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Chertsey Water Hardness & Quality Report (2026)

Water Hardness

very hard

301+ mg/L

Very Hard

estimated · not lab-verified

Source

mixed

pH Level

8.4

neutral = 7.0

Lead

0.001 mg/L

✓ Below action level

TDS

530.6 mg/L

Est. Daily Cost

£0.85

energy & soap waste

Source: DWI Data Portal · Updated 2026

very hard301+ mg/LVery Hard · est.

0–99

mg/L

Soft

100–149

mg/L

Slightly Hard

150–199

mg/L

Moderately Hard

200–300

mg/L

Hard

300+

mg/L

Very Hard

Appliance Damage Report

In Chertsey, your appliances are currently losing 45% efficiency due to mineral buildup.

ApplianceIn ChertseySoft Water CityEfficiency 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 Chertsey compares to its nearest neighbours

CityHardnessClark°RiskSource
Chertsey, South East≈ 301+ mg/L28.1°🔴 Very Hardmixed
Addlestone, South East212.5 mg/L14.9°🟠 Hardmixed
Staines, South East≈ 200–300 mg/L15.1°🟠 Hardmixed
Weybridge, South East≈ 300+ mg/L14°🔴 Very Hardmixed
Shepperton, South East≈ 200–300 mg/L18.8°🟠 Hardmixed

National Benchmark

How Chertsey compares to the United Kingdom average

BenchmarkHardnessAppliance Risk
Chertsey≈ 301+ mg/L🔴 Very High
United Kingdom National Avg177 mg/L🟡 Moderate
Skipton Top Rated7.1 mg/L🟢 None

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What Makes Chertsey's Water Unique?

Local geology and source profile

Source: MixedTDS: 530.6 mg/LpH: 8.4

Chertsey receives its water from Thames Water Utilities Ltd. The supply is a mix, drawing from the River Thames at Walton and from groundwater sourced from the North Downs Chalk aquifer in the north Surrey zone. All water undergoes treatment at the Walton Water Treatment Works before being distributed to residents.

The water's hardness is primarily influenced by its geological origins. The North Downs Chalk formation, a significant aquifer, is composed of chalk bedrock. This bedrock is rich in calcium carbonate, which dissolves into the groundwater. Consequently, water drawn from this chalk aquifer is characterized as very hard, registering at 17.6°Clark.

Residents in Chertsey likely experience the effects of very hard water, which can lead to scale buildup in appliances like kettles and water heaters, potentially shortening their lifespan. You might notice reduced lathering from soaps and detergents. To combat scale, regular descaling of appliances is recommended. Using a water softener is often a practical solution for households struggling with the impacts of very hard water on plumbing and daily chores.

Geology & Source: Chalk aquifer; high calcium carbonate content from chalk bedrock yields very hard water

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Frequently Asked Questions

Is Chertsey's water safe to drink?
Yes. Chertsey's water meets all DWI drinking water standards. The hardness is ≈ 301+ 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 Chertsey?
At ≈ 301+ mg/L (Very Hard), Chertsey'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 Chertsey compare to the United Kingdom average?
The United Kingdom national average is 177 mg/L. Chertsey (≈ 301+ mg/L) is 224 mg/L above the national average. The softest major city is Skipton at just 7.1 mg/L.