Water Reports / CA
Los Angeles tap water, decoded.
Source: Los Angeles Department of Water and Power
Disinfectant
Chloramine
Hardness
Hard, varies by zone
TDS
300–500 ppm
Watch items
3
What to know about Los Angeles water
- +Chloramine disinfection across the system, which does not dissipate on standing and needs catalytic carbon to reduce.
- +Hard water from a blended supply of imported, groundwater, and recycled sources, so scale builds on fixtures and glass.
- +PFAS has been detected in some San Fernando Valley groundwater wells; the utility blends to stay under limits.
Hardness detail: ~8–12 grains per gallon.
For your shower
LA is the double case for a serious shower filter: persistent chloramine plus real hardness. Chloramine requires catalytic carbon with genuine contact time, and hard water is what dries out skin and dulls hair even when chemistry is handled.
For your glass
The blended supply means TDS and taste vary by neighborhood and season. Reverse osmosis is the reliable way to flatten that variability, stripping the blend to nothing and rebuilding a consistent mineral profile.
How we'd filter Los Angeles
This is the exact profile Monolith XL and Opus are built for: catalytic carbon depth for chloramine in the shower, tankless RO with remineralization for the glass, and dosing to restore what hardness and treatment stripped out.
Does Los Angeles use chlorine or chloramine?
Chloramine, system-wide. LADWP switched for distribution stability, which means the disinfectant reaches your tap at full strength and will not leave the water by sitting or boiling.
Is LA's water hard?
Yes, and it varies by zone, roughly 8 to 12 grains per gallon. The supply blends imported water, local groundwater, and recycled water, so hardness shifts by neighborhood.
Is there PFAS in LA tap water?
Some San Fernando Valley groundwater wells have shown PFAS detections. LADWP blends sources to remain below EPA limits, but point-of-use reverse osmosis is the recognized way to reduce PFAS at home.
More reports
Figures are drawn from each utility's most recent consumer confidence report and public statements. Water chemistry varies by season and neighborhood; your utility's annual report is the authoritative source for your address.