Waste waters from mine sites may be screened for all constituents of
significance as a first step in establishing water quality criteria for
protection of aquatic ecosystems. Inductively-coupled plasma mass
spectrometry (ICP-MS) offers the capability to screen water samples and
digest solutions for virtually all elements in the periodic table. This
technique is therefore able to identify elements whose concentrations are
elevated in waste waters and may be rarely present in background surface
or ground waters. Such elements may be present in waters at only a few
g/L. ICP-MS has sufficient sensitivity to detect sub-g/L or even ng/L
levels of many elements. Waste waters from most mining activities in the Northern Territory
have been examined by ICP-MS. The concentration data provide the
basis of a contaminant data base. The data can show specific tracers in
the ore or mineral itself, subsequently found in waste water. An example
is the presence of rhenium in uranium ore. Such trace elements may be
present in soluble or insoluble chemical forms and are more useful as
indicators when soluble and exemplifying conservative chemical
behaviour. The approach described, based on ICP-MS screening of mine site
waste waters, together with general physico-chemical variables, provides
the most comprehensive means yet available of selecting variables for
monitoring programs and ensures that key elements and/or their chemical
species are not excluded from monitoring programs.