Groundwater sampling is conducted by taking a sample of water from a well. Groundwater sampling is done to assess the level of pollution of the groundwater table. It is one component of hydrology, the study of the quality and distribution of water throughout the world.
Water wells used for groundwater sampling usually contain a surface seal. A surface seal consists of a large hole that is drilled to a certain and predetermined depth. A smaller hole for the well is then created. This smaller hole is called the well. The well is cased from the surface downward.
The space between the well and the larger hole typically is filled in with concrete or some similar material. The bottom of the well is usually fitted with some type of filter device that filters out unwanted material. Water is then left to flow in. Groundwater sampling involves taking the filtered water from the well to test it for pollutants and contaminants.
There are two classes of drilled wells. The first are shallow or unconfined wells, and the second are deep or confined wells. The first are drilled to a depth in the uppermost saturated aquifer location. The latter are drilled through the impermeable stratum down to the aquifers.
Groundwater sampling is necessary to get an accurate idea of the pollution in groundwater. Water pollution is fast contaminating lakes, rivers, oceans and groundwater sources. It affects plants and organisms alike, yet the biggest threat is to human beings.
Surface water and groundwater are different. The connection between groundwater and water found on the surface of the earth is complex. Often groundwater contamination is not as easily classified as pollution because the causes or sources of groundwater contamination are different from those of surface water contamination.
Groundwater contamination may occur as a result of run-off. A chemical contaminant laid on soil many miles away from surface water will not affect the surface water, but it most likely will affect the groundwater below. Therefore the search for groundwater contamination is often done by looking at either the characteristics of the soil and/or by hydrology.
Hydrology is the study of the quality and distribution of water throughout the world. It addresses hydrological cycles and water resources. There are many disciplines encompassing Hydrology, one of which is Hydrogeology. Hydrogeology studies groundwater in the soil, rocks and in the earth’s crust or aquifers. In order to ascertain these levels of pollution, groundwater sampling must be conducted.