Results for “engine NOx”
- CalculatorEngine Emissions CalculatorStationary reciprocating engines driving compressors, pumps, or generators.
- ResourcePotential to emit, explained for engineersWhat PTE is, how it differs from actual emissions, why enforceable limits matter, and how to document the calculation.
- ResourceEngine Inventory (template)Stationary engine data used for NSPS/NESHAP screening and emission calculations.
- StateNew Hampshire air permitsNew Hampshire Department of Environmental Services (NHDES). NHDES is the sole permitting authority statewide (no local air agencies). New or modified sources above the device/source thresholds in Env-A 600 need a Temporary Permit (construction, up to 18 months), followed by a State Permit to Operate (up to 5 years) or a Title V Operating Permit (5 years). Alternatives include General State Permits for emergency engines and Permit-by-Notification for rock crushers. Although New Hampshire is in attainment for ozone, it is in the Northeast Ozone Transport Region, so nonattainment NSR applies to major NOx and VOC sources (Env-A 618); PSD is under Env-A 619.
- StateColorado air permitsColorado Department of Public Health and Environment (CDPHE). Colorado uses a two-step system: sources report emissions on an Air Pollutant Emission Notice (APEN) above APEN thresholds, and need a construction permit above facility-wide permit thresholds (Regulation 3, Parts A and B). Lower thresholds apply for VOC and NOx in the Denver Metro/North Front Range ozone nonattainment area. General permits cover common oil and gas equipment, engines, and land development. Major sources need a Title V operating permit (Regulation 3, Part C) and PSD/NNSR review (Regulation 3, Part D). Since June 30, 2026, APENs and construction permit applications must be filed through the online submission tool, and applications require an Environmental Justice Summary.
- ToolEmission CalculatorTransparent equipment-based emission calculations.
- ToolAir Quality JobsAir permitting, EHS, and environmental engineering jobs.
- RegulationNSPS — New Source Performance Standards40 CFR Part 60. Performance standards for new, modified, and reconstructed sources.
- RegulationNESHAP — National Emission Standards for Hazardous Air Pollutants40 CFR Parts 61 and 63. Hazardous air pollutant standards, including MACT and GACT source categories.
- StateVermont air permitsVermont Agency of Natural Resources, Department of Environmental Conservation (DEC). Vermont DEC's Air Quality & Climate Division issues a Permit to Construct before construction of a new or modified air contaminant source (sources listed in §5-401 of the Vermont Air Pollution Control Regulations; Subchapter V), and a Permit to Operate for facilities above the potential-emissions level in Subchapter X (see the Permit to Operate entry), which incorporates Title V. Most permits are combined Permits to Construct and Operate. Vermont implements federal NSR/PSD and Title V within its state program, so the state permit is the only construction or operating permit needed. DEC publishes source category guidance (boilers, engines, evaporators, breweries, quarries, asphalt, coating, and others). There are no local air agencies.
- StateNew York air permitsNew York State Department of Environmental Conservation (NYSDEC). NYSDEC issues air permits and registrations under 6 NYCRR Part 201: Air Facility Registrations (Subpart 201-4) for smaller non-major facilities, State Facility Permits (Subpart 201-5) for larger non-major facilities using enforceable limits, and Title V Facility Permits (Subpart 201-6) for major and Acid Rain sources. Major projects need nonattainment NSR under Part 231 or federal PSD under 40 CFR 52.21. Major source thresholds vary by location: the New York City metropolitan severe ozone nonattainment area has the lowest NOx/VOC thresholds. Permit processing follows the Uniform Procedures Act (Part 621). EPA Region 2 is the permitting authority in the eight Tribal Nations.
- StateRhode Island air permitsRhode Island Department of Environmental Management (DEM). RI DEM's Office of Air Resources issues preconstruction permits under Air Pollution Control Regulation No. 9 (250-RICR-120-05-9): minor source permits (with exemptions, general permits, temporary permits, and expedited processing), major source permits in nonattainment areas, and PSD permits in attainment areas. Operating permits for major sources are issued under Regulation No. 29 (250-RICR-120-05-29), with fees under Regulation No. 28. Rhode Island's VOC and NOx major source threshold under Regulation 29 is lower than the federal default (see the Title V entry). There are no local air agencies.
- StatePennsylvania air permitsPennsylvania Department of Environmental Protection (DEP). Pennsylvania DEP requires a plan approval before constructing, modifying, or reactivating a source or installing an air cleaning device (25 Pa. Code Chapter 127, Subchapter B), and an operating permit (State-Only or Title V, Subchapter F and Title V provisions) to operate. Many sources are exempt from plan approval under 25 Pa. Code 127.14 and DEP's Air Quality Permit Exemptions list (275-2101-003), but plan approval exemptions do not automatically exempt a facility from operating permits. A Request for Determination (RFD) gets a case-by-case decision. General plan approvals/general operating permits (GP-1 to GP-24) cover common source types, including GP-5 and GP-5A for natural gas operations. Allegheny County and Philadelphia run their own programs. Annual operating permit maintenance fees apply (2026-2030: $10,000 Title V, $5,000 synthetic minor, $2,500 natural minor).
- StateConnecticut air permitsConnecticut Department of Energy and Environmental Protection (DEEP). Connecticut DEEP issues equipment-specific New Source Review permits under RCSA § 22a-174-3a, with permit-by-rule alternatives for certain equipment (§§ 22a-174-3b, -3c, -3d) and premises-wide Title V operating permits under § 22a-174-33. Facilities can stay below Title V with emissions caps under §§ 22a-174-33a and -33b, which replaced the expired General Permit to Limit Potential to Emit. Southwest Connecticut was reclassified to severe nonattainment for the 2008 ozone standard, lowering major source thresholds for NOx and VOC there.
- StateWest Virginia air permitsWest Virginia Department of Environmental Protection (WVDEP). WVDEP's Division of Air Quality issues construction, modification, relocation, and temporary permits under 45CSR13 for stationary sources above the rule's thresholds, plus Class I and Class II general permit registrations (filed through the Electronic Submission System), PSD permits (45CSR14), nonattainment NSR permits (45CSR19), and Title V operating permits (45CSR30). Fees are under 45CSR22. A Permit Determination request confirms whether a permit is needed. West Virginia has extensive oil and gas general permits: G70-E for well sites and G35-E for compressor and dehydration facilities. There are no local air agencies.
- StateDelaware air permitsDelaware Department of Natural Resources and Environmental Control (DNREC). In Delaware, any equipment that emits or controls air contaminants needs DNREC approval before construction or operation under 7 DE Admin. Code 1102, unless exempt or eligible for registration. Sources are classified as natural minor, synthetic minor, or major. Major sources are subject to NSR/PSD (Regulation 1125) and Title V (Regulation 1130). Major source thresholds for VOC and NOx are lower in New Castle and Kent counties than in Sussex County.
- StateKansas air permitsKansas Department of Health and Environment (KDHE). Kansas requires a state construction permit (K.A.R. 28-19-300(a)) or, below permit thresholds, a construction approval (28-19-300(b)) before beginning actual construction or modification. Operating permits are Class I (Kansas's Title V permit) or Class II (federally enforceable limits, including permits-by-rule). PSD is implemented under K.A.R. 28-19-350, adopting portions of 40 CFR 52.21. All applications go through KEIMS.
- StateTennessee air permitsTennessee Department of Environment and Conservation (TDEC). TDEC's Division of Air Pollution Control requires a construction permit before building or modifying an air contaminant source unless it is exempt (Rule 1200-03-09), followed by an operating permit: true minor, conditional major (limits to stay below Title V), or Title V. Combined construction/operating permits are available. General permits (via Notice of Intent and Notice of Coverage) and Permits by Rule (via NOI and Notice of Authorization, Rule 1200-03-09-.07) cover listed categories. Major sources need PSD (BACT) in attainment areas or nonattainment NSR (LAER). Four local programs (Chattanooga-Hamilton, Knox, Memphis-Shelby, Nashville-Davidson) permit in their areas. Non-confidential submittals can be emailed to Air.Pollution.Control@tn.gov.
- StateDistrict of Columbia air permitsDC Department of Energy and Environment (DOEE). Most stationary sources of air pollution in the District must obtain permits from DOEE's Air Quality Division. Minor sources (such as gas stations, dry cleaners, auto body shops, generator sites, and small printers) generally need a Chapter 2 pre-construction review permit and then a Chapter 2 operating permit. Major sources need pre-construction review, NSR permits under 20 DCMR § 204 for new major sources or emission-increasing modifications, and Title V operating permits under 20 DCMR Chapter 3. Source category permits offer a fast standardized path for emergency engines and temporary portable plants.
- StateGeorgia air permitsGeorgia Environmental Protection Division (EPD). Georgia EPD requires an air permit before beginning construction or modification that may cause air pollution, unless exempt (Rule 391-3-1-.03(1), (2), (6)). Minor and synthetic minor sources get SIP construction and operating permits; some categories can accept a permit-by-rule (which still requires a SIP permit). Major sources need PSD/112(g) construction permits and Title V (Part 70) permits filed through GEOS. Projects subject to Georgia's VOC or NOx RACT rules must always be permitted with public notice.
- StateFlorida air permitsFlorida Department of Environmental Protection (DEP). Florida DEP requires an air construction permit before building or modifying non-exempt emissions units, and an air operation permit to operate. Many small sources qualify for categorical, conditional, or generic exemptions (Rule 62-210.300(3), F.A.C.) or for one of the air general permits (Rule 62-210.310). Minor construction permits are processed by DEP districts or approved local programs; PSD, nonattainment NSR, and power plant permits are processed by the Division. Operation permits are state-only (natural or synthetic minor), federally enforceable state operation permits (FESOP), or Title V (Chapter 62-213).
- IndustryOil & Gas air permittingProduction sites combine many small emission units, which makes equipment inventories and accurate potential-to-emit calculations central to choosing an authorization path.
- IndustryMidstream air permittingCompressor stations and gathering systems are typically engine- and compressor-driven, with dehydration and fugitive emissions as common sources.
- IndustryPower Generation air permittingPower generation permitting centers on combustion sources, with emissions driven by fuel type, capacity, and operating hours.
- IndustryMining & Aggregates air permittingAggregate operations are typically particulate-focused, with crushing, screening, conveying, and haul roads.
- IndustryWaste & Landfills air permittingLandfill gas collection and control is a central air topic for waste facilities.
- IndustryOther Industrial air permittingStart with an equipment inventory; most permitting decisions follow from the emission units on site.
- CalculatorFlaring CalculatorCombustion products from flares and enclosed combustors based on heat release.
- CalculatorVenting CalculatorConverts a measured or engineered vented gas volume to pollutant mass using gas composition.