Water Quality is the characterization of the physical, chemical, and biological properties of water relative to its suitability for a specific use. In engineering practice, water quality is not an abstract concept, it is defined against measurable parameters and regulatory or performance criteria associated with intended applications such as potable supply, industrial process water, irrigation, aquatic habitat support, or wastewater discharge. The assessment of water quality therefore requires quantitative analysis and comparison against established standards or design requirements.
From a physical standpoint, water quality parameters include temperature, turbidity, color, taste, odor, and total suspended solids. These characteristics influence hydraulic performance, treatment efficiency, scaling and fouling potential, and user acceptability.
From a chemical standpoint, water quality is evaluated using parameters such as \(pH\), alkalinity, hardness, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, total dissolved solids, nutrients, heavy metals, and organic contaminants. These constituents affect corrosion potential, scaling tendencies, toxicity, treatability, and compliance with environmental or drinking water standards.
From a biological standpoint, water quality includes the presence or absence of pathogenic microorganisms such as bacteria, viruses, and protozoa. Microbiological quality is critical for drinking water safety and for protection of public health in recreational and wastewater reuse applications.
Water quality is commonly evaluated using standardized analytical methods developed by recognized bodies. Measurements are compared against regulatory standards, design specifications, or environmental criteria established by governmental or professional authorities. Water quality is therefore a multidimensional, measurable condition of water that determines its fitness for a defined purpose. It is not an intrinsic absolute property; rather, it is a function of intended use and compliance with established quantitative criteria.
