EIS 418 rsi;1] Upper Brogo Mine Development: environmental impact statement i OD qu Th3/O7II UPPER BROGO MINE 0 DEVELOPMENT ENVIRONMENTAL IMPACT STATEMENT N.S.W. DEPARTMENT OF filgrFRAL JCES C.M. STEELE & ASSOCIATES fl UPPER BROGO MINE DEVELOPMENT . ENVIRONMENTAL IMPACT STATEMENT . C1M1 STEELE & ASSOCIATES 418 S S S UPPER BROGO MINING LEASE APPLICATION 39 S ENVIRONMENTAL IMPACT STATEMENT . FOR TWIN HILLS MINING N. 'Al,DEPARTMENT OF KRV UL 3CS ri - IJ) kJO S 0 Li • SECTION PAGE BACKGROUND INFORMATION 1/1 Location of Works 1/1 Nature and Extent of Works 1/1 Figure 1 : Map of Brogo District 1/1A • Figure 2 : Map of Brogo Catchment and Mining Lease 1/1B Tenure and Zonings 1/2 Existing Land Use 1/3 Figure 3 : Aerial Photograph of Mining Lease After Rain 1/3A Figure 4 : Map of Mining Lease MLA 39 1/3B 2 PROPOSED DEVELOPMENT 2/1 Construction Works 2/1 Proposed Mining Method 2/2 Figure 1 : Process Schematic 2/2A Extraction Process 2/3 • Staging and Progression 2/4 Table 1 1st Year Development Program 2/4 Exposed Areas 2/5 Hours of Operation 2/5 Proposed Workforce Numbers 2/5 Proposed Use of Disturbed Areas After Mining 2/5 • Access to Site and Roadworks 2/6 Proposed Transportation Arrangements 2/7 Table 2 : Vehicles to be Used 2/7 Table 3 : Number of Trips 2/7 Services 2/8 • 3 OBJECTIVES OF PROPOSED DEVELOPMENT 3/1 4 EXISTING ENVIRONMENT 4/1 Geology and Soils 4/1 Table 1 : Size of the Separates of the Soil 4/3 . Ore Analysis 4/4 Table 2 Chemical Analysis of Elements 4/4 Analytical Data 4/4A Fauna 4/5 Faunal Investigations in the Area 4/5 Small Ground Mammals 4/6 . Large Ground Mammals 4/6 Arboreal Mammals 4/7 Ambhibia and Reptiles 4/8 Birds 4/9 Rare and Endangered Species 4/9 Faunal Summation 4/10 Table 3 : Mammals 4/10 Reptiles 4/11 Amphibians 4/12 Birds 4/12 Flora 4/13 Riverine Type 4/14 Mid Slope Type 4/15 Ridge Type 4/17 Floral Summation 4/17 Table 4 Floral Species Referred to in Text 4/18 Rainfall and Run-off 4/19 • Table 5 : Rainfall Intensity 1 hr to 12 hrs 4/19 V CONTENTS Cont'd • SECTION PAGE 4 Figure 1 : 12 hr & 72 hr Rainfall Intensities - Upper Brogo 4/19A Figure 2 : Once in 10 Years Rainfall Intensities - Upper Brogo 4/19B • Table 6 Rainfall Intensity 6 mins to 60 mins 4/20 Brogo River 4/20 Climatic Conditions 4/21 Figure 5 Natural Sedimentation in First Creek - Mining Site 4/21A Figure 6 : Natural Sedimentation in Second • Creek - Mining Site 4/21B Table 7 : Monthly Rainfall Averages for Upper Brogo 1962-1973 4/22 Table 8 : Upper Brogo Rainfall 1977-1981 4/22 Table 9 : Average Over 25 Year Period - Bega Temperatures 4/23 • Table 10 Expected Wind Gusts in the Upper Brogo Area 4/25 Archaeological Items and Sacred Sites 4/25 Physical Setting 4/25 Figure 3 Sketch of Chopper Tool - Mining Site 4/25A Figure 4 Aboriginal Statement 4/25A • Vegetation 4/26 Archaeological Sites 4/26 Archaeological Evidence 4/28 Conclusions and Recommendations 4/29 References 4/30 • 5 ENVIRONMENTAL INTERACTIONS AND IMPACTS 5/1 The Earth 5/1 River System and Aquifer 5/1 Environmental Noise 5/2 Figure 1 Acoustic Spectrogram - Caterpillar 933G Mining Site Background Line - Still Day 5/2A • Figure 2 Acoustic Spectrogram - Honda G200 @ 1 m 5/2B Acoustic Spectrogram - Honda G200 @ 170 m 5/2B Figure 3 : Excess Sound Attenuation Through 5 m Wattle Regrowth 5/2C Table 1 Fresnel Numbers and Excess Attenuation Due to Diffraction by the Mountains 5/3 Instrumentation 5/3 Table 2 : Combined Noise Levels 5/3 Fauna 5/4 Flora 5/4 5/5 AirArchaeological Pollution Remains 5/5 Social Interactions 5/5 Figure 4 Wattle Regrowth Showing Frass due to Witchetty Grub Infestation 5/5A Visual Aspects 5/6 6 JUSTIFICATION OF THE DEVELOPMENT 6/1 Environmental Considerations 6/1 Economic Justification 6/1 Table 1 Capital Expenditure 6/1 Table 2 : Operating Costs and Returns 6/2 Social Justification 6/2 CONTENTS Cont'd S SECTION PAGE 7 ENVIRONMENTAL PROTECTION MEASURES 7/1 Soil Erosion 7/1 Figure 1 : Standard Diversion Channel 7/1A Water Pollution 7/2 S Figure 2 Particle Sizes of One Body 7/2A Air Pollution 7/3 Plantings of Trees and Grasses 7/3 [II ENERGY REQUIREMENTS 8/1 C 9 CONSEQUENCES OF NOT MINING 9/1 10 ACKNOWLEDGEMENTS 10/1 [] S 0 V ENVIRONMENTAL IMPACT STATEMENT This statement has been prepared on behalf of Twin Hills Mining, being the applicant making the development application referred to below. The statement accompanies the development application made in respect of the development described as follows:- Open-cut mining, processing of heavy metal deposits and restoration of the ground and indigenous flora. The development application relates to land described as follows: - Mining Lease Application 39 lodged at the Cooma Mining District Office on November 19, 1979. The said land being in the parish of Puen Buen in the county of Auckland, Crown land portion numbers 81, 82, 83, 84, 86, 94, 124, 126 and 147. The contents of this statement, as required by clause 34 of the Environmental Planning and Assessment Regulation, 1980, are set forth in the accompanying pages. Name, qualifications and address of person who prepared the Environmental Impact Statement:- Campbell N. Steele, J.P., F.I.E.Aust., Mem.A.S.M.E., M.A.A.S., M.A.S.A., Chartered Engineer, Australia. 74, Windang Road, Primbee, New South Wales. Certificate: - I, Campbell Maxwell Steele, of Primbee, hereby certify that I have prepared the contents of this statement in accordance with clauses 34 and 35 of the Environmental Planning and Assessment Regulation, 1980. [1 p4-J4-- ,½ g 1/1 1. BACKGROUND INFORMATION The subject of this environmental impact statement is the anticipated environmental impact of certain metalliferous exploration, mining, and treatment activities proposed by Twin Hills Mining. This proposed mining venture is also the subject of the 120 ha Mining Lease Application No. 39 lodged at the Cooma Mining District office on November 19, 1979. Location of Works The 120 ha lease site is on the banks of the flood and water storage easement of Brogo dam. Figure 1-1 shows Upper Brogo and Brogo dam in relation to nearby towns, highways, mountain and river systems. Figure 2 is a 1:10000 map showing the subject mining lease, nearby Upper Brogo and Brogo dam, located at approximately 1490 451 E, 360 301 S. There is no human habitation in the vicinity of the mining lease, the nearest neighbours being at "Hillfieldt' off the road to Quaama and at "Hum" further up the Brogo River valley. These neighbours are about 2km from the lease. • Nature and Extent of Works The proposal is for small scale exploration, open-cut mining and gravitational separation. This application is for mining and separation at the rate of 250 tonnes per day. This involves a capital investment of about $30,000 and is considered the smallest economical li NAROOMA [1 11 FIGURE 1-1 MAP OF BROGO DISTRICT NEKjHQU 1MA 14km 1/2 extraction rate for the deposit. However, should circumstances . change, Twin Hills Mining may wish to change this extraction rate. The estimated total reserves are 2,000,000 tonnes. Separation would be effected with a recirculating water system and make-up water from specially constructed dams and bores on the lease site. The recirculation rate would be about 90,000 litres per hour, make-up requirements are estimated at about 10,000 litres per day. Figure 1-2 shows three areas within the mining lease marked Site 1, Site 11 and Site 111. of these, Site 1 is to be set aside for offices, amenities and car park. Site 11 is proposed for the separation plant, settling ponds, and also for the initial open-cut mining. Site 111 is a future mining area. Tenure and Zonings S The whole of the land forming the proposed mining lease is Crown land held by the Water Resources Commission of N.S.W., who also own the land on all sides of the lease. Subject to satisfactory erosion control measures and replanting of natural and indigenous forest, the Water Resources . Commission offers no objection to the proposal. The land is located in the parish of Puen Buen, county of Auckland and lies in the Bega Valley Shire. The current land zoning is rural, 1(a). It comprises Crown land portion numbers 81, 82, 83, 84, 86, 94, 124, 126 and 147. This proposal is a designated development in the terms of the Environmental Planning and Assessment Regulation. 1/3 Existinq Land Use The mining lease site forms part of the catchment for Brogo dam. It was formerly part of a farm. This farm was abandoned some 20 years ago and the land is now subject to an unwanted regrowth of wattle trees. The photograph of figure 1-3 shows the site. The existing road is shown on the left hand side of the photograph. It leads to a clearing shown as Site 1 in figure 1-2. The partially cleared area further to the right is Site 111. Site 11 lies between the other two. Most of the proposed mining site has a gradient of between 1 in 20 and 1 in 10. The maximum gradient of land to be mined envisaged at this date is about 1 in 3. Figure 1-4 gives 10 m contours of the working sites.