Total Trihalomethanes (TTHM) in Oregon Drinking Water
Oregon has 6,071 public water systems. 4428 have recorded total trihalomethanes (tthm) violations.
Total Systems
6,071
With Violations
4,428
EPA MCL
0.08
Population Served
4.0M
Total Trihalomethanes (TTHM) in Oregon: Key Facts
Total Water Systems
6,071
Systems with Violations
4,428
Lead Violations
51
Copper Violations
240
EPA Standard
0.08 mg/L
Water Systems with Violations in Oregon
| System | Population | Violations |
|---|---|---|
| SANTIAM MEADOWS COMMUNITY WS | 40 | 1988 |
| HILAND WC - BEAR CREEK | 275 | 1799 |
| RIVER BEND WEST WATER | 24 | 1743 |
| GALICE SUBDIVISION WATER CO | 33 | 1619 |
| HILAND WC - BOULDER CREEK | 350 | 1380 |
| TROLLERS COVE WATER ASSN | 32 | 1224 |
| SPORTSMANS PARADISE MOTEL/TC | 52 | 1023 |
| INDIAN TRAIL WATER USERS ASSN | 75 | 981 |
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 Oregon water?
Oregon has 6,071 public water systems. 4428 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 Oregon 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
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