Carbon Monoxide Maintenance Plan
 

Greeley 

Technical Support Document
 

Emission Inventory
 

December 17, 2009 

Colorado Department of Public Health and Environment 

Air Pollution Control Division 

4300 Cherry Creek Drive South 

Denver, Colorado 80246 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

Table of Contents 

1. EMISSION INVENTORY METHODOLOGY 1
 

2. 2007 EMISSION INVENTORY SUMMARY 2
 

3. REFERENCES 3
 

December 17, 2009 

co Mamtenance Plan for Greeley - Technical Support Document - EmiSSion Inventory 

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Colorado Department of Public Health and Environment / Air Pollution Control Division 

1. Emission Inventory Methodology 

The Air Pollution Control Division (APCD) developed the 2007 emission inventories in the 

"Carbon Monoxide Maintenance Plan for Greeley" using U.S: Envirorunental Protection Agency 

(EPA) approved emissions modeling methods, including EPA's MOBILE6 model and local VMT 

data for on-road mobile source emissions, EPA's non-road model, local demographic information 

for area and off-road sources, and reported actual emissions for point sources. The inventory 

represents average daily winter emissions. The MOBILE6 and non-road model inputs represent 

these average daily winter conditions. Heating and wood burning emissions were apportioned 

from annual emission estimates by heating degree day data from the Western Regional Climate 

Center. Other source categories were apportioned from annual to daily by dividing by 365. 

Highway mobile source emissions are from the EPA model MOBILE6, an emission factor model 

for predicting gram per mile emissions of Hydrocarbons (HC), Carbon Monoxide (CO), Nitrogen 

Oxides (NUx), Carbon Dioxide (C02), Particulate Matter (PM), and toxics from cars, trucks, and 

motorcycles under various conditions. 

Non-road source emissions are from the EPA Non-Road Model. This model includes the impact of 

future controls on non-road engines, which is used in equipment such as lawn and garden 

equipment and construction equipment. 

Area source emissions (including heating, construction, railroads, etc.) are from the 2002 EPA 

National Emissions Inventory (NEI) and grown to 2007 by population growth from data from the 

State. For more documentation for these categories, refer to the NEI documentation (EPA, 2008). 

Under Air Quality Control Commission Regulation No.3, the APCD requires any source that 

emits two tons per year or greater to submit an Air Pollutant Emission Notice (APEN) (APCD, 

2008). This means that sources that emit less than two tons per year are not necessarily accounted 

for in an emissions inventory. The point source emissions for Greeley were obtained from this 

tracking system. The emission estimates are made using a variety of methodologies. Data from 

source-specific emission tests, or continuous emission monitors are preferable, but not always 

available. The EPA has developed a variety of emission factors to estimate emissions as well. 

Emission factors are frequently the best or only method available for estimating emissions. 

Oil and Gas Emissions (O&G area and O&G point) from oil and gas exploration and development 

sources are based on the 2006 and 2010 Independent Petroleum Association of Mountain States 

(IPAMS) Inventory and the Norwest Corporation Study of oil and gas growth from 2010 to 2020 

for the DJ Basin. 

December 17, 2009 

CO Maintenance Plan/or Greeley - Techmcal Support Document - EmiSSIOn Inventory 

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Colorado Department of Public Health and Environment / Air Pollution Control Division 

2. 2007 Emission Inventory Summary 

This section presents the 2007 emission inventories for the maintenance plan. 

Table 1. 2007 CARBON MONOXIDE Emission Inventory (tons per day). 

CO 

Bio entc 0.00 

Commercial Cookln 0.05 

Fuel Combustion 0.55 

Hi hwa Vehicles 55.36 

Non O&G POInt Sources 0.58 

Non-Road 17.81 

O&G area 0.02 

O&G Oint 0.03 

Railroads 0.04 

Structure Fires 0.03 

Woodburnm 6.75 

81.23 

SWIFT BEEF COMPANY 0.05
 

NORTHERN CO MEDICAL CTR 0.01 

NORTHERN CO CREMATORY INC 0.00 

THERMO POWER & ELEC INC 0.0 

SCHULTE INVESTMENTS WAS ELSRO INC 0.00 

CITY OF GREELEY WATER POLLUT CONTROL FAC 0.00 

MEADOW GOLD DAIRY 0.01 

THERMO GREELEY INC 0.27 

LAFARGE WEST, INC. - 35TH AVE PLANT 0.06 

UNIV OF NORTHERN COLORADO 0.10 

HUMANE SOCIETY OF WELD COUNTY 0.00 

AGGREGATE INDUSTRIES - WCR, INC. 0.03 

TOTA 0.58 

December 17, 2009 

CO MaIntenance Planfor Greeley - TechnIcal Support Document - EmIssIOn Inventory 

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Colorado Department of Public Health and Environment / Air Pollution Control Division 

3. References 

APCD, 2008. Air Quality Control Commission Regulation Number 3. Stationary Source 

Permitting and Air Pollutant Emission Notice Requirements. 5 CCR 1001-5. 

< http://www.cdphe.state.co.us/regulations/airregs/l 001 03stationarysourcepermitting.pdf > 

U.S. EPA, 2008. "2002 National Emissions Inventory Data & Documentation." 

< http://www.epa.gov/ttn/chief/net/2002inventory.html#documentation> 

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