WH

Water Hardness in Rio Oso, CA

California · 1 zip codes · 1 matched water system

55 PPM
3.2 GPG
Soft
0Soft60120180300+
Verified — State Lab Tested

City avg (weighted): 55 PPM

Dataset updated March 9, 20261 matched water system in the city rollupIndividual systems and ZIPs can differ. Methodology

System used for this reading
City Of Yuba City
CA5110002
Water source: surface water
Source year: 2024
Serves: 70,256
USGS environmental estimate: 206 PPM
Source context

How this city reading is built

This city reading is a weighted rollup across 1 matched water system and 1 ZIP code. Citywide readings are useful for comparison, but individual utility zones and ZIPs can differ.

Source basis
1 verified treated-water source
1 matched system total for this city; treated-water reports are prioritized when available.
Water source profile
Primarily surface water
Surface-water hardness can shift with reservoirs, runoff, season, and treatment. This profile is weighted by known population served across matched systems.
Data recency
Report years 2024
Dataset rebuilt March 9, 2026; individual utility reporting years can vary.

Hardness is a mineral-content reading, not a drinking-water safety rating. Use it for scale, appliance, and softener decisions; check your utility report or test your tap before sizing treatment equipment. See how we calculate local readings.

Water Systems in Rio Oso

These systems are matched to Rio Oso, CA. Citywide readings are useful for comparison, but the system serving a specific address may differ from the city average.

1 water system
PWSID is the public water system identifier. Data Source shows whether the hardness value comes from a treated-water report, USGS monitoring, or a local estimate; source year is shown when available.
City Of Yuba City
CA5110002
Soft
55 PPMsurface water70,256 servedVerified — State Lab Tested
Source water: 206 PPM

Zip Codes in Rio Oso, CA

9567455

What This Means For You

Recommendations are based on the displayed hardness reading. Confirm your tap reading before sizing or buying treatment equipment.

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 Rio Oso, CA.

Submit Your Data

Frequently Asked Questions

How hard is the water in Rio Oso, CA?

The citywide weighted average water hardness in Rio Oso, CA is 55 PPM (3.2 GPG), classified as soft. This is based on 1 matched water system.

Do I need a water softener in Rio Oso, CA?

At 55 PPM, the citywide average is relatively soft. A water softener is generally not necessary.

Is hard water in Rio Oso, CA safe to drink?

Water hardness itself is a mineral-content reading, not a drinking-water safety rating. Calcium and magnesium are naturally occurring minerals, but you should check your utility's Consumer Confidence Report for contaminant and compliance information.

How many water systems serve Rio Oso, CA?

Rio Oso, California is served by 1 matched water system across 1 zip code.

Learn More About Your Water

Water Hardness Scale: PPM and GPG Chart

Use the USGS water hardness scale to compare PPM, GPG, and mg/L levels from soft to very hard water.

10 min read

How to Test Water Hardness at Home

Compare free lookups, soap tests, test strips, liquid drop kits, and lab tests for measuring water hardness.

8 min read