EIS 110 Eraring Open Cut Coal Project
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EIS 110 Eraring open cut coal project: environmental impact statement. NSW DEPT PRIMARY I AAO57C THE ELECTRICITY COMMISSION OF NEW SOUTH WALES ERARING OPEN CUT COAL PROJECT ENVIRONMENTAL IMPACT STATEMENT THE ELECTRICITY COMMISSION OF NEW SOUTH WALES ERARING OPEN CUT COAL PROJECT ENVIRONMENTAL IMPACT STATEMENT MAY 1980 i I SUMMARY Eraring Open Cut Coal Mine is proposed as a source of coal for Eraring I Power Station. The Commission has planned the open cut to utilise a major resource and provide a stable and reliable coal supply to the power I station. I Location I The mine site is located 9 km south-west of Toronto, 3 km north of the village of Dora Creek, and 1 km north-east of the township of Cooranbong. There are approximately 50 million tonnes of coal within the site I boundaries and it is planned that the resource be worked at a rate of up to 2.5 million tonnes per year over a period of approximately 20 years. I Initial production is planned for 1983. Operations Control I The mine is to be operated by a contractor to the Electricity Commission. A Commission representative will be stationed at the mine site to oversee the mining operation, environmental conservation and reclamation. I Mining Plan Mining will commence with a box cut in the south eastern corner of the site I and progress from south to north. Mining practice will include removing high relief overburden with trucks and shovels, then stripping down to the I coal seams with draglines. The mine will employ approximately 270 persons. I A coal preparation plant which will have provision for a small washing I plant will be located south of the boxcut position. Coal from the prepa- ration plant and final products bin will be delivered to the power station I by conveyor under the Great Northern Rail Line. 1 Offices, workshops, bathhouse and store will be established on the western side of the mine. I Environmental Control Important aspects of the project which will be undertaken to minimise the environmental impact of the mining operation: A buffer zone 1 km wide around the mine boundary to be purchased partly from private landholders. Diversion of streams, through dems, to west of the mine site. Re-location of the Cooranbong/Freeman's Waterholes Road. Restriction of the area of exposed surface around the mining opera- tion to approximately 180 ha. Progressive reclamation with mine advance. Progressive drainage of run-off away from possible areas of con- tamination. Controlled burning of vegetation. Monitoring of site discharge. Commission control of site operations. The comprehensive measures proposed to assist environmental control of the project will be translated into specific limits to be imposed on the con- tractor by the Commission. The following limits are nominated in the impact statement: A reduction in flood levels at Dora Creek of up to 70 mm. Maintenance of the quality of water discharged from the site to ensure downstream waters are not contaminated. Maintenance of an average dust concentration at the buffer zone boundary of 25 ug/m3. iv I I A restriction of noise emissions from earthmoving plant to +5 dB(A) 1 of background values at the buffer zone boundary. I Restriction of the view of the mine from areas adjacent to the I buffer zone to an area specifically provided for that purpose. I The environmental issues of major concern in open cut coal mines have been accounted for at Eraring by providing a substantial buffer zone, limiting I the area of disturbed surface, maintaining reclamation work adjacent to the mining operation, planning and monitoring mining operations to control the I environmental impact and by establishing supervision by Commission officers on the project site. I As the Commission has not yet called tenders for the operation of the mine I details such as design of surface buildings, coal preparation plant, mining equipment and specific operating techniques cannot be nominated in detail. I I I I I I I I I I I AJ CONTENTS PAGE NO. STATEMENT OF OBJECTIVES OF THE PROPOSAL STATEMENT OF ALTERNATIVE PLANS CONSIDERED 3 Alternative Underground Mines in the Vicinity of Eraring Rail Transport of Coal Conclusion DESCRIPTION OF THE PROPOSAL 9 The Resource Mine Plan Mine Development Employment Surface Water and Groundwater Control Air Quality Control Noise Land Management STATEMENT OF CHARACTERISTICS AND CONDITIONS OF THE EXISTING ENVIRONMENT 25 The Community Land and Land Use Soil and Geology Climate Aboriginal Relics Fauna Flora Stream Flow and Flooding Water Quality Air Quality Acoustic Environment Existing Mine Workings INTERACTIONS BETWEEN THE PROJECT AND THE ENVIRONMENT 37 The Community Land and Land Use Aboriginal Relics Flora Fauna Water Discharges Flood Control Air Discharges Disposal of Vegetation Noise and Vibration Transport Visual Impact ASSESSMENT OF ENVIRONMENTAL IMPACT 45 vii PAGE NO. REFERENCES 7 APPENDIX 1 - INDICATIVE QUALITY OF ERARING COAL 1+9 APPENDIX 2 - SOIL TEST RESULTS 51 I APPENDIX 3 - ANALYSIS AND TESTING REPORT - BOREHOLE SAMPLES FROM THE PROPOSED ERARING OPEN CUT SITE 53 APPENDIX 'I - BORE WATER ANALYSIS 57 APPENDIX 5 - STREAM WATER QUALITY DATA - ERARING OPEN CUT MINE SITE 59 viii I I LIST OF ILLUSTRATIONS Figure I No. Description 1 Site Location I 2 Mine Site and Environs 3 Locations of Alternative Underground Mine Development I Typical Site Geology 5 Box Cut, Coal Preparation Plant, Support Facilities and Stream I Diversion 6 Mining Operations - Typical Cross-section I 7 Mining Operations - Plan I 8 Artist's Impression of Typical Mining Operations 9 Catchment Area 1 10 Stream Diversion and Water Storage 11 Water Treatment Schematic I 12 Settling Pond Layout I 13 Predicted Noise Contours 14 (a) Surface Contours - Pre-mining (b) Surface Contours - Post-mining I 15 Reclamation at Open Cut Coal Mines 1 16 Regional Land Use 17 Soil and Slope Classification I 18 Wind Roses 19 Land Acquisition I 20 Eraring Open Cut Schedule to Production I 21 View from Heatons Lookout 21a it I 22 Coal Preparation Flow Sheet I 23 Coal Preparation Plant Layout I I lx LIST OF ILLUSTRATIONS (CONTD.) Add end urn Al Earthworks Detail A2 Services Area Conceptual A3 Coal Preparation Plant Conceptual I I I I I I I I I I I 1. STATEMENT OF OBJECTIVES OF THE PROPOSAL The Eraring Open Cut Coal Project is to be undertaken to supply coal to Eraring Power Station, Figure 1. The station, now under construction, will comprise four 660 MW generating units giving a total generating capacity of 26240 MW. The first unit is planned for full operational service in 1982 and the second unit will be brought into full operational service in 1983. Units 3 and 1 will become available in 19824 and 1985. When in full commercial operation, the power station will consume 6.0 to 6.5 million tonnes of coal per annum. It is proposed that the coal supplies for Eraring be obtained from the following sources: Millions of Tonnes of Coal per Annum Myuna Underground Colliery (under construction) 1.5 Cooranbong Underground Colliery (under construction) 1.5 Awaba Underground Colliery 0.6 Eraring Open Cut Coal Mine 2.5 I The steaming coal resources of the Great Northern and Fassifern Seams intended to be developed in the open cut mine lie to the west of, and adjacent to, the Eraring Power Station. The Great Northern Rail Line separates the mine from the power station site, Figure 2. The soils and rocks overlying the coal seam (overburden) and the materials lying between the seams (interburden) are of such nature and thickness that mining by underground methods would be unlikely to recover more than 25 percent of the total coal resource in the proposed open cut mining area. The open cut coal mine at Eraring will be capable of recovering in excess of 90% of the resource. The mine will extract 50 million tonnes of coal at a rate of up to 2.5 million tonnes of coal per annum, of a quality suitable for fuelling the Eraring Power Station, in an environmentally acceptable manner and with a minimum of long term disturbance to the existing environ- ment. SECTION 2 Statement of Afternafive Plans Considered 2. STATEMENT OF ALTERNATIVE PLANS CONSIDERED Eraring Power Station will require from 6.0 to 6.5 million tonnes of coal per annum from 1985. Underground collieries at Myuna and Cooranbong are now under construction and detailed consideration of mining operations indicates that production levels in excess of 1.5 million tonnes average annual production from these mines will be very difficult to achieve. The reserves of coal available to these mines are limited and, as much of the coal is under water or low lying land, first workings only can be safely permitted over much of the mining area. It would be impracticable to maintain a rate of mine develop- ment that could support sufficient working faces to produce annual quantities in excess of the currently planned figures for a protracted period. Having regard for the normal difficulties in underground coal mining, it is also considered unwise to commit too high a proportion of the supply of coal to a major power station to any one underground mine. The Awaba Mine has been operating for many years and its remaining reserves I of Great Northern Seam coal are limited to the extent that it would be impracticable to redevelop the mine to produce at a substantially higher I rate than the current level of 0.6 million tonnes per annum. I Allowing for the production of a total of 3.6 million tonnes per annum from underground mines the balance of from 2.4 to 2.9 million tonnes could be obtained from one of, or a combination of, three difference sources.