Wells have been traditionally sunk by hand digging as water monitoring system pdf the case in rural developing areas. These wells are inexpensive and low-tech as they use mostly manual labour and the structure can be lined with brick or stone as the excavation proceeds. Driven wells can be created in unconsolidated material with a well hole structure, which consists of a hardened drive point and a screen of perforated pipe, after which a pump is installed to collect the water. Drilled wells are usually cased with a factory-made pipe composed of steel or plastic.
Drilled wells can access water at much greater depths than dug wells. A collector well can be constructed adjacent to a freshwater lake or stream with water percolating through the intervening material. Water may be pumped or hand drawn. Impurities from the surface can easily reach shallow sources and contamination of the supply by pathogens or chemical contaminants needs to be avoided. Well water typically contains more minerals in solution than surface water and may require treatment before being potable. Some of the earliest evidence of water wells are located in China. The neolithic Chinese discovered and made extensive use of deep drilled groundwater for drinking.
Chinese maintained their wells and protected their sources of water. Archaeological evidence and old Chinese documents reveal that the prehistoric and ancient Chinese had the aptitude and skills for digging deep water wells for drinking water as early as 6000 to 7000 years ago. The well was cased by four rows of logs with a square frame attached to them at the top of the well. 60 additional tile wells southwest of Beijing are also believed to have been built around 600 BC for drinking and irrigation. Some of the world’s oldest known wells, located in Cyprus, date to 7000-8500 BC.
Two wells from the Neolithic period, around 6500 BC, have been discovered in Israel. One is in Atlit, on the northern coast of Israel, and the other is the Jezreel Valley. Leather bucket used for the water well. The excavation is braced horizontally to avoid landslide or erosion endangering the people digging.
They may be built with a high degree of community participation, or by local entrepreneurs who specialize in hand-dug wells. They have low operational and maintenance costs, in part because water can be extracted by hand bailing, without a pump. The water is often coming from an aquifer or groundwater, and can be easily deepened, which may be necessary if the ground water level drops, by telescoping the lining further down into the aquifer. The yield of existing hand dug wells may be improved by deepening or introducing vertical tunnels or perforated pipes.