Emissions Inventory Overview–Part 1 Melinda Ronca-Battista, ITEP
Overview • What is an Emissions Inventory and why do we need one? • Part 1 • Types of EIs • Pollutants • Sources • Part 2 • Quantifying emissions • Types of data collected • Reporting
What is an Emissions Inventory? Listing of sources of estimatedair pollutant emissions in geographic area during specific time period
What are Emission Sources? Non-Road Mobile Sources Non-Point Sources (Area Sources) Point Sources On-Road Mobile Sources Based on EPA
How are EI data used? • Air quality management tool • Collect baseline data • Develop & track emissions control and management strategies • Regulations development • Air quality modeling and assessment • Permits • Do you have facilities that need permits? • Conditions (potential to emit) • Fees • Emissions trading • Regulatory compliance
Inventory Steps • Source identification • Phonebook/windshield survey • NEI data, previous EIs • Planning! • Inventory Preparation Plan (IPP) • Quality Assurance Project Plan (QAPP) • Collect data • From sources, permits, questionnaires, etc.
Inventory Steps (cont.) • Calculate and analyze data (TEISS, Excel, GIS, etc.) • Report data and present results • Internal: tribal council, community • External: EPA project officer, National Emissions Inventory (NEI)
Level of Detail • Simple summary: Small reservation, few on-reservation sources • Compiled from existing data sources • Includes only large sources • Comprehensive accounting: Large reservation, many and/or large sources • Large on-reservation sources–permitting • “Problem” emissions (agricultural burning, small industries, road dust, traffic emissions)
What are Emissions? • Criteria Pollutants • Particle matter: PM10 and PM2.5 • Nitrogen oxides: NOx • Sulfur dioxide: SO2 • Carbon monoxide: CO • Lead: Pb • Ozone precursors • Ammonia: NH3 • Volatile Organic Compounds: VOCs • HAPs (Air Toxics) • 187 toxic, carcinogenic compounds without regulated standards
Criteria Pollutants • What about Ozone? • Ozone is not emitted directly by sources • EIs inventory ozone precursors • VOCs • NOx • Both react with sunlight to form ozone. • NOx and VOCs get inventoried, but not ozone itself
HAPs (Air Toxics) • 187 compounds listed in CAA including • Mercury (power plants, coal-fired) • Perchloroethylene (dry cleaning) • Benzene (gasoline) • Chloroform (chlorination plants, paper mills) • Methyl Isocyanate (pesticide manufacturing) • Release at Bhopal, India, killed 4,000 people • The list goes on….
Types of Sources • Point sources = Stationary sources • Area sources = Non-Point sources • Mobile sources • On-Road (cars, motorcycles, trucks, buses) • Non-Road (trains, heavy equip.) • Biogenic sources
What is a Point Source? Individual, stationary source releasing pollutants to atmosphere Quantities above emission threshold Emission thresholds vary according to type of pollutant and non-attainment area classification for criteria pollutants See Air Emission Reporting Requirement (AERR) for more detail
What is a Point Source? (cont.) • AERR reporting thresholds are quite high. Compared to Potential to Emit. • Many states have lower thresholds • Consider using state thresholds to define your reservation’s point sources • Makes EI compatible with others in your area • Get a more detailed listing of sources • Example: Busy gas station can be point source under state thresholds, but not EPA’s
Point Source Characteristics • Large, stationary sources • Manufacturing or production plants • Power plants, refineries • Large, industrial facilities • One point source facility can have emissions from • Smoke stacks • Units within directed to stacks • Fugitive sources within plant
Area (Non-Point) Sources • Stationary sources that emit • Less than point source threshold • Smaller emitters, but numerous • Often have fugitive (uncontrollable) emissions • Tend to be sources like • Gasoline stations • Dry cleaners • Auto body/paint shops • Unpaved roads
Wildfires and prescribed burning E.g., agricultural field burning Now inventoried as EVENTS Other area source examples Residential wood combustion Residential combustion of household waste (backyard burning) Other Area Sources
On-Road Mobile Sources • Vehicles found on roads and highways (e.g., cars, trucks, buses, motorcycles) • 20 volatile organic compounds (VOCs) and metals quantified (Urban Air Toxics) • Diesel particulate matter and diesel exhaust organic gases also quantified
Non-Road Mobile Sources • Mobile sources not found on roads and highways (e.g., airplanes, trains, lawn mowers, construction vehicles, farm machinery) • 2/4 stroke engines • aircraft • locomotives • commercial marine vessels • hobby engines
Non-Road Mobile Sources • Note about aircraft • ALL airports are now considered point sources in the NEI • If you have airports on your reservation, check the most recent NEI data. Use it in your EI • UNLESS you have more accurate data.
Biogenic Sources • Naturally occurring emissions • Vegetation: Trees, shrubs, grasses • Microbial: Soil bacteria, termites • EPA estimates these emissions on a county level for entire country… • …so you don’t have to