Surface Water Pollution: Understanding Contamination Sources

Surface water pollution is a pressing issue that poses significant risks to both human health and the environment. It refers to the contamination of bodies of water found on the Earth's surface, such as oceans, lakes, and rivers. These water sources are vulnerable to pollution due to their exposed nature, and the use of water for various human activities such as agriculture, industry, and municipal purposes.

Surface water pollution has several sources, including agricultural runoff, sewage and wastewater, oil pollution, and radioactive substances. Human waste, fertilizer seepage, industrial byproducts, and poorly maintained waste systems are common contributors to surface water contamination. Additionally, adverse weather events like flooding can also lead to pollution as they spread contaminated water to areas usually untouched by water.

The consequences of surface water pollution are far-reaching. Contaminated water can cause various illnesses, including waterborne diseases, and can lead to toxic products remaining in fish. It also affects the color and turbidity of the water, with tannins formed from organic material such as branches, soil, and debris.

To ensure a safe water supply and reduce health risks, municipal authorities must implement regular testing and treatment programs to address surface water pollution effectively.

Fertilizer and chemical run-off from farms

Fertilizers and chemicals are often used on farms to promote crop growth and increase yields.

Sewage and wastewater

The treatment and disposal of sewage and wastewater are crucial to preventing surface water pollution. Untreated or inadequately treated wastewater is a significant concern, as it releases pollutants such as nutrients, pathogens, suspended solids, and organic and inorganic substances into water bodies. These contaminants can have detrimental effects on aquatic ecosystems and human health. For example, high levels of organic material in sewage, indicated by biochemical oxygen demand (BOD), can deplete oxygen levels in water bodies, leading to the death of aquatic species and the creation of anaerobic conditions.

Additionally, sewage and wastewater can introduce chemical compounds from personal hygiene and cosmetic products, disinfection by-products, hormones, synthetic materials, insecticides, herbicides, and pathogens into water bodies. These contaminants can have adverse effects on the natural biota and potentially on humans if the water is used for drinking. Inadequately treated wastewater can also introduce nutrients, pathogens, suspended solids, and organic fecal matter, leading to eutrophication and algal blooms, which further degrade water quality.

The improper disposal of sewage and wastewater has far-reaching consequences. According to the United Nations, more than 80% of the world's wastewater is discharged into the environment without adequate treatment or reuse, contributing to surface water pollution. This untreated wastewater contains a range of pollutants, including household effluent, human waste, toxic chemicals, and medical waste, which contaminate the environment and pose risks to public health.

To address these issues, it is essential to improve wastewater management practices, including the treatment and safe reuse of wastewater. By implementing effective treatment processes, such as advanced technology at wastewater treatment facilities, the levels of pollutants can be significantly reduced before the water is discharged into waterways. Well-designed and operated treatment systems can remove 90% or more of the pollutant load in sewage.

Oil pollution

Impact on Marine Life

Oil spills are harmful to marine birds, mammals, fish, and shellfish. Oil can destroy the insulating ability of fur-bearing mammals, such as sea otters, and the water repellency of a bird's feathers, thus exposing these creatures to harsh elements. Without the ability to repel water and insulate from cold water, birds and mammals will die from hypothermia. Juvenile sea turtles can become trapped in oil and mistake it for food. Dolphins and whales can inhale oil, which can affect their lungs, immune function, and reproduction. Many birds and animals also ingest oil when they try to clean themselves, which can poison them. Oil can also make fish and shellfish unsafe for humans to eat.

Impact on Humans

Oil spills can ruin a day at the beach and make seafood unsafe to eat. They can also cause big problems as oil is lighter than water and rises through the ocean after spills.

Clean-up

Clean-ups after oil spills usually focus on the oil slick on the water's surface. However, research from the University of Illinois Chicago shows that some oil may remain suspended in the water. Increasing the viscosity of the water can help keep the oil drops intact so that the entire drop goes into the oil slick above the surface, making clean-up easier.

Radioactive substances

Natural Sources of Radioactivity in Water

Radioactive materials, called radionuclides, can be found in the earth's crust and atmosphere. Radionuclides from these natural sources can contaminate groundwater and surface waters. Examples of natural radionuclides include radium, uranium, radon, and thorium. Uranium, for instance, is naturally found in oceans and seas, while radon, a radioactive gas, can be present in groundwater.

Human-Made Sources of Radioactivity in Water

Human activities also contribute to the presence of radioactive substances in water. Nuclear weapons testing, nuclear power plants located near water bodies, and the disposal of radioactive waste are significant sources of radioactive pollution in surface water. Additionally, the use of radioactive materials in medical treatments, such as radioactive iodine for thyroid disorders, can introduce radioactivity into water supplies.

Health Risks of Radioactive Water Pollution

The ingestion of radioactive water and exposure to contaminated water sources pose health risks. The radiation from contaminated water can be absorbed into the blood and accumulate in specific tissues, causing damage. For example, ingested radium deposits mostly in the bone, while uranium affects the kidneys and bones. Prolonged exposure to radioactive water increases the risk of cancer, especially if consumed daily over many years. Other potential health effects include acute radiation syndrome, cutaneous radiation injury, genetic mutations, and various disorders in human physiology.

Preventive Measures and Treatment

To prevent radioactive pollution in water, it is crucial to identify potential sources of contamination and prepare for emergencies such as spills or accidents. Public drinking water systems also play a vital role in ensuring water safety by regularly testing and treating water to remove radioactive contaminants.

Various treatment methods are available to remediate radioactive water contamination. These include aeration, reverse osmosis, ion exchange, and granule carbon adsorption.

Industrial waste

The release of chemical solvents and the improper disposal of hazardous waste are also major contributors to surface water pollution. In the United States, the Environmental Protection Agency (EPA) regulates 94 chemicals in drinking water sources but doesn't set standards for many others. As a result, the drinking water of more than 244 million people contains contaminants that can be linked to industrial practices and are not currently regulated.

Another issue is thermal pollution, which occurs when water used for cooling industrial processes is discharged back into water bodies at elevated temperatures. This can lead to decreased oxygen levels, killing fish and altering food chain composition, reducing species biodiversity, and allowing the invasion of new thermophilic species.

The effects of industrial waste on surface water are far-reaching. It can kill marine life, cause illness in those who consume contaminated animals, and reduce the reproductive ability of aquatic life. It can also have serious consequences for human health, with unsafe water causing approximately 1.8 million deaths in 2015, according to a study published in The Lancet.

To address the issue of industrial water pollution, policy changes, effective enforcement, controlled industrial growth, investment in sustainable technologies, and improved waste disposal and treatment are necessary.

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