Water Hardness and Quality in Sunbury West

Supplied by Thames Water · Sunbury West (NLW50)

Below Average

Sunbury West has hard water with quality that meets all UK drinking water standards.

Check a specific postcode in Sunbury West

Water Quality Scorecard

Total Hardness

Guideline: 150+ mg/l is considered hard

252mg/l CaCO₃
UK Average: 197.72 mg/l CaCO₃Above Average
LowAverageHigh

pH Level

UK Standard: 6.5 – 9.5

7.8pH units
UK Average: 7.43 pH unitsWell Above Average
LowAverageHigh

Free Chlorine

Guideline: below 1 mg/l

0.75mg/l
UK Average: 0.45 mg/lWell Above Average
LowAverageHigh

Nitrate

UK Standard: max 50 mg/l

24mg/l
UK Average: 16.9 mg/lAbove Average
LowAverageHigh

Lead

UK Standard: max 10 µg/l

1.2µg/l
UK Average: 1.08 µg/lWell Above Average
LowAverageHigh

Fluoride

UK Standard: max 1.5 mg/l

0.13mg/l
UK Average: 0.19 mg/lAbove Average
LowAverageHigh

Water Hardness in Sunbury West

Hardness is the most searched water quality metric. It affects limescale buildup in kettles, boilers, and pipes.

252mg/l CaCO₃Hard
Soft
Mod. Soft
Slightly Hard
Mod. Hard
Hard
Very Hard

Sunbury West has hard water at 252 mg/l. You will likely experience significant limescale buildup in kettles, boilers, and on bathroom surfaces. Many residents in your area use water softeners or anti-limescale products.

Water Source Information

Water Company
Thames Water
Supply Zone
Sunbury West (NLW50)
Source Type
River
Treatment Works
Sunbury West Treatment Works
Last Tested
2025-12-31
Data Source
Thames Water

Frequently Asked Questions

Is the water hard in Sunbury West?
Yes, Sunbury West has hard water at 252 mg/l CaCO₃. This is classified as "Hard" on the standard scale. You may notice limescale buildup in kettles and on taps.
Is Sunbury West tap water safe to drink?
Yes, tap water in Sunbury West is safe to drink. It is treated and tested by Thames Water and meets all UK Drinking Water Inspectorate standards. All tested parameters are within regulatory limits.
What is the water hardness in Sunbury West?
The water hardness in Sunbury West is 252 mg/l CaCO₃, which is classified as "Hard". This is above the UK national average of 170 mg/l.
Who supplies water to Sunbury West?
Water in Sunbury West is supplied by Thames Water, which serves the London and Thames Valley region. The water comes from river sources and is treated at Sunbury West Treatment Works.
Disclaimer: Water quality data is sourced from Thames Water and may not reflect real-time conditions. For health or medical decisions, please contact Thames Water directly or consult the Drinking Water Inspectorate at dwi.gov.uk. Data last updated: 2025-12-31.