Water softeners and filtration in San Francisco, CA

What does SFPUC publish about San Francisco water?

The SFPUC supplies San Francisco mostly from reservoirs, with Hetch Hetchy providing up to 85 percent.

What does 8.1 to 112 mg/L mean for a San Francisco home?

8.1 to 112 mg/L is about 0.5 to 6.5 grains per gallon. The low end, 8.1 mg/L, is 52 mg/L under the 60 mg/L top of the USGS soft class; San Francisco's high end, 112 mg/L, is 8 mg/L under the 120 mg/L top of the USGS moderately hard class. (USGS hardness classes)

Which systems fit San Francisco water?

How does a San Francisco quote work?

1. Send a request from one of the 28 San Francisco ZIP codes listed below.
2. An assessment at your home, where your tap can be checked against SFPUC's published 8.1 to 112 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 San Francisco?

Hardness reported by SFPUC: Average 62 ppm, range 8.1-112 ppm (Calendar year 2025).

Is San Francisco water hard or soft?

Soft to moderately hard. The low end, 8.1 mg/L, is 52 mg/L under the 60 mg/L top of the USGS soft class; San Francisco's high end, 112 mg/L, is 8 mg/L under the 120 mg/L top of the USGS moderately hard class.

How many grains per gallon is San Francisco water?

The utility publishes hardness in mg/L, not grains. The published 8.1 to 112 mg/L is about 0.5 to 6.5 grains per gallon, converted by us at 17.1 mg/L per grain.

Where does San Francisco tap water come from?

Hetch Hetchy Reservoir supplies up to 85 percent of San Francisco water each year, with the rest from Bay Area reservoirs and a small amount of local groundwater. Source: SFPUC 2025 Water Quality Report.

Does San Francisco water change over time?

SFPUC says blending different sources through the year gave varying water quality. Source: SFPUC 2025 Water Quality Report.

Is San Francisco water treated with chlorine or chloramine?

SFPUC disinfects with ultraviolet light and chlorine and keeps the water disinfected in the pipes with chloramine. Source: SFPUC 2025 Water Quality Report. That matters when choosing a filter for a San Francisco home: catalytic carbon is the activated-carbon type designed to adsorb chloramine (NDSU Extension, Filtration: Sediment, Activated Carbon, and Mixed Media). A softener leaves SFPUC's disinfectant in the water.

How does San Francisco water compare with nearby cities?

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

Do I need a water softener in San Francisco?

SFPUC publishes 8.1 to 112 mg/L for San Francisco, which reads as soft to moderately hard. A test at your house shows whether your tap matches it.

Is the water the same in every San Francisco home?

SFPUC publishes one figure for its whole system (Calendar year 2025).

How much does a water softener cost in San Francisco?

We publish no prices for San Francisco. 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 San Francisco yet. We will tell you the company's name and ask you before your request is shared with anyone.

Is San Francisco Water Systems part of the city or the water utility?

No. San Francisco Water Systems is not affiliated with SFPUC; 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?

94102, 94103, 94104, 94105, 94107, 94108, 94109, 94110, 94111, 94112, 94114, 94115, 94116, 94117, 94118, 94121, 94122, 94123, 94124, 94127, 94129, 94130, 94131, 94132, 94133, 94134, 94158, 94188

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

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