PHLT612: Special Issues in Public Health – II
Unit 02: - Water Pollution: Definition, Sources, Classification of Water Pollutants –
Organic Waste, Oxygen Demanding Waste, Disease Causing Wastes, Synthetic Organic
Compounds. Sanitation, Inorganic Pollutants Suspended Solids and Sediments,
Radioactive Materials, BOD, COD, Water Waste Treatment – Primary, Secondary and
Tertiary.
Water pollution
Water pollution is the contamination of water sources by substances which make the water unusable for
drinking, cooking, cleaning, swimming, and other activities. Pollutants include chemicals, trash, bacteria,
and parasites. All forms of pollution eventually make their way to water. Air pollution settles onto lakes and
oceans. Land pollution can seep into an underground stream, then to a river, and finally to the ocean. Thus,
waste dumped in a vacant lot can eventually pollute a water supply.
Sources of Water Pollution
1. Sewage (Wastewater)
Sewage is another name for wastewater from domestic and industrial processes. Despite strict regulatory
control, the Environment Agency data shows that the water and sewage industry accounted for almost a
quarter of the serious water incidents in England and Wales in 2006.
, 2. Agricultural Pollution
The agriculture industry covers 76% of the land area of England and Wales. Agricultural processes such as
uncontrolled spreading of slurries and manure, disposal of sheep dip, tillage, ploughing of the land, use of
pesticides and fertilisers can cause water pollution. Accidental spills from milk dairies can also affect the
quality of water.
3. Oil Pollution
Every year there are about 3,000 pollution incidents involving oil and fuels in England and Wales. Oil
spillages affect water quality in a number of ways. Oil can make drinking water unsafe to drink. A
substantial amount of oil released into oceans and seas will destroy wildlife and the ecosystems that sustain
them. Oil spills also reduce oxygen supplies within the water environment. The main causes of oil related
water pollution are:
a) loss from storage facilities
b) spillage during delivery
c) deliberate disposal of waste oil to drainage systems
4. Radioactive Substances
Radioactive waste is another source of water pollution. Radioactive substances are used in nuclear power
plants, industrial, medical and other scientific processes. They can be found in watches, luminous clocks,
television sets and x-ray machinery. There are also naturally occurring radioisotopes from organisms and
within the environment. If not properly disposed of, radioactive waste can result in serious water pollution
incidents.
5. River dumping
Lots of people dump supermarket trolleys, bicycles, garden cuttings and electronic waste into rivers or
riverbanks. This is illegal and offenders may be charged for fly-tipping if caught. River dumping not only
causes water pollution; it also harms wildlife and increases the risk of flooding. Fly-tipping (this includes
river dumping) is a criminal offence. In the most severe cases, it can attract a maximum fine of £50,000 or a
5-year jail term.
6. Marine Dumping
The Worldwide Fund for Nature (WWF) estimates that a staggering amount of waste enters into the sea
Unit 02: - Water Pollution: Definition, Sources, Classification of Water Pollutants –
Organic Waste, Oxygen Demanding Waste, Disease Causing Wastes, Synthetic Organic
Compounds. Sanitation, Inorganic Pollutants Suspended Solids and Sediments,
Radioactive Materials, BOD, COD, Water Waste Treatment – Primary, Secondary and
Tertiary.
Water pollution
Water pollution is the contamination of water sources by substances which make the water unusable for
drinking, cooking, cleaning, swimming, and other activities. Pollutants include chemicals, trash, bacteria,
and parasites. All forms of pollution eventually make their way to water. Air pollution settles onto lakes and
oceans. Land pollution can seep into an underground stream, then to a river, and finally to the ocean. Thus,
waste dumped in a vacant lot can eventually pollute a water supply.
Sources of Water Pollution
1. Sewage (Wastewater)
Sewage is another name for wastewater from domestic and industrial processes. Despite strict regulatory
control, the Environment Agency data shows that the water and sewage industry accounted for almost a
quarter of the serious water incidents in England and Wales in 2006.
, 2. Agricultural Pollution
The agriculture industry covers 76% of the land area of England and Wales. Agricultural processes such as
uncontrolled spreading of slurries and manure, disposal of sheep dip, tillage, ploughing of the land, use of
pesticides and fertilisers can cause water pollution. Accidental spills from milk dairies can also affect the
quality of water.
3. Oil Pollution
Every year there are about 3,000 pollution incidents involving oil and fuels in England and Wales. Oil
spillages affect water quality in a number of ways. Oil can make drinking water unsafe to drink. A
substantial amount of oil released into oceans and seas will destroy wildlife and the ecosystems that sustain
them. Oil spills also reduce oxygen supplies within the water environment. The main causes of oil related
water pollution are:
a) loss from storage facilities
b) spillage during delivery
c) deliberate disposal of waste oil to drainage systems
4. Radioactive Substances
Radioactive waste is another source of water pollution. Radioactive substances are used in nuclear power
plants, industrial, medical and other scientific processes. They can be found in watches, luminous clocks,
television sets and x-ray machinery. There are also naturally occurring radioisotopes from organisms and
within the environment. If not properly disposed of, radioactive waste can result in serious water pollution
incidents.
5. River dumping
Lots of people dump supermarket trolleys, bicycles, garden cuttings and electronic waste into rivers or
riverbanks. This is illegal and offenders may be charged for fly-tipping if caught. River dumping not only
causes water pollution; it also harms wildlife and increases the risk of flooding. Fly-tipping (this includes
river dumping) is a criminal offence. In the most severe cases, it can attract a maximum fine of £50,000 or a
5-year jail term.
6. Marine Dumping
The Worldwide Fund for Nature (WWF) estimates that a staggering amount of waste enters into the sea
