Water Pollution: Causes, Effects, and Solutions

Here's what you can do to protect the world's waterways

Water pollution
Polluted water is considered by many to be the world's biggest health risk. Getty Images

Our planet is comprised primarily of water. Aquatic ecosystems cover more than two-thirds of the Earth's surface. And all life on Earth as we know it relies on water to survive.

Yet water pollution is a very real threat to our survival. It is considered by most scholars and politicians the world's biggest health risk, threatening not only humans, but also myriad other plants and animals that rely on water to live. According to the World Wildlife Fund: 

"Pollution from toxic chemicals threatens life on this planet. Every ocean and every continent, from the tropics to the once-pristine polar regions, is contaminated."

So what is water pollution? What causes it and what effects is it having on the world's aquatic ecosystems? And most importantly—What can we do to fix it?

Water Pollution Definition

Water pollution occurs when a body of water becomes contaminated. The contamination could be caused by physical debris such as plastic water bottles or rubber tires, or it could be chemical such as the runoff that finds its way into waterways from factories, farms, cities, cars, sewage treatment facilities, and air pollution. Water pollution occurs any time that contaminants are discharged into aquatic ecosystems that do not have the capacity to absorb or remove them.

Water Sources

When we think about the causes of water pollution, we have to think about where it comes from. There are two different sources of water on our planet. First, there is surface water—that's the water that we see in oceans, rivers, lakes, and ponds. This water is home to many plant and animal species that rely not only on the quantity but also the quality of that water to survive.

No less important is groundwater—the water stored below the surface in the Earth's aquifers. This water source feeds our rivers and oceans and forms much of the world's supply of drinking water. 

Both of these water sources are critical to life on Earth. And both can become polluted in different ways. 

Surface Water Pollution Causes

Bodies of water can become polluted in a number of ways. Point source pollution refers to contaminants that enter a waterway via a single, identifiable source, such as a waste water treatment pipe or a factory chimney. Non-point source pollution is when the contamination is coming from many scattered locations. Examples of non-point source pollution include the nitrogen runoff from agricultural fields that leaches into rivers and streams, or oil from parking lots into city sewers.

Groundwater Pollution Causes

Groundwater can also be affected by point and non-point source pollution. A chemical spill can seep directly into the ground, polluting the water below. But more often than not, groundwater becomes polluted when non-point sources of contamination such as agricultural runoff or prescription medications find their way into the water within the Earth. 

How Does Water Pollution Affect The Environment?

If you do not live near water, you may not think that you are affected by pollution of the world's waters. But water pollution affects every single living thing on this planet. From the tiniest plant to the largest mammal and yes, even humans in between, we all rely on water to survive. The water from your tap may be filtered by a water treatment facility before it gets to you, but ultimately it comes from either surface or groundwater sources.

Fish that live in polluted waters become polluted themselves. Fishing is already restricted or prohibited in many of the world's waterways due to contaminants. When a waterway becomes polluted—either with trash or with toxins—it diminishes its capacity to support and sustain life.

Water Pollution: What Are The Solutions?

By its very nature, water is a very fluid thing. It flows throughout the world without regard for borders or boundaries, crossing state lines and country borders alike. That means that pollution caused in one part of the world could affect a community in another. This makes it difficult to impose any one set standard on the ways we use and protect the world's water.

There are a number of international laws that aim to prevent dangerous levels of water pollution. These include the 1982 UN Convention on the Law of the Sea and the 1978 MARPOL International Convention for the Prevention of Pollution from Ships. In the U.S., the 1972 Clean Water Act and the 1974 Safe Drinking Water Act were created to help protect both surface and ground water supplies.

How Can You Prevent Water Pollution?

The best things that you can do to prevent water pollution are to educate yourself about the world's water supply and support conservation projects both locally and around the world.

Learn about the choices that you make that affect the world water, from spilling gas at the station to spraying chemicals on your lawn and look for ways to reduce the number of chemicals you use each day. Sign up to help clean litter off of beaches or out of rivers and oceans. And support laws that make it harder for polluters to pollute—the Clean Water Act in particular has often come under political attack.

Water is the world's most vital resource. It belongs to all of us and it is up to everyone to do their part to protect it.