Iowa Drinking Water Compliance Records
1,080 water systems serving 3,017,414 people. 11,846 historical EPA violation records in the Q2 2026 snapshot.
TapScore Compliance-History Grades
A
735
68%
B
239
22%
C
89
8%
D
13
1%
F
4
0%
1,080
Water Systems
3,017,414
Population Served
11,846
Historical Records
2,208
Health-Based (All Years)
Systems With the Most Recent EPA Records
MONTIPARK LLC
60 served169 historical records94 recent
C
GLENN OAKS ADDITION
58 served62 historical records21 recent
C
MCBRIDE POINTE THIRD MASTER MAINTENANCE
25 served27 historical records18 recent
F
GRINNELL WATER DEPARTMENT
9,564 served17 historical records15 recent
F
FOX VALLEY ACRES
36 served18 historical records14 recent
C
GAVIN ESTATES
52 served40 historical records11 recent
C
ILA CAMPUS LLC
68 served11 historical records11 recent
C
DAWSON WATER WORKS
116 served26 historical records10 recent
D
LADORA WATER SUPPLY
229 served15 historical records9 recent
C
VALLEY VIEW WATER ASSOCIATION
65 served27 historical records8 recent
C
Large Systems With No Recent Records
DES MOINES WATER WORKS
246,055 served18 historical records
A
IOWA-AMERICAN WTR CO-DAVENPORT
147,720 served5 historical records
A
CEDAR RAPIDS WATER DEPARTMENT
142,364 served7 historical records
A
ANKENY, CITY OF
76,207 served23 historical records
A
WEST DES MOINES WATER WORKS
73,959 served3 historical records
A
WATERLOO WATER WORKS
69,504 served14 historical records
A
IOWA CITY WATER DEPARTMENT
68,753 served38 historical records
A
COUNCIL BLUFFS WATER WORKS
64,447 served3 historical records
A
DUBUQUE WATER WORKS
59,667 served4 historical records
A
AMES WATER TREATMENT PLANT
55,177 served6 historical records
A
Largest Water Systems in Iowa
| Water System | Grade | Population | Historical Records |
|---|---|---|---|
| DES MOINES WATER WORKS | A | 246,055 | 18 |
| IOWA-AMERICAN WTR CO-DAVENPORT | A | 147,720 | 5 |
| CEDAR RAPIDS WATER DEPARTMENT | A | 142,364 | 7 |
| SIOUX CITY WATER SUPPLY | B | 85,791 | 26 |
| ANKENY, CITY OF | A | 76,207 | 23 |
| WEST DES MOINES WATER WORKS | A | 73,959 | 3 |
| WATERLOO WATER WORKS | A | 69,504 | 14 |
| IOWA CITY WATER DEPARTMENT | A | 68,753 | 38 |
| COUNCIL BLUFFS WATER WORKS | A | 64,447 | 3 |
| DUBUQUE WATER WORKS | A | 59,667 | 4 |
| AMES WATER TREATMENT PLANT | A | 55,177 | 6 |
| URBANDALE WATER UTILITY | A | 45,605 | 2 |
| ISU | A | 42,000 | 8 |
| MARION MUNICIPAL WATER DEPT | A | 41,623 | 7 |
| CEDAR FALLS MUNICIPAL WATER UTILITIES | A | 40,713 | 3 |
| IA REGIONAL UTILITIES ASSOC (WAVERLY) | A | 37,820 | 1 |
| RATHBUN REGIONAL WATER ASSN (RATHBUN) | A | 33,000 | 45 |
| WAUKEE WATER SUPPLY | A | 31,823 | 14 |
| MARSHALLTOWN WATER WORKS | A | 27,680 | 3 |
| MASON CITY WATER DEPARTMENT | B | 27,338 | 83 |
Contaminants in Iowa
Lead in IowaArsenic in IowaNitrate in IowaFluoride in IowaPFOS in IowaPFOA in IowaTHMs in IowaHAA5 in Iowa
Cities in Iowa
DES MOINES(12)DAVENPORT(16)CEDAR RAPIDS(19)IOWA CITY(33)AMES(6)SIOUX CITY(2)ANKENY(11)WEST DES MOINES(4)WATERLOO(1)COUNCIL BLUFFS(3)NEWTON(22)DUBUQUE(18)CENTERVILLE(5)WAVERLY(4)URBANDALE(2)MARION(5)OTTUMWA(3)CEDAR FALLS(3)CRESTON(6)INDIANOLA(5)MARSHALLTOWN(17)BURLINGTON(3)MUSCATINE(29)WAUKEE(2)FORT DODGE(21)BOUTON(6)SPENCER(7)MASON CITY(1)ALTOONA(2)JOHNSTON(2)CLINTON(2)OSKALOOSA(5)NORTH LIBERTY(4)CORALVILLE(6)FORT MADISON(2)TAMA(4)CLIVE(1)GRIMES(4)BROOKLYN(2)KNOXVILLE(8)NORWALK(2)GRINNELL(7)BOONE(5)MINBURN(2)STORM LAKE(8)CLARINDA(5)DENISON(2)PELLA(2)PERRY(2)MOUNT PLEASANT(2)LEMARS(1)LE MARS(1)FAIRFIELD(3)CARROLL(1)CHEROKEE(4)GRAETTINGER(2)KEOKUK(1)OSCEOLA(2)ELDRIDGE(5)BONDURANT(1)WASHINGTON(9)MAY CITY(2)MANNING(4)RED OAK(2)DECORAH(5)SIOUX CENTER(1)WEBSTER CITY(1)TIFFIN(2)CLEAR LAKE(2)ROCK RAPIDS(5)HIAWATHA(3)CHARLES CITY(1)ADEL(2)AVOCA(3)ATLANTIC(1)MAQUOKETA(3)NEVADA(1)STRATFORD(2)POLK CITY(2)MADRID(9)ROCK VALLEY(2)ORANGE CITY(1)INDEPENDENCE(3)SPIRIT LAKE(1)OELWEIN(2)IRETON(2)ASBURY(1)ESTHERVILLE(1)ANAMOSA(4)DEWITT(3)ALGONA(4)DE WITT(4)SHELDON(1)WOODWARD(3)GLENWOOD(2)WINTERSET(1)IOWA FALLS(2)SHENANDOAH(2)VINTON(2)MANCHESTER(1)