Maricopa, AZ
According to the U.S. Environmental Protection Agency's 2023 Toxics Release Inventory, Safe Drinking Water Information System, and Superfund National Priorities List, this Environmental Justice Screening Report covers Maricopa, AZ (population 4,491,987).
According to EPA TRI, SDWIS, and Superfund NPL extracts, Maricopa, AZ has an environmental burden score of 36/100 (grade B), ranking #413 of 500 counties in this sample. Underlying disclosure counts: 220 TRI facilities releasing 7.9M lbs, 652 health-based SDWIS violation rows, and 7 Superfund sites. The score is a percentile of federal disclosure footprints, not a diagnosis of current community health harm.
This report synthesizes four indicator layers into a single burden score for Maricopa, AZ: Toxic Release Inventory (TRI) volume, Safe Drinking Water Act health violations, Superfund National Priorities List presence, and carcinogen-releasing facility density. The county's overall score is 36/100 (grade B), ranking #413 of 500 counties analyzed in the current dataset.
Underlying values: 220 TRI-reporting facilities releasing 7.9M lbs of disclosed toxics; 652 health-based SDWIS violations across the county's water systems; 7 Superfund NPL sites; and 118 facilities reporting carcinogenic chemicals. Of the 7 Superfund sites in this county, 5 are actively listed on the NPL.
Transparent derived index from EPA TRI / SDWIS / Superfund extracts: not an official EPA rating. Each of up to 500 counties is percentile-ranked on four rates (toxic lbs per capita 35%, health-based SDWIS rows per water system 25%, Superfund sites per 100k residents 20%, carcinogen-facility share 20%), then weighted. Population-less counties take a neutral 50th percentile on the per-capita indicators. See methodology.
A high burden grade does not by itself establish current health harm; it documents the cumulative regulatory and disclosure footprint drawn from EPA TRI, SDWIS, and Superfund data. Use the indicator breakdown below to see which component drives the score, and drill into the top chemicals and facilities for the underlying Form R filings. This percentile-based score is a different measure than the county profile's fixed-threshold risk score: expect the two numbers to differ.
Top Chemicals Released
| Chemical | Total Released | Carcinogen | PBT | Facilities |
|---|---|---|---|---|
| Aluminum (fume or dust) | 1.6M lbs | No | No | 5 |
| Nitrate compounds (water dissociable; reportable only when in aqueous solution) | 1.2M lbs | No | No | 34 |
| Zinc compounds | 962.9K lbs | No | No | 21 |
| Certain glycol ethers | 787.2K lbs | No | No | 10 |
| Styrene | 701.1K lbs | Yes | No | 9 |
| n-Butyl alcohol | 392.5K lbs | No | No | 3 |
| Hydrogen fluoride | 337.4K lbs | No | No | 11 |
| Ammonia | 212.8K lbs | No | No | 13 |
| Hydrochloric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) | 143.0K lbs | No | No | 10 |
| Nitric acid | 134.1K lbs | No | No | 25 |
Which facilities pollute this county the most?
Superfund Sites
What is the environmental burden score for Maricopa, AZ?
Maricopa has an environmental burden score of 36/100 (grade: B), ranking #413 out of 500 counties analyzed. The score is a transparent derived percentile index of EPA TRI / SDWIS / Superfund disclosure rates: not an official EPA rating or a measured health outcome.
How many TRI facilities are in Maricopa?
Maricopa has 220 TRI (Toxic Release Inventory) facilities reporting to the EPA, with total releases of 7.9M lbs.
Data from U.S. Environmental Protection Agency (EPA). This screening tool is for informational purposes only and is not affiliated with the federal government.
What to do with Maricopa's screening report
Use this county's score as a starting point, then drill into the specific concern that matters to you.
- Maricopa has 220 TRI facilities reporting to the EPA -- see which one releases the most. Imsamet of Arizona
- Ranked #413 of 500 counties analyzed -- see how Arizona as a whole compares nationally. Arizona state profile
- See which counties nationwide carry the highest combined environmental burden. National rankings
This score synthesizes four EPA indicator layers into a single 0-100 index; it is not a health-risk diagnosis or a substitute for local environmental testing.
Read our methodology - how this data is sourced, computed, and verified.
Related
According to the U.S. Environmental Protection Agency, this Environmental Justice Screening Score is computed from the 2023 Toxics Release Inventory, the Safe Drinking Water Information System, and the Superfund National Priorities List, spanning PlainEnviro's database of more than 25,000 EPA-tracked facilities nationwide; see our methodology for the full scoring formula and source citations.