This standard covers the minimum requirements for vertical water supply wells, including geologic/hydrologic conditions and water quality and well construction. This standard can be referenced in specifications for constructing water wells and can be used as a guide for vertical water supply wells. The stipulations of this standard apply when this document has been referenced and then only to water wells used in water supply service applications. Application of this standard is not limited by well depth. Topics covered include: investigation of geologic/hydrologic conditions and groundwater quality; material requirements; well casing; well screens; gravel pack; well construction; well development; well disinfection; decommissioning of test holes, partially completed wells, and abandoned wells; verification; performance testing; water quality testing; and, delivery. Major revisions to this edition include the following: The water-cement ratio of neat cement grout when using bentonite additive is clarified. Provisions requiring current laboratory analysis and quality assurance of gravel filter materials delivered to jobsite are provided. Appendixes cover: gravel-pack installation methods; grouting and sealing - methods of placement; plumbness and alignment - procedure and testing; well development; water sampling - suggested methods; factors influencing the duration of pumping test; decommissioning of test holes, partially completed wells, and abandoned completed wells; geophysical borehole logs; types of wells; and, collapse strength of well casing.