tapwater

Tap water refers to water supplied to households and businesses through a public distribution system, typically drawn from surface water or groundwater. It is distinct from bottled water and from private wells in many regions. In most countries tap water is treated and disinfected before distribution to meet drinking water standards set by regulatory authorities.

Treatment commonly includes coagulation and flocculation to remove suspended particles, sedimentation, filtration, and disinfection using chlorine, chloramine, or alternative methods. Additional steps may address corrosion control, pH adjustment, and the removal of specific contaminants or taste and odor issues. Some systems also monitor and adjust the mineral content to influence stability and taste.

Water quality is regularly tested by public health authorities. Standards cover microbiological safety (for example, absence of pathogenic bacteria), inorganic constituents (such as lead, arsenic, nitrates), organic contaminants, disinfection byproducts, and radioactivity where applicable. If contaminants exceed permitted limits, advisories, warnings, or corrective actions are issued, and consumers may be advised to use home treatment or alternate supplies temporarily.

Common concerns include taste and odor, which can be influenced by minerals, chlorine residuals, or aging pipes. Lead exposure remains a priority in areas with older plumbing; mitigation strategies include corrosion control, replacement of lead service lines, and consumer guidance. Point-of-use filters can reduce certain contaminants but are not a substitute for system-level treatment.

Tap water is usually inexpensive and widely available, supporting public health and daily hygiene. Its delivery relies on extensive infrastructure, and some regions face shortages or drought. Fluoridation is employed in some locales as a public health measure, though it is occasionally debated.

Regulatory frameworks, such as national drinking water acts or regional directives, govern monitoring, reporting, and allowable contaminant levels, with emergency measures like boil-water advisories used during disruptions.