{"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-ma-certification-guidance-20261025","kind":"permit_context","state_codes":["ma"],"subject":"Massachusetts engine certification timing and route limits","scope":"Agency guidance distinguishes emergency and nonemergency certification clocks and conditional routes.","fields":{"ma_certification_basis":{"value":"Agency compliance certification guidance, not individual engine approval or a complete regulation inventory.","source_ids":["ma-engine-certification-20261025"],"locator":"What to Know and Next steps","scope":"Agency guidance on certification routes and timing, not individual permit, actual installed equipment or complete law."},"status":{"value":"program","source_ids":["ma-engine-certification-20261025"],"locator":"What to Know and Next steps","scope":"Agency guidance on certification routes and timing, not individual permit, actual installed equipment or complete law."},"emergency_clock":{"value":"Agency says certify within60days of installing an emergency generator, fire pump or similar engine rated at least37kilowatts. Exact37included; installation is not established for a named facility.","source_ids":["ma-engine-certification-20261025"],"locator":"What to Know and Next steps","scope":"Agency guidance on certification routes and timing, not individual permit, actual installed equipment or complete law."},"nonemergency_clock":{"value":"Agency says certify at least30days before installing a nonemergency engine rated at least50kilowatts. Exact50included; different clock from emergency units.","source_ids":["ma-engine-certification-20261025"],"locator":"What to Know and Next steps","scope":"Agency guidance on certification routes and timing, not individual permit, actual installed equipment or complete law."},"route_boundary":{"value":"Most emergency units qualify for certification option; many nonemergency units do not and may need comprehensive plan application after agency consultation. Not universal certification eligibility.","source_ids":["ma-engine-certification-20261025"],"locator":"What to Know and Next steps","scope":"Agency guidance on certification routes and timing, not individual permit, actual installed equipment or complete law."},"certification_scope":{"value":"Owner certifies compliance with all applicable environmental requirements; select emergency or nonemergency workbook, instructions and form for installation. Guidance alone does not prove actual compliance.","source_ids":["ma-engine-certification-20261025"],"locator":"What to Know and Next steps","scope":"Agency guidance on certification routes and timing, not individual permit, actual installed equipment or complete law."},"supplier_requirement":{"value":"For each new nonemergency engine or turbine, supplier certification addresses specified ammonia, carbon dioxide, carbon monoxide, nitrogen oxides and particulate emission limits. Numeric limits not reviewed.","source_ids":["ma-engine-certification-20261025"],"locator":"What to Know and Next steps","scope":"Agency guidance on certification routes and timing, not individual permit, actual installed equipment or complete law."},"return_plan":{"value":"Return to Compliance Plan only for violations not corrected before certifying, using matching emergency or nonemergency form. No reviewed individual violation or filed plan.","source_ids":["ma-engine-certification-20261025"],"locator":"What to Know and Next steps","scope":"Agency guidance on certification routes and timing, not individual permit, actual installed equipment or complete law."},"source_review_boundary":{"value":"Selected substantive agency certification guidance reviewed. Linked forms and workbooks not reviewed; downloaded full310CMR7courtesy rule retained as research only, not admitted as current complete law.","source_ids":["ma-engine-certification-20261025"],"locator":"What to Know and Next steps","scope":"Agency guidance on certification routes and timing, not individual permit, actual installed equipment or complete law."},"individual_certification":{"value":null,"source_ids":["ma-engine-certification-20261025"],"locator":"What to Know and Next steps","scope":"Agency guidance on certification routes and timing, not individual permit, actual installed equipment or complete law.","unknown_reason":"No named facility certification, engine inventory or operating record reviewed. Unknown is not zero."},"actual_operation":{"value":null,"source_ids":["ma-engine-certification-20261025"],"locator":"What to Know and Next steps","scope":"Agency guidance on certification routes and timing, not individual permit, actual installed equipment or complete law.","unknown_reason":"No named facility certification, engine inventory or operating record reviewed. Unknown is not zero."},"atlas_record_id":{"value":null,"source_ids":["ma-engine-certification-20261025"],"locator":"What to Know and Next steps","scope":"Agency guidance on certification routes and timing, not individual permit, actual installed equipment or complete law.","unknown_reason":"No named facility certification, engine inventory or operating record reviewed. Unknown is not zero."}}},{"id":"air-egrid-state-2023-ma","subject":"Massachusetts historical2023 electricity-generation emissions","kind":"emissions_context","state_codes":["ma"],"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":"25","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":19663313.081,"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 MA row 22, STNGENAN (State annual net generation (MWh))","unit":"MWh","measurement_role":"reported_egrid_annual_net_generation","source_token":"19663313.081"},"egrid_annual_nox_emissions":{"value":5834.687,"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 MA row 22, STNOXAN (State annual NOx emissions (tons))","unit":"tons","measurement_role":"reported_egrid_annual_nox_emissions","source_token":"5834.6869999999999"},"egrid_annual_so2_emissions":{"value":2736.281,"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 MA row 22, STSO2AN (State annual SO2 emissions (tons))","unit":"tons","measurement_role":"reported_egrid_annual_so2_emissions","source_token":"2736.2809999999999"},"egrid_annual_co2_emissions":{"value":8085460.855,"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 MA row 22, STCO2AN (State annual CO2 emissions (tons))","unit":"tons","measurement_role":"reported_egrid_annual_co2_emissions","source_token":"8085460.8550000004"},"egrid_nox_total_output_rate":{"value":0.593,"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 MA row 22, STNOXRTA (State annual NOx total output emission rate (lb/MWh))","unit":"lb per MWh","measurement_role":"reported_egrid_nox_total_output_rate","source_token":"0.59299999999999997"},"egrid_so2_total_output_rate":{"value":0.278,"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 MA row 22, STSO2RTA (State annual SO2 total output emission rate (lb/MWh))","unit":"lb per MWh","measurement_role":"reported_egrid_so2_total_output_rate","source_token":"0.27800000000000002"},"egrid_co2_total_output_rate":{"value":822.39,"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 MA row 22, STCO2RTA (State annual CO2 total output emission rate (lb/MWh))","unit":"lb per MWh","measurement_role":"reported_egrid_co2_total_output_rate","source_token":"822.39"},"egrid_annual_ch4_emissions_lb":{"value":2444977.846,"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 MA row 22, STCH4AN (State annual CH4 emissions (lbs))","unit":"lbs","measurement_role":"reported_egrid_annual_ch4_emissions","source_token":"2444977.8459999999"},"egrid_annual_co2e_emissions":{"value":8161268.674,"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 MA row 22, STCO2EQA (State annual CO2 equivalent emissions (tons))","unit":"tons","measurement_role":"reported_egrid_annual_co2e_emissions","source_token":"8161268.6739999996"},"egrid_annual_n2o_emissions_lb":{"value":313797.211,"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 MA row 22, STN2OAN (State annual N2O emissions (lbs))","unit":"lbs","measurement_role":"reported_egrid_annual_n2o_emissions","source_token":"313797.21100000001"},"egrid_ozone_season_nox_total_output_rate":{"value":0.564,"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 MA row 22, 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":"0.56399999999999995"},"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":2515.175,"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 MA row 22, STNOXOZ (State ozone season NOx emissions (tons))","unit":"tons","measurement_role":"reported_egrid_ozone_season_nox_emissions","source_token":"2515.1750000000002"},"egrid_co2e_total_output_rate":{"value":830.101,"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 MA row 22, 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":"830.101"},"egrid_ch4_total_output_rate":{"value":0.124,"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 MA row 22, STCH4RTA (State annual CH4 total output emission rate (lb/MWh))","unit":"lb per MWh","measurement_role":"reported_egrid_ch4_total_output_rate","source_token":"0.124"},"egrid_n2o_total_output_rate":{"value":0.016,"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 MA row 22, STN2ORTA (State annual N2O total output emission rate (lb/MWh))","unit":"lb per MWh","measurement_role":"reported_egrid_n2o_total_output_rate","source_token":"1.6E-2"}}},{"id":"air-eia-state-emissions-2025-ma","kind":"emissions_context","subject":"Massachusetts historical power and useful thermal emissions2025 and2024","state_codes":["ma"],"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":9599.0,"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 Massachusetts row;co2;Year 2025","source_token":"9,599","unit":"thousand metric tons","measurement_role":"agency_estimated_generation_and_useful_thermal_emissions"},"eia_emissions_co2_2024":{"value":8895.0,"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 Massachusetts row;co2;Year 2024","source_token":"8,895","unit":"thousand metric tons","measurement_role":"agency_estimated_generation_and_useful_thermal_emissions"},"eia_emissions_so2_2025":{"value":2.0,"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 Massachusetts row;so2;Year 2025","source_token":"2","unit":"thousand metric tons","measurement_role":"agency_estimated_generation_and_useful_thermal_emissions"},"eia_emissions_so2_2024":{"value":2.0,"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 Massachusetts row;so2;Year 2024","source_token":"2","unit":"thousand metric tons","measurement_role":"agency_estimated_generation_and_useful_thermal_emissions"},"eia_emissions_nox_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 Massachusetts row;nox;Year 2025","source_token":"7","unit":"thousand metric tons","measurement_role":"agency_estimated_generation_and_useful_thermal_emissions"},"eia_emissions_nox_2024":{"value":8.0,"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 Massachusetts row;nox;Year 2024","source_token":"8","unit":"thousand metric tons","measurement_role":"agency_estimated_generation_and_useful_thermal_emissions"}}}],"sources":{"ma-engine-certification-20261025":{"url":"https://www.mass.gov/how-to/submit-a-compliance-certification-stationary-engine-or-turbine","title":"MassDEP stationary engine compliance certification guidance","publisher":"Massachusetts Department of Environmental Protection","published_on":null,"date_note":"Current fetched agency guidance has no verified original publication date. Check date is separate.","scope":"Substantive What to Know through submission instructions reviewed. Linked workbooks, forms and complete current regulations not reviewed for this row.","checked_at":"2026-10-25T04:38:57.207991+00:00","sha256":"8a64c94d9a395f184f37a14110db2d2ca212776ad908b72a1630959877710e20","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-ma-certification-guidance-20261025","html":"

Massachusetts engine certification timing and route limits

Agency guidance distinguishes emergency and nonemergency certification clocks and conditional routes.

Ma certification basis
Agency compliance certification guidance, not individual engine approval or a complete regulation inventory.Massachusetts Department of Environmental Protection. Source: Publication date not stated. Checked: October 25, 2026.

Agency guidance on certification routes and timing, not individual permit, actual installed equipment or complete law. Locator: What to Know and Next steps.

Status
programMassachusetts Department of Environmental Protection. Source: Publication date not stated. Checked: October 25, 2026.

Agency guidance on certification routes and timing, not individual permit, actual installed equipment or complete law. Locator: What to Know and Next steps.

Emergency clock
Agency says certify within60days of installing an emergency generator, fire pump or similar engine rated at least37kilowatts. Exact37included; installation is not established for a named facility.Massachusetts Department of Environmental Protection. Source: Publication date not stated. Checked: October 25, 2026.

Agency guidance on certification routes and timing, not individual permit, actual installed equipment or complete law. Locator: What to Know and Next steps.

Nonemergency clock
Agency says certify at least30days before installing a nonemergency engine rated at least50kilowatts. Exact50included; different clock from emergency units.Massachusetts Department of Environmental Protection. Source: Publication date not stated. Checked: October 25, 2026.

Agency guidance on certification routes and timing, not individual permit, actual installed equipment or complete law. Locator: What to Know and Next steps.

Route boundary
Most emergency units qualify for certification option; many nonemergency units do not and may need comprehensive plan application after agency consultation. Not universal certification eligibility.Massachusetts Department of Environmental Protection. Source: Publication date not stated. Checked: October 25, 2026.

Agency guidance on certification routes and timing, not individual permit, actual installed equipment or complete law. Locator: What to Know and Next steps.

Certification scope
Owner certifies compliance with all applicable environmental requirements; select emergency or nonemergency workbook, instructions and form for installation. Guidance alone does not prove actual compliance.Massachusetts Department of Environmental Protection. Source: Publication date not stated. Checked: October 25, 2026.

Agency guidance on certification routes and timing, not individual permit, actual installed equipment or complete law. Locator: What to Know and Next steps.

Supplier requirement
For each new nonemergency engine or turbine, supplier certification addresses specified ammonia, carbon dioxide, carbon monoxide, nitrogen oxides and particulate emission limits. Numeric limits not reviewed.Massachusetts Department of Environmental Protection. Source: Publication date not stated. Checked: October 25, 2026.

Agency guidance on certification routes and timing, not individual permit, actual installed equipment or complete law. Locator: What to Know and Next steps.

Return plan
Return to Compliance Plan only for violations not corrected before certifying, using matching emergency or nonemergency form. No reviewed individual violation or filed plan.Massachusetts Department of Environmental Protection. Source: Publication date not stated. Checked: October 25, 2026.

Agency guidance on certification routes and timing, not individual permit, actual installed equipment or complete law. Locator: What to Know and Next steps.

Source review boundary
Selected substantive agency certification guidance reviewed. Linked forms and workbooks not reviewed; downloaded full310CMR7courtesy rule retained as research only, not admitted as current complete law.Massachusetts Department of Environmental Protection. Source: Publication date not stated. Checked: October 25, 2026.

Agency guidance on certification routes and timing, not individual permit, actual installed equipment or complete law. Locator: What to Know and Next steps.

Individual certification
Not establishedMassachusetts Department of Environmental Protection. Source: Publication date not stated. Checked: October 25, 2026.

Agency guidance on certification routes and timing, not individual permit, actual installed equipment or complete law. Locator: What to Know and Next steps.

Actual operation
Not establishedMassachusetts Department of Environmental Protection. Source: Publication date not stated. Checked: October 25, 2026.

Agency guidance on certification routes and timing, not individual permit, actual installed equipment or complete law. Locator: What to Know and Next steps.

Atlas record id
Not establishedMassachusetts Department of Environmental Protection. Source: Publication date not stated. Checked: October 25, 2026.

Agency guidance on certification routes and timing, not individual permit, actual installed equipment or complete law. Locator: What to Know and Next steps.

"},{"id":"air-egrid-state-2023-ma","html":"

Massachusetts historical2023 electricity-generation emissions

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.

Status
historicalU.S. Environmental Protection Agency. Source: Publication date not stated. Checked: October 27, 2026.

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
2023U.S. Environmental Protection Agency. Source: Publication date not stated. Checked: October 27, 2026.

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
25U.S. Environmental Protection Agency. Source: Publication date not stated. Checked: October 27, 2026.

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
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.U.S. Environmental Protection Agency. Source: Publication date not stated. Checked: October 27, 2026.

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
19663313.08 MWhU.S. Environmental Protection Agency. Source: Publication date not stated. Checked: October 27, 2026.

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 MA row 22, STNGENAN (State annual net generation (MWh)).

Egrid annual nox emissions
5834.69 tonsU.S. Environmental Protection Agency. Source: Publication date not stated. Checked: October 27, 2026.

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 MA row 22, STNOXAN (State annual NOx emissions (tons)).

Egrid annual so2 emissions
2736.28 tonsU.S. Environmental Protection Agency. Source: Publication date not stated. Checked: October 27, 2026.

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 MA row 22, STSO2AN (State annual SO2 emissions (tons)).

Egrid annual co2 emissions
8085460.86 tonsU.S. Environmental Protection Agency. Source: Publication date not stated. Checked: October 27, 2026.

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 MA row 22, STCO2AN (State annual CO2 emissions (tons)).

Egrid nox total output rate
0.59 lb per MWhU.S. Environmental Protection Agency. Source: Publication date not stated. Checked: October 27, 2026.

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 MA row 22, STNOXRTA (State annual NOx total output emission rate (lb/MWh)).

Egrid so2 total output rate
0.28 lb per MWhU.S. Environmental Protection Agency. Source: Publication date not stated. Checked: October 27, 2026.

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 MA row 22, STSO2RTA (State annual SO2 total output emission rate (lb/MWh)).

Egrid co2 total output rate
822.39 lb per MWhU.S. Environmental Protection Agency. Source: Publication date not stated. Checked: October 27, 2026.

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 MA row 22, STCO2RTA (State annual CO2 total output emission rate (lb/MWh)).

Egrid annual ch4 emissions lb
2444977.85 lbsU.S. Environmental Protection Agency. Source: Publication date not stated. Checked: October 27, 2026.

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 MA row 22, STCH4AN (State annual CH4 emissions (lbs)).

Egrid annual co2e emissions
8161268.67 tonsU.S. Environmental Protection Agency. Source: Publication date not stated. Checked: October 27, 2026.

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 MA row 22, STCO2EQA (State annual CO2 equivalent emissions (tons)).

Egrid annual n2o emissions lb
313797.21 lbsU.S. Environmental Protection Agency. Source: Publication date not stated. Checked: October 27, 2026.

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 MA row 22, STN2OAN (State annual N2O emissions (lbs)).

Egrid ozone season nox total output rate
0.56 lb per MWhU.S. Environmental Protection Agency. Source: Publication date not stated. Checked: October 27, 2026.

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 MA row 22, STNOXRTO (State ozone season NOx total output emission rate (lb/MWh)).

Egrid extended basis
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.U.S. Environmental Protection Agency. Source: Publication date not stated. Checked: October 27, 2026.

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
2515.18 tonsU.S. Environmental Protection Agency. Source: Publication date not stated. Checked: October 27, 2026.

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 MA row 22, STNOXOZ (State ozone season NOx emissions (tons)).

Egrid co2e total output rate
830.10 lb per MWhU.S. Environmental Protection Agency. Source: Publication date not stated. Checked: October 27, 2026.

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 MA row 22, STC2ERTA (State annual CO2 equivalent total output emission rate (lb/MWh)).

Egrid ch4 total output rate
0.12 lb per MWhU.S. Environmental Protection Agency. Source: Publication date not stated. Checked: October 27, 2026.

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 MA row 22, STCH4RTA (State annual CH4 total output emission rate (lb/MWh)).

Egrid n2o total output rate
0.02 lb per MWhU.S. Environmental Protection Agency. Source: Publication date not stated. Checked: October 27, 2026.

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 MA row 22, STN2ORTA (State annual N2O total output emission rate (lb/MWh)).

"},{"id":"air-eia-state-emissions-2025-ma","html":"

Massachusetts historical power and useful thermal emissions2025 and2024

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.

Status
historicalU.S. Energy Information Administration. Source: October 21, 2026. Checked: October 28, 2026.

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
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.U.S. Energy Information Administration. Source: October 21, 2026. Checked: October 28, 2026.

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
9599.00 thousand metric tonsU.S. Energy Information Administration. Source: October 21, 2026. Checked: October 28, 2026.

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 Massachusetts row;co2;Year 2025.

Eia emissions co2 2024
8895.00 thousand metric tonsU.S. Energy Information Administration. Source: October 21, 2026. Checked: October 28, 2026.

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 Massachusetts row;co2;Year 2024.

Eia emissions so2 2025
2.00 thousand metric tonsU.S. Energy Information Administration. Source: October 21, 2026. Checked: October 28, 2026.

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 Massachusetts row;so2;Year 2025.

Eia emissions so2 2024
2.00 thousand metric tonsU.S. Energy Information Administration. Source: October 21, 2026. Checked: October 28, 2026.

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 Massachusetts row;so2;Year 2024.

Eia emissions nox 2025
7.00 thousand metric tonsU.S. Energy Information Administration. Source: October 21, 2026. Checked: October 28, 2026.

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 Massachusetts row;nox;Year 2025.

Eia emissions nox 2024
8.00 thousand metric tonsU.S. Energy Information Administration. Source: October 21, 2026. Checked: October 28, 2026.

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 Massachusetts row;nox;Year 2024.

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