Interim Enhanced Surface Water Treatment Rule violations in Arizona
30 active public water systems in Arizona had a Interim Enhanced Surface Water Treatment Rule violation in the past three years, 5 of them in the latest quarter of EPA's data. What Interim Enhanced Surface Water Treatment Rule is and why it matters.
Systems with a Interim Enhanced Surface Water Treatment Rule violation
Latest quarter first, then largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
CS Mohawk Utility Company Tacna · Yuma County |
243 | 8 | 0 | |
|
AZ State Parks Cattail Cove Lake Havasu City · Mohave County |
170 | 4 | 0 | |
|
CS Antelope Water Company Mohawk · Yuma County |
163 | 5 | 0 | |
|
Kohls Ranch Water Company Kohls Ranch · Gila County |
141 | 9 | 2 | |
|
Government Hill Water System Roosevelt · Gila County |
50 | 3 | 0 | |
|
Gilbert, Town of Gilbert · Maricopa County |
247,600 | 9 | 1 | |
|
Goodyear Water Department Goodyear · Maricopa County |
50,001 | 4 | 0 | |
|
Epcor Anthem Anthem · Maricopa County |
23,826 | 3 | 0 | |
|
Apache Junction Water District Apache Junction · Pinal County |
15,610 | 6 | 0 | |
|
Ak-Chin Village Ak-chin Village · County |
11,646 | 6 | 1 | |
|
Usmc Yuma Main System Yuma · Yuma County |
8,353 | 6 | 0 | |
|
Page City of Page · Coconino County |
7,445 | 3 | 1 | |
|
Morenci Water Elec CO Main Morenci · Greenlee County |
4,078 | 5 | 0 | |
|
Williams City of Williams · Coconino County |
3,145 | 7 | 1 | |
|
Wellton Town of Wellton · Yuma County |
3,000 | 10 | 1 | |
|
Tombstone City of Tombstone · Cochise County |
1,545 | 4 | 1 | |
|
Fredonia Town of Fredonia · Coconino County |
1,327 | 5 | 1 | |
|
Gcnra Lees Ferry Lees Ferry · Coconino County |
890 | 5 | 1 | |
|
Saguaro Lake Marina Saguaro Lake · Maricopa County |
450 | 2 | 0 | |
|
Camp Navajo Bellemont · Coconino County |
350 | 4 | 1 | |
|
Hidden Shores RV Village Imperial Dam · Yuma County |
324 | 3 | 0 | |
|
Antelope Union High School Yuma · Yuma County |
250 | 8 | 0 | |
|
Rim Trail Dwid Payson · Gila County |
200 | 9 | 3 | |
|
Cibola Water Improvement District Cibola · La Paz County |
197 | 8 | 2 | |
|
Mohawk Valley School District Roll · Yuma County |
171 | 7 | 0 | |
|
Apache Lake Marina Resort Apache Lake · Maricopa County |
123 | 5 | 0 | |
|
Lake Roosevelt Water Plant Roosevelt · Gila County |
100 | 4 | 1 | |
|
Pine Water Association Dwid Pine · Gila County |
100 | 7 | 5 | |
|
Bonita Creek Water Company Payson · Gila County |
67 | 9 | 1 | |
|
Destination at Oak Creek Oak Creek Canyon · Coconino County |
50 | 4 | 2 |
About this data
A system is counted once if any of its violations in the past three years involved Interim Enhanced Surface Water Treatment Rule, including monitoring and reporting lapses. Rules violated and status in the table are for the whole system, not Interim Enhanced Surface Water Treatment Rule alone.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Arizona records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet.