The report presents the results of a study of the Santee, California recreational lakes, which were deliberately planned to utilize the community's reclaimed sewage effluent. By the summer of 1965, a special basin adjacent to one of the lakes was supplied with reclaimed water and used for swimming. A seven-agency cooperative study evaluated the content of waste water passed through conventional secondary treatment processes, the sand filtration, and the recreational lakes. No health hazards were demonstrated by the viral or other findings, and this fact had considerable impact in the promotion of public acceptance of the use of the recreational facilities.