Abstract
A total of 882 samples of settled sewage, sewage sludges and final effluents from eight sewage treatment plants were examined for the presence of salmonellas. Of these samples 68% were positive, isolations being made most frequently from settled sewage (85%), raw sludge (87%) and anaerobically digested sludge (96%). Fewer isolations were made from final effluent (24%) and processed sludges (58%). Samples usually contained less than 200 salmonellas/100 ml and arguments are presented that such concentrations should not lead to disease in animals if suitable grazing restrictions are followed.