Human Activities Polluting Surface Water Sources

Surface water pollution is a serious issue that poses a threat to global drinking water supplies and the aquatic ecosystems that depend on them. As a universal solvent, water easily dissolves substances, making it highly susceptible to pollution. Sources of surface water pollution include agricultural runoff, sewage and wastewater, oil pollution, and radioactive substances. Oil spills, while often accidental, are a major contributor, as are industrial sites that produce toxic chemicals and lack proper waste management systems. Other sources include sediment from soil erosion, chemical dumping, algal blooms, and heat from power plants, which reduces the water's capacity to hold dissolved oxygen. With overwhelmed sewage treatment systems, billions of gallons of untreated wastewater are released into surface waters each year.

Oil and chemical spills

The release of oil and chemicals into coastal waterways has severe environmental and economic impacts. Spills can kill wildlife, destroy habitats, and contaminate food resources in the marine food chain, such as seafood. They can also force the closure of fisheries, drive away tourists, and disrupt navigation routes, causing long-lasting harm to coastal communities that depend on these resources for survival and commerce.

Oil spills are challenging to clean up, and even with advanced technologies like booms, skimmers, and in-situ burning, it is impossible to remove 100% of the spilled oil. The cleanup efforts themselves can sometimes cause additional harm to sensitive habitats, as seen in the aftermath of the Exxon Valdez oil spill in 1989.

Chemical spills are another significant concern. Industries and industrial sites produce toxic chemicals and waste, and improper waste disposal or leaks from storage tanks can lead to groundwater and surface water contamination. Sources of chemical contaminants include poorly designed or maintained sewage systems, industrial waste disposed of in landfills or lagoons, mining and petroleum production, and leaking underground storage tanks.

To address oil and chemical spills, it is crucial to identify the type and extent of the spill, as well as its potential impact on the local environment. Glider technology and high-frequency radar systems help track and predict the movement of spills, aiding in cleanup and restoration efforts. Additionally, legislation like the Oil Pollution Act of 1990 holds those responsible for oil spills accountable for the financial burden of cleanup and restoration.

Poor wastewater treatment

Inadequate wastewater treatment has far-reaching consequences for climate resilience, aquatic biodiversity, and food and water security and access. It can lead to habitat loss and even extinction, as untreated wastewater introduces harmful substances into the water, damaging ecosystems and disrupting the natural functioning of ecosystems. For example, sediment (such as silt) from soil erosion or construction can be carried into water bodies by surface runoff, upsetting the ecological balance. It can also disrupt the reproductive cycles of fish and, when it settles, smother bottom-dwelling organisms.

Furthermore, wastewater treatment is particularly neglected in developing countries, where only a small fraction of domestic and urban wastewater is treated before release. This is due in part to higher population and economic growth and a lack of wastewater management systems. The greatest increases in exposure to pollutants are expected in low- and lower-middle-income countries, primarily in Africa.

The agricultural sector, which is the biggest consumer of global freshwater resources, is a significant contributor to water pollution. Agricultural pollution is the leading cause of contamination in rivers and streams in the United States and has a severe impact on wetlands and lakes as well. The increased use of chemical fertilizers and pesticides, along with untreated wastewater in irrigation, pollutes both groundwater and surface water.

Industries and industrial sites are also major contributors to water pollution, as many still discharge waste directly into watercourses. While regulations exist, some industrial sites lack proper waste management systems, releasing toxic chemicals and pollutants into water sources.

Industrial waste

The nature of the contaminants present in industrial wastewater depends on the type of factory and industry. For example, the paper and pulp industry releases suspended solids and highly organic materials, while textile industries generate compounds such as heavy metals, surfactants, bleaching agents, and alkaline bases. The food products industry is also a major contributor to toxic wastes and organic pollutants.

In the United States, wastewater treatment facilities process about 34 billion gallons of wastewater per day, reducing pollutants such as pathogens, phosphorus, nitrogen, heavy metals, and toxic chemicals in industrial waste. However, the country's aging and easily overwhelmed sewage treatment systems also release more than 850 billion gallons of untreated wastewater each year.

Industrial activities, such as manufacturing, mining, and waste disposal, are some of the worst water polluters. For example, the now-defunct Diamond Alkali Co. in Newark, New Jersey, polluted the Passaic River, a drinking water source for millions, with chemicals. Similarly, various industries have dumped about 600 million pounds of toxic substances, including ammonia and nitrates, into the Ohio River, which provides drinking water to nearly 3 million people.

The effects of industrial water pollution are devastating to the environment and human health. It destroys aquatic life, reduces reproductive ability, and contaminates drinking water sources, leading to the spread of diseases.

Agricultural runoff

Farming and livestock production use about 70% of the earth's surface water supplies, and agriculture is the leading cause of water degradation. In the United States, agricultural pollution is the top source of contamination in rivers and streams, the second-biggest source in wetlands, and the third main source in lakes. The National Water Quality Assessment shows that agricultural runoff is the leading cause of water quality impacts on rivers and streams.

Pesticides are organic pollutants that are often released into surface water, groundwater, and even seawater through agricultural runoff. While the concentration of pesticides in water may be low, prolonged exposure can cause serious damage to aquatic life, with fish being particularly vulnerable. Pesticides can be removed from water through various methods such as adsorption, filtration, sedimentation, and microbial degradation, which is considered the most reliable technique.

To minimize the impact of agricultural runoff on water quality, farmers can implement conservation practices such as contour strip cropping, which reduces erosion and runoff. Nutrient management practices, such as targeting fertilizer and manure application through soil testing and timing applications, can also help to minimize runoff. Storing livestock manure in protected areas, such as lagoons or covered stockpiles, can further reduce the risk of runoff. Additionally, using drip irrigation instead of furrow irrigation allows for better control of the amounts of pesticides and nutrients added to irrigation water.

Radioactive substances

Radioactive contamination is more prevalent in groundwater than surface water. However, nuclear calamities, nuclear power plants, and the dumping of radioactive waste are major sources of anthropogenic radioactive surface water pollution. Radioactive isotopes used in industries and scientific laboratories are minor sources. Radioactive waste dumped into surface water bodies can also cause water pollution. Atmospheric deposition (both dry and wet) of cosmogenic radionuclides can also add radioactive nuclei to surface water.

The production of nuclear weapons and energy from fissionable material is one potential source of radioactive surface water pollution. Mining for uranium is another. Uranium mining activities pollute surface and groundwater. Nuclear power plants placed in coastal regions add to the radiological contaminants in the marine water by releasing atomic waste. Water is also used as a coolant in these powerhouses, which then gets contaminated.

Radioactive elements can be introduced into water via medical treatments, including radioactive iodine used to treat thyroid disorders. They can also be unearthed during oil and gas drilling or any industrial activities that involve cracking into bedrock where radioactive elements naturally exist. Radioactive iodine is used in medical equipment such as X-rays and MRI machines, which expose patients to low levels of radiation.

Radioactive contaminants in water are a serious problem for people, animals, and the environment. They can make people sick, make the soil inhospitable to plants, and cause mutations in animals. Radioactive contaminants can be difficult to remove from water, but some effective treatment options include reverse osmosis, ion exchange, and carbon filtration. Combining multiple treatment technologies is more effective than using a single method.

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