Best method of ensuring clean water in small Pakistan village. (Filtration plant or otherwise)?

Need to serve about 100 people. Best method both financially and the fastest and easiest for the area. Can be either a filtration plant or maybe systems in each home. Town is Kotli Loharan West http://wikimapia.org/1402965/ . The people are in great need of clean water, the ground water in the area is very filthy and unsanitary. I need to know the best way(s) to get the water cleaned, thanks