Water Hardness and Quality in Farnham
Supplied by Thames Water · Guildford District West (G7)
Farnham has moderately hard water with quality that meets all UK drinking water standards.
Check a specific postcode in Farnham
Water Quality Scorecard
Total Hardness
Guideline: 150+ mg/l is considered hard
197mg/l CaCO₃
UK Average: 197.72 mg/l CaCO₃Average
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
0.51mg/l
UK Average: 0.45 mg/lAbove Average
LowAverageHigh
Nitrate
UK Standard: max 50 mg/l
26mg/l
UK Average: 16.9 mg/lWell Above Average
LowAverageHigh
Lead
UK Standard: max 10 µg/l
1.8µg/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 Farnham
Hardness is the most searched water quality metric. It affects limescale buildup in kettles, boilers, and pipes.
197mg/l CaCO₃Moderately Hard
Soft
Mod. Soft
Slightly Hard
Mod. Hard
Hard
Very Hard
Farnham has moderately hard water. You may notice some limescale buildup in your kettle and on taps over time. A regular descaling routine should be sufficient for most households.
Water Source Information
- Water Company
- Thames Water
- Supply Zone
- Guildford District West (G7)
- Source Type
- Groundwater
- Treatment Works
- Guildford District West Treatment Works
- Last Tested
- 2025-12-31
- Data Source
- Thames Water
Frequently Asked Questions
Is the water hard in Farnham?▾
Farnham has moderately hard water at 197 mg/l CaCO₃. Some limescale may occur but it is manageable with regular descaling.
Is Farnham tap water safe to drink?▾
Yes, tap water in Farnham 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 Farnham?▾
The water hardness in Farnham is 197 mg/l CaCO₃, which is classified as "Moderately Hard". This is above the UK national average of 170 mg/l.
Who supplies water to Farnham?▾
Water in Farnham is supplied by Thames Water, which serves the London and Thames Valley region. The water comes from underground aquifers and is treated at Guildford District West Treatment Works.