Sewage discharge, including untreated or partially treated wastewater, is a major contributor to water pollution in urban areas, leading to contamination with harmful bacteria, nutrients, and other pollutants.

Excessive fertilizer application in agriculture can result in nutrient runoff, leading to eutrophication and water pollution. Fertilizers contain high levels of nitrogen and phosphorus, which can cause algal blooms and disrupt aquatic ecosystems.

Eutrophication is the process by which excess nutrients, primarily nitrogen and phosphorus, stimulate excessive growth of algae and other aquatic plants, leading to oxygen depletion and disruption of aquatic ecosystems.

Manufacturing industries, particularly those involved in chemical production, metal processing, and textile manufacturing, often release toxic chemicals and heavy metals into water bodies, causing contamination and posing risks to aquatic life and human health.

Ship accidents, including collisions, groundings, and oil tanker spills, are the primary cause of oil spills in marine environments. These accidents can result in the release of large amounts of oil into the ocean, causing extensive damage to marine ecosystems.

Asbestos fibers, when inhaled, can cause severe respiratory problems, including lung cancer and mesothelioma. Asbestos was widely used in building materials and insulation before its hazards were fully understood, and its presence in water sources can pose health risks.

Water filtration involves passing water through a physical barrier to remove suspended particles, bacteria, and other contaminants. It is a crucial step in water treatment to ensure the removal of harmful substances and improve water quality.

Drip irrigation is a water conservation practice that involves delivering water directly to the roots of plants through a network of pipes and emitters. It minimizes water loss due to evaporation and runoff, making it an efficient irrigation method.

Water recycling involves treating wastewater to remove contaminants and impurities, making it suitable for reuse in various applications, such as irrigation, industrial processes, or groundwater recharge.

The Ramsar Convention, also known as the Convention on Wetlands, is an international agreement that aims to protect and restore wetlands and promote sustainable water management practices. It recognizes the importance of wetlands for biodiversity conservation, water storage, and flood control.

Climate change, particularly in the form of rising temperatures and altered precipitation patterns, is a major cause of water scarcity in arid and semi-arid regions. These regions are already characterized by limited water resources, and climate change exacerbates the situation, leading to droughts and water shortages.

Water conservation practices in households and businesses include measures such as fixing leaky faucets, installing low-flow appliances, and reducing water usage for non-essential purposes. These practices aim to minimize water consumption and promote efficient water use.

Water restoration involves implementing measures to improve the quality of degraded water bodies, such as removing pollutants, restoring natural habitats, and controlling invasive species. The goal is to restore the ecological integrity and functionality of these water bodies.

The United Nations Environment Programme (UNEP) is the leading international organization responsible for coordinating global efforts to address environmental issues, including water pollution and sustainable water management. UNEP works with governments, businesses, and civil society organizations to promote policies and practices that protect water resources and ensure equitable access to clean water.