Water Pollution: Understanding The Ten Key Causes

Water pollution is a pressing global issue that affects one in three people on the planet. It is caused by a variety of factors, including human activity and natural processes. The contamination of water sources by harmful microorganisms and chemical substances leads to a decrease in water quality, making it toxic and unsuitable for human use. This pollution has severe consequences for human health, the environment, and the economy. With rising global concerns, it is essential to explore and address the ten main causes of water pollution.

Oil spills and leaks

Oil spills can have devastating ecological, economic, and social consequences. Oil on the ocean surface can harm aquatic life by reducing the amount of sunlight that penetrates and decreasing oxygen levels in the water. Oil coats the feathers and fur of birds and marine mammals, impairing their insulating and waterproofing abilities and making them more susceptible to hypothermia and buoyancy issues. Ingesting oil can be toxic to animals, and the damage to their habitats and reproductive rates may hinder the long-term recovery of populations. Oil spills also damage plant life, including saltwater marshes and mangroves. If beaches and populated coastlines are affected, tourism and commerce may suffer, and power plants and other utilities that rely on seawater may be disrupted.

The cleanup and recovery process following an oil spill is complex and challenging. Factors such as the type of oil spilled, water temperature, and shoreline characteristics influence the approach and duration of the cleanup. Complete removal of spilled oil is unattainable, and cleanup efforts must consider the potential for additional harm. For example, after the Exxon Valdez oil spill in 1989, it was found that high-pressure, hot-water hoses used in the cleanup process caused more damage than the oil alone. The Oil Pollution Act of 1990 established that those responsible for oil spills are liable for the costs of cleanup and restoration.

Oil spills from pipelines are estimated to contribute 1% of oil pollution in the oceans, with pipeline leaks on land accounting for most of the pollution. Trawling of fishing boats, natural disasters, pipe corrosion, construction defects, sabotage, or attacks are among the causes of pipeline oil spills. Oil can enter waterways as runoff from roads, rivers, or land vehicles, particularly during rainstorms. Land-based spills differ from maritime spills in that the effects remain local as oil spreads more slowly on land.

Industrial waste

The most polluting sources of water pollution are city sewage and industrial waste discharged into rivers. Industrial waste from agricultural sites, mines, and manufacturing plants can make its way into rivers, streams, and other bodies of water that lead directly to the sea. The toxic chemicals in the waste produced by these industries can make water unsafe for human consumption and also cause the temperature in freshwater systems to change.

A News21 analysis of EPA data shows that the drinking water of more than 244 million people in the US contains contaminants linked to industrial practices that are not currently regulated. Mining and smelting operations are responsible for contaminating water with heavy metals in almost every state in the US. For example, Anaconda Aluminum in Montana produced manufacturing wastes that contaminated local water sources with lead and chromium, and Gulf States Utilities in Louisiana discharged toxins into marshlands, polluting waters with benzene and other chemicals.

The effects of water pollution are devastating to people, animals, fish, and birds. Polluted water is unsuitable for drinking, recreation, agriculture, and industry. It diminishes the aesthetic quality of lakes and rivers, destroys aquatic life and reduces its reproductive ability. It can also cause treatment costs to rise, which in turn makes the cost of drinking water increase as well.

While most major industries have treatment facilities for industrial effluents, this is not the case with small-scale industries, which cannot afford huge investments in pollution control equipment. Technologies have been developed to solve a range of solid waste and other environmental and recycling problems, including the separation and recycling of fly ash, metals, plastics, glass, and sands.

Agricultural chemicals

Agriculture is the world's largest user of freshwater and a major cause of surface and groundwater degradation through erosion and chemical runoff. The associated agrofood-processing industry is also a significant source of organic pollution.

Agricultural runoff is a significant source of water pollution. When rainwater or melting snow washes over fields, it can carry pesticides, fertilizers, and other chemicals into nearby waterways. This type of non-point source pollution is difficult to control as it comes from many different sources and can be challenging to identify. However, it ultimately finds its way into groundwater, wetlands, rivers, and lakes, and eventually the oceans.

The use of pesticides and other chemicals in agriculture can have severe ecological impacts. They can harm fish, birds, and other wildlife, as well as contaminate drinking water supplies. Additionally, the excessive use of fertilizers can cause eutrophication, leading to oxygen depletion and the creation of dead zones in water bodies.

To mitigate the negative impacts of agricultural chemicals, proper waste disposal and integrated pest management are essential. Communities also need to be educated about the pollution impacts of fertilizers and chemicals on water quality and food safety. By implementing these measures, we can minimize the adverse effects of agricultural chemicals on our water resources and protect the environment and public health.

Sewage and wastewater

Sewage pollution can have detrimental effects on the environment, leading to habitat loss, extinction, and biodiversity loss. It can cause seagrass die-offs, harmful algal blooms, and weakened reefs, as seen in coastal areas such as Richardson Bay in California and the Caribbean coast of Colombia. In Barbados, sewage pollution has altered the species composition of coral reefs through eutrophication, which occurs when excessive nutrients, often from untreated sewage, fertiliser runoff, and agricultural waste, enter bodies of water.

The impact of sewage and wastewater pollution extends beyond the environment, posing risks to human health. Untreated sewage contains elevated levels of pathogenic microorganisms, such as viruses and bacteria, which can lead to the spread of diseases. According to the United Nations, water pollution causes more deaths annually than all forms of violence combined, including war. This is evident in rivers like the Ganges, which has become heavily polluted with faecal bacteria, endangering the health of millions of people.

Furthermore, sewage and wastewater pollution have economic implications. It affects sectors such as commercial fishing, recreational businesses, and tourism, which rely on clean water. The treatment of polluted drinking water also incurs additional costs, leading to increased water prices. David Malpass, the president of the World Bank, has emphasised the economic impact of deteriorating water quality, stating that it "stalls economic growth and exacerbates poverty in many countries."

While organisations like Scottish Water are working to minimise sewage pollution, individual actions play a crucial role. Flushing inappropriate items, such as wipes, nappies, or cooking fats, can cause drain blockages and flooding, leading to environmental pollution. Proper waste disposal and awareness of the impacts of sewage and wastewater pollution are essential to mitigating this issue.

Plastic pollution

Plastic is a non-biodegradable material that does not dissolve in land or water. It stays in the ecosystem for a long time, causing a hazard to wildlife and spreading pollutants. Plastic is commonly used in our daily lives, and it is difficult to find a substance that is not made of plastic. Because of its widespread use, more and more plastic is being dumped into the ocean each year, and it is having a detrimental impact.

Plastic waste makes its way from our homes and offices to landfills and bodies of water, causing contamination. It is often mistaken for food by aquatic animals, who eat it and eventually die. For example, a dolphin died due to a plastic ring stuck in its mouth, and it is common for turtles to mistake plastic bags for jellyfish. Plastic can also get caught around wildlife, such as seals, who can die from starvation, exhaustion, or infection as a result.

Plastic is also released into the atmosphere when it is burned, releasing greenhouse gases and hazardous air pollution, including toxins that can cause cancer. The problem is not plastic itself, but the excessive use of plastics and the careless disposal of them. To reduce plastic pollution, we must use alternatives like cloth bags and paper bags, reuse plastic, and avoid bottled water. Governments must also impose strict regulations to discourage the use of plastic goods.

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