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National Clean Diesel Campaign (NCDC)

Working Together for Cleaner Air

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Diesel Emissions Quantifier (DEQ)

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The DEQ is an interactive tool that evaluates clean diesel projects and options for medium-and heavy-heavy duty diesel vehicles by estimating emission reductions, cost effectiveness, and health benefits. This quantifier was developed for users with little or no modeling experience.

DEQ results can be downloaded to a spreadsheet that provides the following information:

  • Estimates of baseline emissions (annual and lifetime)
  • Estimates of emission reductions, cost effectiveness and health benefits (annual and lifetime)
  • Comparison of emission reductions, cost effectiveness and health benefits for different emission control strategies (annual and lifetime)
  • Assistance to EPA grantees in developing data reports for submission to EPA

The DEQ may not be used for State Implementation Plans (SIPs) and Conformity. Please consult your EPA Regional Office or relevant SIP and conformity guidance documents.

The DEQ does not currently provide estimates for

  • light-heavy duty or non-heavy duty vehicles
  • non-diesel engines
  • pre-1980 engines or ocean going vessels
  • CO2 and other greenhouse gases (GHG) reductions from retrofit devices or engine replacements
  • health benefits from NOx, HC, and CO reductions
  • black carbon reductions from retrofit devices or engine replacements
  • fuel saving benefits for nonroad engines with idle reduction technologies or engine replacements

Before using the DEQ, please also read

  • Input Checklist to learn what inputs you'll need, some basic terms and how to get the most accurate results
  • Results and Outputs to learn how to download and interpret your results

Other Emission Reduction Calculators

Users with air quality modeling experience may wish to use one of EPA’s more technical models for quantifying the benefits of retrofit projects.

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