Total Trihalomethanes (TTHM) in District of Columbia Drinking Water
District of Columbia has 48 public water systems. 19 have recorded total trihalomethanes (tthm) violations.
Total Systems
48
With Violations
19
EPA MCL
0.08
Population Served
701K
Total Trihalomethanes (TTHM) in District of Columbia: Key Facts
Total Water Systems
48
Systems with Violations
19
Lead Violations
2
Copper Violations
4
EPA Standard
0.08 mg/L
Water Systems with Violations in District of Columbia
| System | Population | Violations |
|---|---|---|
| PASCHAL SHERMAN INDIAN SCHOOL | 220 | 195 |
| WA HE LUT INDIAN SCHOOL | 175 | 114 |
| Eastern Navajo Agency - BIE | 455 | 112 |
| Chi Chil Tah Jones Ranch Community School - BIE | 137 | 94 |
| D.C. WATER AND SEWER AUTHORITY | 632K | 82 |
| JOINT BASE ANACOSTIA - BOLLING | 19K | 81 |
| Fort Wingate Community | 550 | 67 |
| Bread Springs Day School (New) - BIE | 115 | 66 |
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 District of Columbia water?
District of Columbia has 48 public water systems. 19 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 District of Columbia 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