SUMMARY:Differences have been noted in the numbers of excretal organisms isolated from water supplies coming from gathering grounds with soils of different types. Those from acid moorlands normally contained smaller numbers ofBact. colitype I than those from limestone areas, although the numbers of animals present in the areas were approximately the same.The technique is described for a study of the effect of soils from these areas on the survival of excretal organisms. Incubation of samples of the soils after inoculation withBact. colitype I and withStrep. faecalishas shown that both organisms will persist in the limestone soils for several weeks but die out in a few days in acid peat soils. When chalk is added to the acid soils both organisms were able to persist for several months. It is suggested that survival is largely governed by pH.
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