What Causes Water Pollution? Causes | Effects | Solutions

Written by: James Smith

Updated: March 2, 2023

In today’s article we take a look at the main causes and effects of water pollution. What can we do to protect one of the few things we rely on?

polluted ocean water

Without water, life on earth would be impossible. We can do without food for a little while, but we would not last very long without water.

We have a limited amount of water available to us, so we need to preserve what we can and take care of it well. Unfortunately, pollution threatens to destroy this precious resource and leave us in a desperate situation.

Not only does water pollution impact our lives, but it has catastrophic effects on the environment. Let’s learn more about water contamination and what we can do about it.

What is Water Pollution?

Water pollution is basically the presence of anything toxic in natural water supplies. To be regarded as pollution it has to be in a large enough quantity that it exceeds what is naturally found in the water supply. A large enough quantity that it poses a health risk to natural life and the environment.

Water pollution depends on the quantity of whatever is invading the water. Small doses may not be in a position to cause any harm. But when the pollutant comes in large quantities and at a steady rate, the clean water would be overpowered, and it would begin to affect the water and the life that it sustains.

Water pollution is anything that damages the water. There are many different forms, causes and effects of water pollution. In this guide, we are going to take a look at them.

The Types of Water That Get Polluted

There are many different types of pollution, each having a different effect. Let’s take a look at the main types of water pollution.

Surface Water

This is the most obvious type of water pollution. Surface water is the water that we can see, for example the oceans, rivers, wetlands and lakes.


A lot of water is stored underground in rock structures known as aquifers. These aquifers store the water as it travels and feeds into dams and rivers. The water stored there is called groundwater. This water becomes polluted when chemicals, like weed killers, seep into the ground.

Groundwater is particularly susceptible to non-point source pollution (see next section). When groundwater gets polluted it is extremely hard to reverse the damage done, as it sits far below the surface.

polluted river water
Polluted surface water

Sources of Water Pollution

The sources of water pollution are identified in two groups:

Point Source Pollution

This is pollution where the source can be traced to an individual location. An example of this would be a factory that releases chemicals into a river. Any source of pollution that has an identifiable location is point source.

Non-Point Source Pollution

This is water pollution where the source isn’t easily identifiable. Examples of this are rainfall or snowmelt, as they are a culmination of pollution in a wide area.

As the runoff from precipitation moves across the ground, it absorbs pollutants like fertilizers and pesticides and then deposits them in lakes, rivers, oceans, and groundwater.

The Main Causes of Water Pollution

Water pollution is a difficult problem to solve because there are so many different sources. As the world becomes more industrialized we are even creating new pollutants every day that we don’t yet fully understand.

Here’s a breakdown of the biggest offenders when it comes to water pollution in 2023.


Recent studies found that little over 9% of the world’s population do not have access to clean water, while over 2 billion people do not have access to basic sanitation. This means that their water and sewage is not properly separated or cared for. This can lead to many different diseases that kill thousands every year. In countries where there is proper sanitation, the sewage is flushed and sent far away.

However, this does not solve the problem since that sewage needs to go somewhere, and most of it ends up in the ocean. While sewage is 90% water and should be able to break down naturally, there is an alarming amount of chemicals in our sewage.

People flush plastic or paper products down the drain, and there has recently been a rise in people who take chemical medication. All of this ends up in the sewage which eventually leaks off into major water sources such as lakes, rivers and the ocean.

sewer cover

The emergence of pharmaceutical drugs in drinking water and their negative effects is actually a growing problem. The number of people on medication is at an all-time high and much of this medicine isn’t disposed of properly.

NSF International has developed a drinking water standard that they apply to special water filters that are able to filter certain pharmaceutical drugs from water. It is called NSF/ANSI 401. Worryingly, new pharmaceutical drugs are developed and end up in water all the time and these standards are having to be constantly addressed.

Landfill & Animal Waste

Pollution caused by landfills, sewage, animal waste and industrial waste like that from slaughterhouses and food processing factories is called microbial pollution.

This pollution is caused by microorganisms that occur naturally. These include bacteria, viruses (like E.coli and Giardia) and protozoa diseases like cholera.

landfill site

These bacteria and viruses get into water supplies by seeping into groundwater and surface water through run-off from rainwater. Landfill sites have to meet much stricter standards with regard to contamination these days.

This is a huge problem in developing countries that don’t have the means to sterilize drinking water supplies.


The fertilizer farmers use to spray on their crops does not stay on the farm. It seeps off into the groundwater, or the rain carries it to surface water such as nearby dams or rivers. These chemicals combined with the chemicals in the sewage allow a special kind of algae or plankton to grow.

fertilizer spraying

This harmful algal bloom is known as the red tide, since it can turn the water red. These algae deprive the water of oxygen, starving the life in those areas. This leads to large areas where nothing can live or grow. These areas are known as dead zones.

The biggest dead zone can be found in the Gulf of Mexico. That dead zone is larger than the state of Connecticut and grows bigger each year.


This water is washed down drains after you have used it. The water contains soap or detergents that people use to wash their dishes or clothes. Some of this wastewater is also discharged from factories.

wastewater pollution

Chemical Waste

This waste comes from metals, or substances used to create pipes or other infrastructure. These chemicals leak into the water and are hard to detect. This is because the effects only come to light at a much later stage.

Septic tanks are another source of chemical waste that ends up in the water. Around 1/4 of American homes have septic tanks that dispose of toilet waste.

Though each system only discards a small amount of waste into the ground, 1/4 of US homes equals around 8 million participants. Septic tanks commonly contain detergents and cleaning chemicals, but also sewage.

Radioactive Waste

Many people are terrified of radioactive waste and for good reason. This type of waste can cause cancer or even death. This waste comes from nuclear power plants and it is a major cause for concern. Radioactive waste can also take many years to reduce in toxicity.

The Fukushima nuclear power plant in Japan that went into meltdown in 2011 won’t be completely decommissioned for another 30-40 years due to its radioactive toxicity.


Plastic is a major part of our lives. We use it for almost anything and a lot of it gets thrown away every day. When our plastic waste is not thrown into a landfill, it is usually dumped in the water.

Littering is a major problem, but the plastic can be carried off by the wind, be washed away by the rain or dumped straight into the ocean.

plastic pollution in water

Recently new inventions like micro-beads used in cosmetics have been found to be extremely hazardous to marine life.

Oil Spills

Every year, thousands of oil spills contaminate our water. They’re not always big events that make the news either. Oil leaks off ships, or the rain carries traces of oil to surface waters.

This accumulated amount of oil is massive and leads to the devastation of many natural environments. The animal species in these environments suffer greatly when the water becomes toxic like this.

Invasive Species

Pollution is not always caused by chemicals. Sometimes, non-indigenous plant or animal species are inadvertently introduced to an area. This can result in big changes in the natural balance of life in an area.

As I mentioned previously, large levels of natural plants like algae can have devastating effects on aquatic environments. Invasive species can have big effects right down the food chain.

The Effects of Water Pollution

Many people do not worry about water pollution since it does not directly affect them. Some people even argue that water pollution is a necessary evil in the name of progress.

The fact is, water pollution devastates ecosystems which causes disruptions in the natural cycle of things.

Another problem is that it costs billions every year to combat. When there is an oil spill, people have to clean it up. Or when there is a need in the community, tax money has to be used to clean up the mess.

Unfortunately, the money usually goes where it’s needed most urgently and water pollution doesn’t often take effect until years down the line. There’s also the fact that national governments don’t always do what’s best for their people. Tax money is spent on the issues that will impress the most voters in the short term.



The clean-up costs for polluted groundwater are massive too. Sometimes the costs are so huge that a community will just choose to abandon a water source. Losing natural water supplies like this is devastating to the environment.

Groundwater pollution also leaks into other natural water systems like rivers and lakes. As this can happen so slowly, it becomes really difficult to pinpoint the source of pollution in the first place.

That brings up another concern.

Water pollution makes people sick. Polluted water can cause all sorts of deadly diseases such as cholera and hepatitis. Governments need to “clean” the water, and this costs a lot of money.

The bottom line is that water pollution is becoming a bigger problem.

Soon it will affect more than just a few coastal towns or countries without access to clean water. We lose natural water supplies almost daily due to pollution and rising seawater levels.

Combine this with the fact that the demand for water is getting more all the time due to the increasing population and we have a serious problem.

What Can We Do to Fight Water Pollution?

Now that we are aware of the situation, we need to do something about it. But what can be done to stop water pollution?

One of the biggest ways to stop it is through education. People know about water pollution, but they do not know how to fix it or how it affects them.

Water pollution is a mystery. It is something that we know is a threat, but since it does not directly affect most people, they are not moved to take action.

By taking steps to educate the public about water pollution, we can work together to make a change and fix the problem. Many countries have begun to add this into their school curriculum and many organizations make it their aim to educate the public about the problem.

teach letters

Another way to combat water pollution is by cutting off the biggest polluters. Many countries have gotten together to set up new laws to control waste management.

There are many strict rules that companies have to follow to get rid of their waste. Unfortunately, due to transboundary pollution, this means that all countries have to cooperate with these laws to prevent one area’s waste from polluting another area.

The UN and European Union have very strict water-protection laws to protect our oceans and prevent transboundary pollution.

Many countries have also begun to implement the ‘polluter pays principle’. Stricter laws have forced oil tankers to take out insurance in case of oil spills.

If the tanker spills, then the company has to pay. This principle means that companies are a lot more careful when transporting oil. This principle has also been applied in smaller ways.

For example, in most countries, you have to buy a plastic bag to pack your groceries now. Some countries impose strict fines if they catch you littering. Other countries also have monetary reward systems for recyclers. These are small changes but if we all make an effort they can have a bigger impact.

A Cleaner Future?

The earth is an amazing place. It has natural systems in place to take care of waste and carry it far away. In time, all water pollution will be cleaned away and it will be as if it was never damaged. That is what is supposed to happen.

Sadly, the earth does not get a chance to heal anymore. There is so much pollution that these natural processes are not getting a chance to work properly anymore.

Water pollution is a serious danger that threatens many balances that make life as we know it possible. It may even have far-reaching effects that touch areas thousands of miles away. But through education, preventative laws and a little conscientious effort, we can win the ongoing battle against this threat.

There are loads more articles like this at Find out how too much water can be dangerous here.

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About the Author James Smith

James is the chief water geek here at His mission is to empower the consumer and allow people to take control of their health. His passion for water health is contagious, hopefully unlike your tap water!

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