GASTROINTESTINAL DISTURBANCES DUE TO AN ESTABLISHED BACTERIAL CONTAMINATION OF A WATER DISTRIBUTION SYSTEM
In Hörnefors, a village at the east coast of northern Sweden, a new ground water well almost free from detectable bacteria was connected to the old water distribution system, and chlorination was withdrawn. Within four months bacteriological controls indicated the presence of bacterial counts exceeding official limits in drinking water, and an epidemiological survey showed an unexpectedly high incidence of gastrointestinal disturbances. Several possible enteropathogenic bacteria were detected in tap water. It is suggested that a contamination of the distribution system from the former water catchment was allowed to multiply when chlorination was withdrawn. Chlorination was reinstituted and continued for six years whereafter chlorination could be subsided without bacteriological or infectious complications.