Survey to Detect Legionella pneumophila in Potable Waters in North West England

Legionella PNEUMOPHILA is a causative agent of respiratory illness in humans. The organism is ubiquitous and commonly frequents aquatic environments. Incidents of legionellosis have been linked with potable water supplies. An attempt has been made to determine the degree of contamination, if any, by L. pneumophila in samples of potable water treated and distributed to domestic premises in the north west of England. Sampling was initiated in February 1986 and continued throughout the summer months of 1986 and 1987. The majority of sampling sites were chosen at random, but from areas suspected of having dirty water problems or low chlorine residuals. In a few cases samples were taken where there was a known problem, such as a consumer complaint or bacteriological failure. Results indicate that public potable water supplied in this area does not constitute a significant health risk in the transmission of the disease. Other environmnental factors appear more significant.