Tritium in waste as a tracer of landfill leachate in surface and ground water in South Africa

Tritium concentrations higher than expected environmental levels were first discovered in South Africa in association with landfill sites in 1995. Since then, a survey has identified numerous landfill sites of various types which produce leachate containing elevated levels of tritium, in one case 105 TU, approaching the limit for drinking water. Tritium, a low energy (18 keV max) β emitter, half-life 12.43 years, is a conservative tracer of water in the oxidised state. It exchanges readily between different chemical compounds, such as tritium-containing material and moisture moving through a landfill. In southern Africa at present the range of tritium values in rain is close to the assumed natural level (about 5 TU), about one order of magnitude lower than contemporary values in e.g. western Europe with much more extensive industrial use and release of tritium. This renders very sensitive the tracing of leachate containing waste tritium in the southern African environment