EPA is in the process of developing requirements for disinfection of groundwater-based drinking water systems (Groundwater Disinfection Rule, GWDR). Because the approach now being taken for this is somewhat different from that taken for other drinking water regulations, this paper will discuss the context, issues and status of this rule as of June, 1995. The goals for the GWDR are that it make a positive impact on public health by ensuring that those drinking groundwater are safe from waterborne microbial disease, that it be feasible and that it can be successfully implemented. Because of the health hazards, widespread occurrences, well-documented continuous contamination of wells and distribution systems, and the existence of reliable and affordable treatment technology there are substantial reasons for EPA to move ahead with the development of a GWDR.