Maricopa, AZ
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 Maricopa in Arizona · Population: 4,491,987
Maricopa, AZ is tracked across three EPA datasets covering 50 Toxics Release Inventory (TRI) facilities, 189 Safe Drinking Water Act systems, and 0 Superfund National Priorities List sites. Together these generate an environmental burden score of 72/100 (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 7.6M lbs of reported toxic releases under EPCRA Section 313, while 87 water systems carry an active health-based violation in the SDWIS record. EPA Air Quality System monitors logged a median AQI of 77 and a peak AQI of 261 in 2024, with 9% 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 | 33 (9%) | 260 | 65 | 261 |
| 2023 | 41 (11%) | 256 | 61 | 183 |
| 2022 | 27 (7%) | 242 | 73 | 264 |
| 2021 | 12 (3%) | 128 | 91 | 297 |
| 2020 | 11 (3%) | 154 | 60 | 282 |
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 Arizona, see the EPA's AirNow.gov.
Water Systems (189)
| System | Population | Violations |
|---|---|---|
| PHOENIX CITY OF | 1,695,000 | 2 |
| GILBERT, TOWN OF | 247,600 | 3 |
| SCOTTSDALE CITY OF | 241,361 | 0 |
| GLENDALE CITY OF | 234,766 | 0 |
| PEORIA CITY OF | 187,676 | 2 |
| ARIZONA WATER CO - PINAL VALLEY | 134,432 | 0 |
| EPCOR - AGUA FRIA | 127,718 | 3 |
| AVONDALE CITY OF | 83,001 | 0 |
| ARIZONA WATER CO - APACHE JUNCTION | 62,055 | 0 |
| LIBERTY WATER LPSCO | 50,770 | 1 |
| GOODYEAR WATER DEPARTMENT | 50,001 | 0 |
| SURPRISE CITY OF - MOUNTAIN VISTA | 40,007 | 0 |
| EL MIRAGE CITY OF | 39,884 | 0 |
| EPCOR - SUN CITY | 38,016 | 0 |
| CITY OF BUCKEYE - VALENCIA TOWN DIVISION | 30,377 | 8 |
| EPCOR - CHAPARRAL CITY | 26,026 | 1 |
| EPCOR - SUN CITY WEST | 25,796 | 0 |
| DESERT OASIS | 23,963 | 0 |
| EPCOR - ANTHEM | 23,826 | 2 |
| Salt River Public Works | 20,951 | 2 |
| PIMA UTILITIES | 20,000 | 4 |
| ARIZONA WATER CO - WHITE TANKS | 18,858 | 0 |
| LAGO DEL ORO WATER COMPANY | 18,132 | 0 |
| CITY OF BUCKEYE SONORA - SUNDANCE | 15,783 | 0 |
| EPCOR - NORTH EAST AGUA FRIA | 14,723 | 0 |
| EPCOR - PARADISE VALLEY/SCOTTSDALE | 14,107 | 0 |
| ARIZONA WATER CO - OVERGAARD | 13,797 | 0 |
| ARIZONA WATER CO - LAKESIDE | 12,191 | 0 |
| ARIZONA WATER CO - SEDONA | 12,104 | 1 |
| ARIZONA WATER CO - ORACLE | 10,585 | 0 |
| FESTIVAL RANCH | 10,313 | 0 |
| CITY OF BUCKEYE TARTESSO WATER SYSTEM | 10,123 | 0 |
| TOLLESON CITY OF | 9,300 | 0 |
| ARIZONA WATER CO - SIERRA VISTA | 9,175 | 2 |
| BEARDSLEY WATER COMPANY 1 | 9,002 | 0 |
| ARIZONA WATER CO - BISBEE | 8,707 | 2 |
| ARIZONA WATER CO - MIAMI CLAYPOOL | 8,656 | 2 |
| USAF LUKE AIR FORCE BASE | 8,440 | 9 |
| ARIZONA WATER CO - PINEWOOD | 8,089 | 0 |
| BUCKEYE CITY OF | 7,008 | 0 |
| SUNRISE WATER COMPANY | 6,490 | 2 |
| WICKENBURG TOWN OF | 6,481 | 0 |
| VALLEY UTILITIES WATER COMPANY GLENDALE | 5,940 | 0 |
| CAVE CREEK WATER | 5,895 | 8 |
| EPCOR- RIO VERDE | 5,330 | 0 |
| EPCOR - TIERRA DEL RIO | 4,868 | 0 |
| EPCOR - LAKE HAVASU | 4,788 | 0 |
| ARIZONA WATER CO - SAN MANUEL | 4,748 | 2 |
| ARIZONA WATER CO - SUPERIOR | 4,393 | 0 |
| ASPC LEWIS COMPLEX WATER SYSTEM | 4,300 | 3 |
| CORDES LAKES WATER COMPANY | 4,257 | 3 |
| DESERT HILLS WATER | 4,220 | 0 |
| MORENCI WATER ELEC CO MAIN | 4,108 | 21 |
| ADOC EYMAN UNIT | 3,969 | 6 |
| CAREFREE WATER COMPANY | 3,894 | 0 |
| ARIZONA WATER CO - PINETOP LAKES | 3,513 | 0 |
| ARIZONA WATER CO - RIMROCK | 3,423 | 2 |
| EPCOR - WILLOW VALLEY/KING STREET | 3,408 | 1 |
| WICKENBURG RANCH ESTATES | 2,877 | 0 |
| PICACHO WATER COMPANY | 2,440 | 0 |
| CLEARWATER UTILITY COMPANY INC | 2,175 | 1 |
| ARIZONA WATER CO - AJO | 2,100 | 0 |
| EPCOR - TUBAC | 2,076 | 0 |
| EAST SLOPE WATER COMPANY | 1,980 | 0 |
| GILA BEND TOWN OF | 1,922 | 0 |
| HORSESHOE BEND WATER SYSTEM | 1,857 | 0 |
| ARIZONA WATER CO - TIERRA GRANDE | 1,796 | 2 |
| AWC - VALLEY VISTA | 1,776 | 0 |
| EPCOR - LAKESIDE | 1,775 | 45 |
| FEDERAL CORRECTION INSTITUTION | 1,500 | 7 |
| MESCAL LAKES WATER SYSTEM | 1,390 | 4 |
| CLEAR SPRINGS UTILITY MAIN | 1,385 | 3 |
| VWC BUCKEYE DIVISION SUN VALLEY | 1,378 | 0 |
| EPCOR - MOOVALYA KEYS | 1,298 | 43 |
| BAY BRIDGE ESTATES LLC | 1,222 | 0 |
| LAKE GRIFFIN ISLES MHP (2 WTPS) | 1,212 | 0 |
| WEST END WATER COMPANY - WITTMAN | 1,200 | 0 |
| ADOT AIRPORT GRAND CANYON | 1,140 | 0 |
| LIVCO WATER COMPANY | 1,120 | 0 |
| BACA FLOAT WATER COMPANY | 1,090 | 0 |
| OAK CREST OF MANVEL | 1,020 | 0 |
| ADOC FLORENCE ASP | 1,001 | 3 |
| ALPINE VILLAGE MHP | 994 | 0 |
| MOUNTAIN GLEN WATER SERVIC LINDEN TRAILS | 975 | 0 |
| AWC - CASA GRANDE WEST WATER COMPANY | 943 | 3 |
| SANDARIO WATER COMPANY | 870 | 3 |
| LONGHORN MEADOWS ADDITION | 855 | 0 |
| WALNUT CREEK WATER COMPANY | 728 | 0 |
| YAVAPAI WATER COMPANY | 728 | 0 |
| THE MEADOWS | 702 | 0 |
| ADAMAN MUTUAL WATER COMPANY | 700 | 4 |
| ADJC ADOBE MOUNTAIN SCHOOL | 680 | 2 |
| GASLIGHT SQUARE MOBILE HOME PARK | 675 | 0 |
| NACO WATER CO MAIN | 658 | 0 |
| EAST SLOPE WATER - WEST | 655 | 2 |
| Salt River Lehi | 652 | 0 |
| ARIZONA WATER CO - STANFIELD | 639 | 2 |
| PATTON PLACE ESTATES | 638 | 0 |
| Mille Lacs Island Resort | 600 | 0 |
| EPCOR - WILLOW VALLEY/LAKE CIMARRON | 596 | 2 |
| PIONEER RV RESORT | 583 | 0 |
| EPCOR - HOLIDAY HARBOR | 559 | 17 |
| EPCOR - MARINA VILLAGE | 528 | 39 |
| SURPRISE, CITY OF BUENA VISTA | 520 | 0 |
| ORANGEWOOD MOBILE HOME PARK | 500 | 2 |
| SEDONA VENTURE WATER COMPANY | 480 | 0 |
| MEADOWLEA ESTATES | 472 | 0 |
| PEAK VIEW RANCH | 470 | 0 |
| ARIZONA TRAINING PROGRAM | 470 | 4 |
| PARADISE MHP | 460 | 2 |
| HILLCREST WATER COMPANY | 454 | 0 |
| ROOSEVELT RANCH RV & MHP | 430 | 0 |
| EPCOR - PARKER DAM | 429 | 37 |
| COUNTRY ESTATES MOBILE HOME PARK | 425 | 1 |
| ARIZONA WATER CO - WINKELMAN | 424 | 0 |
| MOBILE GARDENS DWID | 400 | 2 |
| SAGUARO VIEW MGMT COMPANY | 400 | 0 |
| MICHIGAN TRAILER PARK | 400 | 0 |
| PICACHO PEAK RV RESORT | 400 | 1 |
| WILLOW MANOR MOBILE HOME PARK | 375 | 1 |
| SUNRISE VILLAGE MHP | 353 | 1 |
| WEKIVA FALLS RESORT | 352 | 14 |
| TONTO HILLS DWID | 350 | 0 |
| OCEAN MOBILE HOME PARK | 347 | 1 |
| SHANGRI LA RANCH | 345 | 23 |
| LEISURE LAKE MOBILE ESTATES | 325 | 0 |
| VWC BUCKEYE DIV - SONORAN RIDGE | 322 | 0 |
| DATELAND PUBLIC SERVICE CO | 319 | 4 |
| LAMPLIGHTER RV RESORT | 308 | 0 |
| QUAIL RUN WATER SYSTEM | 300 | 0 |
| HACIENDA DEL SOL MHP | 300 | 1 |
| VENTURA RANCH WATER SYSTEM | 300 | 1 |
| MOUNTAINVIEW MOBILE VILLAGE | 300 | 1 |
| VWC BUCKEYE DIV BULFER PRIMROSE | 280 | 0 |
| SWEETWATER OAKS | 240 | 0 |
| GW SAGUARO DIST WATER CO - RINCON | 232 | 89 |
| OATMAN WATER COMPANY | 230 | 3 |
| EAGLE VIEW MHP | 230 | 0 |
| SUNLAND WATER COMPANY | 227 | 12 |
| RANCHWOOD COMMUNITY | 225 | 0 |
| WEATHERSTONE LAKES MHP | 221 | 0 |
| VICKSBURG FARM | 220 | 1 |
| CROWN KING WATER COMPANY | 203 | 7 |
| ORANGE ACRES RANCH | 200 | 5 |
| TONTO CREEK WATER COMPANY | 190 | 1 |
| AWC - CASA GRANDE SOUTH WATER COMPANY | 176 | 1 |
| TIMBER VILLAGE MOBILE HOME PK | 176 | 0 |
| SAGUARO ACRES CFD | 175 | 1 |
| ADVANCE MHP | 175 | 1 |
| SILVER CHOLLA LLC | 168 | 0 |
| CONWAY COMMONS MOBILE HOME PARK | 165 | 0 |
| MOUNTAIN VIEW MHP | 160 | 0 |
| HOPEVILLE WATER SYSTEM | 145 | 0 |
| NACO WATER CO BISBEE | 138 | 0 |
| PINE VIEW RV PARK | 138 | 1 |
| APACHE MOBILE HOME AND RV PARK, LLC | 130 | 13 |
| APACHE LAKE MARINA RESORT | 123 | 4 |
| PALOMA RANCH | 112 | 0 |
| ENCHANTED LAKES ESTATES | 107 | 0 |
| DOUBLE ROCK ESTATES | 105 | 0 |
| Salt River North Mesa | 100 | 0 |
| PEEKABOO WATER COOP | 100 | 7 |
| GUERNSEY LAKE MOBILE HOME COMMUNITY | 100 | 2 |
| SIGNAL PEAK WATER COMPANY | 99 | 0 |
| DOUBLE R WATER DISTRIBUTORS, INC. | 98 | 6 |
| BEARDSLEY WATER COMPANY 3 | 96 | 0 |
| GILBERT RIGG WELL COOP | 95 | 0 |
| WHITE TANK WELL INC | 87 | 0 |
| TRIPLE G DAIRY | 84 | 0 |
| SONTEL WATER COOP | 80 | 1 |
| EPCOR - RIO LINDO | 79 | 25 |
| TWO TANKS COMMUNITY WELL | 76 | 3 |
| BELMONT MOUNTAIN DAIRY | 72 | 1 |
| BUCKEYE ACRES MHP | 71 | 0 |
| SWAN LAKE RESORT | 70 | 4 |
| VALLEY VIEW WATER COMPANY | 60 | 6 |
| RANCHO WELLS INC | 59 | 2 |
| WEST END WATER COMPANY - WHEAT | 55 | 0 |
| GREENFIELD RANCHETTES | 53 | 11 |
| ASHLEY ROSE MHP | 50 | 4 |
| GRANDVIEW WATER COMPANY | 50 | 16 |
| CLEAR SPRINGS UTILITY WELL 6 | 48 | 3 |
| AUGUST HILLS MHP | 41 | 0 |
| 67 AVE PROPERTY OWNERS ASSOCIATION | 40 | 1 |
| Salt River Landfill | 38 | 0 |
| RIM COUNTRY ESTATES MHP | 36 | 2 |
| MEADOW RANCH WATER SYSTEM | 36 | 0 |
| OLIVE AVENUE HOA | 25 | 0 |
| G LAZY B MOBILE HOME PARK | 25 | 1 |
TRI Facilities (50)
Cities in Maricopa (21)
Frequently Asked Questions
What is the environmental risk level in Maricopa, Arizona? ▼
Are there Superfund sites in Maricopa? ▼
How many toxic release facilities are in Maricopa? ▼
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Is the drinking water safe in Maricopa? ▼
What environmental agencies cover Maricopa? ▼
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.