Any good company or guide will supply filtered water; however, bottled water can be purchased at most tea houses and shops along the route. Because of the altitude it is recommended you drink in the region of 3-4 liters per day, although this can include, tea and soup. During Annapurna Sanctuary trek (ABC), you don’t find a bottle mineral water. Instead, you have to refill safe drinking water which is available in each and every teahouse around Annapurna region. Safe drinking water is 100% safe to drink. Safe Drinking water is maintained by a local committee which mainly looks after the cleanliness of the water. It will be better to have one spare of an empty bottle while refilling the water. You can also bring water purifying tablets for safe drinking water which helps to save the cost.
But if are Trekking in Everest region then in some places you will found the Bottle mineral water but it is a little Expensive than City area. For example, at the starting point of the Everest Base
Camp Trek – Lukla (2,860 m), a liter of water costs Rs 60, but at GorakShep (5,200 m) the price of water is already Rs 300. To save money, many trekkers take a thermos with them and ask trekking lodge landlords for hot water. It’s true that this will have been taken from some local stream and boiled.If you want to save your money, there is some option. You have to carry purify Tablets from Kathmandu for the water. If you carry Tablets then you should not have to pay any extra money for purifying the water while trekking period.