construction of ferrow cement tanks in schools

My school has been lucky to get help from one of the N.G.O working in this community. Due to free primary education students population has gone up. Most of the students have sneaked  to look for drinking water from the nearest river. The water source is very dirty and unprotected because they share with animals. In the school we have heard cases of absentism due repeated sicknesses. After finding out its due to water borne related cases. But after the construction of two tanks in the school we have enough clean water our children rarely become sick as before.