EIS 110 Eraring Open Cut Coal Project

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 preparation 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 operation to approximately 180 ha.

Progressive reclamation with mine advance.

Progressive drainage of run-off away from possible areas of contamination.

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 contractor 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 environment. 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 development 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.

Development of additional underground mines in the vicinity of Eraring.

Production of coal remote from the Eraring district by either open cut I or underground methods and transporting by rail or other means to the power station. I Development of the Eraring Open Cut proposed in this report. I

91 Alternative Underground Mines in the Vicinity of Eraring

The reserves of Great Northern and Fassifern steaming coal in the immediate vicinity of the power station are already allocated to the Awaba, Myuna and Cooranbong underground mines and the proposed Eraring open cut mine. The reserves of coal allocated to the open cut would not form a suitable basis for a new underground mine, as insufficient coal extractable by underground methods is available for the operating life of a new mine. Of the 50 million tonnes of coal available on site it is expected that not more than 12 million tonnes could be economically extracted by conventional underground mining.

The limitations on underground mining are:

The two major seams are separated by a relatively thin ply of claystone and it would not be practicable to extract the lower Fassifern Seam by bord and pillar mining once the overlying Great Northern Seam had been worked, without resorting to mining practices involving high capital cost and very low productivity.

In some areas the coal is too shallow for safe extraction by underground methods.

Unless great care in selection of the area for underground mining is exercised, the generally shallow depth of the workings could result in uncontrolled severe subsidence eharacterised by sink holes and stepped vertical displacement at the surface, even to the extent of unsafe conditions at the surface.

Alternative methods of underground mining such as longwall would be unacceptable at these depths due to surface effects and the possibility of flooding the mine from surface sources. There is also doubt that mechanical longwall would be an efficient means of working the coal having regard for the roof condition in some areas.

Additional reserves of the Great Northern and Fassifern coal seams exist I south-east of the Cooranbong Colliery under Lake Macquarie and under the Morisset Peninsula in quantities known to be adequate to support one or I more new large underground mines.

The head works for such mines could be established on the Morisset Peninsula and/or in one of several locations south of Dora Creek, e.g., A and B locations shown in Figure 3.

While further detailed investigations would be required to establish the I best location for alternative underground mines to the south of Eraring, there is little doubt that suitable locations could be found or that suffi- I cient coal could be produced from such mines as alternatives to the open cut proposal. i Underground mines in the conditions existing in the region cannot expect, in any circumstances, to approach the high productivity of an open cut mine, and inevitably the cost of production of the underground coal would be significantly higher than the open cut alternative. Of equal if not I greater importance would be the costs and environmental factors involved in transporting the coal from the possible mine sites to the power station I site.

The Commission has previously stated that it does not propose to use public roads for coal transport to Eraring. The remaining practical alternatives for transport are:

1. The construction of a private road from the new mines to Cooranbong I Colliery. This would require a new bridge over Dora Creek and would ' make such haulage dependent upon the use of diesel fuel, a resource which is expected to become relatively scarce and expensive.

The construction of a conveyor from the mine sites to the power station (minimum length 7 km).

The construction of rail sidings from the main northern line to the mine sites, and rail loading facilities at the mines.

14• I Underground transport of the coal. 1 5 It is considered that alternatives 1 and 2 are technically feasible, but that both involve substantial problems in the selection of a suitable route that would be acceptable on technical and environmental grounds.

Rail transport is also technically feasible but the cost of building, maintaining and operating the train loading and unloading facilities would result in a very high cost of transport over this relatively short distance. Difficulties may also be experienced in scheduling trains through crossovers on and off the main line over such a distance.

Underground transport of coal through mine workings from the Morisset Peninsula, would clearly have substantial environmental advantages. While the upkeep of the underground system may be costly, at the present time it is a preferred system. However, such a scheme can only be considered when the mine workings have been developed to a sufficiently advanced stage to provide the required connections. This could not be achieved in time to meet the requirements of Nos. 3 and 14 Units at Eraring and an alternative temporary supply would be necessary for the intervening years.

A further possibility is to develop the deeper coal resources of the Young Wallsend and West Borehole seams that are known to underlie parts of the Awaba State Mine holding at a depth of about 250 m. Development to the West Borehole, mined at Newstan Colliery, may be possible but would not be economic or sufficiently productive to contribute significantly to the power station coal supply.

Rail Transport of Coal

Provision has been made to establish a rail unloading loop at Eraring Power Station to receive coal from other centres if the power station cannot be fully supplied from local sources.

The most likely source of rail delivered coal would be the Hunter Valley mines. There are a number of reasons for this alternative not being favoured as a major source of the coal supply to Eraring.

Commission mines working leases in the Hunter Valley are committed to suppying Liddell and the future Bayswater power stations. Future expansion of industry in the area is likely to require commitment of all steaming coal available from these mines for power generation. The export market for steaming coal is expanding rapidly and the supply from private coal producers cannot be assured except at the equivalent of export price on a cost per heat unit basis which is expected to increase at a substantially higher rate than the cost of production.

Rail delivered coal would have a cost disadvantage over local sources.

rr.r.e.1 lie, ,V,

Two new underground mines would be required to supply the equivalent of the open cut production. Rail delivery of coal from distant mines is feasible.

The primary objective in development of the Eraring open cut is to utilise an energy resource in the most efficient manner without severe or permanent impact on the environment. The alternatives to mining the resource by the open cut methods would sterilise approximately 37 million tonnes of steaming coal and would impose increased costs on the power station coal supply. The open cut area is at present outside the highly developed areas, however it is anticipated that at some future time development will be likely to spread in such a manner as would prevent the opening of a mine on the site and the coal would be lost for all time. If mining was to proceed as proposed, fully effective restoration of the area would be possible and would permit development of the area to proceed.

During the last year the importance of the Eraring open cut proposal has increased substantially for the following reasons:

I . The succession of oil crises has generated a world-wide demand for steaming coal. Following this increase in demand the value I and price of steaming coal has increased markedly. Steaming coal production from most mines in N.S.W. is at present fully coninitted to existing local and overseas markets and purchase of I steaming coal for use by the Commission in the short term is difficult. In the longer term coal could possibly be made I available from mining companies but only at prices that would reflect the value of coal on the world market.

7 The rapid expansion of the steaming coal market is already taking place and is forecast to increase in the next few years. It will place a severe strain on coal transport facilities. The Commission has already increased the requirement for rail transport of coal to the Central Coast principally to replace supplies that have in the past been obtained from external sources. Additional loading of rail transport facilities which would be required if the open cut proposal does not proceed may be beyond the capacity of the transport systems existing in 1983.

These factors have caused a re-appraisal of priorities for coal supply to the Eraring Power Station with a definite preference for the open cut project because it will make available a low cost dependable supply for power generation. The reliability of the alternatives is prejudiced by the uncontrollable influence of the world energy scene and the increasing coal cost and the reliability of transportation systems.

There are technical problems associated with the development of alternative underground mines. The resources of Great Northern coal in the area are fully committed to mines either existing or under construction and any new mine will be dependent upon the Fassifern Seam as its basic resource. There is only very limited knowledge of mining in the Fassifern Seam in this area and firm estimates of productivity from Fassifern Seam workings will not be available until developments now being planned in existing Commission mines have established the viability of its extraction by underground methods at a reasonable cost. There would be a substantial risk element in committing major capital to a new mine until such time as mining experience in the Fassifern Seam has been gained elsewhere.

There is a cost disadvantage inherent in a failure to develop the open cut resource which has been estimated at $275 million over the life of the mine. The combination of the two underground mines now under construction and the open cut mine is considered to provide a much more reliable source of coal to the power station than any of the alternatives.

[;] SECTION 3 Description of The Proposal I I I I LI I Li LI I I I I El I I I E I 3. DESCRIPTION OF THE PROPOSAL

The Resource

Coal exploration affecting the mine site occurred in four main phases of U drilling. The first drilling in the area was undertaken by the Broken Hill Proprietary Company Limited and was followed by several bores drilled by the Department of Mines from 1950 to 1961. The second phase was carried out on behalf of the Commission, west of the mine site in 1970 and 1971. This phase established sufficient coal reserves to support a power station. The third phase of drilling was completed in 1977. It was undertaken to providedetailed information for planning underground mines, in particular Myuna and Cooranbong Collieries. During this drilling programme it became evident that potential for a substantial open cut coal reserve existed. To that stage only minor coal quantities of the Great Northern and Fassifern Seams were believed to exist in the vicinity of the outcrops. In 1977-78 the fourth stage was undertaken to assess the quantity and quality of coal available for mining by open cut methods.

Coal is to be extracted from the Great Northern and Fassifern Seams of the Newcastle Coal Measures. A typical disposition of these seams across the mine site is shown in the cross section Figure 14• These seams outcrop in the north-western part of the mine site and the area is flanked in the east by the Great Northern Seam workings of the Awaba State Mine.

The seams occur in a gently undulating structure in which the angles of 50 I dip do not generally exceed The site is crossed by one major fault zone which will influence mine layout.

Sediments overlying the Great Northern Seam are mainly conglomerates in the eastern part of the mine site, and sandstones in the west. Strata between I the seams consist mainly of fine grained sediments including shales, mudstones and claystones.

Coal quality of the two seams has been assessed as follows:

I Average ash 23% Average sulphur 0.38% I Average specific energy 23 NJ/kg

A detailed analysis of the coal seams is given in Appendix 1. Mine Plan

The site covers an area of approximately 800 hectares and contains approximately 23 million tonnes of coal in the Great Northern Seam and 27 million tonnes in the Fassifern seam. Extraction of the coal will require the removal of approximately 330 million cubic metres of overburden. Coal production is planned to commence in 1983.

The operation will use draglines, dump trucks, mining shovels, drills, scrapers and bulldozers. A buffer zone shown in Figure 2, approximately 1 km wide is to be established to form a natural barrier between the mining operation, private residences and principal public roads. A 4 km section of the Cooranbong Freemans Waterholes Road will be re-built west of the existing road and the Sunnywood Public School which is on the mine site will be relocated if it is to be retained. It will be necessary to divert Lord's and Jigadee Creeks to the west of the mine site and the new channel and ponding areas will be located in the buffer zone. Clean water storage will be provided along the relocated creek and wildlife will be encouraged by development of wetlands.

In the light of experience gained in the operation of previous projects of this nature and the rapidly expanding body of knowledge relating to environmental protection, mining plans have been developed which will ensure that the development and operation of the proposed Eraring open cut mine will be carried out in an environmentally acceptable manner. All necessary measures to prevent the occurrence of unacceptable levels of disturbance to the environment and to limit the impact of mining to Commission controlled land have been incorporated in the plan proposed for the mine.

The mine site will be bordered by State Forest to the north, Awaba State Mine and Eraring Power Station to the east, Cooranbong Colliery to the south and the strip of land between the mine boundary and the proposed freeway/pipeline route on the western side. The impact of elements of

10 mining such as noise, dust and visual aspect will be reduced or eliminated because of the existence of the buffer zone and screen and land productivity adjacent to the area will not be adversely affected by the mining operation.

Monitoring stations to measure air and water quality and ambient noise levels were established on site to record the existing environmental disturbance. An expanded system to monitor mining activity and environmental elements throughout the life of the mine will be established before mining commences. Pollution from mining activity will be controlled within statutory limits by correlating recorded emissions against activity type and intensity, and regulating the activity or improving the emission treatment to ensure that acceptable levels are not exceeded.

Mine Development (Figure 5)

Administration and service facilities will be constructed just to the west of the mine site and will include:

mine store workshop * car-park bath-house

Coal crushing and storage facilities will be constructed in the south- eastern corner of the mine site.

Mining operations will commence with the excavation of a box-cut along the southern boundary and will advance north from the box-cut.

The mine site will be fenced.

The sequence of mining activities is shown in Figures 6 and 7 and will be as follows:

Vegetation clearing in a strip 50 m wide.

Excavation of topsoil by scraper in the cleared area. The topsoil will either be spread immediately over reclaimed

11 areas or stockpiled as necessary for use in reclamation work at some future time.

Overburden 140 m and more above the coal will be pre- stripped with shovels and dump trucks. It will be spread over the spoil-piles and interburden dumps.

Overburden left after pre-stripping will be removed by dragline. Hard overburden will be drilled and blasted prior to excavation.

The Great Northern Seam will be mined by back-hoe loading dump trucks running on top of the seam. Some parts of the seam will require drilling and blasting.

The interburden between the two seams will be removed using shovels and dump trucks and will be dumped between the spoil-pile peaks and covered with the pre-stripped overburden.

The Fassifern Seam will be mined using a coal shovel and dump trucks.

Scrapers will be used to cover the reclaimed surface with topsoil and the topsoil will be seeded.

The coal will be transported to a coal preparation plant where it will be crushed to -25 mm. Coal leaving the preparation plant will pass to a 5000 tonne final product bin ready for transport by conveyor to the power station. A jig may be installed to clean the coarse fraction of the Fassifern Seam (approx. 2500 t.p.d.). As only the coarse fraction will be cleaned reject will be disposed of in the pit. Water within the cleaning system will be re-cycled.

The characteristics of the Fassifern seam as a steaming coal are not well known. It will be necessary to take a bulk sample from that seam for testing and for that

12 purpose a test pit may be developed in the south eastern corner of the mine site. A test pit in that area would have the added advantage of extracting coal from the proposed site of the coal preparation plant which would otherwise be lost.

Features of the operation will be:

Major equipment (draglines) will operate below natural surface for most of the mine life, thereby reducing visual and noise impact.

. Dumping interburden between spoil-piles and then spreading trucked I overburden will reduce the height of the spoil-piles below that of a total dragline operation. Figure 6 illustrates the principle of over- I burden disposal.

Reclamation will be an integral part of the mining operation and will follow closely (approx. 200 m) behind the excavation activities.

The coal face will advance up dip which will have the beneficial effects of:

- draining water away from the coal face

- maintaining spoil pile stability.

The surface area disturbed by mining at any one time will be limited to approximately 180 hectares, Figure 7.

An officer will be appointed by the Commission to oversee the day to day operation of the project to ensure that mining efficiency and environmental protection are maintained.

An artist's impression, Figure 8, shows the typical mining operation.

13 The excavation of the boxcut will produce approximately 3 900 000 m3 of spoil. Approximately one half of this material will be used in site preparation works for the coal preparation area and services area, construction of embankments for creek diversion works, road construction and other earthworks on site, as shown in Figure 5. Part of the spoil remaining will be used as a screen around the coal preparation plant and as a sight barrier. It will be contoured and grassed in conjunction with the reclamation programme.

It is anticipated that there will be approximately 500 000 m3 of spoil surplus to these requirements and it is proposed to dispose of this material in the "spoil disposal area" shown in Figure 5. The spoil disposal area will be cleared and the topsoil removed and stockpiled. The surface will be prepared and the spoil placed to ensure its stability. After the completion of the boxcut the spoil disposal area will be re- contoured, topsoil replaced and the area revegetated in accordance with the reclamation programme.

Employment

The mine will employ approximately 270 persons as plant operators, tradesmen, labourers and office staff. The workforce will be recruited in the normal manner and will provide substantial employment opportunities for local residents.

The breakdown of employment opportunities is expected to be:

Employment Classification No. of Employees

Administration and Supervision 33 Drilling and Blasting Operators 24 Dragline Operators 14 Shovel Operators 20 Truck Drivers 33 Crushing Plant Operators 6 General Plant Operators 34 Labourers 28 Maintenance Tradesmen and Assistants 78 Total 270

14 Surface Water and Groundwater Control

The Eraring open cut site lies in a catchment area, Figure 9, of approximately 5000 hectares, consequently large volumes of water can pass through the site during periods of heavy rainfall via Jigadee and Lord's Creeks. The low lying areas of the site are subject to regular flooding. Measures will be taken to divert the natural watercourses around mining activity. The course of the proposed stream diversion is shown in Figure 10. The works will comprise embankments across Lord's, Jigadee and Marham Park Creeks as well as channels to convey water from one reservoir to the next. I The system will be designed to handle a 1:100 year flood without overtop- ping the embankinents and spiliways and flood routes for flood capacities in I excess of this will be provided.

Natural run-off from undisturbed areas within the mine site will be diverted away from the area disturbed by mining, by means of contour drains and diversion banks to prevent erosion and to prevent the entry of Un- controlled quantities of water to the mine workings. The course of these internal diversions will alter with progress of mining and changes in natural topography.

Stream diversions will be designed to prevent bank erosion. The banks of the diversion channels will be grassed and the bed lined with graded aggregate, and if necessary concrete or rip rap protection will be installed. The new discharge point into Jigadee Creek will not have an adverse impact on flow in the creek and flood potential downstream from the mine will be decreased.

All water from within the area disturbed by the mining operation, will be retained within the mining area for treatment in sediment traps, oil and grease removal systems and/or chemical treatment plants to ensure that all of the requirements of the Clean Waters Act are complied with prior to its release. With the exception of iron and manganese the metal content of ground water on the site is within the requirements of the Clean Waters Act. Water with a metal content greater than that permitted by law will not be released into catchments until treated. Figure 11 shows the planned water treatment.

15 It is anticipated that the volume of water to be treated will average approximately 3.2 x 106 litres/day made up as follows:

Mine drainage (groundwater + rainfall) 3 000 000 litres/day Sullage, sewage and washdown water (oil bearing) 200 000 litres/day

In the early years of the mine, water collection points will be established at the coal crushing plant. Dirty water will be pumped to the Eraring Power Station ash dam. Surface rim-off will be diverted around the mining operations to the natural water course for the catcbment.

Permanent settling ponds, Figure 12, and water treatment dams will be constructed to store water pending disposal. Water quality in the dam will be monitored.

The settling ponds will be inter-connected and overflow one to another. They will be constructed with sufficient capacity to ensure adequate holding time to permit settling of solids. If necessary a flocculant will be used to assist settling. Each dam will be designed to be isolated from the system for cleaning.

Surface run-off and groundwater which enters the mining zone will be pumped to settling dams.

Groundwater tests carried out over the area indicate low permeability and the absence of major aquifers. There are no problems anticipated with handling groundwater flows into the open cut. Groundwater volume in the alluvium is estimated to be an average of 650 to 1000 litres per day per metre length of exposed alluvium in the pit.

Water collected from the workshops, washdown bay and bath-house will contain organic matter such as oil and grease. Precautions will be taken with lubricant storage and handling, in the form of protective bunds and lubricant dispensers, to reduce the risk of spillage. Run-off from the workshop and servicing area will be designed to deliver to pick-up drains. The drains will deliver to an oil/solids/water separator before discharge of the treated water for use as a dust suppressant within the mine. Refuse

i11 from the separators will be disposed of off the site by waste disposal con- I tractors.

Water discharged from the self-contained sewage treatment system will be used on reclaimed areas. I Water from the preparation plant will be separated from fines in thickeners for re-use. The slurries will be stored in evaporation basins and then disposed of in the pit at approx. 75% solids.

The pH of mine water cannot be accurately predicted until mining operations commence. It is expected to be within the prescribed limits of 6.5 to 8.5. I The analysis of mine water from the adjacent Awaba State Mine shows pH levels within these limits. Regulation of pH, if necessary, can be I achieved by the use of additives.

Treated water will be used on the site for dust suppression and irrigation. I The only fresh water introduced will be for consumption and bathwater; all other water used on site will be re-cycled.

Treatment methods will be implemented to suit the nature of contamination of mine water. Water quality will be monitored after treatment and treated water will only be released from the site if the quality of water in ad- I jacent streams can be maintained within the prescribed limits.

Air Quality Control

Airborne emissions from open cut mine sites can be a source of significant pollution if adequate measures are not taken to control each activity I contributing to air pollution at the source. The greatest potential for air pollution will be from activities which generate dust.

I Measures to control air pollution are well established in practice and have been incorporated into the mine plan. The buffer zone around the mine I boundary is one measure which, with dust suppression, should eliminate dust nuisance on land not under Commission control. Trees and shrubs will be I planted as necessary to complement the buffer zone.

1 17 An air quality monitoring programme at the proposed mine site has been undertaken to provide background data on air quality. The equipment monitors airborne particulate matter on a minute by minute basis and will provide a continuous record of variation in atmospheric content and an immediate indication that dust problems require attention. The programme will also provide a basis for comparison of current air quality and the air quality during mining operations.

The major potential sources of air pollution are:

Primary blasts Excavation of overburden and coal Truck haulage Drilling Spoil dumps Coal crushing plant Coal transport by conveyor Vehicle and earthmoving plant Vegetation disposal

Dust generated from blasting can be controlled by carefully planned blasting practice. The principal dust generators in a blast are an excessive quantity of explosive, shallow depth of explosive in the blast-hole and poor quality material used to cover the explosive. Adequate engineering design, field supervision and use of correct materials in blasting will make a significant contribution to retaining dust generated from mine blasts within Commission controlled land.

Creation of dust by the movement of trucks on haul roads and general transport can be effectively prevented by means of:

Bitumen sealing of major access roads.

Dust suppression on unsealed haul roads by the diligent use of water sprays mounted on tanker trucks. Roads will be watered at a frequency sufficient to maintain the roads in a dust free condition.

Imposition of speed limits. (This is principally a safety measure but also assists in the control of dust).

18 The above controls are expected to eliminate truck haulage as a significant I source of dust generation.

I Blasthole drills will be equipped with dust collectors, regularly maintained, which will effectively eliminate the emission of dust from drilling I operations.

Spoil dumps on the Eraring open cut will not be a significant source of I dust generation for the following reasons:

Efficient blasting practice will reduce the volume of fine material on the spoil dumps.

Rapid reclamation of the spoil dumps will ensure that only a narrow I strip of land is exposed to wind erosion. Recontouring of the spoil dumps is to follow approximately 100 to 200 m behind the active cut.

Spoil-piles will be reduced in height above the natural surface level over much of the open cut because pre-stripped material will be dumped between the spoil-piles and the draglines will generally be operating below surface level. The low profile above natural surface level will assist in minimising wind erosion.

The buffer zone around the mine site will reduce the quantity of airborne dust reaching surrounding properties.

Dust suppression equipment will be installed in the crushing plant from the coal tip to the final product bin and will prevent the emission of coal dust. Water sprays wet the coal at the coal tip and at all potential dust generation sites such as conveyor transfer points and screens. Breaking and crushing equipment will be enclosed and the buildings will be fitted with dust filtration equipment.

Coal transport from the mine to the coal storage area at the power station will be by means of an enclosed conveyor to prevent wind raising coal dust.

All vehicles and earthmoving equipment on site will be fitted with emission control equipment as required by law.

19 Vegetation over the mine area is to be disposed of by selective burning or burial. Timber and brush is to be stockpiled and burned as it is cleared, under favourable climatic conditions, in small stockpiles, to reduce the nuisance created by smoke to a level consistent with rural activity.

Burning will be avoided by burying vegetation beneath spoil-piles when weather conditions would create a smoke nuisance in the district, and when burial will not cause future surface subsidence. Precautions will be taken to keep combustible material away from coal remnants.

Noise

Noise emissions from the Eraring open cut mine will be generated from:

mobile plant coal crushing and coal handling facilities blasting operations.

The noise levels associated with each of the above operations have been determined from measurements at existing Hunter Valley mines. Typical noise levels for equipment used in an open cut are shown in the table below. These values were used to determine the level of noise at the boundary of the buffer zone 1000 metres from the mine boundary.

Noise Level Distance Plant dB(A) Metres

Mobile Bulldozer 63 100 Truck 65.5 100 Scraper 66 100 Dragline 65 100 Rotary Drill 66 100

Stationary Breaker 67 100 Crusher 64 100 Conveyor 57 100

Blasting 94 500

The effect of noise from the site is shown on Figure 13.

Land Management

Land management will form an integral part of the mine production programme and will be based on the following principles:

The area disturbed by the mining operation is to be restricted to the minimum compatible with efficient mining, approximately 180 hectares.

The distance across the operation from tree-line ahead of mining to the reclaimed surface will be approximately 500 m.

As most of the surface will be pre-stripped ahead of dragline stripping and replaced over the dragline spoil-piles the natural upper overburden sequence will generally be maintained.

The interburden (claystone) will be dumped between the spoil-piles and covered with the pre-stripped material. Handling and confining in this manner is expected to eliminate the potential for dispersion of the claystone.

Topsoil will be spread as it is stripped. Small stockpiles will be I necessary inthe early stages of mining, between sowing seasons and when deep topsoil is encountered.

I Box cut spoil will be used for site earthworks such as road construction, stream diversion, earthworks around site buildings, dam construc- I tion and barriers for visual and noise containment. Any spoil remaining will be contoured and seeded along the southern boundary away from I natural run-off channels or placed on the spoil disposal area Figure 5.

I . Any land not required for mining or mine services will be left undisturbed.

I The disturbed land surface will be contoured to a condition compatible with the surrounding region.

. A permanent drainage pattern will be established with capacity to handle I flood discharges.

1 21 Land maintenance will be continued after mining for a time to ensure establishment of the reclamation measures, possibly up to five years.

Erosion will be controlled by:

limiting vegetation stripping to approximately 100 m ahead of mining;

establishing growth on all bared surfaces as soon as seasonally feasible after mining;

establishing contour drains to limit scouring, and directing surface water to watercourses;

limiting slopes to 10 degrees wherever possible;

designing new stream channels to resist erosion.

The Commission will leave the land in a productive condition. Reclamation management will follow the general guidelines outlined below.

The surface will be cleaned of extraneous material and stones with a dimension in excess of 0.2 m will be buried at least 1 m below surface. It is not considered likely that acidic material will be encountered, however, if encountered it will be buried to a minimum depth of 1 m before topsoil is spread. The profile of the surface will be stable, safe and will blend with the surrounding countryside.

Topsoil will be removed to a depth of at least 10 cm and will generally be replaced as it is stripped. Stockpiles of topsoil will only be established at commencement of mining operations and when the depth of topsoil is sufficient to permit stockpiling for later distribution to areas without natural cover. Stockpiles will be of low profile and grassed to limit deterioration and prevent erosion.

Field trials will be carried out with the assistance of consulting bodies to confirm the types of trees and ground cover most suitable for the area. The trials will provide the background necessary to prepare a detailed programme for ploughing, fertilizing, seeding of the topsoil and tree planting.

22 The preliminary vegetation plan is to:

fertilise the topsoil and chisel plough - e.g., Grower 1 (400 kg/ha).

sow suitable grass species such as the following

I - Sirato - Rhodes Grass 1 - Green Panic - Jemalong Medic - Sirocco Phalasis

Grass will be sown from late summer to early autumn.

Fertilise the sown grasses - superphosphate in early autumn. - ammonium nitrate, early spring or mid- I summer Plant trees such as (in irregular woodlots)

- Dwarf Sugar Gum - Cooba Wattle - Forest Red Gum

The new land surface contour will be similar to the old surface but will have less relief and a more gently undulating surface, Figures 124a and 111b. The gentle topography will be more amenable to total utilisation, will have anatural form, will blend with the surrounding countryside and will maintain the natural surface drainage pattern.

Soil quality and productivity on the surface is expected to be improved through the addition of fertiliser, careful soil conservation and erosion control and the reclaimed land will be suitable for grazing or forestry. I The land will be managed after mining for a length of time sufficient to ensure the productivity of the area mined. The expected time period is I approximately five years or until such time that it can be used under normal working conditions without undue deterioration and, in the light of open cut mine experience elsewhere, there is no reason to believe that such a result should not be achieved. This is illustrated by photographs of I reclaimed land at New South Wales open cut coal mines, Figure 15. 23 Slopes will be restricted to within 10 degrees of horizontal with local steepening up to 11 degrees where a 10 degree slope is not possible or where more gentle slopes would result in slope lengths in excess of 60 m. Slopes will be designed to establish permanent drainage with no water- logging or ponding except where permanent water storages are established for stock, irrigation or permanent wetlands.

Use of the final opening has not been decided. It is likely to be used for ash disposal or contoured by blasting and filling the final high wall to produce an undulating surface and possible permanent lake.

As already outlined, a permanent watercourse will be established west of the mine site. The existing drainage slopes and patterns are to be approximated by establishing the final surface contours as illustrated in Figure 111b.

The permanent drainage pattern will reduce flood potential on the mine site and downstream of the site by spreading the flow over a longer period of time than is the case at present. To achieve reduced flood potential, holding dams will be established outside the mine boundary, Figure 10.

All surface facilities and equipment will be removed from the site when mining has been completed. Roads formed for mining purposes will be reclaimed if not required for use.

Hours of Work

The proposed hours of work are as follows:

Land Clearing 1 shift 5 days per week Stripping (shovel & truck) 2 shifts 6 days per week Stripping (dragline) 3 shifts 7 days per week Coal Removal 2 shifts 5 days per week Coal Preparation Plant 2 shifts 6 days per week Drilling 2 shifts 6 days per week Blasting 1 shift 6 days per week Maintenance 3 shifts 7 days per week Reclamation 1 shift 6 days per week

24 IliTi 4Iri 14• STATEMENT OF CHARACTERISTICS AND CONDITIONS I OF THE EXISTING ENVIRONMENT I Theproject area is situated wholly within the boundaries of Lake Macquarie Municipal Council and, under the provisions of the existing planning scheme, the open cut mine site is designated non-urban 'B'. It is proposed that the land affected by the project would be rezoned "Special Industry".

Except for a small area to the south-east of the site, the proposed open I cut mine site lies within the catchment of Jigadee Creek, a northern tribu- tary of Dora Creek.

The ground levels within the site vary from near sea level to about 70 m on the highest ridges near the northern boundary of the site. Most of the site is within the broad Jigadee Creek valley (at elevations between 30 and 60 m above sea level) which lies between the Watagan Mountains to the west and a belt of higher land on the east which is traversed by the Main Rail Line. Northern

The Community

The site is approximately 9 km south-west of Toronto (population 10 000) and 6 km north of Morisset (population 3000). The township of Wangi, with a population around 3000, is about 5 km to the south-east. The population of Toronto increased by 140% in the 10 year period 1961-1971.

The townships closest to the open cut are Dora Creek and Cooranbong, I approximately 3 km and 14 km south and south-west of the mine site. Both townships have populations of less than 1000.

Land and Land Use (Figure 16)

The proposed open cut mine will be sited on land which has been divided I into relatively large allotments. Approximately 140% of the site has been partially cleared and the improved areas are mainly used for grazing. I I 25 I The Great Northern Rail Line passes along the eastern boundary of the site, while the Morisset to Freeman's Waterhole Road passes along the western boundary of the site. There are several local access roads within the project area on the western and southern portions of the site. The central and eastern portion is a part of the Awaba State Coal Mine holding. There are 16 dwellings and one school located within the proposed mining area and buffer zones.

Soils and Geology

Within the project area, the rocks of the Newcastle Coal Measures dip at a slight slope to the south-west. The Great Northern and Fassifern coal seams extend throughout the site. The Great Northern seam is overlain by the Teralba conglomerate and this or the overlying sequence of conglomerates, sandstones and mudstones extends to the ground surface except where overlain by alluvium in the valleys. On the higher land the sedimentary rocks have weathered to a depth of about 4 m and the weathered material is covered by a layer of topsoil about 0.3 m thick. The Fassifern seam is generally located between 3 and 10 m below the Great Northern seam and is separated from it by a layer of claystone.

The site was eroded by streams during previous geological periods when the sea level was up to 50 m lower than at present. The previously formed valleys have been infilled with alluvium to produce the existing broad swampy valleys of Jigadee Creek and its tributaries. The alluvium mainly comprises clay and fine grained silty to clay sand with buried channels of cleaner medium to coarse grain sand which mark former stream locations. The sequence is characteristic of an aggrading meandering creek system within a mature valley. The permeability of the alluvium is low.

A detailed study of the soil over the mine site was carried out by the Department of Agriculture. A soil and slope classification plan, Figure 17, was produced by the Department. (Reference 11).

Samples of overburden, taken from two boreholes, were analysed by ACIRL and the effect of the chemical composition on plant growth and establishment was assessed by the Soil Conservation Service of N.S.W.

Wei The general conclusion to be drawn from the reports is that plant and tree growth can be successfully established over the site as mining progresses. Any material in the overburden potentially harmful to plant growth must be treated or buried.

Climate

The mine location is approximately 13 km north of Munmorah weather station which was established in 1962. The topography surrounding Munmorah and the proposed mine site is sufficiently uniform for the Munmorah meteorological observations to be representative of both locations. Munmorah climatic data is summarised in Electricity Commission Report No. 47/714. Selected information follows:

Rainfall (January 1963 to December 1977)

Average annual rainfall 1176 mm Average annual number of rain days 95 Maximum recorded daily rainfall 153 mm (May 1971) Maximum recorded three day rainfall 331 mm (June 19611)

Dry Bulb Temperatures (January 1964 to December 1977)

Mean of two hourly values 18°C 0 Maximum recorded 43 C Minimum recorded 00C

Wet Bulb Temperatures (January 1967 to December 1977)

Mean of two-hourly values 14°C

27 Evaporation

Average annual (C.B.M. well March 1964 to October 1972) 1362 mm Average annual (Class "A" pan January 1971 to December 1977) 1550 mm

Wind (recorded 12.5 m above ground level, January 1966 to December 1977)

Seasonal and annual wind roses for the above period are given in Figure 18. The wind direction is fairly evenly distributed with calms persisting for about 22% of the time.

Seasonal wind roses are summarised as follows:

Spring - even distribution; 21% calms Summer - dominance of north-east to south; 17% calms Autumn - even distribution; 25% calms Winter - dominance of north-west to south-west; 22% calms.

Aboriginal Relics

Associate Professor L.K. Dyall of the Department of Chemistry, University of Newcastle, has surveyed the project area for archeological sites. The result of this work is presented in references:

Dyall, L.K. (1977). "Eraring Power Station Development Environ- mental Impact Studies: Aboriginal Relics".

Dyall, L.K. (1979). "Environmental Studies (Aboriginal Relics) - Eraring".

Associate Professor Dyall found that the area contains "no major aboriginal campsites, no art, no axe grinding grooves, nor any other important form of relic". He concluded that there was no archeological reasons for objecting to mining in the area by open cut methods. Fauna

The fauna of the proposed mining area has been studied by Associate Professor R.C. Jones and Mr. A.C. Driscoll (Research student) of the Department of Biological Sciences, University of Newcastle (N.S.W.). The results of their work are presented in reference:

Jones, R.C., "Impact Study on the effects on vertebrates of Driscoll, A.C. (June 1977). coal mining for the Eraring Power Station".

Jones, R.C., Clulow, J., "Impact Study on the Effects on Vertebrates of Driscoll, A.C. (May 1979). Coal Mining for the Eraring Power Station".

Eighteen mammal and eighty-three bird species were found or their presence was inferred by observations at one or more of eight sampling sites established within the study area. None of the species found are rare or endangered in New South Wales.

Flora

The flora of the area under review has been studied by Dr. J.C. Turner, Senior Lecturer in Geography at the University of Newcastle (N.S.W.).

The results of his works are presented in references:

Turner, J.C. (1977). "Report on the vegetation on and around potential mine sites north-west of Eraring Power Station, N.S.W."

Turner, J.C. (1979). "Vegetation on and around potential mine sites north-west of Eraring Power Station. Two small additional blocks".

29 Turner classified those parts of the site where the original vegetation is still more or less intact into five categories:

Shrubby open forest Tall open forest Closed forest Open scrub Fresh water swamp These areas make up about 50% to 60% of the site, the remainder has been cleared for farming or other improvements.

The shrubby open forest area is the most extensive of the original vegetation types and occupies all areas away from the valley floors and drainage lines. Several eucalyptus species and an angophora species are dominant. The areas have been selectively logged and are of no importance botanically.

The tall open forest occurs on well drained alluvium along the valleys in bands up to 150 metres wide. The dominant tree is the Sydney blue gum.

The tall open forest merges into the closed forest which occupies narrow bands along the stream banks. Neither of the areas of these classi- fications is particularly rich in species nor well developed structurally, and both have been disturbed by human activity. Both types remain widely represented along the Central Coast.

The areas of open scrub are to be found along the minor drainage channels throughout the shrubby open forest and four areas of several hectares in extent along Jigadee Creek.

The main species present is a Melaleuca and this is overtopped by a scattering of tall trees, mainly Swamp Mahogany. The areas of open scrub in the Jigadee Creek valley are of interest because of an unusual hill and hollow microtopography. The present land use is gradually destroying the biological integrity of these remaining stands.

30 There are several small swamps but the most important (of about 14 hectares in area) is located on the mine site on Jigadee Creek. This swamp is covered largely by a large sedge which grows to a height of about 2 m. The swamp is surrounded by remnant forest and it is considered to be an important wet land. Other nearby fresh water swamps are in cleared country and they are of no interest botanically.

Streamflow and Flooding

Jigadee Creek passes through the mine site. The catchment area at the mine is approximately 146 km2 and this represents about 25% of the total catchment of Dora Creek at the township of Dora Creek, Figure 9.

A stream-gauging station was installed by the Electricity Commission of New South Wales on Jigadee Creek near the Cooranbong-Dora Creek Road bridges in 1969. The gauging station is located downstream from the southern boundary of the site.

The flow duration relationship for the gauging station for the period to 1978 is given in the figure below:

Flow equalled 300 and exceeded Megalitres/ day

100

0 20 kO 60 80 100 % time

31 Flood estimates have been made for Jigadee Creek at the mine site and for Dora Creek at the railway bridge at Dora Creek township. The estimates are as follows:

Estimated Peak Flood Discharges (m3/sec) Flood Return Period Sandy Creek Dora Creek

1 in 2 years 1140 1425 1 in 5 years 195 605 1 in 10 years 240 750 1 in 20 years 260 820 1 in 50 years 320 1035 1 in 100 years 3145 1105

Water Quality

Water quality has been monitored at creek sites in the area of the proposed open cut mine site for Eraring Power Station. The average and range of the results are shown in tables of Appendix 5. See Figure 9 for sample sites.

Suspended solids and five day B.O.D. levels were generally indicative of lightly polluted water for all samples. The dissolved oxygen was generally low, apparently due to the stagnant flow conditions. This condition changes after moderate rainfall in the area.

Air Quality

The Electricity Commission operates a network of 11 particulate deposition gauges within about 8 km of the proposed mine site.

32 The contents of the gauges have been collected at about monthly intervals and the contents analysed and used to estimate deposition rates. The results are summarised in the frequency distribution graph given below.

Particulate Deposition Rates

100 50

Deposition Rate 10 5 gm/m2/month

1.0 0.5

0.1 20 +0 60 80 100

% of monthly samples less than or equal to deposition rate

The average deposition rate in the area is 1 g/m2/month and 5% of the readings exceed 7 g/m2/month. Microscopic examination of the material collected shows that it is mainly natural earth material derived from the surroundings.

In addition to dust particulate gauges a continuous particulate monitor has been operating at the mine site since July 1979. Records to date indicate an ambient dust density in daytime of 10 ug/m3 (Normal Temperature and Pressure).

33 Acoustic Environment

The area surrounding the proposed Eraring open cut mine is essentially rural in character containing hobby farms, larger farming properties and extensive bushland areas. Located in the general area are coal mines, the Eraring Power Station project (now under construction) and major road and rail transport routes.

The area around the mine site can be classified into a number of noise categories on the basis of the existing acoustic environment. These include rural bushland areas with little transport or industrial influence, areas adjacent to roadways with significant traffic influence, areas adjacent to railway lines with significant train noise influence and also areas influenced by industrial development.

The townships of Dora Creek and Cooranbong are approximately 3 to 4 km from the site. A number of isolated dwellings are located to the west and south of the site, adjacent to the Cessnock Road and Great Northern Rail Line, respectively.

Ambient noise level surveys have been carried out at each of three locations which are considered typical of the areas which might be affected by noise from the mine. The results of the surveys are summarised in the following table.

Results of Background Noise Level Surveys at Locations Surrounding the Mine Site

Measured Background Location Noise Level - dB(A) Intermittent Influences Daytime Nighttime

Sunnywood Public School - Cessnock 42 33 Significant vehicle noise Road

Residence - Mt. 39 36 Insignificant vehicle Faulk Road noise

Residence - 143 314 Significant train noise Gradwells Road

34 I

The results of these surveys indicate that background noise levels at locations adjacent to the Cessnock Road, near the Great Northern Rail Line andin bushland type areas, are in the range 33-36 dB(A) during nighttime, and 39_143 dB(A) during daytime. Residences adjacent to the Cessnock Road and Great Northern Rail Line will be subject to the significant influence of vehicle or train noise respectively.

I In terms of the noise area categories defined in AS 1055-1978, "Code of practice for noise assessment in residential areas", the noise levels presented in the above table, and considered collectively, confirm an R2 I area classification ("areas with low density transportation") for the area generally, including those away from industrial or transport developments. I The background noise levels associated with such a classification are 35 dB(A) in the nighttime and 15 dB(A) in the daytime.

At centres of industrial activity such as Awaba Colliery and the Eraring I Power Station construction site the relevant noise category is R3 ("areas with medium density transportation" or "areas with some commerce or I industry" Existing Mine Workings

The coal mining industry has been established in the Lake Macquarie dis- I trict for a number of years.

Newstan, Cooranbong and Myuna Collieries and Awaba State Mine are operating I in the vicinity of the proposed open cut. The two coal seams, Great Northern and Fassifern, to be mined in the open cut are in fact extensions I of seams which occur in nearby Awaba and Cooranbong underground mines, but which cannot be successfully worked, by underground methods, in the pro- I posed open cut area. I

1 I 1 35 nteracflons Between The Project and The Environment 5. INTERACTIONS BETWEEN THE PROJECT AND THE ENVIRONMENT

This section of the statement describes the changes which the construction and operation of the mine may be expected to bring about.

The Community

I Development of the site will require the acquisition of 26 properties including a school. Land acquisition will be made by private treaty when- ever this is possible, Figure 19.

Construction and operation of the mine will provide employment for 270 permanent workers. The mine can be expected to increase the population of the local towns by some 1000 persons. Having regard for the rate of growth already being experienced in the district, this increase is expected to be absorbed in the existing communities without stress to community services.

Land and Land Use

Approximately 320 hectares of land which is now being used for agricultural production will be acquired for the site. It is proposed that those areas which are not required for mining will be leased for grazing or other purposes until required for mining. In this way the loss of agricultural production will be minimised.

Land which has been reclaimed after mining will be suitable for farming forestry or industrial use. The actual use of the land after mining will depend upon its final condition and the decision as to its detailed use will be made at the time it becomes available for these other purposes. It is considered however that the land after restoration will be at least as fertile as at present.

,-a-n6 in the buffer zones will be used for service corridors for a water supply pipeline, access roads, power lines and for the diversion of Lord's I and Jigadee Creeks. Areas not required for these purposes will be left undisturbed and the flood detention basins on the creek diversions are I expected to become valuable wetlands replacing those lost in the existing nttuan vafe;t I

37 Reclamation of mined lands will be undertaken in collaboration with the Department of Mineral Resources and Development and to the advice of the Department of Agriculture, the Soil Conservation Service and the Water Resources Commission.

Aboriginal Relics

Mining will not destroy any known aboriginal relics.

Flora

The existing flora in the mining areas will be destroyed by the mining operations. Wetl and areas will be developed around the re-located creeks.

Fauna

Native fauna will be displaced by the mining operations.

Wetland habitat in the existing valley floors within the mining areas will be destroyed but this will be replaced by the creation of new wetland areas on the stream diversion system.

Water Discharges

Most of the run-off from catchments around the mine site will be diverted around the mining area to minimise the quantity of water entering the mine. Water which enters the mine workings from groundwater seepage or from rainfall on the working and service areas will be pumped to settling dams before being discharged to the Eraring Power Station ash dam or Jigadee Creek downstream of the mine. Water used for dust suppression around the mine will be drawn from the settling basins.

Tests of groundwater quality show that the water from the mine can be expected to be neutral with minor corrections for iron and manganese.

38 The quality of the water in Jigadee Creek downstream of the mine will be 1 monitored throughout the life of the mine and if a deterioration of the water quality due to the mining activity is observed, appropriate action I will be taken to correct the situation.

I Run-off from the contaminated areas around the coal crushing and preparation plant will be treated to ensure quality is within statutory require- I ments before discharge into streams.

Sewage from administration, workshops and bathhouse will be treated in a I sewage treatment plant and the treated water used on site for irrigation.

Flood Control

I The reservoirs formed by embankments across Lord's, Jigadee and Marham Park Creeks, Figure 10, will act as flood detention basins. They will also be developed as alternative wetlands to those on the mine site and can be I expected to provide a better wildlife habitat than Lake Liddell.

Estimated flood hydrographs for the conditions which will prevail after construction of the diversion works have been compared with measured flood I hydrographs (or hydrographs estimated for the measured data) for the gauging station site located on Jigadee Creek downstream of the mine site. The I results of this work are summarised in the table below.

Effect of Flood Control Works on Flood Discharges in I Jigadee Creek Downstream of the Mine Site

Peak Flood Discharge (m3/s) Conditions after Existing Conditions Construction of Control Works 1 in 5 year flood 192 106 1 in 20 year flood 256 143 1 in 100 year flood 341 196

As shown on the table, the proposed permanent works will bring about a I significant reduction in peak flood discharges and flood levels in Jigadee and Dora Creeks downstream from the mine site. The magnitude of the peak

I flood reduction at Dora Creek township will be less than that immediately downstream of the mine because of the effect of the flood storage in the length of the valley between the mine and Dora Creek township. Preliminary estimates of the effect of the flood detention basins on flood levels at Dora Creek township are:

Reduction in Maximum Water Level (mm)

At Railway Bridge At Residential Area Stingaree Point

1 in 5 year flood 70 mm 30 mm 1 in 20 year flood 60 mm 10 mm 1 in 100 year flood 55 mm 0 mm

These values have been estimated for the conditions after construction of the floodway between Dora Creek and Bonnells Bay.

Air Discharges

Dust control planned for the Eraring open cut (described in Section 3) will, in combination with a number of natural features, assist in retaining dust in areas without a residence.

These natural features will assist dust control:

High surface relief to the north, east and west of the mine site and undulating country to the south

State forest to the north, east and west and partially cleared land to the south.

A good annual rainfall.

A fairly evenly spread wind direction.

The prevailing wind is marginally from west to east. To the east of the mine there is an uninhabited zone, 2 km wide, of forest and high relief.

40 Dust monitoring stations will be expanded to provide sufficient information I to develop dust/weather relationships as mining proceeds. Control of excavating, blasting and other dust generating activities will be I engineered to maintain dust at generally acceptable levels.

Measurements of particulate concentrations and deposition rates have been taken at an open cut mine in the Hunter Valley.

The average particulate concentration for the 12 month period of August, 1978 to July, 1979 was found to be 75 ug/m3 for a location 100 m east of the mine boundary. Using dispersion procedures based on the work of Sutton (1947) and allowing for differing meteorological and site factors, the annual average particulate concentration at the 1 km buffer zone boundary of the Eraring mine is estimated to be 25 ug/m3.

The World Health Organisation recommend an annual average for particulate concentration of 40 ug/m3.

In addition to the above a particulate deposition gauge is located 1/2 km east of the mine boundary and has shown an average deposition rate of 2.7 g/m2/month for the period of November 1976 to March 1979. Employing a similar analysis as for particulate concentrations, the average particulate deposition rate at the boundary of the 1 km buffer zone of the Eraring mine has been estimated at 1.5 g/m2/rnonth.

These particulate concentrations and deposition rates are low and considered to be environmentally acceptable.

Disposal of Vegetation

Vegetation will be burnt or buried. Smoke from fires on the site will be controlled by limiting the size of fire and by burning on days with favourable weather conditions.

Noise and Vibration

Based on predicted noise levels for power station and coal mine developments as well as noise level surveys carried out on and near the site, the

41 general area surrounding the mine site has been alloted an R2 category rating in accordance with the procedures given in AS 1055-1978, "Code of practice for noise assessment in residential areas".

The assessment of the impact of noise from the mine is based on the criterion given in As 1055-1978 that an increase of 5 dB(A) above background level will have marginal significance and is not likely to cause annoyance.

The background noise levels for an R2 category are 35 dB(A) for nighttime and 45 dB(A) for daytime. Accordingly, it is assessed that a noise level of 40 dB(A) and 50 dB(A) will be acceptable for nighttime and daytime, respectively, for areas surrounding the site, Figure 13.

Predictions of the noise levels generated from the mining operations have shown that noise levels from mining operations will meet the 10 dB(A) nighttime criterion, provided a buffer zone approximately 1 km wide is established around the areas to be mined. The predicted noise levels generated from the mining operations are shown on Figure 19, together with the proposed boundary of property holdings.

Blasting noise may be audible at some surrounding areas. An assessment has shown that peak noise levels in the vicinity of 85 dB(A) may be expected at the nearest residence outside the proposed mine boundary. Such levels are not excessive and are similar to those produced by trucks and trains along transport routes. The frequency of blasting activity will not be more than one blast per day, and such activity will be planned to occur during daylight hours.

It has been concluded that the proposed blasting control measures at the Eraring open cut mine in conjunction with the selection of property boundaries, will ensure that there are no adverse effects from vibration or noise caused by blasting activities.

To assess the effect of groundborne vibration and overpressure from blasting operations a programme of trial blasts was carried out on behalf of the Commission. The results of the investigation (Reference 9) indicate a vibration level of around 8 mm/s and an overpressure level of 122 dBL at private residences.

42 The safe vibration level recommended by the Australian Standards I Association (AS 2187, Part 2 - 1979) is 19 mm/s. There is no Australian Standard for overpressure, however, the level adopted by the United States I Bureau of Mines is 128 dBL.

Vibration and overpressure levels generated by blasting at the proposed mine will be well within the recommended safe levels.

Transport

Traffic using the access road will increase by approximately 300 vehicle movements each mine operating day on Freeman's Drive. Increased vehicular I activity will be restricted to private vehicles and stores delivery. Access to the mine has been planned to allow traffic to disperse before I entering settled areas. I Coal will be delivered to the power station by conveyor, therefore public roads will not be required to carry coal truck traffic.

Visual Impact

I The area of mining activity will be restricted to approximately 180 ha which will significantly limit the visual impact of the operation. I The mining operations will be visible from the following locations:

Heaton Lookout (6 km to nearest mine boundary),

Morisset (6 km to nearest mine boundary)

I . Dora Creek (3 km to nearest mine boundary) I . Great Northern Railway (100 m to nearest mine boundary)

. Cessnock Road from a point south of the Mount Faulk Road (700 m to I nearest mine boundary)

The mine site is screened from other locations by:

I . Surface relief, Awaba State Mine and Eraring Power Station to the east. 1 43 Awaba State Forest to the north.

A 1 km buffer zone adjacent to the western boundary, purchased by the Commission for that purpose.

Heaton Lookout 6 km from the mine will provide an overview of the entire operation from 350 metres above the mine. It will not be possible to screen the mine, however the working area from a distance of 6 km, will not have a major visual impact. Figure 21 shows the view from the lookout. Tight control on the area disturbed at any one time will ensure a limited visual impact.

The view from Morisset is distant with no impact.

The residents of Dora Creek living along Coorumbung Road will view the open cut from 3 km at the nearest boundary. Equipment will be visible in the south-east corner of the lease.

The Great Northern Rail Line will pass along the boundary of the mine lease. Train travellers will catch glimpses of the mining operations when equipment is working at the boundary. A tree screen and the natural topography will screen the mine from view except for very brief glimpses.

The view from the Cessnock Road at one point is unobstructed . A similar view will be available from the proposed freeway. The mine will be screened at most other points on the Cessnock Road by the 1 km buffer zone. An earthen embankment will be constructed to restrict the visual impact of those areas where no natural barriers exist.

The Commission plans to construct a viewing point and picnic ground near the mine boundary off Freeman's Drive to cater for members of the public interested in the mining operation.

Mine buildings are to be designed to blend with the environment. Wherever possible natural surroundings are to be preserved and trees and shrubs will be planted as necessary to add an attractive surrounding to offices, workshops and plant. Pavement is to be laid in areas such as the approach road to the mine office and the car park and will contribute to an acceptable visual impression and clean environment.

44 I Il .1T.Ii

I L

I I

I 6. ASSESSMENT OF ENVIRONMENTAL IMPACT

The conclusion resulting from the environmental investigations as described in this statement is that the Eraring open cut can be established and operated with minimum impact on the environment by use of the appropriate safeguards and management control.

Dust and noise have the greatest potential for environmental impact. As indicated in the statement planning environmental controls and monitoring the mining operation will provide management with satisfactory control over these two aspects of the open pit operation.

Rare or endangered species of flora or fauna will not be destroyed or displaced by mining.

The visual aspect of the mine and all other elements of an environmental nature will be controlled to produce a negligible impact.

Beneficial aspects of the operation will be utilisation of a resource, job opportunities, improved post-mining land productivity and a cost benefit for power generation.

The project has been assessed by the Commission on the total interaction with the environment. The proposal should not be compared with similar projects of earlier years as it has been planned in order to respond to evolving community standards for such projects and includes a strong emphasis on environmental protection.

Development of the proposal will result in an open pit mine which will impose a subdued impact on the area of the mine site. It will provide substantial short and long term benefits to regional residents in the form of job opportunities, improved post-mining land condition and productivity, a cost benefit for power generation and utilisation of a State resource. The resource should not be wasted in order to maintain an area of low economic and agricultural value in a condition already substantially disturbed by man.

45 The effectiveness of the buffer zone has been estimated from studies made at other open cut coal mines. The buffer distance of one kilometre is a convenient measure for land purchase for the Commission and land holders as it includes all land between the proposed D.M.R. freeway, the oil and gas pipelines and the open cut. That limit on buffer zone width and in fact the necessity for a buffer zone has been made as a judgement by the Commission for the particular case of Eraring and is not necessarily comparable with other open cut mines.

It is considered that the existence of the buffer zone will substantially reduce any possibility that adjacent residents may be exposed to undesirable levels of dust concentration, noise levels or vibration in any given climatic condition.

The effectiveness of such a buffer zone in this regard can only be measured in the light of experience in the conditions at Eraring. As such experience will not be available until after mining has commenced the Commission has selected a conservative boundary limit which will ensure protection of the environment outside the buffer zone from elements of the mining operation.

In addition, the buffer zone is required for relocation of streams, trans— mission lines and Freeman's Drive.

46 SECTION 7 References 7. REFERENCES

Dyall, L.K. (1977) "Eraring Power Station Development Environmental Impact Studies: Aboriginal Relics"

Dyall, L.K. (1979) "Environmental Studies (Aboriginal Relics) - Eraring"

Jones, R.C., Driscoll, A.C. (1977) "Impact Study on the Effects on Vertebrates of Coal Mining for the Eraring Power Station"

Jones, R.C., Clulow, J., Driscoll, A.C. (1979) "Impact Study on the Effects on Vertebrates of Coal Mining for the Eraring Power Station"

Turner, J.C. (1977) "Report on the Vegetation on and Around Potential Mine Sites North-West of Eraring Power Station, N.S.W."

Turner, J.C. (1979) "Vegetation on and Around Potential Mine Sites North-West of Eraring Power Station. Two Small Additional Blocks"

Hannan, J.C. (1978) "Rehabilitation of Coal Mines in the Hunter Valley of New South Wales"

Electricity Commission of N.S.W. Technical Memorandum PD 33. (1979) "Eraring Open Cut Coal Project, Noise Report" (Unpub.)

Wilkinson - Murray Consulting Pty. Ltd. Report No. W 4169-1 (1979) "Eraring Open Cut Coal Project: Blast Control Investigation" (Unpub.)

Electricity Commission of N.S.W. (1979) "Coal Resources - Eraring Open Cut Project Area" (Unpub.)

Department of Agriculture (1979) "Soils and Soil Materials of the Eraring Open Cut Project Area" (Unpub.)

Department of Agriculture (1979) "Soils and Soil Materials of the Eraring Open Cut Project Area - Report on Some Chemical Analyses" (Unpub.)

Soil Conservation Service of N.S.W. (1979) "Discussion of Laboratory Data Obtained From Analysis of Leachates by A.C.I.R.L. - Eraring Prospect." (Unpub.)

114. Sutton, O.G. (1947) Q.J.R.M.S. 73:426-36 "The Theoretical Distribution of Airborne Pollution from Factory Chimneys"

Electricity Commission of N.S.W. Technical Memorandum P.D. 43 (1979) "Eraring Coal Project - Potential Problems Associated with Alluvium." (Unpub.)

Electricity Commission of N.S.W. Technical Memorandum P.D. 61 (1980) "Eraring Coal Project - Groundwater and Permeability." (Unpub.)

47 Append ices APPENDIX 1 INDICATIVE QUALITY OF ERARING COAL (Source: Reference 10)

Great Northern Fassifern Upper Pilot Total Moisture % 7.0 7.0 7.0 Volatile Matter % 26.0 24.0 23.0 Ash % 18.7 25.6 29.0 Fixed carbon % 48.3 43.14 41.0 Sulphur % 0.35 0.140 0.140 Specific Energy MJ/kg 25.0 22.0 21.0 Chlorine % air dried 0.02 0.014 0.02 Crucible Swelling Index 1/2 1/2 1 Hardgrove Grindability Index 148 50 50 Ash Fusion Temperature (°C) Reducing Atmosphere Hemisphere >1560 1560 1560 Petrographic Analysis Maceral Analysis (% by volume) Vitrinite 36 30 - Exinite 6 6 - Inerts 50 514 - % Mean Maximum of all Vitrinite 0.72 0.73 - Analysis of Ash Constituents % Sio2 69.14 69.6 - A1203 22.6 22.3 - Fe2O3 2.98 2.97 - TiO2 1.23 1.06 - CaO 0.32 0.33 - MgO 0.36 0.148 - Na2 0.47 0.73 - K2O 0.62 1.00 - 0.09 0.09 - Mn3O4 0.08 0.03 - SO3 0.25 0.22 - Ultimate Analysis (% d.a.f.) Carbon 82.7 81.8 - Hydrogen 4.92 24.814 - Nitrogen 1.60 1.50 - Oxygen (by difference) 10.27 11.36 - Sulphur 0.51 0.47 -

49 TABLE 1 Results of analysis for pH, conductivity, phosporus, carbon, nitrogen and reaerve potassium of some soils from the Eraring open cut nine site.

DEPTH PH CONDUCT BRAY P SORPTiON PROFILE INTERVAL PART OF (O.O1M (DIST. (ms/CM TOTAL LAB. NO. NO. 1 RATING CARBON NEAP (CM) PROFILE CSCL2 WATER 1:2 NITROGEN C/N RATIO p T 1:2) 1:2) SUSP.) (PPM) (%) (%) (M.E% RIDGE AND UPPER SLOPE 0-9 Al C 79/11+92 4.08 4 .92 0.06 1.2 V.H. 0.091 9-15 Top of C 2.31 25.1+ 1.1+2 79/1493 4.oi 4.86 0.07 0.1+ V.H. 1.00 B hor. 1.88 2 0-9 A her. C 79/11+91+ 4.16 4.91 0.06 0.3 V.H. 0.073 1.17 16.0 1.10 25-35 Top of C 79/11+95 4.08 4.86 0.07 0.1 V.H. B her. 0.76 1.1+3 MID SLOPE 0-1+ Al hor. C 79/11+96 Q•1 3.93 4.72 0.06 V.H. 0.108 3.05 28.2 0.61+ 10-15 Top of C 79/11+97 4.05 4.91 0.08 0.2 V.H. B hor. 1.70 1.01 1+2-1+8 C for. B 79/2759 4.12 4.93 0.10 V.H. 1.70 2 0-6 Al hor. C 79/1498 4.11 4.90 0.05 0.4 H-H 0.061 0.99 16.2 0.53 10-15 Top of C 79/1499 4.13 4.97 0.04 0.2 V.H. B hor. 0.73 0.52 1+8-55 C hor. B 79/2760 4.35 5.35 0.06 V.H. 0.17 LOWER SLOPE 0-9 Al her. C 79/1509 4.59 5.49 0.05 0.9 V.H. 2.03 25-30 B? her. C 7 0.15 9/1 510 4.45 5.28 0.04 0.3 V.H. 0.78 65-73 C hor. B 0.12 79/2761 4.49 5.71 0.04 V.H. 0.16 2 0-9 Al hor. C 79/1503 4.21 5.00 0.06 1.7 V.H. 0.158 2.74 17.3 0.36 28-34 Top of C 79/1504 4.06 5.01+ 0.05 0.3 V.H. 75-82 B hor. 0.62 0.57 75-82 Top of C 79/1 505 3.98 4.69 0.05 1.1 V.H. D bar. 0.18 0.55 51 GULLY ['I 0-8 Al hor. C 79/1500 4.0/ 4.91 0.06 1.1 V.H. 0.102 2.44 23.9 0.31 25-30 Top of C 79/1501 4.13 5.11+ 0.05 0.1+ N 50-60 A2 her. 0.82 0.24 50-60 Top of C 79/1502 4.00 4.49 0.06 0.1+ V.H. B hor. 0.94 0.27 EPHEMERAL SWAMP 0-13 Peaty C 79/1506 4.25 4.87 0.14 8.0 V.H. 0.593 A her. 7.07 11.9 0.80 16-20 Top of C 79/1507 4.21 5.12 0.08 ll V.H. mineral 2.07 1.70 100-105 Mottled C 79/1508 4.05 5.05 0.07 0.3 V.H. subsoil 0.1+4 1.06

Non Exchangeable Available Potassium - referred to as reserve potassium in the text. + V.H. = very high M = moderate H = high N TABLE 2 Exchangeable cations of some soils from the Eraring open cut mine site.

EXCHANGEABLE CATIONS (M.E.%) EXCHANGEABLE CATIONS (% OF TOTAL) DEPTH PANT OF INTERTAL LAB. NO. PROFILE PROFILE Ca Mg K Na Al TOTAL Ca Mg K Na Al

RI3E AND UPPER SLOPE 0-9 Al hor. C 79/1+92 1.01 3.80 0.663 0.36 2.95 8.78 11.5 43.3 7.5 4.1 33.6 9-15 Top of C 79/1493 0.29 4.32 0.692 0.37 > 5.00 >10.67 - - - - at least B hor. 1+7 2 0-9 Al hor. C 79/1494 0.52 2.56 0.376 0.25 2.1+5 6.16 8.4 41.6 6.1 4.1 39.8 25-35 Top of C 79/1495 0.13 3.33 0.428 0.27 4.70 8.86 1.5 37.6 4.8 3.0 53.1 B hor. MiD-SLOPE 0-4 Al hor. C 79/1496 0.49 1.96 0.333 0.27 3.20 6.25 7.8 31.4 5.3 4.3 51.2 10-15 Top of C 79/1497 0.13 4.07 0.459 0.47 5.00 10.13 - - - - at least B hor. 49 42-48 C hor. B 79/2759 0.22 4.12 0.445 0.60 >5.00 >10.38 - - - - at least 48 2 0-6 Al hor. C 79/1498 0.28 0.84 0.166 0.18 0.90 2.37 11.8 35.5 7.0 7.6 38.1 10-15 Top of C 79/1499 0.08 1.14 0.144 0.19 1.25 2.80 2.9 40.7 5.1 6.8 44.5 B hor. 48-55 C hor. B 79/2760 0.03 3.36 0.232 0.24 0.90 4.76 0.6 70.6 4.9 5.0 18.9 LOWER SLOPE 0-9 Al hor. C 79/1509 1.17 1.21 0.247 0.19 0.49 3.31 35.4 36.6 7.5 5.7 14.8 25-30 B? hor. C 79/1510 0.25 1.11 0.035 0.20 0.64 2.23 11.2 49.7 1.6 8.9 28.6 65-73 C hor. B 79/2761 0.03 3.90 0.044 0.31 0.47 4.75 0.6 82.1 0.9 6.5 9.9 2 0-9 Al hor. C 79/1503 1.25 1.63 0.467 0.21 1.20 4.76 26.3 34.3 9.8 4.4 25.2 28-34 Top of C 79/1504 0.60 3.52 0.367 0.31 >5.00 >9.80 - - - - at least B hor. 51 75-82 Top of C 79/1505 0.06 1.81 0.463 0.32 >5.00 >7.65 - - - - at least D hor. 65 GULLY 0-8 Al hor. C 79/1500 0.37 0.99 0.092 0.27 1.25 2.97 12.4 33.3 3.1 9.1 42.1 25-30 lop of C 79/1501 0.03 1.09 0.023 0.31 0.70 2.15 1.4 50.6 1.1 14.4 32.5 Ap hor. 50-60 Top of C 79/1502 0.00 1.76 0.030 0.45 1.55 3.79 0.0 46.4 0.8 11.9 40.9 B hor.

EPHEMERAL SWAMP 0-13 Peaty C 79/1506 4.60 3.07 0.325 0.66 1.25 9.90 46.4 31.0 3.3 6.7 12.6 A hor. 16-20 Top of C 79/1507 1.74 2.71 0.145 0.69 2.70 7.98 21.8 33.9 1.8 8.6 33.9 mineral soil 100-105 Mottled C 79/1508 0.10 5.07 0.1+25 0.72 3.20 9.51 0.1 53.3 4.5 7.6 33.6 subsoil APPENDIX 3

ANALYSIS AND TESTING REPORT - REPORT NO. 02/2583, DATE 10.8.79 BOREHOLE SAMPLES FROM THE PROPOSED ERARING OPEN CUT SITE

SAMPLE PREPARATION

Each sample was over dried at 35°C for 24 hours and crushed to pass 2 mm. An aqueous mixture of one part sample to five parts deionised water by mass was prepared and mixed by tumbling in a plastic bottle, end over end, for half an hour and allowed to stand overnight. All determinations with the exception of pH and Specific Conductance measurements were carried out on the leachate after filtering. Considerable difficulty was encountered in vacuum filtration of the aqueous extract. Most samples took several days to filter.

ANALYSIS

The leachate was analysed in accordance with "Standard Methods for the Examination of Water and Wastewater" A.P.H.A., A.W.W.A. and W.P.C.P., 114th Edition, (1975).

53 APPENDIX 3 (CONTD.)

RESULTS

HOLE 1

Sample 1 Sample 2 Sample -1 Sample 4 pH 8.69 6.46 5.80 9.30

Specific Conductance (micro Siemens/cm) 128 300 275 225

Acitidy to: pH 3.7 (as ppm CaCO3) - - - - pH 8.3 (as ppm CaCO3) 10.0 12.5 20.0 -

Alkinity due to: CO (as ppm CaCO ) - - - 5.5 HC 3 (as ppm CaC 3) 57.0 14.5 9.8 92.3 Chloride (as ppm Cl) 2.7 2.9 3.4 4.2

Sulphate (as ppm 504 ) 16 130 126 85

Sodium (as ppm Na) 7.2 9.2 15.0 40.5

Potassium (as ppm K) 7.2 10.4 11.8 5.9

Aluminium (as ppm Al) 0.40 0.80 0.50 7.2

Silica (as ppm Si) 1.4 1.9 2.1 3.3

Calcium (as ppm Ca) 11.7 21.5 18.4 4.2

Magnesium (as ppm Mg) 2.9 1.1 9.9 1.8

54 APPENDIX 3 (CONTD.)

HOLE 2

Sample 1 Sample 2 Sample 3 Sample 14 Sample 5 pH 5.69 6.91 7.83 6.29 9.21 Specific Conductance (Micro Siemens/cm) 48 205 128 113 173 Acidity to: pH 3.7 (as ppm CaCO3 ) - - - - - pH 8.3 (as ppm CaCO3) 5.0 35.0 25.0 9.5 17.5 Alkalinity due to: CO. (as ppm CaCO) - - - - - HCd3 (as ppm CaC83 ) 8.8 20.3 58.3 30.0 85.5

Chloride (as ppm Cl) 5.8 3.2 3.9 3.7 2.14 Sulphate (as ppm 5014) 10 29 1414 35 28 Sodium (as ppm Na) 8.6 19.3 18.8 16.9 5.7 Potassium (as ppm K) 2.1 6.6 6.14 5.9 2.7

Aluminium (as ppm Al) 0.140 0.8 7.2 1.9 5.6 Silica (as ppm Si) 2.0 1.5 3.8 1.8 2.14

Calcium (as ppm Ca) 0.55 10.1 2.6 2.3 1.3 Magnesium (as ppm Mg) 0.24 14.1 1.9 1.7 1.0

J WILLIAMS

AUSTRALIAN COAL INDUSTRY RESEARCH LABORATORIES LTD.

55 BORE WATER ANALYSIS

THE ELECTRICITY COMMISSION OF NEW SOUTH WALES

CENTRAL CHEMICAL LABORATORY

TEST REPORT

Teat on Bore Water from Eraring Open Cut Mine

The samples were analysed with the following results:

Total Total Total Antimony Arsenic Barium Cadmium Chromium Copper8 Iron Lead Manganese Mercury Selenium Silver Zinc Boron Sample (Sb) (As) (Ba) (Cd) (Cr) (Cu) (Fe) (Pb) (Mn) (Hg) (Se) (Ag) (Zn) (B) (Bore ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm

A23 0.005 0.010 0.5 0.001 0.01 0.01 12.1 0.02 0.53 0.0001 0.0005 0.0005 0.02 o.16

A2 0.005 0.010 0.6 0.001 0.005 0.01 13.9 0.0005 0.09 0.0001 0.0005 0.0005 0.11 0.1+

A29 0.005 0.005 0.6 0.001 0.005 0.02 14.8 0.005 0.11 0.0001 0.005 0.005 o.o4 0.10 A20 0.005 o.004 O.+ 0.001 0.005 0.01 12.9 0.01 0.18 0.0001 0.0005 0.005 o.18 0.18 0.16* A16 0.005 o.004 0.5 0.001 0.005 0.005 7•4 0.01 0.0001 0.005 0.005 0.21 0.07

Demineralised Water 0.005 o.004 0.1 0.001 0.005 0.005 0.01 0.005 O.O+ 0.0001 0.005 0.005 0.01 blank

* Exceeds the filtrable metal concentration specified in the Clean Waters Act, 1970. The total metal concentration was determined as the sample was acidified before filtering. APPENDIX 14 (CONTD.)

BORE WATER ANALYSIS

THE ELECTRICITY COMMISSION OF N.S.W.

CHEMICAL CONTROL LABORATORY

TEST REPORT

A23 A02 A29 A20 A16 pH 6.0 6.0 6.0 6.14 5.1

Conductivity (uS/rn) 81+ 500 15 000 63 500 1+9 500 77 000

Alkalinity to P.P. (ppm CaCO3) 0 0 0 0 0 Alkalinity to M.O. (ppm CaCO3) 70 35 35 30 35 Total Hardness (ppm CaCO3) 110 1+5 105 90 11+0

Calcium Hardness (ppm CaCO3) 30 15 25 35 20 Sodium (ppm Na) 115 71 95 82 108

Potassium (ppm K) 8.6 5.7 6.0 5.0 11+ Chloride (ppm Cl) 200 130 160 180 210

Sulphate (ppm so14 ) 51 73 79 39 57 Silica (ppm SiC2) 21 17 27 31+ 20

Filterable Residue (ppm) 501+ 508 400 577 521 APPENDIX 5

STREAM WATER QUALITY DATA

ERARING OPEN-CUT MINE SITE AVERAGE 28. 2.79 - 13. 9.79

STATION

I I 2 3 4 5

Suspended Solids (mg/L) 15.7 20.8 6.3 9.0 14.3

Dissolved oxygen (mg/L) 3.5 1.0 7.3 3.5 5.1

B.O.D. (mg/L) 2.7 2.3 1.1+ 2.3 1.6

pH 7.0 6.6 7.1 6.7 7.3

Electrical conductivity (us/cm) 1802 291 51+9 205 761+

Total hardness (CaCO3 mg/L) 158 35.1+ 56.9 11.9 111+

Chloride mg/L 1+97 82 161+ 22 162

Silicate (SiO 2 (mg/L) 11.0 2.3 3.? 1.14 14.8

Alkalinity (M.0.) (CaCO3 mg/L) 35•1+ 18.9 22.7 13.1 55.6

Sulphate (so1+ ) (mg/L) 1+9.5 1 10 1 115

Total Dissolved Solids (Calculated from conductivity) mg/L 1153 186 352 131 1+89

Station Key: 1. North of Muddy Lake I Jigadee Creek South of Mine Site Jigadee Creek West of Mine Site 1• Lords Creek I 5. Jigadee Creek at Newport Hoad 59 APPENDIX 5 (CONTD.) STREAM WATER QUALITY DATA

ERARING OPEN CUT MINE SITE RANGE 28. 2.79 - 13. 9.79

STATION

1 2 3 4 5

Suspended Solids (mg/L) 6.8-23.0 2-39.0 1-17.6 2-35.2 0.6-21.0

Dissolved oxygen (mg/L) 0.7-6.7 F0.1-2.9 3.4-5.2 2.0-5.2 2.6-7.5

B.O.D.5 (mg/L) 0.6-4.2 1.4-3.4 0.5-2.3 0.4-5.7 1.1-2.1

pH 6.9-7.1 5.9-6.9 6.4-7.5 5.8-7.3 7.2-7.4

Electrical Conductivity (us/cm) 665-1900 210-383 490-600 52-1010 460-1070

Total Hardness (CaCO3 mg/L) 66-203 24-48 45-70 9-14 55-150

Chloride (mg/L) 184-850 55-100 61-248 12-32 100-236

Silicate (SiO 2 (mg/L) 4.417.2 1.5-2.6 3.4_5.7 0.51.9 4.06.0

Alkalinity (M.O.) (CaCO3 mg/L) 15-60 10-30 15-37 5-30 7-96

Sulphate (SO4) I (mg/L) 21-78 - 5-15 - 50-179

Total Dissolved Solids (Calculated from 424-1220 134-245 313-384 33-650 294-686 conductivity) mg/L 1410 152 I QUEENSLAND I LEGEND - 29 29 11 POWER STATION N.S.W. UNDER CONSTRUCTION / I POWER STATION MAP AREA SYDNEy A COLLIERIES

COLLIERIES UNDER I CONSTRUCTION VICTORIA 36

141 152 t TO \ I I TO MAITLAND

KOORAGAN I ISLAND TO CESSNOCK I MULBRING f A WEST I WALLSEND

EDGEWORTH LE I A BRUNKERVILLE

BOOLAROO I S A FREEMANS I WATERHOLES

TORONTO AWABA I ERARING OPEN CUT A COALMINE \

S ERARING WANG! I COORAN BONG DORA CREEK

I MORISSET

I I ERARING OPEN CUT COAL PROJECT I

A Al WYEE Site Location

PqC\F\O SYDNEY 'TO ONG V Metres 9 6000 Figure I 11 UT COAL PROJECT I

id Environs

0 1000

Figure 21 COORANBONG

MORISSET

ERARING OPEN CUT DORA MINE CREEK COAL MINE H FAD WORKS / QVEYOR URpCE j

COAL -33 MAIN R LREATORAGE N 'I

BONNELLS BAY PORTAL

I ERARING OPEN CUT COAL PROJECT I Locations of Alternative Underground Mine Developments

Metres 01000

Figure 3 1

0 lOPO 0 500 1000 Metres 6( Metres WSTN ... DENOTES WESTERN BOUNDARY OF OPEN CUT COAL MINE ESTN... DENOTES EASTERN BOUNDARY OF OPEN CUT COAL MINE GN _____ F A x ...... , —- x . • .NA). ®.1 A-Z 0 SECTION X-X tw . -4 • '• z H ERARING.2 . . • • . \..___ _' • .___.t Iv

I OPEN CUT I /1 COAL

I I • I S I .5 -7A D, E -. \\\ 1/

' ) ( STORAGE . AREA r-COORANBONG L / COLLIERY/ --- n- SWITCHYARD ERARING PS. LJU ZI / - 40 D E @2 A B 20 0 H P SAMPLE 1 H -20 ., -40 GN I., SAMPLE1 •!. F H.. 9. SAMPLE 2 -60 .. 19 24.68 G.N. It I. H- z] -80 25.74 SAMPLE 3 SECTION Z-Z 28.82F . 28.9 32.76 H 32.38 - SAMPLE 2 NSAMPLE 4 36.05 UP SAMPLE 5 38.38 jISAMPLE 3 Hi 36.24 41.75 .1 — — F 44.75 G.N. 46.81 _SAMPLE 4 47.08U.P LEGEND 52.19 49.45 SANDSTONE 54.89 U.P H i 55.89 57.11 For reference to CONGLOMERATL 48.14F 60.14G.N. ' Holes 1 & 2 see Appendix 3. ' 63.46 [HI SILTSTONE/CLAYSTONE/MUDSTONE I ERARING OPEN CUT COAL PROJECT 6719 F It- 70.35 BANDED COAL 71.07U.P 76.16 - COAL 79.72G.N. Typical Site Geology 82.58 F G.N. GREAT NORTHERN SEAM 86.67 F FASSIFERN SEAM 93.6 U.P UPPER PILOT SEAM 94.2 U.P Metres BORE HOLE LOCATIONS - 400 ELEVATIONS: A.H.D. METRES Figure 4 BSI0 LEVEE BANK

90 ABEP~ SeFMCE

Q DS J/ >

DIVERSION N CHANNEL -0

I \

z LD (I I! -

BOXCUT I' Qc FINAL / / PRODUCT BIN

CONVEYOR FROM COORAN BONG COLLIERY L cc HYARD \lLSAL AREA FOR ERARING OPEN CUT COAL PROJECT / BALANCE OF DELIVERY CONVEYOR BOXCUT SPOFL\ Boxcut, Coal Preparation Plant, Support Facilities and ERARING TATION COAL STORAGE AREA Stream Diversion C Metres LEGEND 0 800

-* WATERCOURSES Figure 5 I

I CULTIVATION TOPSOIL PRESTRIP SPOIL MIDBURDEN DRAGLINE OVERBURDEN DRILLING & PRESTRIPPING TOPSOIL CLEARING RETURN DUMPING DISPOSAL SPOIL PILE STRIPPING BLASTING REMOVAL I

I DRAGLINE CHOP

SPOIL PILE DRAGLINE STABILITY BERM MAIN DIG

GREAT NORTHERN SEAM MIDBURDEN I___ PIT FLOOR - FASSIFERN SEAM

I ERARING OPEN CUT COAL PROJECT I

Mining Operations Typical Cross Section

Metres 0 50 -1 Figure 6 VA CE WOSHOPBH HOUSE & ST0RE .- - ARLA

/ SETTLING HA ROAD / PONDS PRESTh S

IT 'I I I I I / Y1 II I I E-A II I'I I N I' II

0 / LU II ii 0)I IO)° HW LL LUU) L) LU 0

II ilII

LU Ir o r J I I ROAD HAUL /ç

CONVEYOR FROM COORANBONG COLLIERY I) ERARING OPEN CUT COAL PROJECT SWITCHYARD

Ill DEUVERY CONVEYOR O% Mining Operations 'A Plan COAL ERARING STORAGE POWER AREA N TATI Metres 0 800

Figure 7

Jj a, J A D i1G vr

I • i; ojp gSRIrL 47 0 a I 0 Yl 0 1 •E2?L

I SPREADING TOPSOIL F AT AL

RILLING

CULTIVATION \

NSPOILPILES. I \N\ \ AL 1' REMOVALS -- DBURI7 / MI NE ADVANCEj ¼ if k I 10 \ ' SSIFE

I I - - vs - p

•

Af iJ

p 0 0 V 44

4N /7 - -

I I I I I I I A IVILJtJ1'1 I INELLIINU/-\ ,/

RIVER LEVEL / RECORDER / 2 / H EATON /GAP/

DORA / CREEK /' I ERARING _- OPEN CUT L MINE rCCIA ON MUDDY LAKE / / ERARING OPEN CUT COAL PROJECT - \ // GCOAL LEC HIN Catch ment Area WATER QUALITY SAMPLE SITES

Metres 0 100

Figure 9 MARHAM PARK 1'- / CREEK STORAGE

/ CREEK ORAGE /

r7>~ 110 00 : ERARING OPEN CUT Z) ( ) j~ ~ ~ COAVMINE ç I.-

W-4 11

I ERARING OPEN CUT COAL PROJECT I

Stream Diversion and Water Storage

Metres 0 1000

Figure 10 I I I DUST SUPPRESSION RAINWATER I I I I FRE I I I I I I I I

I I ERARING OPEN CUT COAL PROJECT I

JIGADEE DUST I ASH DAM CREEK SUPPRESSION Water Treatment I Schematic I I Figure 11 NATU RAL I OVERFLOW WEIR SURFACE

SECTION A-A I 0 - 25 I OVERFLOW WEIR INTAKE I I 7r I I I POND 1 I I I I U

I LOW I I

WATER DISCHARGE POINT I I ERARING OPEN CUT COAL PROJECT I I I Settling Pond Layout

Metres I 0 100 I I I Figure 12

TO MARTINSVILLE LEGEND Mine working area.

Predicted noise contours - dB (A), shown thus, - Noise contours for mobile plant at an assumed location on the mine working boundary. Contours for trucks on the access road are shown similarly - Envelope of 40 dB (A) noise contour for mobile plant moving to any point on the mine working boundary. - Noise contours for coal crushing and handling facilities. 000RANBONG Proposed boundary of property owned or controlled for the Eraring Open Cut Project. Note: This boundary includes property previously acquired for the Cooranbong Colliery.

Nearest existing residences outside proposed . property boundary.

WYEE -..----- I . _ \ PROPOSED TO MULBRING

401/ SERVICES AR

40 50

- ( ° / I 000RANBONG ERARING .S 40 MUDDY COLLIERY LAKE I 'OPEN CUT MAIN DORA (' - 50 COAL MINE S.. CREEK1&_ 5--- \\ - \\ J60 AWABA STATE I COAL PREPARATION MINE WORKINGS \\ COORANBONG \ PLANT \\ COLLIERY 4/ ' CONVEYO \• \\ ' SWITCHYARD / CONy a LAKE COAL 11 ERARING ERARING a//PS STORAGE ii AREA -I w [ERARING OPEN CUT COAL PROJECT I Q OJ/ 0>1 0 q >- a! Predicted Noise Contours 0/I -- II I' WHITEHEADS LAGOON Metres ASH PIT 0 1000

I! Figure 13 TO WANGI WANGI S \7 "10

01,

40 45 20

I ERARING OPEN CUT COAL PROJECT I

Surlace Contours Pre-Mining

Metres 0 500

ELEVATIONS A.H.D. METRES Figurel4(A) I I I I

5 3 I LU CO CO 345 I j I I I

,50 P

I 50

3 35 I

I ERARING OPEN CUT COAL PROJECT

I Surface Contours I Post- Mining

Metres I 0 500 I ELEVATIONS A.H.D. METRES Figurel4(B) IP

I A'A LEGEND BOUNDARY 000RANBONG - LEASE

COORANBOG UNDERGROUND COLLIERY LEASE

E.C. OWNED a ______LAND E.C. OWNED LAND

FARMILETS FAULK X x x SWAMP x X x x GRAZING x ____ x x x A A1 RESIDENTIAL x x x . cr )< X x x NATIVE FOREST SWAMP x . _____ x x .

I : . SWAMP I • x •. .• . x

x I / . : X-•-.....•• \ • A X

/A 4 x x I I A _ I . • xs.x A COORANBONG" DORA x COLLIERY'j AACREEK L PROPOSED A - —-1--- ERARING I A N OPEN CUT A x A ME A N COAL

X fl A A SWITCHYARD A

0 (

AWABA AWABA COLLIERY o A x g - A A Regional Land Use I

000RANBONG LEASE BOUNDARY I Metres 0 1000 MYUNA - LEASE BOUND - - - \ Figurel6 0 0)O OLUQ %t)

MLS o 26-69+

JF \9+ 35-500+ 35-500+ ) ES 14-1000+

MLS /MLS,-.------ 1 r 26-69+

6-31 30 / 1 us

MLS 25 ' ,-.. MLS 26-69+ 7 26-69+' Cl,. /

355M+

MLS MLS LGUS 69) MLS 26-69+ - 16-31 CUS MLS 5-61 +

CUS )rCO REDDISH 16-31 BETTER\ NSTRLIcTuRED61:100+ NL MLS 26-69+ MLS 26-69+ 130

40 45

LEGEND

PHYSIOGRAPHIC ELEMENTS -

( CUS CRESTS AND UPPERSLI MLS MIDDLE AND LOWER SL( 50 G GULLY in 26-69+ F FLATS - FLOOD PLAIN 45 ES EPHEMERAL SWAMP

I ERARING OPEN CUT COAL PROJECT I

GENERAL ARRANGEMENT OF LEGEND ELEMENTS 6O 0 CRESTS AND UPPER SLOPES 0 Soil and Slope

GUS 6-31 Classification

AVERAGE THICKNESS AVERAGE THICKNESS OF SURFACE SOIL OF SUBSOIL OVER OVER SUBSOIL WEATHERING ROCK Metres (cm) (cm) 0 500

NOTE- PROVISIONAL ASSESSMENT - N.S.W. DEPT OF Figure 17 AGRICULTURE FIELD WORK:- C. HAWKINS AND N. HADDAD, MAY1979.

50 PEAK 50-i PEAK 50- PEAK N N N 59 KM/H 48 KM/H -I 65 KM/H 40 o40 o40 So 50 UJ PEAK PEAK w PEAK Lii NE ul NE 40 NE 59 KM/H D.30 70 KM/H 40 43KM/H 30 Cl) Cl) PEAK co 30 PEAK 30 NW ao PEAK NW 52KM/H 65 KM/H z20 20 20 20 NW 65 KM/H 20 10 20 50 10 50 10 50 10 10 40 40 30 30 30 10 20 10 20 10 20 10 40 20 20 10 20 20 %TIME 20 10 %TIME 10 %TIME 10 20 30 40 50 10 10 20 10 20 30 40 50 10 20 20 10 20 30 40 50 10 10 20 CALMS - (LESS CALMS - (LESS CALMS (LESS THAN 2 KM/H) - 20 PEAK 20 THAN 2 KM/H) 10 PEAK 20 THAN 2 KM/H) 10 PEAK PEAK 10 PEAK PEAK E OCCURRED FOR w 65 KM/H OCCURRED FOR E 58 KM/H 54 KM/H E 65 KM/H 54KM/H 65 KM/H OCCURRED FOR 10 17% OF TIME 20 10 25% OF TIME 20 10 21%OF TIME 20

20 10 20 10 10 50 40 30 20 10 20 10 10 50 40 30 20 IC 10 50 40 30 20 10 10 20 10 20 20 10 20 20 20 20 20 10 20 10 20 10 30 30 30 40 40 40 10 10 10 10 10 PEAK 50 10 50 PEAK 50 SE SE 20 57 KM/H 20 20 43 KM/H PEAK 20 PEAK 20 PEAK PEAK 20 SW SE SW sw 65 KM/H 30 64 KM/H 30 49KM/H 67 KM/H 30 30 30 40 30 40 40 50 50 40 40 40 s PEAK S PEAK 50 PEAK 62 KM/H 50 89 KM/H 50 S 61 KM/H 50

SPRING SUMMER AUTUMN

I FREQUENCY DISTRIBUTION OF WIND SPEED 1966-1977

Clii - - - - I PEAK 89 KM/HR 70--- PEAK PEAK 50 N 65 KM/H 50 N 65 KM/H a Co O 40 40 L Cli 50 PEAK w 50 PEAK a- NE 6O--- NE 36 KM/H 030 40 70KMH 30 40 a PEAK PEAK z 30 30 69 KM/H Z NW 69 KM/H 20 20 NW 20 50------ - 50 10 50 10 10 10 40 40 30 10 20 10 20 40 20 %TIME 10 30 20 20 %TIME 10 20 10 20 10 20 30 40 50 10 10 20 10 20 30 40 50 10 U CALMS (LESS CALMS - (LESS - 20 THAN 2KM/H) 10 PEAK W PEAK 20 THAN 2KM/H) 10 E PEAK W PEAK E 64KM/H OCCURRED FOR 81 KM/H 65 KM/H OCCURRED FOR 91KM/H 10 20 10 22% OF TIME 20 22% OF TIME

20 10 10 50 40 30 20 10 20 10 10 50 40 30 20 10 20 10 20 10 20 20 20 10 20 10 30 30 ERARING OPEN CUT COAL PROJECT I 40 I 40 10 10 10 10 PEAK 50 PEAK 50 SE 20 SE 20 73KM/H PPEAK 73 K M/H PEAK 20 0 20 40 60 80 100 20 SW 30 W 81 KM/H 30 81 KM/H 30 PERCENT EQUALLED OR EXCEEDED 40 30 40 '50 40 40 PEAK S PEAK S NOTE:- ANEMOMETER - MUNRO 59 KM/H 50 89 KM/H 50 LOCATION - MUNMORAH PS. HEIGHT ABOVE GROUND-12.5METRES Wind Roses 1966-1977 ANNUAL WINTER 1 Figurel8

TO 000RAN BONG I ROAD Q LEGEND C C z 0 CROWN LAND I • .1 S... z I 149 S I ç • ELECTRICITY COMMISSION OWNED LAND 199 S ______I •••••• ______205 OF . . ______••. • . • • • CROWN LAND UNDER LEASE S.. • 198. I _ 197. PRIVATELYOWNED LAND PROPOSED •. 193 TO BE PURCHASED 195 : ______190 46 I 6 189 : S • • • • EXTENT OF LANDS TO BE 9 131 • PURCHASED OR LEASED 1 0 11 12 FOR THE ERAR1NG OPEN 345000E I /194 :CUT COAL PROJECT 127. :\ • 130 S • S \, •.. 97 \S , \, • 140 ••.• 45 S 139. S • : 116 , \14 \ 143 C

: TOMULBRING • . •• 209 . 150 119 170 • .1?... 53 N. . \16 21 S 17 222 221 18 98 . . S S • S .• 4 S 70 152 151 S : ••••... S N. • • MUDDY 186 I LAKE 184 5

S PROPOSED. : • N5 \,9 • - S 10 8 • S \ : 187 • • 93 • . OPENS CUT . 5 • • Zo : 92 • 173 • • S S COAL MINE * : • S • S . • _•••••• S I • . . S S 5 S I S S .5 . . S • S 4u,•II\ S I . S S S • S S •

S S S I, S . S S SWITCHYARD S • • I . . * ujIdI1I S 1 • •. .: •

O COAL S • • [~RA—RIN G I • •. • S S AREA •• • GE . S •/ ERARING OPEN CUT COAL PROJECT

• S S •• N . S

S SPU S Land Acquisition .y, •• Metres 0 1000 _ TO WANGI WANGI P Figure 19 ACTIVITY 1980 1981 1982 1983 1984 1985

Tender Period - Tender Selection -

Equipment Orders Dragline 36 months Order to First Dig

Recruit

Boxcut Strip

Coal Production 1.0 X 1Q°t 2.0 X 106t 2.5 X 106t

Land Purchase

Haul & Access Road Construction

Surface Buildings

Coal Preparation Plant

Conveyor 33 Transmission Lines Moved 132 kV 330 kV Freemans Drive Relocated

Creek Diversion

ERARING OPEN CUT COAL PROJECT

Eraring Open Cut Schedule to Production

Figure 20

ERARING OPEN CUT AREA

POWER STATiON SITE LL

'TO BE MINED MINING IN PROGRESS ' RECLAIMED LAND

4 ' mw

1' . - • - •- .( • • •.. - S - S 5 - S. • • .•'S --. . • - S •S -.5 •-. S S • - 5 5' - • W . - • . •.-.,s .!k-, . :- - . 40,, - , • 55 p 1 ni ZI *vg-1 r ' -- • 44 — Y ie it

' St Z. ;• -\\ ; - "\ •' • , • - S ._S_•4• .5. .. S - - S - - -- • S 5 ' 5 , •, 'S. ' " 5 5" 4 . I.. •.5 . - 'I tT 1% 4sl 4 1 .55I5_ 4 5 54 5 5 Ilk Ik ------WOW AMuSS4,

' 4 I sm j "

Aq : I r ' AN " 4 ,

$ f i $ / ; I 4 It

Q a Vow mi

till ' RUN OF MINE RUN OF MINE GT NORTHERN SEAM FASSIFERN SEAM

I I TO ERARING I POWER STATION ERARING OPEN CUT COAL PROJECT Coal Preparation Flow Sheet I (with washery) I Figure22 BOX CUT BOX CUT

CATCHMENT B,IASS - - - rTHICKENER 1 DUMP BREA KER L 1REJECT NULATOR SCREEN

WASHERY USE BO T

STOCKPILE H

,THICKENII n

I L. I BREAKERS k,-./ WASHERY/

Puml--

BIN DELIVERY

TOERANG P.S.

/ 22 k 000RANBONG DELIVERY CONVEyOR T

0 100 Metres

DENOTES DRAINAGE LINES

- -- DENOTES CATCH DRAINS

ERARING OPEN CUT COAL PROJECT

Coal Preparation Plant Layout

Figure 23 tNiiI Lii ii

I I I Page No. I A.1 Geology Addendum 3 A.2 Boxcut Location and Mine Plan Addendum 3

I A.3 Hours of Work Addendum 5 I A.4 Mobile Plant Inventory Addendum 5 A.5 Coal Preparation Plant Addendum 6 I A.6 Mine Water Consumption Addendum 7 A.7 Disposal of Mine Water Addendum 7 I A.8 Stream Diversion and Dams Addendum 9 A.9 Disposal of Vegetation Addendum 10

I A.10 Ground Vibration, Overpressure Levels and Addendum 10 Blasting Practice

I A.11 Sunnywood Public School Addendum 12 A.12 Cooranbong/Freeman's Waterholes Road Addendum 12 I (Freeman's Drive) A.13 Transmission Lines Addendum 12

I A.14 Visual Impact Addendum 12 I 1.15 Ground Water Addendum 13 A.16 Social Impact Addendum 14 I A.17 Noise Level Investigation Technique Addendum 14 I I I I I I I Addendum 1 I 1 9. ADDENDUM The following information is supplied in support of the body of the impact I statement.

A.1 Geology

The proposed mine boundary as outlined in Figure -I is bordered by underground mine workings and proposed workings to the east, south and west and by near surface weathered coal to the north. There is no economical coal above the Great Northern seam on the site. The Upper Pilot seam below the Fassifernis of high average ash content (29%) and is in small quantity with a working section in the order of 1.1 to 0.5 m in thickness. Produc- tion from the seam has not been considered in this statement as the mined quantity will depend on seam thickness, quality, depth below the Fassifern and mining lease provisions. At most it could be expected to contribute in the order of 1% to 2% of total mine production.

Coal below the Upper Pilot seam will not be sterilised by the open cut I operation.

A.2 Boxcut Location and Mining Plan

The boxcut location and mining direction were chosen to:

(a) Provide a stable spoil pile condition. Engineering studies have shown mining down dip on the site would contribute to spoil pile instability I and possible spoil pile collapse. Several weak clay and mudstone seams occur beneath the Fassifern Seam. I These seams have low residual friction angles and pose potential problems for spoil pile stability.

50 The coal seams generally dip at no more than to the south west. I The weak strata below the Fassifern seam combined with the dip direction require that precautions be taken to maintain spoil pile stability. Consequently mining is to progress up dip. Additional I measures such as incorporating a berm in the spoil pile will be implemented to assist spoil pile stability where necessary.

Addendum 3 Generate a minimum quantity of box cut spoil for disposal.

Restrict the volume of water lying against the seam and therefore reduce the contamination effect on the water. This point is of secondary consideration to (a) and (b) and has developed through the need to achieve (a) and (b).

The haul road to the boxcut spoil dump, the spoil dump, the drainage plan and the cross-section of the reclaimed spoil dump are shown on Figure A.1. The spoil dump will not be visible from the rail line or public roads.

The location of the spoil dump was chosen for the following reasons:

The length of haul road is not excessive.

The catchment is small and erosion can be controlled by contouring the dump to drain to a silt trap. Slopes can be limited to low angles.

The area is free from flooding.

The site is over an area previously mined from underground workings.

The area will be screened from view from the rail line. There is no other public access near the dump.

A silt trap below the dump can be constructed with sufficient capacity to provide adequate retention time for suspended solids to settle and to provide for dilution of run-off from the dump.

The spoil dump area is to be stripped of vegetation and the topsoil removed and stockpiled before dumping commences. The completed dump will be contoured to blend with its surroundings, the topsoil replaced and grasses and trees established.

The final products bin will be visible to residents of the district, however it will not be significant in relation to the nearby power station construction.

Addendum 4 A.3 Hours of Work

Shift construction proposed for the mine is shown in the table below: Activity Shifts Days

Land Clearing D MtoF Stripping (shovel and truck) D &A Mto Sat Stripping (dragline) ND& A Sun to Sat Coal Removal D & A MtoF Coal Preparation Plant D & A MtoSat Drilling D & A MtoSat Blasting D MtoSat Maintenance ND&A Sun toSat Reclamation D MtoSat

Key: Shifts Hours

N Night 10.00 p.m. to 10.00 a.m.) Note: Shift to be D Day 6.00 a.m. to 6.00 p.m.) 8 hours within the A Afternoon 2.00 p.m. to 2.00 a.m.) times shown.

M to F Monday to Friday inclusive M to Sat Monday to Saturday inclusive Sun to Sat Sunday to Saturday inclusive

Blasting will not be undertaken on Sunday.

A.4 Mobile Plant Invent

The mobile plant to be used will be at the discretion of the mining contractor, however a probable list of equipment has been prepared as a guide.

Addendum 5 Plant Number Capacity Dragl ines 2 35 to 55 m3 Overburden trucks 10 77 tonnes Coal trucks 6 110 tonnes Front end loaders 2 10 m3 Coal shovel 2 8 m3 Overburden shovel 2 10 m3 Dozer 8 to 300 kW Graders 2 Water carts 3 30 000 L Fuel tankers 2 Maintenance vehicles 2 Drills 127 mm to 310 mm diameter Scrapers 2 20 m3 Tractors 2 Mobile cranes 2

A.5 Coal Preparation Plant

The plant is to be constructed to mining contractor's specifications. A typical flowsheet is shown on Figure 22, layout on Figure 23. Typical plant construction is shown on Figure A.3.

Settling dams for the planned washing plant will not be required as only coarse material of —125 mm to +20 mm size range will be treated in the plant. Fines production will be limited to that produced during the washing cycle and will be approximately 2 tonne/hour. The fines product will be dried and delivered to the final product bin.

The thickener dump is a shallow earth basin designed to safely accommodate the full thickener capacity and is to be used as a receptacle for thickener product in case of mechanical failure of the thickener. The basin will have capacity for the total thickener content and therefore there will be no question of overflow. Disposal from the basin will be to either the preparation circuit or the spoilpiles.

The construction and operation of the coal preparation plant will be required to comply with the following:

Addendum 6 I I Equipment will be enclosed. Construction materials used will be of the standard necessary to I minimise visual impact and blend with the surroundings.

I Conveyors will be constructed with enclosures to a similar standard to that proposed for buildings. I Dust will be suppressed throughout the plant and on conveyors by the I use of water sprays. Drains around the coal preparation area will collect spillage and I washdown water which will be returned to the circuit.

I Noise from the plant will not be a nuisance to district residents as indicated on Figure 13. Enclosing the plant in properly constructed I buildings will control noise at the site. I A.6 Mine Water Consumption The following table is an estimate of the water consumption at the mine I site:

Intake ( Surface run—off 3 000 000 L/day I Groundwater

I Consumption Dust suppression 750 000 L/day Irrigation 250 000 L/day Coal preparation plant I (evaporation) 450 000 L/day

I Release from mine site 1 550 000 L/day

I A.7 Disposal of Mine Water

I All water discharges from areas disturbed by mining operations will be collected and treated to comply with limits specified in the Clean Waters I Act, 1970. I I Addendum 7 Principal water treatment sites will be:

Main settling dams

Box cut spoil disposal area silt trap

Disposal of contaminated water to Eraring Power Station ash dam during early period of mine operation prior to construction of main settling dams.

Main Settling Dams

Settling dams will be constructed as shown in Fig. 12, in the south- western corner of the site. This location is the lowest area of the site and allows drainage by gravity from the balance of the site, except for the south-eastern extremity of the site. Contaminated water will be pumped to the settling dams from that area.

The settling dams have been designed to ensure that contaminated water is retained for a period sufficient to allow the settling of suspended solids so that water discharged to Jigadee Creek complies with standards required under the Clean Waters Act, 1970. The capacity of the settling dams will be 108 000 m3• This capacity is based on a design storm of 76 minutes duration with a return period of ten years and a rainfall intensity of 50 mm/hr. Clean water from the final dam will be used on site for dust suppression, process water in the coal preparation plant, etc.

Boxcut Spoil Disposal Area Silt Trap

A silt trap will be constructed downstream of the boxcut spoil disposal area to prevent transport of unconsolidated spoil into Jigadee Creek (Figure A.1).

The silt trap has been designed to accommodate a storm of 46 minutes duration with a return period of two years and rainfall intensity of 44 mm/hr. It is anticipated that the area will be satisfactorily revegetated within a period of two years from creation of the spoil dump. The designed capacity of the silt trap is 43 000 cubic metres.

Addendum 8 The silt trap is to discharge via a small diameter pipe through the dam wall so that the water level falls to allow the retention of run-off from the design storm for a period of 20 hours after which there is sufficient capacity again available to accommodate the design storm. For run-off in excess of the design run-off a weir discharge is provided.

The volume of water, referred to on page 16, delivered to the ash dam would be a maximum of 14% of the water circulating between the power station and the ash dam. The ash dam and circulating load will be able to handle the additional water from the mine without reaching an overload condition and without danger to the environment. The small volume of water delivered from the mine to the ash dam will not U measurably raise the level in the ash dam.

Disposal to the ash dam is contingent on the settling dams not having been constructed. If the dams have been completed the ash dam will not be used.

A.8 Stream Diversion and Dams

I An engineering design of the stream diversion and dam construction will be undertaken when the project is approved and before mining commences. The design will be in accordance with sound engineering practice and will provide for permanent erosion free structures. Conceptual dam and diversion channel construction has been shown on Figure A.l. The outlet channel will act as a spiliway. An outlet pipe with valve will be installed to provide controlled release of water if required.

Construction of the dams and associated channels will be undertaken over a period of from one to two years and will be carried out to the environ- I mental standards contained in the impact statement. All earthworks and roads associated with the construction will be reclaimed. Drainage water I from the construction phase will be collected and treated before release from the site.

I I Addendum 9 A.9 Disposal of Vegetation

Alternatives considered for vegetation disposal were:

burning burying disposal to commercial interests

The third alternative was favoured and investigated without success, however timber will always be available for commercial use to any consumer.

Burning is the proposed method of disposal. It will be subject to appropriate approvals and suitable climatic conditions to protect district residents.

Burying timber in the spoil pile could result in later surface subsidence as decay takes place.

An open burning order is in effect throughout the district which will require approval to be sought to allow the order to be lifted for disposal of timber on the mine site.

A.10 Ground Vibration, Overpressure Levels and Blasting Practice

Investigations have been carried out on the proposed mine site to provide predicted vibration and overpressure levels expected at private dwellings, the power station, transmission lines and underground mine workings.

The levels expected have been nominated in the body of this report. All levels are within damage and disturbance limits.

The adoption of efficient blasting practice at the mine will require:

Addendum 10 . Blasthole patterns and blasthole diameter to be of a dimension to I provide sufficient explosive to break the surrounding rock to the size necessary for efficient handling of the broken material by the parti- I cular materials handling system employed. An indication of variation in typical explosive density for the Eraring site would be 1.0 kg of I explosive to 1.0 m3 of overburden for a dragline operation and 1.0 kg - explosive 2.0 m3 of overburden for a truck and shovel operation. Overcharging could result in excessive fines, flyrock and overbreak. I Insufficient charge could result in poor fragmentation and blow-out of the charge. I . Location of the charge within the hole to use the power of the I explosive to greatest effect. In general the bulk of explosive is used to break the hardest rock and not wasted on the soft rock in the I same hole. The charge may be decked to reduce the explosive power in conditions where rock strength does not require a continuous charge. These measures will reduce the charge and therefore the overbreak. I

. Stemming of suitable quality in a well designed blast to assist in I containing the power of the explosive within the hole. The result would be less blowout effect at the surface, consequently a reduction I of fines and flyrock.

. Correct sequencing of blasts to eliminate excessive ground vibration, I flyrock and overbreak.

The measures adopted in correctly designed blasts will reduce:

I . noise ground vibration overbreak, flyrock and excessive dust the need for secondary blasting.

Addendum 11 A.11 Sunnywood Public School

The school is a one teacher school with attendance of 9 to 12 pupils. The Commission will offer to relocate the school sometime after mining has commenced if it is open at that time. The Education Department may have made other arrangements for the pupils unrelated to the open cut mine development.

A.12 Cooranbong/Freeman's Waterholes Road (Freeman's Drive)

The existing road is to be re-located west of the mine site. The new road is to be of similar standard to that existing and to parallel the route of the proposed expressway. Construction quality and location will be subject to Department of Main Roads and Lake Macquarie Municipal Council approval. Access to properties will be available as required. Re-location of the road will provide a bushland screen approximately 1 km wide between the road and the mine.

Access to the mine will be from the existing Cooranbong/Freeman's Waterholes Road as shown in Figure 2. The road will be sealed. Other roads on site will be unsealed and of suitable construction to sustain heavy vehicle passage. Construction of the roads will include appropriate drainage, erosion control and silt traps to restrict pollution of water.

The long term future of the road is a matter for decision by the appropriate authorities probably at time of completion of the proposed expressway.

A.13 Transmission Lines

Transmission lines now crossing the proposed mine site are to be re-located as shown on Figure A.l.

A.14 Visual Impact

Figure 21 shows the view to be seen from Heaton's Lookout after approximately ten years of mining. The overlay has been marked to better indicate the disturbed surface. It should be noted that the area under excavation up to the reclaimed surface will be, at maximum, no larger in extent than the area of the power station construction site.

Addendum 12 Figure 21(a) shows the present surface condition with the power station construction site in the background.

Mine buildings, Figures A.2 and A.3, and the mining operation, will be screened from view.

The Commission will reserve comment on the publication "Hunter 2000" and Lake Macquarie Municipal Council's proposed scenic zone and make appropriate submissions, if necessary, to the determining authority.

A.15 Ground Water

Samples of the overburden and interburden have been analysed for effect on ground water and water seepage quality. Two holes were chosen as representative of the material over the mine site, Figure 14, and the results have been tabulated in Appendix 3. [I The results of the analysis indicate pollution from this source will not be a problem. Water from the spoil piles will not contain salts, metals or pH levels which will affect the quality of water off the site. I Groundwater inflows have been calculated with the following results:

Foundation Thickness Inflow (Long Term) I

Conglomerate/sandstone 50 m 1428 L/day/metre length of cut

Claystone interburden if 11 I 5.0 m 93 " " " "

it if it Alluvium 5.5 m 670 " " "

Coal Gt. Northern it I - 3.5 m 242 " " Coal - Fassifern 140 m 97

I Average leakage rates were used for a typical section assuming the water table at a depth of 10 m which corresponds to the measured maximum standing I water levels in the area.

The long term inflow rates were calculated from Dupuit's formula assuming the drawdown effect extending 100 metres from the open cut face. 1 I 1 Addendum 13 A.16 Social Impact

The impact of the open cut workforce on local community services is expected to be minimal because of the large number of residential centres in the area. The Commission will co-operate closely with local authorities and other Government agencies responsible for providing essential services and will assist Government bodies in investigations of the effects on communities of coal mine development.

A.17 Noise Level Investigation Techniques

(a) Measurement of Background Noise Levels

Noise level surveys were carried out on the area around the Eraring Open Cut mine site.

The noise measurement system utilised precision noise monitoring equipment and was housed in a caravan with an external 2140 V a.c. mains power supply. Supplementary heating via two 25 W lights was provided to the microphone assembly to ensure that moisture deposition did not occur and a wind guard and bird protector was fitted. The system was reference checked by using 1214 dB pistonphone and appropriate adjustment for atmospheric pressure variation was applied during the calibration procedure.

During the period of the noise survey, simultaneous records of wind speed and direction were obtained for the purposes of ensuring that prevailing wind conditions did not invalidate the ambient noise results. The equipment used to do this was a self-contained mechani- cally driven Woefle recorder which was mounted on the caravan roof.

Continuous chart recordings of the 'A' weighted noise level - dB(A) were obtained over a period of approximately one week. The chart was examined on an hourly basis from which hourly background noise levels were obtained. The levels selected were visually assessed as the hourly L90 level (90% exceedence). The hourly background noise levels

Addendum 14 were then aggregated for each of daytime, evening and nighttime periods from which average period background noise levels were generated. An examination of the wind chart taken simultaneously with the noise record confirmed that the wind influence during the survey was insignificant.

(b) Prediction of Noise Levels at the Eraring Open Cut Mine

The base data used to predict the noise levels resulting from the operation of the Eraring open-cut mine have been determined from measurements on appropriate plant at existing mines.

The predicted noise levels presented in this report have been predicted on the basis that noise levels will be attenuated by distance, atmospheric and ground absorption. The attenuation effects of topo- graphic barrier have been assessed where applicable and no allowance has been made for effects of trees or foliage.

Addendum 15

/ 30

PLAN A BOXCUT SPOIL DISPOSAL AREA / FBEEWY AND PE / 30 25 30 / 30 OPOSE z uJ < 30 35 40 1/ /Lz s SECTION A-A o THROUGH BOXCUT SPOIL DISPOSAL AREA 0JERS° 45 MARHAM PARK 40 70 CREEK STORAGE 40 45 40/ 35 35

t 35 40 uJ 45 Cr 348000 E uJ JIGADEE SPOIL (C RAP (0 0 CREEK 45 40 3< STORAGE ______ SCALE 1H, lOv w 2 40 35 45 w 0 Ci) 30 - -J 40 LU 0 50 40\ > - 80 45 SPOIL Cr SCALE1H:1V Cit

45 GRADE % 38% 1.4% ERARING OPEN CUT 55 45 FINISHED LEVEL R.L.O. LU QUA 50 55 NATURAL SURFACE LEVEL ( ° RAILWAY Metres 00 50CM bOOM COALMINE 60 RO CD RRY 50 No

0 300 Metres 30

0 133 '(C 110 vo = CHIMNEY DRAIN

40 SOIL

SO K cUT SPOIL SPOSALAREA DRAINAGE BLANKET (see detail plan In HOMOGENOUS FILL and cross section( j 2 SHORTLY WEATHERED TO FRESH ROCK 80 -. SM k—

TYPICAL SECTION STREAM DIVERSION EMBANKMENT TYPICAL SECTION STREAM DIVERSION CHANNEL

-10 10

STREAM DIVERSION 00. EARTHWORK CONSTRUCTION DIMENSIONS (Metres)

LORDS CREEK JIGADEE CK. MARHAM PARK CK. TAIL c ( CREST AL 330 28.0 25.0 24 0 So Metres NATURAL ) BASE RL (SURFACE 25.0 20.0 17.0 13.0 00 BASE WIDTH MAX: 54.0 50 EMBANKMENTS 54.0 54.0 72.0 40 WATER SURFACE R.L. 285 23.5 19.0 - ERARING OPEN CUT COAL PROJECT I CAPACITY (M3) 250000 356000 110500 -

LORDS-JIGADEE JIGADEE-MARHAM FE MARHAM PK.-TAIL Earthworks Detail

TOP AL 43.5 34.5 33.0 CHANNELS BASE AL 27,5 22.5 18.0

MAX. WIDTH 64.0 56.0 62.0

BASE WIDTH 6.0 6.0 6.0 Figure Al WORKSHOP AND STORE TO MINE-

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Services Area Conceptual Looking West

Figure A2 I I I I FINAL PRODUCT COAL TIP BIN I I BRADFORD I THICKENER BREAKERS 17 I 0 0 I r fl ,f •I

I WASHERY SCREEN I HOUSE SCREEN GRANULATORS HOUSE AND TRANSFER HOUSE I RAW COAL STOCKPILE I I I I ERARING OPEN CUT COAL PROJECT Coal Preparation Plant I Conceptual Looking South I Figure A3 NEW SOUTH WALES ELECTRICITY FIR uS Err ino open cut cci orojct a NE1 4 SOUTH WALES ELECTRICITY EIS IIS

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