What can i do to ensure the cleanliness of my drinking water when i am traveling?

Water safety: Good question! limit yourself to bottled water, ask for good local brand, sometimes drinking water warm versus cold can kill lots of parasites. You can boil your water, let the sediment sink, decant water into new container and then drink. Avoid asking for ice in your drinks as many times made from unsterile water. Careful also with salads and fruits. If camping you may use portable tablets. Best!