Water Hardness and Quality in South Croydon
Supplied by Thames Water · Croydon East (SLE1)
South Croydon has very hard water with quality that meets all UK drinking water standards.
Check a specific postcode in South Croydon
Water Quality Scorecard
Total Hardness
Guideline: 150+ mg/l is considered hard
303mg/l CaCO₃
UK Average: 197.72 mg/l CaCO₃Well Above Average
LowAverageHigh
pH Level
UK Standard: 6.5 – 9.5
7.3pH units
UK Average: 7.43 pH unitsBelow Average
LowAverageHigh
Free Chlorine
Guideline: below 1 mg/l
0.49mg/l
UK Average: 0.45 mg/lAverage
LowAverageHigh
Nitrate
UK Standard: max 50 mg/l
23mg/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
0.08mg/l
UK Average: 0.19 mg/lBelow Average
LowAverageHigh
Water Hardness in South Croydon
Hardness is the most searched water quality metric. It affects limescale buildup in kettles, boilers, and pipes.
303mg/l CaCO₃Very Hard
Soft
Mod. Soft
Slightly Hard
Mod. Hard
Hard
Very Hard
South Croydon has hard water at 303 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
- Croydon East (SLE1)
- Source Type
- River
- Treatment Works
- Croydon East Treatment Works
- Last Tested
- 2025-12-31
- Data Source
- Thames Water
Frequently Asked Questions
Is the water hard in South Croydon?▾
Yes, South Croydon has hard water at 303 mg/l CaCO₃. This is classified as "Very Hard" on the standard scale. You may notice limescale buildup in kettles and on taps.
Is South Croydon tap water safe to drink?▾
Yes, tap water in South Croydon 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 South Croydon?▾
The water hardness in South Croydon is 303 mg/l CaCO₃, which is classified as "Very Hard". This is above the UK national average of 170 mg/l.
Who supplies water to South Croydon?▾
Water in South Croydon is supplied by Thames Water, which serves the London and Thames Valley region. The water comes from river sources and is treated at Croydon East Treatment Works.