Water Pollution: Understanding The Root Causes

Water pollution is caused by a variety of factors, including human activities such as industrial waste, agricultural runoff, oil spills, and domestic sewage. It occurs when harmful substances are released into bodies of water, making it unsafe for human use and disrupting aquatic ecosystems. Water pollution has severe health, environmental, and economic impacts, and it is a pressing issue that affects both wealthy and developing nations. With the increasing global demand for freshwater, it is crucial to address the causes of water pollution and implement measures to protect this valuable resource.

Industrial waste

The waste produced by these industries contains toxic chemicals that can make water unsafe for human consumption. These chemicals can also cause changes in the temperature of freshwater systems, making them dangerous for marine life. Industrial waste can also create "dead zones", which are areas of water with such low oxygen levels that marine life cannot survive in them.

The types of industrial waste and the level of treatment required depend on the type of industry. For example, the food and beverage processing industries, clothing manufacturers, and carmakers all produce industrial wastewater. Wastewater from these industries can contain organic matter, metals, and other pollutants that must be removed before the water can be safely discharged back into the environment.

Some industries, such as petroleum refineries, chemical and petrochemical plants, and fossil fuel power stations, produce wastewater with significant levels of metals, including lead, mercury, cadmium, and chromium, as well as arsenic, selenium, and nitrogen compounds. These industries often have their own specialized facilities to treat their wastewater so that it complies with regulations regarding the disposal of wastewater into sewers or natural water bodies.

The escalating population has led to increased industrialization and, consequently, more industrial waste. This waste not only pollutes water but also air and soil, causing major environmental damage.

Sewage and wastewater treatment

Sewage Treatment

Sewage treatment is a type of wastewater treatment that focuses on treating sewage, which includes wastewater from households, businesses, and sometimes pre-treated industrial wastewater. The primary goal of sewage treatment is to remove contaminants and produce an effluent that can be safely discharged into the environment or reused. Sewage treatment can be centralized or decentralized. Centralized systems involve a network of pipes and pump stations that convey sewage to a municipal treatment plant. On the other hand, decentralized systems treat sewage closer to its source, such as through on-site treatment systems or septic tanks.

Wastewater Treatment

Wastewater treatment aims to reduce pollutants in wastewater to levels that nature can handle. Wastewater includes used water from various sources, such as homes, industries, and businesses. It can contain human waste, food scraps, oils, soaps, chemicals, and pharmaceutical products. Wastewater treatment typically involves primary and secondary treatment stages, with advanced treatment incorporating a tertiary stage for further polishing and nutrient removal. Primary treatment removes about 60% of suspended solids and involves aerating the wastewater to restore oxygen. Secondary treatment removes more than 90% of suspended solids.

Environmental and Health Impact

Water pollution has severe environmental and health consequences. It can destroy marine life and ecosystems, reduce oxygen levels, and create "dead zones" where marine life cannot survive. Additionally, waterborne pathogens, including bacteria and viruses from human and animal waste, can cause diseases such as cholera, giardia, and typhoid. According to the United Nations, water pollution causes more deaths annually than all forms of violence, including war.

Economic Impact

Water pollution also impacts sectors such as commercial fishing, recreational businesses, tourism, and property values, which rely on clean water. The treatment of polluted water increases costs, leading to higher drinking water prices. Additionally, the release of untreated sewage and wastewater can pose a serious threat to public health and the environment, as seen in combined sewer overflow events in some cities.

Oil spills and leaks

Furthermore, oil spills and leaks can have economic impacts. Polluted drinking water can increase treatment costs, leading to a rise in the cost of drinking water. Sectors such as commercial fishing, recreational businesses, and tourism rely heavily on clean water and can be directly affected by oil spills and leaks.

It is worth noting that not all oil pollution is anthropogenic; oil can also be released from natural sources such as seeps in the ocean floor and eroding sedimentary rocks. However, the frequency and severity of oil spills and leaks caused by human activity highlight the need for better waste management and pollution control measures to protect our water resources.

Agricultural processes

Agriculture is the largest user of freshwater resources, using about 70% of the Earth's surface water supplies. It is also a serious water polluter. Agricultural processes such as the uncontrolled spreading of slurries and manures, tillage, and ploughing the land can cause water pollution.

Fertilizers, pesticides, and animal waste from farms and livestock operations wash nutrients and pathogens, such as bacteria and viruses, into waterways. Nutrient pollution, caused by excess nitrogen and phosphorus in water or air, is the number-one threat to water quality worldwide and can cause harmful algal blooms.

Pesticides and fertilizers used in agriculture can contaminate both groundwater and surface water. To protect their crops from bacteria and insects, farmers often use chemicals and pesticides. When these substances seep into the groundwater, they can harm animals, plants, and humans. When it rains, the chemicals mix with rainwater, which then flows into rivers and streams, filtering into the ocean and causing further water pollution.

The unsafe use of non-conventional sources of water, especially wastewater, in agriculture can lead to the accumulation of microbiological and chemical pollutants in crops, livestock products, and soil and water resources. This can ultimately lead to severe health impacts among exposed food consumers and farm workers.

Microplastics

To reduce microplastics in water, individuals can use products made with bio-based and biodegradable plastics and wrapped in sustainable packaging. Recycling and reusing plastic products are also effective remedies if every individual actively participates.

Frequently asked questions