Systems with a yearly average at or above an EPA-based study benchmark
2.4%5 of 205 active community water systems
All 205 systems had enough required samples to calculate a yearly average. 5 had at least one yearly average at or above a study benchmark; 200 did not.
EPA-based study benchmark: the unrounded cutoff this research uses to reproduce EPA’s January 2026 technical-assistance classification around the April 2024 federal levels. It is not a current standard or compliance finding and cannot determine household exposure or health risk.
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Find your water system
ZIP codes are used only to route visitors to public water systems that reported serving them. Confirm the actual provider using a water bill or utility record.
Compound summary
System counts in Missouri
Each count shows how many included water systems had a yearly average at or above the named study benchmark.
| Study benchmark | Systems at or above benchmark | Water systems included | Percent |
|---|---|---|---|
| PFOA: 4.05 ppt study benchmark (reproduces EPA classification around 4 ppt) | 1 | 205 | 0.5% |
| PFOS: 4.05 ppt study benchmark (reproduces EPA classification around 4 ppt) | 4 | 205 | 2.0% |
| PFHxS: 15 ppt study benchmark (reproduces EPA classification around 10 ppt) | 0 | 205 | 0.0% |
| PFNA: 15 ppt study benchmark (reproduces EPA classification around 10 ppt) | 0 | 205 | 0.0% |
| HFPO-DA: 15 ppt study benchmark (reproduces EPA classification around 10 ppt) | 0 | 205 | 0.0% |
| Hazard Index: 1.5 study benchmark with at least two detected components (reproduces EPA classification around 1) | 0 | 205 | 0.0% |
System directory
Community water systems with complete monitoring
“Complete monitoring” means at least one sampling location had all required samples needed for a yearly average. Each PWSID appears once, preventing double counting across ZIP associations.
| Public water system | PWSID | Population served | Primary source | Sampling locations | Study benchmark result |
|---|---|---|---|---|---|
| ADAIR COUNTY PWSD 1 | MO2024000 | 7,500 | Surface water purchased | 2 | Below all study benchmarks |
| ANDERSON PWS | MO5010016 | 1,961 | Ground water | 2 | Below all study benchmarks |
| ANDREW COUNTY PWSD 1 | MO1024004 | 6,042 | Ground water purchased | 1 | Below all study benchmarks |
| ANDREW COUNTY PWSD 2 | MO1024005 | 3,580 | Ground water purchased | 2 | Below all study benchmarks |
| ASHLAND PWS | MO3010033 | 4,999 | Ground water | 2 | Below all study benchmarks |
| AURORA VERONA | MO5010038 | 8,529 | Ground water | 4 | Below all study benchmarks |
| BARTON DADE CEDAR JASP COUNTYCONS PWSD 1 | MO5024023 | 9,523 | Ground water | 9 | Below all study benchmarks |
| BELTON PWS | MO1010061 | 23,598 | Surface water purchased | 1 | Below all study benchmarks |
| BLUE SPRINGS PWS | MO1010080 | 61,084 | Surface water purchased | 3 | Below all study benchmarks |
| BOLIVAR PWS | MO5010085 | 11,000 | Ground water | 5 | Below all study benchmarks |
| BONNE TERRE PRISON | MO4061410 | 3,500 | Ground water | 1 | Below all study benchmarks |
| BOONE COUNTY CONS PWSD 1 | MO3024055 | 24,700 | Ground water | 13 | Below all study benchmarks |
| BOONE COUNTY PWSD 4 | MO3024052 | 6,455 | Ground water | 6 | Below all study benchmarks |
| BOONE COUNTY PWSD 9 | MO3024058 | 15,035 | Ground water | 5 | Below all study benchmarks |
| BOONVILLE PWS | MO3010089 | 7,964 | Surface water | 1 | Below all study benchmarks |
| BOWLING GREEN PWS | MO2010093 | 4,195 | Surface water | 2 | Below all study benchmarks |
| BRANSON PWS | MO5010096 | 12,640 | Surface water | 8 | Below all study benchmarks |
| BROOKFIELD PWS | MO2010105 | 4,111 | Surface water | 1 | Below all study benchmarks |
| BUTLER COUNTY PWSD 1 | MO4024070 | 12,000 | Ground water | 5 | Below all study benchmarks |
| BUTLER PWS | MO1010118 | 4,219 | Surface water | 1 | Below all study benchmarks |
| CALIFORNIA PWS | MO3010124 | 4,423 | Ground water | 5 | Below all study benchmarks |
| CALLAWAY 2 WATER DISTRICT | MO3024085 | 13,080 | Ground water | 8 | Below all study benchmarks |
| CALLAWAY COUNTY PWSD 1 | MO3024084 | 9,840 | Ground water | 7 | Below all study benchmarks |
| CAMDEN COUNTY PWSD 4 HORSESHOE BEND | MO3021377 | 7,912 | Ground water | 5 | Below all study benchmarks |
| CAMDENTON PWS | MO3010130 | 3,960 | Ground water | 3 | At or above a study benchmark |
| CAMPBELL PWS | MO4010132 | 1,562 | Ground water | 2 | Below all study benchmarks |
| CANNON PWSD 1 | MO2024500 | 6,482 | Surface water purchased | 2 | Below all study benchmarks |
| CAPE GIRARDEAU PWS | MO4010136 | 39,941 | Ground water | 2 | Below all study benchmarks |
| CAPE PERRY COUNTY PWSD 1 SOUTH | MO4024096 | 8,545 | Ground water | 4 | Below all study benchmarks |
| CARL JUNCTION PWS | MO5010138 | 8,142 | Ground water | 7 | Below all study benchmarks |
| CARROLLTON PWS | MO2010140 | 3,514 | Ground water | 1 | Below all study benchmarks |
| CARTHAGE PWS | MO5010142 | 14,600 | Ground water | 2 | Below all study benchmarks |
| CARUTHERSVILLE PWS | MO4010143 | 5,518 | Ground water | 1 | Below all study benchmarks |
| CASS COUNTY PWSD 2 | MO1024114 | 4,650 | Surface water purchased | 1 | Below all study benchmarks |
| CASS COUNTY PWSD 9 | MO1024118 | 6,063 | Ground water purchased | 1 | Below all study benchmarks |
| CENTRALIA PWS | MO3010152 | 4,027 | Ground water | 1 | Below all study benchmarks |
| CHARITON LINN COUNTY PWSD 3 | MO2024128 | 5,200 | Surface water purchased | 2 | Below all study benchmarks |
| CHARLESTON PWS | MO4010160 | 5,900 | Ground water | 1 | Below all study benchmarks |
| CHILLICOTHE MUNICIPAL UTILITIES PWS | MO2010162 | 10,187 | Ground water | 1 | Below all study benchmarks |
| CIRCLE C MHP | MO6048106 | 75 | Ground water | 1 | At or above a study benchmark |
| CLARK COUNTY CONS PWSD 1 | MO2024138 | 7,140 | Ground water | 1 | Below all study benchmarks |
| CLAY COUNTY PWSD 3 | MO1024143 | 3,447 | Ground water | 2 | Below all study benchmarks |
| CLAY COUNTY PWSD 6 | MO1024146 | 4,912 | Surface water purchased | 1 | Below all study benchmarks |
| CLAY COUNTY PWSD 8 | MO1024149 | 2,243 | Surface water purchased | 1 | Below all study benchmarks |
| COLE CAMP PWS | MO3010180 | 1,150 | Ground water | 1 | Below all study benchmarks |
| COLE COUNTY PWSD 1 | MO3024159 | 16,548 | Ground water | 7 | Below all study benchmarks |
| COLE COUNTY PWSD 2 | MO3024160 | 13,107 | Ground water | 7 | Below all study benchmarks |
| COLUMBIA PWS | MO3010181 | 126,254 | Ground water | 1 | Below all study benchmarks |
| CRYSTAL CITY PWS | MO6010198 | 4,733 | Ground water | 2 | Below all study benchmarks |
| CUBA PWS | MO6010200 | 3,292 | Ground water | 5 | Below all study benchmarks |
| DEKALB COUNTY PWSD 1 | MO1024191 | 7,635 | Ground water purchased | 2 | Below all study benchmarks |
| DESLOGE PWS | MO4011441 | 5,034 | Ground water | 2 | Below all study benchmarks |
| DESOTO PWS | MO6010213 | 6,400 | Ground water | 2 | Below all study benchmarks |
| DEXTER PWS | MO4010216 | 8,200 | Ground water | 2 | Below all study benchmarks |
| DUNKLIN COUNTY PWSD 1 | MO4024206 | 4,307 | Ground water | 2 | Below all study benchmarks |
| EL DORADO SPRINGS PWS | MO5010241 | 3,593 | Ground water | 3 | Below all study benchmarks |
| ELDON PWS | MO3010240 | 4,895 | Ground water | 4 | Below all study benchmarks |
| ELLINGTON PWS | MO4010243 | 790 | Ground water | 1 | Below all study benchmarks |
| EXCELSIOR SPRINGS PWS | MO1010261 | 11,084 | Ground water | 1 | Below all study benchmarks |
| FARMINGTON CORRECTIONAL CENTER | MO4069041 | 3,500 | Ground water | 2 | Below all study benchmarks |
| FARMINGTON PWS | MO4010270 | 18,217 | Ground water | 14 | Below all study benchmarks |
| FESTUS PWS | MO6010276 | 13,000 | Purchased ground water under influence of surface water source | 1 | Below all study benchmarks |
| FORT LEONARD WOOD | MO3079500 | 34,000 | Surface water | 15 | Below all study benchmarks |
| FRANKLIN COUNTY PWSD 1 | MO6024211 | 3,500 | Ground water | 4 | Below all study benchmarks |
| FRANKLIN COUNTY PWSD 3 | MO6024213 | 8,250 | Ground water | 5 | Below all study benchmarks |
| FREDERICKTOWN PWS | MO4010290 | 4,429 | Surface water | 1 | Below all study benchmarks |
| FULTON PWS | MO3010296 | 12,600 | Ground water | 4 | Below all study benchmarks |
| GAINESVILLE PWS | MO5010297 | 742 | Ground water | 4 | Below all study benchmarks |
| GLADSTONE PWS | MO1010307 | 27,000 | Ground water | 1 | Below all study benchmarks |
| GRAIN VALLEY PWS | MO1010320 | 16,000 | Ground water purchased | 2 | Below all study benchmarks |
| GRUNDY COUNTY PWSD 1 | MO2024237 | 3,900 | Surface water purchased | 1 | Below all study benchmarks |
| HANNIBAL PWS | MO2010344 | 17,108 | Surface water | 1 | Below all study benchmarks |
| HARRISON COUNTY PWSD 2 | MO1024242 | 3,740 | Ground water | 1 | Below all study benchmarks |
| HARRISONVILLE PWS | MO1010349 | 10,019 | Surface water | 1 | Below all study benchmarks |
| HENRY COUNTY WATER COMPANY | MO1010177 | 11,373 | Surface water | 1 | Below all study benchmarks |
| HERCULANEUM PWS | MO6010359 | 5,000 | Purchased ground water under influence of surface water source | 3 | Below all study benchmarks |
| HIGGINSVILLE PWS | MO1010363 | 4,800 | Surface water | 1 | Below all study benchmarks |
| HOLIDAY HILLS RESORT | MO5190947 | 2,065 | Ground water | 2 | Below all study benchmarks |
| HOLLISTER PWS | MO5010374 | 4,426 | Ground water | 4 | Below all study benchmarks |
| HOWARD COUNTY PWSD 2 | MO2024261 | 1,165 | Ground water purchased | 1 | Below all study benchmarks |
| INDEPENDENCE PWS | MO1010399 | 120,000 | Ground water | 1 | Below all study benchmarks |
| JACKSON COUNTY PWSD 1 | MO1024275 | 24,500 | Ground water purchased | 1 | Below all study benchmarks |
| JACKSON COUNTY PWSD 12 | MO1024278 | 5,705 | Surface water purchased | 2 | Below all study benchmarks |
| JACKSON COUNTY PWSD 13 | MO1024279 | 9,700 | Ground water purchased | 1 | Below all study benchmarks |
| JACKSON COUNTY PWSD 15 | MO1024281 | 8,772 | Ground water purchased | 1 | Below all study benchmarks |
| JACKSON COUNTY PWSD 16 | MO1020869 | 4,075 | Ground water purchased | 1 | Below all study benchmarks |
| JACKSON COUNTY PWSD 2 | MO1024276 | 16,440 | Surface water purchased | 2 | Below all study benchmarks |
| JACKSON PWS | MO4010404 | 15,000 | Ground water | 3 | Below all study benchmarks |
| JASPER COUNTY PWSD 1 | MO5024286 | 5,500 | Ground water | 4 | Below all study benchmarks |
| JEFFERSON CO PWSD 8 | MO6024300 | 4,733 | Ground water | 3 | Below all study benchmarks |
| JEFFERSON COUNTY CONS PWSD C 1 | MO6024295 | 37,000 | Surface water purchased | 1 | Below all study benchmarks |
| JEFFERSON COUNTY PWSD 5 | MO6024296 | 8,000 | Ground water | 5 | Below all study benchmarks |
| JEFFERSON COUNTY PWSD 6 | MO6024298 | 7,500 | Ground water | 5 | Below all study benchmarks |
| JEFFERSON COUNTY PWSD 7 | MO6024299 | 6,100 | Ground water | 5 | Below all study benchmarks |
| JEFFERSON COUNTY PWSD 1 | MO6024292 | 21,113 | Surface water purchased | 1 | Below all study benchmarks |
| JEFFERSON COUNTY PWSD 10 | MO6024302 | 10,000 | Surface water purchased | 1 | Below all study benchmarks |
| JEFFERSON COUNTY PWSD 2 | MO6024293 | 16,548 | Surface water | 2 | Below all study benchmarks |
| JEFFERSON COUNTY PWSD 3 | MO6024294 | 17,000 | Surface water purchased | 1 | Below all study benchmarks |
| JOHNSON COUNTY PWSD 1 | MO1024309 | 3,730 | Ground water | 1 | Below all study benchmarks |
| JOHNSON COUNTY PWSD 2 | MO1024310 | 12,490 | Ground water | 1 | Below all study benchmarks |
| JOHNSON COUNTY PWSD 3 | MO1024311 | 4,700 | Ground water | 2 | Below all study benchmarks |
| KANSAS CITY PWS | MO1010415 | 553,295 | Surface water | 2 | Below all study benchmarks |
| KEARNEY PWS | MO1010416 | 11,500 | Surface water purchased | 2 | Below all study benchmarks |
| KENNETT PWS | MO4010417 | 10,200 | Ground water | 1 | Below all study benchmarks |
| KIRKSVILLE PWS | MO2010429 | 17,566 | Surface water | 1 | Below all study benchmarks |
| KIRKWOOD PWS | MO6010430 | 28,000 | Surface water purchased | 1 | Below all study benchmarks |
| KNOX COUNTY PUBLIC WATER & SEWER DIST 1 | MO2024313 | 3,947 | Surface water purchased | 3 | Below all study benchmarks |
| LACLEDE COUNTY PWSD 1 | MO5024317 | 8,550 | Ground water | 5 | Below all study benchmarks |
| LACLEDE COUNTY PWSD 3 | MO5024319 | 6,075 | Ground water | 7 | Below all study benchmarks |
| LAF JO SALINE COUNTY CONS PWSD 2 | MO1024326 | 7,180 | Surface water purchased | 5 | Below all study benchmarks |
| LAFAYETTE COUNTY PWSD 1 | MO1024324 | 8,250 | Ground water purchased | 1 | Below all study benchmarks |
| LAMAR PWS | MO5010446 | 4,500 | Surface water | 1 | Below all study benchmarks |
| LEBANON PWS | MO5010458 | 15,442 | Ground water | 6 | Below all study benchmarks |
| LEES SUMMIT PWS | MO1010459 | 99,400 | Surface water purchased | 2 | Below all study benchmarks |
| LEXINGTON PWS | MO1010464 | 4,729 | Ground water | 1 | Below all study benchmarks |
| LINCOLN COUNTY PWSD 1 | MO6024340 | 14,000 | Ground water | 5 | Below all study benchmarks |
| MACON CO PWSD 1 | MO2024363 | 12,865 | Surface water purchased | 4 | Below all study benchmarks |
| MACON PWS | MO2010487 | 5,489 | Surface water | 1 | Below all study benchmarks |
| MALDEN PWS | MO4010490 | 3,706 | Ground water | 3 | Below all study benchmarks |
| MARION COUNTY PWSD 1 | MO2024377 | 4,900 | Surface water purchased | 4 | Below all study benchmarks |
| MARSHALL PWS | MO2010502 | 12,934 | Ground water | 1 | Below all study benchmarks |
| MARSHFIELD PWS | MO5010503 | 7,425 | Ground water | 3 | Below all study benchmarks |
| MERCER COUNTY PWSD 1 | MO2024382 | 3,200 | Surface water purchased | 3 | Below all study benchmarks |
| MO AMERICAN JEFFERSON CITY DISTRICT | MO3010409 | 30,075 | Surface water | 1 | Below all study benchmarks |
| MO AMERICAN JOPLIN | MO5010413 | 73,728 | Surface water | 8 | Below all study benchmarks |
| MO AMERICAN MEXICO | MO2010519 | 13,000 | Ground water | 1 | Below all study benchmarks |
| MO AMERICAN PLATTE COUNTY | MO1010625 | 16,645 | Ground water | 1 | Below all study benchmarks |
| MO AMERICAN ST JOSEPH | MO1010714 | 89,171 | Ground water | 1 | Below all study benchmarks |
| MO AMERICAN ST LOUIS ST CHARLES COUNTIES | MO6010716 | 1,111,000 | Surface water | 6 | Below all study benchmarks |
| MO AMERICAN TRI STATE | MO5024601 | 8,680 | Ground water | 3 | Below all study benchmarks |
| MO AMERICAN WARRENSBURG | MO1010833 | 18,500 | Ground water | 1 | Below all study benchmarks |
| MOBERLY PWS | MO2010533 | 13,783 | Surface water | 1 | Below all study benchmarks |
| MONETT PWS | MO5010537 | 9,789 | Ground water | 11 | Below all study benchmarks |
| MONROE CITY PWS, MO | MO2010538 | 2,500 | Surface water | 1 | Below all study benchmarks |
| MONROE COUNTY PWSD 2 | MO2024402 | 6,700 | Surface water purchased | 1 | Below all study benchmarks |
| MOUND CITY PWS | MO1010548 | 1,159 | Ground water | 1 | Below all study benchmarks |
| MOUNT VERNON PWS | MO5010553 | 4,575 | Ground water | 5 | Below all study benchmarks |
| NEVADA PWS | MO5010562 | 8,198 | Ground water | 1 | Below all study benchmarks |
| NIXA PWS | MO5010576 | 24,532 | Ground water | 9 | Below all study benchmarks |
| NODAWAY COUNTY PWSD 1 | MO1024428 | 6,428 | Surface water purchased | 1 | Below all study benchmarks |
| NORTH KANSAS CITY PWS | MO1010580 | 4,500 | Ground water | 1 | Below all study benchmarks |
| OAK GROVE PWS | MO1010589 | 8,289 | Ground water purchased | 1 | Below all study benchmarks |
| ODESSA PWS | MO1010599 | 5,202 | Ground water | 1 | Below all study benchmarks |
| OFALLON PWS | MO6010588 | 32,515 | Surface water purchased | 5 | Below all study benchmarks |
| OZARK PWS | MO5010619 | 22,000 | Ground water | 12 | Below all study benchmarks |
| PACIFIC PWS | MO6010620 | 6,000 | Ground water | 3 | Below all study benchmarks |
| PALMYRA PWS | MO2010623 | 3,595 | Ground water | 1 | Below all study benchmarks |
| PARK HILLS PWS | MO4010279 | 8,587 | Ground water | 1 | Below all study benchmarks |
| PARK PLACE MASTER ASSN | MO3282326 | 545 | Ground water | 1 | Below all study benchmarks |
| PECULIAR PWS | MO1010633 | 6,226 | Surface water purchased | 1 | Below all study benchmarks |
| PEMISCOT COUNTY CON PWSD 1 | MO4024448 | 6,042 | Ground water | 4 | Below all study benchmarks |
| PERRYVILLE PWS | MO4010636 | 8,555 | Surface water | 5 | Below all study benchmarks |
| PIKE COUNTY PWSD 1 | MO2024471 | 7,590 | Surface water purchased | 2 | Below all study benchmarks |
| PILOT GROVE PWS | MO3010642 | 768 | Ground water | 1 | Below all study benchmarks |
| PLATTE CITY PWS | MO1010646 | 4,691 | Surface water purchased | 1 | Below all study benchmarks |
| PLATTE CO PWSD 4 | MO1024478 | 9,552 | Surface water purchased | 2 | Below all study benchmarks |
| PLATTE COUNTY CONS PWSD 1 | MO1024479 | 7,074 | Surface water purchased | 1 | Below all study benchmarks |
| PLEASANT HILL PWS | MO1010649 | 8,262 | Surface water purchased | 2 | Below all study benchmarks |
| POPLAR BLUFF PWS | MO4010656 | 17,043 | Surface water | 1 | Below all study benchmarks |
| PULASKI COUNTY PWSD 1 | MO3024490 | 4,000 | Ground water | 5 | Below all study benchmarks |
| PULASKI COUNTY PWSD 2 | MO3024491 | 8,038 | Ground water | 6 | Below all study benchmarks |
| RAY COUNTY CONS PWSD 2 | MO1024511 | 9,360 | Ground water | 1 | Below all study benchmarks |
| RAYMORE PWS | MO1010675 | 21,517 | Surface water purchased | 2 | Below all study benchmarks |
| RAYTOWN WATER COMPANY | MO1010676 | 17,066 | Surface water purchased | 1 | Below all study benchmarks |
| REPUBLIC PWS | MO5010681 | 16,100 | Ground water | 4 | Below all study benchmarks |
| RICHMOND PWS | MO1010685 | 5,797 | Ground water | 1 | Below all study benchmarks |
| ROLLA PWS | MO3010700 | 20,800 | Ground water | 18 | Below all study benchmarks |
| S K & M WATER AND SEWER COMPANY | MO4036226 | 750 | Ground water | 2 | Below all study benchmarks |
| SALEM PWS | MO4010721 | 4,736 | Ground water | 4 | Below all study benchmarks |
| SAVANNAH PWS | MO1010724 | 5,249 | Ground water | 1 | Below all study benchmarks |
| SCHUYLER COUNTY CONSOLIDATED PWSD 1 | MO2024559 | 3,482 | Surface water purchased | 1 | Below all study benchmarks |
| SCOTLAND COUNTY CONS PWSD 1 | MO2024565 | 3,360 | Surface water purchased | 1 | Below all study benchmarks |
| SEDALIA PWS | MO3010728 | 21,725 | Ground water | 5 | Below all study benchmarks |
| SHELBYVILLE PWS | MO2010737 | 552 | Surface water purchased | 1 | Below all study benchmarks |
| SIKESTON PWS | MO4010743 | 16,291 | Ground water | 3 | Below all study benchmarks |
| SPRINGFIELD PWS | MO5010754 | 210,898 | Surface water | 3 | Below all study benchmarks |
| ST CHARLES CO PWSD #2 WRIGHT CITY | MO6010874 | 3,550 | Ground water | 2 | Below all study benchmarks |
| ST CHARLES COUNTY PWSD 2 | MO6024530 | 100,587 | Surface water purchased | 4 | Below all study benchmarks |
| ST CHARLES PWS | MO6010707 | 78,961 | Surface water purchased | 2 | Below all study benchmarks |
| ST CLAIR PWS | MO6010708 | 4,700 | Ground water | 7 | Below all study benchmarks |
| ST JAMES PWS | MO3010712 | 3,935 | Ground water | 4 | At or above a study benchmark |
| ST LOUIS CITY PWS | MO6010715 | 304,709 | Surface water | 2 | Below all study benchmarks |
| ST PETERS PWS | MO6010719 | 52,575 | Surface water purchased | 2 | At or above a study benchmark |
| ST ROBERT PWS | MO3010720 | 5,192 | Ground water | 6 | At or above a study benchmark |
| STE GENEVIEVE COUNTY PWSD 1 SC | MO4024543 | 3,718 | Ground water | 5 | Below all study benchmarks |
| STE GENEVIEVE PWS | MO4010710 | 4,999 | Ground water | 1 | Below all study benchmarks |
| SULLIVAN PWS | MO6010775 | 7,081 | Ground water | 7 | Below all study benchmarks |
| TANEY COUNTY PWSD 2 | MO5024600 | 6,250 | Ground water | 5 | Below all study benchmarks |
| TANEY COUNTY PWSD 3 | MO5024602 | 6,000 | Ground water | 10 | Below all study benchmarks |
| TIPTON PWS | MO3010791 | 2,861 | Ground water | 2 | Below all study benchmarks |
| TREEHOUSE CONDOMINIUMS | MO5036352 | 445 | Ground water | 2 | Below all study benchmarks |
| TRENTON MUNICIPAL UTILITIES PWS | MO2010796 | 5,600 | Surface water | 1 | Below all study benchmarks |
| TROY PWS | MO6010798 | 15,000 | Ground water | 5 | Below all study benchmarks |
| UNION PWS | MO6010801 | 12,348 | Ground water | 6 | Below all study benchmarks |
| UNIVERSITY OF MISSOURI COLUMBIA | MO3069001 | 40,000 | Ground water | 5 | Below all study benchmarks |
| VERNON COUNTY CONS PWSD 1 | MO5024618 | 9,615 | Ground water | 4 | Below all study benchmarks |
| WARRENTON PWS | MO6010834 | 8,208 | Ground water | 5 | Below all study benchmarks |
| WASHINGTON PWS | MO6010838 | 14,068 | Ground water | 10 | Below all study benchmarks |
| WAYNESVILLE PWS | MO3010841 | 5,460 | Ground water | 7 | Below all study benchmarks |
| WEBB CITY PWS | MO5010844 | 13,404 | Surface water purchased | 7 | Below all study benchmarks |
| WEST PLAINS PWS | MO4010853 | 12,864 | Groundwater under influence of surface water | 1 | Below all study benchmarks |
| WESTMIER SUBDIVISION | MO6031324 | 90 | Ground water | 1 | Below all study benchmarks |
| WHITEMAN AIR BASE | MO1079501 | 10,106 | Ground water | 1 | Below all study benchmarks |
| WILLARD PWS | MO5010860 | 8,400 | Ground water | 4 | Below all study benchmarks |
| Wentzville | MO6010849 | 41,784 | Ground water | 3 | Below all study benchmarks |
How the count works
What is included
Each active community water system with enough required samples for a yearly average is counted once, even if it is linked with several ZIP codes. This does not mean every home was tested. Private wells are excluded, and UCMR 5 did not comprehensively monitor every small system. This page does not apply Missouri's state-specific standards or determine compliance. Use the official state or territory drinking-water program for current regulatory information.