Water Pollution

Water pollution is the contamination of water bodies (rivers, streams, oceans, underground water, and aquifers).

Causes of Water Pollution

  1. Marine dumping
  2. Industrial waste
  3. Sewage (mainly from households)
  4. Nuclear waste
  5. Oil pollution
  6. Underground storage
  7. Leaks
  8. Mining (surface mining, toxics, acids, sediment)
  9. Fertilizers
  10. Bacteria from livestock
  11. Food processing
  12. Salt from soil irrigation (agriculture)

These are explained below.

We cannot live without water. With all the water around us, less than 1 percent is accessible. Yet 80% of the world’s wastewater is dumped back into the environment, polluting rivers, lakes and oceans. This places our health in jeopardy.

Polluted water could look muddy, smell bad, and are littered with garbage; or it could look clean but filled with harmful chemicals. This water is unsafe to drink or swim in. Plus, the fish in it is unsafe to eat. Polluted waters can cause harm to both humans, animals and living organisms that depend on the water to live.

Oil and natural gas leak into ocean and lakes naturally or more by human activity. The oil washes up on nearby beaches and seep into the waterways. Runoff from the oil can create fertile environment for cyanobacteria, blue-green algae. Oil spills kill plants, animals and aquatic organisms.
Harmful algal bloom” happens when the blue-green algae reproduce rapidly, and prevent organisms such as plants and fish from living in the oceans. This can also happen when fertilizers, a material to help plants grow larger and faster, contaminate waterways. Fertilizers contains large amounts of nitrogen and phosphorus. Rainwater washes the fertilizers into the water ways and cause cyanobacteria to form.
Mining and drilling cause water pollution. Toxic chemicals such as sulfur is released. It kills plants fish, and other aquatic organisms. Other chemical waste are released from buried radioactive waste from nuclear power plants. Also, some bacteria grow in the water, they do not need oxygen to function. They produce certain gases, one such is hydrogen sulphide which causes the polluted water to smell like rotten eggs.
Water pollution can trap animals, especially birds making them unable to fly to access food.
A poor sewer system or treatment plant can cause pollution to rivers and water source.
Power plants uses a lot of water and release huge amount of heated water into the rivers and lakes. This changes the temperature of the water and prevent fish eggs from hatching as well as contribute to harmful algal blooms.
Garbage piles float on the water.
Floating trash or garbage in water harms turtles and other animals that could mistaken the trash for food.

These show that there are two types of water pollution: surface water pollution and groundwater pollution.

Pollution can causes:

  1. Toxic water,
  2. Thermal heating, and
  3. Diseases by contaminating water or when people swim in polluted water or come in contact with chemically polluted water.

Water Pollution video

Discussion questions:

  1. What is water pollution?
  2. Why should we be very concern when we see oil spills?
  3. What is “algal bloom”?
  4. How can we determine if the water in a particular river is polluted?
  5. Why do some polluted waters smell like rotten eggs?