{"schema_version":1,"layer":"air","reviewed_on":"2026-10-28","coverage_note":"Generator counts documented in selected permits, not a complete state or national count. A construction or operation permit does not prove equipment installation, operating hours, measured emissions or a data center opening.","items":[{"id":"air-mt-permit-framework-20261025","kind":"permit_context","state_codes":["mt"],"subject":"Montana construction and operating permit framework boundaries","scope":"Montana DEQ New Facilities, Permitted Sources, MAQP and TitleV FAQ reviewed. Linked current ARM rules and registration programs not fully reviewed. Numeric thresholds and individual applicability not determined.","fields":{"mt_permit_framework_basis":{"value":"Agency guidance distinguishes Montana Air Quality Permit construction authorization from TitleV operating permit requirements.","source_ids":["mt-air-assistance-20261025"],"locator":"New Facilities; MAQP and TitleV FAQ","scope":"Montana DEQ New Facilities, Permitted Sources, MAQP and TitleV FAQ reviewed. Linked current ARM rules and registration programs not fully reviewed. Numeric thresholds and individual applicability not determined."},"status":{"value":"program","source_ids":["mt-air-assistance-20261025"],"locator":"New Facilities; MAQP and TitleV FAQ","scope":"Montana DEQ New Facilities, Permitted Sources, MAQP and TitleV FAQ reviewed. Linked current ARM rules and registration programs not fully reviewed. Numeric thresholds and individual applicability not determined."},"mt_construction_boundary":{"value":"Where an MAQP is required, agency says apply for and receive it before construction or modification. General guidance does not establish any individual facility approval or installation.","source_ids":["mt-air-assistance-20261025"],"locator":"New Facilities; MAQP and TitleV FAQ","scope":"Montana DEQ New Facilities, Permitted Sources, MAQP and TitleV FAQ reviewed. Linked current ARM rules and registration programs not fully reviewed. Numeric thresholds and individual applicability not determined."},"mt_term_boundary":{"value":"Agency says MAQPs do not expire and directs existing facility changes to separate review. TitleV operating permits require renewal every5years. Neither statement establishes perpetual compliance or permission for later changes.","source_ids":["mt-air-assistance-20261025"],"locator":"New Facilities; MAQP and TitleV FAQ","scope":"Montana DEQ New Facilities, Permitted Sources, MAQP and TitleV FAQ reviewed. Linked current ARM rules and registration programs not fully reviewed. Numeric thresholds and individual applicability not determined."},"mt_registration_boundary":{"value":"Registration programs apply to specified industry categories. Oil and gas registration or construction timing is not generalized to data centers or emergency generators.","source_ids":["mt-air-assistance-20261025"],"locator":"New Facilities; MAQP and TitleV FAQ","scope":"Montana DEQ New Facilities, Permitted Sources, MAQP and TitleV FAQ reviewed. Linked current ARM rules and registration programs not fully reviewed. Numeric thresholds and individual applicability not determined."},"mt_pte_boundary":{"value":"Potential emissions determine applicability, not measured actual emissions. Numeric thresholds in the agency summary were not independently checked against current rules and are not adopted here.","source_ids":["mt-air-assistance-20261025"],"locator":"New Facilities; MAQP and TitleV FAQ","scope":"Montana DEQ New Facilities, Permitted Sources, MAQP and TitleV FAQ reviewed. Linked current ARM rules and registration programs not fully reviewed. Numeric thresholds and individual applicability not determined."},"issued_permit":{"value":null,"source_ids":["mt-air-assistance-20261025"],"locator":"New Facilities; MAQP and TitleV FAQ","scope":"Montana DEQ New Facilities, Permitted Sources, MAQP and TitleV FAQ reviewed. Linked current ARM rules and registration programs not fully reviewed. Numeric thresholds and individual applicability not determined.","unknown_reason":"No individual permit or facility determination reviewed."}}},{"id":"air-egrid-state-2023-mt","subject":"Montana historical2023 electricity-generation emissions","kind":"emissions_context","state_codes":["mt"],"scope":"EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence.","fields":{"status":{"value":"historical","source_ids":["epa-egrid2023-states-rev2"],"scope":"EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence.","locator":"ST23 Data Year column"},"egrid_report_year":{"value":"2023","source_ids":["epa-egrid2023-states-rev2"],"scope":"EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence.","locator":"ST23 YEAR column"},"egrid_state_fips":{"value":"30","source_ids":["epa-egrid2023-states-rev2"],"scope":"EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence.","locator":"ST23 FIPSST column"},"egrid_state_basis":{"value":"EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence.","source_ids":["epa-egrid2023-states-rev2"],"scope":"EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence.","locator":"ST23 labels,codes,units and review scope"},"egrid_annual_net_generation":{"value":26895758.013,"source_ids":["epa-egrid2023-states-rev2"],"scope":"EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence.","locator":"ST23 MT row 29, STNGENAN (State annual net generation (MWh))","unit":"MWh","measurement_role":"reported_egrid_annual_net_generation","source_token":"26895758.013"},"egrid_annual_nox_emissions":{"value":11734.543,"source_ids":["epa-egrid2023-states-rev2"],"scope":"EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence.","locator":"ST23 MT row 29, STNOXAN (State annual NOx emissions (tons))","unit":"tons","measurement_role":"reported_egrid_annual_nox_emissions","source_token":"11734.543"},"egrid_annual_so2_emissions":{"value":10875.186,"source_ids":["epa-egrid2023-states-rev2"],"scope":"EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence.","locator":"ST23 MT row 29, STSO2AN (State annual SO2 emissions (tons))","unit":"tons","measurement_role":"reported_egrid_annual_so2_emissions","source_token":"10875.186"},"egrid_annual_co2_emissions":{"value":14203204.304,"source_ids":["epa-egrid2023-states-rev2"],"scope":"EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence.","locator":"ST23 MT row 29, STCO2AN (State annual CO2 emissions (tons))","unit":"tons","measurement_role":"reported_egrid_annual_co2_emissions","source_token":"14203204.304"},"egrid_nox_total_output_rate":{"value":0.873,"source_ids":["epa-egrid2023-states-rev2"],"scope":"EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence.","locator":"ST23 MT row 29, STNOXRTA (State annual NOx total output emission rate (lb/MWh))","unit":"lb per MWh","measurement_role":"reported_egrid_nox_total_output_rate","source_token":"0.873"},"egrid_so2_total_output_rate":{"value":0.809,"source_ids":["epa-egrid2023-states-rev2"],"scope":"EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence.","locator":"ST23 MT row 29, STSO2RTA (State annual SO2 total output emission rate (lb/MWh))","unit":"lb per MWh","measurement_role":"reported_egrid_so2_total_output_rate","source_token":"0.80900000000000005"},"egrid_co2_total_output_rate":{"value":1056.167,"source_ids":["epa-egrid2023-states-rev2"],"scope":"EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence.","locator":"ST23 MT row 29, STCO2RTA (State annual CO2 total output emission rate (lb/MWh))","unit":"lb per MWh","measurement_role":"reported_egrid_co2_total_output_rate","source_token":"1056.1669999999999"},"egrid_annual_ch4_emissions_lb":{"value":3133348.953,"source_ids":["epa-egrid2023-states-rev2"],"scope":"Historical2023 EPA eGRID ST23 source-reported CH4,N2O,CO2 equivalent and ozone-season NOx context. Annual CH4/N2O totals are source lbs;CO2 equivalent total is source tons;total output rates are lb/MWh. CO2 equivalent differs from raw CO2; no global-warming-potential factor assumed or recomputed,no pounds/tons/metric-tonne conversion. Source-defined ozone-season NOx is not full-year NOx or an ambient ozone concentration. Annual and seasonal rates and totals remain separate,not summed across scopes. No marginal,facility,health-risk or attributable data center emissions inference.","locator":"ST23 MT row 29, STCH4AN (State annual CH4 emissions (lbs))","unit":"lbs","measurement_role":"reported_egrid_annual_ch4_emissions","source_token":"3133348.9530000002"},"egrid_annual_co2e_emissions":{"value":14307487.313,"source_ids":["epa-egrid2023-states-rev2"],"scope":"Historical2023 EPA eGRID ST23 source-reported CH4,N2O,CO2 equivalent and ozone-season NOx context. Annual CH4/N2O totals are source lbs;CO2 equivalent total is source tons;total output rates are lb/MWh. CO2 equivalent differs from raw CO2; no global-warming-potential factor assumed or recomputed,no pounds/tons/metric-tonne conversion. Source-defined ozone-season NOx is not full-year NOx or an ambient ozone concentration. Annual and seasonal rates and totals remain separate,not summed across scopes. No marginal,facility,health-risk or attributable data center emissions inference.","locator":"ST23 MT row 29, STCO2EQA (State annual CO2 equivalent emissions (tons))","unit":"tons","measurement_role":"reported_egrid_annual_co2e_emissions","source_token":"14307487.312999999"},"egrid_annual_n2o_emissions_lb":{"value":455970.756,"source_ids":["epa-egrid2023-states-rev2"],"scope":"Historical2023 EPA eGRID ST23 source-reported CH4,N2O,CO2 equivalent and ozone-season NOx context. Annual CH4/N2O totals are source lbs;CO2 equivalent total is source tons;total output rates are lb/MWh. CO2 equivalent differs from raw CO2; no global-warming-potential factor assumed or recomputed,no pounds/tons/metric-tonne conversion. Source-defined ozone-season NOx is not full-year NOx or an ambient ozone concentration. Annual and seasonal rates and totals remain separate,not summed across scopes. No marginal,facility,health-risk or attributable data center emissions inference.","locator":"ST23 MT row 29, STN2OAN (State annual N2O emissions (lbs))","unit":"lbs","measurement_role":"reported_egrid_annual_n2o_emissions","source_token":"455970.75599999999"},"egrid_ozone_season_nox_total_output_rate":{"value":0.774,"source_ids":["epa-egrid2023-states-rev2"],"scope":"Historical2023 EPA eGRID ST23 source-reported CH4,N2O,CO2 equivalent and ozone-season NOx context. Annual CH4/N2O totals are source lbs;CO2 equivalent total is source tons;total output rates are lb/MWh. CO2 equivalent differs from raw CO2; no global-warming-potential factor assumed or recomputed,no pounds/tons/metric-tonne conversion. Source-defined ozone-season NOx is not full-year NOx or an ambient ozone concentration. Annual and seasonal rates and totals remain separate,not summed across scopes. No marginal,facility,health-risk or attributable data center emissions inference.","locator":"ST23 MT row 29, STNOXRTO (State ozone season NOx total output emission rate (lb/MWh))","unit":"lb per MWh","measurement_role":"reported_egrid_ozone_season_nox_total_output_rate","source_token":"0.77400000000000002"},"egrid_extended_basis":{"value":"Historical2023 EPA eGRID ST23 source-reported CH4,N2O,CO2 equivalent and ozone-season NOx context. Annual CH4/N2O totals are source lbs;CO2 equivalent total is source tons;total output rates are lb/MWh. CO2 equivalent differs from raw CO2; no global-warming-potential factor assumed or recomputed,no pounds/tons/metric-tonne conversion. Source-defined ozone-season NOx is not full-year NOx or an ambient ozone concentration. Annual and seasonal rates and totals remain separate,not summed across scopes. No marginal,facility,health-risk or attributable data center emissions inference.","source_ids":["epa-egrid2023-states-rev2"],"scope":"Historical2023 EPA eGRID ST23 source-reported CH4,N2O,CO2 equivalent and ozone-season NOx context. Annual CH4/N2O totals are source lbs;CO2 equivalent total is source tons;total output rates are lb/MWh. CO2 equivalent differs from raw CO2; no global-warming-potential factor assumed or recomputed,no pounds/tons/metric-tonne conversion. Source-defined ozone-season NOx is not full-year NOx or an ambient ozone concentration. Annual and seasonal rates and totals remain separate,not summed across scopes. No marginal,facility,health-risk or attributable data center emissions inference.","locator":"ST23 field labels,report year and annual-versus-ozone-season units"},"egrid_ozone_season_nox_emissions":{"value":4196.937,"source_ids":["epa-egrid2023-states-rev2"],"scope":"Historical2023 EPA eGRID ST23 source-reported CH4,N2O,CO2 equivalent and ozone-season NOx context. Annual CH4/N2O totals are source lbs;CO2 equivalent total is source tons;total output rates are lb/MWh. CO2 equivalent differs from raw CO2; no global-warming-potential factor assumed or recomputed,no pounds/tons/metric-tonne conversion. Source-defined ozone-season NOx is not full-year NOx or an ambient ozone concentration. Annual and seasonal rates and totals remain separate,not summed across scopes. No marginal,facility,health-risk or attributable data center emissions inference.","locator":"ST23 MT row 29, STNOXOZ (State ozone season NOx emissions (tons))","unit":"tons","measurement_role":"reported_egrid_ozone_season_nox_emissions","source_token":"4196.9369999999999"},"egrid_co2e_total_output_rate":{"value":1063.921,"source_ids":["epa-egrid2023-states-rev2"],"scope":"Historical2023 EPA eGRID ST23 source-reported CH4,N2O,CO2 equivalent and ozone-season NOx context. Annual CH4/N2O totals are source lbs;CO2 equivalent total is source tons;total output rates are lb/MWh. CO2 equivalent differs from raw CO2; no global-warming-potential factor assumed or recomputed,no pounds/tons/metric-tonne conversion. Source-defined ozone-season NOx is not full-year NOx or an ambient ozone concentration. Annual and seasonal rates and totals remain separate,not summed across scopes. No marginal,facility,health-risk or attributable data center emissions inference.","locator":"ST23 MT row 29, STC2ERTA (State annual CO2 equivalent total output emission rate (lb/MWh))","unit":"lb per MWh","measurement_role":"reported_egrid_co2e_total_output_rate","source_token":"1063.921"},"egrid_ch4_total_output_rate":{"value":0.116,"source_ids":["epa-egrid2023-states-rev2"],"scope":"Historical2023 EPA eGRID ST23 source-reported CH4,N2O,CO2 equivalent and ozone-season NOx context. Annual CH4/N2O totals are source lbs;CO2 equivalent total is source tons;total output rates are lb/MWh. CO2 equivalent differs from raw CO2; no global-warming-potential factor assumed or recomputed,no pounds/tons/metric-tonne conversion. Source-defined ozone-season NOx is not full-year NOx or an ambient ozone concentration. Annual and seasonal rates and totals remain separate,not summed across scopes. No marginal,facility,health-risk or attributable data center emissions inference.","locator":"ST23 MT row 29, STCH4RTA (State annual CH4 total output emission rate (lb/MWh))","unit":"lb per MWh","measurement_role":"reported_egrid_ch4_total_output_rate","source_token":"0.11600000000000001"},"egrid_n2o_total_output_rate":{"value":0.017,"source_ids":["epa-egrid2023-states-rev2"],"scope":"Historical2023 EPA eGRID ST23 source-reported CH4,N2O,CO2 equivalent and ozone-season NOx context. Annual CH4/N2O totals are source lbs;CO2 equivalent total is source tons;total output rates are lb/MWh. CO2 equivalent differs from raw CO2; no global-warming-potential factor assumed or recomputed,no pounds/tons/metric-tonne conversion. Source-defined ozone-season NOx is not full-year NOx or an ambient ozone concentration. Annual and seasonal rates and totals remain separate,not summed across scopes. No marginal,facility,health-risk or attributable data center emissions inference.","locator":"ST23 MT row 29, STN2ORTA (State annual N2O total output emission rate (lb/MWh))","unit":"lb per MWh","measurement_role":"reported_egrid_n2o_total_output_rate","source_token":"1.7000000000000001E-2"}}},{"id":"air-eia-state-emissions-2025-mt","kind":"emissions_context","subject":"Montana historical power and useful thermal emissions2025 and2024","state_codes":["mt"],"scope":"EIA Table9.5 historical state2025 and2024 emissions estimates from energy consumption at conventional power and combined-heat-and-power plants. Includes electricity generation AND production of useful thermal output,not electricity-only emissions. Source unit is thousand metric tons,not eGRID source tons,pounds,CO2equivalent or emission intensity. Source CO2,SO2 and NOx are distinct pollutants,not summed as one climate measure. Displayed zero values may represent small values rounded to zero;no absence or zero-emissions certification. Retain displayed HTML precision;source says Excel cells provide additional precision,not adopted here. No direct eGRID trend or data center allocation,marginal emissions,ambient concentration,health risk,permit compliance,current2026 activity or Native facility joins.","fields":{"status":{"value":"historical","source_ids":["eia-epa2025-state-emissions"],"scope":"EIA Table9.5 historical state2025 and2024 emissions estimates from energy consumption at conventional power and combined-heat-and-power plants. Includes electricity generation AND production of useful thermal output,not electricity-only emissions. Source unit is thousand metric tons,not eGRID source tons,pounds,CO2equivalent or emission intensity. Source CO2,SO2 and NOx are distinct pollutants,not summed as one climate measure. Displayed zero values may represent small values rounded to zero;no absence or zero-emissions certification. Retain displayed HTML precision;source says Excel cells provide additional precision,not adopted here. No direct eGRID trend or data center allocation,marginal emissions,ambient concentration,health risk,permit compliance,current2026 activity or Native facility joins.","locator":"Table9.5 years2025 and2024"},"eia_emissions_basis":{"value":"EIA Table9.5 historical state2025 and2024 emissions estimates from energy consumption at conventional power and combined-heat-and-power plants. Includes electricity generation AND production of useful thermal output,not electricity-only emissions. Source unit is thousand metric tons,not eGRID source tons,pounds,CO2equivalent or emission intensity. Source CO2,SO2 and NOx are distinct pollutants,not summed as one climate measure. Displayed zero values may represent small values rounded to zero;no absence or zero-emissions certification. Retain displayed HTML precision;source says Excel cells provide additional precision,not adopted here. No direct eGRID trend or data center allocation,marginal emissions,ambient concentration,health risk,permit compliance,current2026 activity or Native facility joins.","source_ids":["eia-epa2025-state-emissions"],"scope":"EIA Table9.5 historical state2025 and2024 emissions estimates from energy consumption at conventional power and combined-heat-and-power plants. Includes electricity generation AND production of useful thermal output,not electricity-only emissions. Source unit is thousand metric tons,not eGRID source tons,pounds,CO2equivalent or emission intensity. Source CO2,SO2 and NOx are distinct pollutants,not summed as one climate measure. Displayed zero values may represent small values rounded to zero;no absence or zero-emissions certification. Retain displayed HTML precision;source says Excel cells provide additional precision,not adopted here. No direct eGRID trend or data center allocation,marginal emissions,ambient concentration,health risk,permit compliance,current2026 activity or Native facility joins.","locator":"Table9.5 header and methodological notes"},"eia_emissions_co2_2025":{"value":11833.0,"source_ids":["eia-epa2025-state-emissions"],"scope":"EIA Table9.5 historical state2025 and2024 emissions estimates from energy consumption at conventional power and combined-heat-and-power plants. Includes electricity generation AND production of useful thermal output,not electricity-only emissions. Source unit is thousand metric tons,not eGRID source tons,pounds,CO2equivalent or emission intensity. Source CO2,SO2 and NOx are distinct pollutants,not summed as one climate measure. Displayed zero values may represent small values rounded to zero;no absence or zero-emissions certification. Retain displayed HTML precision;source says Excel cells provide additional precision,not adopted here. No direct eGRID trend or data center allocation,marginal emissions,ambient concentration,health risk,permit compliance,current2026 activity or Native facility joins.","locator":"Table9.5 Montana row;co2;Year 2025","source_token":"11,833","unit":"thousand metric tons","measurement_role":"agency_estimated_generation_and_useful_thermal_emissions"},"eia_emissions_co2_2024":{"value":11839.0,"source_ids":["eia-epa2025-state-emissions"],"scope":"EIA Table9.5 historical state2025 and2024 emissions estimates from energy consumption at conventional power and combined-heat-and-power plants. Includes electricity generation AND production of useful thermal output,not electricity-only emissions. Source unit is thousand metric tons,not eGRID source tons,pounds,CO2equivalent or emission intensity. Source CO2,SO2 and NOx are distinct pollutants,not summed as one climate measure. Displayed zero values may represent small values rounded to zero;no absence or zero-emissions certification. Retain displayed HTML precision;source says Excel cells provide additional precision,not adopted here. No direct eGRID trend or data center allocation,marginal emissions,ambient concentration,health risk,permit compliance,current2026 activity or Native facility joins.","locator":"Table9.5 Montana row;co2;Year 2024","source_token":"11,839","unit":"thousand metric tons","measurement_role":"agency_estimated_generation_and_useful_thermal_emissions"},"eia_emissions_so2_2025":{"value":7.0,"source_ids":["eia-epa2025-state-emissions"],"scope":"EIA Table9.5 historical state2025 and2024 emissions estimates from energy consumption at conventional power and combined-heat-and-power plants. Includes electricity generation AND production of useful thermal output,not electricity-only emissions. Source unit is thousand metric tons,not eGRID source tons,pounds,CO2equivalent or emission intensity. Source CO2,SO2 and NOx are distinct pollutants,not summed as one climate measure. Displayed zero values may represent small values rounded to zero;no absence or zero-emissions certification. Retain displayed HTML precision;source says Excel cells provide additional precision,not adopted here. No direct eGRID trend or data center allocation,marginal emissions,ambient concentration,health risk,permit compliance,current2026 activity or Native facility joins.","locator":"Table9.5 Montana row;so2;Year 2025","source_token":"7","unit":"thousand metric tons","measurement_role":"agency_estimated_generation_and_useful_thermal_emissions"},"eia_emissions_so2_2024":{"value":7.0,"source_ids":["eia-epa2025-state-emissions"],"scope":"EIA Table9.5 historical state2025 and2024 emissions estimates from energy consumption at conventional power and combined-heat-and-power plants. Includes electricity generation AND production of useful thermal output,not electricity-only emissions. Source unit is thousand metric tons,not eGRID source tons,pounds,CO2equivalent or emission intensity. Source CO2,SO2 and NOx are distinct pollutants,not summed as one climate measure. Displayed zero values may represent small values rounded to zero;no absence or zero-emissions certification. Retain displayed HTML precision;source says Excel cells provide additional precision,not adopted here. No direct eGRID trend or data center allocation,marginal emissions,ambient concentration,health risk,permit compliance,current2026 activity or Native facility joins.","locator":"Table9.5 Montana row;so2;Year 2024","source_token":"7","unit":"thousand metric tons","measurement_role":"agency_estimated_generation_and_useful_thermal_emissions"},"eia_emissions_nox_2025":{"value":15.0,"source_ids":["eia-epa2025-state-emissions"],"scope":"EIA Table9.5 historical state2025 and2024 emissions estimates from energy consumption at conventional power and combined-heat-and-power plants. Includes electricity generation AND production of useful thermal output,not electricity-only emissions. Source unit is thousand metric tons,not eGRID source tons,pounds,CO2equivalent or emission intensity. Source CO2,SO2 and NOx are distinct pollutants,not summed as one climate measure. Displayed zero values may represent small values rounded to zero;no absence or zero-emissions certification. Retain displayed HTML precision;source says Excel cells provide additional precision,not adopted here. No direct eGRID trend or data center allocation,marginal emissions,ambient concentration,health risk,permit compliance,current2026 activity or Native facility joins.","locator":"Table9.5 Montana row;nox;Year 2025","source_token":"15","unit":"thousand metric tons","measurement_role":"agency_estimated_generation_and_useful_thermal_emissions"},"eia_emissions_nox_2024":{"value":12.0,"source_ids":["eia-epa2025-state-emissions"],"scope":"EIA Table9.5 historical state2025 and2024 emissions estimates from energy consumption at conventional power and combined-heat-and-power plants. Includes electricity generation AND production of useful thermal output,not electricity-only emissions. Source unit is thousand metric tons,not eGRID source tons,pounds,CO2equivalent or emission intensity. Source CO2,SO2 and NOx are distinct pollutants,not summed as one climate measure. Displayed zero values may represent small values rounded to zero;no absence or zero-emissions certification. Retain displayed HTML precision;source says Excel cells provide additional precision,not adopted here. No direct eGRID trend or data center allocation,marginal emissions,ambient concentration,health risk,permit compliance,current2026 activity or Native facility joins.","locator":"Table9.5 Montana row;nox;Year 2024","source_token":"12","unit":"thousand metric tons","measurement_role":"agency_estimated_generation_and_useful_thermal_emissions"}}}],"sources":{"mt-air-assistance-20261025":{"url":"https://deq.mt.gov/air/assistance","title":"Montana DEQ air permitting and operator assistance","publisher":"Montana Department of Environmental Quality","published_on":null,"date_note":"Original guidance date unknown; source check is not rule effective date.","scope":"Montana DEQ New Facilities, Permitted Sources, MAQP and TitleV FAQ reviewed. Linked current ARM rules and registration programs not fully reviewed. Numeric thresholds and individual applicability not determined.","checked_at":"2026-10-25T12:58:36.447739+00:00","sha256":"765b536c3938c7d741746e5c621201e7b58cf6e96107cb4d4292becf47c3e504","tier":"A","establishes_status":["program"]},"epa-egrid2023-states-rev2":{"url":"https://www.epa.gov/system/files/documents/2025-06/egrid2023_data_rev2.xlsx","title":"EPA eGRID2023 revision2 original workbook ST23 state emissions,generation and total output rates","publisher":"U.S. Environmental Protection Agency","published_on":null,"date_note":"Exact workbook publication day not established;2025-06 path is a storage folder,not an exact publication date.2023 is report year,not retrieval year.","checked_at":"2026-10-27T21:05:24.064631+00:00","sha256":"895cd81dd8662406189ad8adf5a2578dcb362cdb5cff7cca81b10ee6bd2447c6","raw_path":"/Users/shaunwilson/Documents/Data Centers Atlas/build/cache/layers-20261023/epa-egrid2023-data-rev2.bin","tier":"A","scope":"EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence. Download index identifies eGRID2023 revision2;only workbook metadata/shared strings/ST23 entries read,no whole-archive extraction.","establishes_status":["historical"]},"eia-epa2025-state-emissions":{"url":"https://www.eia.gov/electricity/annual/table.php?t=epa_09_05.html","publisher":"U.S. Energy Information Administration","title":"Electric Power Annual Table9.5 state power and CHP emissions2025 and2024","published_on":"2026-10-21","checked_at":"2026-10-28T02:40:42.051795+00:00","sha256":"36e6dbf2164041a56f6985a5fcac8357791d95eb82545bfc542aea095c38d5dd","raw_path":"/Users/shaunwilson/Documents/Data Centers Atlas/build/cache/layers-20261023/eia-epa2025-state-emissions-20261028.html","tier":"A","establishes_status":["historical"],"scope":"EIA Table9.5 historical state2025 and2024 emissions estimates from energy consumption at conventional power and combined-heat-and-power plants. Includes electricity generation AND production of useful thermal output,not electricity-only emissions. Source unit is thousand metric tons,not eGRID source tons,pounds,CO2equivalent or emission intensity. Source CO2,SO2 and NOx are distinct pollutants,not summed as one climate measure. Displayed zero values may represent small values rounded to zero;no absence or zero-emissions certification. Retain displayed HTML precision;source says Excel cells provide additional precision,not adopted here. No direct eGRID trend or data center allocation,marginal emissions,ambient concentration,health risk,permit compliance,current2026 activity or Native facility joins."}},"details":[{"id":"air-mt-permit-framework-20261025","html":"<article><h3>Montana construction and operating permit framework boundaries</h3><p class=\"layer-scope\">Montana DEQ New Facilities, Permitted Sources, MAQP and TitleV FAQ reviewed. Linked current ARM rules and registration programs not fully reviewed. Numeric thresholds and individual applicability not determined.</p><dl class=\"layer-fields\"><dt>Mt permit framework basis</dt><dd>Agency guidance distinguishes Montana Air Quality Permit construction authorization from TitleV operating permit requirements.<span class=\"layer-source\"><a href=\"https://deq.mt.gov/air/assistance\">Montana Department of Environmental Quality</a>. Source: Publication date not stated. Checked: October 25, 2026.</span> <p class=\"layer-scope\">Montana DEQ New Facilities, Permitted Sources, MAQP and TitleV FAQ reviewed. Linked current ARM rules and registration programs not fully reviewed. Numeric thresholds and individual applicability not determined. Locator: New Facilities; MAQP and TitleV FAQ.</p></dd><dt>Status</dt><dd>program<span class=\"layer-source\"><a href=\"https://deq.mt.gov/air/assistance\">Montana Department of Environmental Quality</a>. Source: Publication date not stated. Checked: October 25, 2026.</span> <p class=\"layer-scope\">Montana DEQ New Facilities, Permitted Sources, MAQP and TitleV FAQ reviewed. Linked current ARM rules and registration programs not fully reviewed. Numeric thresholds and individual applicability not determined. Locator: New Facilities; MAQP and TitleV FAQ.</p></dd><dt>Mt construction boundary</dt><dd>Where an MAQP is required, agency says apply for and receive it before construction or modification. General guidance does not establish any individual facility approval or installation.<span class=\"layer-source\"><a href=\"https://deq.mt.gov/air/assistance\">Montana Department of Environmental Quality</a>. Source: Publication date not stated. Checked: October 25, 2026.</span> <p class=\"layer-scope\">Montana DEQ New Facilities, Permitted Sources, MAQP and TitleV FAQ reviewed. Linked current ARM rules and registration programs not fully reviewed. Numeric thresholds and individual applicability not determined. Locator: New Facilities; MAQP and TitleV FAQ.</p></dd><dt>Mt term boundary</dt><dd>Agency says MAQPs do not expire and directs existing facility changes to separate review. TitleV operating permits require renewal every5years. Neither statement establishes perpetual compliance or permission for later changes.<span class=\"layer-source\"><a href=\"https://deq.mt.gov/air/assistance\">Montana Department of Environmental Quality</a>. Source: Publication date not stated. Checked: October 25, 2026.</span> <p class=\"layer-scope\">Montana DEQ New Facilities, Permitted Sources, MAQP and TitleV FAQ reviewed. Linked current ARM rules and registration programs not fully reviewed. Numeric thresholds and individual applicability not determined. Locator: New Facilities; MAQP and TitleV FAQ.</p></dd><dt>Mt registration boundary</dt><dd>Registration programs apply to specified industry categories. Oil and gas registration or construction timing is not generalized to data centers or emergency generators.<span class=\"layer-source\"><a href=\"https://deq.mt.gov/air/assistance\">Montana Department of Environmental Quality</a>. Source: Publication date not stated. Checked: October 25, 2026.</span> <p class=\"layer-scope\">Montana DEQ New Facilities, Permitted Sources, MAQP and TitleV FAQ reviewed. Linked current ARM rules and registration programs not fully reviewed. Numeric thresholds and individual applicability not determined. Locator: New Facilities; MAQP and TitleV FAQ.</p></dd><dt>Mt pte boundary</dt><dd>Potential emissions determine applicability, not measured actual emissions. Numeric thresholds in the agency summary were not independently checked against current rules and are not adopted here.<span class=\"layer-source\"><a href=\"https://deq.mt.gov/air/assistance\">Montana Department of Environmental Quality</a>. Source: Publication date not stated. Checked: October 25, 2026.</span> <p class=\"layer-scope\">Montana DEQ New Facilities, Permitted Sources, MAQP and TitleV FAQ reviewed. Linked current ARM rules and registration programs not fully reviewed. Numeric thresholds and individual applicability not determined. Locator: New Facilities; MAQP and TitleV FAQ.</p></dd><dt>Issued permit</dt><dd><span class=\"layer-empty\">Not established</span><span class=\"layer-source\"><a href=\"https://deq.mt.gov/air/assistance\">Montana Department of Environmental Quality</a>. Source: Publication date not stated. Checked: October 25, 2026.</span> <p class=\"layer-scope\">Montana DEQ New Facilities, Permitted Sources, MAQP and TitleV FAQ reviewed. Linked current ARM rules and registration programs not fully reviewed. Numeric thresholds and individual applicability not determined. Locator: New Facilities; MAQP and TitleV FAQ.</p></dd></dl></article>"},{"id":"air-egrid-state-2023-mt","html":"<article><h3>Montana historical2023 electricity-generation emissions</h3><p class=\"layer-scope\">EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence.</p><dl class=\"layer-fields\"><dt>Status</dt><dd>historical<span class=\"layer-source\"><a href=\"https://www.epa.gov/system/files/documents/2025-06/egrid2023_data_rev2.xlsx\">U.S. Environmental Protection Agency</a>. Source: Publication date not stated. Checked: October 27, 2026.</span> <p class=\"layer-scope\">EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence. Locator: ST23 Data Year column.</p></dd><dt>Egrid report year</dt><dd>2023<span class=\"layer-source\"><a href=\"https://www.epa.gov/system/files/documents/2025-06/egrid2023_data_rev2.xlsx\">U.S. Environmental Protection Agency</a>. Source: Publication date not stated. Checked: October 27, 2026.</span> <p class=\"layer-scope\">EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence. Locator: ST23 YEAR column.</p></dd><dt>Egrid state fips</dt><dd>30<span class=\"layer-source\"><a href=\"https://www.epa.gov/system/files/documents/2025-06/egrid2023_data_rev2.xlsx\">U.S. Environmental Protection Agency</a>. Source: Publication date not stated. Checked: October 27, 2026.</span> <p class=\"layer-scope\">EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence. Locator: ST23 FIPSST column.</p></dd><dt>Egrid state basis</dt><dd>EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence.<span class=\"layer-source\"><a href=\"https://www.epa.gov/system/files/documents/2025-06/egrid2023_data_rev2.xlsx\">U.S. Environmental Protection Agency</a>. Source: Publication date not stated. Checked: October 27, 2026.</span> <p class=\"layer-scope\">EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence. Locator: ST23 labels,codes,units and review scope.</p></dd><dt>Egrid annual net generation</dt><dd>26895758.01 MWh<span class=\"layer-source\"><a href=\"https://www.epa.gov/system/files/documents/2025-06/egrid2023_data_rev2.xlsx\">U.S. Environmental Protection Agency</a>. Source: Publication date not stated. Checked: October 27, 2026.</span> <p class=\"layer-scope\">EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence. Locator: ST23 MT row 29, STNGENAN (State annual net generation (MWh)).</p></dd><dt>Egrid annual nox emissions</dt><dd>11734.54 tons<span class=\"layer-source\"><a href=\"https://www.epa.gov/system/files/documents/2025-06/egrid2023_data_rev2.xlsx\">U.S. Environmental Protection Agency</a>. Source: Publication date not stated. Checked: October 27, 2026.</span> <p class=\"layer-scope\">EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence. Locator: ST23 MT row 29, STNOXAN (State annual NOx emissions (tons)).</p></dd><dt>Egrid annual so2 emissions</dt><dd>10875.19 tons<span class=\"layer-source\"><a href=\"https://www.epa.gov/system/files/documents/2025-06/egrid2023_data_rev2.xlsx\">U.S. Environmental Protection Agency</a>. Source: Publication date not stated. Checked: October 27, 2026.</span> <p class=\"layer-scope\">EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence. Locator: ST23 MT row 29, STSO2AN (State annual SO2 emissions (tons)).</p></dd><dt>Egrid annual co2 emissions</dt><dd>14203204.30 tons<span class=\"layer-source\"><a href=\"https://www.epa.gov/system/files/documents/2025-06/egrid2023_data_rev2.xlsx\">U.S. Environmental Protection Agency</a>. Source: Publication date not stated. Checked: October 27, 2026.</span> <p class=\"layer-scope\">EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence. Locator: ST23 MT row 29, STCO2AN (State annual CO2 emissions (tons)).</p></dd><dt>Egrid nox total output rate</dt><dd>0.87 lb per MWh<span class=\"layer-source\"><a href=\"https://www.epa.gov/system/files/documents/2025-06/egrid2023_data_rev2.xlsx\">U.S. Environmental Protection Agency</a>. Source: Publication date not stated. Checked: October 27, 2026.</span> <p class=\"layer-scope\">EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence. Locator: ST23 MT row 29, STNOXRTA (State annual NOx total output emission rate (lb/MWh)).</p></dd><dt>Egrid so2 total output rate</dt><dd>0.81 lb per MWh<span class=\"layer-source\"><a href=\"https://www.epa.gov/system/files/documents/2025-06/egrid2023_data_rev2.xlsx\">U.S. Environmental Protection Agency</a>. Source: Publication date not stated. Checked: October 27, 2026.</span> <p class=\"layer-scope\">EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence. Locator: ST23 MT row 29, STSO2RTA (State annual SO2 total output emission rate (lb/MWh)).</p></dd><dt>Egrid co2 total output rate</dt><dd>1056.17 lb per MWh<span class=\"layer-source\"><a href=\"https://www.epa.gov/system/files/documents/2025-06/egrid2023_data_rev2.xlsx\">U.S. Environmental Protection Agency</a>. Source: Publication date not stated. Checked: October 27, 2026.</span> <p class=\"layer-scope\">EPA eGRID2023 revision2 state electricity-generation emissions context,ST23 worksheet. Historical2023,not current2026 conditions or data center facility emissions. Annual NOx,SO2 andCO2 totals in source tons are distinct from source-reported total output rates in lb/MWh;CO2 is not CO2 equivalent. Annual net generation is MWh,not installed capacity or customer use. Rates are not marginal emissions,ambient concentrations,health effects or emissions factors allocated to a data center. No tons-to-tonnes conversion,rate recomputation,facility join or causal data center inference. State generation context does not establish the mix delivered to consumers. Puerto Rico source row is outside this51state/DC review,not absence. Locator: ST23 MT row 29, STCO2RTA (State annual CO2 total output emission rate (lb/MWh)).</p></dd><dt>Egrid annual ch4 emissions lb</dt><dd>3133348.95 lbs<span class=\"layer-source\"><a href=\"https://www.epa.gov/system/files/documents/2025-06/egrid2023_data_rev2.xlsx\">U.S. Environmental Protection Agency</a>. Source: Publication date not stated. Checked: October 27, 2026.</span> <p class=\"layer-scope\">Historical2023 EPA eGRID ST23 source-reported CH4,N2O,CO2 equivalent and ozone-season NOx context. Annual CH4/N2O totals are source lbs;CO2 equivalent total is source tons;total output rates are lb/MWh. CO2 equivalent differs from raw CO2; no global-warming-potential factor assumed or recomputed,no pounds/tons/metric-tonne conversion. Source-defined ozone-season NOx is not full-year NOx or an ambient ozone concentration. Annual and seasonal rates and totals remain separate,not summed across scopes. No marginal,facility,health-risk or attributable data center emissions inference. Locator: ST23 MT row 29, STCH4AN (State annual CH4 emissions (lbs)).</p></dd><dt>Egrid annual co2e emissions</dt><dd>14307487.31 tons<span class=\"layer-source\"><a href=\"https://www.epa.gov/system/files/documents/2025-06/egrid2023_data_rev2.xlsx\">U.S. Environmental Protection Agency</a>. Source: Publication date not stated. Checked: October 27, 2026.</span> <p class=\"layer-scope\">Historical2023 EPA eGRID ST23 source-reported CH4,N2O,CO2 equivalent and ozone-season NOx context. Annual CH4/N2O totals are source lbs;CO2 equivalent total is source tons;total output rates are lb/MWh. CO2 equivalent differs from raw CO2; no global-warming-potential factor assumed or recomputed,no pounds/tons/metric-tonne conversion. Source-defined ozone-season NOx is not full-year NOx or an ambient ozone concentration. Annual and seasonal rates and totals remain separate,not summed across scopes. No marginal,facility,health-risk or attributable data center emissions inference. Locator: ST23 MT row 29, STCO2EQA (State annual CO2 equivalent emissions (tons)).</p></dd><dt>Egrid annual n2o emissions lb</dt><dd>455970.76 lbs<span class=\"layer-source\"><a href=\"https://www.epa.gov/system/files/documents/2025-06/egrid2023_data_rev2.xlsx\">U.S. Environmental Protection Agency</a>. Source: Publication date not stated. Checked: October 27, 2026.</span> <p class=\"layer-scope\">Historical2023 EPA eGRID ST23 source-reported CH4,N2O,CO2 equivalent and ozone-season NOx context. Annual CH4/N2O totals are source lbs;CO2 equivalent total is source tons;total output rates are lb/MWh. CO2 equivalent differs from raw CO2; no global-warming-potential factor assumed or recomputed,no pounds/tons/metric-tonne conversion. Source-defined ozone-season NOx is not full-year NOx or an ambient ozone concentration. Annual and seasonal rates and totals remain separate,not summed across scopes. No marginal,facility,health-risk or attributable data center emissions inference. Locator: ST23 MT row 29, STN2OAN (State annual N2O emissions (lbs)).</p></dd><dt>Egrid ozone season nox total output rate</dt><dd>0.77 lb per MWh<span class=\"layer-source\"><a href=\"https://www.epa.gov/system/files/documents/2025-06/egrid2023_data_rev2.xlsx\">U.S. Environmental Protection Agency</a>. Source: Publication date not stated. Checked: October 27, 2026.</span> <p class=\"layer-scope\">Historical2023 EPA eGRID ST23 source-reported CH4,N2O,CO2 equivalent and ozone-season NOx context. Annual CH4/N2O totals are source lbs;CO2 equivalent total is source tons;total output rates are lb/MWh. CO2 equivalent differs from raw CO2; no global-warming-potential factor assumed or recomputed,no pounds/tons/metric-tonne conversion. Source-defined ozone-season NOx is not full-year NOx or an ambient ozone concentration. Annual and seasonal rates and totals remain separate,not summed across scopes. No marginal,facility,health-risk or attributable data center emissions inference. Locator: ST23 MT row 29, STNOXRTO (State ozone season NOx total output emission rate (lb/MWh)).</p></dd><dt>Egrid extended basis</dt><dd>Historical2023 EPA eGRID ST23 source-reported CH4,N2O,CO2 equivalent and ozone-season NOx context. Annual CH4/N2O totals are source lbs;CO2 equivalent total is source tons;total output rates are lb/MWh. CO2 equivalent differs from raw CO2; no global-warming-potential factor assumed or recomputed,no pounds/tons/metric-tonne conversion. Source-defined ozone-season NOx is not full-year NOx or an ambient ozone concentration. Annual and seasonal rates and totals remain separate,not summed across scopes. No marginal,facility,health-risk or attributable data center emissions inference.<span class=\"layer-source\"><a href=\"https://www.epa.gov/system/files/documents/2025-06/egrid2023_data_rev2.xlsx\">U.S. Environmental Protection Agency</a>. Source: Publication date not stated. Checked: October 27, 2026.</span> <p class=\"layer-scope\">Historical2023 EPA eGRID ST23 source-reported CH4,N2O,CO2 equivalent and ozone-season NOx context. Annual CH4/N2O totals are source lbs;CO2 equivalent total is source tons;total output rates are lb/MWh. CO2 equivalent differs from raw CO2; no global-warming-potential factor assumed or recomputed,no pounds/tons/metric-tonne conversion. Source-defined ozone-season NOx is not full-year NOx or an ambient ozone concentration. Annual and seasonal rates and totals remain separate,not summed across scopes. No marginal,facility,health-risk or attributable data center emissions inference. Locator: ST23 field labels,report year and annual-versus-ozone-season units.</p></dd><dt>Egrid ozone season nox emissions</dt><dd>4196.94 tons<span class=\"layer-source\"><a href=\"https://www.epa.gov/system/files/documents/2025-06/egrid2023_data_rev2.xlsx\">U.S. Environmental Protection Agency</a>. Source: Publication date not stated. Checked: October 27, 2026.</span> <p class=\"layer-scope\">Historical2023 EPA eGRID ST23 source-reported CH4,N2O,CO2 equivalent and ozone-season NOx context. Annual CH4/N2O totals are source lbs;CO2 equivalent total is source tons;total output rates are lb/MWh. CO2 equivalent differs from raw CO2; no global-warming-potential factor assumed or recomputed,no pounds/tons/metric-tonne conversion. Source-defined ozone-season NOx is not full-year NOx or an ambient ozone concentration. Annual and seasonal rates and totals remain separate,not summed across scopes. No marginal,facility,health-risk or attributable data center emissions inference. Locator: ST23 MT row 29, STNOXOZ (State ozone season NOx emissions (tons)).</p></dd><dt>Egrid co2e total output rate</dt><dd>1063.92 lb per MWh<span class=\"layer-source\"><a href=\"https://www.epa.gov/system/files/documents/2025-06/egrid2023_data_rev2.xlsx\">U.S. Environmental Protection Agency</a>. Source: Publication date not stated. Checked: October 27, 2026.</span> <p class=\"layer-scope\">Historical2023 EPA eGRID ST23 source-reported CH4,N2O,CO2 equivalent and ozone-season NOx context. Annual CH4/N2O totals are source lbs;CO2 equivalent total is source tons;total output rates are lb/MWh. CO2 equivalent differs from raw CO2; no global-warming-potential factor assumed or recomputed,no pounds/tons/metric-tonne conversion. Source-defined ozone-season NOx is not full-year NOx or an ambient ozone concentration. Annual and seasonal rates and totals remain separate,not summed across scopes. No marginal,facility,health-risk or attributable data center emissions inference. Locator: ST23 MT row 29, STC2ERTA (State annual CO2 equivalent total output emission rate (lb/MWh)).</p></dd><dt>Egrid ch4 total output rate</dt><dd>0.12 lb per MWh<span class=\"layer-source\"><a href=\"https://www.epa.gov/system/files/documents/2025-06/egrid2023_data_rev2.xlsx\">U.S. Environmental Protection Agency</a>. Source: Publication date not stated. Checked: October 27, 2026.</span> <p class=\"layer-scope\">Historical2023 EPA eGRID ST23 source-reported CH4,N2O,CO2 equivalent and ozone-season NOx context. Annual CH4/N2O totals are source lbs;CO2 equivalent total is source tons;total output rates are lb/MWh. CO2 equivalent differs from raw CO2; no global-warming-potential factor assumed or recomputed,no pounds/tons/metric-tonne conversion. Source-defined ozone-season NOx is not full-year NOx or an ambient ozone concentration. Annual and seasonal rates and totals remain separate,not summed across scopes. No marginal,facility,health-risk or attributable data center emissions inference. Locator: ST23 MT row 29, STCH4RTA (State annual CH4 total output emission rate (lb/MWh)).</p></dd><dt>Egrid n2o total output rate</dt><dd>0.02 lb per MWh<span class=\"layer-source\"><a href=\"https://www.epa.gov/system/files/documents/2025-06/egrid2023_data_rev2.xlsx\">U.S. Environmental Protection Agency</a>. Source: Publication date not stated. Checked: October 27, 2026.</span> <p class=\"layer-scope\">Historical2023 EPA eGRID ST23 source-reported CH4,N2O,CO2 equivalent and ozone-season NOx context. Annual CH4/N2O totals are source lbs;CO2 equivalent total is source tons;total output rates are lb/MWh. CO2 equivalent differs from raw CO2; no global-warming-potential factor assumed or recomputed,no pounds/tons/metric-tonne conversion. Source-defined ozone-season NOx is not full-year NOx or an ambient ozone concentration. Annual and seasonal rates and totals remain separate,not summed across scopes. No marginal,facility,health-risk or attributable data center emissions inference. Locator: ST23 MT row 29, STN2ORTA (State annual N2O total output emission rate (lb/MWh)).</p></dd></dl></article>"},{"id":"air-eia-state-emissions-2025-mt","html":"<article><h3>Montana historical power and useful thermal emissions2025 and2024</h3><p class=\"layer-scope\">EIA Table9.5 historical state2025 and2024 emissions estimates from energy consumption at conventional power and combined-heat-and-power plants. Includes electricity generation AND production of useful thermal output,not electricity-only emissions. Source unit is thousand metric tons,not eGRID source tons,pounds,CO2equivalent or emission intensity. Source CO2,SO2 and NOx are distinct pollutants,not summed as one climate measure. Displayed zero values may represent small values rounded to zero;no absence or zero-emissions certification. Retain displayed HTML precision;source says Excel cells provide additional precision,not adopted here. No direct eGRID trend or data center allocation,marginal emissions,ambient concentration,health risk,permit compliance,current2026 activity or Native facility joins.</p><dl class=\"layer-fields\"><dt>Status</dt><dd>historical<span class=\"layer-source\"><a href=\"https://www.eia.gov/electricity/annual/table.php?t=epa_09_05.html\">U.S. Energy Information Administration</a>. Source: October 21, 2026. Checked: October 28, 2026.</span> <p class=\"layer-scope\">EIA Table9.5 historical state2025 and2024 emissions estimates from energy consumption at conventional power and combined-heat-and-power plants. Includes electricity generation AND production of useful thermal output,not electricity-only emissions. Source unit is thousand metric tons,not eGRID source tons,pounds,CO2equivalent or emission intensity. Source CO2,SO2 and NOx are distinct pollutants,not summed as one climate measure. Displayed zero values may represent small values rounded to zero;no absence or zero-emissions certification. Retain displayed HTML precision;source says Excel cells provide additional precision,not adopted here. No direct eGRID trend or data center allocation,marginal emissions,ambient concentration,health risk,permit compliance,current2026 activity or Native facility joins. Locator: Table9.5 years2025 and2024.</p></dd><dt>Eia emissions basis</dt><dd>EIA Table9.5 historical state2025 and2024 emissions estimates from energy consumption at conventional power and combined-heat-and-power plants. Includes electricity generation AND production of useful thermal output,not electricity-only emissions. Source unit is thousand metric tons,not eGRID source tons,pounds,CO2equivalent or emission intensity. Source CO2,SO2 and NOx are distinct pollutants,not summed as one climate measure. Displayed zero values may represent small values rounded to zero;no absence or zero-emissions certification. Retain displayed HTML precision;source says Excel cells provide additional precision,not adopted here. No direct eGRID trend or data center allocation,marginal emissions,ambient concentration,health risk,permit compliance,current2026 activity or Native facility joins.<span class=\"layer-source\"><a href=\"https://www.eia.gov/electricity/annual/table.php?t=epa_09_05.html\">U.S. Energy Information Administration</a>. Source: October 21, 2026. Checked: October 28, 2026.</span> <p class=\"layer-scope\">EIA Table9.5 historical state2025 and2024 emissions estimates from energy consumption at conventional power and combined-heat-and-power plants. Includes electricity generation AND production of useful thermal output,not electricity-only emissions. Source unit is thousand metric tons,not eGRID source tons,pounds,CO2equivalent or emission intensity. Source CO2,SO2 and NOx are distinct pollutants,not summed as one climate measure. Displayed zero values may represent small values rounded to zero;no absence or zero-emissions certification. Retain displayed HTML precision;source says Excel cells provide additional precision,not adopted here. No direct eGRID trend or data center allocation,marginal emissions,ambient concentration,health risk,permit compliance,current2026 activity or Native facility joins. Locator: Table9.5 header and methodological notes.</p></dd><dt>Eia emissions co2 2025</dt><dd>11833.00 thousand metric tons<span class=\"layer-source\"><a href=\"https://www.eia.gov/electricity/annual/table.php?t=epa_09_05.html\">U.S. Energy Information Administration</a>. Source: October 21, 2026. Checked: October 28, 2026.</span> <p class=\"layer-scope\">EIA Table9.5 historical state2025 and2024 emissions estimates from energy consumption at conventional power and combined-heat-and-power plants. Includes electricity generation AND production of useful thermal output,not electricity-only emissions. Source unit is thousand metric tons,not eGRID source tons,pounds,CO2equivalent or emission intensity. Source CO2,SO2 and NOx are distinct pollutants,not summed as one climate measure. Displayed zero values may represent small values rounded to zero;no absence or zero-emissions certification. Retain displayed HTML precision;source says Excel cells provide additional precision,not adopted here. No direct eGRID trend or data center allocation,marginal emissions,ambient concentration,health risk,permit compliance,current2026 activity or Native facility joins. Locator: Table9.5 Montana row;co2;Year 2025.</p></dd><dt>Eia emissions co2 2024</dt><dd>11839.00 thousand metric tons<span class=\"layer-source\"><a href=\"https://www.eia.gov/electricity/annual/table.php?t=epa_09_05.html\">U.S. Energy Information Administration</a>. Source: October 21, 2026. Checked: October 28, 2026.</span> <p class=\"layer-scope\">EIA Table9.5 historical state2025 and2024 emissions estimates from energy consumption at conventional power and combined-heat-and-power plants. Includes electricity generation AND production of useful thermal output,not electricity-only emissions. Source unit is thousand metric tons,not eGRID source tons,pounds,CO2equivalent or emission intensity. Source CO2,SO2 and NOx are distinct pollutants,not summed as one climate measure. Displayed zero values may represent small values rounded to zero;no absence or zero-emissions certification. Retain displayed HTML precision;source says Excel cells provide additional precision,not adopted here. No direct eGRID trend or data center allocation,marginal emissions,ambient concentration,health risk,permit compliance,current2026 activity or Native facility joins. Locator: Table9.5 Montana row;co2;Year 2024.</p></dd><dt>Eia emissions so2 2025</dt><dd>7.00 thousand metric tons<span class=\"layer-source\"><a href=\"https://www.eia.gov/electricity/annual/table.php?t=epa_09_05.html\">U.S. Energy Information Administration</a>. Source: October 21, 2026. Checked: October 28, 2026.</span> <p class=\"layer-scope\">EIA Table9.5 historical state2025 and2024 emissions estimates from energy consumption at conventional power and combined-heat-and-power plants. Includes electricity generation AND production of useful thermal output,not electricity-only emissions. Source unit is thousand metric tons,not eGRID source tons,pounds,CO2equivalent or emission intensity. Source CO2,SO2 and NOx are distinct pollutants,not summed as one climate measure. Displayed zero values may represent small values rounded to zero;no absence or zero-emissions certification. Retain displayed HTML precision;source says Excel cells provide additional precision,not adopted here. No direct eGRID trend or data center allocation,marginal emissions,ambient concentration,health risk,permit compliance,current2026 activity or Native facility joins. Locator: Table9.5 Montana row;so2;Year 2025.</p></dd><dt>Eia emissions so2 2024</dt><dd>7.00 thousand metric tons<span class=\"layer-source\"><a href=\"https://www.eia.gov/electricity/annual/table.php?t=epa_09_05.html\">U.S. Energy Information Administration</a>. Source: October 21, 2026. Checked: October 28, 2026.</span> <p class=\"layer-scope\">EIA Table9.5 historical state2025 and2024 emissions estimates from energy consumption at conventional power and combined-heat-and-power plants. Includes electricity generation AND production of useful thermal output,not electricity-only emissions. Source unit is thousand metric tons,not eGRID source tons,pounds,CO2equivalent or emission intensity. Source CO2,SO2 and NOx are distinct pollutants,not summed as one climate measure. Displayed zero values may represent small values rounded to zero;no absence or zero-emissions certification. Retain displayed HTML precision;source says Excel cells provide additional precision,not adopted here. No direct eGRID trend or data center allocation,marginal emissions,ambient concentration,health risk,permit compliance,current2026 activity or Native facility joins. Locator: Table9.5 Montana row;so2;Year 2024.</p></dd><dt>Eia emissions nox 2025</dt><dd>15.00 thousand metric tons<span class=\"layer-source\"><a href=\"https://www.eia.gov/electricity/annual/table.php?t=epa_09_05.html\">U.S. Energy Information Administration</a>. Source: October 21, 2026. Checked: October 28, 2026.</span> <p class=\"layer-scope\">EIA Table9.5 historical state2025 and2024 emissions estimates from energy consumption at conventional power and combined-heat-and-power plants. Includes electricity generation AND production of useful thermal output,not electricity-only emissions. Source unit is thousand metric tons,not eGRID source tons,pounds,CO2equivalent or emission intensity. Source CO2,SO2 and NOx are distinct pollutants,not summed as one climate measure. Displayed zero values may represent small values rounded to zero;no absence or zero-emissions certification. Retain displayed HTML precision;source says Excel cells provide additional precision,not adopted here. No direct eGRID trend or data center allocation,marginal emissions,ambient concentration,health risk,permit compliance,current2026 activity or Native facility joins. Locator: Table9.5 Montana row;nox;Year 2025.</p></dd><dt>Eia emissions nox 2024</dt><dd>12.00 thousand metric tons<span class=\"layer-source\"><a href=\"https://www.eia.gov/electricity/annual/table.php?t=epa_09_05.html\">U.S. Energy Information Administration</a>. Source: October 21, 2026. Checked: October 28, 2026.</span> <p class=\"layer-scope\">EIA Table9.5 historical state2025 and2024 emissions estimates from energy consumption at conventional power and combined-heat-and-power plants. Includes electricity generation AND production of useful thermal output,not electricity-only emissions. Source unit is thousand metric tons,not eGRID source tons,pounds,CO2equivalent or emission intensity. Source CO2,SO2 and NOx are distinct pollutants,not summed as one climate measure. Displayed zero values may represent small values rounded to zero;no absence or zero-emissions certification. Retain displayed HTML precision;source says Excel cells provide additional precision,not adopted here. No direct eGRID trend or data center allocation,marginal emissions,ambient concentration,health risk,permit compliance,current2026 activity or Native facility joins. Locator: Table9.5 Montana row;nox;Year 2024.</p></dd></dl></article>"}]}