{
  "dataset": "plume-ledger",
  "calculation_version": "plume-ledger-analysis-1",
  "built_at": "2026-10-23T03:28:23Z",
  "coverage_label": "LMOP landfill inventory (September 2024) plus 2023 GHGRP Subpart HH reporters missing from that file. Not a census of every U.S. landfill.",
  "aircraft": {
    "title": "Dataset for Science 2024 Publication",
    "publisher": "U.S. EPA Office of Research and Development",
    "doi": "https://doi.org/10.23719/1531980",
    "paper": "https://www.science.org/doi/10.1126/science.adi7735",
    "catalog": "https://catalog.data.gov/dataset/dataset-for-science-2024-publication",
    "file": "science.adi7735_data_s1.xlsx",
    "observation_period": "2016-09-11 to 2022-10-24",
    "rate_unit": "kg/h CH4",
    "annualization": "derived_kg_h_times_8.76",
    "annualization_factor": 8.76
  },
  "ghgrp": {
    "file": "2023 data summary spreadsheets (reporting years 2016-2023)",
    "url": "https://www.epa.gov/ghgreporting/data-sets",
    "download": "https://www.epa.gov/system/files/other-files/2024-10/2023_data_summary_spreadsheets.zip",
    "as_of": "2024-08-16",
    "co2e_gwp": "IPCC AR4",
    "ch4_gwp_used_to_recover_mass": 25.0,
    "comparison_rule": "mean of Subpart HH implied CH4 tonnes in calendar years that contain an overpass"
  },
  "lmop": {
    "vintage": "September 2024",
    "url": "https://www.epa.gov/lmop/landfill-technical-data",
    "download": "https://www.epa.gov/system/files/documents/2024-09/landfilllmopdata.xlsx",
    "file": "landfilllmopdata.xlsx"
  },
  "population": {
    "summary": "Area-weighted ACS 2023 5-year block-group population (B01003) on TIGER/Line 2023 block groups. Buffers of 1, 3, and 5 km. In-state block groups only. Estimates produced for 2324 facilities.",
    "acs": "ACS 2023 5-year, table B01003 total population",
    "geography": "TIGER/Line 2023 block groups",
    "method": "area-weighted intersection of 1/3/5 km buffers, facility state only",
    "vintage": "ACS 2019-2023 5-year estimates, 2023 geography",
    "median_population_3km_inventory": 1634,
    "median_population_3km_surveyed": 2137,
    "facilities_with_population_3km": 2324
  },
  "monte_carlo": {
    "draws": 10000,
    "base_seed": 20241022,
    "distribution": "normal(source mean kg/h, source uncertainty kg/h), truncated at 0, then * 8.76",
    "reported_total": "fixed published value"
  },
  "scenario_factors": {
    "gwp20_biogenic_ch4": 79.7,
    "gwp100_biogenic_ch4": 27.0,
    "gwp_source": "IPCC AR6 WGI Table 7.15 (2021), non-fossil methane",
    "vehicle_t_co2e_per_year": 4.29,
    "vehicle_source": "https://www.epa.gov/energy/greenhouse-gas-equivalencies-calculator-calculations-and-references"
  },
  "counts": {
    "lmop_rows": 2641,
    "ghgrp_hh_2023": 1125,
    "facilities": 2646,
    "facilities_with_coordinates": 2328,
    "aircraft_ghgrp_ids": 114,
    "surveyed": 113,
    "surveyed_exact_lmop_joins": 113,
    "comparison_eligible": 95,
    "states_surveyed": [
      "AL",
      "AZ",
      "CA",
      "CO",
      "FL",
      "GA",
      "KY",
      "LA",
      "MI",
      "NC",
      "NV",
      "NY",
      "OH",
      "OK",
      "PA",
      "TX",
      "UT",
      "VA",
      "WV"
    ],
    "state_count_surveyed": 19,
    "flags_surveyed": {
      "strong_gap": 16,
      "moderate_gap": 22,
      "no_gap_detected": 57,
      "insufficient_data": 18
    }
  },
  "our_statistics": {
    "ratio_of_sums": 1.641,
    "median_facility_ratio": 0.953,
    "mean_facility_ratio": 2.652,
    "sum_observed_t": 799421.0,
    "sum_reported_t": 487143.8,
    "spearman": {
      "rho": 0.3618,
      "p_value": 0.000315,
      "n": 95,
      "note": "Spearman rank correlation of derived annual point-source equivalents and reported CH4. Not a causal estimate."
    }
  },
  "published_study_reference": {
    "citation": "Cusworth et al., Science, 2024. https://doi.org/10.1126/science.adi7735",
    "facilities_surveyed": "200+",
    "states": 18,
    "share_with_point_source_plumes": 0.52,
    "persistent_share_of_measured_emissions": 0.87,
    "measured_vs_reported": "about 1.4\u00d7",
    "note": "These are the paper's published figures. They are not results of this pipeline and are not forced to match."
  },
  "example_facility_id": "lmop-7",
  "warnings": [
    "Aircraft GHGRP IDs with no inventory record: 7837",
    "No ACS 2023 block-group population rows for GU. Those facilities stay blank rather than zero.",
    "No ACS 2023 block-group population rows for VI. Those facilities stay blank rather than zero."
  ],
  "checksums": {
    "cusworth_sha256": "a0e78827cb0fe3f045b767dbaad93c0e66883c480ca17bb3bc498c6b324ff30b",
    "lmop_sha256": "2fc1d72ca9c022fb3ce9225f3b4ae5466b0b9c28b7d7efe7a10d2ac1415a0aa6",
    "ghgrp_zip_sha256": "895349c8008b7962dba68659c8187cec6b340d68be84ccb3f0e7fb6037bf8345"
  }
}