Water Pollution: Which Industries Are The Main Culprits?

Water pollution is a pressing issue that affects the lives of millions of people worldwide. While there are many sources of water pollution, human activity and industry are significant contributors. Industries such as agriculture, fashion, and construction are some of the biggest culprits when it comes to polluting water sources. The discharge of untreated wastewater, the use of harmful chemicals, and the improper management of waste are some of the main ways in which industries contaminate water, leading to adverse effects on both the environment and human health.

Industrial waste

The production of industrial goods generates wastewater that can be contaminated with toxic substances. These substances can include heavy metals such as copper, lead and selenium, which come mainly from the manufacture of cars, mining or exhaust air systems. Other contaminants include hazardous wastes, which are highly flammable and corrosive, and come from construction, demolition, manufacturing, trade and waste treatment processes. Per- and polyfluorinated alkyl compounds (PFAS) are another contaminant, which mainly come from the textile industry, hard chrome plating and extinguishing agents.

The fashion industry, in particular, is one of the biggest polluters, producing around 92 million tonnes of waste annually. Water is polluted throughout the entire production chain, from the runoff of fertilisers from cotton plantations into nearby lakes and rivers, to the dyeing of clothes with toxic chemicals, to the release of fibres and dyes into the wastewater when the product is washed.

The construction industry is also a major contributor to water pollution, with 40% of freshwater pollution attributed to buildings. For example, it takes 5,100 litres of water to produce a single tonne of cement, and 235,000 litres to produce a tonne of steel.

The improper treatment and direct release of hazardous industrial effluents into sewerage drains can cause irreversible damage to the ecosystem, polluting groundwater and other major water bodies, and causing adverse effects on the health of animals and aquatic life. These under-treated effluents can also cause other environmental pollution, such as air and soil pollution.

Agricultural waste

Agriculture accounts for 70% of water withdrawals worldwide and is a major contributor to water pollution. Farms discharge large quantities of agrochemicals, organic matter, drug residues, sediments, and saline drainage into water bodies. This includes pesticides, nitrogen and phosphorus fertilizers, and organic farm wastes, which can contaminate water sources and harm the environment and human health.

One of the main ways agricultural waste pollutes water is through runoff. When it rains, fertilizers, pesticides, and animal waste from farms wash into waterways, carrying nutrients and pathogens such as bacteria and viruses. This nutrient pollution, caused by excess nitrogen and phosphorus in water, is the number one threat to water quality worldwide. It can cause algal blooms, a toxic soup of blue-green algae harmful to people and wildlife.

Another issue is the use of veterinary medicines, such as antibiotics, vaccines, and growth promoters, which can move from farms through water to ecosystems and drinking water sources. The increased use of antibiotics and antifouling agents in aquaculture can also contribute to polluting downstream ecosystems. Additionally, fish excreta and uneaten feeds from aquaculture can diminish water quality.

To mitigate these issues, various measures can be implemented. Buffer strips, or vegetated filter strips at the margins of farms and along rivers, can help decrease pollutant concentrations entering waterways. Integrated farming systems, where crops, livestock, and other resources are managed collectively, can also optimize resource use and reduce pollution. Implementing policies and incentives that promote sustainable and healthy diets, reduce food waste, and minimize environmental impacts can also help address agricultural water pollution.

Sewage and wastewater

Sewage pollution is not just an eyesore; it poses a serious risk to human health, biodiversity, and aquatic life. It can cause a range of health issues, from skin rashes and pink eye to respiratory infections and hepatitis. In addition, sewage can lead to the growth of harmful algal blooms, which deplete oxygen levels in the water, creating "dead zones" where aquatic life cannot survive. These algal blooms can also produce neurotoxins that affect wildlife, including whales and sea turtles.

Wastewater from homes and businesses is typically treated at dedicated facilities before being released back into the environment. However, in some cases, sewage is discharged raw or untreated into rivers and oceans. This can occur due to outdated sewer systems, inadequate infrastructure, or improper disposal of items such as wipes, nappies, and cooking fats, which can cause blockages and flooding.

According to the United Nations, more than 80% of the world's wastewater flows back into the environment without proper treatment or reuse. This untreated wastewater contains harmful pollutants such as pathogens, phosphorus, nitrogen, heavy metals, and toxic chemicals. In the United States alone, sewage treatment systems release over 850 billion gallons of untreated wastewater annually.

The impact of sewage and wastewater pollution extends beyond the immediate ecological consequences. It also affects water users, including swimmers and those engaged in water-based activities. Poor water quality increases the risk of contracting illnesses, with thousands of people falling sick each year due to contaminated water. Therefore, addressing sewage and wastewater pollution is crucial to safeguarding both the environment and public health.

Marine pollution

The fashion industry, for example, produces around 92 million tonnes of waste annually, polluting water sources throughout its production chain. From the runoff of fertilisers from cotton plantations to the toxic chemicals used in dyeing clothes, the industry has a substantial impact on water pollution.

The construction industry is another contributor to marine pollution, often overlooked by environmentalists. The production of building materials such as cement, steel, and lumber requires a significant amount of water and can result in water pollution.

Agricultural activities also play a significant role in marine pollution. The use of fertilisers, pesticides, and insecticides in agriculture can contaminate water sources, especially during intensive irrigation when these chemicals are washed away into watercourses by rain. Additionally, animal waste from farms and livestock operations can introduce waterborne pathogens, such as bacteria and viruses, into waterways.

Furthermore, industrial activities generate large amounts of wastewater that can be contaminated with toxic substances. This includes petroleum products, heavy metals, hazardous wastes, and sediments containing non-degradable toxins. Improper treatment and discharge of industrial wastewater can lead to irreversible damage to marine ecosystems and adverse effects on human health.

It is important to note that the impact of marine pollution is not limited to environmental damage. Contaminated water can cause illnesses, and in 2015, it was responsible for 1.8 million deaths, according to a study published in The Lancet. Therefore, it is crucial to address marine pollution through proper wastewater treatment, reduced usage of harmful chemicals, and stricter environmental regulations.

Construction

One of the main ways construction sites contribute to water pollution is through the creation of stormwater runoff. When it rains, stormwater can wash over loose soil and various materials and products stored outside on a construction site. As it flows, stormwater can pick up and carry pollutants such as sediment, chemicals, and other debris into nearby waterways. This type of nonpoint source pollution is challenging to regulate as there is no single identifiable culprit. Sediment pollution, in particular, has led to fines for several UK housebuilders.

Another source of pollution from construction is fuel and chemical spillages. The use of machinery and the requirement to store fuel on-site can lead to accidental spillages if fuel tanks are not appropriately sited. Chemicals used in processes like cement-making and solvents can also be released accidentally, harming the environment and watercourses. Diesel spillages, for example, can quickly spread and kill fish, plant life, and invertebrates in streams and rivers. They can also affect the potability of water, rendering it unsafe for drinking.

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