ADOPTED REGULATION OF THE 

STATE ENVIRONMENTAL COMMISSION 

LCB File No. R126-10 

Effective December 16, 2010 

EXPLANATION – Matter in italics is new; matter in brackets [omitted material] is material to be omitted. 

AUTHORITY: §§1-5, NRS 445B.210. 

A REGULATION relating to air pollution; revising the definition of “stationary source”; 

revising certain provisions relating to environmental evaluations; revising certain 

provisions concerning the measurement of maximum heat input for the purpose of 

determining the effects of a Class I source on the quality of ambient air; and providing 

other matters properly relating thereto. 

 Section 1. NAC 445B.138 is hereby amended to read as follows: 

 445B.138 “Potential to emit” means the maximum capacity of a stationary source to emit a 

regulated air pollutant under its physical and operational design. Any physical or operational 

limitation on the capacity of a stationary source to emit a regulated air pollutant, including 

equipment for the control of air pollution and any restrictions on the hours of operation of the 

stationary source or on the type or amount of material combusted, stored or processed, may be 

treated as part of its design for the purposes of determining its potential to emit if the limitation is 

federally enforceable . [by the Director.]

 Sec. 2. NAC 445B.187 is hereby amended to read as follows: 

 445B.187 1. “Stationary source” means all buildings, structures, facilities and 

installations, including temporary sources, which: 

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Adopted Regulation R126-10 
 (a) Belong to the same major industrial groupings described in the Standard Industrial 

Classification Manual, as incorporated by reference in NAC 445B.221; 

 (b) Are located on one or more contiguous or adjacent properties; 

 (c) Are owned or operated by the same person or by persons under common control; and 

 (d) Emit or may emit any regulated air pollutant that is regulated under 42 U.S.C. §§ 7401 to 

7671q, inclusive, or NAC 445B.001 to 445B.3791, inclusive. 

 2. Contracted operations that support the primary operations of the stationary source are part 

of the stationary source, except that temporary construction activities, including, without 

limitation, the construction of emission units, are not part of the stationary source. 

 3. The term does not include motor vehicles, [special mobile equipment,] nonroad engines 

and nonroad vehicles. 

 Sec. 3. NAC 445B.311 is hereby amended to read as follows: 

 445B.311 1. An environmental evaluation which is required for a new or modified 

stationary source pursuant to NAC 445B.308 to 445B.314, inclusive, or as required by the 

Director must contain a careful and detailed assessment of the environmental aspects of the 

proposed stationary source and must also contain: 

 (a) The name and address of the applicant; 

 (b) The name, address and location of the stationary source; 

 (c) A description of the proposed stationary source, including the normal hours of operation 

of the facility and the general types of activities to be performed; 

 (d) A map showing the location of the stationary source and the topography of the area, 

including existing principal streets, roads and highways within 3 miles of the stationary source; 

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 (e) A site plan showing the location and height of buildings on the site; 

 (f) Any additional information or documentation which the Director deems necessary to 

determine the effect of the stationary source on the quality of the ambient air, including 

measured data on the quality of the ambient air and meteorological conditions at the proposed 

site before construction or modification; and 

 (g) A dispersion analysis of each regulated air pollutant. 

 2. Where approval is sought for stationary sources to be constructed in phases, the 

information required by subsection 1 must be submitted for each phase of the construction 

project. 

 3. An environmental evaluation must also consider good engineering practice stack height. 

If the Director considers an analysis of a source based on a good engineering practice stack 

height that exceeds the height specified in paragraph (a) or (b) of subsection 1 of NAC 

445B.083, the Director shall: 

 (a) Notify the public of the availability of the demonstration study performed pursuant to 

paragraph (c) of subsection 1 of NAC 445B.083; and 

 (b) Provide an opportunity for a public hearing on the demonstration study in accordance 

with the requirements for a Class I operating permit set forth in subsections 7, 9 and 10 of NAC 

445B.3395. 

 4. A dispersion analysis used to determine the location and estimated value of the highest 

concentration of each regulated air pollutant must include: 

 (a) A dispersion model based on the applicable models, bases and other requirements 

specified in the “Guideline on Air Quality Models,” which is Appendix W of 40 C.F.R. Part 51, 

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as adopted by reference in NAC 445B.221, except that the Director may authorize the 

modification of a model specified in the “Guideline on Air Quality Models” or the use of a 

model not included in the “Guideline on Air Quality Models” if the Director [determines] : 

 (1) Determines that the modification or use is appropriate;

 (2) Obtains written approval of the modification or use from the Administrator; and 

 (3) Provides notice of and establishes a 30-day period for comment in accordance with 

the applicable provisions of NAC 445B.3364, 445B.3395, 445B.3447, 445B.3457 or 

445B.3477; 

 (b) A narrative report describing: 

 (1) If applicable, assumptions and premises used in the analysis, including, without 

limitation: 

 (I) Model options chosen; 

 (II) Urban versus rural selection; 

 (III) Background concentrations; 

 (IV) Characterization of emission sources as point, area or volume; 

 (V) Emission discharge points; and 

 (VI) Rate of emission from each emission unit; and 

 (2) The geographic area considered in the analysis, including, without limitation, 

information concerning: 

 (I) The nearest significant terrain features; 

 (II) The receptor grid or grids; and 

 (III) Restrictions on public access to the stationary source; and 

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Adopted Regulation R126-10 
 (c) Valid meteorological information pursuant to the provisions of Appendix W of 40 C.F.R. 

Part 51, as adopted by reference in NAC 445B.221, which: 

 (1) For sources that are not subject to the permitting requirements of 40 C.F.R. § 52.21, as 

adopted by reference in NAC 445B.221: 

 (I) Is site specific, if the information exists pursuant to subsection 1 of this section or 

subsection 7 of NAC 445B.308, and which covers a period of not less than 1 year; 

 (II) Has been obtained from an off-site location representative of the proposed site and 

which covers a period of not less than 1 year; 

 (III) Represents the worst-case meteorological conditions, as approved by the Director 

for synthetic data; or 

 (IV) Has been obtained over the last 5 years at the nearest National Weather Service 

site; or 

 (2) For sources that are subject to the permitting requirements of 40 C.F.R. § 52.21, as 

adopted by reference in NAC 445B.221, is representative of the source site location and source 

emissions and which covers a period of not less than 1 year.

 Sec. 4. NAC 445B.313 is hereby amended to read as follows: 

 445B.313 For the purposes of determining the effects of Class I sources on the quality of 

ambient air and determining the applicability of a federally enforceable standard or requirement 

to an emission unit, the maximum heat input will be determined by : 

 1. Multiplying the maximum fuel rate as determined by the manufacturer by the total 

calorific value of the fuel as determined by using the appropriate method of ASTM International

[.] ; or 

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 2. An alternative method specified by the Director as a condition contained in the 

operating permit of the Class I source. 

 Sec. 5. NAC 445B.179 is hereby repealed. 

TEXT OF REPEALED SECTION

445B.179 “Special mobile equipment” defined. (NRS 445B.210) “Special mobile 

equipment” has the meaning ascribed to it in NRS 482.123.