World Health Organisation (WHO )Guidelines for Drinking Water Quality – 4th Edition General Considerations: “Access to safe drinking water is essential to health, a basic human right. It has been shown that investments in water supply & sanitation can yield a net economic benefit, as the reductions in adverse health effect & health-care costs outweigh the costs of undertaking the interventions. This is true for investments ranging from major water supply infrastructure through to water treatment in the home. Experience has also shown that interventions in improving access to safe water, favour the poor in particular, whether in rural or urban areas, & can be an effective part of poverty alleviation strategies.”