The Causes and Effects of Groundwater Contamination

Do you know what groundwater is?

Have you heard this term thrown around here and there, but find yourself more and more curious about just what it means and why it’s important?

Do you find yourself wishing you could get more involved in learning about how to keep the environment around you healthy and protected?

If you’re interested in learning more about groundwater, this article is here to help. Groundwater is a valuable part of the water supply around the world, and in the United States as well as in developing countries this type of water continues to be heavily relied upon by individuals, industries, and more.

Unfortunately, groundwater also becomes contaminated easily, and the more frequently human beings interact with sources of groundwater, the more likely they are to become polluted.

In this article, you’ll learn more about what groundwater is and why it’s important. You’ll also find out about the causes of groundwater contamination, as well as changes that can be made to cut back on these pollutants. After learning how groundwater pollution can be caused by many different factors, you’ll be provided with a list of possible outcomes of this type of water contamination.

By the time you’ve finished reading, you’ll be able to identify the causes of groundwater pollution as well as the effects. You’ll be much more informed and able to make sound, environmentally-safe decisions in your life, and you’ll even be able to share this information with others around you. In no time you can easily become an advocate for clean water in your community.

Now it’s time to get started.

What is Groundwater?

In order to understand the causes of underground water pollution and the effects this can have on just about every aspect of life around you, it is important to first know what groundwater is and how it differs from surface water. To begin with, surface water is pretty much just what it sounds like: any water you can see on the surface of the ground around you. If you see a pond, a lake, a stream or even a puddle, that water can be classified as surface water. Keeping surface water clean is very important as well, but groundwater often goes unnoticed by the general population, and sometimes it flies under the radar for so long that it becomes seriously polluted without anyone noticing until it’s much too late.

underground water pollution

When water is found beneath the surface of the land, that water is known as groundwater. When rainwater falls, some of that water gets absorbed into lakes, streams, and ponds, and some of it is used by plants before it has a chance to go anywhere else. Other amounts of water evaporate instead of going anywhere. But the remaining water from rainfall has to go somewhere, and so it seeps into the ground to become groundwater.

Much of the water on Earth is found in the oceans, and some of it is still found frozen in glaciers. However, the remaining water—the water that is usable—is almost all made up of groundwater. A huge amount of non-ocean and non-glacier water comes from groundwater, although many people don’t realize this. It makes up more of the water we, as humans, come into contact with than does surface water. Read on to find out why this is important.

Why is Groundwater Important?

Now that you’ve learned a little bit about what groundwater is, it’s time to find out why it’s so important. You might feel as though water that can’t be seen on the surface of the land probably isn’t that important, especially because the chances of humans interacting with it are much lower than they are for ponds, lakes, and streams. However, this is not quite accurate. Actually, groundwater is incredibly important, and the sooner people start to realize this, the faster they’ll begin caring for it and keeping it as clean as possible. Below are a few facts to help you understand more about the importance of groundwater.

  • Most of our drinking water in the United States comes from groundwater. In rural parts of the country, up to 99% of the water used for drinking is sourced from groundwater. Although this number is smaller in cities and more built-up areas, the total amount of drinking water in the United States that comes from groundwater sources is still 51%. This means that just over half of the water we drink comes from groundwater, which in turn means that if this water gets contaminated, we will have fewer clean drinking water sources throughout the country.
  • Most of the water used in agriculture in the United States comes from groundwater. Around the country, 64% of the water used in agricultural processes comes from groundwater sources. Once again, this means that issues with the groundwater can significantly impact human life, this time by cutting back on healthy and successful crop growth. As more and more farmers rely on groundwater to grow their crops, the importance of keeping this water source clean grows.
  • Surface water cannot recharge without groundwater. It’s very important to the environment and the whole planet to replenish wetlands, swamps, lakes, and rivers after periods of drought. When groundwater is present, this water can be used as a source of refill and recharge for these important ecosystems. However, when groundwater is contaminated or not present at all, these parts of the environment suffer significantly. This can have major impacts around the world.
  • Where surface water isn’t present, groundwater often still is. There are many parts of the United States as well as the world that rely heavily on groundwater to provide drinking water as well as water for other uses, simply because there isn’t a lot of surface water present. This is especially true in dry parts of the country, such as the western U.S. In other countries where clean drinking water is a major source of crises, groundwater is a crucial part of providing people with something safe to drink.
  • Groundwater doesn’t often have to be treated much. When it isn’t already contaminated, groundwater is usually much cleaner than surface water, and it requires far fewer harsh chemical treatments to make it safe enough for human consumption. Many contaminants that come from nature are also removed by nature as the water passes through rocks and sand that serve as filtration.

Causes of Groundwater Contamination

cause and effect of groundwater

Now that you’ve learned about what groundwater is and why it’s important, you might be wondering, “What are some sources of groundwater contamination that I can look for?” It’s always a good idea to be able to recognize what causes groundwater pollution so you can help step up and make a difference when you see it in your area. When it comes to this type of pollution, every source can be grouped into one of four categories: direct, indirect, manmade, and natural. Although natural sources of pollution often can’t be changed much, there is always something you can do about other sources.

1. Direct

When learning about what causes groundwater contamination, you should first start with direct contaminants, as these are the ones you’re more likely to come into contact with.

  • Hazardous waste. When hazardous waste is disposed of or dumped incorrectly, the chances of it spilling and leaching into soil and water are great. It’s very likely for this type of spill to occur and go completely unnoticed. Unfortunately, this is also true of more widely recognized hazardous waste spills, but there’s very little that can be done about it. Once a spill occurs, it can almost never be removed from groundwater.
  • Landfills. Landfills are another direct cause of pollution in groundwater. The longer a landfill remains full of waste, the more the toxins from that waste seep into the soil below and around the landfill. This leads to groundwater contamination almost immediately. When landfills are very large, the amount of groundwater polluted by them is significant.

2. Indirect

But what are some sources of groundwater pollution that are less direct?

  • Atmospheric pollutants. Sometimes, when surface water in the area becomes polluted, this can lead to those pollutants evaporating into atmospheric air and water. In turn, polluted air can drift into areas where humans are more present, and polluted rain can fall as acid rain. This damages the environment and can also cause serious health risks for people in the area, too.
  • Petroleum fuels. Diesel and gasoline are well-known indirect causes of groundwater pollution. In some instances, these fuels, when kept in underground storage, can leak significantly and seep into the ground around them, leading to groundwater contamination. Most of the time, however, the use of these fuels pollutes the atmosphere and leads to indirect atmospheric pollution of groundwater through the rain.

3. Man-made

It’s no secret that human beings are a huge polluter of groundwater. These are just some of the manmade ways groundwater gets contaminated.

  • Septic systems. In much of the United States, city-based water and sewage are unavailable, especially in very rural areas. When this is true, septic systems are usually the go-to solution to provide running water and plumbing to people in these regions. Septic systems are very common in the U.S., and in most cases, they aren’t supposed to cause any groundwater contamination at all. Unfortunately, sometimes they are installed incorrectly or become damaged over time without regular maintenance. This causes human waste to leach into the surrounding soil, which in turn causes a lot of pollution very fast.
  • Chemicals. Road salts, solvents, and chemicals used on roads, in lawns, and around the home are some of the leading manmade causes of groundwater pollution. When these products are used on land surfaces or homes, they are easily washed away by natural rainfall. From there, since there’s nowhere else for them to go, they seep into the soil and reach the groundwater quickly. When humans and animals then drink this water, they are ingesting these chemicals, which can cause major health problems very fast. Also, when groundwater that has been affected by these chemicals is then used in agriculture or industry, it is unable to provide the proper nutrients and hydration required to get the job done.
  • Pesticide. Much like chemicals and other man-made solutions, pesticide is prone to washing into the soil after heavy rainfalls, especially when it is used frequently by farmers and other members of the agricultural industry. The chemicals involved in pesticides are very dangerous for both human and animal consumption, and when they reach groundwater, they can almost never be completely removed.

4. Natural

Learning about groundwater contamination involves finding out more about natural contaminants like animal waste, which is not a major source of groundwater pollution.

  • Animal waste. Although animal waste is usually more of a problem for surface water contamination and often stays out of groundwater, this isn’t always the case. In some situations, especially where animal life is very prevalent, urine and feces left behind by animals seep into the ground and cause some pollution to the groundwater there. When this happens, the type of pollution caused by these contaminants is usually easy to remove by water treatment facilities. However, it does make groundwater unsafe to drink without treatment.
  • Arsenic. Sometimes, arsenic is naturally present in rocks. When groundwater passes through or sits in these rocks for too long, it can cause arsenic to build up in the groundwater to levels that are capable of poisining animals or people who drink it. This is rare, but it does occur, especially in areas where mining has been present and might have exposed these types of rocks. Again, regular water treatment can usually remove arsenic from groundwater.
  • Radon. Radon gas is also another natural pollutant that can nevertheless cause serious problems. If a human being or an animal consumes water that has been polluted with radon gas, the results can be potentially fatal. Like the other types of natural pollution in groundwater, radon gas can sometimes be removed by treatment. However, it’s very important not to drink water that could have potentially been polluted with radon until it has been thoroughly tested by professionals.

Effects of Groundwater Contamination

 type of contamination

Understanding the common sources of groundwater pollution is always a good first step, but from there, you should realize what the effects on your health and the world around you can potentially be when this type of contamination is present. Now that you can recognize what are possible sources of groundwater contamination, read on to find out more about what this means for you and your community.

5. Health

Health effects are some of the greatest risks associated with groundwater pollution. Here are just a few you should be concerned with.

  • Hepatitis. In areas where septic systems have not been installed or kept up correctly, groundwater may become infected with hepatitis due to human waste present in the water supply. Hepatitis is a very serious condition that causes irreversible damage to the liver.
  • Dysentery. Much like hepatitis, dysentery can be caused by drinking water where waste is present—either human or animal in nature. Once again, when septic systems don’t operate correctly, the chance for dysentery is much higher, much like with hepatitis. Dysentery causes infection throughout the intestine and digestive system, and can also cause diarrhea so severe it can lead to dehydration and even death when not treated properly.
  • Poisoning. When wells are not dug or placed correctly, poisons from both nature and from human use of pesticides and solvents can leach into the well water and poison the water supply. When humans then drink this water, they can become very ill very fast from exposure to chemicals and other pollutants that are unsafe for ingestion. This can also make animals sick as well, including animals that might be watered from a well on a farm.

6. Economy

When groundwater becomes contaminated, the economy can also easily suffer. Check out this list of potential economic problems associated with groundwater pollution.

  • Depreciating value of land. When groundwater becomes more contaminated in a given area, that area becomes less capable of sustaining human, animal, and plant life. If the area is known for its natural beauty and that nature begins to suffer the effects of pollution, the chances of people wanting to live there decrease even more. Although it might not be an immediate result of groundwater pollution, the depreciation of land value is definitely a potential side effect.
  • Less stable industry. Many industries rely on groundwater to help produce their products and keep their factories running smoothly. Since the pH and quality of groundwater from a given area rarely changes, it becomes a vital part of many industries that rely on water they don’t have to constantly test. However, when groundwater becomes polluted, this convenience is stripped away, and the industries are less capable of stable production. This, in turn, can affect the economy in any given area as industries are forced to move.

7. Environment

Last but certainly not least, the environment can be seriously altered when groundwater is polluted. Here are just some of the ways in which this occurs.

  • Nutrient pollution. Groundwater pollution can cause certain types of nutrients that are necessary in small amounts to become far too abundant to sustain normal life in a given ecosystem. Fish might start dying off quickly because they are no longer able to process the water in their water supplies, and other animals might become sick from too much of certain types of nutrients in the water they drink. Plants might not be able to absorb water as easily, and the entire ecosystem will suffer.
  • Toxic water in ecosystems. When groundwater that supplies lakes, rivers, streams, ponds, and swamps becomes contaminated, this slowly leads to more and more contamination of the surface water as well. When this happens, fish, birds, animals and plants that live in the area become sick and die off quickly. This is a huge factor in the destruction of the wetlands, which rely heavily on groundwater to recharge their lakes and ponds after drought periods. In turn, people who use this land for hunting, fishing, and even for their own sources of clean water are affected by this type of pollution.


You’ve come a long way I learning about the major sources of groundwater contamination. Now you know a lot more about what groundwater is and how it differs from surface water, and you also know how to recognize the importance of groundwater in your life as well as the lives of those around you. You understand the effects of groundwater pollution on environment resources, and you’ve answered important questions such as which gas is a source of natural groundwater pollution and which types of direct pollution you should be most concerned with. Of course, you’ve also learned more about why stopping this type of pollution before it gets too out of hand is very necessary. You have learned that the sources of groundwater contamination include both natural and manmade causes and that this means there’s always something you can do to help.

The more you study and learn about groundwater pollution, the more you can discover ways to make a difference in your community. Whether you choose to get involved with a local non-profit organization trying to make some changes or you just want to get out there and hand out flyers of information to educate the people around you, there’s always something you can do. If you’re a more hands-on individual, you might even want to get a little dirty cleaning up the groundwater sources in your area.

However you choose to get involved, now that you know more about groundwater, you can find the right way to make some changes on your own. You’re just a few steps away from becoming more environmentally-minded, and the more you educate yourself on this issue the better off you and the world around you can be. Don’t be afraid to make some changes in your home to improve the quality of the groundwater in your area. You might be surprised at just how easy it is!