Natural Water Pollutants: Three Key Ecological Threats

Water pollution is a global issue that poses a threat to human health, the environment, and the economy. While there are many causes of water pollution, three natural sources of water pollution include oil seeps, groundwater contamination, and industrial waste. Firstly, oil seeps occur when oil is naturally released from fractures in the ocean floor, contributing to water pollution. Secondly, groundwater, an essential natural resource, can become contaminated by various pollutants, including pesticides, fertilizers, and waste from landfills. Lastly, industrial waste, in the form of toxic chemicals and pollutants from factories and farms, can find its way into freshwater systems, rendering them unsafe for human consumption and harmful to aquatic life. These natural sources of water pollution highlight the importance of addressing water contamination to protect human health and the environment.

Oil spills and leaks

Oil spills affect not only the ocean but also coastal waters and land. They can harm sea creatures, ruin beaches, and make seafood unsafe to eat. Oil penetrates the plumage of birds and the fur of mammals, reducing their insulating ability and making them more vulnerable to temperature changes and less buoyant in the water. Oil spills can also have negative effects on human health, including respiratory and reproductive problems, liver damage, and immune system issues.

Cleanup and recovery from an oil spill are challenging and time-consuming, often taking weeks, months, or even years. The type of oil spilled, water temperature, and shoreline characteristics play crucial roles in the cleanup process. Additionally, cleanup activities can have unintended consequences, as seen in the Exxon Valdez oil spill, where the use of high-pressure, hot-water hoses caused more damage than the oil itself.

While large oil spills from tankers and platforms often dominate the headlines, it is important to recognize that consumer activities and land-based sources contribute significantly more to oil pollution in our seas. Oil and gasoline drips from cars and trucks, as well as runoff from roads, cities, factories, farms, and rivers, account for a substantial portion of the estimated 1 million tons of oil that enters marine environments annually. Oil pollution is not limited to the ocean; it also affects lakes and reservoirs, as oil disposed of improperly through storm drains can contaminate these water sources.

Industrial waste

Types of Industrial Waste

Industrial solid waste can be solid, liquid, or gaseous and is held in containers. It is divided into hazardous and non-hazardous categories. Hazardous waste results from manufacturing or other industrial processes, and includes commercial products like cleaning fluids, paints, or pesticides discarded by commercial establishments or individuals. Non-hazardous industrial waste does not meet the EPA's definition of hazardous waste and is not municipal waste.

Some specific examples of industrial waste include cafeteria garbage, dirt and gravel, masonry and concrete, scrap metals, trash, oil, solvents, chemicals, weed grass and trees, wood and scrap lumber, and similar wastes.

Effects of Industrial Waste Water Pollution

The effects of 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, destroys aquatic life, and reduces its reproductive ability.

Sources of Industrial Waste Water Pollution

Sources of industrial waste water pollution include factories, manufacturing, mining, and waste disposal companies. For example, the Anaconda Aluminum company in Montana produced manufacturing wastes that contaminated local water sources with lead and chromium.

Preventing and Controlling Industrial Waste Water Pollution

The US Environmental Protection Agency (EPA) has regulations in place to keep people safe from industrial pollution in their drinking water. The EPA also provides resources and tools to address and prevent water pollution, such as the Clean Water Act and the National Pretreatment Program, which controls non-domestic discharges from industrial and commercial sources into municipal sewer systems.

Additionally, the Ministry of Environment in each province regulates the discharges of solid, liquid, and gaseous wastes from industrial sources through policy development, stakeholder consultations, and compliance activities.

Despite these efforts, water pollution from industrial sources remains a significant issue, with hundreds of companies contaminating drinking water for decades, according to EPA data.

Sewage and wastewater treatment

The main goal of sewage and wastewater treatment is to remove contaminants and produce an effluent that can be safely discharged into the environment or reused. This process is crucial as it prevents water pollution from raw sewage discharges. There are two main stages of sewage treatment, known as primary and secondary treatment, and some advanced treatment processes also incorporate a tertiary treatment stage.

Primary treatment involves removing suspended solids from wastewater and aerating it to restore oxygen levels. This step eliminates about 60% of suspended solids. Secondary treatment is more effective, removing more than 90% of suspended solids. It is important to remove these solids as the decay of solid material depletes oxygen, which is essential for aquatic plants and animals.

Sewage can be treated through decentralized or centralized systems. Decentralized systems treat sewage close to its source, using on-site treatment systems such as septic tanks. In contrast, centralized systems collect and transport sewage through a network of pipes and pump stations to a municipal treatment plant. This treatment plant can be a sewage treatment plant (STP) or wastewater treatment plant (WWTP), with the latter being a broader term that can include industrial wastewater treatment.

Both natural and high-tech treatment processes are utilized, depending on the system. Natural treatment processes tend to occupy larger areas and use natural methods, while high-tech options are more compact and mechanized, often employing advanced technologies. However, it's worth noting that some treatment plants may combine these processes, and the interpretation of "high-tech" and "natural" can vary.

Pesticides and fertilisers

Pesticides are designed to control, prevent, kill, reduce or repel pests. They can be made from natural ingredients or synthetic chemicals, and all are toxic to some degree. The toxicity varies, with some pesticides, such as pyrethroids, organophosphates, and fipronil, being highly toxic to aquatic organisms. These chemicals are often found in household and garden products and can be deadly to aquatic life, even in small amounts. Aquatic invertebrates are particularly susceptible, and their loss affects the entire food chain.

Pesticides can enter water sources in several ways. They are often applied directly to agricultural land, non-crop land, and urban areas, and can then seep into water-bearing aquifers below the ground. They can also enter water through the seepage of contaminated surface water, accidental spills and leaks, improper disposal, and injection waste material into wells. Pesticides can also be carried by wind or rain from hard surfaces into storm drains, which then flow into nearby rivers, streams, and oceans.

The solubility of a pesticide is an important factor in its potential to pollute water. Many pesticides are designed to be water-soluble so that they can be applied with water and absorbed by the target. The higher the solubility, the higher the risk of leaching into water sources.

Fertilisers, when overused, can also contribute to water pollution. They can filter through the soil and make their way into groundwater, which is used for drinking water. Even after wastewater treatment, some fertiliser nutrients remain, and these can enter waterways and contribute to environmental degradation.

To prevent pesticides and fertilisers from polluting water sources, it is important to use them correctly and sparingly. They should only be applied under the right weather conditions, with low wind speeds and no rain or snow forecast. Proper disposal of these products is also essential to avoid contamination of water sources.

Radioactive substances

Radioactive elements are naturally found in the earth's crust. Uranium, thorium, and actinium are three NORM (Naturally Occurring Radioactive Material) series that contaminate water resources. Radium, a descendant of the NORM series, is one of the most radiotoxic elements found in aquatic systems. It can penetrate groundwater through aquifer rock dissolution, the decay of uranium and thorium, or desorption processes.

Anthropogenic sources of radioactive water pollution include nuclear weapon testing, nuclear disasters, nuclear power plants, and the dumping of radioactive waste. Nuclear reactors produce radioisotopes, such as Cobalt-60 and Iridium-192, used in radiotherapy and industrial applications. They also generate radioactive waste, including Strontium-90 and Caesium-137. Mining activities for uranium and thorium further contribute to surface and groundwater pollution.

Radioactive contamination is more prevalent in groundwater than surface water due to its proximity to radioactive elements in rocks. Atmospheric deposition, volcanic activity, and industrial activities can also release radioactive gases that contribute to water pollution. Public drinking water systems employ various methods, including filtration and regular testing, to ensure that the water supplied to consumers meets all applicable standards and is safe for consumption.

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