Water Hardness and Quality in Crawley
Supplied by Thames Water · Witney (OX18)
Crawley has hard water with quality that meets all UK drinking water standards.
Check a specific postcode in Crawley
Water Quality Scorecard
Total Hardness
Guideline: 150+ mg/l is considered hard
251mg/l CaCO₃
UK Average: 197.72 mg/l CaCO₃Above Average
LowAverageHigh
pH Level
UK Standard: 6.5 – 9.5
7.4pH units
UK Average: 7.43 pH unitsAverage
LowAverageHigh
Free Chlorine
Guideline: below 1 mg/l
0.5mg/l
UK Average: 0.45 mg/lAbove Average
LowAverageHigh
Nitrate
UK Standard: max 50 mg/l
17mg/l
UK Average: 16.9 mg/lAverage
LowAverageHigh
Lead
UK Standard: max 10 µg/l
0.9µg/l
UK Average: 1.08 µg/lAbove Average
LowAverageHigh
Fluoride
UK Standard: max 1.5 mg/l
0.11mg/l
UK Average: 0.19 mg/lAverage
LowAverageHigh
Water Hardness in Crawley
Hardness is the most searched water quality metric. It affects limescale buildup in kettles, boilers, and pipes.
251mg/l CaCO₃Hard
Soft
Mod. Soft
Slightly Hard
Mod. Hard
Hard
Very Hard
Crawley has hard water at 251 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
- Witney (OX18)
- Source Type
- Mixed
- Treatment Works
- Witney Treatment Works
- Last Tested
- 2025-12-31
- Data Source
- Thames Water
Frequently Asked Questions
Is the water hard in Crawley?▾
Yes, Crawley has hard water at 251 mg/l CaCO₃. This is classified as "Hard" on the standard scale. You may notice limescale buildup in kettles and on taps.
Is Crawley tap water safe to drink?▾
Yes, tap water in Crawley 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 Crawley?▾
The water hardness in Crawley is 251 mg/l CaCO₃, which is classified as "Hard". This is above the UK national average of 170 mg/l.
Who supplies water to Crawley?▾
Water in Crawley is supplied by Thames Water, which serves the London and Thames Valley region. The water comes from mixed sources and is treated at Witney Treatment Works.