Tap water in London
Water report for SW1A 1AA
Updated 09/04/2026
26 contaminants identified in your water.
56/100Fair
6above limit
10near limit
10within limit
Expert Summary
London's tap water meets regulatory standards and is safe to drink, but this profile shows a few parameters elevated above more conservative health-based guidelines — most notably lead and arsenic — which may add to long-term organ load and oxidative stress over time. Taste is typically acceptable, though hardness-driven limescale can leave water feeling "chalkier" and contribute to dry skin and rougher hair texture after showering.
Score breakdown
54
score
69
score
51
score
48
score
Your water composition
Chlorine
The disinfectant that gives tap water its "pool" smell
2xabove limit
Cancer risk
Chlorine taste
Skin irritation
Hair loss
Lead
A toxic metal from old pipes and solder joints
1.5xabove limit
Cancer risk
Nervous system
Chalky taste
Nitrate
From farm fertilisers washing into rivers and groundwater
0.8xnear limit
Infant risk
Bitter aftertaste
Trihalomethanes
Created when chlorine reacts with organic matter
1.3xabove limit
Cancer risk
Liver risk
Chemical taste
Fluoride
A mineral added to some supplies for teeth health
0.7xnear limit
Thyroid risk
Bone damage
Iron
Causes brown stains. From corroding cast-iron water mains
0.3xwithin limit
Rusty smell
Metallic taste
Arsenic
A toxic element dissolved from underground rock formations
1.2xabove limit
Cancer risk
Skin irritation
Copper
Dissolves from copper pipes, especially after overnight stagnation
0.6xnear limit
Liver risk
Metallic taste
Manganese
Causes black stains and particles in peaty water areas
0.2xwithin limit
Metallic smell
Hair loss
Aluminium
Added at treatment to filter particles. Residues pass to your tap
0.9xnear limit
Nervous system
Earthy taste
Sodium
Table salt entering water from road salt runoff or seawater
0.4xwithin limit
Salty taste
0%