Studies · CA Air Quality · Investigation 05

Which Gas Plants Kill the Most People?

California has 68 in-scope power plants (67 gas-fired + 1 biomass) emitting enough pollution to cause 11.2 attributable deaths per year. But the burden is not spread evenly. The lone biomass plant — DTE Stockton — accounts for one-third of all facility-level mortality. The environmental justice implications are concentrated at a single site.

68
Gas Plants
11.2
Deaths / Year
33%
From One Plant
$129.8M
Health Cost / Year
Facility Ranking

The Top 10 Deadliest Plants

Facility-level health impacts were computed by running each plant’s emissions through InMAP’s source–receptor matrix (ISRM) to estimate PM2.5 concentration increments at every census tract in California, then applying the Di et al. concentration–response function and VSL ($11.6M) to monetize the resulting mortality.

Rank Facility Fuel PM2.5 (short tons) Deaths/yr Health Cost ($M)
1 DTE Stockton Wood 1,067 3.71 $43.0
2 Delta Energy Center Natural Gas 112 0.59 $6.9
3 Haynes Generating Natural Gas 48 0.53 $6.1
4 AES Alamitos Natural Gas 41 0.47 $5.5
5 AES Huntington Beach Natural Gas 50 0.44 $5.1
6 Los Medanos Energy Natural Gas 71 0.42 $4.9
7 Scattergood Generating Natural Gas 49 0.40 $4.6
8 Magnolia Power Project Natural Gas 35 0.36 $4.2
9 Gateway Generating Natural Gas 80 0.34 $3.9
10 Russell City Energy Natural Gas 44 0.30 $3.4

ISRM source–receptor matrix · Di et al. CRF · VSL $11.6M · 2025 emissions (CAMPD, US short tons/yr) · Minimum threshold: 1 short ton NOx

DTE Stockton Deep Dive

One Plant. One-Third of Deaths.

DTE Stockton is not a gas plant. It burns wood — classified as biomass — and emits 1,067 short tons of PM2.5 per year, more than ten times the next highest facility. Its PM2.5 plume reaches 21,163 census tracts across a 108 km footprint, with a peak concentration increment of 5.4 µg/m³.

Deaths / Year
3.71
33% of all facility-level mortality from a single plant
Health Cost
$43.0M
$56.42 per MWh in health externalities
PM2.5 Emissions
1,067 t
10× the next highest emitter (Delta Energy: 112 t)

The next nine plants combined cause 3.8 deaths per year — roughly the same as DTE Stockton alone. The distribution is not a gradual decline; it is a single outlier dominating the entire fleet.

Environmental Justice

Who Bears the Burden?

Of the 21,163 census tracts affected by DTE Stockton’s plume, 5,067 (24%) are designated disadvantaged communities under CalEnviroScreen. The DAC share of DTE’s impact is 35.6% — these communities receive a disproportionate share of the health burden from a single facility.

DTE Stockton is classified as a “biomass” facility and receives renewable energy credits. Its health externality — $43.0M per year, $56.42 per MWh — is larger than any gas plant in California. The renewable classification does not account for the air quality cost.

Among the top 10 plants, the LA Basin cluster (Haynes, AES Alamitos, AES Huntington Beach, Scattergood, Magnolia) collectively impacts communities with DAC shares of 18–32%. But no single gas plant approaches DTE Stockton’s concentration of harm.

Finding
California's 68 in-scope power plants (67 gas-fired + 1 biomass) cause 11.2 deaths per year. DTE Stockton — the lone biomass plant, burning wood — accounts for 33% of all facility-level mortality and 33% of health costs. The environmental justice burden is concentrated at a single site in a disadvantaged community.

InMAP ISRM source–receptor matrix · Di et al. 2017 CRF · VSL $11.6M (EPA 2024) · 2025 CEMS emissions (CAMPD, US short tons/yr) · CalEnviroScreen 4.0 DAC designations · 68 facilities with ≥1 short ton NOx

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