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

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

California Water Hardness & Quality Report (2026)

Water Hardness

hard

~120–179 mg/L

Hard

estimated · not lab-verified

Source

groundwater

pH Level

7.5

neutral = 7.0

Lead

0.002 mg/L

✓ Below action level

TDS

150.1 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 California, your appliances are currently losing 20% efficiency due to mineral buildup.

Appliance	In California	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 California compares to its nearest neighbours

City	Hardness	PFAS (ppt)	Risk	Source
▶ California, Maryland	≈ 120–179 mg/L	0 ppt	🟠 Hard	groundwater
Lexington Park, Maryland	≈ 120–179 mg/L	5.4 ppt	🟠 Hard	groundwater
Chesapeake Ranch Estates, Maryland	148 mg/L	8 ppt	🟠 Hard	reservoir
Chesapeake Ranch Estates-Drum Point, Maryland	≈ 60–120 mg/L	5 ppt	🟡 Moderately Hard	reservoir
Cambridge, Maryland	≈ 120–179 mg/L	0 ppt	🟠 Hard	groundwater

National Benchmark

How California compares to the USA average

Benchmark	Hardness	Appliance Risk
▶ California	≈ 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 California's Water Unique?

Local geology and source profile

Source: GroundwaterTDS: 150.1 mg/LpH: 7.5

The St. Mary’s County Metropolitan Commission supplies drinking water to California, Maryland, and other communities across St. Mary’s County, including Lexington Park and Charlotte Hall. This utility, serving around 50,000 customers, relies solely on groundwater drawn from deep wells. These wells tap into the Patapsco and Aquia Aquifers, with treatment taking place at facilities like the main water treatment plant situated near California, MD. MetCom has been operating since 1964, focusing its operations on extracting groundwater rather than utilizing any surface water sources. Residents experiencing service issues can reach out at 301-737-7400.

The groundwater originates in the coastal plain sub-basin of the Potomac River watershed. Recharge happens as precipitation filters through sandy soils, eventually reaching confined aquifers. Geologically, this area is characterized by the Cretaceous Patapsco Formation, composed of sands and clays, and the Aquia Formation, which consists of glauconitic sands containing fossil shells. These formations host confined aquifers that maintain artesian pressure. This specific geology naturally contributes to a hard water supply due to the dissolution of alkaline earth minerals found within the sedimentary deposits, resulting in water that is moderately mineralized when compared to softer surface water sources found in the Appalachian region.

Homeowners in areas with moderately hard water often notice scale buildup in appliances like water heaters, dishwashers, and washing machines, which can reduce their efficiency and shorten their lifespan. You might also see soap scum forming in sinks, noticeable spotting on glassware after washing, or experience drier skin and hair. To combat these effects, regular flushing of water heaters and using vinegar to descale appliances can help. For optimal protection of your plumbing and improved cleaning performance, installing a water softener or conditioner is generally recommended. MetCom's 2021 Annual Water Quality Report confirms they meet all EPA standards for pH, lead, and copper, with routine monitoring for disinfection byproducts, iron, and manganese.

Geology & Source: Patapsco Aquifer and Aquia Aquifer; Cretaceous-age sand, gravel, and clay formations; shell fragments and limestone inclusions lead to moderate hardness

Other Maryland Water Reports

Lexington Park

≈ 120–179 mg/L

🟠 Hard

Chesapeake Ranch Estates

148 mg/L

🟠 Hard

Chesapeake Ranch Estates-Drum Point

≈ 60–120 mg/L

🟡 Moderately Hard

Cambridge

≈ 120–179 mg/L

🟠 Hard

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Frequently Asked Questions

Is California's water safe to drink?

Yes. California'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 California?

At ≈ 120–179 mg/L (Hard), California'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 California compare to the USA average?

The USA national average is 151 mg/L. California (≈ 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 California 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.