NR 661.1081(14)
(14) “
Liquid-mounted seal” means a foam or liquid-filled primary seal mounted in contact with the hazardous secondary material between the tank wall and the floating roof continuously around the circumference of the tank.
NR 661.1081(15)
(15) “
Malfunction” means any sudden, infrequent, and not reasonably preventable failure of air pollution control equipment, process equipment, or a process to operate in a normal or usual manner. A failure that is caused in part by poor maintenance or careless operation is not a malfunction.
NR 661.1081(16)
(16) “
Material determination” means performing all applicable procedures in accordance with the requirements specified in s.
NR 661.1084 to determine whether a hazardous secondary material meets standards specified in this subchapter. Examples of a material determination include performing the procedures in accordance with the requirements specified in s.
NR 661.1084 to determine the average VO concentration of a hazardous secondary material at the point of material origination; the average VO concentration of a hazardous secondary material at the point of material treatment and comparing the results to the exit concentration limit specified for the process used to treat the hazardous secondary material; the organic reduction efficiency and the organic biodegradation efficiency for a biological process used to treat a hazardous secondary material and comparing the results to the applicable standards; or the maximum volatile organic vapor pressure for a hazardous secondary material in a tank and comparing the results to the applicable standards.
NR 661.1081(17)
(17) “
Maximum organic vapor pressure” means the sum of the individual organic constituent partial pressures that are exerted by the material contained in a tank, and reasonably expected to occur in the tank at the maximum vapor pressure-causing conditions, such as temperature, agitation, or pH effects of combining materials. For the purpose of this subchapter, maximum organic vapor pressure is determined using the procedures specified in s.
NR 661.1084 (3).
NR 661.1081(18)
(18) “
Metallic shoe seal” means a continuous seal that is constructed of metal sheets that are held vertically against the wall of the tank by springs, weighted levers, or other mechanisms and is connected to the floating roof by braces or other means. A flexible coated fabric or envelope spans the annular space between the metal sheet and the floating roof.
NR 661.1081(19)
(19) “
No detectable organic emissions” means no escape of organics to the atmosphere as determined using the procedure specified in s.
NR 661.1084 (4).
NR 661.1081(20)
(20) “
Point of material origination” means one of the following:
NR 661.1081(20)(a)
(a) When the remanufacturer or other person that stores or treats the hazardous secondary material is the generator of the hazardous secondary material, the point of material origination means the point where a material produced by a system, process, or material management unit is determined to be a hazardous secondary material excluded under s.
NR 661.0004 (1) (za).
NR 661.1081 Note
Note: In this case, this term is being used in a manner similar to the use of the term “point of generation” in air standards established for waste management operations in
40 CFR parts 60,
61 and
63, or subject to ch.
NR 440, subchs.
III and
IV of ch. NR 446, or chs.
NR 447 to
469.
NR 661.1081(20)(b)
(b) When the remanufacturer or other person that stores or treats the hazardous secondary material is not the generator of the hazardous secondary material, point of material origination means the point where the remanufacturer or other person that stores or treats the hazardous secondary material accepts delivery or takes possession of the hazardous secondary material.
NR 661.1081(21)
(21) “
Safety device” means a closure device such as a pressure relief valve, frangible disc, fusible plug, or any other type of device that functions exclusively to prevent physical damage or permanent deformation to a unit or its air emission control equipment by venting gases or vapors directly to the atmosphere during unsafe conditions resulting from an unplanned, accidental, or emergency event. For the purpose of this subchapter, a safety device is not used for routine venting of gases or vapors from the vapor headspace underneath a cover such as during filling of the unit or to adjust the pressure in this vapor headspace in response to normal daily diurnal ambient temperature fluctuations. A safety device is designed to remain in a closed position during normal operations and open only when the internal pressure, or another relevant parameter, exceeds the device threshold setting applicable to the air emission control equipment as determined by the remanufacturer or other person that stores or treats the hazardous secondary material based on manufacturer recommendations, applicable regulations, fire protection and prevention codes, standard engineering codes and practices, or other requirements for the safe handling of flammable, ignitable, explosive, reactive, or hazardous materials.
NR 661.1081(22)
(22) “
Single-seal system” means a floating roof having one continuous seal. This seal may be vapor-mounted, liquid-mounted, or a metallic shoe seal.
NR 661.1081(23)
(23) “Vapor-mounted seal” means a continuous seal that is mounted such that there is a vapor space between the hazardous secondary material in the unit and the bottom of the seal.
NR 661.1081(24)
(24) “
Volatile organic concentration” or “VO concentration” means the fraction by weight of the volatile organic compounds contained in a hazardous secondary material expressed in terms of parts per million or ppmw as determined by direct measurement or by knowledge of the material in accordance with the requirements specified in s.
NR 661.1084. For the purpose of determining the VO concentration of a hazardous secondary material, organic compounds with a Henry's law constant value of at least 0.1 mole-fraction-in-the-gas-phase/mole-fraction-in-the-liquid-phase (0.1 Y/X), which can also be expressed as 1.8 x 10
-6atmospheres/gram-mole/m
3, at 25
°C shall be included.
NR 661.1081 History
History: CR 19-082: cr.
Register August 2020 No. 776, eff. 9-1-20; correction in (5) (a) made under s.
35.17, Stats.,
Register August 2020 No. 776.
NR 661.1082(1)(1)
This section applies to the management of hazardous secondary material in tanks and containers subject to this subchapter.
NR 661.1082(2)
(2) A remanufacturer or other person that stores or treats hazardous secondary material shall control air pollutant emissions from each hazardous secondary material management unit in accordance with standards specified in ss.
NR 661.1084 to
661.1087, as applicable to the hazardous secondary material management unit, except as provided for in sub.
(3).
NR 661.1082(3)
(3) A tank or container is exempt from standards specified in ss.
NR 661.1084 to
661.1087, as applicable, provided that the hazardous secondary material management unit is a tank or container for which all hazardous secondary material entering the unit has an average VO concentration at the point of material origination of less than 500 parts per million by weight or ppmw. The average VO concentration shall be determined using the procedures specified in s.
NR 661.1083 (1). The remanufacturer or other person that stores or treats the hazardous secondary material shall review and update, as necessary, this determination at least once every 12 months following the date of the initial determination for the hazardous secondary material streams entering the unit.
NR 661.1082 History
History: CR 19-082: cr.
Register August 2020 No. 776, eff. 9-1-20.
NR 661.1083
NR 661.1083
Material determination procedures. NR 661.1083(1)(1)
Material determination procedure to determine average volatile organic (vo) concentration of a hazardous secondary material at the point of material origination. NR 661.1083(1)(a)(a) Determining average VO concentration at the point of material origination. A remanufacturer or other person that stores or treats the hazardous secondary material shall determine the average VO concentration at the point of material origination for each hazardous secondary material placed in a hazardous secondary material management unit exempted under the provisions of s.
NR 661.1082 (3) from using air emission controls in accordance with standards specified in ss.
NR 661.1084 to
661.1087, as applicable to the hazardous secondary material management unit.
The remanufacturer or other person that stores or treats the hazardous secondary material shall make the determinations according to all of the following:
NR 661.1083(1)(a)1.
1. Make an initial determination of the average VO concentration of the material stream before the first time any portion of the material in the hazardous secondary material stream is placed in a hazardous secondary material management unit exempted under the provisions of s.
NR 661.1082 (3) from using air emission controls, and thereafter make an initial determination of the average VO concentration of the material stream for each averaging period that a hazardous secondary material is managed in the unit.
NR 661.1083(1)(a)2.
2. Perform a new material determination whenever changes to the source generating the material stream are reasonably likely to cause the average VO concentration of the hazardous secondary material to increase to a level that is equal to or greater than the applicable VO concentration limits specified in s.
NR 661.1082.
NR 661.1083(1)(b)
(b)
Determination of average VO concentration using direct measurement or knowledge. For a material determination that is required under par.
(a), the average VO concentration of a hazardous secondary material at the point of material origination shall be determined using either direct measurement as specified in par.
(c) or by knowledge as specified in par.
(d).
NR 661.1083(1)(c)
(c)
Direct measurement to determine average VO concentration of a hazardous secondary material at the point of material origination. NR 661.1083(1)(c)1.1.
`Identification.' The remanufacturer or other person that stores or treats the hazardous secondary material shall identify and record in a log that is kept at the facility the point of material origination for the hazardous secondary material.
NR 661.1083(1)(c)2.
2. `Sampling.' Samples of the hazardous secondary material stream shall be collected at the point of material origination in a manner such that volatilization of organics contained in the material and in the subsequent sample is minimized and an adequately representative sample is collected and maintained for analysis by the selected method.The remanufacturer or other person that samples the hazardous secondary material shall sample according to all of the following:
NR 661.1083(1)(c)2.a.
a. The averaging period to be used for determining the average VO concentration for the hazardous secondary material stream on a mass-weighted average basis shall be designated and recorded. The averaging period can represent any time interval that the remanufacturer or other person that stores or treats the hazardous secondary material determines is appropriate for the hazardous secondary material stream but may not exceed one year.
NR 661.1083(1)(c)2.b.
b. A sufficient number of samples, but no less than 4 samples, shall be collected and analyzed for a hazardous secondary material determination. All of the samples for a given material determination shall be collected within a one-hour period. The average of the 4 or more sample results constitutes a material determination for the material stream. One or more material determinations may be required to represent the complete range of material compositions and quantities that occur during the entire averaging period due to normal variations in the operating conditions for the source or process generating the hazardous secondary material stream. Examples of such normal variations are seasonal variations in material quantity or fluctuations in ambient temperature.
NR 661.1083(1)(c)2.c.
c. All samples shall be collected and handled in accordance with written procedures prepared by the remanufacturer or other person that stores or treats the hazardous secondary material and documented in a site sampling plan. This plan shall describe the procedure by which representative samples of the hazardous secondary material stream are collected such that a minimum loss of organics occurs throughout the sample collection and handling process, and by which sample integrity is maintained. A copy of the written sampling plan shall be maintained at the facility. An example of acceptable sample collection and handling procedures for a total volatile organic constituent concentration may be found in Method 25D in appendix A of
40 CFR part 60, incorporated by reference in s.
NR 660.11.
NR 661.1083(1)(c)2.d.
d. Sufficient information, as specified in the site sampling plan required under subd.
2. c., shall be prepared and recorded to document the material quantity represented by the samples and, as applicable, the operating conditions for the source or process generating the hazardous secondary material represented by the samples.
NR 661.1083(1)(c)3.
3. `Analysis.' Each collected sample shall be prepared and analyzed in accordance with Method 25D in appendix A of
40 CFR part 60, incorporated by reference in s.
NR 660.11, for the total concentration of volatile organic constituents, or using one or more methods when the individual organic compound concentrations are identified and summed and the summed material concentration accounts for and reflects all organic compounds in the material with Henry's law constant values at least 0.1 mole-fraction-in-the-gas-phase/mole-fraction-in-the-liquid-phase (0.1 Y/X), which can also be expressed as 1.8 x 10
-6 atmospheres/gram-mole/m
3, at 25
°C. At the discretion of the remanufacturer or other person that stores or treats the hazardous secondary material, the test data obtained may be adjusted by any appropriate method to discount any contribution to the total volatile organic concentration that is a result of including a compound with a Henry's law constant value of less than 0.1 Y/X at 25
°C. To adjust these data, the measured concentration of each individual chemical constituent contained in the material is multiplied by the appropriate constituent-specific adjustment factor (f
m25D). If the remanufacturer or other person that stores or treats the hazardous secondary material elects to adjust the test data, the adjustment shall be made to all individual chemical constituents with a Henry's law constant value greater than or equal to 0.1 Y/X at 25
°C contained in the material. Constituent-specific adjustment factors (f
m25D) can be obtained by contacting the Waste and Chemical Processes Group, Office of Air Quality Planning and Standards, Research Triangle Park, NC 27711. Other test methods may be used if they meet the requirements specified in subd.
3. a. or
b. and provided the requirement to reflect all organic compounds in the material with Henry's law constant values greater than or equal to 0.1 Y/X, which can also be expressed as 1.8 x 10
-6atmospheres/gram-mole/m
3 at 25
°C, is met.
NR 661.1083(1)(c)3.a.
a. Any EPA standard method that has been validated in accordance with “Alternative Validation Procedure for EPA Waste and Wastewater Methods,” appendix D of
40 CFR part 63, incorporated by reference in s.
NR 660.11.
NR 661.1083(1)(c)3.b.
b. Any other analysis method that has been validated in accordance with the procedures specified in Section 5.1 or Section 5.3, and the corresponding calculations in Section 6.1 or Section 6.3 of Method 301 in appendix A of
40 CFR part 63, incorporated by reference in s.
NR 660.11. The data are acceptable if they meet the criteria specified in Section 6.1.5 or Section 6.3.3 of Method 301. If correction is required under Section 6.3.3 of Method 301, the data are acceptable if the correction factor is within the range 0.7 to 1.30. Other sections of Method 301 are not required.
NR 661.1083(1)(c)4.a.a. The average VO concentration (C) on a mass-weighted basis shall be calculated by using the results for all material determinations conducted in accordance with subds.
2. and
3. and the following equation:
Where:
C = Average VO concentration of the hazardous secondary material at the point of material origination on a mass-weighted basis, ppmw.
i = Individual material determination “i” of the hazardous secondary material.
n = Total number of material determinations of the hazardous secondary material conducted for the averaging period (not to exceed 1 year).
Qi = Mass quantity of hazardous secondary material stream represented by Ci, kg/hr.
QT = Total mass quantity of hazardous secondary material during the averaging period, kg/hr.
Ci = Measured VO concentration of material determination “i” as determined in accordance with the requirements specified in subd. 3., which is the average of the 4 or more samples specified in subd. 2. b., ppmw.
NR 661.1083(1)(c)4.b.
b. For the purpose of determining C
i, for individual material samples analyzed in accordance with subd.
3., the remanufacturer or other person that stores or treats the hazardous secondary material shall account for VO concentrations determined to be below the limit of detection of the analytical method by using the following VO concentration:
1) If Method 25D in appendix A of
40 CFR part 60, incorporated by reference in s.
NR 660.11, is used for the analysis, one-half the blank value determined in the method at Section 4.4 of Method 25D in appendix A of
40 CFR part 60.
2) If any other analytical method is used, one-half the sum of the limits of detection established for each organic constituent in the material that has a Henry's law constant values at least 0.1 mole-fraction-in-the-gas-phase/mole-fraction-in-the-liquid-phase (0.1 Y/X), which can also be expressed as 1.8 x 10-6atmospheres/gram-mole/m3 , at 25°C
.
NR 661.1083(1)(d)
(d)
Use of knowledge by the remanufacturer or other person that stores or treats the hazardous secondary material to determine average VO concentration of a hazardous secondary material at the point of material origination. NR 661.1083(1)(d)1.
1. The remanufacturer or other person that stores or treats the hazardous secondary material shall prepare documentation that presents the information used as the basis for the knowledge of the hazardous secondary material stream's average VO concentration. Examples of information that may be used as the basis for knowledge include material balances for the source or process generating the hazardous secondary material stream; constituent-specific chemical test data for the hazardous secondary material stream from previous testing that are still applicable to the current material stream; previous test data for other locations managing the same type of material stream; or other knowledge based on information included in shipping papers or material certification notices.
NR 661.1083(1)(d)2.
2. If test data are used as the basis for knowledge, then the remanufacturer or other person that stores or treats the hazardous secondary material shall document the test method, sampling protocol, and the means by which sampling variability and analytical variability are accounted for in the determination of the average VO concentration. For example, a remanufacturer or other person that stores or treats the hazardous secondary material may use organic concentration test data for the hazardous secondary material stream that are validated in accordance with Method 301 in appendix A of
40 CFR part 63, incorporated by reference in s.
NR 660.11, as the basis for knowledge of the waste.
NR 661.1083(1)(d)3.
3. A remanufacturer or other person that stores or treats the hazardous secondary material using chemical constituent-specific concentration test data as the basis for knowledge of the hazardous secondary material may adjust the test data to the corresponding average VO concentration value that would have been obtained had the material samples been analyzed using Method 25D in appendix A of
40 CFR part 60, incorporated by reference in s.
NR 660.11. To adjust these data, the measured concentration for each individual chemical constituent contained in the material is multiplied by the appropriate constituent-specific adjustment factor (f
m25D).
NR 661.1083(1)(d)4.
4. In the event that the department and the remanufacturer or other person that stores or treats the hazardous secondary material disagree on a determination of the average VO concentration for a hazardous secondary material stream using knowledge, then the results from a determination of average VO concentration using direct measurement as specified in par.
(c) shall be used to establish compliance with the applicable requirements of this subchapter. The department may perform or request that the remanufacturer or other person that stores or treats the hazardous secondary material perform this determination using direct measurement. The remanufacturer or other person that stores or treats the hazardous secondary material may choose one or more appropriate methods to analyze each collected sample in accordance with the requirements specified in par.
(c) 3. NR 661.1083(3)
(3) Procedure to determine the maximum organic vapor pressure of a hazardous secondary material in a tank. NR 661.1083(3)(a)(a) A remanufacturer or other person that stores or treats hazardous secondary material shall determine the maximum organic vapor pressure for each hazardous secondary material placed in a tank using Tank Level 1 controls in accordance with standards specified in s.
NR 661.1084 (3).
NR 661.1083(3)(b)
(b) A remanufacturer or other person that stores or treats hazardous secondary material shall use either direct measurement as specified in par.
(c) or knowledge of the waste as specified in par.
(d) to determine the maximum organic vapor pressure that is representative of the hazardous secondary material composition stored or treated in the tank.
NR 661.1083(3)(c)
(c) Direct measurement to determine the maximum organic vapor pressure of a hazardous secondary material shall be conducted using all of the following procedures:
NR 661.1083(3)(c)1.
1. A sufficient number of samples shall be collected to be representative of the hazardous secondary material contained in the tank. All samples shall be collected and handled in accordance with written procedures prepared by the remanufacturer or other person that stores or treats the hazardous secondary material and documented in a site sampling plan. This plan shall describe the procedure by which representative samples of the hazardous secondary material are collected such that a minimum loss of organics occurs throughout the sample collection and handling process and by which sample integrity is maintained. A copy of the written sampling plan shall be maintained at the facility. An example of acceptable sample collection and handling procedures may be found in Method 25D in appendix A of
40 CFR part 60, incorporated by reference in s.
NR 660.11.
NR 661.1083(3)(c)2.
2. Any appropriate one of the following methods may be used to analyze the samples and compute the maximum organic vapor pressure of the hazardous secondary material:
NR 661.1083(3)(c)2.b.
b. Methods described in American Petroleum Institute Publication 2517, Third Edition, February 1989, “Evaporative Loss from External Floating-Roof Tanks
,” incorporated by reference in s.
NR 660.11.
NR 661.1083(3)(d)
(d) A remanufacturer or other person that stores or treats hazardous secondary material may use knowledge to determine the maximum organic vapor pressure of the hazardous secondary material. Documentation shall be prepared and recorded that presents the information used as the basis for the knowledge by the remanufacturer or other person that stores or treats the hazardous secondary material that the maximum organic vapor pressure of the hazardous secondary material is less than the maximum vapor pressure limit specified in s.
NR 661.1084 (2) (a) 1. for the applicable tank design capacity category. An example of information that may be used is documentation that the hazardous secondary material is generated by a process for which at other locations it previously has been determined by direct measurement that the hazardous secondary material's waste maximum organic vapor pressure is less than the maximum vapor pressure limit for the appropriate tank design capacity category.
NR 661.1083(4)
(4)
Procedure for determining no detectable organic emissions for the purpose of complying with this subchapter. NR 661.1083(4)(a)(a)
A remanufacturer or other person that stores or treats hazardous secondary material shall conduct a test to determine no detectable organic emissions for the purpose of complying with this chapter in accordance with the procedures specified in Method 21 in appendix A of
40 CFR part 60, incorporated by reference in s.
NR 660.11. Each potential leak interface, a location where organic vapor leakage could occur, on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated with covers and closure devices include the interface of the cover and its foundation mounting, the periphery of any opening on the cover and its associated closure device, and the sealing seat interface on a spring-loaded pressure relief valve.
NR 661.1083(4)(b)
(b) The test shall be performed when the unit contains a hazardous secondary material having an organic concentration representative of the range of concentrations for the hazardous secondary material expected to be managed in the unit. During the test, the cover and closure devices shall be secured in the closed position.
NR 661.1083(4)(c)
(c) The detection instrument shall meet the performance criteria of Method 21 in appendix A of
40 CFR part 60, incorporated by reference in s.
NR 660.11, except the instrument response factor criteria in Section 3.1.2(a) of Method 21 shall be for the average composition of the organic constituents in the hazardous secondary material placed in the hazardous secondary management unit, not for each individual organic constituent.
NR 661.1083(4)(d)
(d) The detection instrument shall be calibrated before use on each day of its use by the procedures specified in Method 21 in appendix A of
40 CFR part 60, incorporated by reference in s.
NR 660.11.
NR 661.1083(4)(e)2.
2. A mixture of methane or n-hexane and air at a concentration of approximately, but less than, 10,000 ppmv methane or n-hexane.
NR 661.1083(4)(g)
(g) Each potential leak interface shall be checked by traversing the instrument probe around the potential leak interface as close to the interface as possible, as described in Method 21 in appendix A of
40 CFR part 60, incorporated by reference in s.
NR 660.11. In the case when the configuration of the cover or closure device prevents a complete traverse of the interface, all accessible portions of the interface shall be sampled. In the case when the configuration of the closure device prevents any sampling at the interface and the device is equipped with an enclosed extension or horn, such as some pressure relief devices, the instrument probe inlet shall be placed at approximately the center of the exhaust area to the atmosphere.
NR 661.1083(4)(h)
(h) The arithmetic difference between the maximum organic concentration indicated by the instrument and the background level shall be compared with the value of 500 ppmv except when monitoring a seal around a rotating shaft that passes through a cover opening, in which case the comparison shall be as specified in par.
(i). If the difference is less than 500 ppmv, then the potential leak interface is determined to operate with no detectable organic emissions.
NR 661.1083(4)(i)
(i) For the seals around a rotating shaft that passes through a cover opening, the arithmetic difference between the maximum organic concentration indicated by the instrument and the background level shall be compared with the value of 10,000 ppmw. If the difference is less than 10,000 ppmw, then the potential leak interface is determined to operate with no detectable organic emissions.
NR 661.1083 History
History: CR 19-082: cr.
Register August 2020 No. 776, eff. 9-1-20;
correction in (1) (a) 1. (intro.), 1., (3) (d) made under s. 13.92 (4) (b) 7., Stats., Register April 2021 No. 784. NR 661.1084(1)(1)
The provisions of this section apply to the control of air pollutant emissions from tanks for which s.
NR 661.1082 (2) references the use of this section for such air emission control.
NR 661.1084(2)
(2) The remanufacturer or other person that stores or treats the hazardous secondary material shall control air pollutant emissions from each tank subject to this section in accordance with one of the following requirements as applicable:
NR 661.1084(2)(a)
(a) For a tank that manages hazardous secondary material that meets all of the conditions specified in subds.
1. to
2., the remanufacturer or other person that stores or treats the hazardous secondary material shall control air pollutant emissions from the tank in accordance with the Tank Level 1 controls specified in sub.
(3) or the Tank Level 2 controls specified in sub.
(4).
NR 661.1084(2)(a)1.
1. The hazardous secondary material in the tank has a maximum organic vapor pressure less than the maximum organic vapor pressure limit for the tank's design capacity category as follows:
NR 661.1084(2)(a)1.a.
a. For a tank design capacity equal to or greater than 151 m
3, the maximum organic vapor pressure limit for the tank is 5.2 kPa.
NR 661.1084(2)(a)1.b.
b. For a tank design capacity equal to or greater than 75 m
3 but less than 151 m
3, the maximum organic vapor pressure limit for the tank is 27.6 kPa.
NR 661.1084(2)(a)1.c.
c. For a tank design capacity less than 75 m
3, the maximum organic vapor pressure limit for the tank is 76.6 kPa.
NR 661.1084(2)(a)2.
2. The hazardous secondary material in the tank is not heated by the remanufacturer or other person that stores or treats the hazardous secondary material to a temperature that is greater than the temperature at which the maximum organic vapor pressure of the hazardous secondary material is determined for the purpose of complying with subd.
1. NR 661.1084(2)(b)
(b) For a tank that manages hazardous secondary material that does not meet all of the conditions specified in par.
(a) 1. and
2., the remanufacturer or other person that stores or treats the hazardous secondary material shall control air pollutant emissions from the tank by using Tank Level 2 controls in accordance with the requirements under sub.
(4). An example of a tank required to use Tank Level 2 controls is a tank for which the hazardous secondary material in the tank has a maximum organic vapor pressure that is equal to or greater than the maximum organic vapor pressure limit for the tank's design capacity category as specified in par.
(a) 1.
