Middlesex, MA
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 Middlesex, MA (population 1,622,896).
According to EPA TRI, SDWIS, and Superfund NPL extracts, Middlesex, MA has an environmental burden score of 35/100 (grade B), ranking #428 of 500 counties in this sample. Underlying disclosure counts: 85 TRI facilities releasing 6.4M lbs, 196 health-based SDWIS violation rows, and 15 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 Middlesex, MA: 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 35/100 (grade B), ranking #428 of 500 counties analyzed in the current dataset.
Underlying values: 85 TRI-reporting facilities releasing 6.4M lbs of disclosed toxics; 196 health-based SDWIS violations across the county's water systems; 15 Superfund NPL sites; and 40 facilities reporting carcinogenic chemicals. Of the 15 Superfund sites in this county, 13 are actively listed on the NPL.
Percentile scores compare this county against a national sample of up to 500 counties ranked by the same four indicators. 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 |
|---|---|---|---|---|
| Methanol | 1.3M lbs | No | No | 10 |
| N-Methyl-2-pyrrolidone | 957.4K lbs | No | No | 10 |
| Nitrate compounds (water dissociable; reportable only when in aqueous solution) | 942.0K lbs | No | No | 10 |
| Toluene | 771.3K lbs | No | No | 9 |
| Zinc compounds | 552.2K lbs | No | No | 9 |
| Chloroform | 547.8K lbs | Yes | No | 1 |
| N,N-Dimethylformamide | 164.3K lbs | Yes | No | 5 |
| n-Hexane | 160.6K lbs | No | No | 4 |
| Antimony And Antimony Compounds | 137.0K lbs | No | No | 3 |
| Xylene (mixed isomers) | 105.5K lbs | No | No | 7 |
Which facilities pollute this county the most?
Superfund Sites
What is the environmental burden score for Middlesex, MA?
Middlesex has an environmental burden score of 35/100 (grade: B), ranking #428 out of 500 counties analyzed. This score is based on toxic releases, water quality, Superfund contamination, and carcinogen exposure.
How many TRI facilities are in Middlesex?
Middlesex has 85 TRI (Toxic Release Inventory) facilities reporting to the EPA, with total releases of 6.4M 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 Middlesex's screening report
Use this county's score as a starting point, then drill into the specific concern that matters to you.
- Middlesex has 85 TRI facilities reporting to the EPA -- see which one releases the most. Thermo Fisher Scientific
- Ranked #428 of 500 counties analyzed -- see how Massachusetts as a whole compares nationally. Massachusetts 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.