What is Water Pollution?

Transcription

1 Sources and Types

2 What is Water Pollution? The contamination of water bodies (for example; lakes, rivers, oceans, aquifers and ground water). Occurs when pollutants are added directly or indirectly into water bodies without adequate treatment to remove harmful compounds.

3 Water pollution affects plants and organisms living in these bodies of water. The effect is damaging not only to individual species and populations, but also to natural biological communities.

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5 Why Do We Care About Water Pollution? Water pollution is the leading worldwide cause of disease and death. Some scary statistics Accounts for the death of more than 14, 000 people daily. For example, 700 million people living in India have no access to a proper toilet 1000 children a day, die in India from diarrheal sickness, caused by water pollution. 90% of China s cities suffer from dome degree of water pollution and nearly 500 million people lack access to safe drinking water. There are problems in developed countries as well. For example, in the US, 45% of streams, 47% of lakes and 32% of bays are polluted in some way.

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7 Clean vs. Polluted Water Water is typically referred to as polluted when it is impaired by biological contaminants (such as disease) and does not support human use (for example, can not be used as drinking water). Is can also be considered polluted if it cannot support living communities of animals and plants. There are natural cases of polluted water. Natural phenomena, such as volcanoes, algal blooms, storms and earthquakes also cause major changes in water quality and the ecological status of water.

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9 Sources of Pollution Point Sources Refers to a contaminant that enters a waterway from a single, identifiable source. For example, a pipe or a ditch. This can include discharge/waste from a sewage treatment plant, construction sites, factories or storm drains. Due to their specific location pollution can be more easily prevented in point source pollution sites.

10 Sources of Pollution Non-point Sources Pollution that does not originate from a single discrete source. Cumulative effect of small amount of contaminant gathered from a large area. For example, when nitrogen fertilizer leaks into groundwater from a farmers field. Another common example is urban runoff. When storm water washes over urban area, such as a parking lot, road or highway, it can carry contaminants to other locations. This is much harder to control because the direct source is unknown

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12 Types of Pollutants Pathogens Coliform bacteria (bacteria that grows together in large amounts) and micro-organisms are the common sources of pathogen water pollution. High levels of pathogens may result from inadequately treated sewage discharges.

13 Types of Pollutants Pathogens (continued) In some less developed countries, sewage is only filtered, not chemically treated. This is called primary treatment and does not remove the bacteria in the water. In developed countries, sewage will all go through a secondary treatment of removing the bacteria. However, contamination can still take place when sewage pipes overflow. Pathogens are also found in water sources next to poorly manage livestock farms.

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15 Examples of Pathogens Burkholderia pseudomallei a type of bacteria that causes meiliodosis, which damges the lungs, bones, liver and spleen. Cryptosporidium parvum a type of bacteria that causes excessive diarrhea (up to 10 litres!) Giardia lambia pathogen that lives in the small intestine, takes nutrients from it s host.

16 Chemical Pollutions - Organic Organic water pollutants are made from naturally occurring products and include: Detergents Disinfection products, mostly found in disinfected water ex. Chloroform Food processing wastes, such as fats and grease Fuels including gasoline, diesel fuel, jet fuel Industrial solvents Compounds found in cosmetic and personal hygiene products.

17 Chemical Pollutants - Inorganic Inorganic water pollutants are made from man-made products and include: Discharges from power plants (have a high acid level) Ammonia from food processing factories Chemical waste as industrial by- products Fertilizers - contain nutrients such as nitrates and phosphates from agriculture Heavy metals from motor vehicles Silt in runoff from construction sites

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19 Macroscopic Pollution Are large, visible items polluting water Sometimes called floatables. Include items such as: Trash or garbage (e.g. paper, plastic, or food waste) discarded by people on the ground. This can then get blown into or flow into surface water. Nurdles, small plastic pellets. If they get released into the water they are almost impossible to contain. Even a shipwreck is considered macroscopic pollution.

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21 BP Oil Spill e=active

22 Thermal Pollution Thermal pollution is the rise or fall in the temperature of a natural body of water caused by human influence. Thermal pollution, unlike chemical pollution, results in a change in the physical properties of water. A common cause of thermal pollution is the use of water as a coolant by power plants and industrial manufacturers. When water temperatures increase, it can decrease oxygen amounts, which kills fish. Thermal pollution can also be caused by the release of very cold water from the base of reservoirs into warmer rivers.

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