Water Pollution: Sources And Impacts On Our Resources

Water pollution is a pressing issue that poses a significant threat to both human health and the environment. It occurs when harmful substances, such as chemicals, waste, and microorganisms, contaminate water sources, degrading water quality and rendering it unsafe for human use. This contamination can have detrimental effects on aquatic ecosystems, leading to the destruction of biodiversity and the contamination of the food chain. The main sources of water pollution include industrial waste, agricultural runoff, sewage and wastewater treatment, and oil spills. Additionally, improper solid waste disposal and marine dumping further contribute to the pollution of our water resources. With only a limited amount of freshwater available and increasing global demand, it is crucial to address the issue of water pollution to ensure the health and well-being of both current and future generations.

Industrial waste and sewage

The increased population has led to a higher demand for goods, resulting in rapid industrialization and a subsequent increase in industrial waste. This waste is released into water bodies, causing environmental and health issues. Shale gas extraction, for example, produces large volumes of wastewater containing high concentrations of dissolved solids, radionuclides, metals, and other drilling pollutants. Mining operations also generate waste and create wastewater discharges, impacting surface and groundwater quality and drinking water supplies.

To address these issues, various programs and regulations have been established to control industrial discharges and set standards for releasing municipal and industrial wastes. The US Clean Water Act, Integrated Pollution Prevention and Control (IPPC) in Europe, and the Central Pollution Control Board (CPCB) in India are examples of such initiatives. Additionally, treatment plants are being set up to use chemical, electrochemical, biological, and physical processes to release potable water.

Sewage, another significant contributor to water pollution, introduces disease-causing microorganisms and poisonous substances into water bodies. It can promote algae growth, leading to eutrophic "dead zones" where aquatic life cannot survive due to oxygen depletion. The improper disposal of solid waste, including garbage, electronic waste, construction debris, and industrial activities, also plays a role in polluting water resources. These issues are particularly acute in developing countries lacking the infrastructure or regulations for proper waste management.

Oil spills and transportation

Oil spills are a significant source of water pollution, with thousands occurring in US waters each year. Oil spills can occur anywhere oil is drilled, transported, or used, and they have devastating impacts on surrounding ecosystems. Oil is typically transported by pipes, ships, trucks, or trains to processing plants called refineries. As the number of transfers increases, so does the risk of spilling the oil.

Oil spills can happen during routine maintenance, such as bilge pumping, or through accidents involving tankers, barges, pipelines, refineries, drilling rigs, and storage facilities. Even small spills, such as those that occur during ship refuelling, can cause significant damage, especially in sensitive environments like beaches, mangroves, and wetlands. Oil spills harm sea creatures, make seafood unsafe to eat, and can ruin beaches and coastal areas.

The transportation and storage of oil are subject to leakage that pollutes water resources. Oil spills from large tankers can discharge massive amounts of oil into the water, but collectively, smaller spills from various sources, such as industrial and domestic runoff, release even more oil into the environment. For example, it is estimated that the pavement runoff from a city of five million people can discharge the same amount of oil as a large oil tanker spill.

In addition to transportation and storage, improper disposal of solid waste is a major source of water pollution. Solid waste includes garbage, rubbish, electronic waste, construction and demolition debris, and industrial waste. This waste can be intentionally or unintentionally dumped into bodies of water, leading to pollution. Land pollution can also become water pollution when trash or debris is carried by animals, wind, or rainfall into water sources.

Solid waste and marine dumping

Solid waste is defined as garbage, rubbish, electronic waste, trash, and construction and demolition waste. Solid waste is generated by individual, residential, commercial, institutional, and industrial activities. The improper disposal of solid waste is a major source of water pollution. In some places, solid waste is intentionally dumped into bodies of water. Solid waste can also become water pollution if it is carried by animals, wind, or rainfall to bodies of water.

Marine dumping is the deliberate disposal of waste at sea from vessels, aircraft, platforms, or other man-made structures. Marine dumping can destroy or degrade important habitats for aquatic species, cause coastal erosion, and affect the health and productivity of the marine environment. Marine debris can also damage boat engines by clogging intake valves and ports and becoming tangled around propellers.

The improper disposal of solid waste and marine dumping have severe environmental, health, and economic impacts. Solid waste and marine dumping can contaminate water sources, making them unsafe for human use and disrupting aquatic ecosystems. This can lead to a lack of access to clean water for drinking and sanitation, exposing people to diseases such as cholera, hepatitis A, and dysentery. Unsafe water kills more people each year than war and all other forms of violence combined.

In 1972, the United States became a key member of the London Convention, an international treaty organization that aimed to protect the ocean from the deliberate disposal of wastes. The London Convention prohibits the dumping of certain hazardous materials and requires permits for the dumping of other identified materials. The Marine Protection, Research, and Sanctuaries Act (MPRSA) in the United States implements the requirements of the London Convention and regulates the disposition of materials into the ocean.

To address the issues of solid waste and marine dumping, it is crucial to improve waste management systems and infrastructure, especially in developing countries. Proper disposal and recycling of solid waste can help reduce the amount of waste that ends up in bodies of water. Additionally, enforcing regulations and treaties, such as the London Convention and the MPRSA, can help control and prevent marine pollution from solid waste and marine dumping.

Agricultural waste and fertilisers

Water is essential for all living beings and is crucial for social and economic development, as well as energy production and adaptation to climate change. However, water pollution poses a significant threat to this vital resource. Water pollution occurs when harmful substances contaminate water bodies, degrading water quality and rendering it toxic to humans and the environment.

One major issue is the use of chemical fertilisers and animal manure on farms. While these provide crops with the necessary nitrogen and phosphorus for growth, excess nutrients can be washed from fields into waterways during rain or snow melt and can also leach into groundwater over time. High levels of nitrogen and phosphorus can cause eutrophication of water bodies, leading to hypoxic "dead zones" where aquatic life cannot survive due to a lack of oxygen. Excess nutrients can also contribute to harmful algal blooms (HABs) in freshwater systems, disrupting wildlife and producing toxins harmful to aquatic life.

Improper management of livestock access to streams, rivers, and lakes can also result in agricultural waste polluting water resources. Allowing livestock unrestricted access to water bodies can lead to excess nutrients from animal waste entering the water, degrading water quality. Implementing measures such as fencing off water bodies or adopting integrated farming practices can help prevent this form of pollution.

In addition to chemical fertilisers and animal waste, farms also discharge various other pollutants into water bodies, including agrochemicals, organic matter, drug residues, sediments, and saline drainage. The increased use of antibiotics, vaccines, and growth promoters in veterinary medicine has led to a new class of agricultural pollutants that can move from farms through water to ecosystems and drinking water sources. These pollutants can have detrimental effects on aquatic ecosystems and human health.

To mitigate the impact of agricultural waste and fertilisers on water pollution, farmers can adopt several best management practices. These include applying fertilisers in the proper amounts and at the right time of year, using conservation drainage practices, ensuring year-round ground cover with cover crops or perennial species, and planting field buffers of trees, shrubs, and grasses along field edges, especially those bordering water bodies.

Microplastics and microorganisms

Microplastics are small plastic particles, often less than five millimetres in length, that are found in water resources such as oceans, rivers, and lakes. They can come from larger plastic debris that degrades over time or from microbeads, which are tiny pieces of manufactured plastic used in health and beauty products. These microbeads can pass through water filtration systems and easily end up in water bodies, where they pose a threat to aquatic life. Microplastics can take centuries to decompose and have been found to be harmful, and even fatal, to aquatic organisms through entanglement and ingestion.

Developing nations appear to be dealing with a more severe microplastics problem, with lakes in China and Saudi Arabia showing much higher levels of contamination. Rivers, in particular, favour the accumulation of microplastics due to their relatively low speed of flow, which allows pollutants to reside for longer periods.

To reduce the impact of microplastics, individuals can play a key role by favouring products made with biodegradable materials and sustainable packaging. Recycling and reusing plastic products are also effective ways to reduce plastic pollution. Additionally, consumers can shop more consciously and use reusable containers to minimise packaging waste.

Microorganisms, such as bacteria and viruses, can also pollute water resources. Sewage is the primary source of microbial pollution, with fecal matter, hospitals, industry, and cattle farms contributing to the bacterial load in water bodies. Water-borne pathogens are a significant concern for human health, causing diseases and infections. Enhancing the understanding of pathogen sources and their impacts is crucial for developing effective control measures.

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