# 40 CFR § 63.150 - Emissions averaging provisions.

§ 63.150 Emissions averaging provisions.

(a) This section applies to owners or operators of existing sources who seek to comply with the emission standard in § 63.112(a) of this subpart by using emissions averaging according to § 63.112(f) of this subpart rather than following the provisions of §§ 63.113 through 63.148 of this subpart. Notwithstanding the definition of process vent in § 63.101 and the sampling site designation in § 63.115(a), for purposes of this section the location of a process vent shall be defined, and the characteristics of its gas stream shall be determined, consistent with paragraph (g)(2)(i) of this section.

(b) Unless an operating permit application has been submitted, the owner or operator shall develop and submit for approval an Implementation Plan containing all of the information required in § 63.151(d) of this subpart for all points to be included in an emissions average. The Implementation Plan or operating permit application shall identify all emission points to be included in the emissions average. This must include any Group 1 emission points to which the reference control technology (defined in § 63.111 of this subpart) is not applied and all other emission points being controlled as part of the average.

(c) The following emission points can be used to generate emissions averaging credits, if control was applied after November 15, 1990 and if sufficient information is available to determine the appropriate value of credits for the emission point:

(1) Group 2 emission points.

(2) Group 1 emission points that are controlled by a technology that the Administrator or permitting authority agrees has a higher nominal efficiency than the reference control technology. Information on the nominal efficiencies for such technologies must be submitted and approved as provided in paragraph (i) of this section.

(3) Emission points from which emissions are reduced by pollution prevention measures. Percent reductions for pollution prevention measures shall be determined as specified in paragraph (j) of this section.

(i) For a Group 1 emission point, the pollution prevention measure must reduce emissions more than the reference control technology would have had the reference control technology been applied to the emission point instead of the pollution prevention measure except as provided in paragraph (c)(3)(ii) of this section.

(ii) If a pollution prevention measure is used in conjunction with other controls for a Group 1 emission point, the pollution prevention measure alone does not have to reduce emissions more than the reference control technology, but the combination of the pollution prevention measure and other controls must reduce emissions more than the reference control technology would have had it been applied instead.

(d) The following emission points cannot be used to generate emissions averaging credits:

(1) Emission points already controlled on or before November 15, 1990, unless the level of control is increased after November 15, 1990, in which case credit will be allowed only for the increase in control after November 15, 1990.

(2) Group 1 emission points that are controlled by a reference control technology, unless the reference control technology has been approved for use in a different manner and a higher nominal efficiency has been assigned according to the procedures in paragraph (i) of this section. For example, it is not allowable to claim that an internal floating roof meeting the specifications of § 63.119(b) of this subpart applied to a storage vessel is achieving greater than 95 percent control.

(3) Emission points on shut-down process units. Process units that are shut down cannot be used to generate credits or debits.

(4) Wastewater that is not process wastewater or wastewater streams treated in biological treatment units. These two types of wastewater cannot be used to generate credits or debits. For the purposes of this section, the terms wastewater and wastewater stream are used to mean process wastewater.

(5) Emission points controlled to comply with a State or Federal rule other than this subpart, unless the level of control has been increased after November 15, 1990 above what is required by the other State or Federal rule. Only the control above what is required by the other State or Federal rule will be credited. However, if an emission point has been used to generate emissions averaging credit in an approved emissions average, and the point is subsequently made subject to a State or Federal rule other than this subpart, the point can continue to generate emissions averaging credit for the purpose of complying with the previously approved average.

(e) For all points included in an emissions average, the owner or operator shall:

(1) Calculate and record monthly debits for all Group 1 emission points that are controlled to a level less stringent than the reference control technology for those emission points. Equations in paragraph (g) of this section shall be used to calculate debits.

(2) Calculate and record monthly credits for all Group 1 or Group 2 emission points that are overcontrolled to compensate for the debits. Equations in paragraph (h) of this section shall be used to calculate credits. Emission points and controls that meet the criteria of paragraph (c) of this section may be included in the credit calculation, whereas those described in paragraph (d) of this section shall not be included.

(3) Demonstrate that annual credits calculated according to paragraph (h) of this section are greater than or equal to debits calculated for the same annual compliance period according to paragraph (g) of this section.

(i) The owner or operator may choose to include more than the required number of credit-generating emission points in an average in order to increase the likelihood of being in compliance.

(ii) The initial demonstration in the Implementation Plan or operating permit application that credit-generating emission points will be capable of generating sufficient credits to offset the debits from the debit-generating emission points must be made under representative operating conditions. After the compliance date, actual operating data will be used for all debit and credit calculations.

(4) Demonstrate that debits calculated for a quarterly (3-month) period according to paragraph (g) of this section are not more than 1.30 times the credits for the same period calculated according to paragraph (h) of this section. Compliance for the quarter shall be determined based on the ratio of credits and debits from that quarter, with 30 percent more debits than credits allowed on a quarterly basis.

(5) Record and report quarterly and annual credits and debits in the Periodic Reports as specified in § 63.152(c) of this subpart. Every fourth Periodic Report shall include a certification of compliance with the emissions averaging provisions as required by § 63.152(c)(5)(iv)(B) of this subpart.

(f) Debits and credits shall be calculated in accordance with the methods and procedures specified in paragraphs (g) and (h) of this section, respectively, and shall not include emissions from the following:

(1) More than 20 individual Group 1 or Group 2 emission points. Where pollution prevention measures (as specified in paragraph (j)(1) of this section) are used to control emission points to be included in an emissions average, no more than 25 emission points may be included in the average. For example, if two emission points to be included in an emissions average are controlled by pollution prevention measures, the average may include up to 22 emission points.

(2) Periods of start-up, shutdown, and malfunction as described in the source's start-up, shutdown, and malfunction plan required by § 63.6(e)(3) of subpart A of this part.

(3) Periods of monitoring excursions as defined in § 63.152(c)(2)(ii)(A) of this subpart. For these periods, the calculation of monthly credits and debits shall be adjusted as specified in paragraphs (f)(3)(i) through (f)(3)(iii) of this section.

(i) No credits would be assigned to the credit-generating emission point.

(ii) Maximum debits would be assigned to the debit-generating emission point.

(iii) The owner or operator may demonstrate to the Administrator that full or partial credits or debits should be assigned using the procedures in paragraph (l) of this section.

(g) Debits are generated by the difference between the actual emissions from a Group 1 emission point that is uncontrolled or is controlled to a level less stringent than the reference control technology, and the emissions allowed for the Group 1 emission point. Debits shall be calculated as follows:

(1) The overall equation for calculating source-wide debits is:

$\begin{array}{c}\text{Debits}=\sum _{i=1}^{n}\left({\mathrm{EPV}}_{\mathrm{iACTUAL}}-\left(0.02\right){\mathrm{EPV}}_{\mathrm{iu}}\right)+\sum _{i=1}^{n}\left({\mathrm{ES}}_{\mathrm{iACTUAL}}\\ \phantom{\rule{0ex}{0ex}}\\ -\left(0.05\right){\mathrm{ES}}_{\mathrm{iu}}\right)+\sum _{i=1}^{n}\left({\mathrm{ETR}}_{\mathrm{iACTUAL}}-{\left(0.02\right)\mathrm{ETR}}_{\mathrm{iu}}\right)\\ \phantom{\rule{0ex}{0ex}}\\ +\sum _{i=1}^{n}\left({\mathrm{EWW}}_{\mathrm{iACTUAL}}-{\mathrm{EWW}}_{\mathrm{ic}}\right)\end{array}$

where:
Debits and all terms of the equation are in units of megagrams per month, and
EPViACTUAL = Emissions from each Group 1 process vent i that is uncontrolled or is controlled to a level less stringent than the reference control technology. This is calculated according to paragraph (g)(2) of this section.
(0.02) EPViu = Emissions from each Group 1 vent i if the reference control technology had been applied to the uncontrolled emissions, calculated according to paragraph (g)(2) of this section.
ESiACTUAL = Emissions from each Group 1 storage vessel i that is uncontrolled or is controlled to a level less stringent than the reference control technology. This is calculated according to paragraph (g)(3) of this section.
(0.05) ESiu = Emissions from each Group 1 storage vessel i if the reference control technology had been applied to the uncontrolled emissions, calculated according to paragraph (g)(3) of this section.
ETRiACTUAL = Emissions from each Group 1 transfer rack i that is uncontrolled or is controlled to a level less stringent than the reference control technology. This is calculated according to paragraph (g)(4) of this section.
(0.02) ETRiu = Emissions from each Group 1 transfer rack i if the reference control technology had been applied to the uncontrolled emissions, calculated according to paragraph (g)(4) of this section.
EWWiACTUAL = Emissions from each Group 1 wastewater stream i that is uncontrolled or is controlled to a level less stringent than the reference control technology. This is calculated according to paragraph (g)(5) of this section.
EWWic = Emissions from each Group 1 wastewater stream i if the reference control technology had been applied to the uncontrolled emissions. This is calculated according to paragraph (g)(5) of this section.
n = The number of emission points being included in the emissions average. The value of n is not necessarily the same for process vents, storage vessels, transfer racks, and wastewater.

(2) Emissions from process vents shall be calculated according to paragraphs (g)(2)(i) through (iii) of this section.

(i) The location of a process vent shall be defined, and the characteristics of its gas stream shall be determined at a point that meets the conditions in either paragraph (g)(2)(i)(A) or (B) of this section and the conditions in paragraphs (g)(2)(i)(C) through (E) of this section.

(A) The point is after the final recovery device (if any recovery devices are present).

(B) If a gas stream included in an emissions average is combined with one or more other gas streams after a final recovery device (if any recovery devices are present), then for each gas stream, the point is at a representative point after any final recovery device and as near as feasible to, but before, the point of combination of the gas streams.

(C) The point is before any control device (for process vents, recovery devices shall not be considered control devices).

(D) The point is before discharge to the atmosphere.

(E) The measurement site for determination of the characteristics of the gas stream was selected using Method 1 or 1A of 40 CFR part 60, appendix A.

(ii) The following equation shall be used for each process vent i to calculate EPViu:

${\mathrm{EPV}}_{\mathrm{iu}}=\left(2.494×{10}^{-9}\right)\mathrm{Qh}\left(\sum _{j=1}^{n}{C}_{j}{M}_{j}\right)$

where:
EPViu = Uncontrolled process vent emission rate from process vent i, megagrams per month.
Q = Vent stream flow rate, dry standard cubic meters per minute, measured using Method 2, 2A, 2C, or 2D of part 60, appendix A, as appropriate.
h = Monthly hours of operation during which positive flow is present in the vent, hours per month.
Cj = Concentration, parts per million by volume, dry basis, of organic HAP j as measured by Method 18 of part 60, appendix A.
Mj = Molecular weight of organic HAP j, gram per gram-mole.
n = Number of organic HAP's.

(A) The values of Q, Cj, and Mj shall be determined during a performance test conducted under representative operating conditions. The values of Q, Cj, and Mj shall be established in the Notification of Compliance Status and must be updated as provided in paragraph (g)(2)(ii)(B) of this section.

(B) If there is a change in capacity utilization other than a change in monthly operating hours, or if any other change is made to the process or product recovery equipment or operation such that the previously measured values of Q, Cj, and Mj are no longer representative, a new performance test shall be conducted to determine new representative values of Q, Cj, and Mj. These new values shall be used to calculate debits and credits from the time of the change forward, and the new values shall be reported in the next Periodic Report.

(iii) The following procedures and equations shall be used to calculate EPViACTUAL:

(A) If the vent is not controlled by a control device or pollution prevention measure, EPViACTUAL = EPViu, where EPViu is calculated according to the procedures in paragraphs (g)(2)(i) and (g)(2)(ii) of this section.

(B) If the vent is controlled using a control device or a pollution prevention measure achieving less than 98-percent reduction,

${\mathrm{EPV}}_{\mathrm{iACTUAL}}={\mathrm{EPV}}_{\mathrm{iu}}×\left(1-\frac{\text{Percent reduction}}{100%}\right)$

(1) The percent reduction shall be measured according to the procedures in § 63.116 of this subpart if a combustion control device is used. For a flare meeting the criteria in § 63.116(a) of this subpart, or a boiler or process heater meeting the criteria in § 63.116(b) of this subpart, the percent reduction shall be 98 percent. If a non-combustion control device is used, percent reduction shall be demonstrated by a performance test at the inlet and outlet of the device, or, if testing is not feasible, by a control design evaluation and documented engineering calculations.

(2) For determining debits from Group 1 process vents, recovery devices shall not be considered control devices and cannot be assigned a percent reduction in calculating EPViACTUAL. The sampling site for measurement of uncontrolled emissions is after the final recovery device. However, as provided in § 63.113(a)(3), a Group 1 process vent may add sufficient recovery to raise the TRE index value above 1.0, thereby becoming a Group 2 process vent.

(3) Procedures for calculating the percent reduction of pollution prevention measures are specified in paragraph (j) of this section.

(3) Emissions from storage vessels shall be calculated as follows:

(i) The following equation shall be used for each storage vessel i to calculate ESiu:

${\mathrm{ES}}_{\mathrm{iu}}=\frac{{L}_{B}+{L}_{W}}{12}$

where:
ESiu = Uncontrolled emissions, defined as emissions from a fixed roof vessel having identical dimensions and vessel color as vessel i, megagrams per month.
LB = Breathing loss emissions, megagrams per year, calculated according to paragraph (g)(3)(i)(A) of this section.
LW = Working loss emissions, megagrams per year, calculated according to paragraph (g)(3)(i)(B) of this section.
12 = Constant, months per year.

(A) Breathing loss emissions shall be calculated using the following equation:

${L}_{B}=1.02×{10}^{-5}{M}_{v}\left(\frac{P}{{P}_{A}-P}\right){0.68}_{D}{1.73}_{H}{0.51}_{\mathrm{\Delta T}}{0.50}_{{F}_{p}C\phantom{\rule{0ex}{0ex}}{K}_{C}}$

where:
Mv = Molecular weight of vapor in storage vessel, pound per pound-mole.
PA = Average atmospheric pressure, pounds per square inch absolute.
P = True vapor pressure of the HAP at liquid storage temperature, pounds per square inch absolute. See table 21 of this subpart.
D = Tank diameter, feet.
H = Average vapor space height, feet. Use vessel-specific values or an assumed value of one-half the height.
Δ T = Average ambient diurnal temperature change, °F. A typical value of 20 °F may be used.
Fp = Paint factor, dimensionless, from table 22 of this subpart; use Fp = 1 for vessels located indoors.
C = Adjustment factor for small diameter tanks, dimensionless; use C = 1 for diameter ≥30 feet; use C = 0.0771D − 0.0013D 2 − 0.1334 for diameter <30 feet.
KC = Product factor, dimensionless. Use 1.0 for organic HAP's.

(B) Working losses shall be calculated using the following equation:

LW = 1.089 × 10−8 Mv (P)(V)(N) (KN) (KC)
where:
V = Tank capacity, gallon.
N = Number of turnovers per year.
KN = Turnover factor, dimensionless, and

$\begin{array}{c}{K}_{N}=\frac{180+N}{6N}\phantom{\rule{0ex}{0ex}}\text{for turnovers}>36\\ {K}_{N}=1\text{for turnovers}\le 36.\end{array}$

Mv, P, and KC as defined in paragraph (g)(3)(i)(A) of this section.

(C) The owner or operator may elect to calculate ESiu in accordance with the methods described in American Petroleum Institute Publication 2518, Evaporative Loss from Fixed-Roof Tanks (incorporated by reference as specified in § 63.14 of this part).

(1) The owner or operator who elects to use these alternative methods must use them for all storage vessels included in the emissions average as debit or credit generating points.

(2) The equations of paragraphs (g)(3)(i)(A) and (g)(3)(i)(B) of this section shall not be used in conjunction with the alternative methods provided under paragraph (g)(3)(i)(C) of this section.

(ii) The following procedures and equations shall be used for each fixed roof storage vessel i that is not controlled with a floating roof to calculate ESiACTUAL:

(A) If the vessel is not controlled, ESiACTUAL = ESiu, where ESiu is calculated according to the procedures in paragraph (g)(3)(i) of this section.

(B) Except as provided in paragraph (g)(3)(ii)(C) of this section, if the vessel is controlled using a control device or pollution prevention measure achieving less than 95-percent reduction,

${\mathrm{ES}}_{\mathrm{iACTUAL}}={\mathrm{ES}}_{\mathrm{iu}}*\left(\frac{1-\text{Percent reduction}}{100}\right)$

(1) The percent reduction for a control device shall be determined through a design evaluation according to the procedures specified in § 63.120(d) of this subpart.

(2) Procedures for calculating the percent reduction for pollution prevention measures are specified in paragraph (j) of this section.

(C) If the vessel is controlled according to the provisions of § 63.119(e)(2) of this section whereby the control device is only required to achieve at least 90-percent reduction, the vessel shall not be considered to be generating debits.

(iii) The following equation shall be used for each internal floating roof vessel i that does not meet the specifications of § 63.119(b) or (d) of this subpart to calculate ESiACTUAL:

${\mathrm{ES}}_{\mathrm{iACTUAL}}=\frac{{L}_{W}+{L}_{R}+{L}_{F}+{L}_{D}}{12}$

where:
LW = Withdrawal loss emissions, megagrams per year, calculated according to paragraph (g)(3)(iii)(A) of this section.
LR = Rim seal loss emissions, megagrams per year, calculated according to paragraph (g)(3)(iii)(B) of this section.
LF = Fitting loss emissions, megagrams per year, calculated according to paragraph (g)(3)(iii)(C) of this section.
LD = Deck seam loss emissions, megagrams per year, calculated according to paragraph (g)(3)(iii)(D) of this section.
12 = Constant, months per year.

(A) Withdrawal loss emissions shall be calculated using the following equation:

${L}_{W}=\frac{1.018×{10}^{=5}{\mathrm{QCW}}_{L}}{D}\left[1+\left(\frac{{N}_{C}{F}_{C}}{D}\right)\right]$

where:
Q = Throughput, gallon per year; (gallon/turnover) * (turnovers per year).
C = Shell clingage factor, barrel per 1,000 square foot, see table 23 of this subpart.
WL = Average liquid density, pound per gallon.
D = Tank diameter, feet.
Nc = Number of columns, dimensionless, see table 24 of this subpart.
Fc = Effective column diameter, feet [column perimeter (feet) ÷ 3.1416], see table 25 of this subpart.

(B) Rim seal loss emissions shall be calculated using the following equation:

${L}_{R}=\frac{{K}_{s}{V}^{n}{P}^{*}D{M}_{v}{K}_{c}}{2,205}$

where:
Mv = Molecular weight of vapor in storage vessel, pound per pound-mole.
D = Tank diameter, feet.
Kc = Product factor, dimensionless; use 1.0 for organic HAP's.
Ks = Seal factor, pound-mole per [foot (miles per hour) n year], see table 26 of this subpart.
V = Average wind speed at the source, miles per hour. A value of 10 miles per hour may be assumed if source-specific data are not available.
n = Seal related wind speed exponent, dimensionless, see table 26 of this subpart.
2,205 = Constant, pounds per megagram.
P* = Vapor pressure function, dimensionless, and

${P}^{*}-\frac{\frac{P}{{P}_{A}}}{{\left[1+\left(1-\frac{P}{{P}_{A}}\right)0.5\right]}^{2}}$

where:
PA = Average atmospheric pressure, pounds per square inch absolute.
P = True vapor pressure at liquid storage temperature, pounds per square inch absolute.

(C) Fitting loss emissions shall be calculated using the following equation:

${L}_{F}=\frac{{F}_{f}{P}^{*}{M}_{v}{K}_{c}}{2,205}$

where:
Ff = The total deck fitting loss factor, pound-mole per year, and
where:

${F}_{f}=\sum _{i=1}^{n}\left({N}_{{F}_{i}}{K}_{{F}_{i}}\right)=\left[\left({N}_{{F}_{1}}{K}_{{F}_{1}}\right)+\left({N}_{{F}_{2}}{K}_{{F}_{2}}\right)+\dots +\left({N}_{{F}_{n}}{K}_{{F}_{n}}\right)\right]$

NFi = Number of fittings of a particular type, dimensionless. NFi is determined for the specific tank or estimated from tables 24 and 27 of this subpart.
KFi = Deck fitting loss factor for a particular type fitting, pound-mole per year. KFi is determined for each fitting type from table 27 of this subpart.
n = Number of different types of fittings, dimensionless.
P*, Mv, Kc, and 2,205 as defined in paragraph (g)(3)(iii)(B) of this section.

(D) Deck seam loss emissions shall be calculated using the following equation:

${L}_{D}=\frac{{K}_{D}{S}_{D}{{D}^{2}P}^{*}{M}_{v}{K}_{c}}{2,205}$

where:
KD = Deck seam loss factor, pound-mole per foot per year, and
KD = 0.34 for non-welded decks.
KD = 0 for welded decks.
SD = Deck seam length factor, feet per square foot, see table 28 of this subpart.
D, P*, Mv, Kc, and 2,205 as defined in paragraph (g)(3)(iii)(B) of this section.

(iv) The following equation shall be used for each external floating roof vessel i that does not meet the specifications of § 63.119(c) of this subpart to calculate ESiACTUAL:

${\mathrm{ES}}_{\mathrm{iACTUAL}}=\frac{{L}_{W}+{L}_{R}+{L}_{F}}{12}$

where:
LW = Withdrawal loss emissions, megagrams per year, calculated according to paragraph (g)(3)(iv)(A) of this section.
LR = Rim seal loss emissions, megagrams per year, calculated according to paragraph (g)(3)(iv)(B) of this section.
LF = Fitting loss emissions, megagrams per year, calculated according to paragraph (g)(3)(iv)(C) of this section.
12 = Constant, months per year.

(A) Withdrawal loss emissions shall be calculated using the following equation:

${L}_{W}=\frac{{4.28*10}^{-4}{\mathrm{QCW}}_{L}}{D}$

where:
Q = Throughput, gallons per year.
C = Shell clingage factor, barrel per 1,000 square foot, see table 23 of this subpart.
WL = Average liquid density, pound per gallon.
D = Vessel diameter, feet.

(B) Rim seal loss emissions shall be calculated using the following equation:

${L}_{R}=\frac{{K}_{s}{V}^{N}{P}^{*}D{M}_{v}{K}_{c}}{2,205}$

where:
Ks = Seal factor, pound-mole per [foot (miles per hour) N year], see table 29 of this subpart.
V = Average wind speed, miles per hour, at the source. A value of 10 miles per hour may be assumed if source-specific data are not available.
N = Seal wind speed exponent, dimensionless, see table 29 of this subpart.
P* = Vapor pressure function, dimensionless, as defined in paragraph (g)(3)(iii)(B) of this section.
D = Vessel diameter, feet.
MV = Molecular weight of the HAP, pound per pound-mole.
Kc = Product factor, dimensionless; use 1.0 for organic HAP's.
2,205 = Constant, pounds per megagram.

(C) Fitting loss emissions shall be calculated using the following equation:

${L}_{F}=\frac{{F}_{F}{P}^{*}{M}_{v}{K}_{c}}{2,205}$

where:
FF = The total deck fitting loss factor, pound-mole per year, and

${F}_{F}=\sum _{i=1}^{n}\left({N}_{{F}_{i}}{K}_{{F}_{i}}\right)=\left[\left({N}_{{F}_{1}}{K}_{{F}_{1}}\right)+\left({N}_{{F}_{2}}{K}_{{F}_{2}}\right)+\dots +\left({N}_{{F}_{n}}{K}_{{F}_{n}}\right)\right]$

where:
NFi = Number of fittings of a particular type, dimensionless. NFi is determined for the specific tank or estimated from tables 30 through 32 of this subpart.
KFi = Deck fitting loss factor for a particular type fitting, pound-mole per year, and
KFi = KFai + KFbi V mi, pound-mole per year, see table 30 of this subpart for the appropriate values of KFa, KFb, and m for each fitting type.
V, P*, Mv, Kc, and 2,205 as defined in paragraph (g)(3)(iv)(B) of this section.

(4) Emissions from transfer racks shall be calculated as follows:

(i) The following equation shall be used for each transfer rack i to calculate ETRiu:

${\mathrm{ETR}}_{\mathrm{iu}}=\left(1.20×{10}^{-7}\right)\frac{\mathrm{SPMG}}{T}$

where:
ETRiu = Uncontrolled transfer HAP emission rate from transfer rack i, megagrams per month.
S = Saturation factor, dimensionless (see table 33 of this subpart).
P = Weighted average rack partial pressure of organic HAP's transferred at the rack during the month, kilopascals.
M = Weighted average molecular weight of organic HAP's transferred at the transfer rack during the month, gram per gram-mole.
G = Monthly volume of organic HAP's transferred, liters per month.
T = Weighted rack bulk liquid loading temperature during the month, Kelvin ( °C + 273).

(ii) The following equation shall be used for each transfer rack i to calculate the weighted average rack partial pressure:

$P=\frac{\sum _{1}^{j=n}\left({P}_{j}\right)\left({G}_{j}\right)}{G}$

where:
Pj = Maximum true vapor pressure of individual organic HAP transferred at the rack, kilopascals.
G = Monthly volume of organic HAP transferred, liters per month, and

$G=\sum _{1}^{j=n}{G}_{j}$

Gj = Monthly volume of individual organic HAP transferred at the transfer rack, liters per month.
n = Number of organic HAP's transferred at the transfer rack.

(iii) The following equation shall be used for each transfer rack i to calculate the weighted average rack molecular weight:

$M=\frac{\sum _{1}^{j=n}\left({M}_{j}\right)\left({G}_{j}\right)}{G}$

where:
Mj = Molecular weight of individual organic HAP transferred at the rack, gram per gram-mole.
G, Gj, and n as defined in paragraph (g)(4)(ii) of this section.

(iv) The following equation shall be used for each transfer rack i to calculate the monthly weighted rack bulk liquid loading temperature:

$T=\frac{\sum _{1}^{j=n}\left({T}_{j}\right)\left({G}_{j}\right)}{G}$

where:
Tj = Average annual bulk temperature of individual organic HAP loaded at the transfer rack, Kelvin ((°C + 273).
G, Gj, and n as defined in paragraph (g)(4)(ii) of this section.

(v) The following procedures and equations shall be used to calculate ETRiACTUAL:

(A) If the transfer rack is not controlled, ETRiACTUAL = ETRiu, where ETRiu is calculated using the equations specified in paragraphs (g)(4)(i) through (g)(4)(iv) of this section.

(B) If the transfer rack is controlled using a control device or a pollution prevention measure achieving less than the 98-percent reduction,

${ETR}_{\mathrm{ACTUAL}}={ETR}_{\mathrm{iu}}\left(\frac{1-\text{Percent reduction}}{100%}\right)$

(1) The percent reduction for a control device shall be measured according to the procedures and test methods specified in § 63.128(a) of this subpart. For a flare meeting the criteria in § 63.128(b) of this subpart or a boiler or process heater meeting the criteria in § 63.128(c) of this subpart, the percent reduction shall be 98 percent. If testing is not feasible, percent reduction shall be determined through a design evaluation according to the procedures specified in § 63.128(h) of this subpart.

(2) Procedures for calculating the percent reduction for pollution prevention measures are specified in paragraph (j) of this section.

(5) Emissions from wastewater shall be calculated as follows:

(i) The following equation shall be used for each wastewater stream i to calculate EWWic:

$\begin{array}{c}{\mathrm{EWW}}_{\mathrm{ic}}=\left(6.0*{10}^{-8}\right){Q}_{i}{H}_{i}\sum _{m=1}^{s}\left(1-{\mathrm{Fr}}_{m}\right){\mathrm{Fe}}_{m}{\mathrm{HAP}}_{\mathrm{im}}\\ +\left(0.05\right)\left(6.0×{10}^{-8}\right){Q}_{i}{H}_{i}\sum _{m=1}^{s}\left({\mathrm{Fr}}_{m}{\mathrm{HAP}}_{\mathrm{im}}\right)\end{array}$

where:
EWWic = Monthly wastewater stream emission rate if wastewater stream i is controlled by the reference control technology, megagrams per month.
Qi = Average flow rate for wastewater stream i, as determined by the procedure in § 63.144(c)(3), liters per minute.
Hi = Number of hours during the month that wastewater stream i was generated, hours per month.
s = Total number of table 9 HAP in wastewater stream i.
Frm = Fraction removed of table 9 HAP m in wastewater, from table 9, dimensionless.
Fem = Fraction emitted of table 9 HAP m in wastewater, from table 34, dimensionless.
HAPim = Average concentration of table 9 HAP m in wastewater stream i, parts per million by weight.

(A) HAPim shall be determined for the point of determination or, at a location downstream of the point of determination and adjusted according as specified in § 63.144(b)(6) of this subpart, by developing and using the sampling plan specified in § 63.144(b)(5)(ii) of this subpart. The samples collected may be analyzed by any of the methods specified in § 63.144(b)(5)(i)(B) through (b)(5)(i)(F) of this subpart. Concentration measurements based on Method 305 shall be adjusted by dividing each concentration by the compound-specific Fm factor listed on table 34 of this subpart. Concentration measurements other than Method 305 shall not be adjusted by the compound-specific Fm factor listed in table 34 of this subpart.

(B) Values for Qi, HAPim, and Cim shall be determined during a performance test conducted under representative conditions as specified in § 63.145(a)(3) and (a)(4) of this subpart. The average value obtained from three test runs shall be used. The values of Qi, HAPim, and Cim shall be established in the Notification of Compliance Status and must be updated as provided in paragraph (g)(5)(i)(C) of this section.

(C) If there is a change to the process or operation such that the previously measured values of Qi, HAPim, and Cim are no longer representative, a new performance test shall be conducted to determine new representative values of Qi, HAPim, and Cim. These new values shall be used to calculate debits and credits from the time of the change forward, and the new values shall be reported in the next Periodic Report.

(ii) The following equation shall be used to calculate EWWiACTUAL for each wastewater stream i that is not managed according to the provisions for waste management units of §§ 63.133 through 63.137 of this subpart, as applicable, which specify equipment and work practices for suppressing and controlling vapors. Qi, Hi, s, Fem, and HAPim are as defined and determined according to paragraph (g)(5)(i) of this section.

${\mathrm{EWW}}_{\mathrm{iACTUAL}}=\left(6.0×{10}^{-8}\right){Q}_{i}{H}_{i}\sum _{m=1}^{s}{\mathrm{Fe}}_{m}{\mathrm{HAP}}_{\mathrm{im}}$

Where:
EWWiACTUAL = Monthly wastewater stream emission rate if wastewater stream i is uncontrolled or is controlled to a level less stringent than the reference control technology, megagrams per month.

(iii) The following equation shall be used to calculate EWWiACTUAL for each wastewater stream i that is managed according to the requirements of §§ 63.133 through 63.137 of this subpart, as applicable, and wastewater stream i is uncontrolled or is controlled to a level less stringent than the reference control technology (for the purposes of the wastewater emissions averaging provisions, the term control is used to mean treatment). Qi, Hi, s, Fem, and HAPim are as defined and determined according to paragraph (g)(5)(i) of this section.

$\begin{array}{c}{\mathrm{EWW}}_{\mathrm{iACTUAL}}=\left(6.0*{10}^{-8}\right){Q}_{i}{H}_{i}\phantom{\rule{0ex}{0ex}}\sum _{m=1}^{s}\left[{\mathrm{Fe}}_{m}{\mathrm{HAP}}_{\mathrm{im}}\left(1-{\mathrm{PR}}_{\mathrm{im}}\right)\right]\\ +\left(1-\frac{{R}_{i}}{100%}\right)\left(6.0*{10}^{-8}\right){Q}_{i}{H}_{i}\phantom{\rule{0ex}{0ex}}\sum _{m=1}^{s}\left({\mathrm{HAP}}_{\mathrm{im}}{\mathrm{PR}}_{\mathrm{im}}\right)\end{array}$

Where:
EWWiACTUAL = Monthly wastewater stream emission rate if wastewater stream i is uncontrolled or is controlled to a level less stringent than the reference control technology, megagrams per month.
PRim = The efficiency of the treatment process, or series of treatment processes, which treat wastewater stream i, in reducing the emission potential of table 9 HAP m in wastewater, dimensionless, as calculated by:

${\mathrm{PR}}_{\mathrm{im}}=\frac{{\mathrm{HAP}}_{\mathrm{im}-\mathrm{in}}-{\mathrm{HAP}}_{\mathrm{im}-\mathrm{out}}}{{\mathrm{HAP}}_{\mathrm{im}-\mathrm{in}}}$

Where:
HAPim-in = Average concentration of table 9 HAP m, parts per million by weight, as defined and determined according to paragraph (g)(5)(i) of this section, in the wastewater entering the first treatment process in the series.
HAPim-out = Average concentration of table 9 HAP m, parts per million by weight, as defined and determined according to paragraph (g)(5)(i) of this section, in the wastewater exiting the last treatment process in the series.
Ri = Reduction efficiency of the device used to control any vapor streams emitted and collected from wastewater stream i during treatment, dimensionless, as determined according to the procedures in § 63.145(i) or (j) of this subpart.

(h) Credits are generated by the difference between emissions that are allowed for each Group 1 and Group 2 emission point and the actual emissions from a Group 1 or Group 2 emission point that has been controlled after November 15, 1990 to a level more stringent than what is required by this subpart or any other State or Federal rule or statute. Credits shall be calculated as follows:

(1) The overall equation for calculating source-wide credits is:

$\begin{array}{c}\text{Credits}=D\phantom{\rule{0ex}{0ex}}\sum _{i=1}^{n}\left(\left(0.02\right){\mathrm{EPV}1}_{\mathrm{iu}}-{\mathrm{EPV}1}_{\mathrm{iACTUAL}}\right)+D\phantom{\rule{0ex}{0ex}}\sum _{i=1}^{m}\left({\mathrm{ECPV}2}_{\mathrm{iBASE}}-{\mathrm{EPV}2}_{\mathrm{iACTUAL}}\right)+D\phantom{\rule{0ex}{0ex}}\sum _{i=1}^{n}\\ \left(\left(0.05\right){\mathrm{ES}1}_{\mathrm{iu}}-{\mathrm{ES}1}_{\mathrm{iACTUAL}}\right)+D\phantom{\rule{0ex}{0ex}}\sum _{i=1}^{m}\left({\mathrm{ES}2}_{\mathrm{iBASE}}-{\mathrm{ES}2}_{\mathrm{iACTUAL}}\right)+D\phantom{\rule{0ex}{0ex}}\sum _{i=1}^{n}\left(\left(0.02\right){\mathrm{ETR}1}_{\mathrm{iu}}-{\mathrm{ETR}1}_{\mathrm{iACTUAL}}\right)\\ +D\phantom{\rule{0ex}{0ex}}\phantom{\rule{0ex}{0ex}}\sum _{i=1}^{n}\left({\mathrm{ETR}2}_{\mathrm{iBASE}}-{\mathrm{ETR}2}_{\mathrm{iACTUAL}}\right)+D\phantom{\rule{0ex}{0ex}}\sum _{i=1}^{n}\left({\mathrm{EWW}1}_{\mathrm{ic}}-{\mathrm{EWW}1}_{\mathrm{iACTUAL}}\right)+D\phantom{\rule{0ex}{0ex}}\phantom{\rule{0ex}{0ex}}\sum _{i=1}^{m}\left({\mathrm{EWW}2}_{\mathrm{iBASE}}-{\mathrm{EWW}2}_{\mathrm{iACTUAL}}\right)\end{array}$

where:
Credits and all terms of the equation are in units of megagrams per month, the baseline date is November 15, 1990, and:
D = Discount factor = 0.9 for all credit generating emission points except those controlled by a pollution prevention measure, which will not be discounted.
EPV1iACTUAL = Emissions for each Group 1 process vent i that is controlled to a level more stringent than the reference control technology, calculated according to paragraph (h)(2) of this section.
(0.02) EPV1iu = Emissions from each Group 1 process vent i if the reference control technology had been applied to the uncontrolled emissions. EPV1iu is calculated according to paragraph (h)(2) of this section.
EPV2iACTUAL = Emissions from each Group 2 process vent i that is controlled, calculated according to paragraph (h)(2) of this section.
EPV2iBASE = Emissions from each Group 2 process vent i at the baseline date, as calculated in paragraph (h)(2) of this section.
ES1iACTUAL = Emissions from each Group 1 storage vessel i that is controlled to a level more stringent than the reference control technology, calculated according to paragraph (h)(3) of this section.
(0.05) ES1iu = Emissions from each Group 1 storage vessel i if the reference control technology had been applied to the uncontrolled emissions. ES1iu is calculated according to paragraph (h)(3) of this section.
ES2iACTUAL = Emissions from each Group 2 storage vessel i that is controlled, calculated according to paragraph (h)(3) of this section.
ES2iBASE = Emissions from each Group 2 storage vessel i at the baseline date, as calculated in paragraph (h)(3) of this section.
ETR1iACTUAL = Emissions from each Group 1 transfer rack i that is controlled to a level more stringent than the reference control technology, calculated according to paragraph (h)(4) of this section.
(0.02) ETR1iu = Emissions from each Group 1 transfer rack i if the reference control technology had been applied to the uncontrolled emissions. ETR1iu is calculated according to paragraph (h)(4) of this section.
ETR2iACTUAL = Emissions from each Group 2 transfer rack i that are controlled, calculated according to paragraph (h)(4) of this section.
ETR2iBASE = Emissions from each Group 2 transfer rack i at the baseline date, as calculated in paragraph (h)(4) of this section.
EWW1iACTUAL = Emissions from each Group 1 wastewater stream i that is controlled to a level more stringent than the reference control technology, calculated according to paragraph (h)(5) of this section.
EWW1ic = Emissions from each Group 1 wastewater stream i if the reference control technology had been applied to the uncontrolled emissions, calculated according to paragraph (h)(5) of this section.
EWW2iACTUAL = Emissions from each Group 2 wastewater stream i that is controlled, calculated according to paragraph (h)(5) of this section.
EWW2iBASE = Emissions from each Group 2 wastewater stream i at the baseline date, calculated according to paragraph (h)(5) of this section.
n = Number of Group 1 emission points included in the emissions average. The value of n is not necessarily the same for process vents, storage vessels, transfer racks, and wastewater.
m = Number of Group 2 emission points included in the emissions average. The value of m is not necessarily the same for process vents, storage vessels, transfer racks, and wastewater.

(i) For an emission point controlled using a reference control technology, the percent reduction for calculating credits shall be no greater than the nominal efficiency associated with the reference control technology, unless a higher nominal efficiency is assigned as specified in paragraph (h)(1)(ii) of this section.

(ii) For an emission point controlled to a level more stringent than the reference control technology, the nominal efficiency for calculating credits shall be assigned as described in paragraph (i) of this section. A reference control technology may be approved for use in a different manner and assigned a higher nominal efficiency according to the procedures in paragraph (i) of this section.

(iii) For an emission point controlled using a pollution prevention measure, the nominal efficiency for calculating credits shall be as determined as described in paragraph (j) of this section.

(2) Emissions from process vents shall be determined as follows:

(i) Uncontrolled emissions from Group 1 process vents, EPV1iu, shall be calculated according to the procedures and equation for EPViu in paragraphs (g)(2)(i) and (g)(2)(ii) of this section.

(ii) Actual emissions from Group 1 process vents controlled using a technology with an approved nominal efficiency greater than 98 percent or a pollution prevention measure achieving greater than 98 percent emission reduction, EPV1iACTUAL, shall be calculated according to the following equation:

${E\mathrm{TV}1}_{\mathrm{ACTUAL}}={E\mathrm{TV}1}_{\mathrm{iu}}\left(1-\frac{\text{Nominal efficiency %}}{100%}\right)$

(iii) The following procedures shall be used to calculate actual emissions from Group 2 process vents, EPV2iACTUAL:

(A) For a Group 2 process vent controlled by a control device, a recovery device applied as a pollution prevention project, or a pollution prevention measure, if the control achieves a percent reduction less than or equal to 98 percent reduction,

${\mathrm{EPV}2}_{\mathrm{iACTUAL}}={\mathrm{EPV}2}_{\mathrm{iu}}\left(1-\frac{\text{Percent reduction}}{100%}\right)$

(1) EPV2iu shall be calculated according to the equations and procedures for EPViu in paragraphs (g)(2)(i) and (g)(2)(ii) of this section, except as provided in paragraph (h)(2)(iii)(A)(3) of this section.

(2) The percent reduction shall be calculated according to the procedures in paragraphs (g)(2)(iii)(B)(1) through (g)(2)(iii)(B)(3) of this section, except as provided in paragraph (h)(2)(iii)(A)(4) of this section.

(3) If a recovery device was added as part of a pollution prevention project, EPV2iu shall be calculated prior to that recovery device. The equation for EPViu in paragraph (g)(2)(ii) of this section shall be used to calculate EPV2iu; however, the sampling site for measurement of vent stream flow rate and organic HAP concentration shall be at the inlet of the recovery device.

(4) If a recovery device was added as part of a pollution prevention project, the percent reduction shall be demonstrated by conducting a performance test at the inlet and outlet of that recovery device.

(B) For a Group 2 process vent controlled using a technology with an approved nominal efficiency greater than 98 percent or a pollution prevention measure achieving greater than 98 percent reduction,

${\mathrm{EP}V2}_{\mathrm{iACTUAL}}={\mathrm{EPV}2}_{\mathrm{iu}}\left(1-\frac{\text{Nominal efficiency %}}{100%}\right)$

(iv) Emissions from Group 2 process vents at baseline, EPV2iBASE, shall be calculated as follows:

(A) If the process vent was uncontrolled on November 15, 1990, EPV2iBASE = EPV2iu and shall be calculated according to the procedures and equation for EPViu in paragraphs (g)(2)(i) and (g)(2)(ii) of this section.

(B) If the process vent was controlled on November 15, 1990,

${\mathrm{EP}V2}_{i\text{BASE}}={\mathrm{EPV}2}_{\mathrm{iu}}\left(1-\frac{\text{Percent reduction %}}{100%}\right)$

where EPV2iu is calculated according to the procedures and equation for EPViu in paragraphs (g)(2)(i) and (g)(2)(ii) of this section. The percent reduction shall be calculated according to the procedures specified in paragraphs (g)(2)(iii)(B)(1) through (g)(2)(iii)(B)(3) of this section.

(C) If a recovery device was added to a process vent as part of a pollution prevention project initiated after November 15, 1990, EPV2iBASE = EPV2iu, where EPV2iu is calculated according to paragraph (h)(2)(iii)(A)(3) of this section.

(3) Emissions from storage vessels shall be determined as follows:

(i) Uncontrolled emissions from Group 1 storage vessels, ES1iu, shall be calculated according to the equations and procedures for ESiu in paragraph (g)(3)(i) of this section.

(ii) Actual emissions from Group 1 storage vessels controlled using a technology with an approved nominal efficiency greater than 95 percent or a pollution prevention measure achieving greater than 95 percent emission reduction, ES1iACTUAL, shall be calculated according to the following equation:

${\mathrm{ES}1}_{i\text{ACTUAL}}={\mathrm{ES}1}_{\mathrm{iu}}\left(1-\frac{\text{Nominal efficiency %}}{100%}\right)$

(iii) The following procedures shall be used to calculate actual emissions from Group 2 storage vessels, ES2iACTUAL:

(A) For a Group 2 storage vessel controlled using a control device or a pollution prevention measure (other than an internal or external floating roof) achieving a percent reduction less than or equal to 95-percent reduction,

${\mathrm{ES}2}_{i\text{ACTUAL}}={\mathrm{ES}2}_{\mathrm{iu}}\left(1-\frac{\text{Percent reduction}}{100%}\right)$

(1) ES2iu is calculated according to the equations and procedures for ESiu in paragraph (g)(3)(i) of this section.

(2) The percent reduction shall be calculated according to the procedures in paragraphs (g)(3)(ii)(B)(1) and (g)(3)(ii)(B)(2) of this section.

(3) If an internal or external floating roof meeting the specifications of § 63.119 (b), (c), or (d) of this subpart is used to control the vessel, the percent reduction shall be 95 percent.

(B) If a Group 2 storage vessel is controlled with an internal or external floating roof not meeting the specifications of § 63.119 (b), (c), or (d) of this subpart, ES2iACTUAL shall be calculated as specified for ESiACTUAL in paragraph (g)(3)(iii) or (g)(3)(iv) of this section.

(C) For a Group 2 storage vessel controlled using a technology with an approved nominal efficiency greater than 95 percent or a pollution prevention measure achieving greater than 95 percent reduction,

${\mathrm{ES}2}_{i\text{ACTUAL}}={\mathrm{ES}2}_{\mathrm{iu}}\left(1-\frac{\text{Nominal efficiency %}}{100%}\right)$

(iv) Emissions from Group 2 storage vessels at baseline, ES2iBASE, shall be calculated as follows:

(A) If the fixed-roof vessel was uncontrolled on November 15, 1990, ES2iBASE = ES2iu and shall be calculated according to the procedures and equations for ESiu in paragraph (g)(3)(i) of this section.

(B) If the storage vessel was controlled on November 15, 1990:

(1) The equations for ESiACTUAL in paragraph (g)(3)(iii) of this section shall be used to calculate ES2iBASE for vessels controlled with an internal floating roof that does not meet the specifications of § 63.119 (b) or (d) of this subpart.

(2) The equations for ESiACTUAL in paragraph (g)(3)(iv) of this section shall be used to calculate ES2iBASE for vessels controlled with an external floating roof that does not meet the specifications of § 63.119(c) of this subpart.

(3) The following equations shall be used to calculate ES2iBASE for vessels controlled with a control device,

${\mathrm{ES}2}_{i\text{BASE}}={\mathrm{ES}2}_{w}\left(1-\frac{\text{Percent reduction %}}{100%}\right)$

where ES2iu shall be calculated according to the equations for ESiu in paragraph (g)(3)(i) of this section. The percent reduction shall be calculated according to the procedures in paragraphs (g)(3)(ii)(B)(1) and (g)(3)(ii)(B)(2) of this section.

(4) Emissions from transfer racks shall be determined as follows:

(i) Uncontrolled emissions from Group 1 transfer racks, ETR1iu, shall be calculated according to the procedures and equations for ETRiu as described in paragraphs (g)(4)(i) through (g)(4)(iv) of this section.

(ii) Actual emissions from Group 1 transfer racks controlled using a technology with an approved nominal efficiency greater than 98 percent or a pollution prevention measure achieving greater than 98 percent emission reduction, ETRiACTUAL, shall be calculated according to the following equation:

${ETR1}_{i\text{ACTUAL}}={ETR1}_{\mathrm{iu}}\left(1-\frac{\text{nominal efficiency}}{100%}\right)$

(iii) The following procedures shall be used to calculate actual emissions from Group 2 transfer racks, ETR2iACTUAL:

(A) For a Group 2 transfer rack controlled by a control device or a pollution prevention measure achieving a percent reduction less than or equal to 98 percent reduction,

${ETR2}_{i\text{ACTUAL}}={ETR2}_{\mathrm{iu}}\left(1-\frac{\text{Percent reduction}}{100%}\right)$

(1) ETR2iu shall be calculated according to the equations and procedures for ETRiu in paragraphs (g)(4)(i) through (g)(4)(iv) of this section.

(2) The percent reduction shall be calculated according to the procedures in paragraph (g)(4)(v)(B)(1) and (g)(4)(v)(B)(2) of this section.

(B) For a Group 2 transfer rack controlled using a technology with an approved nominal efficiency greater than 98 percent or a pollution prevention measure achieving greater than 98 percent reduction,

${ETR2}_{i\text{ACTUAL}}={ETR2}_{w}\left(1-\frac{\text{Nominal efficiency}}{100%}\right)$

(iv) Emissions from Group 2 transfer racks at baseline, ETR2iBASE, shall be calculated as follows:

(A) If the transfer rack was uncontrolled on November 15, 1990, ETR2iBASE = ETR2iu and shall be calculated according to the procedures and equations for ETRiu in paragraphs (g)(4)(i) through (g)(4)(iv) of this section.

(B) If the transfer rack was controlled on November 15, 1990,

${ETR2}_{i\text{BASE}}={ETR2}_{\mathrm{iu}}\left(1-\frac{\text{Percent reduction}}{100%}\right)$

where ETR2iu is calculated according to the procedures and equations for ETRiu in paragraphs (g)(4)(i) through (g)(4)(iv) of this section. Percent reduction shall be calculated according to the procedures in paragraphs (g)(4)(v)(B)(1) and (g)(4)(v)(B)(2) of this section.

(5) Emissions from wastewater shall be determined as follows:

(i) EWW1ic shall be calculated according to the equation for EWWic in paragraph (g)(5)(i) of this section.

(ii) EWW2iBASE shall be calculated according to the equation for EWWiACTUAL in paragraph (g)(5)(ii) of this section for each Group 2 wastewater stream i, which on November 15, 1990, was not managed according to the requirements of §§ 63.133 through 63.137 of this subpart, as applicable.

(iii) EWW2iBASE shall be calculated according to the equation for EWWiACTUAL in paragraph (g)(5)(iii) of this section for each Group 2 wastewater stream i, which on November 15, 1990, was managed according to the requirements of §§ 63.133 through 63.137 of this subpart, as applicable, and was uncontrolled or controlled to a level less stringent than the reference control technology.

(iv) For Group 2 wastewater streams that are managed according to the requirements of §§ 63.133 through 63.137 of this subpart, as applicable, EWW2iACTUAL shall be calculated as follows:

(A) EWW2iACTUAL shall be calculated according to the equation for EWWiACTUAL in paragraph (g)(5)(iii) of this section for each Group 2 wastewater stream i that is controlled to a level less stringent than, or equivalent to, the reference control technology.

(B) EWW2iACTUAL shall be calculated according to the procedures for calculating EWW1iACTUAL in paragraph (h)(5)(v) of this section for each Group 2 wastewater stream that is controlled to a level more stringent than the reference control technology.

(v) The following equations for EWW1iACTUAL shall be used to calculate emissions from each Group 1 wastewater stream i that is managed according to the requirements of §§ 63.133 through 63.137 of this subpart, as applicable, and is controlled to a level more stringent than the reference control technology.

(A) If the Group 1 wastewater stream i is controlled using a treatment process or series of treatment processes with an approved nominal reduction efficiency in the concentration of table 9 HAP for stream i greater than that of the design steam stripper specified in § 63.138(d) of this subpart, and the control device used to reduce table 9 HAP emissions from the vapor stream(s) vented from the treatment process(es) achieves a percent reduction equal to 95 percent, the following equation shall be used. All terms in this equation are as defined and determined in paragraph (g)(5) of this section.

$\begin{array}{c}{\mathrm{EWW}1}_{\mathrm{iACTUAL}}=\left(6.0*{10}^{-8}\right){Q}_{i}{H}_{i}\phantom{\rule{0ex}{0ex}}\sum _{m=1}^{s}\left[{\mathrm{Fe}}_{m}{\mathrm{HAP}}_{\mathrm{im}}\left(1-{\mathrm{PR}}_{\mathrm{im}}\right)\right]\\ +0.05\left(6.0*{10}^{-8}\right){Q}_{i}{H}_{i}\phantom{\rule{0ex}{0ex}}\sum _{m=1}^{s}\left({\mathrm{HAP}}_{\mathrm{im}}{\mathrm{PR}}_{\mathrm{im}}\right)\end{array}$

(B) If the Group 1 wastewater stream i is not controlled using a treatment process or series of treatment processes with a nominal reduction efficiency in the table 9 HAP concentration greater than that of the design steam stripper specified in § 63.138(d) of this subpart, but the vapor stream(s) vented from the treatment process(es) are controlled using a device with an approved nominal efficiency greater than 95 percent, the following equation shall be used. All terms other than nominal efficiency are as defined and determined in paragraph (g)(5) of this section.

$\begin{array}{c}{\mathrm{EWW}1}_{\mathrm{iACTUAL}}=\left(6.0*{10}^{-8}\right){Q}_{i}{H}_{i}\phantom{\rule{0ex}{0ex}}\sum _{m=1}^{s}\left[{\mathrm{Fe}}_{m}{\mathrm{HAP}}_{\mathrm{im}}\left(1-{\mathrm{FR}}_{m}\right)\right]\\ +\left(1-\frac{\text{Nominal Efficiency %}}{100}\right)\left(6.0*{10}^{-8}\right){Q}_{i}{H}_{i}\phantom{\rule{0ex}{0ex}}\sum _{m=1}^{s}\left({\mathrm{HAP}}_{\mathrm{im}}{\mathrm{Fr}}_{m}\right)\end{array}$

(C) If the Group 1 wastewater stream i is controlled using a treatment process or series of treatment processes with an approved nominal reduction efficiency in the table 9 HAP concentration greater than that of the design steam stripper specified in § 63.138(d) of this subpart, and the vapor stream(s) vented from the treatment process are controlled using a device with an approved nominal efficiency greater than 95 percent, the following equation shall be used. All terms other than nominal efficiency are as defined and determined in paragraph (g)(5) of this section.

$\begin{array}{c}{\mathrm{EWW}1}_{\mathrm{iACTUAL}}=\left(6.0*{10}^{-8}\right){Q}_{i}{H}_{i}\phantom{\rule{0ex}{0ex}}\sum _{m=1}^{s}\left[{\mathrm{Fe}}_{m}{\mathrm{HAP}}_{\mathrm{im}}\left(1-{\mathrm{PR}}_{\mathrm{im}}\right)\right]\\ +\left(1-\frac{\text{Nominal Efficiency %}}{100}\right)\left(6.0*{10}^{-8}\right){Q}_{i}{H}_{i}\phantom{\rule{0ex}{0ex}}\sum _{m=1}^{s}\left({\mathrm{HAP}}_{\mathrm{im}}{\mathrm{PR}}_{\mathrm{im}}\right)\end{array}$

(i) The following procedures shall be followed to establish nominal efficiencies. The procedures in paragraphs (i)(1) through (i)(6) of this section shall be followed for control technologies that are different in use or design from the reference control technologies and achieve greater percent reductions than the percent efficiencies assigned to the reference control technologies in § 63.111 of this subpart.

(1) In those cases where the owner or operator is seeking permission to take credit for use of a control technology that is different in use or design from the reference control technology, and the different control technology will be used in more than three applications at a single plant-site, the owner or operator shall submit the information specified in paragraphs (i)(1)(i) through (i)(1)(iv) of this section to the Director of the EPA Office of Air Quality Planning and Standards in writing:

(i) Emission stream characteristics of each emission point to which the control technology is or will be applied including the kind of emission point, flow, organic HAP concentration, and all other stream characteristics necessary to design the control technology or determine its performance.

(ii) Description of the control technology including design specifications.

(iii) Documentation demonstrating to the Administrator's satisfaction the control efficiency of the control technology. This may include performance test data collected using an appropriate EPA method or any other method validated according to Method 301 of appendix A of this part. If it is infeasible to obtain test data, documentation may include a design evaluation and calculations. The engineering basis of the calculation procedures and all inputs and assumptions made in the calculations shall be documented.

(iv) A description of the parameter or parameters to be monitored to ensure that the control technology will be operated in conformance with its design and an explanation of the criteria used for selection of that parameter (or parameters).

(2) The Administrator shall determine within 120 calendar days whether an application presents sufficient information to determine nominal efficiency. The Administrator reserves the right to request specific data in addition to the items listed in paragraph (i)(1) of this section.

(3) The Administrator shall determine within 120 calendar days of the submittal of sufficient data whether a control technology shall have a nominal efficiency and the level of that nominal efficiency. If, in the Administrator's judgment, the control technology achieves a level of emission reduction greater than the reference control technology for a particular kind of emission point, the Administrator will publish a Federal Register notice establishing a nominal efficiency for the control technology.

(4) The Administrator may condition permission to take emission credits for use of the control technology on requirements that may be necessary to ensure operation and maintenance to achieve the specified nominal efficiency.

(5) In those cases where the owner or operator is seeking permission to take credit for use of a control technology that is different in use or design from the reference control technology and the different control technology will be used in no more than three applications at a single plant site, the information listed in paragraphs (i)(1)(i) through (i)(1)(iv) can be submitted to the permitting authority for the source for approval instead of the Administrator.

(i) In these instances, use and conditions for use of the control technology can be approved by the permitting authority as part of an operating permit application or modification. The permitting authority shall follow the procedures specified in paragraphs (i)(2) through (i)(4) of this section except that, in these instances, a Federal Register notice is not required to establish the nominal efficiency for the different technology.

(ii) If, in reviewing the application, the permitting authority believes the control technology has broad applicability for use by other sources, the permitting authority shall submit the information provided in the application to the Director of the EPA Office of Air Quality Planning and Standards. The Administrator shall review the technology for broad applicability and may publish a Federal Register notice; however, this review shall not affect the permitting authority's approval of the nominal efficiency of the control technology for the specific application.

(6) If, in reviewing an application for a control technology for an emission point, the Administrator or permitting authority determines the control technology is not different in use or design from the reference control technology, the Administrator or permitting authority shall deny the application.

(j) The following procedures shall be used for calculating the efficiency (percent reduction) of pollution prevention measures:

(1) A pollution prevention measure is any practice which meets the criteria of paragraphs (j)(1)(i) and (j)(1)(ii) of this section.

(i) A pollution prevention measure is any practice that results in a lesser quantity of organic HAP emissions per unit of product released to the atmosphere prior to out-of-process recycling, treatment, or control of emissions, while the same product is produced.

(ii) Pollution prevention measures may include: substitution of feedstocks that reduce HAP emissions; alterations to the production process to reduce the volume of materials released to the environment; equipment modifications; housekeeping measures; and in-process recycling that returns waste materials directly to production as raw materials. Production cutbacks do not qualify as pollution prevention.

(2) The emission reduction efficiency of pollution prevention measures implemented after November 15, 1990, can be used in calculating the actual emissions from an emission point in the debit and credit equations in paragraphs (g) and (h) of this section. When the term “organic HAP” is used in § 63.150(j)(2) in reference to wastewater emission points, the term “table 9 HAP” shall apply for the purposes of this paragraph.

(i) For pollution prevention measures, the percent reduction used in the equations in paragraphs (g)(2) through (g)(5) of this section and paragraphs (h)(2) through (h)(5) of this section is the percent difference between the monthly organic HAP emissions for each emission point after the pollution prevention measure for the most recent month versus monthly emissions from the same emission point before the pollution prevention measure, adjusted by the volume of product produced during the two monthly periods.

(ii) The following equation shall be used to calculate the percent reduction of a pollution prevention measure for each emission point.

$\text{Percent reduction}-\frac{{E}_{B}-\frac{\left({E}_{\mathrm{pp}}×{P}_{B}\right)}{{P}_{\mathrm{pp}}}}{{E}_{B}}×100%$

where:
Percent reduction = Efficiency of pollution prevention measure (percent organic HAP reduction).
EB = Monthly emissions before the pollution prevention measure, megagrams per month, determined as specified in paragraphs (j)(2)(ii)(A), (j)(2)(ii)(B), and (j)(2)(ii)(C) of this section.
Epp = Monthly emissions after the pollution prevention measure, megagrams per month, as determined for the most recent month, determined as specified in paragraphs (j)(2)(ii)(D) or (j)(2)(ii)(E) of this section.
PB = Monthly production before the pollution prevention measure, megagrams per month, during the same period over which EB is calculated.
Ppp = Monthly production after the pollution prevention measure, megagrams per month, as determined for the most recent month.

(A) The monthly emissions before the pollution prevention measure, EB, shall be determined in a manner consistent with the equations and procedures in paragraphs (g)(2), (g)(3), and (g)(4) of this section for process vents, storage vessels, and transfer operations.

(B) For wastewater, EB shall be calculated as follows:

${E}_{B}=\sum _{i=1}^{n}\left[\left(6.0*{10}^{-8}\right){Q}_{\mathrm{Bi}}{H}_{\mathrm{Bi}}\sum _{m=1}^{s}{\mathrm{Fe}}_{m}{\mathrm{HAP}}_{\mathrm{Bim}}\right]$

Where:
n = Number of wastewater streams.
QBi = Average flow rate for wastewater stream i before the pollution prevention measure, defined and determined according to paragraph (g)(5)(i) of this section, liters per minute, before implementation of the pollution prevention measure.
HBi = Number of hours per month that wastewater stream i was discharged before the pollution prevention measure, hours per month.
s = Total number of table 9 HAP in wastewater stream i.
Fem = Fraction emitted of table 9 HAP m in wastewater of this subpart, dimensionless.
HAPBim = Average concentration of table 9 HAP m in wastewater stream i, defined and determined according to paragraph (g)(5)(i) of this section, before the pollution prevention measure, parts per million by weight, as measured before the implementation of the pollution measure.

(C) If the pollution prevention measure was implemented prior to April 22, 1994, records may be used to determine EB.

(D) The monthly emissions after the pollution prevention measure, Epp, may be determined during a performance test or by a design evaluation and documented engineering calculations. Once an emissions-to-production ratio has been established, the ratio can be used to estimate monthly emissions from monthly production records.

(E) For wastewater, Epp shall be calculated using the following equation:

${E}_{\mathrm{pp}}=\sum _{i=1}^{n}\left[\left(6.0*{10}^{-8}\right){Q}_{\mathrm{ppi}}{H}_{\mathrm{ppi}}\sum _{m=1}^{s}{\mathrm{Fe}}_{m}{\mathrm{HAP}}_{\mathrm{ppim}}\right]$

where n, Qppi, Hppi, s, Fem, and HAPppim are defined and determined as described in paragraph (j)(2)(ii)(B) of this section except that Qppi, Hppi, and HAPppim shall be determined after the pollution prevention measure has been implemented.

(iii) All equations, calculations, test procedures, test results, and other information used to determine the percent reduction achieved by a pollution prevention measure for each emission point shall be fully documented.

(iv) The same pollution prevention measure may reduce emissions from multiple emission points. In such cases, the percent reduction in emissions for each emission point must be calculated.

(v) For the purposes of the equations in paragraphs (h)(2) through (h)(5) of this section, used to calculate credits for emission points controlled more stringently than the reference control technology, the nominal efficiency of a pollution prevention measure is equivalent to the percent reduction of the pollution prevention measure. When a pollution prevention measure is used, the owner or operator of a source is not required to apply to the Administrator for a nominal efficiency and is not subject to paragraph (i) of this section.

(k) The owner or operator must demonstrate that the emissions from the emission points proposed to be included in the average will not result in greater hazard or, at the option of the operating permit authority, greater risk to human health or the environment than if the emission points were controlled according to the provisions in §§ 63.113 through 63.148.

(1) This demonstration of hazard or risk equivalency shall be made to the satisfaction of the operating permit authority.

(i) The Administrator may require owners and operators to use specific methodologies and procedures for making a hazard or risk determination.

(ii) The demonstration and approval of hazard or risk equivalency shall be made according to any guidance that the Administrator makes available for use.

(2) Owners and operators shall provide documentation demonstrating the hazard or risk equivalency of their proposed emissions average in their operating permit application or in their Implementation Plan if an operating permit application has not yet been submitted.

(3) An emissions averaging plan that does not demonstrate hazard or risk equivalency to the satisfaction of the Administrator shall not be approved. The Administrator may require such adjustments to the emissions averaging plan as are necessary in order to ensure that the average will not result in greater hazard or risk to human health or the environment than would result if the emission points were controlled according to §§ 63.113 through 63.148 of this subpart.

(4) A hazard or risk equivalency demonstration must:

(i) Be a quantitative, bona fide chemical hazard or risk assessment;

(ii) Account for differences in chemical hazard or risk to human health or the environment; and

(iii) Meet any requirements set by the Administrator for such demonstrations.

(l) For periods of excursions, an owner or operator may request that the provisions of paragraphs (l)(1) through (l)(4) of this section be followed instead of the procedures in paragraphs (f)(3)(i) and (f)(3)(ii) of this section.

(1) The owner or operator shall notify the Administrator of excursions in the Periodic Reports as required in § 63.152 of this subpart.

(2) The owner or operator shall demonstrate that other types of monitoring data or engineering calculations are appropriate to establish that the control device for the emission point was operating in such a fashion to warrant assigning full or partial credits and debits. This demonstration shall be made to the Administrator's satisfaction, and the Administrator may establish procedures of demonstrating compliance that are acceptable.

(3) The owner or operator shall provide documentation of the excursion and the other type of monitoring data or engineering calculations to be used to demonstrate that the control device for the emission point was operating in such a fashion to warrant assigning full or partial credits and debits.

(4) The Administrator may assign full or partial credit and debits upon review of the information provided.

(m) For each Group 1 or Group 2 emission point included in an emissions average, the owner or operator shall perform testing, monitoring, recordkeeping, and reporting equivalent to that required for Group 1 emission points complying with §§ 63.113 through 63.148 of this subpart. The specific requirements for process vents, storage vessels, transfer racks, and wastewater are identified in paragraphs (m)(1) through (m)(6) of this section.

(1) The source shall implement the following testing, monitoring, recordkeeping, and reporting procedures for each process vent equipped with a flare, incinerator, boiler, or process heater.

(i) Determine, consistent with paragraph (g)(2)(i) of this section, whether the process vent is Group 1 or Group 2 according to the procedures in § 63.115.

(ii) Conduct initial performance tests to determine percent reduction as specified in § 63.116 of this subpart;

(iii) Monitor the operating parameters, keep records, and submit reports specified in § 63.114, § 63.117(a), and § 63.118 (a), (f), and (g) of this subpart, as appropriate for the specific control device.

(2) The source shall implement the following procedures for each process vent equipped with a carbon adsorber, absorber, or condenser but not equipped with a control device:

(i) Determine, consistent with paragraph (g)(2)(i) of this section, the flow rate, organic HAP concentration, and TRE index value using the methods specified in § 63.115;

(ii) Monitor the operating parameters, keep records, and submit reports specified in § 63.114, § 63.117(a), and § 63.118(b), (f), and (g) of this subpart, as appropriate for the specific recovery device.

(3) The source shall implement the following procedures for each storage vessel controlled with an internal floating roof, external roof, or a closed vent system with a control device, as appropriate to the control technique:

(i) Perform the monitoring or inspection procedures in § 63.120 of this subpart,

(ii) Perform the reporting and recordkeeping procedures in §§ 63.122 and 63.123 of this subpart, and

(iii) For closed vent systems with control devices, conduct an initial design evaluation and submit an operating plan as specified in § 63.120(d) and § 63.122(a)(2) and (b) of this subpart.

(4) The source shall implement the following procedures for each transfer rack controlled with a vapor balancing system, or a vapor collection system and an incinerator, flare, boiler, process heater, adsorber, condenser, or absorber, as appropriate to the control technique:

(i) The monitoring and inspection procedures in § 63.127 of this subpart,

(ii) The testing and compliance procedures in § 63.128 of this subpart, and

(iii) The reporting and recordkeeping procedures in § 63.129 and § 63.130 of this subpart.

(5) The source shall implement the following procedures for wastewater emission points, as appropriate to the control techniques:

(i) For wastewater treatment processes, conduct tests as specified in § 63.138(j) of this subpart.

(ii) Conduct inspections and monitoring as specified in § 63.143 of this subpart.

(iii) A recordkeeping program as specified in § 63.147 of this subpart.

(iv) A reporting program as specified in § 63.146 of this subpart.

(6) If an emission point in an emissions average is controlled using a pollution prevention measure or a device or technique for which no monitoring parameters or inspection procedures are specified in § 63.114, § 63.120, § 63.127, or § 63.143 of this subpart, the owner or operator shall submit the information specified in § 63.151(f) of this subpart in the Implementation Plan or operating permit application.

(n) Records of all information required to calculate emission debits and credits shall be retained for five years.

(o) Initial Notifications, Implementation Plans, Notifications of Compliance Status, Periodic Reports, and other reports shall be submitted as required by § 63.151 and § 63.152 of this subpart.

[59 FR 19468, Apr. 22, 1994, as amended at 60 FR 63628, Dec. 12, 1995; 64 FR 20192, Apr. 26, 1999; 66 FR 6934, Jan. 22, 2001]