7 Natural Causes of Water Pollution

You and I need good water to survive. Plants and animals need good water to survive and the Earth needs water to survive. It is so important to biodiversity that if they are fed polluted water, life begins to change. Natural life is likely to perish without good water.

There are two main sources of water pollution: human causes of water pollution and natural causes of water pollution.

The human population is increasing rapidly and their activities are affecting the quality of water on the earth. Human-induced causes of water pollution are is the most discussed cause of water pollution over natural causes of water pollution.

This topic is so prevalent in the environmental sphere that people are now curious and asking search engines – What are the natural causes of water pollution?

After some deep study, I collated 7 natural causes of water pollution. I believe that this article will help you further in your research, serving as the knowledge you can use as a foundation for the study.

What Are Natural Water Pollutants

Natural Water Pollutants are contaminants that are introduced into water by natural events thereby polluting the water. Some Natural Water Pollutants are contaminants such as arsenic, natural radionuclides, radon, and uranium.

7 Natural Causes of Water Pollution

  • Volcanic Eruptions
  • Windblown Dust
  • Acid Rain
  • Algae Blooms
  • Plants and Animal Waste
  • Flood
  • Earthquake

1. Volcanic Eruptions

7 natural causes of water pollution
Source: Carbon Brief

The first factor on my list of natural causes of water pollution is volcanic eruptions. Volcanic eruptions are one of the main natural causes of water pollution because when volcanic eruptions happen, they spew out not just lava, gasses, and ash.

When ash falls on natural waters, it causes turbidity, which is the ash suspended in the water. If the finer particles remain suspended in the water, they usually last from a few hours to a few days unless. An exception is when the ash fall occurs for a prolonged period. These ashes can travel a great distance polluting large bodies of water.

Hazardous disruptions in the water chemistry are rare. They usually render the water temporarily unsuitable for drinking.

The 1953 Mount Spurr volcanic eruption resulted in an ash fall of 3 mm-6 mm in Anchorage. This caused the turbidity of the public water supply to rise from 5 ppm to 290 ppm. It lasted for 6 days.

2. Windblown Dust

Can dust pollute water? In other words, is it one of the natural causes of water pollution?

Wind-blown debris and dust can pollute water when they are introduced into the water.

Wind-blown dust can carry sediment (e.g., silt) into water bodies. Suspended sediment or suspensions on the water’s surface interferes with the penetration of sunlight into the wat. In turn, this naturally upsets the ecological balance of the water.

Wind-blown dust can also disrupt the reproductive cycles of fish and other marine life. Additionally, when the sediments sink or settle out of suspension, these water pollutants can smother bottom-dwelling organisms in the water.

3. Acid Rain

7 natural causes of water pollution
source: NPR

Acid rain is one of the consequences of air pollution. Acid rain, in turn, is one of the natural causes of water pollution.

Gases produced from the burning of fuels by human activities react with the oxygen and the water vapor in the air. These become acids that fall back onto the earth’s surface as rain.

As acid rain flows through the soil after rainfall, the acidic rainwater leaches aluminum from clay particles and then all of them flows into streams, rivers, oceans, and lakes polluting the water.

The more acid that is introduced to the ecosystem, the more aluminum is released. The amount of aluminum that is released is directly dependent on the amount of acid that was released unto the Earth.

This alters the chemical composition of the water. The water becomes harmful to the aquatic ecosystem to survive and causes water pollution.

Acid rain also causes the corrosion of water pipes. The acid causes the leaching of heavy metals such as iron, lead, and copper which are introduced into drinking water.

Acid rain harms and kills fish in the water, affects the fish population in a water body, makes an entire fish species extinct from a waterbody, causes an imbalance in biodiversity, and decreases biodiversity.

Acid rain causes widespread acidification of water through direct acid rainfall into the water and acid runoffs. Acid runoffs have been tested to possess twice as much acidification as the rain itself.

In summary, the effects of acid rain are severe.

4. Algae Blooms

An algae bloom is one of the most popular causes of water pollution. Algae is one of the best Bioindicators (used to identify the quality and effects of pollution in the ecosystem and how long it may persist).

This is because their response to environmental pollution is quick, they are usually in large quantities in a location, and they are easily spotted amongst others.

Algae are involved in Water Pollution in many ways. Significant growth in the algal species in water affects the quality of water. Excess nitrates and phosphates in water cause algae blooms (a rapid growth sometimes causing unusually dense).

The algae in Water Pollution can be toxic to humans, animals, and fish who consume the polluted water in these ways:

  • Algae play an important role in the food chain of aquatic life. If the number of algae is altered, it will affect the organisms in the food chain of fish is included in it.
  • Algae are known to cause the taste and odor in water, (e.g., the Chrysophyta and Euglenophyta). This aquatic weed depletes the oxygen content of water bodies.
  • When the algae die, oxygen dissolved in the water declines because microorganisms use oxygen to digest algae during the process of decomposition.
  • It causes eutrophication.

On the coast of southwest Florida, harmful algal blooms have existed for over 100 years. These algal blooms cause species of fish, turtles, dolphins, and shrimp to die and cause harmful effects on humans who swim in the water.

5. Plants and Animal Waste

The animal waste that comes out from animals adds to Water Pollution. Dead plants in the water cause Water Pollution too. Feces and urine of birds and mammals are also significant contributors to water pollution.

This water pollution contaminates the water used for various purposes by humans, for irrigation of crops. The risk to human health is also much. Direct exposure of humans to this animal waste in the water can lead to health hazards.

The secretion of a large quantity of animal waste on the land can be washed by rainwater into the water as runoff water. Then, there is a large quantity of water degradation.

There is also the growth of microbes (e.g., bacteria and fungi) on dead and decaying plant and animal waste matter present in the body of water. 

6. Flood

7 natural causes of water pollution
Middle East Institute

Flood is one of the major natural causes of Water Pollution.

Water moving with a high momentum causes destruction along the way and carries a lot of sediments and other materials, and deposits them in waters such as rivers, ponds, lakes, and oceans polluting them.

These flooded particles that are deposited on the surface waters cause the pollution of water. Floods in their destructive movements pick up plant fertilizers, bodies, and other kinds of debris.

Flood also causes a huge loss in both lives of water bodies polluting the water further.

Flood adds Mud and sludge to water bodies due to the heavy currents and their diversions. The contaminant that flows along with the floodwater is in very high volume because it has coursed over many landscapes.

Erosion also dislodges fine particles from the rocks which flow with the water. As they flow with the water current, they are continuously eroded by the current of the water because water is a solvent. This causes some component minerals of the rock to dissolve into the water causing the water to get polluted.

There is a loss of drinking water and health hazards.

Fun fact: Did you know that flooding has positive effects on the environment?

7. Earthquake

How does an earthquake cause water pollution?

When an earthquake happens, the earthquakes destroyed buildings, and gasses from destroyed gas lines, debris, sewage, landfills, properties, plant fertilizers, bodies, chemical plants, sediments, and silts from construction sites are flushed into the waters thereby polluting them.

The water becomes disturbed and particles resting out of suspension in the sea bed are troubled.

These earthquakes can introduce soil and particles laden with carbon, nitrogen, phosphorus, and minerals producing nutrient-rich water which can cause algae and phytoplankton to bloom and create hypoxic conditions, starting an inevitable process of Water Pollution.

The well water might become turbid as a result of shaking. The shaking dislodges loose sediment cracks in the rocks that supply water to the well. However, this is usually temporary, lasting just a few hours or days.

The influx of sediments from the surrounding area can impact the water quality for surface and groundwater systems. Particles within the sediment may leach nitrates and arsenic compounds into good sources polluting good water.

There may be an additional risk of bacterial contamination in raw water supplies.

There are ways to deal with the aftermath of the earthquake:

  • Inspect wells for damage that has been caused by liquefaction.
  • Control leaks.
  • Conduct water quality sampling/analysis

There are many more impacts of earthquakes on the environment.


These are the natural causes of water pollution explained. Here are 7 of them: Volcanic Eruptions, Windblown Dust, Acid Rain, Algae Blooms, Plant and Animal Waste, Floods, and earthquakes. These causes combines with human factors create the most polluted rivers in the world. We should all seek ways to prevent water pollution.

What are some natural pollutants of water

  • parasites
  • Fertilizers
  • Pesticides
  •  Manganese
  • Uranium
  • Radon
  • Lithium
  • Bacteria
  • viruses
  • Cesium
  • Pharmaceutical products
  • Nitrates
  • Phosphates Plastics
  • Fecal waste
  • Radioactive substances.


Precious Okafor is a digital marketer and online entrepreneur that got into the online space in 2017 and since then have developed skills in content creation, copywriting and online marketing. He is also a Green activist and hence his role in publishing articles for EnvironmentGo

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