Water that seeps via soil and rocks and is held under the surface is groundwater. Aquifers are the rocks in which groundwater is kept. Gravel, sand, sandstone, and limestone are common components of aquifers. Water can pass through these rocks due to their huge interconnected gaps, making them permeable. The saturated zone is the area where water fills the aquifer. The water table is the depth below the surface where groundwater can be found. The water table can be as shallow as a foot or as deep as a hundred metres below the surface. Heavy rains can cause the water table to rise, while continual groundwater extraction can lead it to decrease.
What is underground water pollution?
When chemicals are released into the earth and find their way into groundwater, this is known as groundwater pollution. This form of water pollution can also occur naturally due to a minor and undesired element, contaminant, or impurity in groundwater. It is referred to as contamination rather than pollution. On-site sanitation systems, effluent from wastewater treatment plants, landfill leachate, petrol filling stations, leaking sewers, hydraulic fracturing, and overuse of fertilisers in agriculture can all pollute groundwater. Natural pollutants such as arsenic and Fluoride can also pollute the environment. Using contaminated groundwater poses a health risk to the population, as it can lead to poisoning or the spread of waterborne disease.
The pollutant sometimes makes contaminated plumes by an aquifer. The contaminant is dispersed over a larger area due to the movement of water & dispersion within the aquifer. Its expanding boundary, known as a plume edge, can collide with surface water and groundwater wells, such as springs and seeps, contaminating human and wildlife water supplies. A hydrological transport model or a groundwater model can be used to examine the plume’s movement, known as the plume front. The nature of the contaminants and soil properties and site hydrogeology, hydrology, and geology may be examined in the context of groundwater pollution. Different mechanisms, such as adsorption, diffusion, precipitation, and degradation, impact the movement of contaminants in groundwater.
Groundwater pollution causes
- Contamination occurs when naturally existing soil and rocks chemicals dissolve in water. Iron, radionuclides, Sulfates, manganese, fluorides, arsenic, and chlorides are among these compounds. Others, such as potting soil components, may seep into underground water and move as particles. As per the WHO records, Fluoride and arsenic are the most common contaminants. The Groundwater Assessment Platform can be used to investigate the natural causes of pollution, and GAP uses geological, environmental, and topographical data to calculate pollution levels.
- Photographic chemicals, cooking oil, motor oil, pharmaceuticals, paint thinners, paints, garden chemicals, and swimming pool chemicals should not be disposed of in septic tanks or directly into the ecosystem since they can contaminate the environment. A licenced hazardous waste handler should be contacted to dispose of these compounds.
- To improve crop output, millions of tonnes of agricultural chemicals such as fertilisers and insecticides are utilised worldwide. These chemicals are also used by other places, such as golf courses. Excessive usage of these substances can lead to groundwater contamination. Pesticides, for example, have been known to stay in the ground for years and, when diluted by rains, seep further into groundwater.
- Abandoned wells are another source of ground pollution, as they can act as a conduit for toxins to reach aquifers. Poorly designed wells, which may be missing suitable casing and covers, can lead to groundwater contamination if pollutants find their way into them. Mining activities are another source of contamination because soluble minerals can be leached from the sites into the groundwater through precipitation.
Effects of groundwater pollution
The various effects of the groundwater pollutants are:-
Contaminated groundwater is hazardous to one’s health. Human excrement may contaminate water sources when septic tanks are not installed correctly. Hepatitis-causing germs could be present in the excrement, causing irreparable liver damage. It can also induce dysentery, which causes severe diarrhoea, dehydration, and mortality in certain cases. Poisoning from excessive pesticides and fertilisers, as well as natural chemicals, might cause additional health concerns. The chemicals contaminate water sources by leaching into them, and drinking water from such a source could harm your health.
Contamination of groundwater supplies makes the area unfit for plants, humans, and animal life to thrive. The area’s population decreases, and the value of the land decreases. Another effect is that industries that rely on groundwater for production suffer from reduced stability. As a result, industries in the impacted areas may rely on water from other regions, which could be costly. Furthermore, they may be compelled to close due to low water quality.
Groundwater pollution can lead to a harmful impact on the ecosystem. One such change is the loss of specific nutrients necessary for the ecosystem’s self-sustenance. Additionally, when contaminants interact with water bodies, the marine ecosystem may be altered. As a result of too many toxins in the water bodies, aquatic species such as fish may die off quickly. Animals and plants that drink contaminated water may be harmed as well. Toxic compounds build up in aquifers over time, and once the contamination spreads, the groundwater may become unfit for direct human consumption. The consequences are severe, particularly for those who rely on groundwater during droughts.
We have read about the various causes, consequences, and effects of underground water pollution in the above topic. The release of contaminants into the earth to underground water storage known as aquifers causes groundwater pollution. When contaminants are discharged into the environment, they contaminate groundwater. It is a sort of water pollution that is mostly produced by the purposeful or unintentional release of pollutants from anthropogenic or natural sources.