The purity of tap water really comes down to two things – the source it originates from and the level of filtration it goes through before it gets to our taps. Some countries have the cleanest tap water because they have lots of natural sources such as lakes, glaciers and rivers that are regularly topped up with fresh rainwater.

Other countries simply invest in the latest technology to make the water they can harvest as filtered as possible. Here are some of the countries that are getting it right.


If you’ve ever been to Switzerland, it probably won’t surprise you that the alpine nation is home to some of the world’s cleanest tap water. Switzerland’s clean tap water results from both good geography and good policy. The country receives plenty of rain, which combined with melt from its glaciers, provides far more water than the population needs. Additionally, Swiss government policy strives to protect its water supply, and has for many decades.

Swiss landscape, Castle Water logo in corner


Canada’s vast geography provides a multitude of freshwater sources, meaning the tap water supply is one of the best in the world. Cities in Canada maintain a rigorous and highly-regulated filtration process for urban tap water, further underscoring its cleanliness and safety.

United Kingdom

British tap water is one of the cleanest in the world for many of the same reasons as Switzerland and Canada’s is. For one thing, the rural northern reaches of England, Scotland and Wales are home to scores of freshwater lakes, or lochs, which are an important source of drinking water for much of the country. Additionally, you may have noticed that the UK is one of the rainiest countries in the world, which has the benefit of regularly replenishing the water supply. The UK also boasts some pretty advanced filtration processes, capable of even making water from the Thames drinkable!

New Zealand

Like Canada and Switzerland, New Zealand is a sparsely populated, mountainous nation with plenty of glaciers that melt into clear, beautiful lakes. The country’s citizens and politicians also recognise the national importance of clean water, and this has led to consistent efforts to keep their drinking water pristine.

Person drinking water. Castle Water logo in corner


The densely-populated country occupies a land area similar to the city of Los Angeles, but has more than 5 million residents. A lack of freshwater sources means Singapore uses a network of reservoirs and state-of-the-art filtration processes to provide its residents with some of the cleanest drinking water in the world.


Germany has a long history of passing laws that protect its natural resources, so it makes sense that Germany is home to some of the world’s cleanest tap water. It also helps that Germany again gets most of its water from natural lakes and glacial snow melt. In order to further keep on top of what Germany’s residents are drinking, the government has a policy of releasing specific data about what the country’s tap water contains.

Scandinavia and Finland

Individually, the nations of Scandinavia all rank very highly when rating clean tap water around the world. If you put them all together, it’s clear that this region of the world is where one can find perhaps the cleanest and safest water flowing from taps. Just for good measure, Finland further filters its naturally clean water multiple times before it reaches the tap.

Water being poured. Castle Water logo in corner

The advantages of good geography and a suitable climate certainly go a long way to producing clean water, but the examples of Singapore, and the UK, show that modern filtration systems can also produce high-quality tap water.

Castle Water Partnership with Save the children

Unfortunately, many countries lack both the natural resources and the infrastructure required to provide clean water to their populations, especially when disaster strikes. Castle Water is delighted to partner with Save the Children to help those most in need during times of war, drought or natural disaster. Our fundraising efforts help to rehabilitate water and sanitation systems in communities and help affected families get back on their feet. Our partnership with Save the Children means that Castle Water and its customers are helping to ensure that children and their families have access to the life-saving essentials they so desperately need, including clean water.

Water droplets on white background

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