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Facility Emissions Inventory Calculator

Preliminary aggregation of user-entered emissions with Title V, PSD, AP-42, HAP, state-rule, and permit-method warnings

Free facility emissions inventory screening calculator. Enter already-calculated emissions from multiple sources (boilers, generators, process equipment, coating lines) and get facility-wide totals for NOx, SO2, VOC, CO, PM10, and PM2.5 in tons per year. The app identifies dominant source rows and local screening flags, but it does not choose emissions methods or determine Title V, PSD, NSR, HAP, GHG, state inventory, or permit applicability.

Pro Tip: Before using the totals for decisions, verify whether the inventory must include point, fugitive, area, emergency, startup, shutdown, malfunction, insignificant/de minimis, HAP, GHG, or permit-specific source categories. The app cannot infer source-boundary, attainment, netting, synthetic-minor, PAL, or state-program treatment.

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Facility Emissions Inventory Calculator
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How It Works

  1. Add Emission Sources

    Enter each source by name after deciding which units belong in the same facility inventory. Treat facility-boundary and common-control decisions as permit/source questions, not calculator decisions.

  2. Enter Emissions Per Pollutant

    For each source, enter annual emissions in tons per year from the accepted method: permit factors, source tests, CEMS, AP-42, material balances, production records, or state inventory instructions.

  3. Review Facility Totals

    The calculator sums all sources per pollutant and applies local screening labels for the 100 tpy default Title V screen and listed PSD significant-emission-rate screens. These are not applicability decisions.

  4. Identify Dominant Sources

    The breakdown shows which source contributes the most to each pollutant. Use that as a planning clue before reviewing method quality, controls, permit limits, and agency reporting rules.

Built For

  • Environmental managers drafting source lists before state inventory review
  • Consultants checking arithmetic in facility-wide emissions worksheets
  • Plant engineers identifying which source rows dominate a pollutant total
  • Operations staff comparing user-entered emissions against local screening flags
  • Corporate teams reviewing preliminary source profiles before qualified compliance review

Assumptions

  • User-entered values represent annual emissions in tons per year.
  • All entered sources are treated as a single facility boundary for planning only.
  • The 100 tpy Title V value is a default screen; lower nonattainment, HAP, source-category, permit, and state thresholds may apply.

Limitations

  • Does not calculate emissions from raw inputs - users must provide pre-calculated tpy values.
  • Does not include HAP-specific tracking or HAP major source thresholds.
  • Does not account for fugitive emissions unless manually entered.
  • Does not determine PSD/NSR/NNSR applicability, netting, baseline actual emissions, projected actual emissions, synthetic-minor limits, or PAL treatment.
  • State-specific inventory formats and reporting requirements are not addressed.

References

  • Clean Air Act Section 502(a) - Title V Permit Program Applicability
  • 40 CFR Part 70 - State Operating Permit Programs
  • EPA Emission Inventory Improvement Program (EIIP) Guidance
  • State-specific emission inventory reporting guidance documents

Frequently Asked Questions

The required source list depends on the permit, state instructions, source category, and reporting program. A complete review may need point, fugitive, area, emergency, startup, shutdown, malfunction, insignificant/de minimis, HAP, GHG, and mobile/onsite treatment. The app only totals rows you enter.
EPA lists 100 tpy as the default major-source screen for an air pollutant, with lower nonattainment thresholds and 10/25 tpy HAP thresholds. Actual applicability depends on actual versus potential emissions, source category, attainment status, enforceable limits, state program rules, and permit review.
No. The app shows listed PSD significant-emission-rate screens for common pollutants. PSD/NSR applicability requires major-source status, project emissions increase, baseline actual emissions, projected actual emissions, contemporaneous netting, source category, location, and permitting authority review.
Disclaimer: This calculator provides preliminary arithmetic aggregation only. It does not calculate emissions from raw activity data or determine Title V, PSD, NSR, NNSR, HAP, GHG, state inventory, synthetic-minor, PAL, permit-limit, or agency-approved reporting status. Verify every value and method with current permits, source data, state instructions, EPA/eCFR sources, and qualified environmental/compliance review.

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