What Do We Mean by Water Quality-
Grasping Water Quality Concepts
Defining water quality is a complex task, akin to the fluid and ever-shifting characteristics of nature itself. Water, much like the changing seasons, undergoes its own metamorphoses. Usually, the topic of water quality is explored within a technical framework, relating to its ‘scientific’ attributes. However, the term can also be interpreted in a different light. In scientific and legal domains, the prevailing definition states: Water quality pertains to a water body’s ability to support all relevant beneficial uses, including its use by humans and wildlife for drinking and as a habitat for fish. When water meets these beneficial uses, it is considered to have good or unimpaired quality; conversely, failure to meet these uses deems it as poor or impaired.
A key point to consider is that different beneficial uses require different standards. While many equate high-quality water with purity and cleanliness, especially for drinking, this is only one aspect of the equation. Aquatic life depends on water for oxygen and nourishment, necessitating water that is rich in oxygen and nutrients. Thus, superior water quality is marked by the absence of detrimental substances (pollutants) and the presence of vital elements (oxygen, nutrients).
Evaluation of water quality often hinges on its chemical, physical, and biological properties. The state of water in rivers and lakes inherently varies with the seasons and location, even without pollutants. Contrary to popular belief, there is no universal benchmark for good water quality. For instance, water that is safe to drink might be suitable for irrigation, yet irrigation water may not meet the standards for drinking.
Water quality guidelines provide essential scientific knowledge about quality parameters and toxicological threshold values pertinent to specific water uses. With a foundational understanding of water quality, it is crucial to establish quantifiable parameters to assess the quality of water bodies such as rivers, streams, or lakes. These parameters include physical, chemical, and biological characteristics. Physical measurements involve factors like water temperature, depth, flow velocity, flow rate, and turbidity, which are instrumental in understanding the movement and mixing of pollutants and the habitat requirements of aquatic life.
Chemical measurements encompass a wide array of substances and properties, focusing on the concentration of chemicals within the water. Although even the purest water contains numerous chemicals, water quality studies zero in on those most relevant to the particular context, such as those found in agricultural or industrial zones.
Water quality is a nuanced concept that can be examined through various methodologies. This discourse does not cover all facets of water quality assessment but underscores the dynamic nature of water, necessitating continuous monitoring and research for effective treatment and safety. The next time you take a drink, take a moment to consider the original state and quality of the water before it became safe for you to consume.