skip navigation
New Hampshire Department of Environmental Services


The Air Resources Division of NHDES regulates and limits air emissions from a variety of sources within New Hampshire through a statewide permitting program. The New Hampshire Administrative Rules Governing the Control of Air Pollution (Rules) outline the permitting process and list sources that require permits for air emissions, either by overall source, specific device, or by pollutant. In addition, NHDES is responsible for implementing most Federal air pollution control regulations. The purpose of the permitting program is to achieve and maintain air quality standards throughout the state. The Rules include established standards (National Ambient Air Quality Standards or "NAAQS") for six criteria pollutants (ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide, particulate matter, and lead), as well as the basis for establishing ambient air limits for air toxic pollutants.

Sources of air emissions which require permits include point sources (major stationary commercial and industrial facilities), area sources (generally small , but numerous, stationary sources like dry cleaners and print shops), and devices (individual burners, furnaces, machines, etc.).

In addition to the specific sources/devices listed in the table, the rules contain conditions under which a source would be required to obtain a permit. Examples of these conditions include:

  • Sources choosing to limit their potential to emit by accepting enforceable permit conditions;
  • Sources at which documented and repeated violations occur of any of the applicable opacity or emission limits found in the Rules;
  • Sources at which documented and repeated violations of any NAAQS occur and the source is a significant contributor to the violation;
  • Sources subject to "New Source Review," a pollutant-specific program for new sources or modifications to sources which have emission levels above certain applicability thresholds;
  • Sources subject to National Emission Standards for Hazardous Air Pollutants (NESHAP) for source categories defined in federal regulations 40 CFR Parts 61 and 63;
  • Sources operating as treatment, storage or disposal facilities under the NH Hazardous Waste Rules;
  • Sources subject to the Rules governing Air Toxic Pollutants;
  • Sources subject to the Rules governing reasonably available control technology (RACT) for volatile organic compounds (VOCs) or nitrogen oxides (NOx);
  • Sources where a permit is required in order to achieve compliance with NAAQS;
  • Sources affected by or opting into the Acid Rain program under Title IV of the federal Clean Air Act Amendments of 1990; and
  • Sources defined in the Rules as "major sources," as determined by the type and amount of pollutant emitted from the source and the geographical location of the source (required by Title V of the federal Clean Air Act Amendments of 1990).
Devices and Sources Which Require Permits for Air Emissions
Device/Source Design Rating Fuel
Fuel Burning Device 10 million BTU/hr Natural Gas, LP Gas, #2 fuel oil
Fuel Burning Device 4 million BTU/hr #4 fuel oil
Fuel Burning Device 2 million BTU/hr coal, wood, #6 fuel oil, used oil
Internal Combustion Engine
(One or more at a source; design rating threshold is combined total of all engines)
1.5 million BTU/hr liquid fuel oil
10 million BTU/hr Natural Gas or LP Gas
Potential to emit > 25 tons per year of any single regulated air pollutant
Incinerator 1,000 lbs/hr Type 0, 1, 2, 3 waste
Incinerator 200 lbs/hr Type 4, 5, 6, 7 waste
Stationary Source, Area Source, or Device Total actual photochemically-reactive VOC emissions 10 tons per year
Aboveground, Vertical, VOC Storage Tank Capacity 40,000 gallons containing VOCs with a true vapor pressure 1.52 psia at 60 F
Device for loading tank trucks with gasoline at a gasoline terminal Design throughput 20,000 gal/day
Woodworking Device employing pneumatic transfer system, using a cyclone but no baghouse, for collecting any amount of sander dust Wood waste collection rate 20 tons/yr
Pneumatic dust transfer equipment used to convey materials, other than wood waste, into bins or silos, and not using a baghouse or filter for controlling dust
Fixed non-metallic mineral processing plant or coal crusher Design throughput 25 tons/hr
Portable sand and gravel or crushed stone plant or coal crusher Design throughput 150 tons/hr

The Air Resources Division issues four types of permits: Temporary Permits, State Permits to Operate, General State Permits, and Title V Operating Permits.

Temporary Permits
A temporary permit is issued prior to the commencement of construction or installation of any new or modified source or device. A temporary permit is issued for a period no longer than 18 months and contains terms and conditions establishing the parameters under which the source or device is constructed or operated. A temporary permit is issued to sources or devices based on several criteria including the source or device type, design ratings, levels of production, and annual emission levels. A temporary permit is the first step toward obtaining either a state permit to operate or a Title V operating permit.

State Permits to Operate
A state permit to operate is issued prior to the operation of any new or modified source or device, for a period not to exceed 5 years. A state permit to operate contains the emission limits and any other conditions the source is required to meet to ensure that the operation of the source will not result in a violation of any air quality standard or regulation.

State permits to operate are issued to sources or devices which:

  • were required to hold temporary permits;
  • are not subject to the Title V operating permitprogram, or
  • are choosing to limit their potential emissions to a level below the major source threshold which would trigger a Title V operating permit (called a "synthetic minor source").

General State Permits
A General State Permit is issued for a specific source category for a period not to exceed five years. A source that falls under one of the General State Permit categories may choose to comply with the terms and conditions of the General State Permit instead of obtaining a State Permit to Operate. A source seeking to operate under a General State Permit needs to submit a registration package. Forms for the General State Permit registration are listed with the Air Permit Application Forms.

Title V Operating Permits
Title V Operating Permits are issued to sources, called "major sources," which emit or have the potential to emit the following pollutants at the levels specified:

  • 10 tons per year (TPY) or more of any one hazardous air pollutant;
  • 25 TPY or more of any combination of hazardous air pollutants;
  • 100 TPY or more of NOx for sources located in Belknap, Carroll, Cheshire, Coos, Grafton, and Sullivan Counties;
  • 50 TPY or more of NOx for sources located in Hillsborough, Merrimack, Rockingham, and Strafford Counties;
  • 50 TPY or more of VOCs; or
  • 100 TPY or more of any criteria pollutant (e.g. sulfur dioxide).

Other sources, including area sources, may also be required to obtain Title V Operating Permits if they are subject to federal requirements relating to new source performance standards, hazardous air pollutants, or acid rain control.

The Title V operating permit program, effective June 30, 1995, is a requirement of Title V (Permits) of the federal Clean Air Act Amendents of 1990. Title V operating permits are issued for a five-year period.

NH Department of Environmental Services | 29 Hazen Drive | PO Box 95 | Concord, NH 03302-0095
(603) 271-3503 | TDD Access: Relay NH 1-800-735-2964 | Hours: M-F, 8am-4pm

copyright 2017. State of New Hampshire