Water Hardness in 94121
San Francisco, California · San Francisco County
Based on laboratory testing of treated tap water reported to state regulators. Updated periodically with the latest compliance data.
Our Estimate
Weighted average from 1 water system.
What This Means For You
Your Water Is Soft
Your water hardness is in the soft range. You likely don't need a water softener. Enjoy your naturally soft water!
Know your water hardness?
If you've tested your water or have your utility's CCR report, share your reading to help us improve accuracy for San Francisco, CA (94121).
Water Systems Serving 94121
Nearby Zip Codes
Frequently Asked Questions
Is the water hard in San Francisco, CA (94121)?
The average water hardness in 94121 is 9 PPM (0.5 GPG), which is classified as soft.
Do I need a water softener in 94121?
At 9 PPM, your water is relatively soft. A water softener is generally not necessary.
How many water systems serve 94121?
Zip code 94121 in San Francisco, California is served by 1 water system.
Learn More About Your Water
Water Hardness Scale: What PPM Means & When It Matters
Understand the USGS hardness scale, convert between PPM and GPG, and see real city examples at every hardness level.
10 min readHow to Test Water Hardness at Home (Free + DIY + Kit Methods)
From free online lookups to test strips and lab testing - every way to find out how hard your water is.
8 min read