This article offers an overview of the draft groundwater disinfection rule, released for public comment by the USEPA on July 31, 1992. The rule is abbreviated GWDR. This article explains which systems are affected by the rule and major features of the rule. MCLGs will be set for microbials, and a treatment technique would be set in lieu of MCLs. Disinfection of source water will be required unless the wells meet "natural disinfection criteria" or the system qualifies for a variance. (A table summarizes natural disinfection criteria options.) In addition to the natural disinfection criteria, wells must also meet prequalifying conditions, such as meeting state-approved well construction codes. The well also cannot have been identified as the source of a waterborne disease outbreak or violation of the total coliform rule (or, if so, the cause must be remedied). Disinfection of source water, when required, must meet performance criteria; ultraviolet light disinfection would be allowed. Disinfection of the distribution would be required. Qualified operators would be required. Administrative issues are also covered: approved analytical methods, reporting requirements, compliance time frames, and allowances for variances and exemptions. Includes 7 references, tables.