Utilities / California

California water hardness

6 California systems with a hardness figure read from an official page, each on the retrieval date printed against it below. This is not a list of every utility in California; it is the list of those whose published figure has been verified here.

Soft Soft 0–60

Moderately hard Moderate 61–120

Hard Hard 121–180

Very hard Very hard 181+

Oakland, CA 68.4 mg/L 4 gpg Moderately hard
Sacramento, CA 83 mg/L 4.9 gpg Moderately hard
Fresno, CA 89.3 mg/L 5.2 gpg Moderately hard
Los Angeles, CA 192 mg/L 11.2 gpg Very hard
San Diego, CA 276 mg/L 16 gpg Very hard
Anaheim, CA 300 mg/L 18 gpg Very hard

mg/L as calcium carbonate. Each classification band is drawn the same width, so the axis is not linear in mg/L.

California systems on the USGS classification. Each row links to that system's published figure, report year and conversion. Grains per gallon are the utility's own figure where it published one, and our conversion at 17.1 mg/L per grain where it did not.

Los Angeles, CA — Los Angeles Department of Water and Power 192 mg/L (11.2 gpg) Very hard Published range 93–291 mg/L. LADWP Water Quality FAQs, “How hard is my water?”. Retrieved 2026-10-17.
Oakland, CA — East Bay Municipal Utility District 68.4 mg/L (4 gpg) Moderately hard Published range 17.1–119.7 mg/L. EBMUD Water Quality FAQs, “What is the water hardness in grains per gallon (gpg)?”. Retrieved 2026-10-17.
San Diego, CA — City of San Diego Public Utilities Department 276 mg/L (16.1 gpg) Very hard Published range 272–284 mg/L. City of San Diego Public Utilities, Water Quality page, “Water Hardness” section. Retrieved 2026-10-17.
Sacramento, CA — City of Sacramento Department of Utilities 83 mg/L (4.9 gpg) Moderately hard City of Sacramento 2025 Consumer Confidence Report. Retrieved 2026-10-17.
Anaheim, CA — Anaheim Public Utilities 300 mg/L (17.5 gpg) Very hard Anaheim Public Utilities, “Water Hardness” page. Retrieved 2026-10-17.
Fresno, CA — City of Fresno Department of Public Utilities 89.3 mg/L (5.2 gpg) Moderately hard Published range 65–190 mg/L. City of Fresno Water Quality Annual Report 2024. Retrieved 2026-10-17.

If your California system is not above

Only 6 California systems have been transcribed here, so most California readers will not find theirs. Find the water system that serves you walks through the free EPA search that names your system and the EPA lookup that finds its annual report, which is the document that carries a hardness figure for your water. There is no ZIP-code hardness figure on this site, and that page explains why a ZIP code cannot carry one honestly: a ZIP code is a postal boundary and a water system is a pipe network, and they do not line up.

Other states with verified systems

All verified systems Convert a figure from your own report How to read a water quality report