Drinking water quality
In the UK our drinking water is of the highest standard, at a record level of quality and among the best in the world. We can turn on our taps with the certainty of a safe, clean and refreshing supply.
UK water suppliers place the highest priority on assuring the quality of water provided to their customers. Strict standards for the quality of the UK public supply are laid down in national regulations derived from the EU Drinking Water Directive. These standards are based on advice from the World Health Organization (WHO) and are regularly reviewed.
Water quality is also closely checked and regulated by independent drinking water inspectorates in England and Wales, Scotland and Northern Ireland, who report each year.
Latest figures for drinking water quality compliance with the strict UK and European standards
- England and Wales 99.96% (reported July 2018)
- Scotland 99.91% (reported August 2018)
- Northern Ireland 99.86% (reported August 2017)
UK, EU and WHO standards
In the UK all drinking water, whether from public supplies or other sources, has to meet standards laid down in the EU Drinking Water Directive (98/83/EC). It is the duty of each EU member state government to translate the requirements of the directive into local laws, which must as a minimum meet the requirements of EU legislation.
UK regulations follow the EU directive, but some aspects are stricter than, or in addition to, those defined by the directive, reflecting the high standards of water supplies in the UK. The Drinking Water Directive is transposed into UK law through primary legislation and regulations that is specific to each of the four devolved administrations:
The law requires that drinking water is wholesome and clean. It sets down maximum acceptable concentrations for a number of potential contaminants. In addition, there is a general clause, which requires:
“Water is free from any micro-organisms and parasites and from any substances which, in numbers or concentrations, constitute a potential danger to human health.”
The EU and UK standards are based on advice from the World Health Organization – through the WHO Guidelines for Drinking Water Quality, which are regularly updated to take account of new knowledge. The EU Drinking Water Directive also requires the European Commission to review the standards at least every five years in order to take account of changes in the WHO guidelines and current knowledge.
As well as water quality standards, the EU directive lays down strict requirements for:
- monitoring and analysis
- public reporting of data
- use of treatment chemicals and materials in contact with water
- action that must be taken if a standard is exceeded.
The directive takes a traditional regulatory approach, based largely on requirements to test many water samples for potential chemical and biological contaminants and check that these are within limits set in EU standards. This approach is supported by a range of measures that are routinely used by the water industry to assure drinking water quality.