Over 70% of Earth's surface is covered in water but less than 1% is available freshwater for humans to utilize. The ongoing weathering and erosion of the land throughout history has led to the ocean being salty, which is usually about 35 parts per thousand. In comparison, human blood is around 9 parts per thousand, which is a reason why we cannot handle drinking saltwater. Our kidneys cannot efficiently filter out the salts before we would become severely dehydrated. Some animals have super efficient kidneys and can, though, like whales, dolphins, and seals. The country of Aruba gets its drinking water through desalination and is said to have the cleanest drinking water in the world. Over 70% of Earth's surface is covered in water but less than 1% is available freshwater for humans to utilize. The ongoing weathering and erosion of the land throughout history has led to the ocean being salty, which is usually about 35 parts per thousand. In comparison, human blood is around 9 parts per thousand, which is a reason why we cannot handle drinking saltwater. Our kidneys cannot efficiently filter out the salts before we would become severely dehydrated. Some animals have super efficient kidneys and can, though, like whales, dolphins, and seals. The country of Aruba gets its drinking water through desalination and is said to have the cleanest drinking water in the world.