EPA SDWIS DataOhio

Total Trihalomethanes (TTHM) in Ohio Drinking Water

Ohio has 16,365 public water systems. 8941 have recorded total trihalomethanes (tthm) violations.

Total Systems

16,365

With Violations

8,941

EPA MCL

0.08

Population Served

11.1M

Total Trihalomethanes (TTHM) in Ohio: Key Facts

Total Water Systems

16,365

Systems with Violations

8,941

Lead Violations

223

Copper Violations

1,665

EPA Standard

0.08 mg/L

Water Systems with Violations in Ohio

SystemPopulationViolations
RISINGSUN CHRISTIAN SCHOOL252808
LAMP LIGHTERS VILLAGE PWS602374
SONRISE CHURCH501786
SANDY BEACH TRAILER PARK1001644
FRONTIER CAMPGROUND1001580
THE MARFO COMPANY901447
WHISPERING WINDS MHC1001429
WOODBURY APARTMENTS PWS1201407

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 Ohio water?

Ohio has 16,365 public water systems. 8941 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 Ohio 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