Common Mistakes
by Carrie Schroeder
Emission Factors
Where did they come from?
How old are they?
If you changed it in your spreadsheet, make sure to change it in Redbud
Document where you got the emission factor
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Control Efficiencies
Is yours included in the emission factor you’re using?
Then don’t forget to check the box!
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Controls
Listing controls and efficiencies that do not apply to that pollutantFabric filters and baghouses only control PM
Catalytic converters control CO, VOCs and/or NOx
Catalytic oxidizers control CO and VOCs
4
Units
Double check that the units in Redbud are still accurate
Check:process rate units
emission factor units
We can’t replicate your emissions if the units are incorrect
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Hazardous Air Pollutants (HAPs)
Are they in your VOCs?
Speciate your HAPs out of your VOCs
We especially saw this error on compressor engines
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Stack Parameters
If flow rate = 0 then list the unit as a fugitive
Cannot replicate flow rate and gas exit velocity calculation
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Stack parametersEquation:
Gas Exit Velocity = flow rate (acfm) ÷
(∏ x r2 x 60)
OR
Flow rate (acfm) = exit gas velocity x
(∏ x r2 x 60)
acfm= actual cubic feet per minute
For non-round stacks
Diameter = 1.128 x √(length x width)8
Stack Parameters
OR
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Reporting/Not Reporting
Emissions reported but have 0 for process rate and/or 0 for annual hours
OR
Process rate reported and/or annual hours reported but emissions are 0 and trace boxes are not checked
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Reporting Same Values
If you have the same annual process rate, annual hours, and emissions for 2 years in a row then you will get flagged in our QC program
Usually incorrect, so please don’t just re-enter last years data
Some correct situations might be emergency generators, fire pumps, and process tank heaters
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Inconsistent Increase/Decrease in Emissions
You will get flagged if:Annual process rate and hours vary slightly
from previous year to current year, but emissions decrease or increase greatly
And calculation method, controls, emission factor, and emission factor units have not changed
If you legitimately fall into this situation then please make an emission unit note explaining why
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Why Your Inventory Is Important
Missing or incorrect release point data lead to errors in geographical location of emissions and impacts photochemical modeling and health risk assessments
Missing or incorrect hours and season fractions lead to errors in temporal distribution of emissions
Errors in SCC and SIC impact control strategy development and attainment plans
Missing or incorrect control equipment data impacts rule development
Good data leads to effective air quality regulation13
Any Questions?
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