REASONS BEHIND GROUNDWATER POLLUTION
There are several reasons behind Groundwater Pollution that can be categorized as
natural, agricultural, industrial, municipal and indiscriminate extraction of ground water.
Groundwater naturally contains impurities due to nature of geological formations.
Some substances found naturally in rocks or soils, such as iron, manganese, arsenic, chlorides, fluorides, sulfates, or radionuclides, can become dissolved in ground water.
In India, uranium concentration is also related primarily to natural causes.
Other naturally occurring substances, such as decaying organic matter, can move in ground water as particles. Whether any of these substances appears in ground water depends on local condition.
Intensive use of chemical fertilizers leads to leaching of the residual nitrate causing high nitrate concentrations in groundwater
Excessive and improper irrigation practices.
Excessive use of these chemicals can lead to contamination of groundwater. Chemicals such as pesticides are known to remain in the ground for years and when diluted with the rainwater they seep deeper into the groundwater.
Industrial effluents seeps through the soil and pollutes the groundwater.
Toxic industrial waste releases traces of heavy metals such as lead, cadmium, zinc and mercury.
Brine disposal from the petroleum industry, mine wastes, deep-well disposal of liquid wastes
Leaky underground gas tanks
Pollution by landfills, septic tanks
Indiscriminate disposal of human and animal waste on land; faulty onsite sanitation structures
Leaky sewer lines
INDISCRIMINATE EXTRACTION OF GROUNDWATER:
Indiscriminate extraction of groundwater for irrigation purposes has led to inland salinity problem in parts of Punjab, Haryana
Excessive withdrawal of groundwater from coastal aquifers has led to induced pollution in the form of seawater intrusion. For example: In Kachchh, Gujarat
Uranium contamination has aggravated by groundwater-table decline. Decline in groundwater table induces oxidation conditions. As a result, uranium enrichment in shallow groundwater is enhanced.