In everyday life, we consume water to fulfill the needs of our body. The water we consume comes mostly from water inside soil layer, or we usually know as groundwater. The majority of people think that the quality of groundwater must be good, because the water is protected inside the soil and has been filtered rocks of the earth’s layers. But the fact is not all groundwater has good quality There are several sources of groundwater that are polluted. What exactly is meant by groundwater pollution?
Definition and Characteristics of Groundwater Pollution
Groundwater pollution is a condition where the ground as a gathering place for water is contaminated by pollutants that makes the water inside is also polluted. Types of groundwater pollutants may vary in appearance, some are solid, liquid or gas. These pollutants cause several changes in groundwater like physical, chemical and biological changes. Changes in water properties can be used as indicators of groundwater pollution which include:
- Physical changes – Changes in water that we can see and feel directly using the five senses, such as changes in the level of water clarity, changes in groundwater temperature, and changes in the color & taste of groundwater.
- Chemical changes – Changes in pH (acidity) and the composition of chemicals contained in groundwater.
- Biological changes – The emergence of harmful bacterias in groundwater.
Causes of Groundwater Pollution
As previously described, groundwater pollution is caused by pollutants. But what about the real examples of pollutants that contaminate groundwater? Following are descriptions about the examples of pollutants that cause groundwater pollution.
- Inorganic waste
The first cause of groundwater pollution is inorganic waste. The inorganic waste can be in the form of plastics, cans and styrofoam waste that has accumulated on the ground or buried in the ground. When rain fall down, rainwater will seep into the ground. The rainwater recipe brings with it pollutants derived from organic waste and ultimately causes ground water pollution.
- Organic trash
Organic waste also can be the cause of groundwater pollution. Logically, organic waste decomposes easily and can turn into natural compost for the soil. But what if organic waste such as vegetables and other rotten foodstuffs are buried near ground water sources and it takes a long time to decompose because of the humid conditions caused by the rain. The organic waste will increasingly rot, give off a bad odor and contain lots of bacteria. The bacteria in organic waste can cause ground water pollution.
- Liquid waste
Toxic liquid waste can be in the form of used water to wash clothes, pesticide residual water, oily liquid or even industrial waste liquid containing toxic chemicals. Industrial waste should be managed properly. If the management is negligent, for example doesn’t cover the storage of liquid waste with a waterproof material, then industrial liquid waste containing toxic substances can seep into the ground. If liquid waste seepage is carried by rainwater then empties into ground water sources, then the toxic content of the liquid waste can be a cause of groundwater pollution which is very dangerous for human health.
- Leachate water
The next cause of groundwater pollution is leachate. Among us there maybe some who have never heard of leachate. Leachate water is one type of water that is in the soil layer with depth of about 2 meters from the ground surface. Why is this type of water dangerous? Leachate is used as open dumping in landfills, so that groundwater sources around the landfill can be polluted by ammonia, nitrites and other substances contained in leachate. Groundwater contaminated with leachate will experience an increase in temperature resulting in an acceleration of chemical reactions in the water. Not only changes in temperature, leachate water also causes changes in the color and smell of ground water.
Impact and Ways of Handling Groundwater Pollution
Groundwater pollution has a negative impact on human life. Among the negative effects are:
- Reduced supply of clean water, because groundwater as a source of clean water has been polluted. If the availability of water is insufficient to meet daily needs such as drinking, bathing, washing and toilet, there will be a shortage of clean water which results in decreasing human productivity.
- Increasing population of harmful bacteria. Phatogenic bacteria will multiply rapidly in polluted water. The high population of phatogen bacteria will also reduce oxygen levels in the water.
- Decreased level of health. Consuming and using contaminated ground water can cause various diseases such as diarrhea, vomiting, dysentery, itching and other diseases. If the ground water consumed turns out to be polluted by metal-containing waste, it has the potential to cause cancer and blood-borne diseases.
The impact of groundwater pollution is very threatening human life. To minimize and avoid these impacts, there are several ways that can be done to tackle groundwater pollution. The following is the explanation.
The first way to handle groundwater pollution is remediation. The activity that needs to be carried out in this remediation system is to restore the surface of the land that has experienced pollution. This restoration is done by cleaning the soil surface from pollutants. Remediation can be divided into 3 types namely in situ remediation and ex situ remediation.
Ex situ remediation is done by digging up contaminated soil and then transport it to another safer place. In that place, contaminated excavated soil is put into a watertight tank then a cleaning agent is added. After being stored for some time, the cleaning agent is removed again from the tank and treated at the wastewater treatment plant. Meanwhile, in situ remediation is easier than ex situ remediation. The activities carried out are only cleaning the soil and bioremediation.
As explained earlier, this bioremediation is included in situ remediation. Soil cleansing with bioremediation techniques is done by adding decomposing microorganisms such as mycorrhizal arbuscular vesicular fungus and decomposing bacteria into the soil. The decomposing microorganisms will break down pollutants into corbon dioxide gas and water so that it is no longer harmful to the soil.