50-State Emergency Generator Emissions & Air Laws
State-by-state Department of Environmental Protection air quality operating permits, EPA Tier 4 Final non-road diesel standards, and annual non-emergency maintenance run-time caps.
| State | Governing Environmental Air Quality Agency | Permit-by-Rule (PBR) Exemption Threshold | Annual Non-Emergency Run-Time Limit | Ultra-Low Sulfur Diesel (ULSD) Mandate |
|---|---|---|---|---|
| Alabama | ADEM Air Division (Rule 335-3) | PBR under 500 HP / General Air Permit | 100 hrs/year (EPA 40 CFR 60 IIII) | ≤ 15 ppm Sulfur ULSD Mandatory |
| Alaska | ADEC Division of Air Quality | Exempt < 500 kW / Remote Arctic Rules | 100 hrs/year non-emergency | ULSD #1 / #2 Diesel Standard |
| Arizona | ADEQ Air Quality Division / Maricopa Rule 324 | Mandatory Registration > 250 HP | 50 hrs/yr (Maricopa Non-Attainment) | 15 ppm Sulfur ULSD Mandatory |
| Arkansas | ADEQ Office of Air Quality (Regulation 18/19) | De Minimis Exemption < 1,000 HP | 100 hrs/year standard | Mandatory Ultra-Low Sulfur Diesel |
| California | CARB Airborne Toxic Control Measure (ATCM) | Mandatory Air District Permit (All > 50 HP) | 20–50 hrs/yr (SCAQMD Rule 1470) | CARB Ultra-Low Sulfur Diesel & DEF |
| Colorado | CDPHE Air Pollution Control Division | Exempt < 260 HP / APEN > 260 HP | 100 hrs/year (Ozone Non-Attainment) | 15 ppm Sulfur ULSD Mandatory |
| Connecticut | CT DEEP Air Bureau (RCSA § 22a-174-3b) | Permit-by-Rule for Emergency Engines | 300 hrs/year emergency combined cap | Mandatory Ultra-Low Sulfur Fuel |
| Delaware | DNREC Division of Air Quality (Regulation 1144) | Mandatory Permit for Engines > 450 kW | 100 hrs/year non-emergency | 15 ppm Sulfur ULSD Mandatory |
| Florida | Florida DEP Division of Air Resource (FAC 62-210) | Categorical Exemption ≤ 2,000 kW (ULSD) | 100 hrs/year testing cap | Mandatory Ultra-Low Sulfur Diesel |
| Georgia | Georgia EPD Air Protection Branch (Rule 391-3-1) | PBR Exemption < 1,500 kW Standby | 100 hrs/year maintenance limit | 15 ppm Sulfur ULSD Mandatory |
| Hawaii | Hawaii DOH Clean Air Branch (HAR 11-60.1) | Exempt < 50 HP / Covered Source Permit | 100 hrs/year non-emergency | Ultra-Low Sulfur Diesel |
| Idaho | Idaho DEQ Air Quality Division (IDAPA 58.01.01) | Exempt < 1,000 HP Emergency Standby | 100 hrs/year testing limit | 15 ppm Sulfur ULSD Mandatory |
| Illinois | Illinois EPA Bureau of Air (35 IAC 201) | Exempt < 1,500 HP Standby Units | 100 hrs/year (Chicago Area Cap) | Mandatory Ultra-Low Sulfur Fuel |
| Indiana | IDEM Office of Air Quality (326 IAC 2-1.1) | Exempt < 1,000 HP / Registration > 1k HP | 100 hrs/year maintenance limit | 15 ppm Sulfur ULSD Mandatory |
| Iowa | Iowa DNR Air Quality Bureau (567 IAC 22) | PBR Exemption < 400 HP / Registration | 100 hrs/year non-emergency | Mandatory Ultra-Low Sulfur Diesel |
| Kansas | KDHE Bureau of Air (KAR 28-19) | Exempt < 1,000 HP Emergency Units | 100 hrs/year testing limit | 15 ppm Sulfur ULSD Mandatory |
| Kentucky | Kentucky DAQ (401 KAR 52) | Registered Source Exemption < 1,000 HP | 100 hrs/year standard | Mandatory Ultra-Low Sulfur Fuel |
| Louisiana | Louisiana DEQ Air Quality (LAC 33:III) | Regulatory Permit for Standby Generators | 100 hrs/year non-emergency | 15 ppm Sulfur ULSD Mandatory |
| Maine | Maine DEP Bureau of Air Quality (Chapter 115) | Exempt < 1,000 HP / General License | 100 hrs/year maintenance limit | Mandatory Ultra-Low Sulfur Diesel |
| Maryland | MDE Air & Radiation (COMAR 26.11.36) | PBR for Emergency Engines < 1,000 HP | 100 hrs/year testing cap | 15 ppm Sulfur ULSD Mandatory |
| Massachusetts | MassDEP (310 CMR 7.26 Emergency Engine PBR) | Mandatory ERA Filing for Engines > 300 kW | 300 hrs/year total emergency cap | 15 ppm Sulfur ULSD + Sound Standard |
| Michigan | EGLE Air Quality Division (Rule 285) | Permit to Install (PTI) Exemption < 10 MMBtu | 100 hrs/year maintenance limit | Mandatory Ultra-Low Sulfur Diesel |
| Minnesota | MPCA Air Quality (MN Rules 7007) | Insignificant Facility Status < 500 HP | 100 hrs/year testing limit | 15 ppm Sulfur ULSD Mandatory |
| Mississippi | MDEQ Air Division (11 Miss. Admin. Code) | Exempt < 1,000 HP Standby Generators | 100 hrs/year standard | Mandatory Ultra-Low Sulfur Fuel |
| Missouri | Missouri DNR Air Pollution Control (10 CSR 10) | De Minimis Exemption < 1,500 HP | 100 hrs/year non-emergency | 15 ppm Sulfur ULSD Mandatory |
| Montana | Montana DEQ Air Quality Bureau (ARM 17.8) | Exempt < 500 HP / Registration > 500 HP | 100 hrs/year testing limit | Mandatory Ultra-Low Sulfur Diesel |
| Nebraska | NDEE Air Quality Division (Title 129) | Exempt Emergency Standby < 1,000 HP | 100 hrs/year standard | 15 ppm Sulfur ULSD Mandatory |
| Nevada | NDEP Bureau of Air Pollution / Clark County | Mandatory Authority to Construct > 250 HP | 100 hrs/year (50 hrs/yr Clark County) | 15 ppm Sulfur ULSD Mandatory |
| New Hampshire | NHDES Air Resources Division (Env-A 600) | General State Permit for Emergency Engines | 100 hrs/year testing limit | Mandatory Ultra-Low Sulfur Diesel |
| New Jersey | NJDEP Division of Air Quality (NJAC 7:27-8) | General Permit GP-005A (Emergency Gensets) | 100 hrs/year non-emergency | 15 ppm Sulfur ULSD Mandatory |
| New Mexico | NMED Air Quality Bureau (20.2.72 NMAC) | Notice of Intent (NOI) Exemption < 1,000 HP | 100 hrs/year standard | Mandatory Ultra-Low Sulfur Diesel |
| New York | NYS DEC Division of Air Resources / NYC DEP | Air Facility Registration (NYC Work Permit) | 100 hrs/year (NYC Ultra-Low NOX Rule) | 15 ppm Sulfur ULSD & Tier 4 DEF |
| North Carolina | NC DAQ (15A NCAC 02Q .0102) | Exemption < 1,000 HP / Registration | 100 hrs/year maintenance limit | Mandatory Ultra-Low Sulfur Fuel |
| North Dakota | ND DEQ Division of Air Quality (NDAC 33.1-15) | Exempt < 1,000 HP Emergency Engines | 100 hrs/year testing limit | 15 ppm Sulfur ULSD Mandatory |
| Ohio | Ohio EPA Division of Air Pollution (OAC 3745-31) | Permit-by-Rule (PBR) OAC 3745-31-03(B) | 100 hrs/year non-emergency | Mandatory Ultra-Low Sulfur Diesel |
| Oklahoma | ODEQ Air Quality Division (OAC 252:100) | PBR Exemption < 1,000 HP Emergency Units | 100 hrs/year standard | 15 ppm Sulfur ULSD Mandatory |
| Oregon | Oregon DEQ Air Quality (OAR 340-216) | General ACDP Permit for Large Standby | 100 hrs/year non-emergency | Mandatory Ultra-Low Sulfur Fuel |
| Pennsylvania | PA DEP Bureau of Air Quality (25 Pa. Code) | General Permit GP-9 (Diesel IC Engines) | 100 hrs/year testing limit | 15 ppm Sulfur ULSD Mandatory |
| Rhode Island | RIDEM Office of Air Resources (Air Pollution Reg 9) | Mandatory Minor Source Permit > 1,000 HP | 100 hrs/year maintenance cap | Mandatory Ultra-Low Sulfur Diesel |
| South Carolina | SC DHEC Bureau of Air Quality (Regulation 61-62) | Exempt < 1,000 HP Emergency Standby | 100 hrs/year standard | 15 ppm Sulfur ULSD Mandatory |
| South Dakota | SD DANR Air Quality Program (ARSD 74:36) | Exempt < 1,000 HP Emergency Generators | 100 hrs/year testing limit | 15 ppm Sulfur ULSD Mandatory |
| Tennessee | TDEC Division of Air Pollution Control | PBR for Emergency Internal Combustion | 100 hrs/year non-emergency | Mandatory Ultra-Low Sulfur Fuel |
| Texas | TCEQ Air Permits Division (30 TAC § 106.511) | Standard Permit by Rule (PBR 106.511) | 100 hrs/year maintenance limit | 15 ppm Sulfur ULSD Mandatory |
| Utah | Utah DAQ (UAC R307-401) | Small Source Exemption < 1,000 HP | 100 hrs/year (Wasatch Front Cap) | 15 ppm Sulfur ULSD Mandatory |
| Vermont | Vermont DEC Air Quality & Climate Division | Air Permit Required for Engines > 450 HP | 100 hrs/year testing limit | Mandatory Ultra-Low Sulfur Diesel |
| Virginia | VDEQ Air Division (9 VAC 5 Chapter 80) | True Minor Exemption < 1,000 HP | 100 hrs/year non-emergency | 15 ppm Sulfur ULSD Mandatory |
| Washington | Washington State Ecology / Puget Sound Clean Air | Notice of Construction (NOC) > 500 HP | 50–100 hrs/year local agency cap | Mandatory Ultra-Low Sulfur Fuel |
| West Virginia | WV DEP Division of Air Quality (45 CSR 13) | De Minimis Exemption < 1,000 HP | 100 hrs/year standard | 15 ppm Sulfur ULSD Mandatory |
| Wisconsin | Wisconsin DNR Air Management (NR 406/407) | Exemption < 1,000 HP Emergency Standby | 100 hrs/year maintenance limit | Mandatory Ultra-Low Sulfur Diesel |
| Wyoming | Wyoming DEQ Air Quality Division (WAQSR) | Exempt Emergency Standby Units | 100 hrs/year testing limit | 15 ppm Sulfur ULSD Mandatory |