Water Hardness and Quality in Horsham
Supplied by Thames Water · Cranleigh (G4)
Horsham has moderately soft water with quality that meets all UK drinking water standards.
Check a specific postcode in Horsham
Water Quality Scorecard
Total Hardness
Guideline: 150+ mg/l is considered hard
76mg/l CaCO₃
UK Average: 197.72 mg/l CaCO₃Well Below Average
LowAverageHigh
pH Level
UK Standard: 6.5 – 9.5
7.6pH units
UK Average: 7.43 pH unitsWell Above Average
LowAverageHigh
Free Chlorine
Guideline: below 1 mg/l
0.6mg/l
UK Average: 0.45 mg/lWell Above 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
0.09mg/l
UK Average: 0.19 mg/lBelow Average
LowAverageHigh
Water Hardness in Horsham
Hardness is the most searched water quality metric. It affects limescale buildup in kettles, boilers, and pipes.
76mg/l CaCO₃Moderately Soft
Soft
Mod. Soft
Slightly Hard
Mod. Hard
Hard
Very Hard
Horsham has soft water. This means less limescale buildup in your appliances, less soap needed for cleaning, and generally fewer issues with mineral deposits. You are unlikely to need a water softener.
Water Source Information
- Water Company
- Thames Water
- Supply Zone
- Cranleigh (G4)
- Source Type
- Groundwater
- Treatment Works
- Cranleigh Treatment Works
- Last Tested
- 2025-12-31
- Data Source
- Thames Water
Frequently Asked Questions
Is the water hard in Horsham?▾
No, Horsham has soft water at just 76 mg/l CaCO₃. You are unlikely to experience significant limescale issues.
Is Horsham tap water safe to drink?▾
Yes, tap water in Horsham 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 Horsham?▾
The water hardness in Horsham is 76 mg/l CaCO₃, which is classified as "Moderately Soft". This is below the UK national average of 170 mg/l.
Who supplies water to Horsham?▾
Water in Horsham is supplied by Thames Water, which serves the London and Thames Valley region. The water comes from underground aquifers and is treated at Cranleigh Treatment Works.