Systems with a yearly average at or above an EPA-based study benchmark
0.8%1 of 132 active community water systems
All 132 systems had enough required samples to calculate a yearly average. 1 had at least one yearly average at or above a study benchmark; 131 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.
Check your area
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 Iowa
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) | 0 | 132 | 0.0% |
| PFOS: 4.05 ppt study benchmark (reproduces EPA classification around 4 ppt) | 0 | 132 | 0.0% |
| PFHxS: 15 ppt study benchmark (reproduces EPA classification around 10 ppt) | 1 | 132 | 0.8% |
| PFNA: 15 ppt study benchmark (reproduces EPA classification around 10 ppt) | 0 | 132 | 0.0% |
| HFPO-DA: 15 ppt study benchmark (reproduces EPA classification around 10 ppt) | 0 | 132 | 0.0% |
| Hazard Index: 1.5 study benchmark with at least two detected components (reproduces EPA classification around 1) | 1 | 132 | 0.8% |
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 |
|---|---|---|---|---|---|
| ADEL MUNICIPAL WATER WORKS | IA2503003 | 6,461 | Ground water | 1 | Below all study benchmarks |
| ALBIA MUNICIPAL WATER WORKS | IA6803010 | 3,721 | Surface water purchased | 1 | Below all study benchmarks |
| ALGONA MUNICIPAL UTILITIES | IA5502015 | 5,487 | Ground water | 1 | Below all study benchmarks |
| ALTOONA WATER SUPPLY | IA7707030 | 19,565 | Ground water | 3 | Below all study benchmarks |
| AMES WATER TREATMENT PLANT | IA8503039 | 55,177 | Ground water | 1 | Below all study benchmarks |
| ANAMOSA MUNICIPAL WATER SUPPLY | IA5307048 | 4,457 | Ground water | 1 | Below all study benchmarks |
| ANITA MUNICIPAL UTILITIES | IA1503053 | 972 | Ground water | 1 | Below all study benchmarks |
| ANKENY, CITY OF | IA7709053 | 76,207 | Surface water purchased | 2 | Below all study benchmarks |
| ASBURY MUNICIPAL WATER SYSTEM | IA3102001 | 5,943 | Ground water | 4 | Below all study benchmarks |
| ATLANTIC MUNICIPAL UTILITIES | IA1509074 | 7,252 | Ground water | 1 | Below all study benchmarks |
| BANCROFT WATER SUPPLY | IA5507085 | 711 | Ground water | 1 | Below all study benchmarks |
| BELLE PLAINE WATER DEPT | IA0610099 | 2,380 | Ground water | 1 | Below all study benchmarks |
| BONDURANT MUNI WATER SUPPLY | IA7717032 | 9,393 | Surface water purchased | 1 | Below all study benchmarks |
| BOONE WATER WORKS | IA0819033 | 12,704 | Groundwater under influence of surface water | 1 | Below all study benchmarks |
| BURLINGTON MUNICIPAL WATERWORKS | IA2909053 | 26,015 | Surface water | 1 | Below all study benchmarks |
| CAMBRIDGE WATER SUPPLY | IA8509069 | 832 | Ground water | 1 | Below all study benchmarks |
| CARROLL MUNICIPAL WATER SUPPLY | IA1415072 | 10,184 | Ground water | 1 | Below all study benchmarks |
| CEDAR FALLS MUNICIPAL WATER UTILITIES | IA0709084 | 40,713 | Ground water | 8 | Below all study benchmarks |
| CEDAR RAPIDS WATER DEPARTMENT | IA5715093 | 142,364 | Groundwater under influence of surface water | 2 | Below all study benchmarks |
| CHARITON MUNICIPAL WATER WORKS | IA5903011 | 4,381 | Surface water purchased | 1 | Below all study benchmarks |
| CHARLES CITY WATER SUPPLY | IA3405012 | 7,446 | Ground water | 1 | Below all study benchmarks |
| CHEROKEE WATER SUPPLY - PLANT 1 | IA1811020 | 5,199 | Ground water | 1 | Below all study benchmarks |
| CLARKSVILLE WATER SUPPLY | IA1228038 | 1,254 | Ground water | 1 | Below all study benchmarks |
| CLEAR LAKE WATER DEPARTMENT | IA1716076 | 7,687 | Ground water | 1 | Below all study benchmarks |
| CLERMONT WATER SUPPLY | IA3317047 | 586 | Ground water | 1 | Below all study benchmarks |
| CLIVE WATER DEPARTMENT | IA7720051 | 20,277 | Surface water purchased | 1 | Below all study benchmarks |
| CORALVILLE MUNI WATER SYSTEM | IA5208071 | 22,318 | Ground water | 1 | Below all study benchmarks |
| COUNCIL BLUFFS WATER WORKS | IA7820080 | 64,447 | Surface water | 2 | Below all study benchmarks |
| CRESCO WATERWORKS | IA4515087 | 3,913 | Ground water | 2 | Below all study benchmarks |
| CRESTON WATER SUPPLY | IA8816089 | 7,536 | Surface water | 1 | Below all study benchmarks |
| DE WITT WATER SUPPLY | IA2330036 | 5,514 | Ground water | 3 | Below all study benchmarks |
| DECORAH WATER DEPARTMENT | IA9630012 | 7,615 | Ground water | 6 | Below all study benchmarks |
| DENISON WATER SUPPLY | IA2424027 | 9,381 | Ground water | 1 | Below all study benchmarks |
| DES MOINES WATER WORKS | IA7727031 | 246,055 | Surface water purchased | 3 | Below all study benchmarks |
| DUBUQUE WATER WORKS | IA3126052 | 59,667 | Ground water | 1 | Below all study benchmarks |
| DYERSVILLE MUNICIPAL WATER CO | IA3130091 | 4,477 | Ground water | 2 | Below all study benchmarks |
| EAGLE GROVE WATER SUPPLY | IA9926096 | 3,601 | Ground water | 2 | Below all study benchmarks |
| EMMETSBURG MUNICIPAL WATER DEPARTMENT | IA7428021 | 3,733 | Ground water | 1 | Below all study benchmarks |
| FAIRFIELD WATER SUPPLY | IA5131033 | 9,821 | Ground water | 1 | Below all study benchmarks |
| FOREST CITY WATER SUPPLY | IA9525047 | 4,285 | Ground water | 1 | Below all study benchmarks |
| FORT DODGE WATER SUPPLY | IA9433050 | 25,874 | Ground water | 1 | Below all study benchmarks |
| FT MADISON MUNI WATER WORKS | IA5625062 | 11,087 | Ground water | 1 | Below all study benchmarks |
| GLENWOOD MUNICIPAL UTILITIES | IA6525090 | 5,449 | Ground water | 1 | Below all study benchmarks |
| GRIMES WATER SUPPLY | IA7736011 | 17,809 | Ground water | 1 | Below all study benchmarks |
| GRINNELL WATER DEPARTMENT | IA7930008 | 9,564 | Ground water | 1 | Below all study benchmarks |
| HAMPTON MUNI WATER WORKS | IA3544024 | 4,337 | Ground water | 1 | Below all study benchmarks |
| HARLAN MUNICIPAL UTILITIES | IA8335029 | 5,067 | Ground water | 1 | Below all study benchmarks |
| HIAWATHA WATER DEPT | IA5735045 | 7,183 | Ground water | 5 | Below all study benchmarks |
| HUMBOLDT MUNICIPAL WATER DEPT | IA4641064 | 4,792 | Groundwater under influence of surface water | 1 | Below all study benchmarks |
| HUXLEY WATERWORKS DEPT | IA8538066 | 4,244 | Ground water | 1 | Below all study benchmarks |
| IA REGIONAL UTILITIES ASSOC (WAVERLY) | IA0990701 | 37,820 | Ground water | 3 | Below all study benchmarks |
| INDEPENDENCE WATER DEPT | IA1037070 | 6,064 | Ground water | 4 | Below all study benchmarks |
| INDIANOLA WATER SUPPLY | IA9133075 | 15,833 | Ground water | 1 | Below all study benchmarks |
| IOWA CITY MHP LLC | IA5200601 | 280 | Ground water | 1 | Below all study benchmarks |
| IOWA FALLS WATER DEPARTMENT | IA4260097 | 5,146 | Ground water | 2 | Below all study benchmarks |
| IOWA LAKES REGIONAL WATER | IA2100701 | 6,755 | Ground water | 1 | Below all study benchmarks |
| IOWA LAKES REGIONAL WATER - LAKES AREA | IA3060001 | 9,021 | Surface water purchased | 3 | Below all study benchmarks |
| IOWA-AMERICAN WTR CO-CLINTON DISTRICT | IA2326048 | 24,769 | Ground water | 4 | Below all study benchmarks |
| ISU | IA8503528 | 42,000 | Ground water purchased | 1 | Below all study benchmarks |
| JEFFERSON WATER DEPARTMENT | IA3742004 | 4,182 | Ground water | 1 | Below all study benchmarks |
| JOHNSTON MUNICIPAL WATER SUPPLY | IA7740011 | 24,897 | Surface water purchased | 2 | Below all study benchmarks |
| KEOKUK MUNICIPAL WATER WORKS | IA5640019 | 9,900 | Surface water | 1 | Below all study benchmarks |
| KNOXVILLE WATER WORKS | IA6342036 | 8,400 | Ground water | 1 | Below all study benchmarks |
| LEMARS WATER DEPARTMENT | IA7540174 | 10,606 | Ground water | 1 | Below all study benchmarks |
| LYON-SIOUX RWS-BIG SIOUX | IA6000755 | 1,530 | Ground water | 3 | Below all study benchmarks |
| MAHASKA RURAL WATER SYSTEM, INC. | IA6273901 | 9,818 | Ground water | 1 | Below all study benchmarks |
| MANCHESTER WATER SUPPLY | IA2839021 | 5,077 | Ground water | 5 | Below all study benchmarks |
| MAQUOKETA MUNICIPAL WATER | IA4950029 | 6,128 | Ground water | 1 | Below all study benchmarks |
| MARION CO. RURAL WATER DISTRICT | IA6342711 | 5,687 | Ground water purchased | 2 | Below all study benchmarks |
| MARION MUNICIPAL WATER DEPT | IA5751035 | 41,623 | Ground water | 4 | Below all study benchmarks |
| MARSHALLTOWN WATER WORKS | IA6469042 | 27,680 | Ground water | 1 | Below all study benchmarks |
| MASON CITY WATER DEPARTMENT | IA1750048 | 27,338 | Ground water | 1 | Below all study benchmarks |
| MELCHER-DALLAS WATER SUPPLY | IA6300099 | 1,213 | Ground water | 1 | Below all study benchmarks |
| MONTICELLO WATER SUPPLY | IA5343098 | 4,040 | Ground water | 3 | Below all study benchmarks |
| MOUNT PLEASANT MUNICIPAL UTILITIES | IA4453016 | 9,274 | Ground water | 2 | Below all study benchmarks |
| MOUNT VERNON WATER SUPPLY | IA5758021 | 4,527 | Ground water | 2 | Below all study benchmarks |
| MUSCATINE POWER & WATER | IA7048001 | 25,516 | Ground water | 4 | Below all study benchmarks |
| NEVADA WATER SUPPLY | IA8562044 | 6,925 | Ground water | 1 | Below all study benchmarks |
| NEW HAMPTON WATER SUPPLY | IA1970051 | 3,494 | Ground water | 2 | Below all study benchmarks |
| NEWTON WATER SUPPLY | IA5059064 | 16,518 | Ground water | 1 | Below all study benchmarks |
| NORTH LIBERTY WATER SUPPLY | IA5252072 | 23,276 | Ground water | 1 | Below all study benchmarks |
| NORWALK WATER SUPPLY | IA9164078 | 14,334 | Surface water purchased | 1 | Below all study benchmarks |
| OKOBOJI WATER SUPPLY | IA3060091 | 776 | Surface water purchased | 1 | Below all study benchmarks |
| ONAWA MUNICIPAL WATER PLANT | IA6739095 | 2,906 | Ground water | 1 | Below all study benchmarks |
| ORANGE CITY MUNICIPAL WATER DEPARTMENT | IA8474097 | 6,267 | Ground water | 1 | Below all study benchmarks |
| OSAGE MUNICIPAL WATER SUPPLY | IA6663001 | 3,637 | Ground water | 4 | Below all study benchmarks |
| OSCEOLA RURAL WATER SYSTEM-NORTH | IA7227701 | 7,002 | Ground water | 1 | Below all study benchmarks |
| OSCEOLA WATER WORKS | IA2038038 | 5,503 | Surface water | 1 | Below all study benchmarks |
| OSKALOOSA MUNICIPAL WATER DEPT | IA6273005 | 12,808 | Groundwater under influence of surface water | 1 | Below all study benchmarks |
| PELLA WATER WORKS DEPARTMENT | IA6368033 | 11,052 | Ground water | 1 | Below all study benchmarks |
| PERRY MUNICIPAL WATER WORKS | IA2561036 | 7,836 | Ground water | 1 | Below all study benchmarks |
| POLK CITY WATER SUPPLY | IA7770050 | 6,533 | Surface water purchased | 1 | Below all study benchmarks |
| PORTSMOUTH WATER SUPPLY | IA8365052 | 189 | Surface water purchased | 1 | Below all study benchmarks |
| POWESHIEK WATER ASSOCIATION | IA8670701 | 13,920 | Ground water | 1 | Below all study benchmarks |
| RATHBUN REG WATER ASSN (FT MADISON) | IA0400901 | 11,840 | Surface water purchased | 2 | Below all study benchmarks |
| RED OAK WATER SUPPLY | IA6950075 | 5,596 | Ground water | 3 | Below all study benchmarks |
| REGIONAL WATER | IA8300184 | 4,132 | Surface water purchased | 1 | Below all study benchmarks |
| RIVERVIEW SUBDIVISION | IA7038301 | 37 | Ground water | 1 | Below all study benchmarks |
| ROCK VALLEY WATER SUPPLY | IA8482096 | 4,059 | Ground water | 1 | Below all study benchmarks |
| RURAL WATER SYSTEM #1 | IA8400722 | 3,428 | Groundwater under influence of surface water | 3 | Below all study benchmarks |
| SAC & FOX (MESKWAKI) IN IOWA | 070000003 | 4,765 | Ground water | 1 | Below all study benchmarks |
| SERGEANT BLUFF WATER SUPPLY | IA9774033 | 5,015 | Ground water | 1 | Below all study benchmarks |
| SHENANDOAH WATER DEPT | IA7383045 | 4,925 | Ground water | 1 | Below all study benchmarks |
| SIOUX CENTER MUNICIPAL WATER DEPARTMENT | IA8486053 | 8,231 | Ground water | 2 | Below all study benchmarks |
| SIOUX CITY WATER SUPPLY | IA9778054 | 85,791 | Groundwater under influence of surface water | 2 | At or above a study benchmark |
| SIRWA #2 (CRESTON) | IA8080701 | 20,793 | Surface water | 1 | Below all study benchmarks |
| SIRWA #3 (OSCEOLA) | IA2038701 | 4,080 | Surface water purchased | 1 | Below all study benchmarks |
| SOUTHEAST POLK RWD | IA7774701 | 7,565 | Surface water purchased | 1 | Below all study benchmarks |
| SOUTHERN SIOUX COUNTY RURAL WATER | IA8400733 | 5,420 | Ground water | 1 | Below all study benchmarks |
| SPENCER MUNICIPAL WATER UTILITY | IA2171071 | 11,325 | Ground water | 1 | Below all study benchmarks |
| SPIRIT LAKE WATERWORKS | IA3070078 | 6,167 | Surface water | 1 | Below all study benchmarks |
| STORM LAKE WATER TREATMENT PLANT | IA1178097 | 11,431 | Ground water | 1 | Below all study benchmarks |
| STORY CITY WATER DEPT | IA8584000 | 3,357 | Ground water | 1 | Below all study benchmarks |
| UNIVERSITY WATER SYSTEM | IA5225101 | 26,684 | Surface water | 1 | Below all study benchmarks |
| URBAN BLUFFS - NORTH | IA7820701 | 1,558 | Surface water purchased | 1 | Below all study benchmarks |
| URBANDALE WATER UTILITY | IA7780042 | 45,605 | Surface water purchased | 1 | Below all study benchmarks |
| VINTON MUNICIPAL WATER DEPT | IA0688053 | 4,938 | Ground water | 1 | Below all study benchmarks |
| WAPELLO RURAL WATER ASSOC. | IA9000742 | 17,263 | Surface water purchased | 3 | Below all study benchmarks |
| WARREN WATER DISTRICT | IA9133701 | 20,095 | Surface water purchased | 1 | Below all study benchmarks |
| WASHINGTON WATER DEPARTMENT | IA9271068 | 7,362 | Ground water | 1 | Below all study benchmarks |
| WATERLOO WATER WORKS | IA0790074 | 69,504 | Ground water | 9 | Below all study benchmarks |
| WAUKEE WATER SUPPLY | IA2573080 | 31,823 | Surface water purchased | 1 | Below all study benchmarks |
| WAUKON WATER DEPARTMENT | IA0398082 | 3,827 | Ground water | 2 | Below all study benchmarks |
| WAVERLY WATER DEPARTMENT | IA0990085 | 10,394 | Ground water | 4 | Below all study benchmarks |
| WEBSTER CITY WATER SUPPLY | IA4063094 | 7,825 | Ground water | 3 | Below all study benchmarks |
| WEST BURLINGTON MUNI. WATER SUPPLY | IA2985002 | 3,728 | Surface water purchased | 1 | Below all study benchmarks |
| WEST CENTRAL RWA-BOYER SYSTEM | IA1400903 | 1,715 | Ground water | 1 | Below all study benchmarks |
| WEST DES MOINES WATER WORKS | IA7785007 | 73,959 | Surface water purchased | 2 | Below all study benchmarks |
| WINTERSET MUNICIPAL WATERWORKS | IA6171029 | 5,428 | Surface water | 1 | Below all study benchmarks |
| XENIA RWD (BOONE) | IA0844006 | 4,975 | Purchased ground water under influence of surface water source | 1 | Below all study benchmarks |
| XENIA RWD (DES MOINES) | IA2573701 | 12,860 | Surface water purchased | 1 | Below all study benchmarks |
| XENIA RWD (WOODWARD) | IA2576705 | 3,465 | Surface water purchased | 2 | 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 Iowa's state-specific standards or determine compliance. Use the official state or territory drinking-water program for current regulatory information.