The paper presents the results of a study of the Santee, California, recreational lakes. These lakes were deliberately planned to utilize the community's reclaimed sewage effluent. The seven-agency cooperative study evaluated the fate of virus along with total and fecal coliform and fecal streptococci through the conventional secondary treatment process, the tertiary processes, and the recreational lakes. The correlating physical and chemical data were also presented along with a bio-logical study of the lakes and related land area. Discussions of eutrophication, vector control, epidemiology, and the social acceptance and ecology of the entire recreational park are developed. The study concludes that the treatment provided by intermittent sand filtration met the nutrient requirements of the emerging ecology and that no health hazards were demonstrated by the viral or other findings for the present recreational uses of boating and fishing. (Author)