Human Activities: Rivers' Pollution Culprit

Water pollution is a pressing issue that affects the lives of one in every three people on the planet, according to the United Nations. The planet's rivers, reservoirs, lakes, and seas are being inundated with chemicals, waste, plastic, and other pollutants. This has rendered nearly half of the rivers and streams in the United States polluted and unfit for swimming, fishing, or drinking. While there are natural causes of water pollution, such as mercury filtering from the Earth's crust, human activity is the predominant cause of poor water quality. This includes industrial chemical dumping, sewage, and agricultural runoff.

Farming and agriculture

Agriculture is a major contributor to river pollution, with farming practices causing significant damage to aquatic ecosystems and freshwater sources. This is particularly evident in the US, where agriculture is the primary source of pollution in rivers and streams, the second-largest source in wetlands, and the third in lakes.

Farming activities introduce a range of pollutants to water bodies, including agrochemicals, organic matter, drug residues, sediments, and saline drainage. The use of nutrient-rich materials and fertilisers by farmers is a notable issue. While these enhance soil quality, they can be washed into rivers during rainfall, leading to nutrient pollution in the form of nitrates and phosphates. This type of pollution poses risks to human health, with high nitrate levels linked to "blue baby syndrome", a potentially fatal condition in infants.

The discharge of farm waste and the increased use of antibiotics and other medications in farming are also concerning. These substances can contaminate water sources, impacting both ecosystems and drinking water. For instance, fish excreta and uneaten feed from aquaculture reduce water quality and, along with antibiotics, can pollute downstream ecosystems. Furthermore, the use of heavy machinery in farming can lead to oil spills and the discharge of pollutants from tyre and brake wear, further contributing to river pollution.

To address these issues, regulatory bodies work with farmers to ensure compliance with rules such as the UK's Farming Rules for Water. These rules aim to minimise the risk of pollution from nutrient applications and livestock management. Techniques like riparian buffer strips and constructed wetlands are also promoted as cost-effective ways to reduce pollutants entering surface water bodies. Integrated farming systems, where various agricultural components are collectively managed, can enhance resource efficiency and reduce pollution by optimising waste.

Industrial waste and chemicals

Chemical waste from industrial sites, construction projects, and factories can contaminate water sources in several ways. Rainwater can wash toxic chemicals directly into rivers, streams, and lakes. Additionally, improper waste disposal methods, such as illegal dumping near water sources, can lead to harmful chemicals seeping into the soil and contaminating groundwater, which eventually flows into rivers and other water bodies.

The manufacturing, mining, and waste disposal industries are among the worst offenders when it comes to water pollution. For example, the Anaconda Aluminum company in Montana contaminated local water sources with lead and chromium, while Gulf States Utilities in Louisiana discharged benzene and other chemicals into marshlands. In another instance, the now-defunct Diamond Alkali Co. in New Jersey polluted the Passaic River, a drinking water source for millions, with chemicals used to make Agent Orange.

The transportation and storage of oil and its derivatives are also susceptible to leakage, which can have detrimental effects on water resources. Furthermore, the burning of fossil fuels like coal and petroleum contributes to rising global temperatures, which heat up water bodies, reducing their oxygen content and endangering aquatic life.

The impact of industrial waste and chemicals on rivers is not limited to the environment. In North Carolina, residents living near coal-fired power plants were alerted to elevated levels of chromium-6 and other chemicals in their water supply, forcing many to rely on bottled water for essential tasks like drinking, cooking, and maintaining personal hygiene. This illustrates how industrial pollution directly affects the lives and health of people living in affected areas.

Sewage and wastewater treatment

Domestic sewage, industrial sewage, and storm sewage are the three main types of wastewater. Domestic sewage, also known as sanitary sewage, carries used water from households. Industrial sewage, on the other hand, is water used in manufacturing or chemical processes. Storm sewage refers to surface runoff that is typically discharged into streams or rivers. Heavy rainfall can overwhelm sewage systems, causing overflow and the release of untreated or partially treated sewage into nearby rivers. This is particularly common in older cities with outdated infrastructure.

To address sewage pollution, it is crucial to invest in infrastructure upgrades and improve treatment plants to prevent raw sewage discharges. Implementing advanced treatment technologies and enhancing filtration processes can minimize the presence of harmful bacteria and pollutants in treated sewage. Additionally, stringent regulations and enforcement are necessary to ensure that wastewater treatment plants comply with standards. Governments and regulatory bodies play a vital role in monitoring and enforcing these regulations.

Public awareness and education about the impact of sewage pollution on river ecosystems are also essential for driving long-term change. Individuals can make conscious choices to reduce their impact on river pollution and advocate for better sewage management practices. Proper disposal of domestic and small business waste can significantly reduce sewage pollution. By working together and investing in the right infrastructure, we can protect our rivers and ensure clean water for future generations.

In summary, sewage and wastewater treatment are critical components of river pollution prevention. Upgrading infrastructure, improving treatment processes, enforcing regulations, and raising public awareness are key steps towards minimizing the impact of sewage pollution on our precious river ecosystems.

Urban and transport runoff

Sources of these pollutants include vehicular transportation-related activities, such as oil spills, tyre and brake wear, and the improper disposal of vehicle fluids. Atmospheric deposition, metallic building envelopes, and litter are also major contributors. These pollutants can have detrimental effects on aquatic ecosystems, leading to the decline of fish and shellfish populations and the contamination of drinking water supplies.

Stormwater runoff is particularly problematic in areas where land use has shifted from rural to urban activities. In Washington state, for example, stormwater runoff is responsible for 30% of water pollution, with one-third of the state's polluted waters being impacted. This has led to the closure of thousands of acres of shellfish and swimming beaches and has harmed local businesses.

To mitigate stormwater runoff pollution, it is essential to implement source controls and other effective pollution mitigation tools. Individuals can play a crucial role by properly maintaining their vehicles, recycling used vehicle fluids, and avoiding dumping waste into storm drains. Additionally, choosing to walk, bike, or use public transportation instead of driving can help reduce vehicular pollution.

While progress has been made in understanding and managing urban and transport runoff, it is an ongoing process. The rapid advancement of clean manufacturing and pollution control technologies means that data on stormwater quality is constantly evolving, and new substances of potential concern are continually being introduced into the environment.

Abandoned metal mines

The impact of abandoned metal mines on river pollution is long-lasting, with pollution continuing for hundreds of years unless proper action is taken. In 2023, the UK Parliament approved a legally binding target to halve the length of rivers polluted by abandoned metal mines by 2038. This target will be achieved through the Water and Abandoned Metal Mines (WAMM) Programme, a partnership between the Environment Agency, the Coal Authority, and Defra. The WAMM Programme currently operates four successful mine water treatment schemes, improving water quality in more than 30 km of rivers, with a fifth scheme set to begin operating in September 2024.

One example of the devastating effects of abandoned metal mines on river pollution is the Wheal Jane mine in Cornwall. After the mine closed in 1991 and the water pumps were switched off, the mine workings filled with rainwater, leading to the release of 50 million litres of extremely acidic water in a single day, turning the Carnon River and Fal Estuary orange and polluting them with harmful metals. The government built a system to treat the mine water, which is now managed by the Coal Authority as part of the Defra-funded WAMM Programme. This system has prevented 800 tonnes of harmful metals from polluting the environment in a typical year.

To address river pollution from abandoned metal mines, it is crucial to capture the metals in mine water treatment schemes before they enter rivers. Nature-based solutions, such as the Force Crag treatment scheme, use natural chemical and biological reactions to capture metals as the mine water passes through ponds containing compost and woodchips. These approaches have lower whole-life cycle costs and a smaller carbon impact than traditional treatment methods.

In conclusion, abandoned metal mines are a significant source of river pollution, particularly in certain regions of Britain. The issue of metal mine pollution is long-lasting and requires proactive measures to prevent and mitigate its impacts. By implementing effective treatment schemes and nature-based solutions, it is possible to improve water quality and reduce the harmful effects of abandoned metal mines on our rivers and aquatic ecosystems.

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