Water Pollution: The Top Sources And Their Impacts

Water is essential for human survival, but it is also a limited resource. Less than 1% of water on Earth is available for human use, and global freshwater use has increased six-fold since 1900. The top consumers of water are agriculture, industry, and municipal uses. Agriculture accounts for 70% of global freshwater withdrawals, while energy production is the second-largest consumer of freshwater resources. Water pollution, caused by a variety of human activities, further threatens this limited resource. Point source pollution, such as wastewater discharged by manufacturers or oil refineries, is easier to control than nonpoint source pollution, which includes agricultural runoff or stormwater. Other sources of water pollution include oil spills, toxic waste, and pathogenic microorganisms.

Industrial waste

Industrial solid waste can be solid, liquid, or gas held in containers, and it is divided into hazardous and non-hazardous waste. Hazardous waste may result from manufacturing or other industrial processes, and it includes toxic chemicals and pollutants. Many industrial sites produce waste in the form of toxic chemicals and pollutants, and though regulated, some still do not have proper waste management systems in place. In rare cases, this waste is dumped into nearby freshwater systems. When industrial waste is not treated properly, or not treated at all, it can easily pollute the freshwater systems that it comes into contact with.

The waste produced by these industries can make water unsafe for human consumption, and it can also cause the temperature in freshwater systems to change, making them dangerous for many water-dwelling organisms. It can also be a threat to the entire environment as all life forms are directly or indirectly connected to natural waterways for their survival.

To address the environmental and health issues created by industrial wastewater, it is necessary to treat it with physical, chemical, and biological means so that it can be recycled for water conservation. Several treatment plants are being set up to release potable water, and many industrial developers and manufacturers are now adopting technologies to ensure cleaner production, less water consumption, and less pollution.

Sewage and wastewater

Sewage pollution encompasses everything that is flushed down toilets or washed down drains and subsequently released into the environment through sewer overflows or runoff from land and roads. The UK, for instance, faces challenges with its aging sewerage system, which often results in the discharge of raw sewage into rivers and the ocean. This has led to a decline in water quality, with only 14% of UK rivers achieving "good" ecological status.

Wastewater, on the other hand, refers to used water from sinks, showers, and toilets, as well as commercial, industrial, and agricultural activities. It includes metals, solvents, toxic sludge, and stormwater runoff, which occurs when rainfall washes pollutants like road salts, oil, grease, and chemicals into waterways. More than 80% of the world's wastewater is released back into the environment without proper treatment, and in less developed countries, this figure can exceed 95%.

To address this issue, wastewater treatment facilities play a crucial role. In the United States, for example, these facilities process approximately 34 billion gallons of wastewater daily, reducing pollutants such as pathogens, phosphorus, and nitrogen in sewage, as well as heavy metals and toxic chemicals in industrial waste. However, it is important to acknowledge that even these treatment systems have limitations, and according to EPA estimates, they release over 850 billion gallons of untreated wastewater annually.

To mitigate the impact of sewage and wastewater on water pollution, several measures can be implemented. Firstly, investing in upgrading sewerage infrastructure and improving waste management practices can help reduce the incidence of raw sewage discharge. Additionally, implementing stricter regulations and enforcement of existing regulations can hold water companies accountable for their environmental performance. Public awareness and education about proper waste disposal, plastic reduction, and responsible chemical handling can also play a significant role in reducing sewage and wastewater pollution.

Mining activities

Mining also affects water sources through pollution. Water pollution from mining activities can render water virtually unusable, threatening drinking water supplies and the wildlife that depends on these water sources. There are several ways in which mining causes water pollution. Firstly, there is acid mine drainage (AMD), a process by which sulphuric acid is produced when sulphides in rocks are exposed to air and water. AMD severely degrades water quality and can kill aquatic life. The acid is carried off the mine site by rainwater or surface drainage and deposited into nearby streams, rivers, lakes, and groundwater.

Secondly, there is heavy metal contamination. Heavy metal pollution occurs when metals such as arsenic, cobalt, copper, cadmium, lead, silver, and zinc, which are contained in excavated rock or exposed in an underground mine, come into contact with water. Even trace amounts of heavy metals in water sources can pose serious health problems for humans and other aquatic life.

Other ways in which mining causes water pollution include the use of chemical compounds such as sulphuric acid or cyanide to separate target minerals from the ore. These chemicals are highly toxic and can lead to severe health concerns and loss of life in wildlife species.

The impact of mining on water sources is felt for a long time, sometimes for decades or centuries after a mine has been closed. This impact depends on various factors, including the sensitivity of the local terrain, the composition of the minerals being mined, the type of technology employed, and the company's skill, knowledge, and environmental commitment.

There is growing awareness of the environmental legacy of mining activities, and efforts are being made to enhance environmental standards and regulations in mines to reduce pollution.

Marine dumping

Until the 1970s, communities worldwide used the ocean as a dumping ground for waste, but this practice changed as the harmful impacts of unregulated disposal became evident. Today, the deliberate disposal of waste into the ocean is governed by international treaties and regulations, such as the 1972 London Convention and the 1996 London Protocol, which establish global rules and standards for preventing, reducing, and controlling marine pollution.

Dredging is a significant contributor to marine dumping, accounting for about 80% of all waste dumped into the ocean. Rivers, canals, and harbors are dredged to remove silt and sand buildup or to create new waterways. Approximately 20-22% of the dredged material is dumped into the ocean, with the rest disposed of in other waters, landfills, or used for development. Unfortunately, about 10% of dredged material contains pollutants such as heavy metals, hydrocarbons, nutrients, and pesticides, which can have toxic effects on marine organisms and contaminate seafood.

Litter items such as plastic packaging, fishing lines, and plastic bags can entangle or be ingested by marine animals, leading to injury, infection, or death. Seabirds, turtles, dolphins, and seals are particularly vulnerable to plastic debris, which can cause slow and painful deaths. Marine debris can also damage boat engines and clog intake valves and ports. While the risk to human health is considered small, the long-term effects of nuclear dumping are unknown, and some predict potential deaths in the next 10,000 years due to nuclear waste.

To address marine dumping, countries have implemented various measures, such as the United States' Marine Protection, Research, and Sanctuaries Act (MPRSA), which regulates the disposition of materials into the ocean and works to protect human health and the marine environment. The MPRSA has been successful in preventing many harmful materials from entering the oceans, and similar efforts are being made globally to reduce the impact of marine dumping on our oceans and marine life.

Oil leakage

Oil exploration, refining, and distribution all pose inherent risks to water resources. As oil products are the primary energy source for transportation in most countries, accounting for over 90% of transport energy, any disruption in oil supply can have far-reaching consequences beyond mobility, including impacts on food production, heating, and medical care. However, the very process of exploring for, refining, and distributing oil can lead to water pollution through accidents, leakages, and spills.

Off-shore oil exploration, in particular, creates significant risks for marine life. Oil transportation and pipeline transportation also increase the danger of ecological damage in the event of oil leakages. Oil spills on ocean surfaces have detrimental effects on aquatic life. They hinder sunlight penetration, reduce dissolved oxygen levels, and impair the insulating and waterproofing abilities of feathers and fur, leading to hypothermia in birds and marine mammals. Additionally, ingested oil is toxic to these animals, and the damage to their habitats and reproductive rates can prolong the recovery of affected populations.

While tanker spills contribute about 10% of the oil in waters globally, land-based sources, such as factories, farms, and cities, are responsible for nearly half of the estimated one million tons of oil that enters marine environments annually. This includes oil drips from cars and trucks, emphasizing that consumers are the primary source of oil pollution in the seas. Natural seepage from the ocean floor, along with the release of used gasoline solvents and lubricants by industries and individuals, further exacerbates the problem, adding millions of metric tons of oil to the world's waterways each year.

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