How is contamination defined in water quality terms?

Contamination in water quality terms refers to the impairment of water quality by harmful substances. This definition involves the introduction of pollutants or harmful elements that degrade the water's purity, making it unsafe for use or detrimental to aquatic ecosystems. Understanding contamination is crucial because it highlights the potential risks associated with water sources and the importance of maintaining clean and safe water supplies.

Improvement of water quality is fundamentally different; it suggests enhancing the quality rather than degrading it. Approved alterations relate to legal or permissible changes to water attributes, indicating that these changes are managed and monitored instead of being harmful. Natural variations in water quality acknowledge the inherent changes that occur in water systems due to environmental factors, which are not necessarily harmful but part of natural processes. In contrast, contamination specifically points to the introduction of unwanted and dangerous substances into water.