Nazmunnaher Nipa :
Water is a very important element of the environment, specially groundwater. Groundwater is the water resource which is stored under the surface. About 30% of the world’s fresh water comes from groundwater. However, about 97% of the recoverable water comes from groundwater.
In Bangladesh, most of the villagers depend on ground water for drinking water. In urban areas, water supply is mainly dependent on groundwater. In the capital of Bangladesh, more than 87% of the total water supply comes from underground water. Groundwater is widely used for irrigation. According to the estimates of 1995, 72% of the total irrigation water is extracted from the ground.
According to a World Health Organization report, in the developing countries, 2.5 million people die from water-borne diseases every year. It is also said that there is a shortage of 10 million liters of pure water every day in the country. Every day in the capital of Bangladesh, 220 to 300 million liters of water is needed.
At present, about 30 million people are suffering from water crisis across the country every year. As the demand of drinking water in the country every day, it is not possible to completely meet that demand from ground water. Groundwater levels are going down every year due to unplanned water extract. As the water level goes down, underground water are coming into the tube well with harmful heavy metals and contaminants.
As a result of drinking this water people are suffering from various diseases. Generally, water is extracted through shallow tube wells in our village. But at present, due to extract extra water, it is not available at a time of the year, especially during the dry season. With this added new groundwater pollution because the surface contamination goes down into the soil and mixes with water which rises again through the tube well. That water enters the human body, reduces immunity and helps to create new diseases.
Now-a-days, arsenic is causing broad contamination in groundwater. This is one of the biggest problems to the development of groundwater. Prior to the discovery of ionic contamination, people in the village were largely dependent on groundwater. At present, this amount has decreased substantially. Currently, arsenic pollution in the country is in terrible shape. Arsenic is stored at a special level of the soil and is lifted through the tap water.
The use of chemical fertilizers and pesticides in agricultural land is one of the major causes of arsenic pollution. The arsenopyrite, which contains a special layer of soil, is mixed with water due to the excess water extraction. Arsenic pollution is being created which is taking terrible shape over time.
Moreover, salinity is increasing day by day in the ground water. Coastal areas are more prone to salinity. Experts say the saline areas in the southern part of the country are increasing gradually. It has also spread to western areas. As a result, crop production is gradually decreasing. Besides, the water is also inaccessible due to its salinity in the coastal areas of the country.
When the groundwater surface falls below 6 meters, water does not rise in the tube well. Then different technologies have to take. Continued degradation of groundwater also increases the cost of digging wells. Another damaging aspect of groundwater depletion is land debris. The situation is suspected in Dhaka City.
Various industries are growing in the country. Construction of various vehicles in petrochemical industry, polyethylene and plastics industry, energy industry, mineral oil refining industry, small and medium electrical and engineering industries in large quantities of pollutants such as ammonium chloride, cyanide and various metals such as zinc, mercury, lead water.
According to the IEDCR and CDC program sources of the Health Department, water is increasing the risk of natural imbalance. Due to the rapid population growth and urbanization, residential areas, hats, bazaars, roads, factories, sewage centers are being constructed. From sources like oil tankers, toxins such as metals, lead, mercury, zinc and chromium are constantly falling into the water.
On the other hand, when people in rural areas are aware of surface water contamination, they are suffering from arsenic when they start using tap water. In addition, the surface water is polluted due to excess pesticide use. These pesticides contain nitrogen, potassium and phosphorus. Using excess pesticides, it poisons the water inside the soil. The level of water contamination within the urban area has gone to critical levels.
Chemicals, heavy metals, rust, lead, cadmium, mixed with water, cannot be eliminated by just boiling. It is important to identify the substance in the water. After that, the purification system has to be taken separately. Separate measures have to be taken to purify the water.
Proper and scientific management is needed to reduce the salinity level of water in coastal areas and make it safe and suitable for drinking. But the people of the coastal region are always privileged. So the people of that region are now facing a life-threatening crisis for water. The development of more effective strategies to disinfect arsenic in tube well water has become urgent.
It is mandatory to set up a refinery or effluent treatment plant (ETP) with each factory. The use of excessive pesticides in agricultural land should be minimized. The government should take effective steps to protect groundwater. At the same time, everyone should be aware that there is no garbage dump. Everyone should be encouraged to put waste in a certain place.
Misuse of water should be prevent, use only as much as necessary. Keep in mind that, underground water is limited. In particular, dependence on groundwater should be minimized in agriculture. Rainwater harvesting should be taken into account so that it can be used in the future. Only then, we can easily meet water demand and prevent underground water pollution.
(Nazmunnaher Nipa, Student, Department of Environmental Science & Engineering, Jatiya Kabi Kazi Nazrul Islam University, Trishal, Mymensingh; e-mail: [email protected])
