Total TRI releases
Total TRI releases at Norco have more than doubled since 2010 (through 2024).
City · TRI 2024
Norco, Louisiana Pollution
8 TRI facilities inside the city limits and 0 public water systems serving residents. In-city TRI releases more than tripled year over year (+334%). Toxic releases concentrations have more than doubled since 2010.
FIPS 2255525 · population 2,848 · St. Charles Parish
Anomaly engine
Notable Signals
Pollutant pathways
Norco Pollutant Multi-Year Trends
Ozone 8-hour 4th-highest daily max (NAAQS 0.070 ppm (8-hour))Health riskGround-level ozone (smog) forms when vehicle and industrial emissions react in sunlight. Inflames the airways, triggers asthma attacks, and worsens heart and lung disease.
Ozone 8-hour 4th-highest daily max (NAAQS 0.070 ppm (8-hour)) concentrations have fallen 29% since 2010.
Lifetime cancer risk all pollutants (100 in a million (EPA elevated threshold))Health riskEPA-modeled added cancer cases per million residents from a lifetime of breathing local air toxics. EPA flags 100-in-a-million as elevated.
Single-vintage exposure modeling — EPA cadence is multi-year, so no trend line yet.
Formaldehyde ambient mean (0.077 µg/m³ (1-in-a-million URE))Health riskAn air toxic emitted by refineries, wood products, and combustion. EPA classifies it as a known human carcinogen — long-term inhalation raises cancer risk.
Single-vintage exposure modeling — EPA cadence is multi-year, so no trend line yet.
Benzene ambient mean (0.13 µg/m³ (1-in-a-million URE))Health riskAn air toxic from gasoline, refineries, and tobacco smoke. A known human carcinogen — chronic exposure is linked to leukemia and other blood cancers.
Single-vintage exposure modeling — EPA cadence is multi-year, so no trend line yet.
TRI air releases (5.1 fugitive + 5.2 stack)Health riskToxic chemicals reported by industrial facilities as released into the air — fugitive leaks plus smokestack emissions. Higher pounds means more inhaled exposure for nearby residents.
TRI air releases (5.1 fugitive + 5.2 stack) concentrations have more than doubled since 2010.
TRI water releases (5.3)Health riskToxic chemicals reported by industrial facilities as discharged to surface waters (rivers, lakes, the ocean). Affects fishing, recreation, and downstream drinking-water intakes.
TRI water releases (5.3) concentrations have more than doubled since 2010.
TRI land + off-site releasesHealth riskToxic chemicals released to land on-site or transferred off-site for disposal — landfills, deep-well injection, and similar. Risks groundwater contamination over time.
TRI land + off-site releases concentrations have more than halved since 2010.
Greenhouse gases (GHGRP large emitters, through 2023)Health riskGreenhouse gases reported by large industrial emitters under EPA's GHGRP, in metric tons of CO₂ equivalent. Drives climate warming and the heat-related health effects that follow.
Greenhouse gases (GHGRP large emitters, through 2023) concentrations have fallen 12% since 2010.
Top facilities · TRI 2024
Largest Emitters Inside The City
| Facility | Top chemical | Total releases | YoY |
|---|---|---|---|
| Shell Norco Chemical PlantShell Petroleum INC | PropyleneHealth riskSimple asphyxiant; low direct toxicity at typical exposure levels. (NIOSH) | 5.7M lb | +742% |
| Valero Refining - New Orleans LLCValero Energy CORP | Hydrogen cyanideHealth riskAcutely lethal at high doses by blocking cellular respiration; chronic low-dose exposure damages the thyroid and nervous system. (EPA, ATSDR) | 671k lb | -4% |
| Linde St Charles FacilityLinde INC | Chromium compounds (except for chromite ore mined in the Transvaal Region)Health riskHexavalent chromium (Cr-VI) is an IARC Group 1 carcinogen via inhalation, causing lung cancer; trivalent chromium is far less toxic. (IARC, EPA) | 63k lb | +152% |
| Rain Cii Carbon LLCRain Cii Carbon LLC | Hydrochloric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size)Health riskAerosolized HCl is a corrosive respiratory irritant; chronic exposure damages teeth and respiratory tissue. (NIOSH) | 57k lb | +15% |
| Diamond Green Diesel LLCDiamond Green Diesel | Manganese And Manganese CompoundsHealth riskExcess inhalation can cause manganism, a Parkinson-like neurological disorder. (ATSDR) | 33k lb | -7% |
| Shell Norco Chemical Plant West SiteShell Petroleum INC | BenzeneHealth riskIARC Group 1 carcinogen. Long-term inhalation causes leukemia and bone-marrow disorders. (IARC, EPA) | 19k lb | +7% |
| Shac Catalyst PlantW R Grace & Co | Titanium tetrachloride | 3k lb | -0% |
| Air Products & Chemcials INC Norco SmrAir Products & Chemicals INC | MethanolHealth riskAcutely toxic if ingested or inhaled. Metabolizes to formaldehyde and formic acid, causing blindness and metabolic acidosis. (EPA) | 47 lb | +10% |
Equity context · ACS 2018-2022 · USEPA-clone EJ disparity
Who Lives In Norco
Norco, Louisiana (Census place block groups): 2,848 residents. City disparity score for pm2.5 (fine particulate) sits well below the reference (45). Why we surface this →
12.1%
Low-income
14.7%
People of color
5.4%
Under age 5
14.3%
Over age 64
- PM2.5 (fine particulate)Health riskFine inhalable particles 2.5 micrometers or smaller. They travel deep into the lungs and into the bloodstream — linked to asthma, heart disease, stroke, and premature death.55near the national median
- OzoneHealth riskGround-level ozone (smog) inflames the airways. Even short exposures trigger asthma attacks and worsen chronic lung and heart disease.47near the national median
- Nitrogen dioxide (NO₂)Health riskA tailpipe and combustion gas. Concentrates near busy roads and industrial sites; raises risk of airway inflammation, asthma, and lower respiratory infections in children.39below the national median
- Diesel particulateHealth riskSoot from diesel engines (trucks, trains, ports, construction). EPA classifies it as a likely human carcinogen and a major driver of childhood asthma near freight corridors.77above the national median
- Toxic releases (RSEI)Health riskEPA's Risk-Screening Environmental Indicators score — weights TRI chemical releases by toxicity, where they go, and how many people are nearby. Higher means greater modeled cancer and chronic-health risk.100in the highest 5% nationally
- Traffic proximityHealth riskPopulation-weighted distance to high-volume roads. Living close to heavy traffic raises exposure to PM2.5, NO₂, and diesel exhaust — and the cardiovascular and asthma risks that follow.15below the national median
- Lead-paint risk (pre-1960 housing)Health riskShare of housing built before 1960, when lead-based paint was common. Dust from deteriorating paint is the leading cause of childhood lead poisoning, which permanently impairs cognitive development.77above the national median
- Superfund site proximityHealth riskPopulation-weighted distance to NPL Superfund sites — the most contaminated waste sites in the country. Nearby groundwater, soil, and air can carry industrial solvents, metals, and other long-lived contaminants.56near the national median
- RMP-facility proximityHealth riskDistance to facilities holding chemicals at quantities large enough to require an EPA Risk Management Plan (refineries, fertilizer plants, etc.). These pose acute exposure risk during accidental releases.100in the highest 5% nationally
- Hazardous-waste site proximityHealth riskDistance to RCRA hazardous-waste handlers (treatment, storage, disposal facilities). Indicates potential exposure to industrial chemicals in air, soil, and groundwater.81in the highest 20% nationally
- Underground storage tanksHealth riskDensity of underground tanks (gasoline, heating oil, industrial fluids). Leaking tanks are a leading source of benzene and other volatile organic compounds in groundwater drinking-water supplies.59near the national median
- NPDES wastewater proximityHealth riskDistance to permitted industrial wastewater dischargers. Closer proximity raises exposure to pollutants released into surface waters used for fishing, recreation, and downstream drinking-water intakes.40near the national median
- Drinking-water non-complianceHealth riskEPA score for public water systems with health-based Safe Drinking Water Act violations. Higher means more residents on systems that recently exceeded safe limits for contaminants like lead, arsenic, or nitrate.76above the national median
| Indicator | Disparity score | Reading |
|---|---|---|
| PM2.5 (fine particulate) | 45 | well below the reference |
| Ozone | 10 | well below the reference |
| Nitrogen dioxide (NO₂) | 32 | well below the reference |
| Diesel particulate | 61 | below the reference |
| Toxic releases (RSEI) | 79 | below the reference |
| Traffic proximity | 14 | well below the reference |
| Lead-paint risk (pre-1960 housing) | 58 | below the reference |
| Superfund site proximity | 0 | well below the reference |
| RMP-facility proximity | 79 | below the reference |
| Hazardous-waste site proximity | 64 | below the reference |
| Underground storage tanks | 44 | well below the reference |
| NPDES wastewater proximity | 32 | well below the reference |
| Drinking-water non-compliance | 0 | well below the reference |
Source: Census ACS 2018-2022 (5-year) + USEPA-clone EJ blockgroup stats (raw indicators + EJ disparity mirror).
Health context
Co-Located Health Indicators
Modeled adult-prevalence estimates published by CDC PLACES, paired with this city's pollution and demographic context. Comparisons are ecological, not causal — pollution and disease prevalence covary at the area level, but the data does not attribute any individual's diagnosis to local exposure. How this section works →
Adult asthma (current)
10.1%
CDC PLACES · 2025 release · BRFSS 2022-2023
COPD prevalence
8.1%
CDC PLACES · 2025 release · BRFSS 2022-2023
Coronary heart disease
6.8%
CDC PLACES · 2025 release · BRFSS 2022-2023
Diabetes (diagnosed)
12.1%
CDC PLACES · 2025 release · BRFSS 2022-2023
Frequent mental distress
19.6%
CDC PLACES · 2025 release · BRFSS 2022-2023
PLACES uses BRFSS-modeled small-area estimates, not individual records. Crude prevalence shown above is the local rate as published; comparators are age-adjusted vs the Louisiana mean and the US mean — both population-weighted across counties — so geographies with different age structures stay apples-to-apples. Sources: CDC PLACES · 2025 release · BRFSS 2022-2023.
Sources.
- EPA Toxics Release Inventory · retrieved 2026-05-07.
- EPA Safe Drinking Water Information System · retrieved 2026-05-07.