Around the world today children miss a total of 443 million days of school every year as a result of water related illnesses. In other words, because of a lack of clean water to drink. I have written posts on this topic before, for example 'Water'.
In the 'Count your Blessings' Lent calendar today Christian Aid suggests giving 5p for every clean glass of water you have drunk today. Including water in tea and coffee I will probably drink at least 6, so that's 30p for Christian Aid.