Water Pollution: A Historical Perspective On Its Origins

Water pollution is the contamination of water bodies such as rivers, oceans, lakes, and groundwater, which can be harmful to human health and the environment. It is usually a result of human activities, with more than 80% of the world's wastewater flowing back into the environment without being treated or reused. Water pollution can come from various sources, including sewage discharges, industrial activities, agricultural activities, and urban runoff, which can lead to the spread of water-borne diseases and the degradation of aquatic ecosystems. Oil spills, industrial waste, and plastic pollution are some of the major contributors to water pollution, along with untreated sewage and stormwater runoff carrying chemicals and debris into waterways.

Industrial waste

In the United States, wastewater treatment facilities process billions of gallons of wastewater daily, reducing pollutants such as heavy metals and toxic chemicals before discharging the treated water back into waterways. However, aging and overwhelmed sewage systems also release billions of gallons of untreated wastewater annually. Industrial wastewater contains specific chemical compounds, with toxic wastes and organic pollutants traced to the processing of industrial chemicals and the food products industry.

The environmental impact of industrial waste is devastating, rendering water unsuitable for drinking, recreation, agriculture, and industry. It also destroys aquatic life and reduces its reproductive ability. The effects of water pollution extend beyond the ecological, posing a hazard to human health as well. Dry cleaning fluids, for instance, have contaminated groundwater supplies across the United States, with PCE (perchloroethylene or tetrachloroethylene) being a suspected carcinogen that must be removed from drinking water.

While environmental regulations, such as the Clean Water Act, have been implemented to address water pollution, compliance and enforcement remain challenging. In emerging countries, the rapid growth of industrial plants has outpaced the development of environmental policies, resulting in the illegal discharge of wastewater. Even in the United States, industrial facilities often exceed their permitted pollution levels, with over 40% of American waterways unsafe for swimming and fishing.

The sources of industrial wastewater are diverse, ranging from oil and gas to mining and chemical manufacturing. Food and beverage processing industries also contribute significantly to industrial wastewater. The water used in production processes becomes polluted and requires proper treatment before discharge. However, small-scale industries often lack the financial resources to invest in pollution control equipment, exacerbating the problem.

Sewage and wastewater

Sewage contains a variety of harmful substances, including chemicals, bacteria, and pathogens. Human waste, food scraps, and the use of certain soaps and detergents, herbicides, pesticides, hormones, medications, paints, and solvents contribute to this. When released into water bodies without proper treatment, sewage can have detrimental effects. For example, in the United States, an estimated 3.5 million people annually contract health issues such as skin rashes, pink eye, respiratory infections, and hepatitis from sewage-laden coastal waters. The germs and pathogens in sewage can linger even after the odour has dissipated, causing various illnesses, especially in young children, the elderly, and those with pre-existing health conditions.

Wastewater treatment facilities play a crucial role in mitigating sewage pollution. In the United States, these facilities process approximately 34 billion gallons of wastewater daily, removing pollutants such as pathogens, phosphorus, nitrogen, heavy metals, and toxic chemicals. However, ageing infrastructure and overwhelmed systems can lead to the release of untreated wastewater. The EPA estimates that more than 850 billion gallons of untreated wastewater are discharged annually in the United States.

Septic systems are also a concern. In the United States, approximately 20% of homes rely on septic systems for local wastewater treatment. However, when improperly managed, these systems can release elevated levels of nitrogen and phosphorus into local water bodies or groundwater. Septic system failures can occur due to ageing infrastructure, inappropriate design, overloading, and poor maintenance.

To address sewage and wastewater pollution, it is essential to invest in upgrading and maintaining infrastructure. This includes expanding natural areas, such as planting trees, restoring wetlands, and creating green roofs, to reduce stormwater runoff and increase the capacity of sewer systems. Additionally, strong notification programs are necessary to alert the public about potential dangers from raw sewage releases, and conservation efforts must collaborate with the human health sector to address the global sanitation crisis effectively.

Oil spills

Cleanup and recovery from an oil spill are challenging and expensive. Physical cleanups can be very costly, and even with advanced technology, it is impossible to remove 100% of the spilled oil. The cleanup process must be carefully executed to avoid causing additional harm, as seen in the aftermath of the Exxon Valdez oil spill in 1989, where the use of high-pressure, hot-water hoses caused more damage than the oil itself.

To address oil spills, it is essential to reduce oil pollution through safe disposal methods and proper maintenance of vehicles and equipment. The Oil Pollution Act of 1990 established that those responsible for oil spills can be held accountable for the cleanup and restoration costs. This process, known as Natural Resource Damage Assessment (NRDA), involves federal, state, and tribal agencies working together with the responsible party to select restoration projects with input from the public.

Agricultural activities

Agriculture is a major contributor to water pollution. Farms discharge large quantities of agrochemicals, organic matter, drug residues, sediments, and saline drainage into water bodies. The use of pesticides and fertilizers in agriculture can contaminate both groundwater and surface water, as can organic livestock waste, antibiotics, silage effluents, and processing waste from plantation crops.

Pesticides, fertilizers, and animal waste from farms and livestock operations wash nutrients and pathogens (such as bacteria and viruses) into waterways. Nutrient pollution, caused by excess nitrogen and phosphorus in water or air, is the number-one threat to water quality worldwide and can cause algal blooms, a toxic soup of blue-green algae that can be harmful to people and wildlife.

The intensification of agriculture has led to increased soil erosion, salinity, and sediment loads in water, as well as the excessive use or misuse of agricultural inputs such as fertilizers to increase productivity. The use of antibiotics and other veterinary medicines in livestock farming has also emerged as a new class of agricultural pollutants, contributing to the pollution of downstream ecosystems and drinking water sources.

In addition, aquaculture, or fish farming, has seen tremendous growth, particularly in Asia. Fish excreta and uneaten feeds from aquaculture diminish water quality and, along with the increased use of antibiotics and other chemicals, can pollute aquatic ecosystems.

To address these issues, organizations like the Food and Agriculture Organization of the United Nations (FAO) work with countries and other organizations to monitor, control, and mitigate pollution loads from agricultural activities. The right policies and incentives can also encourage more sustainable practices and reduce food waste, thereby minimizing the environmental impacts of agriculture.

Urban runoff

One example of the consequences of urban runoff can be observed in Southern California. On many beaches at the mouth of a waterway, urban runoff carries trash, pollutants, excessive silt, and other wastes, posing moderate to severe health hazards. The pollutants in the water can also increase stream temperatures, harming fish and other organisms.

To address the issue of urban runoff, it is essential to implement effective flood prevention methods and improve water quality monitoring. This can include increasing the number of flood drains in high-risk areas and regularly testing water quality to identify problems early. Additionally, individuals can contribute by reducing their plastic consumption, properly disposing of chemicals and oils, and maintaining their vehicles to prevent leaks.

In summary, urban runoff is a significant contributor to water pollution, and its impacts can be mitigated through a combination of improved infrastructure, early detection, and individual efforts to reduce pollutant runoff.

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