Knowledge Channel

The 8 Biggest Water Pollutants

Water is one of our most valuable resources and without it our existence would not be possible. However, ironically, we ourselves are the biggest polluters of this very precious asset. Discover the 8 biggest water pollutants and learn how they can contribute to your scarcity.


Oil is one of the biggest pollutants in the seas and is a highly toxic product. Contamination occurs on the high seas when there is a leak – and when such a problem occurs, it is very difficult to contain it. To avoid this harmful pollutant, it is important to have strict control and regulation of the companies that extract the oil.

Domestic sewage

When untreated, sewage water can cause serious damage to nature and our health, if dumped into rivers and springs. According to the IBGE, this is the biggest water pollutant in Brazil. Moreover, organic compounds are rich in microorganisms that can cause serious diseases. To avoid incorrect disposal, sewage must undergo adequate treatment or, when this is not possible, it must be directed to septic tanks or biodigesters.

Acid rain

Acid rain occurs when there is a reaction of gases resulting from the burning of fossil fuels with water vapor present in the air. Its contamination pollutes rivers and plantations, in addition to destroying soil biodiversity. This phenomenon can be avoided by reducing our carbon footprint, which can be done with some attitudes, such as using public transport and consuming products with low emission of toxic gases.


The liquid that flows from the dumps, formed by thousands of microorganisms, is extremely polluting. When garbage is disposed of in an inappropriate place, leachate can seep into the soil and contaminate groundwater. Selective collection and the correct disposal of waste in landfills that comply with sanitary requirements is essential for this to be avoided.


Pesticides used to combat pests in agriculture are extremely poisonous and are the second largest cause of river contamination in Brazil. Water polluted with pesticides directly harms aquatic fauna and flora, in addition to bringing risks to human health. To avoid this type of contamination, there must be regulations on the use of these products, in addition to greater incentives for organic and agroforestry agriculture.

Kitchen oil

Vegetable oils used in food, when discarded in water, favor the eutrophication of the aquatic environment, which is the proliferation of certain algae, causing a series of imbalances in rivers, seas and lakes. A single liter of oil can contaminate up to a million liters of water! To prevent this from happening, the oil must be disposed of at specialized collection points.

Solid waste

All garbage carried by the rains or improperly disposed of in rivers and seas is extremely harmful to nature. In addition to being a threat to aquatic fauna, garbage takes years to decompose in the environment – a single plastic bag takes 100 to 400 years to disintegrate. To reduce this type of pollution it is important to dispose of waste correctly.

Heavy metals

Improper disposal of batteries can be more harmful than you think. These products release toxic substances that not only pollute rivers and groundwater, but are also highly harmful to the lives of animals, plants and human beings. The disposal of this type of product must be done at specialized collection points, to be disposed of correctly.