5 Countries With the Cleanest Drinking Water

Clean, safe drinking water is one of the foundations of public health. But defining the countries with the “cleanest” water requires a measurable standard rather than judging taste or appearance. The 2024 Environmental Performance Index (EPI), produced by Yale and Columbia researchers, evaluates the health burden associated with unsafe drinking water and sanitation.

On the EPI’s broader Sanitation & Drinking Water category, Finland, Germany, Switzerland and the United Kingdom share the highest possible score of 100.0. Because four countries are tied for first, Luxembourg is included here as the next-highest scoring country, with 99.8. The ranking therefore reflects protection from health risks linked to drinking water and sanitation—not a laboratory contest for the purest-tasting tap water.

1. Finland — EPI score: 100.0

Finland shares the top global position. Its strong result reflects an extremely low health burden from unsafe drinking water and sanitation. Abundant freshwater resources, extensive treatment infrastructure, monitoring and strong public-health systems help support reliable drinking-water quality. In the EPI’s specific unsafe-drinking-water indicator, Finland also receives a perfect 100.0 score.

2. Germany — EPI score: 100.0

Germany also receives the maximum score in the combined category and in the unsafe-drinking-water indicator. Drinking water is subject to extensive quality controls, and utilities rely on protected groundwater, surface-water sources and treatment systems depending on the region. The EPI result indicates that health losses attributable to unsafe drinking water are among the lowest measured globally.

3. Switzerland — EPI score: 100.0

Switzerland is renowned for its lakes, rivers, Alpine catchments and groundwater, but natural abundance alone does not guarantee safe tap water. Treatment, source protection and regulatory oversight are critical. Switzerland earns 100.0 in both the EPI Sanitation & Drinking Water category and its unsafe-drinking-water indicator, placing it among the strongest performers worldwide.

4. United Kingdom — EPI score: 100.0

The United Kingdom shares first place in the combined EPI category and also scores 100.0 for unsafe drinking water. Public supplies undergo treatment and routine testing, with regulatory systems designed to control microbial, chemical and other risks. The EPI score reflects a very low estimated disease burden attributable to unsafe drinking water.

5. Luxembourg — EPI score: 99.8

Luxembourg follows immediately behind the four countries tied at the top, scoring 99.8 in the combined Sanitation & Drinking Water category. It also receives 99.8 on the EPI unsafe-drinking-water measure. Its small population, regulated public supply systems and high level of water and sanitation infrastructure contribute to its strong performance.

What Does “Cleanest Drinking Water” Actually Mean?

The EPI does not rank water according to mineral content, taste, clarity or the pristine appearance of rivers and lakes. Its unsafe-drinking-water indicator uses age-standardized disability-adjusted life years (DALYs) lost because of exposure to unsafe drinking water. A score of 100 represents countries with among the world’s lowest estimated health burdens from unsafe drinking water.

Why Safe Tap Water Depends on More Than Natural Sources

Countries with excellent drinking water generally combine protected water sources with modern treatment, distribution networks, continuous monitoring, sanitation infrastructure and enforceable standards. Even naturally clean groundwater or mountain water can become unsafe through microbial contamination, agricultural runoff, ageing pipes or other pollutants if it is not properly protected and managed.

Other Countries With Exceptional Results

Several other countries perform extremely well. Norway scores 99.8 in the combined Sanitation & Drinking Water category, followed by Australia at 99.5 and Singapore at 99.2. On the drinking-water-only indicator, Greece, Ireland, Italy and the United States also receive 100.0, illustrating why rankings can differ depending on whether sanitation is included.

Can Travellers Drink Tap Water Everywhere in These Countries?

National rankings describe overall performance and should not be interpreted as a guarantee for every individual building, private well or temporary local situation. Local advisories can still occur because of maintenance, flooding, contamination incidents or problems within a building’s plumbing. Travellers and residents should follow local authority guidance when an advisory is issued.

The Bottom Line

Using the 2024 Environmental Performance Index’s combined Sanitation & Drinking Water measure, Finland, Germany, Switzerland and the United Kingdom share the global lead with perfect scores, while Luxembourg follows at 99.8. The results show that world-class drinking-water safety depends not only on clean natural resources but also on effective treatment, sanitation, monitoring and public-health protection.