The Lubbock Infection Surveillance Study monitored bacterial infections in the vicinity of the Lubbock Land Treatment System expansion near Wilson, Texas to investigate the association, if any, between the occurrence of new bacterial infection in people and their exposure through slow rate (sprinkler) land application to wastewater or its aerosol which contained potentially pathogenic bacteria. Bacterial infections were monitored during the first four major periods of wastewater irrigation: February-April 1982, July-September 1982, February-April 1983 and July-August 1983. Fecal specimens were provided by about 120 donors in 1982 and 100 donors in 1983 during designated weeks just before, during and near the end of each irrigation period to detect new bacterial infections occurring in the interim. Clinical bacteriological analyses were designed to isolate overt and opportunistic pathogens.