Causes Of Water Pollution

Causes Of Water Pollution:

OIL SPILLS:

Among the most dangerous of all water pollutants is fuel oil. Oil spills from tankers at sea or leaks from underground storage tanks on land are very difficult to control as oil tends to spread very fast, affecting a large area in a very short time. They are a major menace to the environment as they cause severe damage to surrounding ecosystems. Oil spills at sea decrease the oxygen level in the water and cause grave harm to the creatures living in the sea. Since crude oil is lighter than water, it floats on the surface and poses the threat of swift-spreading fire. Oil spills are rather common as oil tankers can meet with accidents either in deep sea or offshore, while waiting to be loaded or unloaded. During the Gulf War, several oil reservoirs were destroyed at sea and the effect on marine life was devastating. Seabirds and fish were washed ashore, their bodies covered with oil. On land crude is transported through pipelines or tankers which can get damaged and spew out crude oil over the land, thereby contaminating it.

Bioremediation is a method that is now being use to put a check to the damage done by this oil spill.

DOMESTIC SEWAGE:

Domestic sewage refers to waste water that is discarded from households. Also referred to as sanitary sewage, such water contains a wide variety of dissolved and suspended impurities.
It amounts to a very small fraction of the sewage by weight. But it is large by volume and contains impurities such as organic materials and plant nutrients that tend to rot. The main organic materials are food and vegetable waste, plant nutrient come from chemical soaps, washing powders, etc. Domestic sewage is also very likely to contain disease-causing microbes. Thus, disposal of domestic waste water is a significant technical problem. Sewage generated from the urban areas in India has multiplied manifold since 1947.
Today, many people dump their garbage into streams, lakes, rivers, and seas, thus making water bodies the final resting place of cans, bottles, plastics, and other household products. The various substances that we use for keeping our houses clean add to water pollution as they contain harmful chemicals. In the past, people mostly used soaps made from animal and vegetable fat for all types of washing. But most of today’s cleaning products are synthetic detergents and come from the petrochemical industry. Most detergents and washing powders contain phosphates, which are used to soften the water among other things. These and other chemicals contained in washing powders affect the health of all forms of life in the water.

BIOCHEMICAL OXYGEN DEMAND, OR BOD:

The amount of organic material that can rot in the sewage is measured by the biochemical oxygen demand. BOD is the amount of oxygen required by micro-organisms to decompose the organic substances in sewage. Therefore, the more organic material there is in the sewage, the higher the BOD. It is among the most important parameters for the design and operation of sewage treatment plants. BOD levels of industrial sewage may be many times that of domestic sewage. Dissolved oxygen is an important factor that determines the quality of water in lakes and rivers. The higher the concentration of dissolved oxygen, the better the water quality. When sewage enters a lake or stream, micro-organisms begin to decompose the organic materials. Oxygen is consumed as micro-organisms use it in their metabolism. This can quickly deplete the available oxygen in the water. When the dissolved oxygen levels drop too low, many aquatic species perish. In fact, if the oxygen level drops to zero, the water will become septic. When organic compounds decompose without oxygen, it gives rise to the undesirable odours usually associated with septic or putrid conditions.

EUTROPHICATION:

When fresh water is artificially supplemented with nutrients, it results in an abnormal increase in the growth of water plants. This is known as eutrophication. The discharge of waste from industries, agriculture, and urban communities into water bodies generally stretches the biological capacities of aquatic systems. Chemical run-off from fields also adds nutrients to water. Excess nutrients cause the water body to become choked with organic substances and organisms. When organic matter exceeds the capacity of the micro-organisms in water that break down and recycle the organic matter, it encourages rapid growth, or blooms, of algae. When they die, the remains of the algae add to the organic wastes already in the water; eventually, the water becomes deficient in oxygen. Anaerobic organisms (those that do not require oxygen to live) then attack the organic wastes, releasing gases such as methane and hydrogen sulphide, which are harmful to the oxygen-requiring (aerobic) forms of life. The result is a foul-smelling, waste-filled body of water. This has already occurred in such places as Lake Erie and the Baltic Sea, and is a growing problem in freshwater lakes all over India. Eutrophication can produce problems such as bad tastes and odours as well as green scum algae. Also the growth of rooted plants increases, which decreases the amount of oxygen in the deepest waters of the lake. It also leads to the death of all forms of life in the water bodies.

AGRICULTURAL RUN OFF:

The use of land for agriculture and the practices followed in cultivation greatly affect the quality of groundwater. Intensive cultivation of crops causes chemicals from fertilizers (e.g. nitrate) and pesticides to seep into the groundwater, a process commonly known as leaching. Routine applications of fertilizers and pesticides for agriculture and indiscriminate disposal of industrial and domestic wastes are increasingly being recognized as significant sources of water pollution.

The high nitrate content in groundwater is mainly from irrigation run-off from agricultural fields where chemical fertilizers have been used indiscriminately.

INDUSTRIAL EFFLUENTS:

Waste water from manufacturing or chemical processes in industries contributes to water pollution. Industrial waste water usually contains specific and readily identifiable chemical compounds. During the last fifty years, the number of industries in India has grown rapidly. But water pollution is concentrated within a few subsectors, mainly in the form of toxic wastes and organic pollutants. Out of this a large portion can be traced to the processing of industrial chemicals and to the food products industry. In fact, a number of large- and medium-sized industries in the region covered by the Ganga Action Plan do not have adequate effluent treatment facilities. Most of these defaulting industries are sugar mills, distilleries, leather processing industries, and thermal power stations. Most major industries have treatment facilities for industrial effluents. But this is not the case with small-scale industries, which cannot afford enormous investments in pollution control equipment as their profit margin is very slender.

EFFECTS OF WATER POLLUTION:

The effects of water pollution are not only devastating to people but also to animals, fish, and birds. Polluted water is unsuitable for drinking, recreation, agriculture, and industry. It diminishes the aesthetic quality of lakes and rivers. More seriously, contaminated water destroys aquatic life and reduces its reproductive ability. Eventually, it is a hazard to human health. Nobody can escape the effects of water pollution.

The individual and the community can help minimize water pollution. By simple housekeeping and management practices the amount of waste generated can be minimized.

WATER POLLUTION STATISTICS:

According to the data compiled by the World Water Assessment Program (WWAP), 2 million tons of human waste is disposed in water bodies every single day. The developing countries have a major share in water pollution, as 70 percent of the industrial waste which is dumped untreated in the water bodies comes from these developing countries of the world. The problem of groundwater pollution is also quite prominent in the United States, and agriculture is considered to be the underlying factor for this. A study carried out in the 49 states of the US revealed that nitrate was the principal contaminant of groundwater in this region. Alongside groundwater, agriculture also plays a significant role in the pollution of larger water bodies in form of surface run off. In fact, the traces of DDT, which was banned in the United States way back in 1970s, are still found in the waters of the Atlantic and the Pacific oceans. As a result of this incessant pollution of water, around 20 percent of the world population is left without proper water to drink. A study about the effects of water pollution, undertaken way back in 90s, revealed that 1,200 million people are affected the world over due to this problem. Things have changed drastically since then, and therefore it is assumed that the number of the affected people has also increased. The same study also revealed that water pollution is one of the major factors for the death of children under five every year.

Ways to Prevent Water Pollution?

While we should see to it that the government is stringent about their policies related to sewage treatment plants and methods, there are many things that we can carry out individually to prevent water pollution. Given below are a few ways to prevent water pollution:

• Toxic products like paints, automobile oil, polishes, and cleaning products should be stored and disposed off properly. As a matter of fact, it is better to use non-toxic, products for the house as far as possible. Also, never dispose off such products by throwing them into your toilet or sink.
• Dispose off your trash in a proper manner and try and incorporate the recycling habit as far as possible. Non-degradable products like tampons, sanitary napkins, and diapers should not be flushed down the toilet, for these can end up damaging the process of sewage treatment, and usually end up as litter on beaches.
• Refrain from throwing litter into streams, lakes, rivers, or seas. If you do spot litter on beaches or in water systems, after ascertaining that it is safe, collect them and dispose them off in any nearby waste disposal system.
• Try using environmentally friendly household products like toiletries, soap-based household cleaning material, and washing powder as far as possible.
• Try using natural fertilizers and pesticides as far as possible, or if not, do not overuse them or over-water gardens and lawns. This will help in reducing the pollutants that get into water systems due to runoffs.
• Automobile oil should be re-used as far as possible. Also, it is important to keep your automobile well maintained in order to prevent leakages of toxic fluids like antifreeze and oil.
• Also, actively conserve water by turning the tap off when you do not need running water, such as while brushing teeth. Apart from preventing water shortages, it lessens the amount of water that needs to be treated.
• Do not use colored bathing bars. They are known to contribute more to water pollution.
• Avoid buying packaged water as far as possible. The best policy to adopt is to carry a bottle of water when you step out of the house. You can carry one big bottle per head. This has two advantages: you eliminate your contribution to pollution related to plastic bottles, and you save money.

WATER CONSERVATION:

The most important step in the direction of finding solutions to issues of water and environmental conservation is to change people's attitudes and habits¾this includes each one of us. Conserve water because it is the right thing to do. We can follow some of the simple things that have been listed below and contribute to water conservation.

• Try to do one thing each day that will result in saving water. Don't worry if the savings are minimal¾every drop counts! You can make a difference.
• Remember to use only the amount you actually need.
• Form a group of water-conscious people and encourage your friends and neighbours to be part of this group. Promote water conservation in community newsletters and on bulletin boards. Encourage your friends, neighbours and co-workers to also contribute.
• Encourage your family to keep looking for new ways to conserve water in and around your home.
• Make sure that your home is leak-free. Many homes have leaking pipes that go unnoticed.
• Do not leave the tap running while you are brushing your teeth or soaping your face.
• See that there are no leaks in the toilet tank. You can check this by adding colour to the tank. If there is a leak, colour will appear in the toilet bowl within 30 minutes. (Flush as soon as the test is done, since food colouring may stain the tank.)
• Avoid flushing the toilet unnecessarily. Put a brick or any other device that occupies space to cut down on the amount of water needed for each flush.
• When washing the car, use water from a bucket and not a hosepipe.
• Do not throw away water that has been used for washing vegetables, rice or dals ¾ use it to water plants or to clean the floors, etc.
• You can store water in a variety of ways. A simple method is to place a drum on a raised platform directly under the rainwater collection source. You can also collect water in a bucket during the rainy season.