Causes and Effects of Water Contamination

The first step to understanding the causes and effects of water contamination is to define the contaminants. However, this is not that easy to do. While the scientific term may be easily defined, some regulations offer particular lists of what is and isn’t considered a contaminant.

If you’re worried about the differentiation, you shouldn’t be. This article will settle things for you once and for all. Hopefully, you’ll have a better understanding of how water truly impacts every aspect of your life and why its quality is of the utmost importance.

After this article, you’ll be able to tell the difference between contamination and pollution. You’ll also be able to better comprehend why some contamination is bad and why some of it is good. But, before all of that, let’s start off with the basics and the answer to the most common question.

What is Water Contamination?

Water contamination is something that occurs when physical, chemical, biological, or radiological elements are present in water. This generally means that anything other than pure water can be considered contaminated water.

It should make no difference if the water contains harmful bacteria or beneficial nutrients. Anything extra that you can find in it, which can be determined through various tests, is a contaminant. Therefore, water contamination is the correct terminology to use even if there is no health risk associated with it.

Water Contamination vs. Water Pollution

Not many people know the difference so don’t beat yourself up over this. Because of the nature of the two words, contamination and pollution are often misused. Here’s a quick clarification that you will be able to remember.

Various types of water pollution occur as a direct result of heavy contamination. Other than pure water, all water is contaminated by something. Non-contaminated water is water that doesn’t have anything else in it besides the water molecules. Even salts and minerals are considered contaminants.

When does pollution occur? Pollution kicks in once the presence of contaminants rises to dangerous levels. Just take copper as an example. It’s common to find small quantities of copper in water and it can even be beneficial.

When the concentration of copper reaches health threatening levels it’s no longer considered a contaminant, but a pollutant. Thus, the term water pollution becomes appropriate.

Another good example is the Gulf of Mexico or BP Oil Spill. You can theoretically say that the water became contaminated with oil, but given the massive size of the spill it wouldn’t be appropriate. The BP Oil Spill resulted in the pollution of the water.

This is also a good example of a man-made and direct cause of water pollution, but more on this later as we explain the classifications.

Causes of Water Contamination

Now that you know that water contamination can lead to water pollution, it’s time to discuss some causes of water contamination. After all, some of the water pollution effects can have serious repercussions. Many water contaminants are similar, or at least they act similarly.

Water contaminants can fill up entire books of information. To make things easier for you, here’s a rundown of the most important ones and how they can be classified. Let’s start with nature’s contaminants.


It’s a common misconception that most water contaminants are manmade. This couldn’t be further from the truth.

Animal waste is one of the most common contaminants. Did you ever wonder why everyone recommends boiling water before drinking it from a river, lake, stream, or any other type of open body of water?

Heavy metals are also causes of water contamination and most of the time this happens naturally. Iron, copper, arsenic, even lead, are found in natural rock formations. Trace amounts of these heavy metals make their way into the water naturally.

Radioactive materials also occur in nature. You don’t have to drink water from under a nuclear power plant or a bomb disposal site to find that you’ve been exposed to radioactivity.

Take radon for instance. Radon gas can occur naturally, which means it can easily find its way into organic water sources.

Nitrates are also water contaminants. These are quite widespread in waters with large fish populations. This is because they are produced from aquatic wildlife waste.

One thing worth noting here is that natural contaminants very rarely lead to water pollution. Nature has a way of balancing itself out. If you take for instance the oil spills, the pollution usually happens as a result of human error or an engineering failure.

In contrast, natural oil water contamination happens all the time but it almost never reaches pollution levels.


Let’s talk about how you can contribute to water contamination. Things and substances made by human hands which can contaminate the water upon contact are called manmade contaminants.

There’s a lot of natural water contamination that you can observe. However, when it reaches your house, there’s a very high chance that the contamination is our fault.

Hazardous waste can find its way into fresh water sources in two ways. Either by rainfall or by seeping through layers of earth and making its way into groundwater sources.

Dumping of chemical waste from oil refineries and other industrial processes is also a form of hazardous waste. What’s even worse about this is that the effects may not occur until decades after the contamination.

If you’re like most people that live in places with harsh winters, you probably hold road salts in high regard. Did you know that they are also considered water contaminants?

These can affect the soil and surface water sources as easily as melted snow and ice. It’s not hard to see how quickly they can make their way into your well water or tap water.

Of course, the causes of water contamination can be further classified as direct and indirect sources. For example, direct sources are made up of spills and leaks.

  • Oil spills – These generally occur as a direct result of human error or mechanical failure.
  • Septic system leaks – More often than not the cause of septic system can be traced to degraded pipes. It can also happen as a result of direct damage during an earthquake or other seismic events.
  • Construction site runoff – Again, this is generally a matter of human error or disregard for regulations.
  • Chemical dumping – This is also an indirect cause. Since the effects may take place far away from the source or long after the act, it may be very hard to trace back to the point of origin.
  • Others include: landfills, agricultural sites, and factory dumping

Causes and Effects of Water Contamination

Sources of Water Contamination

Let’s talk a bit about some of the sources of water contamination. There’s a slight difference between cause and source. Let’s see if you can spot it.


Groundwater is a source of water contamination. Because contaminating factors or triggers such as spills and runoffs seep through the soil, groundwater becomes a source of water contamination.

Why is it important, you ask? As you may or may not have known, groundwater is where the fresh drinking water of most municipalities comes from. This is true for the entire world, not just third world countries.


Okay, so not everyone collects rainwater for use. Does that make it less dangerous? Not really.

Rainwater pollution is very dangerous as it can affect more than just the local fresh water supply. Rainfall makes its way into forests, streets, your backyard, and so on. Thus, it becomes a source of water contamination.

How does rainfall get contaminated? Well, you should know by now how rain is formed. As the hydrologic cycle dictates, surface water evaporates and becomes rainwater.

As you’ve guessed by know, if the surface water is contaminated or polluted, the resultant rainwater will retain those chemical profiles. Incidentally, this is what leads to the so-called acid rain.

What’s even worse? The contamination in one body of surface water can affect another, miles away from it. That’s because the contamination can be carried for miles (high up in the clouds) before rainfall drops.

Surface Water

You might think that contaminated surface water isn’t that dangerous. After all, open fresh water supplies are treated. But, remember the hydrologic cycle?

Not only can contaminated surface water impact wildlife on its own, but it can become even more dangerous when it evaporates, and the contaminated vapor moves with the wind to a new location.

Effects of Water Contamination

Everybody knows the effects in general but let’s break them down and describe in more detail.


It’s true that pollution tends to have a more dramatic impact on the environment. However, there are plenty of contaminants that slowly work their way into water. After all, what’s pollution without the initial contamination?

Here are some of the common water contaminants that have an impact on our environment.


Chemical buildups in water sources are not as uncommon as you think. When it comes to causes and effects of water contamination, chemicals play a major role. Once fresh water sources become contaminated with dangerous chemicals, the wildlife becomes endangered.

This is a common occurrence in rivers or lakes that are located near factories. It also happens when too much wastewater makes its way into fresh water. So how does this affect the environment?

It all starts with the fish. They take in the harmful chemicals and then pass them on to birds and mammals. This starts a dangerous cycle of animals eating other animals while contaminating each other and the area around them.

Toxic Runoff

Toxic runoff can affect plants in a most unpleasant way. Apart from killing fish, insects, and birds, the runoff from factories can easily make its way into agricultural sites. Thus, your crops can suffer.

Nutrient Poisoning

Nutrient poisoning is very dangerous as it is quite hard to spot. Unlike chemical spills, fish won’t necessarily die from nutrient poisoning. However, they will become contaminated and may very well pass the toxicity along to birds, insects, plants, and everything else that might end up on your dinner plate.


It should come as no surprise that one of the effects of water contamination is its negative impact on the economy. We all rely on drinking water, and in some parts of the world the need is even greater.

When the few remaining sources of fresh water become contaminated, there are more things to consider than just a general health hazard.


Many places rely heavily on tourism as a source of income. Just think of how many people worldwide visit lakes, natural springs, rivers, and other natural or manmade water sources.

Any type of water contamination that affects the quality of the water and the surrounding wildlife can put a halt to the area’s tourist activity. Whether it’s a lake with high levels of lead or high concentrations of bacteria and parasites, neither is attractive for tourists.

While you personally may not feel the effects of this if you live in a big city, those that live in small mountain towns or around water parks certainly will.

Real Estate

Would you move to a neighborhood known to have issues with water contamination or other types of water pollution? That’s highly doubtful.

There are a couple of things that happen when water contamination becomes highly publicized. The first instinct of most residents in that area is to move away. Very few tend to return.

New residents aren’t likely to come at least until the problem is fixed. The bad news is that not everything can be fixed.

Last but not least, there is such a thing as bad publicity. For some health-conscious people, it’s often enough to associate water contamination with a residential area. Even if everything is cleaned up and safety precautions have been taken, there’s no guarantee that new folks will take the chance of moving there.

Because of this, people that own real estate in the affected region would have a hard time getting their money back and starting over. Big companies and investment firms also take big hits under these circumstances as millions can be lost in a matter of minutes.


Any discussion about the causes and effects of water contamination would not be complete without talking about the health impact, or more specifically the bacteria. Although not all bacteria in water are harmful, there are plenty of them that can cause serious damage.

Think hepatitis, E. coli, cholera, dysentery. Sound familiar? While these types of situations don’t happen often in the Western world, they’re not that far of a stretch.

Contaminated water can lead to more than just bad-tasting tap water and ruined sauces or broths. It can put you in the hospital fast or slowly. You can be the judge of which one is worse.

Parasites tend to lay eggs inside the body. This means that by drinking contaminated water you can set yourself up for a trip to the hospital, not immediately but perhaps after weeks or months. When the symptoms build up slowly like this, it can also be hard to diagnose.

Skin irritation can also occur on account of contaminated water. Heavy metals are known to cause skin rashes. If this happens to you a lot while showering, it may be time to check your water source. You should also change your pool water or your favorite swimming spot if rashes are common.

This is one video that really opened my eyes. Often the contaminants in our water have no foul odor or horrible taste so they go unnoticed, but it is slowly poisoning our bodies.

Types of Water Pollution

So we’ve explained how water contamination and water pollution are different. If you’re still following, then it shouldn’t be hard to see how the causes and effects of water contamination can lead to all types of water pollution if left unchecked.

The types of water pollution can also be classified as direct or indirect and as natural or manmade. This is very similar to the types of contamination because the two of them often go hand in hand.

Here’s a quick refresher of the types and sources of water pollution:

  • Surface water pollution – When surface water is heavily contaminated, pollution becomes an issue. As water evaporates, the pollution can be easily carried across vast regions. It can also lead to the death of wildlife in the area, such as plants, birds, animals, fish, etc
  • Nutrient pollution – Pollution as a result of nutrients is usually manmade. Although there’s plenty of natural nutrient contamination, it is generally the result of wastewater and excessive use of fertilizers that trigger nutrient pollution.This mostly affects wildlife as it stimulates the production of algae in the water. This causes oxygen depletion and can even cause filters to clog if the water source is used by humans.
  • Ground water pollution – Pesticides, chemicals, and many other harmful contaminants that we pour everyday into the soil can pollute groundwater sources. This is something that may not be evident until generations later.
  • Rainwater pollution – Polluted surface water becomes rainwater. You get the drift.
  • Microbiological pollution – Microbiological pollution can cause serious illnesses. If the water is left untreated or consumed untreated, the microbial contaminants can reproduce to dangerous levels.This is common in third world countries but also in poor communities that rely on low quality water sources. Viruses, bacteria, and protozoa are the common culprits.
  • Chemical water pollution – Chemical water pollution is generally a result of manmade spills, leaks, or pure carelessness. Everything that we use to tend to our plants, kill bugs, and for various purposes can pollute water supplies.The dumping of heavy metal-rich waste and other chemical waste can contaminate both surface and groundwater sources. In the case of severe pollution, the results could be as devastating as rendering a land area or body of water inhospitable to wildlife or aquatic life.

Who is Affected by Water Contamination?

Discussing the causes and effects of water contamination and understanding them is important for a couple of reasons. First of all, you must understand that water contamination and pollution affects every living organism on the planet more or less.

It probably affects humans more than anyone else. Why? Because although we are complex organisms, we are also quite fragile. On top of that, whenever our food chain takes a hit, we also take a hit as we have to readjust.

Of course, you may be thinking now, how can we stop this? This is one of those things that are easier said than done. The truth is, whether you want to accept it or not, human society is highly dependent on substances and industries that have a negative impact on the environment.

Agriculture perhaps suffers the most. While some of the pesticides and chemicals are necessary to ensure optimum crop growth and steady production, they are also water contaminants.

Their overuse eventually leads to water pollution. Luckily so far, this type of pollution has only been seen on a small scale and in isolated locations. On the other hand, chemical runoffs, waste dumping, and oil spills are known to cause serious environmental imbalances.

How to Tell if Your Water is Safe

This is where things can get tricky. Immediately after you find out what are the causes of water pollution, a new question arises. How can you know if your water is safe to drink or bathe in?

Luckily, in most parts of the world, whenever pollution is a cause for concern, various alerts are put out by the proper authorities or non-profit organizations that monitor these situations.

There are various experts around the world that can list the major types of water pollutants in their sleep.

Why is that important? Because they always know what to look for and where to look for it. So, in case of an outbreak, oil spill, radioactive leak, you should get notified in time.

Of course, most problems arise when water contamination has not reached dangerous levels yet to be noticed. In those scenarios you may need to take matters into your own hands.

There are various pH tests and bacterial tests that you can carry out. Either with your own equipment, if you have a background in chemistry, or by taking water samples and sending them to specialized testing facilities.

Remember that most contaminants are invisible to the naked eye. Short of rust and dust turning your water into mud, in most cases you won’t be able to tell if your water is fine just by looking at it.

Even if there aren’t any reports of low water quality in your area, sending away a sample to be checked out from time to time isn’t a bad idea. This is especially important if you rely on well water. Even if you already have a water filter system in place, it’s recommended that you test well water at least once a year.

Since your well water doesn’t go through a treatment facility, it’s hard to monitor what contaminants might have made their way into the water after a rain or after the snow melts.

You don’t have to drink tap water to know something is wrong with it or to feel the need to test it. If you use it for cooking or washing, that’s enough to warrant a test. A slight acidic taste or too much steam in the shower could indicate that something is wrong with your water supply.

Besides, there are plenty of contaminants that could enter your water supply when the water is in transit. In fact, there are more cases of contamination and pollution happening in transit than in a treatment facility.

A leak in the sewage system can eventually lead to contaminants entering your water supply. Heavy metal poisoning and slow-developing illnesses are also among the causes and effects of water contamination and pollution.

Many cities still have very old pipe systems that are connected to the newer ones. This is one of the main reasons why lead is often found in water.

The advanced filtration units and alert systems at treatment plants can quickly spot a problem and shut down the supply. However, if something happens along the way, there’s not much your water company can do for you.

How to Clean Up Your Water

To remove most of the contaminants that enter your main water supply, you will need a water filtration unit. Because there are so many causes and effects of water contamination, the quality and installation point of your filter is very important.

If you’re only concerned about drinking water, a point-of-use or POU system that connects to a faucet is the way to go. These are generally easy to install and don’t cost too much. The downside is that some of them can slow down the water flow rate at that faucet.

If you want to have clean water all around your house, drinking water, washing water, boiler water, and even gardening water, then you will need a point-of–entry or POE filter system. These filters are installed at the main intake pipe. The advantage is that they treat your water before it branches out to different faucets in your home.

Types of Water Filters for Different Contaminants

Each water filter has a different purpose. Not only that, but some of them are dependent on other filters to soften up the water upstream.

Carbon filters

These are the most popular water filters. They help reduce the levels of lead, pesticides, chlorine, radon, as well as some parasites and bacteria. Carbon filters are also quite cheap, so you can see why it’s so common.

Reverse-osmosis filters

These filters can be quite pricey. That being said, they are far more effective than carbon filters. They help remove chemicals, heavy metals, and other particles that carbon filters aren’t equipped to handle (usually because they are too microscopic).

It’s worth mentioning that for a reverse-osmosis filter to work properly, you’ll need to have a carbon filter or more before it. This is to remove larger particles that can damage the reverse-osmosis membrane if they’re removed beforehand.

UV filters

Although they are regarded as filters, UV filters are lamps that bombard the water with UV ray to disinfect the water. They are efficient at disposing of bacteria and other microorganisms.

Alternative: Distillation

There’s also an alternative to filtration. A water distillation system can also be used to deal with a variety of contaminants. Distillation can remove heavy metals, bacteria, chemicals, viruses, and fluoride from your water.

Keep in mind that this only works on contaminants that don’t have a higher boiling point than water. Distillation systems are also quite expensive and require more maintenance than filtration units.

Regardless of what system you choose to go with, remember that the more filters you have the lower the flow rate will be. Not only that, but some of these units can also be quite expensive to run.

Considering that even the most advanced commercial filters can only remove up to 99.9% of contaminants, you might not want to overdo it.

Test your water, see what’s wrong with it and address that issue in particular. For example, radioactive water and chemical-laced municipal water are unheard of in some parts in the world, so you might not want to blindly tackle a problem that doesn’t exist.

There’s nothing wrong with preparing for the worst, but not everyone can afford to do that. On the other hand, investing in a water filter system (even a high-end one) is likely to be more cost-effective in the long run than buying bottled water.


While it’s true that you couldn’t survive without water, it’s also true that drinking and cooking with pure uncontaminated water every day may not be possible. Besides, some contaminants are actually useful in certain doses: these include minerals, nutrients, etc.

However, understanding the need to treat your water is important. Removing as much of the harmful contaminants as you can is essential for your health and the environment. The causes and effects of water contamination are varied and hard to monitor entirely.

Be that as it may, it’s good to know the differences and similarities between them so that one can take the appropriate precautions. After all, too much contamination often leads to pollution and potentially catastrophic environmental disasters.

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