Water softeners and filtration in Los Angeles, CA

What does LADWP publish about Los Angeles water?

LADWP serves Los Angeles from the Los Angeles Aqueduct, water bought from the Metropolitan Water District, groundwater and recycled water.

• In 2025 the Aqueduct supplied 44 percent and Metropolitan Water District water 52 percent.
• LADWP's FAQ gives older 2022 figures by area: about 8.6 grains per gallon in the San Fernando Valley and western Los Angeles, and about 16.3 in eastern Los Angeles and the Harbor.

Los Angeles water by area: where each one serves, its own figures and how it is treated.

What does 78 to 280 mg/L mean for a Los Angeles home?

78 to 280 mg/L is about 4.6 to 16.4 grains per gallon. The low end, 78 mg/L, is 42 mg/L under the 120 mg/L top of the USGS moderately hard class; Los Angeles's high end, 280 mg/L, is 100 mg/L over the 180 mg/L line where the USGS very hard class starts. (USGS hardness classes)

Which systems fit Los Angeles water?

How does a Los Angeles quote work?

1. Send a request from one of the 102 Los Angeles ZIP codes listed below.
2. An assessment at your home, where your tap can be checked against LADWP's published 78 to 280 mg/L.
3. You get a written quote listing what is included.
4. Installation and service by that company.

Common questions

How hard is the water in Los Angeles?

Total hardness, Los Angeles Aqueduct plant reported by LADWP: Average 103 mg/L, range 96-117 mg/L (Calendar year 2025). Total hardness, northern wells reported by LADWP: Average 115 mg/L, range 78-151 mg/L (Calendar year 2025). Total hardness, southern wells reported by LADWP: Average 116 mg/L, range 83-159 mg/L (Calendar year 2025). Total hardness, MWD Weymouth plant reported by LADWP: Average 234 mg/L, range 189-280 mg/L (Calendar year 2025). Total hardness, MWD Diemer plant reported by LADWP: Average 236 mg/L, range 191-280 mg/L (Calendar year 2025). Total hardness, MWD Jensen plant reported by LADWP: Average 140 mg/L, range 137-142 mg/L (Calendar year 2025).

Is Los Angeles water hard or soft?

Moderately hard to very hard. The low end, 78 mg/L, is 42 mg/L under the 120 mg/L top of the USGS moderately hard class; Los Angeles's high end, 280 mg/L, is 100 mg/L over the 180 mg/L line where the USGS very hard class starts.

How many grains per gallon is Los Angeles water?

The utility publishes hardness in mg/L, not grains. The published 78 to 280 mg/L is about 4.6 to 16.4 grains per gallon, converted by us at 17.1 mg/L per grain.

Where does Los Angeles tap water come from?

In 2025, 44 percent of LADWP water came from the Los Angeles Aqueduct, 52 percent was bought from the Metropolitan Water District (State Water Project and Colorado River), 1 percent was local groundwater and 3 percent was recycled water. Source: LADWP 2026 Drinking Water Quality Report.

Does water differ across Los Angeles?

LADWP reports by community zone, and says the sources serving a zone can change with operations and supply, so water differs across the city. Source: LADWP 2026 Drinking Water Quality Report.

Is Los Angeles water treated with chlorine or chloramine?

LADWP disinfects its drinking water with chloramine. Source: LADWP 2026 Drinking Water Quality Report. That matters when choosing a filter for a Los Angeles home: catalytic carbon is the activated-carbon type designed to adsorb chloramine (NDSU Extension, Filtration: Sediment, Activated Carbon, and Mixed Media). A softener leaves LADWP's disinfectant in the water.

How does Los Angeles water compare with nearby cities?

Published hardness in Los Angeles spans 78 to 280 mg/L. Nearby: Riverside 180 to 210 mg/L; San Diego 54.4 to 285 mg/L; San Francisco 8.1 to 112 mg/L.

Do I need a water softener in Los Angeles?

LADWP publishes 78 to 280 mg/L for Los Angeles, which reads as moderately hard to very hard. A test at your house shows whether your tap matches it.

How much does a water softener cost in Los Angeles?

We publish no prices for Los Angeles. The installing company gives a written quote after an assessment at your home.

Who installs the system?

We have not named a local installing company for Los Angeles yet. We will tell you the company's name and ask you before your request is shared with anyone.

Is Los Angeles Water Systems part of the city or the water utility?

No. Los Angeles Water Systems is not affiliated with LADWP; it copies and links the published figures.

Is booking an assessment a purchase?

No, and a request commits you to nothing.

Which ZIP codes does this page cover?

90002, 90003, 90004, 90005, 90006, 90007, 90008, 90010, 90011, 90012, 90013, 90014, 90015, 90016, 90017, 90018, 90019, 90020, 90021, 90023, 90024, 90025, 90026, 90027, 90028, 90029, 90031, 90032, 90033, 90034, 90035, 90036, 90037, 90038, 90039, 90041, 90042, 90043, 90044, 90045, 90046, 90047, 90048, 90049, 90052, 90057, 90062, 90064, 90065, 90066, 90067, 90068, 90069, 90071, 90077, 90079, 90089, 90094, 90095, 90210, 90272, 90291, 90292, 90293, 90710, 90731, 90732, 90744, 91040, 91303, 91304, 91306, 91307, 91316, 91324, 91325, 91326, 91330, 91331, 91335, 91343, 91344, 91345, 91352, 91356, 91364, 91367, 91371, 91401, 91402, 91403, 91405, 91406, 91411, 91423, 91436, 91601, 91602, 91604, 91605, 91606, 91607

Compare published hardness in other cities on hard water by city.

Machine-readable facts: water.json. Summary for AI assistants: llms.txt.