Groundwater accounts for about 20% of the world's freshwater supply, which is quite large a quantity. This statistic makes groundwater a very important resource of water. Moreover, groundwater normally is not easily susceptible to natural pollutants and contamination as compared to surface water. Therefore, it amounts to as a buffer storage in case of shortage of surface water in times of droughts.
Groundwater is found beneath the ground. But how does water get accumulated there? Water in the form of rain, snow and hail, seeps into the ground, passes through the particles of soil, sand, gravel or rocks, and reaches deep down the surface of the ground, where it is accumulated. The zone where under groundwater is stored is called the saturated zone. Since it is stored hundreds of feet below the ground surface, it is normally clean, but it too can be polluted or contaminated. In fact, a lot of aquifers (a layer of porous substrate that holds water, which can be pumped with the help of a well) are seen getting contaminated. This contaminated water enters the food chain and can be a cause to many life-threatening diseases and problems. Many governments are seen taking serious steps to curb this problem. Let's get to know more on exactly what causes groundwater pollution.
The natural soil or rock conditions contain certain impurities. This leads to pollution of the groundwater. When water passes through the rocks, soil, stones, etc., it might pick up a range of magnesium, arsenic, boron, calcium, chloride and selenium compounds, all of these cause the groundwater to contaminate. Sometimes, the pipelines used to pump water from the aquifers are corrosive, and have defective welds. There have been instances of poor installation and maintenance of the same, which leads to groundwater pollution.
Pesticides, fertilizers and herbicides used for agriculture contribute to the problem of groundwater pollution. They have harmful chemical compounds and elements that contaminate the groundwater. Harmful compounds of nitrates and phosphates present in the fertilizers and pesticides sink deep into the soil, contaminate the water. This water enters the food chain, thus causing a lot of diseases and harmful effects.
Underground Shortage Tanks
Underground shortage tanks, sometimes due to corrosion, poor installation or maintenance and leakage, may release oil, chemicals, gasoline or other type of liquids, thus contaminating the water below the ground surface. This leads to some serious contamination. There have been around 400,000 leaking underground storage tanks in the United States in 2001, as per the reports of the U.S. Environmental Protection Agency.
Landfills is the area where garbage is taken to be buried. A huge deep depression is dug to bury the waste. But this muddle is supposed to have a protective layer so that it does not interfere with the saturated zone. However, sometimes, there is no layer, or even a crack facilitates the mixing of garbage with the water in the aquifer, thus, polluting the groundwater.
Once you diagnose the causes of groundwater pollution, it is important to take grave and serious steps to curb the same. Because, once the groundwater is polluted, to pump it out, purify it and re pump the purified water into the saturated zone is a tough, tedious and an expensive job. Sometimes it seems almost impossible to remove pollutants.
The technologies that include purifying the groundwater pollutants go as follows: advanced oxidation, air stripping and granular activated carbon. The mechanism on which they work is, pumping out the contaminated water, then heating it to evaporate the pollutants and then re-injecting the cleaned water. This process works out costly and sometimes is unsuccessful.
We may not be able to eliminate groundwater pollution from scratch, but we can definitely do our bit to protect this source of water. Moreover, governments are seen taken serious steps to fight the problem of pollution, so let's stand by it, educate ourselves and fight this evil (groundwater pollution) in unity.