Cook, IL
A PlainEnviro-computed score from reported facility/violation counts, not an official EPA rating, health forecast, or population-adjusted rate. See methodology. This is a different measure than the EJ Screening score for this county, which ranks it by percentile against every other tracked county rather than against fixed national thresholds.
Environmental data for Cook in Illinois · Population: 5,185,812
Cook, IL is tracked across three EPA datasets covering 50 Toxics Release Inventory (TRI) facilities, 203 Safe Drinking Water Act systems, and 0 Superfund National Priorities List sites. Together these generate an environmental burden score of 74/100 (High Risk), calibrated against national distributions for facility density, chemical release volume, Superfund concentration, and water-system health violations.
Industrial disclosures inside the county total 64.6M lbs of reported toxic releases under EPCRA Section 313, while 74 water systems carry an active health-based violation in the SDWIS record. EPA Air Quality System monitors logged a median AQI of 54 and a peak AQI of 166 in 2024, with 36% of observed days rated "Good" (0–50).
All figures below draw directly from federal EPA records, TRI self-reported emissions, SDWIS compliance history, NPL Hazard Ranking System scores, and AQS daily AQI summaries, and are not adjusted, weighted, or forecast. A past violation or elevated score does not itself indicate current unsafe conditions; it documents the regulatory and disclosure history publicly filed with the U.S. Environmental Protection Agency through the most recent reporting cycle.
Air Quality History (2020–2024)
EPA Air Quality Index (AQI) data showing how many days per year fall into each air quality category.
| Year | Good | Moderate | Unhealthy (SG) | Max AQI |
|---|---|---|---|---|
| 2024 | 131 (36%) | 224 | 10 | 166 |
| 2023 | 104 (28%) | 227 | 27 | 223 |
| 2022 | 117 (32%) | 240 | 7 | 151 |
| 2021 | 87 (24%) | 257 | 20 | 156 |
| 2020 | 86 (23%) | 260 | 16 | 164 |
Source: EPA Air Quality System (AQS) Annual AQI by County EPA Air Quality System (AQS) Annual AQI by County AQI categories: Good (0-50), Moderate (51-100), Unhealthy for Sensitive Groups (101-150), Unhealthy (151-200), Very Unhealthy (201-300), Hazardous (301+)
For real-time air quality readings and pollutant breakdowns in Illinois, see the EPA's AirNow.gov.
Water Systems (203)
| System | Population | Violations |
|---|---|---|
| CHICAGO | 2,746,388 | 1 |
| ELGIN | 114,797 | 0 |
| CICERO | 83,000 | 2 |
| SCHAUMBURG | 75,750 | 0 |
| EVANSTON | 74,486 | 1 |
| ARLINGTON HEIGHTS | 73,320 | 0 |
| PALATINE | 70,875 | 2 |
| SKOKIE | 66,422 | 0 |
| DES PLAINES | 60,675 | 0 |
| ORLAND PARK | 58,862 | 0 |
| OAK LAWN | 58,362 | 2 |
| BERWYN | 57,250 | 3 |
| TINLEY PARK | 56,703 | 0 |
| OAK PARK | 54,583 | 2 |
| HOFFMAN ESTATES | 50,179 | 0 |
| GLENVIEW | 47,856 | 2 |
| MOUNT PROSPECT | 41,000 | 0 |
| PARK RIDGE | 39,800 | 1 |
| WHEELING | 39,725 | 2 |
| STREAMWOOD | 39,577 | 0 |
| CALUMET CITY | 37,000 | 2 |
| ELK GROVE VILLAGE | 34,700 | 0 |
| NORTHBROOK | 34,407 | 1 |
| SOUTH STICKNY SD | 30,000 | 1 |
| NILES | 29,350 | 0 |
| LANSING | 29,076 | 0 |
| OAK FOREST | 27,478 | 0 |
| WILMETTE | 27,087 | 0 |
| CHICAGO HEIGHTS | 26,184 | 0 |
| MORTON GROVE | 25,297 | 2 |
| ELMWOOD PARK | 25,000 | 1 |
| HARVEY | 25,000 | 0 |
| MELROSE PARK | 24,206 | 1 |
| MAYWOOD | 24,090 | 1 |
| ROLLING MEADOWS | 23,329 | 0 |
| SOUTH HOLLAND | 22,000 | 8 |
| PARK FOREST | 21,975 | 1 |
| BLUE ISLAND | 21,494 | 1 |
| DOLTON | 20,510 | 0 |
| EVERGREEN PARK | 19,943 | 0 |
| HOMEWOOD | 19,463 | 2 |
| BELLWOOD | 19,156 | 3 |
| ALSIP | 19,063 | 0 |
| BROOKFIELD | 18,776 | 0 |
| PALOS HILLS | 18,530 | 0 |
| FRANKLIN PARK | 18,467 | 0 |
| JUSTICE-WILLOW SPRINGS WATER COMMISSION | 18,457 | 0 |
| MATTESON | 18,293 | 0 |
| LEMONT | 17,500 | 10 |
| COUNTRY CLUB HILLS | 16,500 | 0 |
| BRIDGEVIEW | 16,467 | 0 |
| WESTCHESTER | 16,241 | 2 |
| LA GRANGE | 16,200 | 0 |
| PALOS HEIGHTS | 15,500 | 0 |
| NORRIDGE | 15,251 | 0 |
| MIDLOTHIAN | 14,819 | 1 |
| HICKORY HILLS | 14,505 | 0 |
| FOREST PARK | 14,340 | 0 |
| CHICAGO RIDGE | 14,130 | 0 |
| LINCOLNWOOD | 13,463 | 1 |
| WESTERN SPRINGS | 13,274 | 0 |
| HAZEL CREST | 13,098 | 1 |
| LA GRANGE PARK | 13,011 | 1 |
| NORTHLAKE | 12,840 | 0 |
| RICHTON PARK | 12,504 | 2 |
| MARKHAM | 12,500 | 0 |
| RIVER FOREST | 11,717 | 1 |
| SCHILLER PARK | 11,709 | 3 |
| WORTH | 10,970 | 1 |
| SUMMIT | 10,875 | 0 |
| CRESTWOOD | 10,826 | 0 |
| BARRINGTON | 10,327 | 1 |
| LYONS | 10,304 | 4 |
| RIVER GROVE | 10,282 | 1 |
| RIVERDALE | 10,266 | 3 |
| LEYDEN TWSP WATER DISTRICT | 10,000 | 0 |
| SAUK | 9,921 | 0 |
| FLOSSMOOR | 9,371 | 0 |
| RIVERSIDE | 9,298 | 4 |
| LYNWOOD | 9,149 | 0 |
| HARWOOD HEIGHTS | 9,065 | 1 |
| GLENWOOD | 8,956 | 0 |
| GLENCOE | 8,849 | 0 |
| CALUMET PARK | 8,442 | 1 |
| HILLSIDE | 8,200 | 0 |
| BROADVIEW | 7,847 | 3 |
| NORTH RIVERSIDE | 7,071 | 4 |
| STICKNEY | 6,902 | 1 |
| LA GRANGE HIGHLANDS SANITARY DISTRICT | 6,600 | 0 |
| COUNTRYSIDE | 6,420 | 0 |
| NORTHFIELD | 5,470 | 1 |
| ROBBINS | 5,415 | 0 |
| POSEN | 5,331 | 2 |
| BERKELEY | 5,214 | 1 |
| OLYMPIA FIELDS | 4,922 | 0 |
| PALOS PARK | 4,873 | 0 |
| HOMETOWN | 4,240 | 0 |
| BURNHAM | 3,989 | 1 |
| ROSEMONT | 3,952 | 0 |
| SOUTH CHICAGO HEIGHTS | 3,924 | 1 |
| INDIAN HEAD PARK | 3,240 | 0 |
| OASIS MHP | 3,000 | 0 |
| DIXMOOR | 2,973 | 3 |
| SOUTH PALOS TWSP SANITARY DIST | 2,800 | 1 |
| KENILWORTH | 2,514 | 0 |
| CENTRAL STICKNEY SD | 2,400 | 1 |
| PARADISE VILLAGE | 2,396 | 0 |
| THORNTON | 2,333 | 0 |
| LAKE BARRINGTON SHORES SUBDIVSION | 2,300 | 3 |
| PROSPECT HEIGHTS | 2,280 | 1 |
| PHOENIX | 1,994 | 4 |
| MERRIONETTE PARK | 1,969 | 0 |
| FORD HEIGHTS | 1,813 | 4 |
| EAST HAZEL CREST | 1,500 | 2 |
| HODGKINS | 1,472 | 0 |
| GARDEN HOME SD | 1,472 | 0 |
| SUNSET MHP | 1,400 | 0 |
| ROCK SPRINGS MHP | 1,338 | 0 |
| CASA VERDE MANUFACTURED HOME COMMUNITY | 1,250 | 0 |
| BLACKHAWK ESTATES LLC | 1,238 | 3 |
| FEATHEROCK MHP | 1,044 | 0 |
| OAKBROOK ESTATES MHP | 1,012 | 0 |
| HARBOR POINT ESTATES MHP | 950 | 0 |
| SHADY OAKS MHP | 912 | 0 |
| SPRING LAKES MHP | 904 | 0 |
| WILLOWAY TERRACE MHP | 900 | 0 |
| GLENBROOK SD | 809 | 1 |
| FOREST VIEW | 800 | 0 |
| WHISPERING PINES MHP | 760 | 1 |
| SUNNY ACRES MHP | 750 | 0 |
| CAMBRIDGE COURTS MHP | 658 | 0 |
| BEDFORD PARK | 602 | 0 |
| PARADISE POINT SUBDIVISION | 528 | 0 |
| FRANCISCAN SISTERS OF CHICAGO | 505 | 0 |
| Oronoco Estates MHC | 505 | 0 |
| SHORELINE TRC MHP | 504 | 0 |
| LAKE BARRINGTON | 500 | 0 |
| GOLF | 497 | 0 |
| GRAND ISLAND RESORT MHP (2 WPS) | 480 | 0 |
| RIDGECREST RESORT COMMUNITY | 476 | 0 |
| SUNSHINE WATER SERVICES | 476 | 0 |
| Five Star Mobile Home Park | 458 | 0 |
| LINCOLNWOOD MHP | 450 | 2 |
| LA GRANGE ESTATES MHP | 440 | 0 |
| DES PLAINES MHP | 405 | 16 |
| NHC UTILITIES | 401 | 0 |
| HARVEST VIEW MHC | 400 | 0 |
| ROYAL MELBOURNE HOMEOWNERS ASN | 382 | 0 |
| LINWAY ESTATES MHP | 380 | 0 |
| SUNRISE MHP | 375 | 0 |
| WHISPERING LAKES WATER SYSTEM, INC. | 375 | 0 |
| RIVERVIEW ESTATES | 375 | 0 |
| FOXWOOD FARMS | 332 | 0 |
| GLEN EDEN ESTATES HOMEOWNERS ASSOCIATION | 312 | 5 |
| PLEASANT RIDGE MHP | 284 | 1 |
| MC COOK | 280 | 0 |
| GREEN ACRES NJ MHC LLC | 260 | 0 |
| BROOKSIDE MEADOWS MHP | 250 | 0 |
| STONETOWN EDGEWOOD TERRACE, LLC | 248 | 5 |
| MODENA COUNTRY CLUB | 245 | 0 |
| LINDENTREE TOWNHOMES | 232 | 0 |
| WOODLAND ACRES MHC | 230 | 0 |
| BRIARCREST SBDV HOMEOWNERS ASSOCIATION | 207 | 0 |
| LAKE HICKORY RV RESORT | 200 | 0 |
| ROLLING GREEN ESTATES MHP | 191 | 0 |
| COUNTRY MANOR | 190 | 0 |
| ROYAL OAKS MHP | 170 | 1 |
| LAKE BLUFF ESTATES MHP | 165 | 0 |
| POYNETTE MOBILE ESTATES | 150 | 6 |
| PRAIRIE RIDGE ASSOCIATION | 148 | 1 |
| WOOD DALE ESTATES | 145 | 1 |
| SUGARLOAF MOBILE HOME PARK | 142 | 0 |
| HIGHLAND OAKS MHC | 132 | 0 |
| HARBOR LITES-PISTAKEE FSHG CL | 132 | 0 |
| MAPLE KNOLL | 125 | 1 |
| WHISPERING PINES ESTATES | 125 | 0 |
| TRIANGLE MANUFACTURED HOME COMMUNITY | 124 | 0 |
| THREE MILE LAKE TRAILER PARK | 112 | 0 |
| GOLDEN POND ESTATES | 102 | 0 |
| GROVE SHORES MOBILE HOME COMMUNITY | 100 | 1 |
| SUNRISE SENIOR LIVING | 100 | 0 |
| FALL CREEK MHP | 100 | 3 |
| SANDWICH ESTATES MHP | 90 | 0 |
| SHERWOOD SHORES CONDOMINIUMS | 90 | 4 |
| LAKECREST SHORES LLC | 88 | 0 |
| HAVILAND M.H.P. #1 - ANDREA & DEBRA CT | 78 | 9 |
| APPLEWOOD | 75 | 0 |
| CAMP DEEP LAKE LLC | 75 | 0 |
| EDWARD HINES JR V A HOSPITAL | 60 | 0 |
| VIKING RIVER MOBILE HOME PARK | 55 | 1 |
| HAVILAND M.H.P. #2 - JENNIFER CT | 53 | 0 |
| SHADY BROOK MOBILE HOME PARK | 50 | 0 |
| WOODLAND ESTATES MHC 1 | 50 | 1 |
| WOODLAND ESTATES MHC 2 | 50 | 0 |
| SAGE MEADOW OF LAKE GENEVA | 33 | 0 |
| MID-MARK WATER COMMISSION | 25 | 0 |
| BUSY BEE MHP #1 | 25 | 0 |
| BROOKFIELD-NORTH RIVERSIDE WATER COMM. | 1 | 0 |
| NORTHWEST WATER COMMISSION | 1 | 0 |
| NORTHWEST SUBURBAN MUNICIPAL JAWA | 1 | 0 |
| HILLSIDE BERKELEY WATER COMMISSION | 1 | 0 |
| BROADVIEW-WESTCHESTER JOINT WATER AGENCY | 1 | 0 |
| MORTON GROVE - NILES WATER COMMISSION | 0 | 0 |
TRI Facilities (50)
Cities in Cook (55)
Frequently Asked Questions
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What does this county environmental profile show?
This county environmental profile rolls up EPA Toxics Release Inventory facility reports, Safe Drinking Water Information System public-water-system filings, and Superfund National Priorities List sites for the county boundary defined by the U.S. Census Bureau. Facility counts reflect facilities with a reporting address inside the county, not where downstream environmental effects may be observed. Population figures are from the most recent Census ACS 5-year estimate. The county detail page is updated whenever the upstream EPA programs publish revised data; see the methodology page for the documented ingest cadence and the editorial choices governing how aggregations are computed.
Read our methodology - how this data is sourced, computed, and verified.