Risk assessment by bacteriological evaluation of drinking water of Gilgit-Baltistan

In gilgit-baltistan,pakistan glaciers are the main source of water and people use surface water from nallahs (big streams) and springs for both drinking and irrigation purposes. the surface water has many chances of water borne diseases. from out of seven districts the drinking water samples of four districts were bacteriolocically analyzed for fecal coliform contamination. randomly selected 46 villages and their water samples were analyzed at different points by using membrane filtration technique and specific medium (lauryl sulphate broth). it was found that 25 villages use water from the springs and fecal coliform contamination was from 0-500 cfu in 100 ml water at source,from 0 - tntc in the beginning,mid and at the end of the distribution system. twenty one villages use water from the nallahs and fecal coliform contamination was from 4-500 cfu at the source,1-1350 cfu in the beginning of the distribution system,44 - tntc in the middle and 110 - tntc in the end of the distribution system. in most of the springs the bacteriological quality of drinking water was good at source and it becomes contaminated as it becomes in contact with animals. most of the nallahs water was contaminated at their source. copyright 2012 zoological society of pakistan.