An emissions inventory is a compilation of actual or estimated emissions of criteria and other air pollutants from both human-made (anthropogenic) and naturally occurring (biogenic) sources. DEC develops emissions inventories to comply with state requirements, federal Clean Air Act (CAA) requirements and New York's Climate Leadership and Community Protection Act (CLCPA). Emissions inventories are also a key component in State Implementation Plans (SIPs).
Sources of Air Pollution
- Point sources (large stationary)
- Non-point or Area sources (small stationary and area-wide sources)
- On-road mobile sources
- Non-road mobile sources
- Biogenic sources (naturally occurring)
- Volatile organic compounds (VOC)
- Nitrogen oxides (NOx)
- Carbon monoxide (CO)
- Particulate matter (fine PM2.5 and course PM10)
- Sulfur dioxide (SO2)
- Lead (Pb)
Hazardous Air Pollutants
Climate Pollutants (Greenhouse Gases)
- Carbon dioxide (CO2)
- Methane (CH4)
- Nitrous oxide (N2O)
- Sulfur hexafluoride (SF6)
- Perfluorocarbons (PFCs)
- Hydrofluorocarbons (HFCs)
- Nitrogen Trifluoride (NF3)
DEC collects point source emissions data by having "major" stationary sources submit an emissions statement report every year. These facilities are larger stationary sources and trigger the Title V requirements of Part 201. A list of New York State Title V facilities, and the air pollutants emitted from those facilities, is available at Open Data NY starting with 2010.
Examples of point sources:
- Oil and/or natural gas fired power plants
- Lead and aluminum smelters
- Large manufacturing facilities
- Institutional/Commercial boilers
Non-Point or Area Sources
Non-Point or Area sources are small stationary and area-wide source categories, including industrial, commercial, and residential sources, that generate emissions but do not meet the size requirements to be considered a "point" source. DEC develops a statewide area source emissions inventory every three years. With some exceptions, area source emissions are calculated by multiplying an established emissions factor (emissions per unit of activity) by the appropriate activity or activity surrogate to estimate emissions. Population is one of the more commonly used activity surrogates for area sources. Other activity data include the amount of gasoline sold in an area or employment by industry type.
Examples of area sources:
- Household paint and other coatings
- Agricultural feed lots
- Consumer products, such as deodorant and hair spray
- Small combustion sources, such as home heaters
- Gas stations
EPA area source information can be found at https://www.epa.gov/air-emissions-inventories/volume-3-area-sources-and-area-source-method-abstracts
Mobile Sources (On-Road)
Sources of on-road mobile emissions include cars, trucks, motorcycles, and other motor vehicles that can travel on public roadways. To estimate on-road mobile source emissions, the Motor Vehicle Emissions Simulator (MOVES) model is utilized to process New York specific inputs, including vehicle miles travelled and vehicle population. DEC conducts a statewide on-road mobile source emissions inventory every three years for the NEI and every year for New York's greenhouse gas inventory.
Examples of on-road mobile sources:
Mobile Sources (Non-Road)
Non-road vehicles do not typically operate on public roads or highways and are often referred to as off-road or off-highway vehicles. DEC uses EPA's NONROAD report from the MOVES model to estimate emissions for all non-road mobile source equipment except for airports, rail and commercial marine vessels (CMV). Emissions from airports are estimated by EPA using other approved emissions models and surveys; emissions from locomotives are estimated by EPA using actual survey and activity data from rail yards; and emissions from CMVs are estimated by EPA using data from local ports and the United States Department of Transportation Maritime Administration.
Examples of non-road mobile sources:
- Farm equipment
- Construction and mining equipment
- Lawn and garden equipment
- Aircraft and airport equipment
Sources of natural (biogenic) emissions usually include crops, trees, lawns and soils. Other sources include volcanic emissions, lightning, and sea salt.