Abstract
Surface waters in 14 selected sites were examined for the presence of salmonella using modified Moore's swabs. The sites included an upland impounding reservoir, 3 rivers and 10 streams within Lancashire and Cheshire, selected because of their accessibility to farm livestock. Salmonellas were isolated from 22 out of the 57 swabs examined representing 10 sites. The probable source of pollution was shown to be sewage or farm effluent and an examination of sites over a wider area may be expected to produce similar results. The significance of these findings is discussed in relation to the epidemiology of salmonella infections and the possible disinfection of effluent discharges.