What are Water Pollutants?

More than two thirds of the Earth’s surface consists of water and man can’t survive without it. However, our water sources, the world over are becoming more and more contaminated with pollutants.

So what are these pollutants and how can we help to preserve the cleanliness of our water?

When Is Water Polluted?

Any kind of ‘damage’ done to water which adversely affects its quality could be considered as pollution. However, technically, water is considered to be polluted when it’s no longer fit for human consumption and/or it is harmful to the marine environment.

Types Of Pollution

There are three main types of pollution; ‘point source’ pollution, ‘non-point source’ pollution and ‘transboundary’ pollution.

Point Source Pollution

Point Source pollution occurs when there is one, definable polluting incident – for instance when an oil tanker spills its load or when someone pours a pollutant such as weed-killer down a drain. Of course there can be many such point source pollution incidents occurring in many different places at the same time.

Non-Point Source Pollution

Non-point source pollution is when pollutants enter a body of water from many different sources – for instance when chemicals used in agriculture pollute a river due to run-off from a field.

Transboundary Pollution

Transboundary pollution is when the origin of the pollutants occurs a long distance away from its effects – for instance when nuclear power stations discharge radioactive waste water which travels through the ocean to affect an area many miles away.

Types Of Water Pollutant

Any human activity which has a polluting effect on water will involve some kind of pollutant. In fact 80% of water pollutants find their way from man and the land into water. However, the most common types of pollutant can be divided into general categories.


Waste matter from man has long been a problem in terms of water pollution. For many years, raw, untreated sewage was merely pumped directly into the sea. Nowadays we have become better at filtering and treating it so that water pollution is kept to a minimum. Nevertheless, during times of bad weather and when water treatment works over-flow; sewage is still able to enter our rivers and seas.


One polluting aspect of untreated sewerage entering waterways is that there is a risk of harmful bacteria and pathogens contaminating the water. These are not only harmful to man, should they swim in infected water, but are hugely damaging to sea life such as shellfish.

Such microbiological pollution renders our water unfit for human consumption and carries the risk of contracting such water-borne diseases such as cholera and polio.

Chemical Pollutants

Pollutants such as chemical waste and waste from other industrial and petro-chemical sources are also common. Incidents such as oil spills at sea are very evident in that they hit the news headlines and are very visible, whereas others such as detergents being poured daily down our drains are unseen and generally un-noticed.

While we have stringent regulations in place to help prevent the worst of industrial contamination, other countries, such as China, are still allowing toxic chemical waste to enter the water stream. Nevertheless, it would be a mistake to only think of such ‘heavy’ polluters as the real offenders – a huge amount of chemical pollution is from individuals such as gardeners who inadvertently contaminate groundwater (the water which sinks through our ground into aquifers we can’t see), though using fertilizers and pesticides.


The amount of rubbish finding its way into our seas, oceans, rivers, lakes, and estuaries is increasing exponentially. Each year the Marine Conservation Society record growing amounts of litter, plastics, fishing debris, and other man-made items which harm aquatic life and ruin the aesthetic beauty of our water.

Radioactive Waste

Radioactive waste enters the sea in this country from Sellafield where it travels through the water to contaminate the coastal environment of Norway.

Waste from nuclear reactors has been a hugely controversial topic with contamination from war vessels the subject of long debate. Environmental campaigners have been calling for the closure of Sellafield for many years due to the link between radioactive waste and cancers.

What You Can Do To Decrease Water Pollutants

  • Don’t use chemical detergents
  • Don’t pour chemicals down the sink or drain
  • Don’t use fertilizers, pesticides, insecticides, or fungicides in the garden
  • Bag and bin your sanitary waste – do not flush down the toilet
  • Switch to buying organic food to deter farmers from using chemicals on crops
  • Notify appropriate authorities should you witness or notice any point source pollution