Sources Of Surface Water Pollution: What You Need To Know

Surface water pollution is a pressing issue that affects the quality of freshwater resources and poses serious health risks to humans and the environment. It occurs when various contaminants find their way into bodies of water, such as oceans, lakes, rivers, and streams. The leading sources of surface water pollution include agricultural runoff, sewage and wastewater discharge, oil pollution, and radioactive substances. Other significant contributors include chemical dumping, algal blooming, sediment from soil erosion, and industrial waste. The impact of surface water pollution is far-reaching, endangering aquatic life and ecosystems, as well as compromising drinking water supplies for human consumption.

Agricultural sources: animal waste, fertilisers, pesticides, and herbicides

Agriculture is the leading cause of water degradation worldwide. The sector is the biggest consumer of freshwater resources, with farming and livestock production using about 70% of the world's surface water supplies.

Animal Waste

Animal agriculture is one of the largest drivers of water pollution due to the overwhelming amount of waste generated as a byproduct of animal-derived food production. Factory farms, which house thousands of animals in a relatively small area, produce waste high in nutrients, including nitrates, which have become the most common contaminant in groundwater aquifers. This waste also contains antibiotics and other veterinary drugs, which can have significant environmental and public health impacts.

Fertilisers

Fertilisers are materials added to the soil to increase its fertility and typically contain nitrogen, phosphorus, and potassium. When used in excess, these nutrients can wash into waterways, causing nutrient pollution, which is the number one threat to water quality worldwide. Nitrogen and phosphorus in water can cause algal blooms, which are harmful to people and wildlife. Fertilisers can also be toxic to humans, with the potential to cause health risks, especially for young children.

Pesticides and Herbicides

The growing global population has increased the demand for food and, consequently, the use of pesticides and herbicides to maximise crop yields. These chemicals are designed to be toxic and can be deadly to aquatic organisms, affecting the entire food chain. They can also be harmful to human health, with the potential to cause health issues such as hematologic and hormonal abnormalities and infertility. Pesticides and herbicides can enter water sources through various means, including wind, water runoff, and atmospheric weathering processes.

Industrial sources: manufacturing, factories, and power plants

Industrial sources, including manufacturing, factories, and power plants, are significant contributors to surface water pollution. This occurs through the discharge of untreated or inadequately treated wastewater into nearby water bodies.

Manufacturing and factories are major sources of industrial water pollution. Various industries, such as chemical plants, plastics manufacturers, and fertilizer plants, release a range of contaminants. For instance, chemical plants produce toxic chemicals like PVC and vinyl chloride, which can spill during transportation or as a result of accidents. Plastics manufacturers contribute to water pollution by releasing synthetic fibers, such as polyester, into the environment. Fertilizer plants, on the other hand, discharge nutrients like nitrogen, which can lead to eutrophication and algal blooms, causing oxygen depletion and the death of aquatic life.

Inorganic chemical plants are among the biggest industrial dischargers of toxic pollution. These plants produce chemicals that are harmful to both human health and the environment. The Environmental Protection Agency (EPA) in the United States has been criticized for its failure to update regulations and enforce stricter standards on industrial polluters. This has resulted in the continuous release of heavy metals, toxic chemicals, and other pollutants into waterways.

Power plants, particularly those using coal or oil, are also responsible for water pollution. Coal-fired power plants can contaminate water sources with chemicals like chromium-6. Oil refineries discharge wastewater containing heavy metals, oils, and industrial salts, posing a threat to aquatic life and human health.

It is important to note that industrial waste is not limited to direct pollution. Indirect pollution occurs when waste and pollutants are left on land, eventually making their way into groundwater and contaminating water sources. This type of pollution can have long-lasting effects, requiring years or even decades to fully remediate.

To address industrial water pollution, governments must establish and enforce stringent clean water standards. Manufacturers should prioritize wastewater treatment and adopt sustainable practices to reduce their environmental impact and protect valuable water resources.

Oil pollution: vehicle leaks, factories, and tanker spills

Oil pollution is a significant contributor to surface water contamination. It can enter water bodies through various means, including vehicle leaks, industrial discharges, and tanker spills.

Vehicle leaks are a common source of oil pollution. Cars, trucks, and other vehicles can leak oil, antifreeze, or coolant onto roads and parking lots, which then washes into storm drains and eventually reaches rivers, lakes, and oceans. To prevent this, it is essential to maintain vehicles properly and fix any leaks promptly.

Factories and industrial facilities are another source of oil pollution. Many industrial processes use oil as a lubricant, coolant, or fuel, and improper handling or disposal of oil can lead to contamination of nearby water sources. Additionally, factories may discharge oily wastewater into rivers or seas, further contributing to surface water pollution.

Tanker spills, while less frequent than they used to be, can have devastating consequences for the environment. Oil tankers transport large quantities of oil over long distances, and accidents or malfunctions can result in significant oil spills. These spills often occur during the loading or unloading process, or due to collisions or groundings. In 2024, six large spills and four medium spills were recorded, resulting in approximately 10,000 tonnes of oil lost to the environment. While the frequency of spills has decreased over the past few decades, the impact of a single large incident can severely distort the spill volume for a particular year.

The effects of oil pollution on water bodies are far-reaching. Oil forms a thick layer on the surface, preventing oxygen exchange and smothering aquatic life. It also coats birds' and marine animals' feathers and fur, impairing their ability to move and regulate body temperature. Oil spills can have long-lasting impacts on ecosystems, and even though some oil evaporates or breaks down naturally, the process can take years.

To address oil pollution, it is crucial to implement preventive measures, such as regular vehicle maintenance and strict regulations for industrial operations and oil transportation. Additionally, public education and proper waste disposal practices can help reduce the amount of oil entering our surface waters.

Radioactive substances: nuclear waste

Radioactive substances, also known as radionuclides, are both naturally occurring and human-made. They can be found in the earth's crust and in the air, water, and soil around us. While small amounts of radiation are common, exposure to high levels of radiation can cause health problems.

Nuclear waste is a significant source of radioactive substances in surface water. Nuclear power plants, reprocessing plants, and military activities generate nuclear waste that contains radioactive materials. In some cases, this waste is improperly disposed of, leading to water pollution. For example, a British nuclear fuels plant has repeatedly released radioactive waste into the Irish Sea, and a French nuclear reprocessing plant has discharged waste into the English Channel.

Nuclear accidents and calamities can also result in the release of radioactive substances into surface water. The Fukushima nuclear disaster in Japan, caused by an earthquake and tsunami in 2011, led to the release of thousands of tons of radioactive water into the Pacific Ocean. Similarly, the Chernobyl disaster in 1986 resulted in the contamination of local waterways.

In addition to these direct releases, atmospheric fallout from nuclear accidents can contaminate surface water through rainfall. Radioactive particles can be carried by wind and deposited into the soil, and subsequent rainfall can wash these contaminants into streams and rivers, ultimately infiltrating groundwater aquifers.

The mining of radioactive elements, such as uranium and thorium, can also lead to surface water pollution. Uranium mining, in particular, has been associated with water contamination in several regions. Furthermore, the use of radioactive elements in medical treatments, such as radioactive iodine for thyroid disorders, can introduce radioactive substances into water supplies.

Household sources: pharmaceuticals, chemicals, and plastics

Surface water pollution is a critical issue that jeopardizes public health. It arises from various sources, including household activities that introduce pharmaceuticals, chemicals, and plastics into water bodies.

Pharmaceuticals

Pharmaceutical pollution is a growing concern, with prescription drugs, over-the-counter medications, and personal care products finding their way into lakes, rivers, and streams. Our bodies can only metabolize a fraction of the drugs we ingest, and the unabsorbed portions are excreted and enter the wastewater. Additionally, medications applied topically, such as creams and lotions, can also contribute to water pollution when washed off. Drug manufacturing facilities and agricultural practices, where hormones and antibiotics are administered to animals, further compound this issue.

Chemicals

Chemicals from household products, such as cleaners, oils, and pesticides, can contaminate water sources if not properly disposed of or if they leak into the environment. These chemicals can enter our rivers, lakes, and oceans, posing risks to aquatic life and human health. Improper disposal of household chemicals can have detrimental effects, as evidenced by the Pittston Coal Company disaster in 1972, where a dam burst and released millions of gallons of toxic wastewater, leading to devastating consequences for nearby residents.

Plastics

Plastic pollution has become a pressing environmental issue, with single-use plastics accounting for a significant portion of the problem. These plastics, such as bags and food wrappers, have short lifespans but persist in the environment for hundreds of years. Once plastics break down into microplastics, they are nearly impossible to retrieve from the water. Plastics can be transported by rivers into the oceans, affecting coastal waters and spreading worldwide through ocean currents. Plastic waste harms animal life, and its presence in the food chain may also impact human health.

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