Water Bodies: Sources Of Pollution And Ways To Prevent It

Water pollution is the contamination of water bodies, including lakes, rivers, oceans, and reservoirs, which has a detrimental impact on their uses. It is predominantly caused by human activities, such as industrial waste, sewage discharges, and agricultural activities, but can also be caused by natural events like oil spills and mercury filtering from the Earth's crust. Water pollution can have severe consequences, including the degradation of aquatic ecosystems, the spread of water-borne diseases, and a negative impact on the economy. With water being an essential resource for all living beings, protecting it from pollution is of utmost importance.

Industrial waste

The production of industrial goods generates wastewater that can be contaminated with toxic substances. This wastewater is often discharged into nearby freshwater systems, such as rivers, streams, and other bodies of water that lead to the sea. In some cases, this wastewater is treated or recycled, but in other cases, it is discharged untreated, polluting the water and making it unsafe for human consumption.

The types of pollutants found in industrial wastewater include petroleum products, heavy metals such as copper, lead, and selenium, hazardous wastes such as flammable and corrosive materials, and sediments containing non-degradable toxins. These toxins can accumulate in aquatic sediments for years and slowly enter the groundwater or be stirred up into lakes and rivers.

In addition to the direct discharge of wastewater, industrial waste can also contaminate water through improper waste disposal and dumping. For example, mining and smelting operations can contaminate water with heavy metals, and dry cleaning fluids can contaminate groundwater supplies.

The effects of industrial water pollution can be devastating, not only to people but also to animals, fish, and birds. It can destroy aquatic life, reduce reproductive ability, and cause health issues such as the spread of diseases. It can also have negative economic impacts, affecting sectors such as commercial fishing, recreational businesses, tourism, and property values.

To address the issue of industrial water pollution, regulations and policies have been put in place, such as the EU's 'Zero Pollution Action Plan'. However, enforcement and monitoring of these regulations can be inconsistent, especially in emerging countries with rapidly growing industrial sectors.

Sewage and wastewater treatment

Sewage is a primary source of pathogens, or disease-causing microorganisms, and putrescible organic substances. These pathogens include bacteria, viruses, protozoans, and parasitic worms, which can cause waterborne diseases such as cholera, hepatitis A, and dysentery. Inadequately treated wastewater can convey these pathogens, as well as nutrients, heterogenous suspended solids, and organic fecal matter, into water bodies. The EPA estimates that aging and overwhelmed sewage treatment systems in the United States release more than 850 billion gallons of untreated wastewater each year. This untreated wastewater contains pollutants such as pathogens, phosphorus, nitrogen, heavy metals, and toxic chemicals, which can have detrimental effects on aquatic ecosystems and human health.

One of the consequences of sewage pollution is the promotion of algae growth, which can eventually lead to eutrophic "dead zones" where aquatic life cannot survive due to a lack of oxygen. This process, known as eutrophication, is accelerated by human activity and water pollution, resulting in the premature aging and death of water bodies. When algae die, microorganisms use oxygen for their decomposition, reducing the oxygen available for aquatic life. Anaerobic organisms then metabolize the organic wastes, releasing harmful gases such as methane and hydrogen sulfide.

Wastewater treatment facilities play a crucial role in reducing the amount of pollutants in sewage and industrial waste before discharging the treated water into waterways. These facilities process about 34 billion gallons of wastewater per day in the United States. However, it is important to recognize that even treated sewage discharges can still contain chemical compounds from personal hygiene and cosmetic products, as well as disinfection by-products, which can impact the quality of water bodies.

Oil spills

The cleanup and recovery from an oil spill are challenging and can take weeks, months, or even years. The process depends on several factors, including the type of oil spilled, the temperature of the water, and the types of shorelines and beaches involved. Physical cleanups of oil spills are very expensive. Before the 1960s, the best remediation method involved putting straw on the spill and manually retrieving the oil-soaked straw.

Solid waste

The improper disposal of solid waste has serious environmental, health, and economic consequences. It is unsightly and damages the health of aquatic ecosystems, harming wildlife directly. Many solid wastes, such as plastics and electronic waste, break down and leach harmful chemicals, toxic metals, and other contaminants into the water, making them a source of toxicity. These contaminants can be lethal for all ecosystems and can render water unsafe for human use.

In addition to direct disposal into water bodies, solid waste can also contribute to water pollution in other ways. For example, flooding can wash and move solid waste and contaminated soils into rivers and wetlands. Monsoon flooding in India, for instance, has been shown to worsen water pollution in the country. Furthermore, solid waste that is not properly managed can accumulate in urban areas, creating unhygienic conditions and releasing pollutants that leach into surface and groundwater.

The problem of solid waste pollution is particularly acute in developing countries that lack the infrastructure or resources to properly dispose of solid waste and have inadequate regulations to limit improper disposal. However, solid waste pollution is a global issue, with huge quantities of solid waste being generated worldwide. The generation rates of municipal solid waste are higher than any other environmental pollutant, including greenhouse gases. This waste often ends up in freshwater bodies, which are already limited in quantity, further reducing the availability of clean water for human use.

Agricultural activities

Agriculture is a major contributor to water pollution. It is the single largest user of freshwater on a global basis and accounts for 70% of water withdrawals worldwide. Farms discharge large quantities of agrochemicals, organic matter, drug residues, sediments, and saline drainage into water bodies.

Another source of water pollution is livestock and their manure. According to the EPA, manure management alone accounts for 12% of all agricultural greenhouse gas emissions in the United States. Globally, it accounts for 14.5%. Manure emits ammonia, which combines with other air pollutants to create harmful solid particles that can cause heart and lung diseases.

Aquaculture is also recognised as a major problem in freshwater, estuarine, and coastal environments, leading to eutrophication and ecosystem damage. Fish excreta and uneaten feeds from fed aquaculture diminish water quality. Increased production has combined with greater use of antibiotics, fungicides, and anti-fouling agents, which may contribute to polluting downstream ecosystems.

Agricultural non-point source pollution, also known as "diffuse" source pollution, is a leading source of harm to water quality for surveyed rivers and streams. It arises from a broad group of human activities, and the pollutants have no obvious point of entry into receiving watercourses. This type of pollution is much more difficult to identify, measure, and control than point-source pollution, where wastewater is directly routed into receiving water bodies.

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