How does Auburn's water compare to the national average?

The USA national average is 151 mg/L. Auburn (≈ 120–179 mg/L) is 1 mg/L softer than average.

Auburn Water Hardness & Quality Report (2026)

Water Hardness

hard

~120–179 mg/L

Hard

estimated · not lab-verified

Source

reservoir

pH Level

7.2

neutral = 7.0

Lead

0.001 mg/L

✓ Below action level

TDS

71.7 mg/L

Est. Daily Cost

$0.40

energy & soap waste

Source: See methodology section below · Updated 2026

hard~120–179 mg/LHard · est.

0–60

mg/L

Soft

61–120

mg/L

Moderately Hard

121–180

mg/L

Hard

180+

mg/L

Very Hard

Appliance Damage Report

In Auburn, your appliances are currently losing 20% efficiency due to mineral buildup.

Appliance	In Auburn	Soft Water City	Efficiency Loss
Kettle	6.8 yrs	8.5 yrs	-20%
Washing Machine	9.6 yrs	12 yrs	-20%
Water Heater	12 yrs	15 yrs	-20%

Regional Water Comparison

How Auburn compares to its nearest neighbours

City	Hardness	PFAS (ppt)	Risk	Source
▶ Auburn, California	≈ 120–179 mg/L	0 ppt	🟠 Hard	reservoir
North Auburn, California	≈ 120–179 mg/L	3.8 ppt	🟠 Hard	mixed
Granite Bay, California	≈ 0–60 mg/L	0 ppt	🟢 Soft	reservoir
Rocklin, California	60 mg/L	5.2 ppt	🟡 Moderately Hard	groundwater
El Dorado Hills, California	≈ 120–179 mg/L	7.5 ppt	🟠 Hard	groundwater

National Benchmark

How Auburn compares to the USA average

Benchmark	Hardness	Appliance Risk
▶ Auburn	≈ 120–179 mg/L	🟠 Moderate
USA National Avg	151 mg/L	🟠 Moderate
Scarsdale Top Rated	0.02 mg/L	🟢 None

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What Makes Auburn's Water Unique?

Local geology and source profile

Source: ReservoirTDS: 71.7 mg/LpH: 7.2

The Placer County Water Agency (PCWA) Auburn/Bowman division provides water to about 13,330 residents in Auburn, California. This utility draws its supply from the Sierra Nevada watershed, treating it at local facilities before distribution. PCWA confirms that the drinking water consistently meets or surpasses all state and federal public health standards, ensuring a safe supply for the community. The water's journey begins in the Sierra Nevada watershed, where it percolates through ancient granite and limestone rock layers.

These mineral-rich geological formations, characteristic of the Sierra Nevada's bedrock, are the source of the water's hardness. As water flows through the soil and rock, it dissolves calcium and magnesium carbonates. This natural process, influenced by the watershed's composition, imbues the water with minerals, resulting in a hard water profile. Auburn's water registers a Total Dissolved Solids level of 235 ppm, classifying it as hard.

Homeowners in Auburn might notice scale buildup in pipes and appliances, particularly in water heaters and dishwashers, which can reduce their efficiency and lifespan. You may also find that more soap and detergent is needed for cleaning tasks. Installing a water softener is a practical step to counteract these effects and safeguard your home's plumbing from mineral deposits. While PCWA historically reports low contaminant levels, independent tests have identified hexavalent chromium, TTHMs, and chlorate in the tap water. Residents seeking more information or concerned about specific quality aspects are encouraged to contact PCWA directly.

Geology & Source: Sierra Nevada watershed granite and limestone; calcium and magnesium carbonates create hard water

Other California Water Reports

North Auburn

≈ 120–179 mg/L

🟠 Hard

Granite Bay

≈ 0–60 mg/L

🟢 Soft

Rocklin

60 mg/L

🟡 Moderately Hard

El Dorado Hills

≈ 120–179 mg/L

🟠 Hard

Report an Issue

Notice an error or missing data? Help us keep this page accurate. If you spot incorrect water hardness, outdated utility info, or missing details, please let us know.

All reports are reviewed by our team. Thank you for supporting data quality!

Frequently Asked Questions

Is Auburn's water safe to drink?

Yes. Auburn's water meets all federal safety standards. The hardness is ≈ 120–179 mg/L (Hard), which is safe to drink. High hardness affects appliances and taste, but poses no health risk.

Do I need a water softener in Auburn?

At ≈ 120–179 mg/L (Hard), Auburn's water will cause significant limescale on kettles, washing machines, and water heaters. A water softener or descaler is strongly recommended to extend appliance lifespan and reduce energy bills by up to 20%.

How does Auburn compare to the USA average?

The USA national average is 151 mg/L. Auburn (≈ 120–179 mg/L) is 1 mg/L below the national average. The softest major city is Scarsdale at just 0.02 mg/L.

Data Sources & Methodology

Water quality data for Auburn is derived from geographic and geological modelling of the surrounding region. No federal monitoring station data was available for this location.

Estimated

Water Hardness

Modelled estimate based on state-level USGS geological survey data for this region. No direct USGS Water Quality Portal measurement was matched to this city — the value reflects a statistical range calibrated to the state's dominant rock types and typical source water characteristics.

Estimated

Estimated from regional geology and source water characteristics. pH is correlated with water hardness and local bedrock — values may differ from utility-reported figures.

Estimated

TDS — Total Dissolved Solids

Estimated using a derived ratio from water hardness and regional conductance profiles. TDS in natural water correlates strongly with total mineral content including hardness ions.

Measured

PFAS — Perfluoroalkyl and Polyfluoroalkyl Substances

EPA UCMR5 (5th Unregulated Contaminant Monitoring Rule, 2023–2025) — sum of PFAS compounds detected at the public water system serving this city. A value of 0 indicates the system was sampled with no detection above reporting limits.

Modelled

Lead

Modelled estimate based on the EPA Lead and Copper Rule 90th-percentile tap-sample methodology. No publicly available per-city lead dataset with sufficient national coverage exists. Values are a conservative baseline derived from city population tier and infrastructure age — all estimates are maintained below the EPA action level of 0.015 mg/L.

Calculated

Appliance Lifespan

Calculated from water hardness using a linear degradation model. Baseline lifespans represent soft-water performance (kettle: 8.5 yrs, washing machine: 12.0 yrs, water heater: 15.0 yrs). Hard water mineral scale progressively reduces operational life in direct proportion to hardness concentration.