The water available in Nepal is regarded to be contaminated, not only to the tourists but the local people as well. Even your hotel tap water is not safe so always use mineral water for brushing your teeth. Also, ask for no ice in your drinks, because you can’t be sure it was made from boiled water. When eating on your own at a restaurant in Kathmandu, you’re probably safe ordering thoroughly cooked items (served to you while they’re still hot), but avoid raw vegetables, salads, and shellfish to be extra cautious. You can eat fresh fruit that you peel yourself. The trip leader will provide you with more detailed guidelines. 
 
In the trek, the food served in our camps is prepared hygienically by a trained, experienced camp staff. We provide properly boiled water at every, meal. To be extra cautious you can also carry iodine tablets with you.