressure of the noncondensable gas, as calculated using Equation 41 of this subpart
Pnc2 = final partial pressure of the noncondensable gas, as calculated using Equation 42 of this subpart
PT = pressure of the receiver

(iii) Initial and final partial pressures of the noncondensable gas in the vessel are determined using Equations 41 and 42 of this subpart.

${P}_{\mathrm{nc}1}={P}_{1}-\sum _{j=1}^{m}{P}_{j}\phantom{\rule{0ex}{0ex}}\text{(Eq. 41)}$

${P}_{\mathrm{nc}2}={P}_{2}-\sum _{j=1}^{m}{P}_{j}\phantom{\rule{0ex}{0ex}}\text{(Eq. 42)}$

Where:
Pnc1 = initial partial pressure of the noncondensable gas in the vessel
Pnc2 = final partial pressure of the noncondensable gas in the vessel
P1 = initial vessel pressure
P2 = final vessel pressure
Pj = partial pressure of each condensable compound (including HAP) in the vessel
m = number of condensable compounds (including HAP) in the emission stream
j = identifier for a condensable compound

(5) Emissions from vacuum systems shall be calculated using Equation 33 of this subpart.

(6) Emissions from gas evolution shall be calculated using Equation 12 with V calculated using Equation 34 of this subpart, T set equal to the receiver temperature, and the HAP partial pressures determined at the receiver temperature. The term for time, t, in Equation 12 of this subpart is not needed for the purposes of this calculation.

(7) Emissions from air drying shall be calculated using Equation 11 of this subpart with V equal to the air flow rate and Pi determined at the receiver temperature.

(8) Emissions from empty vessel purging shall be calculated using equation 43 of this subpart:

$E=\frac{V}{R}\left(\left(\sum _{i=1}^{n}\frac{{\left({P}_{i}\right)}_{{T}_{1}}\left({\mathrm{MW}}_{i}\right)}{{T}_{1}}\right)\left({-e}^{-\mathrm{Ft}/V}\right)-\left(\sum _{i=1}^{n}\frac{{\left({P}_{i}\right)}_{{T}_{2}}\left({\mathrm{MW}}_{i}\right)}{{T}_{2}}\right)\left(1n\left(\frac{\sum _{i=1}^{n}{\left({P}_{i}\right)}_{{T}_{2}}}{\sum _{i=1}^{n}{\left({P}_{i}\right)}_{{T}_{1}}}\right)+1\right)\right)\phantom{\rule{0ex}{0ex}}\text{(Eq. 43)}$

Where:
V = volume of empty vessel
R = ideal gas law constant
T1 = temperature of the vessel vapor space at beginning of purge
T2 = temperature of the receiver, absolute
(Pi)T1 = partial pressure of the individual HAP at the beginning of the purge
(Pi)T2 = partial pressure of the individual HAP at the receiver temperature
MWi = molecular weight of the individual HAP
F = flowrate of the purge gas
t = duration of the purge
n = number of HAP compounds in the emission stream
i = identifier for a HAP compound

(ii) Large control devices. Except for condensers, controlled emissions for each process vent that is controlled using a large control device shall be determined by applying the control efficiency of the large control device to the estimated uncontrolled emissions. The control efficiency shall be determined by conducting a performance test on the control device as described in paragraphs (d)(3)(ii)(A) through (C) of this section, or by using the results of a previous performance test as described in paragraph (d)(4) of this section. If the control device is intended to control only hydrogen halides and halogens, the owner or operator may assume the control efficiency of organic HAP is zero percent. If the control device is intended to control only organic HAP, the owner or operator may assume the control efficiency for hydrogen halides and halogen is zero percent. Owners and operators are not required to conduct performance tests for devices described in paragraphs (a)(4) and (d)(4) of this section that are large control devices, as defined in § 63.1251.

(A) The performance test shall be conducted by performing emission testing on the inlet and outlet of the control device following the test methods and procedures of § 63.1257(b). Concentrations shall be calculated from the data obtained through emission testing according to the procedures in paragraph (a)(2) of this section.

(B) Performance testing shall be conducted under absolute, or hypothetical worst-case conditions, as defined in paragraphs (b)(8)(i)(A) through (B) of this section.

(C) The owner or operator may elect to conduct more than one performance test on the control device for the purpose of establishing more than one operating condition at which the control device achieves the required control efficiency.

(iii) Initial compliance demonstration for condensers -

(A) Air pollution control devices. During periods in which a condenser functions as an air pollution control device, controlled emissions shall be calculated using the emission estimation equations described in paragraph (d)(3)(i)(B) of this section.

(B) Process condensers. During periods when the condenser is operating as a process condenser, the owner or operator is required to demonstrate that the process condenser is properly operated if the process condenser meets either of the criteria described in paragraphs (d)(3)(iii)(B)(1) and (2) of this section. The owner or operator must either measure the condenser exhaust gas temperature and show it is less than the boiling or bubble point of the substance(s) in the vessel, or perform a material balance around the vessel and condenser to show that at least 99 percent of the material vaporized while boiling is condensed. The initial demonstration shall be conducted for all appropriate operating scenarios and documented in the Notification of Compliance Status report described in § 63.1260(f).

(1) The process condenser is not followed by an air pollution control device; or

(2) The air pollution control device following the process condenser is not a condenser or is not meeting the alternative standard of § 63.1254(c).

(4) An owner or operator is not required to conduct a performance test for the following:

(i) Any control device for which a previous performance test was conducted, provided the test was conducted using the same procedures specified in § 63.1257(b) over conditions typical of the appropriate worst-case, as defined in § 63.1257(b)(8)(i). The results of the previous performance test shall be used to demonstrate compliance.

(e) Compliance with wastewater provisions -

(1) Determining annual average concentration and annual load. To determine the annual average concentration and annual load of partially soluble and/or soluble HAP compounds in a wastewater stream, as required by § 63.1256(a)(1), an owner or operator shall comply with the provisions in paragraphs (e)(1)(i) through (iii) of this section. A wastewater stream is exempt from the requirements of § 63.1256(a)(2) if the owner or operator determines the annual average concentration and annual load are below all of the applicability cutoffs specified in § 63.1256(a)(1)(i)(A) through (D). For annual average concentration, only initial rinses are included. Concentration measurements based on Method 305 shall be adjusted by dividing each concentration by the compound-specific Fm factor listed in Table 8 of this subpart. Concentration measurements based on methods other than Method 305 may not be adjusted by the compound-specific Fm factor listed in Table 8 of this subpart.

(i) Annual average concentration definition.

(A) When complying with § 63.1256(a)(1)(i)(A), the annual average concentration means the total mass of partially soluble HAP compounds occurring in the wastewater stream during the calendar year divided by the total mass of the wastewater stream discharged during the same calendar year.

(B) When complying with § 63.1256(a)(1)(i) (B) or (C), the annual average concentration means the total mass of partially soluble and/or soluble HAP compounds occurring in the wastewater stream during the calendar year divided by the total mass of the wastewater stream discharged during the same calendar year.

(C) When complying with § 63.1256(a)(1)(i)(D), the annual average concentration means the total mass of soluble HAP compounds occurring in the wastewater stream during the calendar year divided by the total mass of the wastewater stream discharged during the same calendar year.

(ii) Determination of annual average concentration. An owner or operator shall determine annual average concentrations of partially soluble and/or soluble HAP compounds in accordance with the provisions specified in paragraph (e)(1)(ii)(A), (B), or (C) of this section. The owner or operator may determine annual average concentrations by process simulation. Data and other information supporting the simulation shall be reported in the Precompliance Report for approval by the Administrator. The annual average concentration shall be determined either at the POD or downstream of the POD with adjustment for concentration changes made according to paragraph (e)(1)(ii)(D) of this section.

(A) Test methods. The concentration of partially soluble HAP, soluble HAP, or total HAP shall be measured using any of the methods described in paragraphs (b)(10)(i) through (iv) of this section.

(B) Knowledge of the wastewater stream. The concentration of partially soluble HAP, soluble HAP, or total HAP shall be calculated based on knowledge of the wastewater stream according to the procedures in paragraphs (e)(1)(ii)(B)(1) and (2) of this section. The owner or operator shall document concentrations in the Notification of Compliance Status report described in § 63.1260(f).

(1) Mass balance. The owner or operator shall calculate the concentrations of HAP compounds in wastewater considering the total quantity of HAP discharged to the water, the amount of water at the POD, and the amounts of water and solvent lost to other mechanisms such as reactions, air emissions, or uptake in product or other processing materials. The quantities of HAP and water shall be based on batch sheets, manufacturing tickets, or FDA bills of materials. In cases where a chemical reaction occurs that generates or consumes HAP, the amount of HAP remaining after a reaction shall be based on stoichometry assuming 100 percent theoretical consumption or yield, as applicable.

(2) Published water solubility data. For single components in water, owners and operators may use the water solubilities published in standard reference texts at the POD temperature to determine maximum HAP concentration.

(C) Bench scale or pilot-scale test data. The concentration of partially soluble HAP, soluble HAP, or total HAP shall be calculated based on bench scale or pilot-scale test data. The owner or operator shall provide sufficient information to demonstrate that the bench-scale or pilot-scale test concentration data are representative of actual HAP concentrations. The owner or operator shall also provide documentation describing the testing protocol, and the means by which sample variability and analytical variability were accounted for in the determination of HAP concentrations. Documentation of the pilot-scale or bench scale analysis shall be provided in the precompliance report.

(D) Adjustment for concentrations determined downstream of the POD. The owner or operator shall make corrections to the annual average concentration when the concentration is determined downstream of the POD at a location where: two or more wastewater streams have been mixed; one or more wastewater streams have been treated; or, losses to the atmosphere have occurred. The owner or operator shall make the adjustments either to the individual data points or to the final annual average concentration.

(iii) Determination of annual load. An owner or operator shall calculate the partially soluble and/or soluble HAP load in a wastewater stream based on the annual average concentration determined in paragraph (e)(1)(ii) (A), (B), or (C) of this section and the total volume of the wastewater stream, based on knowledge of the wastewater stream in accordance with paragraphs (e)(1)(ii)(B) of this section. The owner or operator shall maintain records of the total liters of wastewater discharged per year as specified in § 63.1259(b).

(2) Compliance with treatment unit control provisions -

(i) Performance tests and design evaluations-general. To comply with the control options in § 63.1256(g) (10) or (13), neither a design evaluation nor a performance test is required. For any other nonbiological treatment process, the owner or operator shall conduct either a design evaluation as specified in paragraph (e)(2)(ii) of this section, or a performance test as specified in paragraph (e)(2)(iii) of this section to demonstrate that each nonbiological treatment process used to comply with § 63.1256(g) (8), (9), and/or (12) achieves the conditions specified for compliance. The owner or operator shall demonstrate by the procedures in either paragraph (e)(2) (ii) or (iii) of this section that each closed biological treatment process used to comply with § 63.1256 (g)(8)(ii), (g)(9)(ii), (g)(11), or (g)(12) achieves the conditions specified for compliance. If an open biological treatment unit is used to comply with § 63.1256 (g)(8)(ii), (g)(9)(ii), (g)(11), or (g)(12), the owner or operator shall comply with the performance test requirements in paragraph (e)(2)(iii) of this section.

(ii) Design evaluation. A design evaluation and supporting documentation that addresses the operating characteristics of the treatment process and that is based on operation at a wastewater stream flow rate and a concentration under which it would be most difficult to demonstrate compliance. For closed biological treatment processes, the percent reduction from removal/destruction in the treatment unit and control device shall be determined by a mass balance over the unit. The mass flow rate of soluble and/or partially soluble HAP compounds exiting the treatment process shall be the sum of the mass flow rate of soluble and/or partially soluble HAP compounds in the wastewater stream exiting the biological treatment process and the mass flow rate of the vented gas stream exiting the control device. The mass flow rate entering the treatment process minus the mass flow rate exiting the process determines the actual mass removal. Compounds that meet the requirements specified in paragraph (e)(2)(iii)(A)(4) of this section are not required to be included in the design evaluation; the term “performance test” in paragraph (e)(2)(iii)(A)(4) of this section shall mean “design evaluation” for the purposes of this paragraph.

(iii) Performance tests. Performance tests shall be conducted using test methods and procedures that meet the applicable requirements specified in paragraphs (e)(2)(iii)(A) through (G) of this section.

(A) General. This paragraph specifies the general procedures for performance tests that are conducted to demonstrate compliance of a treatment process with the control requirements specified in § 63.1256(g).

(1) Representative process unit operating conditions. Compliance shall be demonstrated for representative operating conditions. Operations during periods of malfunction and periods of nonoperation shall not constitute representative conditions. The owner or operator shall record the process information that is necessary to document operating conditions during the test.

(2) Representative treatment process operating conditions. Performance tests shall be conducted when the treatment process is operating at a representative inlet flow rate and concentration. If the treatment process will be operating at several different sets of representative operating conditions, the owner or operator shall comply with paragraphs (e)(2)(iii)(A)(2)(i) and (ii) of this section. The owner or operator shall record information that is necessary to document treatment process or control device operating conditions during the test.

(i) Range of operating conditions. If the treatment process will be operated at several different sets of representative operating conditions, performance testing over the entire range is not required. In such cases, the performance test results shall be supplemented with modeling and/or engineering assessments to demonstrate performance over the operating range.

(ii) Consideration of residence time. If concentration and/or flow rate to the treatment process are not relatively constant (i.e., comparison of inlet and outlet data will not be representative of performance), the owner or operator shall consider residence time, when determining concentration and flow rate.

(3) Testing equipment. All testing equipment shall be prepared and installed as specified in the applicable test methods, or as approved by the Administrator.

(4) Compounds not required to be considered in performance tests. Compounds that meet the requirements specified in (e)(2)(iii)(A)(4)(i), (ii), or (iii) of this section are not required to be included in the performance test. Concentration measurements based on Method 305 shall be adjusted by dividing each concentration by the compound-specific Fm factor listed in Table 8 of this subpart. Concentration measurements based on methods other than Method 305 shall not be adjusted by the compound-specific Fm factor listed in Table 8 of this subpart.

(i) Compounds not used or produced by the PMPU; or

(ii) Compounds with concentrations at the POD that are below 1 ppmw; or

(iii) Compounds with concentrations at the POD that are below the lower detection limit where the lower detection limit is greater than 1 ppmw. The method shall be an analytical method for wastewater which has the compound of interest as a target analyte.

(5) Treatment using a series of treatment processes. In all cases where the wastewater provisions in this subpart allow or require the use of a treatment process to comply with emissions limitations, the owner or operator may use multiple treatment processes. The owner or operator complying with the requirements of § 63.1256(g)(7)(i), when wastewater is conveyed by hard-piping, shall comply with either paragraph (e)(2)(iii)(A)(5)(i) or (ii) of this section. The owner or operator complying with the requirements of § 63.1256(g)(7)(ii) shall comply with the requirements of paragraph (e)(2)(iii)(A)(5)(ii) of this section.

(i) The owner or operator shall conduct the performance test across each series of treatment processes. For each series of treatment processes, inlet concentration and flow rate shall be measured either where the wastewater enters the first treatment process in a series of treatment processes, or prior to the first treatment process as specified in paragraph (e)(2)(iii)(A)(6) of this section. For each series of treatment processes, outlet concentration and flow rate shall be measured where the wastewater exits the last treatment process in the series of treatment processes, except when the last treatment process is an open or a closed aerobic biological treatment process demonstrating compliance by using the procedures in paragraphs (e)(2)(iii)(E) or (F) of this section. When the last treatment process is either an open or a closed aerobic biological treatment process demonstrating compliance by using the procedures in paragraphs (e)(2)(iii)(E) or (F) of this section, inlet and outlet concentrations and flow rates shall be measured at the inlet and outlet to the series of treatment processes prior to the biological treatment process and at the inlet to the biological treatment process, except as provided in paragraph (e)(2)(iii)(A)(6)(ii) of this section. The mass flow rate destroyed in the biological treatment process for which compliance is demonstrated using paragraph (e)(2)(iii)(E) or (F) of this section shall be added to the mass flow rate removed or destroyed in the series of treatment units before the biological treatment unit. This sum shall be used to calculate the overall control efficiency.

(ii) The owner or operator shall conduct the performance test across each treatment process in the series of treatment processes. The mass flow rate removed or destroyed by each treatment process shall be added together and the overall control efficiency calculated to determine whether compliance has been demonstrated using paragraphs (e)(2)(iii)(C), (D), (E), (F), or (G) of this section, as applicable. If a biological treatment process is one of the treatment processes in the series of treatment processes, the inlet to the biological treatment process shall be the point at which the wastewater enters the biological treatment process, or the inlet to the equalization tank if all the criteria of paragraph (e)(2)(iii)(A)(6)(ii) of this section are met.

(6) The owner or operator determining the inlet for purposes of demonstrating compliance with paragraph (e)(2)(iii)(E), or (F)of this section may elect to comply with paragraph (e)(2)(iii)(A)(6)(i) or (ii) of this section.

(i) When wastewater is conveyed exclusively by hard-piping from the point of determination to a treatment process that is either the only treatment process or the first in a series of treatment processes (i.e., no treatment processes or other waste management units are used upstream of this treatment process to store, handle, or convey the wastewater), the inlet to the treatment process shall be at any location from the point of determination to where the wastewater stream enters the treatment process. When samples are taken upstream of the treatment process and before wastewater streams have converged, the owner or operator shall ensure that the mass flow rate of all affected wastewater is accounted for when using § 63.1256(g)(8)(ii), (g)(9)(ii) or (g)(12) of this subpart to comply and that the mass flow rate of all wastewater, not just affected wastewater, is accounted for when using § 63.1256(g)(11) to comply, except as provided in paragraph (e)(2)(iii)(A)(4) of this section.

(ii) The owner or operator may consider the inlet to the equalization tank as the inlet to the biological treatment process if the wastewater is conveyed by hard-piping from either the last previous treatment process or the point of determination to the equalization tank; and the wastewater is conveyed from the equalization tank exclusively by hard-piping to the biological treatment process and no treatment processes or other waste management units are used to store, handle, or convey the wastewater between the equalization tank and the biological treatment process; and the equalization tank is equipped with a fixed roof and a closed-vent system that routes emissions to a control device that meets the requirements of § 63.1256(b)(1)(i) through (iv) and § 63.1256(b)(2)(i). The outlet from the series of treatment processes prior to the biological treatment process is the point at which the wastewater exits the last treatment process in the series prior to the equalization tank, if the equalization tank and biological treatment process are part of a series of treatment processes. The owner or operator shall ensure that the mass flow rate of all affected wastewater is accounted for when using § 63.1256(g)(9)(ii) or (12) to comply and that the mass flow rate of all wastewater, not just affected wastewater is accounted for when using § 63.1256(g)(11) to comply, except as provided in paragraph (e)(2)(iii)(A)(4) of this section.

(B) Noncombustion treatment process - concentration limits. This paragraph applies to performance tests that are conducted to demonstrate compliance of a noncombustion treatment process with the ppmw wastewater stream concentration limits at the outlet of the treatment process. This compliance option is specified in § 63.1256(g)(8)(i) and (9)(i). Wastewater samples shall be collected using sampling procedures which minimize loss of organic compounds during sample collection and analysis and maintain sample integrity per paragraph (b)(10)(vi) of this section. Samples shall be collected and analyzed using the procedures specified in paragraphs (b)(10)(i) through (vi) of this section. Samples may be grab samples or composite samples. Samples shall be taken at approximately equally spaced time intervals over a 1-hour period. Each 1-hour period constitutes a run, and the performance test shall consist of a minimum of three runs. Concentration measurements based on methods other than Method 305 may be adjusted by multiplying each concentration by the compound-specific Fm factor listed in Table 8 of this subpart. (For affected wastewater streams that contains both partially soluble and soluble HAP compounds, compliance is demonstrated only if the sum of the concentrations of partially soluble HAP compounds is less than 50 ppmw, and the sum of the concentrations of soluble HAP compounds is less than 520 ppmw.)

(C) Noncombustion, nonbiological treatment process: percent mass removal/destruction option. This paragraph applies to performance tests that are conducted to demonstrate compliance of a noncombustion, nonbiological treatment process with the percent mass removal limits specified in § 63.1256(g)(8)(ii) and (9)(ii) for partially soluble and soluble HAP compounds, respectively. The owner or operator shall comply with the requirements specified in paragraphs (e)(2)(iii)(C)(1) through (5) of this section.

(1) Concentration. The concentration of partially soluble and/or soluble HAP compounds entering and exiting the treatment process shall be determined as provided in this paragraph. Wastewater samples shall be collected using sampling procedures which minimize loss of organic compounds during sample collection and analysis and maintain sample integrity per paragraph (b)(10)(vi) of this section. The method shall be an analytical method for wastewater which has the compound of interest as a target analyte. Samples may be grab samples or composite samples. Samples shall be taken at approximately equally spaced time intervals over a 1-hour period. Each 1-hour period constitutes a run, and the performance test shall consist of a minimum of three runs. Concentration measurements based on Method 305 shall be adjusted by dividing each concentration by the compound-specific Fm factor listed in Table 8 of this subpart. Concentration measurements based on methods other than Method 305 shall not be adjusted by the compound-specific Fm factor listed in Table 8 of this subpart.

(2) Flow rate. The flow rate of the entering and exiting wastewater streams shall be determined using inlet and outlet flow meters, respectively. Where the outlet flow is not greater than the inlet flow, a single flow meter may be used, and may be used at either the inlet or outlet. Flow rate measurements shall be taken at the same time as the concentration measurements.

(3) Calculation of mass flow rate - for noncombustion, nonbiological treatment processes. The mass flow rates of partially soluble and/or soluble HAP compounds entering and exiting the treatment process are calculated using Equations 44 and 45 of this subpart.

${\mathrm{QMW}}_{a}=\frac{\rho }{p*{10}^{6}}\left(\sum _{k=1}^{\rho }\left({Q}_{a,k}*{C}_{T,a,k}\right)\right)\phantom{\rule{0ex}{0ex}}\text{(Eq. 44)}$

${\mathrm{QMW}}_{b}=\frac{\rho }{p*{10}^{6}}\left(\sum _{k=1}^{\rho }\left({Q}_{b,k}*{C}_{T,b,k}\right)\right)\phantom{\rule{0ex}{0ex}}\text{(Eq. 45)}$

Where:
QMWa, QMWb = mass flow rate of partially soluble or soluble HAP compounds, average of all runs, in wastewater entering (QMWa) or exiting (QMWb) the treatment process, kg/hr
ρ = density of the wastewater, kg/m 3
Qa, k, Qbb, k = volumetric flow rate of wastewater entering (Qa, k) or exiting (Qb, k) the treatment process during each run k, m 3/hr
CT, a, k, CT, b, k = total concentration of partially soluble or soluble HAP compounds in wastewater entering (CT, a, k) or exiting (CT, b, k) the treatment process during each run k, ppmw
p = number of runs
k = identifier for a run
10 6 = conversion factor, mg/kg

(4) Percent removal calculation for mass flow rate. The percent mass removal across the treatment process shall be calculated as follows:

$E=\frac{{\mathrm{QMW}}_{a}-{\mathrm{QMW}}_{b}}{{\mathrm{QMW}}_{a}}×100\phantom{\rule{0ex}{0ex}}\text{(Eq. 46)}$

Where:
E = removal or destruction efficiency of the treatment process, percent
QMWa, QMWb = mass flow rate of partially soluble or soluble HAP compounds in wastewater entering (QMWa) and exiting (QMWb) the treatment process, kg/hr (as calculated using Equations 44 and 45 of this subpart)

(5) Compare mass removal efficiency to required efficiency. Compare the mass removal efficiency (calculated in Equation 46 of this subpart) to the required efficiency as specified in § 63.1256(g)(8)(ii) or (9)(ii). If complying with § 63.1256(g)(8)(ii), compliance is demonstrated if the mass removal efficiency is 99 percent or greater. If complying with § 63.1256(g)(9)(ii), compliance is demonstrated if the mass removal efficiency is 90 percent or greater.

(D) Combustion treatment processes: percent mass removal/destruction option. This paragraph applies to performance tests that are conducted to demonstrate compliance of a combustion treatment process with the percent mass destruction limits specified in § 63.1256(g)(8)(ii) for partially soluble HAP compounds, and/or § 63.1256(g)(9)(ii) for soluble HAP compounds. The owner or operator shall comply with the requirements specified in paragraphs (e)(2)(iii)(D)(1) through (8) of this section.

(1) Concentration in wastewater stream entering the combustion treatment process. The concentration of partially soluble and/or soluble HAP compounds entering the treatment process shall be determined as provided in this paragraph. Wastewater samples shall be collected using sampling procedures which minimize loss of organic compounds during sample collection and analysis and maintain sample integrity per paragraph (b)(10)(vi) of this section. The method shall be an analytical method for wastewater which has the compound of interest as a target analyte. Samples may be grab samples or composite samples. Samples shall be taken at approximately equally spaced time intervals over a 1-hour period. Each 1-hour period constitutes a run, and the performance test shall consist of a minimum of three runs. Concentration measurements based on Method 305 of appendix A of this part shall be adjusted by dividing each concentration by the compound-specific Fm factor listed in Table 8 of this subpart. Concentration measurements based on methods other than Method 305 shall not be adjusted by the compound-specific Fm factor listed in Table 8 of this subpart.

(2) Flow rate of wastewater entering the combustion treatment process. The flow rate of the wastewater stream entering the combustion treatment process shall be determined using an inlet flow meter. Flow rate measurements shall be taken at the same time as the concentration measurements.

(3) Calculation of mass flow rate in wastewater stream entering combustion treatment processes. The mass flow rate of partially soluble and/or soluble HAP compounds entering the treatment process is calculated as follows:

${\mathrm{QMW}}_{a}=\frac{\rho }{p*{10}^{6}}\left(\sum _{k=1}^{\rho }\left({Q}_{a,k}*{C}_{T,a,k}\right)\right)\phantom{\rule{0ex}{0ex}}\text{(Eq. 47)}$

Where:
QMWa = mass flow rate of partially soluble or soluble HAP compounds entering the combustion unit, kg/hr
ρ = density of the wastewater stream, kg/m 3
Qa, k = volumetric flow rate of wastewater entering the combustion unit during run k, m 3/hr
CT, a, k = total concentration of partially soluble or soluble HAP compounds in the wastewater stream entering the combustion unit during run k, ppmw
k = identifier for a run
p = number of runs

(4) Concentration in vented gas stream exiting the combustion treatment process. The concentration of partially soluble and/or soluble HAP compounds (or TOC) exiting the combustion treatment process in any vented gas stream shall be determined as provided in this paragraph. Samples may be grab samples or composite samples. Samples shall be taken at approximately equally spaced time intervals over a 1-hour period. Each 1-hour period constitutes a run, and the performance test shall consist of a minimum of three runs. Concentration measurements shall be determined using Method 18 of 40 CFR part 60, appendix A. Alternatively, any other test method validated according to the procedures in Method 301 of appendix A of this part may be used.

(5) Volumetric flow rate of vented gas stream exiting the combustion treatment process. The volumetric flow rate of the vented gas stream exiting the combustion treatment process shall be determined using Method 2, 2A, 2C, or 2D of 40 CFR part 60, appendix A, as appropriate. Volumetric flow rate measurements shall be taken at the same time as the concentration measurements.

(6) Calculation of mass flow rate of vented gas stream exiting combustion treatment processes. The mass flow rate of partially soluble and/or soluble HAP compounds in a vented gas stream exiting the combustion treatment process shall be calculated as follows:

${\mathrm{QMG}}_{b}={K}_{2}*\left(\sum _{i=1}^{n}\left({\mathrm{CG}}_{b,i}*{\mathrm{MW}}_{i}\right)\right)*{\mathrm{QG}}_{b}\phantom{\rule{0ex}{0ex}}\text{(Eq. 48)}$

Where:
QMGb = mass rate of TOC (minus methane and ethane) or total partially soluble and/or soluble HAP, in vented gas stream, exiting (QMGb) the combustion device, dry basis, kg/hr
CGb, i = concentration of TOC (minus methane and ethane) or total partially soluble and/or soluble HAP, in vented gas stream, exiting (CGb, i) the combustion device, dry basis, ppmv
MWi = molecular weight of a component, kilogram/kilogram-mole
QGb = flow rate of gas stream exiting (QGb) the combustion device, dry standard cubic meters per hour
K2 = constant, 41.57 × 10−9 (parts per million)−1 (gram-mole per standard cubic meter) (kilogram/gram), where standard temperature (gram-mole per standard cubic meter) is 20 °C
i = identifier for a compound
n = number of components in the sample

(7) Destruction efficiency calculation. The destruction efficiency of the combustion unit for partially soluble and/or soluble HAP compounds shall be calculated as follows:

$E=\frac{{\mathrm{QMW}}_{a}-{\mathrm{QMG}}_{b}}{{\mathrm{QMW}}_{a}}*100\phantom{\rule{0ex}{0ex}}\text{(Eq. 49)}$

Where:
E = destruction efficiency of partially soluble or soluble HAP compounds for the combustion unit, percent
QMW 2a = mass flow rate of partially soluble or soluble HAP compounds entering the combustion unit, kg/hr
QMGb = mass flow rate of TOC (minus methane and ethane) or partially soluble and/or soluble HAP compounds in vented gas stream exiting the combustion treatment process, kg/hr

(8) Compare mass destruction efficiency to required efficiency. Compare the mass destruction efficiency (calculated in Equation 49 of this subpart) to the required efficiency as specified in § 63.1256(g)(8)(ii) or (g)(9)(ii). If complying with § 63.1256(g)(8)(ii), compliance is demonstrated if the mass destruction efficiency is 99 percent or greater. If complying with § 63.1256(g)(9)(ii), compliance is demonstrated if the mass destruction efficiency is 90 percent or greater.

(E) Open or closed aerobic biological treatment processes: 95-percent mass destruction option. This paragraph applies to performance tests that are conducted for open or closed aerobic biological treatment processes to demonstrate compliance with the 95-percent mass destruction provisions in § 63.1256(g)(11) for partially soluble and/or soluble HAP compounds.

(1) Concentration in wastewater stream. The concentration of partially soluble and/or soluble HAP as provided in this paragraph. Concentration measurements to determine E shall be taken as provided in paragraph (e)(2)(iii)(A)(5) of this section for a series of treatment processes. Wastewater samples shall be collected using sampling procedures which minimize loss of organic compounds during sample collection and analysis and maintain sample integrity per paragraph (b)(10)(vi) of this section. The method shall be an analytical method for wastewater which has the compound of interest as a target analyte. Samples may be grab samples or composite samples. Samples shall be taken at approximately equally spaced time intervals over a 1-hour period. Each 1-hour period constitutes a run, and the performance test shall consist of a minimum of three runs. Concentration measurements based on Method 305 shall be adjusted by dividing each concentration by the compound-specific Fm factor listed in Table 8 of this subpart. Concentration measurements based on methods other than Method 305 shall not be adjusted by the compound-specific Fm factor listed in Table 8 of this subpart.

(2) Flow rate. Flow rate measurements to determine E shall be taken as provided in paragraph (e)(2)(iii)(A)(5) of this section for a series of treatment processes. Flow rate shall be determined using inlet and outlet flow measurement devices. Where the outlet flow is not greater than the inlet flow, a single flow measurement device may be used, and may be used at either the inlet or outlet. Flow rate measurements shall be taken at the same time as the concentration measurements.

(3) Destruction efficiency. The owner or operator shall comply with the provisions in either paragraph (e)(2)(iii)(E)(3)(i) or (ii) of this section. Compliance is demonstrated if the destruction efficiency, E, is equal to or greater than 95 percent.

(i) If the performance test is performed across the open or closed biological treatment system only, compliance is demonstrated if E is equal to Fbio, where E is the destruction efficiency of partially soluble and/or soluble HAP compounds and Fbio is the site-specific fraction of partially soluble and/or soluble HAP compounds biodegraded. Fbio shall be determined as specified in paragraph (e)(2)(iii)(E)(4) of this section and appendix C of subpart G of this part.

(ii) If compliance is being demonstrated in accordance with paragraphs (e)(2)(iii)(A)(5)(i) or (ii) of this section, the removal efficiency shall be calculated using Equation 50 of this subpart. When complying with paragraph (e)(2)(iii)(A)(5)(i) of this section, the series of nonbiological treatment processes comprise one treatment process segment. When complying with paragraph (e)(2)(iii)(A)(5)(ii) of this section, each nonbiological treatment process is a treatment process segment.

$E=\frac{\text{Nonbiotreatment HAP load removal}+\text{Biotreatment HAP load removal}}{\text{Total influent HAP load}}=\frac{\left(\sum _{i=1}^{n}\left({\mathrm{QMW}}_{a,i}-{\mathrm{QMW}}_{b,i}\right)\right)+{\mathrm{QMW}}_{\mathrm{bio}}*{F}_{\mathrm{bio}}}{{\mathrm{QMW}}_{\mathrm{all}}}\text{(Eq. 50)}$

Where:
QMWa, i = the soluble and/or partially soluble HAP load entering a treatment process segment
QMWb, i = the soluble and/or partially soluble HAP load exiting a treatment process segment
n = the number of treatment process segments
i = identifier for a treatment process element
QMWbio = the inlet load of soluble and/or partially soluble HAP to the biological treatment process. The inlet is defined in accordance with paragraph (e)(2)(iii)(A)(6) of this section. If complying with paragraph (e)(2)(iii)(A)(6)(ii) of this section, QMWbio is equal to QMWb, n
Fbio = site-specific fraction of soluble and/or partially soluble HAP compounds biodegraded. Fbio shall be determined as specified in paragraph (e)(2)(iii)(E)(4) of this section and Appendix C of subpart G of this part.
QMWall = the total soluble and/or partially soluble HAP load to be treated.

(4) Site-specific fraction biodegraded (Fbio). The procedures used to determine the compound-specific kinetic parameters for use in calculating Fbio differ for the compounds listed in Tables 2 and 3 of this subpart. An owner or operator shall calculate Fbio as specified in either paragraph (e)(2)(iii)(E)(4)(i) or (ii) of this section.

(i) For biological treatment processes that do not meet the definition for enhanced biological treatment in § 63.1251, the owner or operator shall determine the Fbio for the compounds in Tables 2 and 3 of this subpart using any of the procedures in appendix C to part 63, except procedure 3 (inlet and outlet concentration measurements). (The symbol “Fbio” represents the site-specific fraction of an individual partially soluble or soluble HAP compound that is biodegraded.)

(ii) If the biological treatment process meets the definition of “enhanced biological treatment process” in § 63.1251, the owner or operator shall determine Fbio for the compounds in Table 2 of this subpart using any of the procedures specified in appendix C to part 63. The owner or operator shall calculate Fbio for the compounds in Table 3 of this subpart using the defaults for first order biodegradation rate constants (K1) in Table 9 of this subpart and follow the procedure explained in Form III of appendix C, 40 CFR part 63, or any of the procedures specified in appendix C of 40 CFR part 63.

(F) Open or closed aerobic biological treatment processes: percent removal for partially soluble or soluble HAP compounds. This paragraph applies to the use of performance tests that are conducted for open or closed aerobic biological treatment processes to demonstrate compliance with the percent removal provisions for either partially soluble HAP compounds in § 63.1256(g)(8)(ii) or soluble HAP compounds in § 63.1256(g)(9)(ii) or (g)(12). The owner or operator shall comply with the provisions in paragraph (e)(2)(iii)(E) of this section, except that compliance with § 63.1256(g)(8)(ii) shall be demonstrated when E is equal to or greater than 99 percent, compliance with § 63.1256(g)(9)(ii) shall be demonstrated when E is equal to or greater than 90 percent, and compliance with § 63.1256(g)(12) shall be demonstrated when E is equal to or greater than 99 percent.

(G) Closed biological treatment processes: percent mass removal option. This paragraph applies to the use of performance tests that are conducted for closed biological treatment processes to demonstrate compliance with the percent removal provisions in §§ 63.1256(g)(8)(ii), (g)(9)(ii), (g)(11), or (g)(12). The owner or operator shall comply with the requirements specified in paragraphs (e)(2)(iii)(G) (1) through (4) of this section.

(1) Comply with the procedures specified in paragraphs (e)(2)(iii)(C) (1) through (3) of this section to determine characteristics of the wastewater entering the biological treatment unit, except that the term “partially soluble and/or soluble HAP” shall mean “soluble HAP” for the purposes of this section if the owner or operator is complying with § 63.1256(g)(9)(ii) or (g)(12), and it shall mean “partially soluble HAP” if the owner or operator is complying with § 63.1256(g)(8)(ii).

(2) Comply with the procedures specified in paragraphs (e)(2)(iii)(D) (4) through (6) of this section to determine the characteristics of gas vent streams exiting a control device, with the differences noted in paragraphs (e)(2)(iii)(G)(3) (i) and (ii) of this section.

(i) The term “partially soluble and/or soluble HAP” shall mean “soluble HAP” for the purposes of this section if the owner or operator is complying with § 63.1256(g)(9)(ii) or (g)(12), and it shall mean “partially soluble HAP” if the owner or operator is complying with § 63.1256(g)(8)(ii).

(ii) The term “combustion treatment process” shall mean “control device” for the purposes of this section.

(3) Percent removal/destruction calculation. The percent removal and destruction across the treatment unit and any control device(s) shall be calculated using Equation 51 of this subpart:

$E=\frac{\left({\mathrm{QMW}}_{a}-\left({\mathrm{QMW}}_{b}+{\mathrm{QMG}}_{b}\right)\right)}{{\mathrm{QMW}}_{a}}\phantom{\rule{0ex}{0ex}}\text{(Eq. 51)}$

Where:
E = removal and destruction efficiency of the treatment unit and control device(s), percent
QMWa, QMWb = mass flow rate of partially soluble and/or soluble HAP compounds in wastewater entering (QMWa) and exiting (QMWb) the treatment process, kilograms per hour (as calculated using Equations 44 and 45)
QMGb = mass flow rate of partially soluble and/or soluble HAP compounds in vented gas stream exiting the control device, kg/hr

(4) Compare mass removal/destruction efficiency to required efficiency. Compare the mass removal/destruction efficiency (calculated using Equation 51 of this subpart) to the required efficiency as specified in § 63.1256(g)(8)(ii), (g)(9)(ii), (g)(11), or (g)(12). If complying with § 63.1256(g)(8)(ii), compliance is demonstrated if the mass removal/destruction is 99 percent or greater. If complying with § 63.1256(g)(9)(ii), compliance is demonstrated if the mass removal/destruction efficiency is 90 percent or greater. If complying with § 63.1256(g)(11), compliance is demonstrated if the mass removal/destruction efficiency is 95 percent or greater. If complying with § 63.1256(g)(12), compliance is demonstrated if the mass removal/destruction efficiency is 99 percent or greater.

(3) Compliance with control device provisions. Except as provided in paragraph (e)(3)(iv) of this section, an owner or operator shall demonstrate that each control device or combination of control devices achieves the appropriate conditions specified in § 63.1256(h)(2) by using one or more of the methods specified in paragraphs (e)(3)(i), (ii), or (iii) of this section.

(i) Performance test for control devices other than flares. This paragraph applies to performance tests that are conducted to demonstrate compliance of a control device with the efficiency limits specified in § 63.1256(h)(2). If complying with the 95-percent reduction efficiency requirement, comply with the requirements specified in paragraphs (e)(3)(i) (A) through (J) of this section. If complying with the 20 ppm by volume requirement, comply with the requirements specified in paragraphs (e)(3)(i) (A) through (G) and (e)(3)(i)(J) of this section.

(A) General. The owner or operator shall comply with the general performance test provisions in paragraphs (e)(2)(iii)(A) (1) through (4) of this section, except that the term “treatment unit” shall mean “control device” for the purposes of this section.

(B) Sampling sites. Sampling sites shall be selected using Method 1 or 1A of 40 CFR part 60, appendix A, as appropriate. For determination of compliance with the 95 percent reduction requirement, sampling sites shall be located at the inlet and the outlet of the control device. For determination of compliance with the 20 ppmv limit, the sampling site shall be located at the outlet of the control device.

(C) Concentration in gas stream entering or exiting the control device. The concentration of total organic HAP or TOC in a gas stream shall be determined as provided in this paragraph. Samples may be grab samples or composite samples (i.e., integrated samples). Samples shall be taken at approximately equally spaced time intervals over a 1-hour period. Each 1-hour period constitutes a run, and the performance test shall consist of a minimum of three runs. Concentration measurements shall be determined using Method 18 of 40 CFR part 60, appendix A. Alternatively, any other test method validated according to the procedures in Method 301 of appendix A of this part may be used.

(D) Volumetric flow rate of gas stream entering or exiting the control device. The volumetric flow rate of the gas stream shall be determined using Method 2, 2A, 2C, or 2D of 40 CFR part 60, appendix A, as appropriate. Volumetric flow rate measurements shall be taken at the same time as the concentration measurements.

(E) Calculation of TOC concentration. The owner or operator shall compute TOC in accordance with the procedures in paragraph (a)(2) of this section.

(F) Calculation of total organic HAP concentration. The owner or operator determining compliance based on total organic HAP concentration shall compute the total organic HAP concentration in accordance with the provisions in paragraph (a)(2) of this section.

(G) Requirements for combustion control devices. If the control device is a combustion device, the owner or operator shall correct TOC and organic HAP concentrations to 3 percent oxygen in accordance with the provisions in paragraph (a)(3) of this section, and demonstrate initial compliance with the requirements for halogenated streams in accordance with paragraph (a)(6) of this section.

(H) Mass rate calculation. The mass rate of either TOC (minus methane and ethane) or total organic HAP for each sample run shall be calculated using the following equations. Where the mass rate of TOC is being calculated, all organic compounds (minus methane and ethane) measured by methods specified in paragraph (e)(3)(i)(C) of this section are summed using Equations 52 and 53 of this subpart. Where the mass rate of total organic HAP is being calculated, only soluble and partially soluble HAP compounds shall be summed using Equations 52 and 53.

${\mathrm{QMG}}_{a}={K}_{2}*\left(\sum _{i=1}^{n}\left({\mathrm{CG}}_{a,i}\right)*\left({\mathrm{MW}}_{i}\right)\right)*{\mathrm{QG}}_{a}\phantom{\rule{0ex}{0ex}}\text{(Eq. 52)}$

${\mathrm{QMG}}_{b}={K}_{2}*\left(\sum _{i=1}^{n}\left({\mathrm{CG}}_{b,i}\right)*\left({\mathrm{MW}}_{i}\right)\right)*{\mathrm{QG}}_{b}\phantom{\rule{0ex}{0ex}}\text{(Eq. 53)}$

Where:
CGa, i, CGb, i = concentration of TOC or total organic HAP, in vented gas stream, entering (CGa, i) and exiting (CGb, i) the control device, dry basis, ppmv
QMGa, QMGb = mass rate of TOC or total organic HAP, in vented gas stream, entering (QMGa) and exiting (QMGb) the control device, dry basis, kg/hr
Mwi = molecular weight of a component, kilogram/kilogram-mole
QGa,QGb = flow rate of gas stream entering (QGa) and exiting (QGb) the control device, dry standard cubic meters per hour
K2 = constant, 41.57 × 10−9 (parts per million)−1 (gram-mole per standard cubic meter) (kilogram/gram), where standard temperature (gram-mole per standard cubic meter) is 20 °C
i = identifier for a compound
n = number of components in the sample

(I) Percent reduction calculation. The percent reduction in TOC or total organic HAP for each sample run shall be calculated using Equation 54 of this subpart:

$E=\frac{{\mathrm{QMG}}_{a}-{\mathrm{QMG}}_{b}}{{\mathrm{QMG}}_{a}}*\left(100%\right)\phantom{\rule{0ex}{0ex}}\text{(Eq. 54)}$

Where:
E = destruction efficiency of control device, percent
QMGa,QMGb = mass rate of TOC or total organic HAP, in vented gas stream entering and exiting (QMGb) the control device, dry basis, kilograms per hour

(J) Compare mass destruction efficiency to required efficiency. If complying with the 95-percent reduction efficiency requirement, compliance is demonstrated if the mass destruction efficiency (calculated in Equation 51 of this subpart) is 95 percent or greater. If complying with the 20 ppmv limit, compliance is demonstrated if the outlet TOC concentration is 20 ppmv, or less.

(ii) Design evaluation. A design evaluation conducted in accordance with the provisions in paragraph (a)(1) of this section. Compounds that meet the requirements specified in paragraph (e)(2)(iii)(A)(4) of this section are not required to be included in the design evaluation.

(iii) Compliance demonstration for flares. When a flare is used to comply with § 63.1256(h), the owner or operator shall comply with the flare provisions in § 63.11(b). An owner or operator is not required to conduct a performance test to determine percent emission reduction or outlet organic HAP or TOC concentration when a flare is used.

(iv) Exemptions from compliance demonstrations. An owner or operator using any control device specified in paragraph (a)(4) of this section is exempt from the requirements in paragraphs (e)(3)(i) through (e)(3)(iii) of this section and from the requirements in § 63.6(f).

(f) Pollution prevention alternative standard. The owner or operator shall demonstrate compliance with § 63.1252(e)(2) using the procedures described in paragraph (f)(1) and (f)(3) of this section. The owner or operator shall demonstrate compliance with § 63.1252(e)(3) using the procedures described in paragraphs (f)(2) and (f)(3) of this section.

(1) Compliance is demonstrated when the annual kg/kg factor, calculated according to the procedure in paragraphs (f)(1)(i) and (iii) of this section, is reduced by at least 75 percent as calculated according to the procedure in paragraph (f)(1)(i) and (ii) of this section.

(i) The production-indexed HAP consumption factors shall be calculated by dividing annual consumption of total HAP by the annual production rate, per process. The production-indexed total VOC consumption factor shall be calculated by dividing annual consumption of total VOC by the annual production rate, per process.

(ii) The baseline factor is calculated from yearly production and consumption data for the first 3-year period in which the PMPU was operational, beginning no earlier than the 1987 calendar year, or for a minimum period of 12 months from startup of the process until the present in which the PMPU was operational and data are available, beginning no earlier than the 1987 calendar year.

(iii) The annual factor is calculated on the following bases:

(A) For continuous processes, the annual factor shall be calculated every 30 days for the 12-month period preceding the 30th day (30-day rolling average).

(B) For batch processes, the annual factor shall be calculated either every 10 batches for the 12-month period preceding the 10th batch (10-batch rolling average) or a maximum of once per month, if the number of batches is greater than 10 batches per month. The annual factor shall be calculated every 5 batches if the number of batches is less than 10 for the 12-month period preceding the 10th batch and shall be calculated every year if the number of batches is less than 5 for the 12-month period preceding the 5th batch.

(2) Compliance is demonstrated when the requirements of paragraphs (f)(2)(i) through (iv) of this section are met.

(i) The annual kg/kg factor, calculated according to the procedure in paragraphs (f)(1)(i) and (f)(1)(iii) of this section, is reduced to a value equal to or less than 50 percent of the baseline factor calculated according to the procedure in paragraphs (f)(1)(i) and (ii) of this section.

(ii) The yearly reductions associated with add-on controls that meet the criteria of §§ 63.1252(h)(3)(ii)(A) through (D) must be equal to or greater than the amounts calculated in paragraphs (f)(2)(ii)(A) and (B) of this section:

(A) The mass of HAP calculated using Equation 55 of this subpart:

$M={\left[\mathrm{kg}/\mathrm{kg}\right]}_{b}\left(0.75-{P}_{R}\right)\left({M}_{\mathrm{prod}}\right)\phantom{\rule{0ex}{0ex}}\text{(Eq. 55)}$

Where:
[kg/kg]b = the baseline production-indexed HAP consumption factor, in kg/kg
Mprod = the annual production rate, in kg/yr
M = the annual reduction required by add-on controls, in kg/yr
PR = the fractional reduction in the annual kg/kg factor achieved using pollution prevention where PR is ≥0.5

(B) The mass of VOC calculated using Equation 56 of this subpart:

VOC reduced = (VFbase − VFP − VFannual) × Mprod (Eq. 56)
Where:
VOCreduced = required VOC emission reduction from add-on controls, kg/yr
VFbase = baseline VOC factor, kg VOC emitted/kg production
VFp = reduction in VOC factor achieved by pollution prevention, kg VOC emitted/kg production
VFannual = target annual VOC factor, kg VOC emitted/kg production
Mprod = production rate, kg/yr

(iii) Demonstration that the criteria in § 63.1252(e)(3)(ii)(A) through (D) are met shall be accomplished through a description of the control device and of the material streams entering and exiting the control device.

(iv) The annual reduction achieved by the add-on control shall be quantified using the methods described in § 63.1257(d).

(3) Each owner or operator of a PMPU complying with the P2 standard shall prepare a P2 demonstration summary that shall contain, at a minimum, the following information:

(i) Descriptions of the methodologies and forms used to measure and record daily consumption of HAP compounds reduced as part of the P2 standard.

(ii) Descriptions of the methodologies and forms used to measure and record daily production of products which are included in the P2 standard.

(iii) Supporting documentation for the descriptions provided in paragraphs (f)(3)(i) and (ii) including, but not limited to, operator log sheets and copies of daily, monthly, and annual inventories of materials and products.

(g) Compliance with storage tank provisions by using emissions averaging. An owner or operator with two or more affected storage tanks may demonstrate compliance with § 63.1253, as applicable, by fulfilling the requirements of paragraphs (g)(1) through (4) of this section.

(1) The owner or operator shall develop and submit for approval an Implementation Plan containing all the information required in § 63.1259(e) 6 months prior to the compliance date of the standard. The Administrator shall have 90 days to approve or disapprove the emissions averaging plan after which time the plan shall be considered approved.

(2) The annual mass rate of total organic HAP (ETi, ETo) shall be calculated for each storage tank included in the emissions average using the procedures specified in paragraph (c)(1), (2), or (3) of this section.

(3) Equations 57 and 58 of this subpart shall be used to calculate total HAP emissions for those tanks subject to § 63.1253(b) or (c):

${E}_{\mathrm{Ti}}=\sum _{j=1}^{n}{E}_{\mathrm{ij}}\phantom{\rule{0ex}{0ex}}\text{(Eq. 57)}$

${E}_{\mathrm{To}}=\sum _{j=1}^{n}{E}_{\mathrm{oj}}\phantom{\rule{0ex}{0ex}}\text{(Eq. 58)}$

Where:
Eij = yearly mass rate of total HAP at the inlet of the control device for tank j
Eoj = yearly mass rate of total HAP at the outlet of the control device for tank j
ETi = total yearly uncontrolled HAP emissions
ETo = total yearly actual HAP emissions
n = number of tanks included in the emissions average

(4) The overall percent reduction efficiency shall be calculated as follows:

$R=\frac{{E}_{\mathrm{Ti}}-D\phantom{\rule{0ex}{0ex}}{E}_{\mathrm{To}}}{{E}_{\mathrm{TI}}}\phantom{\rule{0ex}{0ex}}100%\phantom{\rule{0ex}{0ex}}\text{(Eq. 59)}$

Where:
R = overall percent reduction efficiency
D = discount factor = 1.1 for all controlled storage tanks

(h) Compliance with process vent provisions by using emissions averaging. An owner or operator with two or more affected processes complying with § 63.1254 by using emissions averaging shall demonstrate compliance with paragraphs (h)(1), (2) and (3) of this section.

(1) The owner or operator shall develop and submit for approval an Implementation Plan at least 6 months prior to the compliance date of the standard containing all the information required in § 63.1259(e). The Administrator shall have 90 days to approve or disapprove the emissions averaging plan. The plan shall be considered approved if the Administrator either approves the plan in writing, or fails to disapprove the plan in writing. The 90-day period shall begin when the Administrator receives the request. If the request is denied, the owner or operator must still be in compliance with the standard by the compliance date.

(2) Owners or operators shall calculate uncontrolled and controlled emissions of HAP by using the methods specified in paragraph (d)(2) and (3) of this section for each process included in the emissions average.

(3) Equations 60 and 61 of this subpart shall be used to calculate total HAP emissions:

${E}_{\mathrm{TU}}=\sum _{i=1}^{n}{E}_{\mathrm{Ui}}\phantom{\rule{0ex}{0ex}}\text{(Eq. 60)}$

${E}_{\mathrm{TC}}=\sum _{i=1}^{n}{E}_{\mathrm{Ci}}\phantom{\rule{0ex}{0ex}}\text{(Eq. 61)}$

Where:
EUi = yearly uncontrolled emissions from process i.
ECi = yearly actual emissions for process i.
ETU = total yearly uncontrolled emissions.
ETC = total yearly actual emissions.
n = number of processes included in the emissions average.

(4) The overall percent reduction efficiency shall be calculated using Equation 62 of this subpart:

$R=\frac{{E}_{\mathrm{TU}}-D\phantom{\rule{0ex}{0ex}}{E}_{\mathrm{TC}}}{{E}_{\mathrm{TU}}}\phantom{\rule{0ex}{0ex}}\left(100%\right)\phantom{\rule{0ex}{0ex}}\text{(Eq. 62)}$

Where:
R = overall percent reduction efficiency
D = discount factor = 1.1 for all controlled emission points
[63 FR 50326, Sept. 21, 1998, as amended at 65 FR 52609, Aug. 29, 2000; 66 FR 40134, Aug. 2, 2001; 76 FR 22600, Apr. 21, 2011]