What are the Causes of Water Pollution?

Water pollution has a serious impact upon the environment, which in turn affects animals, humans, and plants; the causes of water pollution are many; as well as being about the kinds of things that are put into streams and lakes, water pollution can also involve the quantity of such goods. For example, a small concentration of chemical poured into the ocean would not have serious effects, but a tanker full of oil can very quickly have an effect upon the water quality.

Water pollution often does not start in the water course itself. The oceans, for example, are polluted by rivers carrying pollutants from gardens, factories, shipping and polluted rainwater. Chemicals being released by factory chimneys is actually one of the biggest causes of water pollution: the smoke is released into the air, which falls to earth as rain.

Causes of Water Pollution

This is a list of some of the causes of water pollution

  • Discharging of effluent and business waste into surface water instead of ‘foul water’ drains.
  • Spills from chemical containers, or oil tankers
  • Ground run-off from pesticides and industrial farm products
  • Waste such as milk which is used humans, but can seriously damage the environment if not treated properly.
  • Waste which is normally disposed of well, but has been discharged in too large a quantity

How much of the substance is put into a quantity of water is just as important as the type of substance.

There are two ways in which pollution can reach a water course: the first is pollution coming from a single source, such as a discharge pipe, which is known as a point-source pollution. Smoke from factories, oil spills, and chemicals poured down a drain are other examples of the point-source pollution. Most water pollution is found to have a number of separate sources, often scattered across a large area—this is known as nonpoint source pollution.

Types of Water Pollution

Water pollution affects different waterways in a variety of ways. Surface waters, for example, such as lakes, oceans and rivers, are not easily damaged by small quantities of pollution, but they are vulnerable to large-quantity spills.

Groundwaters are waters that actually travel underground, and move through rock structures, and also pool into rock formations known as aquifers. These aquifers supply rivers, and therefore form much of the source of Earth’s drinking water. Groundwater can become much more easily polluted, for example through run-off from gardens and rainwater. A study of Iowa’s water in 1996 found that more than 50 percent of all the state’s groundwater aquifers were contaminated by weed killer, and other studies have shown that about half of all ocean pollution is the result of sewage and waste water pumped from cities.

Biological Pollution

One of the most unexpected causes of water pollution is "alien species" or plants and fauna which are not native to the soil. These often lack predators, and so become wild, stripping the soil of nutrients and making it more prone to backwash.