Pre-release biological toxicity testing of Djalkmara Billabong water: 2003-2004 wet season

Department of the Environment and Heritage, 2004

Internal Report 478
Van Dam R, Hogan A & Nou S
Supervising Scientist Division

About the report

The aim of the pre release toxicity testing program was to assess the toxicity of Djalkmara Billabong water to three local freshwater species and, based on the results, calculate a minimum ‘safe’ dilution level required for controlled release to Magela Creek. The pre-release toxicity testing program for the 2003-04 wet season was agreed to by SSD and ERA as specified in the Letter of Agreement provided in Appendix A. Pre-release toxicity testing took place on two separate occasions. The first round of tests was undertaken one week before Christmas (late December 2003) to ensure that Ranger environmental staff had appropriate toxicological information and advice over the holiday break in the event that extremely high rainfall necessitated the release of Djalkmara Billabong water during this period. The second round of tests took place in mid January 2004, after the billabong had received a large amount of rainfall and associated runoff from the designated areas on the mine site. Throughout this report the two testing rounds are referred to as the December and January testing rounds.