Water pollution

Published on 05 Apr 2025

Water pollution is the pollution of water bodies with dangerous substances, such as rivers, lakes, oceans, groundwater, and even aquifers. This pollution has the potential to have serious consequences for aquatic ecosystems, wildlife, and human health.

Causes of Water Pollution

• Industrial Discharges: Industries discharge chemicals, toxic substances and wastewater into water bodies.

• Example: According to data presented to UK High Court, Water companies discharged raw sewage into rivers and seas via their storm overflows more than 300,000 times last year.

• Agricultural Runoff: Nutrients like nitrogen and phosphorus seep into water bodies because of overuse of fertilizers in agriculture. The runoff of nutrients may result in eutrophication.

• Example: According to FAO reports, In the European Union, 38 percent of water bodies are significantly under pressure from agricultural pollution.

• Mining Activities: Mining activities have the potential to discharge sediments and heavy metals into adjacent water bodies.

• Example: Coal mining threatens peoples access to water in Mpumalanga, South Africa

• Oil Spills: Oil spills from transportation, industrial activities, etc. result in the release of large quantities of oil into water bodies.

• Example: Oil spill in Chennai during cyclone Michaung

• Volcanic Eruptions: Materials erupted from volcano also pose a threat to the health of the water bodies.

Impacts of Water Pollution

• Harm to Aquatic Life: Toxins, heavy metals, and things that deplete oxygen can cause disease or death to fish, invertebrates etc. also upsetting food systems and decreasing biodiversity.

• Example: Pollution in Dal Lake has badly affected the Schizothorax fish harvest and has destroyed the breeding grounds of the native fish.

• Eutrophication: Pollution from agricultural runoff and wastewater will lead to eutrophication. This may result in high algal growth and decline in fish populations.

• Example: Blue-Green algae bloom in Lake Lough Neagh

• Waterborne Diseases: Contaminated water harbour bacteria, viruses, etc. leading to several diseases.

• Example: Cholera death in Zambia

• Drinking Water Contamination: Heavy metals, industrial pollutants, and pesticides can contaminate drinking water supplies, causing health risks to human populations.

• Example: A study by the CPCB reported that 276 districts in India have groundwater contaminated with fluoride, arsenic, and nitrate beyond the permissible limits.

• Bioaccumulation and Biomagnification: Pollutants that are accumulated in an organism can reach higher concentrations in organisms higher up the food chain.

• Example: DDT, which enters the human body through the food chain can get deposited as adipose tissues, which when oxidized, release toxins into the body. This affects neurological development, reproductive health etc.

• Impact on Industries: Businesses that depend on clean water, like tourism and fishing, may experience financial losses as a result of water contamination.

• Example: Citarum River – Indonesia

Prevention and Control of Pollutions

• Municipal and Industrial Treatment Plants: Installing and modernizing wastewater treatment facilities is necessary to properly filter industrial and sewage wastes before releasing them into bodies of water.

• Example: Municipal Wastewater Treatment – Singapore, which helps to meet 40% of Singapore’s water demand.

• Best Management Practices: Encourage best management practices in agriculture to reduce nutrient runoff, soil erosion, and pesticide contamination.

• Example: Milwaukee River Pay-For-Performance Project, which reduced phosphorus losses by as much as 40 percent from farms in the West Branch of the Milwaukee River Watershed.

• Recycling and Waste Minimization: Support industries to implement strategies that place a high priority on recycling, reducing waste, and safely disposing of hazardous materials.

• Water Quality Monitoring: To monitor changes in water quality, pinpoint the sources of pollution, and evaluate the efficacy of pollution control strategies, establish comprehensive monitoring programs.

• Example: AquaWatch Australia Mission, will provide close to real time water quality monitoring and forecasts aimed at improving seafood production and aquaculture management in Australia.

• Adaptive Management: Evaluate the efficiency of pollution control methods on a regular basis and modify strategies in response to new scientific discoveries and growing issues.

Government initiatives and policy measures

• National River Conservation Programme (NRCP): It aims to protect rivers from pollution and improve water quality.

• National Lake Conservation Programme (NLCP): To preserve and manage polluted and deteriorated lakes in urban and semi-urban regions.

• The Water (Prevention and Control of Pollution) Act, 1974: It was introduced to provide for the prevention and control of water pollution and the maintaining or restoring of wholesomeness of water.

• The Environment (Protection) Act, 1986: It gives the Central government the authority to set regulations for sewage and effluent discharge, look into and make sure compliance, and carry out research.

International initiatives

• International Initiative on Water Quality (IIWQ): To promote international collaboration, knowledge generation and dissemination, science-based decision-making, and innovative solutions, policy approaches and best practices to address water quality issues in a holistic manner.

• South Asia Water Initiative (SAWI): To increase regional cooperation in managing major Himalayan River systems and building climate resilience.

• Water Action Decade 2018-2028: It focuses on the sustainable development and integrated management of water resources for the achievement of social, economic and environmental objectives.

Case study

• Wastewater Management in Bengaluru and Nelamangala: Strategic in-stream treatment systems (STRAINS) interventions are intended to offer low-cost, low-tech, decentralised supplementary functions to top-down wastewater management practices, such as STPs.

Tags:
Environment

Keywords:
Pollution Water pollution Climate change Oil spill

Syllabus:
General Studies Paper 3

Topics:
Environment and Climate Change