Disinfection Byproduct
Total Trihalomethanes (TTHM) in your water
Health effects
TTHM form when chlorine used to disinfect water reacts with natural organic matter. Long-term exposure has been linked to increased cancer risk and to harm in pregnancy. Levels often rise in warmer months and in systems with more organic material.
The guideline vs. the legal limit
The federal legal limit is the maximum allowed by law. The EWG health guideline is what independent scientists consider safe — it is often far stricter.
Health guideline (EWG)
0.15 ppb
Federal legal limit (MCL)
80 ppb
Source: EWG Tap Water Database & EPA MCLs · 2026
What removes Total Trihalomethanes (TTHM)
Pentair / Pelican · Whole-House Filtration
Pentair Pelican PC600 Whole House Filter
- stages
- 2
- flow gpm
- 8
- media life
- 5yr / 600k gal
Pentair / Pelican · Whole-House Filtration
Pentair Pelican PC1000 Whole House Filter
- stages
- 2
- flow gpm
- 10
- media life
- 5yr / 1M gal
Waterdrop · Reverse Osmosis Systems
Waterdrop G3P800 Tankless RO (800 GPD)
- gpd
- 800
- stages
- 7
- tankless
- true
Aquasana · Whole-House Filtration
Aquasana Rhino Whole House Filter (1,000,000 gal)
- stages
- 4
- flow gpm
- 7
- filter life
- 10yr / 1M gal
GE Appliances (Haier) · Reverse Osmosis Systems
GE GXRV40TBN 5-Stage Reverse Osmosis
- gpd
- 14.76
- stages
- 5
- antimicrobial
- true
A.O. Smith · Reverse Osmosis Systems
A.O. Smith AO-US-RO-4000 4-Stage RO
- gpd
- 50
- stages
- 4
- fluoride pct
- 99
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Is Total Trihalomethanes (TTHM) in your water?
Check your city's public record, then book a free 30-minute test to confirm what's in your home.