Evaluation and use of a biotracer to study ground water contamination by leaching bed systems

摘要

There is an increasing concern about dangerous levels of bacterial contamination of rural ground water resources in Ontario and throughout the world. Recent studies in rural parts of Canada have identified leaching bed systems as one of the major sources of this contamination. Field studies were undertaken to evaluate bacterial contamination from three different types of leaching bed designs, using nalidixic acid-resistant Escherichia coli (E. coli NAR) as a biotracer. This biotracer was used rather than passive ground water sampling to clearly identify the source of the contamination and also to allow the determination of travel times and distances more clearly. While this biotracer has been used for other studies its use in actual working septic systems has not yet been reported.