EPA SDWIS DataLouisiana

Total Trihalomethanes (TTHM) in Louisiana Drinking Water

Louisiana has 5,089 public water systems. 3016 have recorded total trihalomethanes (tthm) violations.

Total Systems

5,089

With Violations

3,016

EPA MCL

0.08

Population Served

5.3M

Total Trihalomethanes (TTHM) in Louisiana: Key Facts

Total Water Systems

5,089

Systems with Violations

3,016

Lead Violations

40

Copper Violations

200

EPA Standard

0.08 mg/L

Water Systems with Violations in Louisiana

SystemPopulationViolations
EAST MOORINGSPORT WATER SYSTEM02267
TOWN OF FERRIDAY WATER SYSTEM4K2042
EAST COVE UTILITIES4501843
FAIRVIEW UNION WATER SYSTEM2K1589
HUDSON GAARS MILL WATER SYSTEM6601416
S AND J RV PARK871286
VILLAGE OF SIKES WATER SYSTEM6391279
VILLAGE OF CALVIN WATER SYSTEM5911195

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 Louisiana water?

Louisiana has 5,089 public water systems. 3016 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 Louisiana 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