Tapcensus

Combined Radium (-226 and -228) violations in Arizona

15 active public water systems in Arizona had a Combined Radium (-226 and -228) violation in the past three years, 4 of them in the latest quarter of EPA's data. What Combined Radium (-226 and -228) is and why it matters.

Health effects: Radium is a bone-seeking radionuclide that accumulates in skeletal tissue after ingestion. Long-term exposure increases the risk of bone cancer and leukemia. There is no safe threshold for ionizing radiation — the MCL is set at a level balancing risk reduction with treatment feasibility. Children are particularly vulnerable due to higher rates of bone growth and calcium uptake.

Systems with a Combined Radium (-226 and -228) violation

Latest quarter first, then largest first
SystemServesStatusRules violated, 3 yrUnresolved
ST Johns City of
Saint Johns · Apache County 		3,500 5 1
Scua Bylas
Bylas · County 		3,160 12 3
Ponderosa Park Dwid
Prescott · Yavapai County 		602 5 1
Ranch Water Service INC
Kingman · Mohave County 		135 7 1
Tucson City of
Tucson · Pima County 		732,906 3 0
GW Santa Cruz Water CO
Maricopa · Pinal County 		84,000 7 0
Bullhead City Mohave
Bullhead City · Mohave County 		36,330 13 1
Lago del Oro Water Company
Catalina · Pinal County 		18,132 2 0
City of Show Low
Show Low · Navajo County 		17,139 2 0
Epcor North East Agua Fria
Phoenix · Maricopa County 		14,723 2 0
Scua Upper Seven Mile
County 		8,478 12 3
Arizona Village
County 		3,211 10 2
Springerville Town of
Springerville · Apache County 		1,972 5 1
Shangri la Ranch
New River · Maricopa County 		345 6 2
Cocopah East
County 		280 3 0
About this data

A system is counted once if any of its violations in the past three years involved Combined Radium (-226 and -228), including monitoring and reporting lapses. Rules violated and status in the table are for the whole system, not Combined Radium (-226 and -228) 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.