An examination of the potential added value of water safety plans to the United States national drinking water legislation.

National and sub-national governments develop and enforce regulations to ensure the delivery of safe drinking water in the United States (US) and countries worldwide. However, periodic contamination events, waterborne endemic illness and outbreaks of waterborne disease still occur, illustrating that delivery of safe drinking water is not guaranteed. In this study, we examined the potential added value of a preventive risk management approach, specifically, water safety plans (WSPs), in the US in order to improve drinking water quality. We undertook a comparative analysis between US drinking water regulations and WSP steps to analyze the similarities and differences between them, and identify how WSPs might complement drinking water regulations in the US. Findings show that US drinking water regulations and WSP steps were aligned in the areas of describing the water supply system and defining monitoring and controls. However, gaps exist between US drinking water regulations and WSPs in the areas of team procedures and training, internal risk assessment and prioritization, and management procedures and plans. The study contributes to understanding both required and voluntary drinking water management practices in the US and how implementing water safety plans could benefit water systems to improve drinking water quality and human health.