Assessment of groundwater used for domestic uses is important for its quality. Before any use, it is important for proper treatment regardless the treatment technology. Groundwater as a source believed to be safe, it might be polluted in different points from source to consumer points. Natural formation of the soil and other factors may influence the entrance of chemicals and other pollutants. Depth of water sources i.e boreholes and shallow well is a major factor to consider when choosing the water sources. Это и многое другое вы найдете в книге Groundwater Quality and Sanitation in Relation to Public Health (Isabela Thomas)