The Himalayas are filled with streams and rivers. This is the main source of drinking water for the trek.
Our kitchen staff use the same water for cooking purposes as well.
The water is clean and is perfectly healthy to consume. In fact it is much better than the chlorinated water that you get in your cities.
We do understand that you might have concerns with the water and want to be extra careful.
Here is what you can do.
You can use chlorine tablets or water purification tablets in your bottle. You can find these tabs on Amazon. Try searching for water purification tablets.
You can also go for a slightly more expensive but more permanent option. You can buy the life-straw bottle which ensures clean water. 
