Water Pollution: Understanding The Sources And Their Impact

Water pollution is a pressing issue that endangers the health of millions worldwide. It is caused by a variety of factors, including toxic waste, petroleum, industrial waste, oil spills, agricultural practices, and sewage. These contaminants find their way into our rivers, reservoirs, lakes, and seas, rendering the water unsafe for human use and disrupting aquatic ecosystems. The release of chemicals, waste, plastic, and other pollutants into water supplies has severe consequences for both human health and the environment. With water being a vital resource, addressing water pollution is crucial for safeguarding public health and ensuring the sustainable development of societies.

Industrial waste

Industrial solid waste can be solid, liquid, or gases held in containers, and it is divided into hazardous and non-hazardous waste. Hazardous waste may result from manufacturing or other industrial processes, such as cleaning fluids, paints, or pesticides. Non-hazardous waste does not meet the EPA's definition of hazardous waste and is not municipal waste.

The effects of industrial water pollution are devastating to people, animals, fish, and birds. Polluted water is unsuitable for drinking, recreation, agriculture, and industry. It also diminishes the aesthetic quality of lakes and rivers and destroys aquatic life and reduces its reproductive ability.

Some of the most common sources of industrial water pollution include:

• Mining and smelting operations, which contaminate water with heavy metals and other pollutants.
• Manufacturing and waste disposal companies, which contaminate water with arsenic, lead, mercury, and chromium.
• Chemical dumping from factories, farms, and cities, which can cause eutrophication of water.
• Dry cleaning fluids, which have contaminated groundwater supplies across the United States with PCE (perchloroethylene or tetrachloroethylene), a suspected carcinogen.
• Food products industry, which can contain toxic wastes and organic pollutants.
• Small-scale industries that cannot afford investments in pollution control equipment.

To address industrial water pollution, the Ministry of Environment in each province develops policies and regulations, conducts stakeholder consultations, administers authorizations, and performs compliance activities to regulate the discharge of solid, liquid, and gaseous wastes from industrial sources. Technologies have also been developed to separate and recycle various industrial wastes.

Agricultural processes

Agriculture is a major contributor to water pollution, accounting for 70% of water withdrawals worldwide. Farms discharge large quantities of agrochemicals, organic matter, drug residues, sediments, and saline drainage into water bodies. Over the last two decades, a new class of agricultural pollutants has emerged: veterinary medicines (such as antibiotics, vaccines, and growth promoters) that move from farms into ecosystems and drinking water sources.

Farms also contribute to water pollution through the use of veterinary medicines, such as antibiotics and vaccines. These drugs can leave residues in water bodies, potentially impacting aquatic ecosystems and downstream drinking water sources. Additionally, the use of fungicides and anti-fouling agents in aquaculture has increased, which may further contribute to polluting downstream ecosystems.

Sediment is another leading pollutant in rivers and streams, and agricultural practices can be a significant source of this. Pesticides, such as atrazine, are widely used in agriculture and are often detected in surface water, posing risks to aquatic life and drinking water supplies.

To mitigate these issues, proper management of agricultural practices is crucial. This includes implementing measures to reduce the risk of water pollution from fertilizers and pesticides, such as limiting and optimizing their use and establishing protection zones along water bodies. Efficient irrigation schemes can also significantly reduce the migration of fertilizers and pesticides into nearby water sources.

Sewage treatment systems

One of the primary issues with sewage treatment systems is their age and capacity. Many of these systems were built in the 19th and 20th centuries when populations were significantly lower. As a result, the infrastructure is now ageing and struggling to keep up with the increasing volume of sewage generated by growing populations. This is particularly evident in countries like the UK, where the sewage system has reached a crisis point due to years of underfunding and deregulation.

The consequences of inadequate sewage treatment are severe. When sewage systems are overwhelmed, they can release untreated wastewater into nearby water bodies, including rivers, lakes, and oceans. This untreated wastewater contains high levels of nitrogen and phosphorus from human waste, food, soaps, and detergents, leading to nutrient pollution. According to the EPA, the United States' sewage treatment systems release more than 850 billion gallons of untreated wastewater each year, contributing to water pollution.

In addition to ageing infrastructure, sewage treatment systems can also fail due to improper management and maintenance. Septic systems, for example, which are used by approximately 20% of homes in the United States, can become a source of nutrient pollution if not properly maintained. Common causes of septic system failure include ageing infrastructure, inappropriate design, overloading with too much wastewater, and poor maintenance.

The impact of sewage pollution on water quality and human health is significant. Water contaminated with human waste can contain harmful bacteria, viruses, and parasites, leading to diseases such as cholera and typhoid and diarrheal illnesses. It can also affect agricultural yields, ecosystems, and the economy of regions, as contaminated water reduces the oxygen content, leading to a decline in GDP.

To address these issues, significant investments are required to upgrade and expand sewage treatment infrastructure. This includes improving the capacity of treatment plants, implementing enhanced treatment systems, and ensuring proper maintenance and management of septic systems. Additionally, natural solutions, such as planting trees, restoring wetlands, and creating green roofs, can help expand the capacity of sewer systems and prevent stormwater from rushing into sewers, reducing the risk of overflows.

Oil spills and leaks

One of the primary ways oil spills harm marine life is through fouling or oiling. This occurs when oil physically coats an animal, such as a bird's wings, rendering it unable to fly, or a sea otter's fur, compromising its insulating properties and putting it at risk of hypothermia. Oil spills also damage sensitive environments like beaches, mangroves, and wetlands, ruining recreational activities and making seafood unsafe to eat.

The transportation and transfer of oil are major contributors to the risk of oil spills. The process of transporting oil from its source to its final use can involve multiple transfers between ocean tankers, pipelines, trains, and trucks, increasing the likelihood of accidents or leaks. Additionally, individual tanks within ships have limited capacities, and a leak in one compartment can result in significant damage.

Oil spills have been a catalyst for transformative events in pollution control and environmental activism. For example, the 1969 blowout of an offshore oil platform off the coast of Santa Barbara, California, accelerated the development of federal government policies and changed how the government addressed environmental pollution. This event spurred the passage of laws such as the National Environmental Policy Act and the Clean Water Act.

While large oil spills tend to garner more attention, it is important to recognize that consumer activities contribute significantly to oil pollution in our seas. Oil and gasoline drips from cars and trucks, as well as improper disposal of oil, paint, and hazardous chemicals, are major sources of water contamination. Furthermore, natural sources of oil, such as seepage from the ocean floor and eroding sedimentary rocks, also contribute to oil pollution.

The consequences of oil spills can be long-lasting, impacting ecosystems and economies for decades. Effective oil spill response requires scientific expertise and the involvement of government agencies, such as the U.S. Coast Guard and the Environmental Protection Agency (EPA), to oversee and manage the cleanup process.

Natural presence of chemicals

The natural presence of chemicals in water supplies can be a significant health risk. While some chemicals are added to water supplies through human activity, such as industrial waste and pesticides, there are also naturally occurring chemicals that can be harmful.

Arsenic, for example, is a heavy metal that can be found in water supplies. It is a potent toxin and carcinogen, and exposure can lead to serious health issues, including hormone disruption and cancer. Arsenic can leach into water supplies from natural deposits in the Earth's crust, and it is estimated that millions of people worldwide are exposed to unsafe levels of arsenic, primarily through drinking water.

Fluoride is another natural chemical that can be found in groundwater. While fluoride is often added to water supplies to help prevent tooth decay, excessive levels can be harmful. High levels of naturally occurring fluoride in water can lead to a condition known as fluorosis, which can cause dental and skeletal issues. In some parts of the world, high fluoride levels in drinking water are a significant health concern.

Lead is also a naturally occurring chemical that can contaminate water supplies. Lead pipes and plumbing fixtures can leach lead into drinking water, posing a serious health risk, particularly to children and pregnant women. Lead contamination can cause a range of health issues, including brain and nervous system damage, behavioural problems, and learning difficulties.

In addition to these chemicals, mercury is another natural contaminant. Mercury can filter from the Earth's crust into oceans, rivers, and lakes, and it is a potent neurotoxin. Mercury contamination in water supplies can have severe health consequences, including damage to the brain, kidneys, and developing foetuses.

While the natural presence of these chemicals in water supplies can be a concern, it is important to note that human activity can also exacerbate the problem. For example, deforestation can increase mercury levels in water by removing the trees that would otherwise absorb it. Similarly, industrial activities can release heavy metals and other toxins into the environment, which can then find their way into water supplies.

As a result, the natural presence of chemicals in water supplies is a complex issue that requires careful management and treatment to ensure safe drinking water for all.

Frequently asked questions