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

The USA national average is 151 mg/L. Clayton (≈ 180+ mg/L) is 189 mg/L harder than average.

Clayton Water Hardness & Quality Report (2026)

Water Hardness

very hard

180+ mg/L

Very Hard

estimated · not lab-verified

Source

reservoir

pH Level

8.3

neutral = 7.0

Lead

0.008 mg/L

✓ Below action level

TDS

562.6 mg/L

Est. Daily Cost

$0.91

energy & soap waste

Source: See methodology section below · Updated 2026

very hard180+ mg/LVery Hard · 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 Clayton, your appliances are currently losing 45% efficiency due to mineral buildup.

Appliance	In Clayton	Soft Water City	Efficiency Loss
Kettle	4.7 yrs	8.5 yrs	-45%
Washing Machine	6.6 yrs	12 yrs	-45%
Water Heater	8.3 yrs	15 yrs	-45%

Regional Water Comparison

How Clayton compares to its nearest neighbours

City	Hardness	PFAS (ppt)	Risk	Source
▶ Clayton, California	≈ 180+ mg/L	7.3 ppt	🔴 Very Hard	reservoir
Bay Point, California	≈ 120–179 mg/L	5.5 ppt	🟠 Hard	mixed
Pittsburg, California	≈ 120–179 mg/L	0 ppt	🟠 Hard	reservoir
Concord, California	≈ 120–179 mg/L	0 ppt	🟠 Hard	reservoir
Pleasant Hill, California	≈ 0–60 mg/L	6.2 ppt	🟢 Soft	groundwater

National Benchmark

How Clayton compares to the USA average

Benchmark	Hardness	Appliance Risk
▶ Clayton	≈ 180+ mg/L	🔴 High
USA National Avg	151 mg/L	🟠 Moderate
Scarsdale Top Rated	0.02 mg/L	🟢 None

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What Makes Clayton's Water Unique?

Local geology and source profile

Source: ReservoirTDS: 562.6 mg/LpH: 8.3

Contra Costa Water District delivers treated drinking water to Clayton and nearby communities in Contra Costa County, California. Serving around 198,000 residents, their supply primarily comes from the Sacramento-San Joaquin River Delta. Water is pumped from the Delta and processed at CCWD's treatment facilities, including the Jones Water Treatment Plant, before distribution. A minor contribution might come from Clayton Palms Water, which buys surface water.

The Sacramento-San Joaquin Delta watershed covers more than 40,000 square miles, collecting drainage from the Sierra Nevada, Cascade Range, and Central Valley. Its geology is largely young alluvial sediments atop older sedimentary basins. Upstream, Mesozoic granitic intrusions and metavolcanics, fractured by faults, mix with Tertiary marine sandstones and shales, introducing dissolved minerals. The hardness itself originates from upstream dissolution in limestone-rich areas, leading to a hard water supply.

This very hard water significantly contributes to scale buildup within pipes, water heaters, dishwashers, and washing machines. Such buildup can slash appliance efficiency by up to 50% and shorten their operational lifespan. Boilers and fixtures are particularly vulnerable, as limescale can clog valves and heating elements, driving up energy costs. To combat this, regular vinegar descaling, installing scale inhibitors, or a water softener is advised. These measures help prevent damage, improve soap's lathering ability, and maintain mineral-balanced drinking water.

Geology & Source: Sacramento-San Joaquin River Delta watershed; Pleistocene/Holocene alluvial deposits; limestone/dolomite outcrops upstream contribute calcium/magnesium causing hardness

Other California Water Reports

Bay Point

≈ 120–179 mg/L

🟠 Hard

Pittsburg

≈ 120–179 mg/L

🟠 Hard

Concord

≈ 120–179 mg/L

🟠 Hard

Pleasant Hill

≈ 0–60 mg/L

🟢 Soft

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 Clayton's water safe to drink?

Yes. Clayton's water meets all federal safety standards. The hardness is ≈ 180+ mg/L (Very Hard), which is safe to drink. High hardness affects appliances and taste, but poses no health risk.

Do I need a water softener in Clayton?

At ≈ 180+ mg/L (Very Hard), Clayton'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 45%.

How does Clayton compare to the USA average?

The USA national average is 151 mg/L. Clayton (≈ 180+ mg/L) is 189 mg/L above the national average. The softest major city is Scarsdale at just 0.02 mg/L.

Data Sources & Methodology

Water quality data for Clayton 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.