E. coli contamination of mountain springs used for drinking water and drilled well alternatives

Millions of people in developing communities drink water from springs on bedrock mountain slopes. Previous studies show E. coli causing many sampled springs on populated mountain slopes in southwest China to provide unsafe drinking water (Chitwood 2007a). Such studies are rare, but recently a reconnaissance study was initiated in a watershed in the Dominican Republic where more than 25,000 people, spread out across small communities and one town, rely on mountain springs. E. coli testing shows many of these springs to be unsafe. Water users live downslope and distant from the springs and receive spring water via pipelines. Likely, the E. coli originates from sparse livestock grazing up-slope from springs. Small wells drilled using portable rock coring machines and completed using novel continuous seals attached above the water intake zone are proposed to access safe drinking water drawn from permeable fractures tens of meters below ground, avoiding contamination near surface.