EPA SDWIS DataArizona

Total Trihalomethanes (TTHM) in Arizona Drinking Water

Arizona has 4,383 public water systems. 3189 have recorded total trihalomethanes (tthm) violations.

Total Systems

4,383

With Violations

3,189

EPA MCL

0.08

Population Served

7.7M

Total Trihalomethanes (TTHM) in Arizona: Key Facts

Total Water Systems

4,383

Systems with Violations

3,189

Lead Violations

31

Copper Violations

71

EPA Standard

0.08 mg/L

Water Systems with Violations in Arizona

SystemPopulationViolations
PUEBLO DEL SOL WATER COMPANY13K2721
BULLHEAD CITY MOHAVE36K2669
PEORIA CITY OF188K2461
TUCSON CITY OF733K2267
ORO VALLEY WATER UTILITY42K2191
BIG PARK WATER COMPANY7K2033
NOGALES CITY OF22K1954
FOOTHILLS WATER AND SEWER LLC32K1945

Health Effects of Total Trihalomethanes (TTHM) Exposure

Cancer risk

Long-term exposure increases bladder cancer risk

Reproductive effects

Some evidence of adverse pregnancy outcomes

Liver/kidney stress

High chronic exposure may stress liver and kidneys

Long-term exposure: increased risk of cancer (bladder). Some evidence of reproductive effects.

Frequently Asked Questions

Is there total trihalomethanes (tthm) in Arizona water?

Arizona has 4,383 public water systems. 3189 have recorded total trihalomethanes (tthm) violations based on EPA SDWIS data. If you are on a private well, your water is not covered by these regulations and should be tested independently.

How can I check my Arizona water for total trihalomethanes (tthm)?

Search for your water system using the WaterCheck system lookup, or contact your utility and request a copy of your Consumer Confidence Report (CCR). The CCR is published annually and lists all detected contaminants, their levels, and the EPA MCLs. For private wells, contact a state-certified lab for independent testing.

What is the EPA limit for total trihalomethanes (tthm)?

The EPA Maximum Contaminant Level (MCL) for total trihalomethanes (tthm) is 0.08 mg/L. Systems that exceed MCLs are required to notify customers and take corrective action.

Total Trihalomethanes (TTHM) at a Glance

Categorydisinfection byproduct
EPA MCL0.08 mg/L

Source

Byproduct of drinking water chlorination; reaction of chlorine with organic matter

How to Filter Total Trihalomethanes (TTHM)

  • +Activated carbon filters reduce TTHMs effectively
  • +Reverse osmosis also removes TTHMs
  • +Letting water sit uncovered may reduce some volatile TTHMs