Deriving Surface Water Quality Closure Criteria - an Australian Uranium Mine Case Study

摘要

The Ranger Mine has been used as a case study to illustrate how field biological indicators of ecosystem status and results from ecotoxicological studies can be combined with a water quality record from downstream of a minesite to derive water quality guideline values that are not as conservative as would be produced by the default approach of conformance with an upstream, reference water body or historical reference condition. It has been argued that the trigger value framework developed for performance monitoring of water quality in Magela Creek during the operational life of the mine can be applied, with some modification, to post closure performance assessment. This approach would accommodate an ongoing finite level of input of solutes from the site whilst maintaining a sufficiently conservative level of protection for the downstream aquatic environment. Biological and water quality data have also been used to develop a technically defensible framework for deriving post closure water quality guidelines for an on site natural waterbody that has historically received low levels of inputs from the minesite.