Tomago Aluminium Company Annual Environment Report 2020 ANNUAL ENVIRONMENT REPORT 2020 PREPARED JAN/FEB 2021 Page 1 of 97 Contents EXECUTIVE SUMMARY ....................................................................................................................................................... 4 1. INTRODUCTION ............................................................................................................................................................ 6 2. SITE DESCRIPTION ....................................................................................................................................................... 7 3. COMPANY HISTORY – CONDITIONS OF DEVELOPMENT CONSENT .............................................................. 10 3.1 Current Approvals for TAC ................................................................................................................................... 10 3.2 Status of Development Consent Conditions .......................................................................................................... 11 3.3 Performance of the Development .......................................................................................................................... 16 4. ENVIRONMENT MANAGEMENT AND PERFORMANCE ..................................................................................... 17 4.1 Environment Management System ........................................................................................................................ 17 4.2 Air Quality ............................................................................................................................................................. 17 4.2.1 Source Emissions ................................................................................................................................................... 17 4.2.1.1 Fluoride Source Emissions ................................................................................................................................ 17 4.2.1.2 Sulfur Dioxide Source Emissions ...................................................................................................................... 20 4.2.1.3 Other Source Emissions .................................................................................................................................... 22 4.2.2 Ambient Air Monitoring ........................................................................................................................................ 24 4.2.2.1 Ambient Fluoride Monitoring ........................................................................................................................... 24 4.2.2.2 Ambient Sulfur Dioxide Monitoring ................................................................................................................. 33 4.3 Meteorological Monitoring .................................................................................................................................... 37 5. VEGETATION ............................................................................................................................................................... 38 5.1 Visual Assessment ................................................................................................................................................. 38 5.2 Overstorey Monitoring .......................................................................................................................................... 40 5.3 Forage .................................................................................................................................................................... 42 5.4 Cultivated Vegetation ............................................................................................................................................ 44 6. ECOSYSTEM MONITORING ...................................................................................................................................... 44 7. WATER .......................................................................................................................................................................... 45 7.1 Surface Water ........................................................................................................................................................ 45 7.2 Groundwater Monitoring ....................................................................................................................................... 48 7.2.1 Groundwater Monitoring General ......................................................................................................................... 48 7.2.2 Assessment of Groundwater Monitoring Data ....................................................................................................... 48 7.2.3 Piezometry and Groundwater Flow ....................................................................................................................... 61 7.3 Stormwater ............................................................................................................................................................. 63 7.4 Hunter River Monitoring ....................................................................................................................................... 69 7.5 Bio-Accumulation Program ................................................................................................................................... 70 8. ENERGY ........................................................................................................................................................................ 77 9. WASTE MANAGEMENT ............................................................................................................................................. 78 9.1 Aluminium Smelter Waste ..................................................................................................................................... 78 9.3 Wallaroo Waste Disposal Facility ......................................................................................................................... 80 10 NOISE ............................................................................................................................................................................ 86 11 INDEPENDENT AUDITS ............................................................................................................................................. 90 12 REFERENCES ............................................................................................................................................................... 91 APPENDIX 1 - SAMPLING SITE LOCATIONS .............................................................. 92 ANNUAL ENVIRONMENT REPORT 2020 PREPARED JAN/FEB 2021 Page 2 of 97 APPENDIX 2 - SAMPLING PROCEDURES .................................................................... 93 APPENDIX 3 - EPL 6163 TOMAGO ALUMINIUM SITE ............................................... 95 APPENDIX 4 – EPL 6048 WALLAROO WASTE SITE ................................................... 96 APPENDIX 5 - DEVELOPMENT CONSENT CONDITIONS ......................................... 97 ANNUAL ENVIRONMENT REPORT 2020 PREPARED JAN/FEB 2021 Page 3 of 97 EXECUTIVE SUMMARY This Annual Report details the environment management and monitoring program implemented in 2020 by Tomago Aluminium Company to meet the requirements of the Development Consent conditions (DA 391-80 & DA 4908-90). Tomago Aluminium produced 590,916 tonnes of saleable aluminium in 2020. Overall Environmental Management during 2020 was effective with compliance with conditions being achieved with the exception of some samples being unable to be taken due to the omgoing drought legacy and minor equipment breakdowns. Air Quality An annual average fluoride emission rate of 0.46 kilograms of fluoride per tonne of aluminium produced was achieved. Concentration and Load Based Limits based limits on fluoride, sulfur dioxide, particulates and nitrogen oxides were met. Ambient monitoring for fluoride demonstrated close alignment with EIS modelled concentrations apart from Site 181 (Tomago Farm) and all monitoring sites outside the designated buffer zone met the ANZECC air quality guidelines for fluoride. The sites have seen relatively consistent average ambient concentrations in relation to prior years for both fluoride and sulfur dioxide in 2020. There was one single day during 2020 when the 24 hour sulfur dioxide average exceeded the NEPM standard level at The Tomago Farm site. All the ambient sulfur dioxide monitoring stations are located within the designated buffer zone for the smelter. Vegetation Vegetation monitoring highlighted that the fluoride impact on vegetation is confined to areas close to the smelter perimeter. The area of impact has again decreased slightly from 2019, while the area showing marked or more severe injury has increased slightly. Fluoride concentrations in both overstorey and forage at the monitoring sites remain relatively stable. Water Monitoring of surface water, groundwater and stormwater on the smelter site and the surrounding environs was completed in 2020, with sampling of the Hunter River routinely for metals continued. Surface water Eleven of twelve sites were monitored monthly. Some slight elevation in fluoride levels is evident at two sites very close to the smelter, however the fluoride concentrations measured