An assessment of the suitability of a range of chemical and biological tracers to monitor the movement of septic tank effluents to groundwater

Abstract

The paper describes the main results of an investigation which examined the movement of septic tank effluent through soil/overburden to groundwater at three geologically and hydrogeologically differing sites using a range of chemical and biological tracers. The results of the study demonstrated that a single tracer type cannot be used to accurately monitor the movement of all effluent constituents through soils and groundwater. The results also indicated that the combined use of nitrate and/or bromide ions and endospores of Bacillus globigii would give an accurate indication of the movement of both the chemical and biological constituents of septic tank effluent.

Key index words:

• Septic tank effluent
• groundwater
• tracing