Drinking Water Standards and Their Implementation—A Critical Assessment

Diminishing clean water resources and their pollution (due to human activities and climatic change) are of great concern on a global basis. Under such conditions, the adequacy of drinking water (DW) standards and their meticulous implementation are issues of utmost importance in safeguarding human health. Unfortunately, the significant number of disease outbreaks (and of other suspected/potential health effects) related to DW, even in developed countries, attests to the fact that these issues require vigilance and continuous re-appraisal, particularly considering the assorted emerging contaminants and the ever-improving technological tools to cope with them. Therefore, the present comprehensive assessment addresses the main issues and concerns regarding DW standards and implementation thereof. Emphasis is placed on identifying the inherent deficiencies of standards (due to neglect of potential toxic contaminants and to debatable specifications/limit values) and regulations for their implementation and the monitoring of DW quality (due to weaknesses of available analytical/measurement techniques and inadequacies of tools and protocols). Rather serious deficiencies on these aspects are evident regarding the main categories of contaminants, i.e., synthetic chemicals and biological species. In regard to addressing these issues, progress made in recent years at the scientific/technical level and the main challenges are outlined toward the goal of an improvement in standards and their implementation.