For trekking Nepal is the most popular country in the world Because of its snow Himalayan range. Every person has curiosity to know how about drinking water in the trekking period. Tap water in trek also very well for drinking for Nepali people because it comes from Snow Mountain and glaciers. But for tourist not sure they can direct drink or not because they have no habit. They can purify this water or use pills or chlorine drops and can drink. Some part of trekking you can buy mineral water but some trekking routes you cannot buy mineral water because of plastic pollution control. That part you can find some safe drinking water station from Annapurna Conservation Area Project. Or you can buy boiled filter water from the tea houses. Many of the Everest tea houses you can find mineral water bottle. But it is quite expensive. Better you can bring water cleaning tablet by yourself. But never drink city water from tap. it is very poor. you must buy mineral water for drinking in the city like Kathmandu and Pokhara.