Water Pollution

water

What Is Water Pollution?

DEFINITION

Water pollution is defined as the presence in groundwater of toxic chemicals and biological agents that exceed what is naturally found in the water and may pose a threat to human health and/or the environment. Additionally, water pollution may consist of chemicals introduced into the water bodies as a result of various human activities. Any amount of those chemicals pollutes the water, regardless of the harm they may pose to human health and the environment.

Causes

Many of the chlorinated solvents commonly used in industry (such as PCE, TCE, 1,1,1-TCA) are examples of such chemicals polluting our waters exclusively due to human activities. Another example is MTBE (Methyl-tert-butyl-ether), a gasoline oxygenate that is currently banned in the U.S. Regardless of their provenance, the chemicals or biological agents causing water pollution are generically referred to as water pollutants.The chemical and biological agents represent the main causes of water pollution and are generically referred to as water pollutants. 

Any kind of water can become polluted, regardless of its size or location. This includes lakes from remote areas or huge water bodies and is due to the air transportation of pollutant particles and their transfer into precipitation water. The groundwater and surface water consist of swimming pools, ponds, lakes, creeks, rivers, seas, and oceans that may all become polluted at some point. Due to the quick diffusion and dissipation of contamination and the faster natural degradation processes, the bigger the water body is, the shorter the time required for naturally cleansing the pollution and recovery.

Types of Water Pollution

There are various types of water pollution based on the various causes of water pollution. Various classifications can be made, based on various water pollution causes:

1. The type of the water pollutants – based on this classification criteria, water pollution can be:

I) Chemical – when various chemicals are the water pollution causes. The following chemicals are the most common water pollutants:

• Crude oil and various petroleum products (including gasoline, diesel fuel, kerosene, motor and lubricating oils, jet fuel). These compounds are lighter than water and thus always sit on top of water forming sheens of “free product”. However, part of these compounds dissolve in water and, even in small amounts may be harmful and at the same time may remain unnoticeable by the eye.
• Fertilizers (including nitrates and phosphates) – while small amounts are useful to life, higher amounts of nitrates and phosphates in water are only beneficial to algae and harmful microorganisms and are poisonous to human and aquatic life. These contaminants cannot be seen themselves in water (as they do not form sheens or color the water), but their effects can. The typical effect of water pollution by fertilizers (usually through agricultural runoff) is the fast and abundant water growth.
• Chlorinated solvents (including TCE, PCE, 1,1,1-TCA, carbon tetrachloride, Freons) which sink in water (are denser than water) and are quite persistent and toxic. These compounds thus, cannot be seen by the eye, in contrast with petroleum products that are easily seen as sheens on top of water surface.
• Petroleum solvents (including benzene, toluene, xylenes, ethylbenzene)
• Other organic solvents and chemicals (such as acetone, methyl ethyl ketone, alcohols such as ethanol, isopropanol; or oxygenate compounds such as MTBE)
• Antibiotics and other pharmaceutical products;
• Perchlorate – perchlorate salts are used in rocket fuels, as well as many other applications such as fireworks, explosives, road flares, inflation bags, etc. This contaminant is usually associated with military bases, construction sites (when explosives are used). However, natural formation in arid areas may account for perchlorate in water, too (e.g., in Chile, Texas or California where natural formation of perchlorate has been observed)
• Trihalomethanes – these are usually byproducts of water chlorination and may pollute groundwater and surface water via leaking sewer lines and discharges. Examples of such compounds are: chloroform, bromoform, dichlorobromomethane;
• Metals and their compounds – of higher health risk are the organo-metal compounds which may form when metals from water react with organic compounds from water. Common examples include Hg, As, and Cr poisoning of water. Thus, if water is polluted with both metals and organic compounds the health risk is higher. And so is the effect of water pollution on aquatic life.
• Pesticides/insecticides/herbicides – comprise a large number of individual chemicals that get into water due to agricultural activities directly (by spraying over large areas) or indirectly with agriculture runoff. The insecticide DDT is a typical example of such type of water pollutant.
• PCBs – in spite of their recent ban, their ubiquitous environmental presence makes these contaminants usually associated with urban runoffs.

II) Radiological – when radioactive materials are the water pollutant causes.

III) Biological – when various microorganisms (e.g., bacterial species and viruses), worms, and/or algae occurring in a large number are the water pollution causes. This type of pollution is caused by decaying organic material in water, animal wastes, as well as improper disposal of human wastes.

2. The type (grouping) of the source of water pollutants:

POINT SOURCES

These are localized sources like an industrial process, a mining activity, etc. These sources are usually regulated so that the effect may be predicted and the impact minimized. However, accidental leaks and spills are an exception to that.

NON-POINT SOURCES

These are unidentified sources from which pollutants are carried away by water discharges and runoffs. Non-point pollution may involve a broad range of pollutants, but in lower amounts than the point sources.

Sources of Water Pollution

The main sources of pollution are all resulted from the disposal of chemical substances coming from medical, industrial and household waste, chaotic agricultural fertilizers disposal and accidental oil spills that pollute the water to a large extent.

Examples of major water pollutants that affect the health of humans are:

• the numerous infectious agents (bacteria, viruses, and parasites) that contaminate the water through sewage, human waste, and animal excreta
• radioactive waste that contains highly toxic materials such as uranium, thorium, and radon. This waste is a major water pollutant resulted from mining activities, power plants or natural sources 
• the chemical substances that contaminate the water. These chemicals can be either organic - pesticides, plastic, oil, detergents, etc. - coming from domestic, industrial or agricultural waste, or inorganic - acids, metals, salts - domestic and industrial effluents.

Examples of major water pollutants that affect the ecosystem only are the following:

• plant nutrients like phosphates and nitrates that form various chemical fertilizers, sewage, and manure
• oxygen-demanding manures and agricultural waste resulted from sewage and agricultural run-offs
• sediments in the soil (silt) following soil erosion, and heated waters used in several industries and power plants.

How Does Water Pollution Affect Us?

Water pollution may cause a large variety of diseases and poses a serious problem for human health. This is mainly because we may get exposed to polluted water in various ways, including, but not necessarily limited to: 

• Drinking polluted water
• Bathing or showering in polluted water
• Swimming in polluted water
• Breathing the vapors of a polluted water while sitting next to a polluted water source
• Consuming polluted food (meat and/or vegetables) affected by polluted water
• Consuming meat from animals fed with polluted water of food affected by polluted water (e.g. vegetables irrigated with polluted water or grown in an area with polluted groundwater)

Diseases

The effects of water pollution may appear immediately after exposure and be more or less violent in the case of drinking water with a high amount of pollutants. On the other hand, the effects may appear some time after repetitive exposure to water contaminated with lower amounts of pollutants. The health effects of drinking contaminated water may range from simple intoxication and stomach aches to deadly diseases or sudden death.

What is Groundwater Pollution?

Groundwater pollution occurs as a result of release of pollutants into the ground to natural underground water reservoirs known as aquifers. Once the pollutants released find their way into groundwater, they cause contamination. It is a type of water pollution that is mainly caused by release of substances either intentionally or accidentally through anthropogenic activities or natural causes.

The pollutants usually move within an aquifers depending on biological, physical, and chemical properties. Processes such as diffusion, dispersion, adsorption, and the speed of moving water often facilitates the movement. But in general, the movement of the contaminants within an aquifer is usually slow and as such, their concentration tends to be high and in a form called a plume. As the plume spreads it might connect with springs and ground wells making them unsafe for human consumption. Hence, this article discusses the causes, effects and solutions to underground water pollution

Causes of Groundwater Pollution

1. Natural Sources

Naturally occurring substances found in the soils and rocks can be dissolved in water causing contamination. This substances are sulfates, iron, radionuclides, fluorides, manganese, chlorides and arsenic. Others such as the decaying materials in the soil may seep in underground water and move with it as particles.

Reports by WHO indicate that the most common pollutants are fluoride and arsenic. Natural cause of pollution can be tested using the Groundwater Assessment Platform (GAP). GAP estimates contamination levels using environmental, geological and the topographical data.

2. Septic Systems

Across the world, septic systems are the main cause of pollution of underground water. The pollutants are out flow from privies, septic tanks and the cesspools. 25% of household in the USA, for instance, heavily depend on the septic systems to dispose of their waste. This huge number of users relying on the system makes it one of the main pollutants.

Additionally, improperly designed and leaking septic systems release contaminants such as nitrates, oils, bacteria, chemicals, detergents and viruses into underground water. Commercial septic tanks pose even a much bigger threat because they release organic chemicals such as trichloroethane. Laws in most countries require the septic tank to be constructed far from the water sources to prevent contamination but at times this is not usually the case.

3. Hazardous waste Disposal

Hazardous wastes such as photographic chemicals, motor oil, cooking oil, paint thinners, medicines, swimming pool chemicals, paints, and garden chemicals should not be disposed into septic tanks or directly into the environment as they cause serious contamination. These chemicals should be disposed of with the help of a licensed hazardous waste handler.

4. Petroleum Products

Petroleum storage tanks are either located underground or above ground. Also, the transportation of petroleum products is mainly done underground using pipeline. Leakages from this substances can lead to contamination of water. In USA it is estimated that 16,000 chemical spills each year are from trucks, storage containers and train spillages especially when transferring oil. The chemicals spilled become diluted with water and seep into the ground and may cause groundwater contamination.

5. Solid Waste

Palmer Developmental Group estimated that in developing countries approximately 0.3 to 0.6 kg/person/day of waste is released into the ground. On the hand, in developed countries 0.7 to 1.8 kg/person/day is released. The chemicals from this substances are leached into the ground water through precipitation and surface run off.

The wastes can also be collected and taken to landfills. If the landfills lack a clay liner and leachate the chemicals from the wastes will leach and pose a threat to the groundwater.

6. Surface impoundments

These are shallow lagoons used to store liquid wastes. The USA, for example, has over 180,000 surface impoundments which can pose a threat to ground water. Therefore, the impoundments are required to have clay liners or leachates to prevent the leaching. In some cases the leachates may be defective and leakages may occur leading to contamination of water.

7. Agricultural Chemicals

Millions of tons of agricultural chemicals such as fertilizers and pesticides are used worldwide to increase crop production. Other institutions such as the golf courses also use these chemicals. Excessive use of these chemicals can lead to contamination of groundwater. Chemicals such as pesticides are known to remain in the ground for years and when diluted with the rain water they seep deeper into the groundwater.

8. Injection wells

They have various uses ranging from collection or storm water to disposal of industrial and commercial effluents. When not properly regulated, hazardous chemicals can be disposed of from injection wells. For this reason, if not properly located, regulated, and designed; they can cause contamination of ground water.

9. Other causes

Other causes of ground pollution are abandoned wells which can act as a pathway for contaminants to reach the aquifers. Also poorly constructed wells that may lack proper casing and covers may cause ground water contamination that is pollutants find their way into such wells. Another cause of pollution is mining activities where through precipitation the soluble minerals can be leached from the sites to the ground water.

Effects of Groundwater Pollution

1. Health Issues

Contaminated ground water have detrimental effects on health. In areas where septic tanks installation is not set up correctly, the human waste may contaminate the water source. The waste may contain hepatitis causing bacteria that may lead to irreversible damage to the liver.

Also, it may cause dysentery which leads to severe diarrhea, dehydration and in some cases death. Additional health problems include poisoning that may be as a result of use of excessive pesticides and fertilizers or natural chemicals. The chemicals leach into water sources and poison them. Drinking of water from such a source may lead to serious health effects.

2. Affects economic growth

Contamination of ground water sources renders the area incapable of sustaining plant, human, and animal life. The population in the area reduces and the land value depreciates. Another effect is that it leads to less stability in industries relying on ground water to produce their goods.

Therefore, the industries in affected areas will have to outsource for water from other regions which may turn out to be expensive. In addition, they may be forced to close down due to the poor quality of water.

3. Can lead to damaging impacts on the environment such as aquatic systems and the overall ecosystem

Groundwater pollution can lead to devastating environmental changes. One such alteration is loss of certain nutrients that are essential for self-sustenance of the ecosystem. Also, when the pollutants mix with water bodies, alteration of the aquatic ecosystem may also occur. Aquatic animals such as fishes may die off quickly as a result of too much contaminants in the water bodies.

Animals and plants using the contaminated water may also be affected. Toxic substances accumulate with time in the aquifers and once the prime spreads it may render the ground water unsuitable for human and animal consumption. The effects are serious especially in people who rely on groundwater during drought periods.

Solutions of Groundwater Pollution

1. Legislation

There are federal laws in most countries that help in protecting the quality of ground water. Safe Drinking and Clean Water regulations should ensure protection of drinking water by establishing measures for them to meet the health standards.

2. The use of water cleaning systems

Point-of-use treatment systems should be installed in outlets that dispense water for human consumption. The techniques used include chemical disinfection, boiling, solar distillation, filtration, ozone water disinfection, activated charcoal absorption and ultraviolet disinfections. Arsenic Removal Filters (ARFs) are usually installed to remove arsenic compounds present. Maintenance of this filters is essential to ensure that the drinking water is always safe.

Ground water Remediation is also another management technique. The biological treatment techniques employed are bioaugmentation, bioslurping, bioventing, phytoremediation and biosparging. Chemicals techniques such as ion exchange, ozone gas injection, membrane separation and chemical precipitation can also be used.

3. Proper management of the sources of pollution

The landfills should be designed with proper clay and leachates. The maintenance should be done regularly. The location of the landfill should also be far from groundwater areas. Further, any hazardous wastes should not be dumped in the landfill unless it is designed for that purpose.

In constructing and managing underground storage tanks, it is important to comply with the set regulations and policies to avoid contamination or even law suits. A containment device that acts as a leak back up should be put in place and any unused underground tanks should be removed. Underground pipelines installation should be designed professionally. Inspections should be done regularly and causes of corrosion or leakages noted should be resolved immediately.

4. Recycling

Most landfills in various countries have a recycling plant nearby. Therefore, used petroleum products should be taken to such places. Apart from oil, other recyclable materials such as plastic, bottle and paper wastes can also be taken to recycling plants. The state should provide designated recycling pick up areas in places that they are not established.

Together with other environmental organizations, the state can mobilize people to participate in the recycling initiative. They can do this through holding awareness campaigns and educating communities of the importance of recycling.

What is Water Pollution?

The water they say is life, and indeed they were right. With about 70% of the earth’s cover being water, it undeniably becomes one of our greatest resources. As young students, we learned about the various ways to conserve water; coming to think of it, water is used in almost every important human chores and processes. It is an important element in both domestic as well as industrial purposes. However, a closer inspection of our water resources today, give us a rude shock.

Infested with waste ranging from floating plastic bags to chemical waste, our water bodies have turned into a pool of poison. In simple words, the contamination of water bodies means water pollution. Thereby the abuse of lakes, ponds, oceans, rivers, reservoirs, etc is water pollution. Pollution of water occurs when substances that will modify the water in a negative fashion are discharged in it. This discharge of pollutantscan be direct as well as indirect.

Water pollution is an appalling problem, powerful enough to lead the world on a path of destruction. Water is an easy solvent, enabling most pollutants to dissolve in it easily and contaminate it. The most basic effect of water pollution is directly suffered by the organisms and vegetation that survive in water, including amphibians. On a human level, several people die each day due to consumption of polluted and infected water.

As per the Economist report (dated 2008) each day over 1000 children die of diarrheal sickness in India and the numbers have only increased alarming in the last five years. Water is polluted by both natural as well as man-made activities. Volcanic eruptions, earthquakes, Tsunamis, etc are known to alter water and contaminate it, also affecting ecosystems that survive under water.

Various Sources of Water Pollution

There are various classifications of water pollution. The two chief sources of water pollution can be seen as Point and Non-Point.

Point refers to the pollutants that belong to a single source. An example of this would be emissions from factories into the water.

Non-Point, on the other hand, means pollutants emitted from multiple sources.Contaminated water after rains that has traveled through several regions may also be considered as a Non-point source of pollution.

Various Causes of Water Pollution

1. Industrial waste

Industries produce a huge amount of waste which contains toxic chemicals and pollutants which can cause air pollution and damage to us and our environment. They contain pollutants such as lead, mercury, sulfur, asbestos, nitrates, and many other harmful chemicals.

Many industries do not have a proper waste management system and drain the waste in the fresh water which goes into rivers, canals and later into the sea. The toxic chemicals have the capability to change the color of water, increase the number of minerals, also known as eutrophication, change the temperature of water and pose a serious hazard to water organisms.

2. Sewage and wastewater

The sewage and wastewater that is produced by each household is chemically treated and released into the sea with fresh water. The sewage water carries harmful bacteria and chemicals that can cause serious health problems. Pathogens are known as a common water pollutant; The sewers of cities house several pathogens and thereby diseases.

Microorganisms in water are known to be causes of some very deadly diseases and become the breeding grounds for other creatures that act as carriers. These carriers inflict these diseases via various forms of contact onto an individual. A very common example of this process would be Malaria.

3. Mining activities

Mining is the process of crushing the rock and extracting coal and other minerals from underground. These elements when extracted in the raw form contains harmful chemicals and can increase the number of toxic elements when mixed up with water which may result in health problems. Mining activities emit a large amount of metal waste and sulphides from the rocks which is harmful to the water.

4. Marine dumping

The garbage produced by each household in the form of paper, aluminum, rubber, glass, plastic, food is collected and deposited into the sea in some countries. These items take from 2 weeks to 200 years to decompose. When such items enter the sea, they not only cause water pollution but also harm animals in the sea.

5. Accidental oil leakage

Oil spill poses a huge concern as a large amount of oil enters into the sea and does not dissolve with water; thereby opens problem for local marine wildlife such as fish, birds and sea otters. For e.g.: a ship carrying a large quantity of oil may spill oil if met with an accident and can cause varying damage to species in the ocean depending on the quantity of oil spill, size of the ocean, the toxicity of pollutant.

6. The burning of fossil fuels

Fossil fuels like coal and oil when burnt produce a substantial amount of ash in the atmosphere. The particles which contain toxic chemicals when mixed with water vapor result in acid rain. Also, carbon dioxide is released from the burning of fossil fuels which result in global warming.

7. Chemical fertilizers and pesticides

Chemical fertilizers and pesticides are used by farmers to protect crops from insects and bacterias. They are useful for the plant’s growth. However, when these chemicals are mixed up with water produce harmful for plants and animals. Also, when it rains, the chemicals mix up with rainwater and flow down into rivers and canals which pose serious damages for aquatic animal

Leakage from sewer lines

A small leakage from the sewer lines can contaminate the underground water and make it unfit for the people to drink. Also, when not repaired on time, the leaking water can come on to the surface and become a breeding ground for insects and mosquitoes.

9. Global warming

An increase in earth’s temperature due to the greenhouse effect results in global warming. It increases the water temperature and results in the death of aquatic animals and marine species which later results in water pollution.

10. Radioactive waste

Nuclear energy is produced using nuclear fission or fusion. The element that is used in the production of nuclear energy is Uranium which is a highly toxic chemical. The nuclear waste that is produced by radioactive material needs to be disposed of to prevent any nuclear accident. Nuclear waste can have serious environmental hazards if not disposed of properly. Few major accidents have already taken place in Russia and Japan.

11. Urban development

As the population has grown, so has the demand for housing, food, and cloth. As more cities and towns are developed, they have resulted in increasing use of fertilizers to produce more food, soil erosion due to deforestation, increase in construction activities, inadequate sewer collection, and treatment, landfills as more garbage is produced, increase in chemicals from industries to produce more materials.

12. Leakage from the landfills

Landfills are nothing but a huge pile of garbage that produces the awful smell and can be seen across the city. When it rains, the landfills may leak and the leaking landfills can pollute the underground water with a large variety of contaminants.

13. Animal waste

The waste produced by animals is washed away into the rivers when it rains. It gets mixed up with other harmful chemicals and causes various water-borne diseases like cholera, diarrhea, jaundice, dysentery and typhoid.

14. Underground storage leakage

Transportation of coal and other petroleum products through underground pipes is well known. Accidentals leakage may happen anytime and may cause damage to the environment and result in soil erosion.

Water pollutants also include both organic and inorganic factors. Organic factors include volatile organic compounds, fuels, waste from trees, plants etc.  Inorganic factors include ammonia, chemical waste from factories, discarded cosmetics etc. The water that travels via fields is usually contaminated with all forms of waste inclusive of fertilizers that it swept along the way. This infected water makes its way to our water bodies and sometimes to the seas endangering the flora, fauna and humans that use it along its path.

The current scenario has led to a consciousness about water preservation and efforts are being made on several levels to redeem our water resources. Industries and factory set-up’s are restricted from contaminating the water bodies and are advised to treat their contaminated waste through filtration methods. People are investing in rainwater harvesting projects to collect rainwater and preserve it in wells below ground level.

Water Pollution is common, and is an area of high alert. Water needs to be preserved and respected today, for us to live a tomorrow.