Groundwater contamination is the adulteration of water because of the increase in the concentration of certain pollutants. The major pollutants contributing to contamination are Arsenic, fluoride, Iron, uranium , nitrate etc.
Causes of groundwater contamination are:
- Natural: Groundwater naturally contains high amount of pollutant due to geological formation. For example occurrence of fluoride is related to the abundance and solubility of fluoride containing mineral such as fluorite.
- Agriculture: Intensive use of agriculture has lead to the seepage of nitrate into groundwater. Exploitation by excessive use of irrigation is another reason as it lead to decline un ground water table.
- Industrial waste: Industrial waste are discharged without effluent treatment. They seep through the soil and pollute the groundwater.
- Indiscriminate extraction of groundwater for irrigation purpose has led to the salinity problem. Excessive discharge of water from coastal region has led to the sea water intrusion hence it has also lead to increase salinity.