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
Health
score
69
Taste
score
51
Skin
score
48
Hair
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%