EPA SDWIS DataNew Hampshire

Total Trihalomethanes (TTHM) in New Hampshire Drinking Water

New Hampshire has 4,131 public water systems. 2871 have recorded total trihalomethanes (tthm) violations.

Total Systems

4,131

With Violations

2,871

EPA MCL

0.08

Population Served

1.2M

Total Trihalomethanes (TTHM) in New Hampshire: Key Facts

Total Water Systems

4,131

Systems with Violations

2,871

Lead Violations

482

Copper Violations

224

EPA Standard

0.08 mg/L

Water Systems with Violations in New Hampshire

SystemPopulationViolations
STEELE POND DEV241622
LOCKES LOCATION451357
WEST EPPING WATER CO INC181339
SEABROOK WATER DEPT14K1029
ERROL WATER WORKS/WEST183973
MORNINGSIDE DRIVE80934
VIEW POINT COOP248928
HEMLOCK HILLS12877

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 New Hampshire water?

New Hampshire has 4,131 public water systems. 2871 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 New Hampshire 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