Water Pollution: Environmental Impact And Concerns

Water pollution is a pressing issue that poses significant risks to both human health and the environment. It occurs when harmful substances contaminate bodies of water, including rivers, lakes, oceans, and groundwater, rendering them unsafe and toxic. The main sources of water pollution are human activities such as industrial waste, agricultural runoff, sewage discharge, and urban stormwater runoff. These activities introduce contaminants like chemicals, waste, and microorganisms into water sources, degrading water quality and harming aquatic life. Water pollution has severe consequences, including the destruction of aquatic ecosystems, the spread of waterborne diseases, and a negative impact on drinking water resources. It is essential to address this issue through proper waste management, reduced usage of single-use plastics, and the implementation of sustainable practices to protect the environment and ensure access to clean water for all.

Sewage and wastewater

Wastewater also includes stormwater runoff, which occurs when rainfall washes road salts, oil, grease, chemicals, and debris from impermeable surfaces into our waterways. According to the United Nations, more than 80% of the world's wastewater flows back into the environment without proper treatment or reuse, and in some undeveloped countries, this figure exceeds 95%.

Wastewater introduces a toxic mix of contaminants, including pathogens, pharmaceuticals, microplastics, heavy metals, and endocrine disruptors, which threaten food and water security and harm marine species. Even properly treated sewage can have drawbacks. For instance, microscopic plastic fibres released from certain clothes during washing can pass through wastewater treatment plants and enter marine ecosystems, causing harm to animals and disrupting the food chain.

The improper disposal of sewage and wastewater can have severe consequences for both human and environmental health. If sewage is only partially treated before disposal, it can contaminate water sources and harm aquatic life. Leaking or flooding can cause untreated sewage to enter rivers and other water sources, leading to pollution and the spread of diseases such as E. coli, diarrhoea, and hepatitis A.

Furthermore, sewage and wastewater contribute to eutrophication, a process where excessive nutrients in a body of water cause dense plant growth and deplete oxygen levels, leading to the death of animal life. This results in the creation of "dead zones" where aquatic life cannot survive due to oxygen depletion.

Overall, sewage and wastewater are significant contributors to water pollution, and proper treatment and disposal are crucial to mitigate their environmental and health impacts.

Oil spills

The magnitude of harm caused by an oil spill depends on several factors, including the amount and type of oil, location, season, weather, and the effectiveness of clean-up operations. Oil spills can result in injuries to animals, loss of habitat, and impacts on local economies and recreation.

Injuries to Animals

Loss of Habitat

Oil discharged into the environment can harm habitats such as wetlands and oyster reefs. Habitat losses may alter migration patterns, disrupt life cycles, and result in the erosion of shorelines.

Impacts on Local Economies and Recreation

Radioactive waste

High-level waste includes used nuclear fuel from nuclear reactors and waste generated from reprocessing spent nuclear fuel. While defence-related activities generate most of the United States' liquid high-level waste, the majority of spent nuclear fuel originates from commercial nuclear power plant reactors. Currently, most high-level waste is stored at the site where it was produced.

Transuranic waste refers to man-made radioactive elements with an atomic number of 92 (uranium) or higher. This waste primarily comprises common items such as rags, tools, and laboratory equipment contaminated during the early era of nuclear weapons research and development. Transuranic waste is stored at various federal facilities across the United States, with waste created as part of defence programs ultimately being disposed of at the Waste Isolation Pilot Plant (WIPP) in New Mexico.

Uranium or thorium mill tailings are radioactive wastes remaining after the mining and milling of uranium or thorium ore. These tailings are stored at production sites in specially designed ponds called impoundments.

The long-term persistence of radioactive waste in the environment poses significant challenges for its disposal. Radioactive waste can contaminate groundwater, surface water, and marine resources, threatening human health and the environment. It can enter water bodies through accidental releases or improper disposal, as seen in the case of the Fukushima Daiichi nuclear power plant in Japan, where contaminated water continues to be released into the ocean.

Eutrophication

The consequences of eutrophication include:

• Harmful algal blooms: Eutrophication can lead to dense blooms of noxious, foul-smelling phytoplankton that reduce water clarity and harm water quality. These algal blooms can limit light penetration, reducing the growth and causing die-offs of plants in littoral zones, as well as lowering the success of predators that need light to catch prey.
• Tainted drinking water supplies: Algal blooms can produce toxins that are harmful to humans, wildlife, and domestic animals. These toxins can contaminate drinking water supplies, posing significant public health risks.
• Degradation of recreational opportunities: Eutrophication can create "dead zones" where there is a lack of oxygen, making these areas uninhabitable for most organisms. This can negatively impact recreational activities such as swimming, boating, and fishing.
• Hypoxia and anoxia: When the dense algal blooms eventually die, microbial decomposition severely depletes dissolved oxygen, creating hypoxic or anoxic "dead zones". These zones can affect lucrative commercial and recreational fisheries worldwide.
• Acidification: The decomposition of algae by bacteria produces large amounts of carbon dioxide, which can lead to ocean acidification. This can slow the growth of fish and shellfish and prevent shell formation in bivalve mollusks, impacting commercial fisheries.
• Changes in aquatic community structure: Eutrophication can lead to major changes in the structure of aquatic communities, including shifts in species composition and dominance.
• Economic impacts: Eutrophication can have significant economic impacts on industries such as commercial shellfisheries, recreational fisheries, and tourism.

Microplastics

The effects of microplastics on the environment are still being studied, but it is clear that they have a negative impact on marine life and may also affect human health. It is important to reduce, reuse, and recycle plastic to help minimise the impact of microplastics on the environment.

Frequently asked questions