Nitrate in UK Drinking Water

Health Effects

High nitrate levels in drinking water are most concerning for babies under three months old, where the conversion of nitrate to nitrite in the gut can interfere with the blood's ability to carry oxygen — a condition known as methaemoglobinaemia. In adults, some research has suggested a possible link between high nitrate intake and cancer risk, though the evidence is still being assessed.

Where It Comes From

The main source of nitrate in UK drinking water is farming — specifically the use of nitrogen-based fertilisers and the spreading of animal manure on fields. Nitrate leaches through soil into groundwater and rivers, which are often used as drinking water sources. Sewage and urban runoff also contribute, though usually to a lesser degree.

Regulatory Standards

How to Remove Nitrate

• Reverse osmosis

  A membrane filtration process that removes up to 99% of contaminants by forcing water through a semi-permeable membrane under pressure. Highly effective but produces some wastewater.

• Ion exchange

  Replaces unwanted ions (such as nitrate or lead) with harmless ones using resin beads. Effective and widely used in both whole-house and point-of-use systems.

• Distillation

  Water is boiled and the steam condensed, leaving most contaminants behind. Highly effective but slow and energy-intensive — typically used in countertop units.