Water Hardness and Quality in South Ruislip
Supplied by Thames Water · North Downs (SLE19)
South Ruislip has hard water with quality that meets all UK drinking water standards.
Check a specific postcode in South Ruislip
Water Quality Scorecard
Total Hardness
Guideline: 150+ mg/l is considered hard
288mg/l CaCO₃
UK Average: 197.72 mg/l CaCO₃Well Above 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
0.3mg/l
UK Average: 0.45 mg/lBelow Average
LowAverageHigh
Nitrate
UK Standard: max 50 mg/l
25mg/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
0.12mg/l
UK Average: 0.19 mg/lAverage
LowAverageHigh
Water Hardness in South Ruislip
Hardness is the most searched water quality metric. It affects limescale buildup in kettles, boilers, and pipes.
288mg/l CaCO₃Hard
Soft
Mod. Soft
Slightly Hard
Mod. Hard
Hard
Very Hard
South Ruislip has hard water at 288 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
- North Downs (SLE19)
- Source Type
- River
- Treatment Works
- North Downs Treatment Works
- Last Tested
- 2025-12-31
- Data Source
- Thames Water
Frequently Asked Questions
Is the water hard in South Ruislip?▾
Yes, South Ruislip has hard water at 288 mg/l CaCO₃. This is classified as "Hard" on the standard scale. You may notice limescale buildup in kettles and on taps.
Is South Ruislip tap water safe to drink?▾
Yes, tap water in South Ruislip 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 Ruislip?▾
The water hardness in South Ruislip is 288 mg/l CaCO₃, which is classified as "Hard". This is above the UK national average of 170 mg/l.
Who supplies water to South Ruislip?▾
Water in South Ruislip is supplied by Thames Water, which serves the London and Thames Valley region. The water comes from river sources and is treated at North Downs Treatment Works.