ES 625
ABO1 9334
Tallawarra Power Station project: discussion document I I I I I I I
I. WOLLONGONG P1 El 11IlllIlIl11 Lake TALLAWARR.40 Illawaira 1, 0
0 SHELLHARBOUR
I El I I P
I ENVIRONMENTAL GEOLOGY SECTION I GEOLOGICAL SURVEY OF NSW, I
ELECTRICITY COMMISSION OF NEW 1 SOUTH WALES I I. I TALLAWARRA POWER STATION PROJECT
DISCUSSION DOCUMENT I 1• I FEBRUARY, 1987
I I I I CONTENTS
I Page No. I INTRODUCTION 3 2. EXECUTIVE SUMMARY 7
2.1 DESCRIPTION OFTHE PROPOSAL 7 I 2.2 ENVIRONMENTAL IMPACTS AND SAFEGUARDS 8
3. DESCRIPTION OF THE PROPOSAL 11 I 3.1 GENERAL DESCRIPTION II 3.2 COALSUPPLY II 3.2.1 First 660 MW Unit II I 3.2.2 Second 660 MW Unit 20 3.3 COALTRANSPORT 22 I 3.4 COAL STORAGE AND HANDLING 22 3.4.1 Power Station Coal Storage 22 3.4.2 Power Station Coal Handling System 23 I. 3.5 CONDENSER CIRCULATING WATER SYSTEM 25 3.6 DOMESTIC WATER SUPPLY 25
3.7 ASH COLLECTION PLANT 25 I 3.7.1 Fly Ash Collection Plant 25 3.7.2 Furnace Ash Collection Plant 25 I 3.8 CHIMNEY 26 3.9 ASH DISPOSAL SYSTEM 26 3.9.1 Ash Storage Sites 26 I 3.9.2 Ash Transport 28 3.9.3 Operation Principles of Proposed Ash Storage System 28 I 3.9.4 Restoration 29 3.10 WATER MANAGEMENT 29 3.10.1 SewageTreatment 29 3.10.2 Construction Drainage 33 I. 3.10.3 Uncontaminated Drainage 33 3.10.4 Contaminated Drainage 33 3.10.5 Chemical Plant Drainage 33 I 3.10.6 Coal Handling Plant Drainage 33 3.11 STORAGE AND USAGE OF HAZARDOUS SUBSTANCES 33 I 3.12 TRANSMISSION 34 3.13 TRANSPORTATION 35
3.14 LANDSCAPING 35 I 35 3.15 CONSTRUCTION
3.15.1 Construction Programme 35 I 3.15.2 Construction Materials 35 3.15.3 Construction Works Facilities 36 3.15.4 EmploymentOpportunity 36 I 3.16 APPRENTICETRAINING 36 I 3.17 LAND REOUIREMENTS 36 Page No.
4. EXISTING ENVIRONMENT 42
4.1 THECOMMUNITY 42 4.1.1 Planning Instruments 42 4.1.2 Population 42 4.1.3 Regional Economy and Employment 42 4.1.4 Commercial and Industrial Facilities 45 4.1.5 Accommodation 45 4.1.6 Community Support Facilities 45 4.1.7 Municipal Utility Services 46 4.1.8 Transport Facilities 46
4.2 PHYSICAL ENVIRONMENT 46 4.2.1 Topography, Geology and Soils 46 4.2.2 Land Use 46 4.2.3 Climate 48 4.2.4 Flooding 48 4.2.5 Archaeology 52 4.2.6 Flora and Fauna 52 4.2.7 Heritage 55 4.2.8 Water Quality of Lake lllawarra 56 4.2.9 Aquatic Flora and Fauna 59 4.2.10 Acoustic Environment 59 4.2.11 Air Quality 62 4.2.12 Minerals 64
5. ENVIRONMENTAL SAFEGUARDS AND IMPACTS 68
5.1 THE COMMUNITY 68 5.1.1 Population and Employment 68 5.1.2 Commercial and Industrial Facilities 69 5.1.3 Community Support Facilities, Services and Housing 69 5.1.4 Transport Facilities 70
5.2 PHYSICAL ENVIRONMENT 70 5.2.1 Land Use 70 5.2.2 Soil Conservation 71 5.2.3 Climate 71 5.2.4 Flooding 71 5.2.5 Archaeology, Flora, Fauna and Heritage 71 5.2.6 Water Quality 72 5.2.7 Aquatic Flora and Fauna 74 5.2.8 Visual Impact 77 5.2.9 Acoustic Environment 80 5.2.10 Hazardous Substances 82 5.2.11 AirQuality 83 5.2.12 Minerals 88
6. CONCLUSION 92
7. REFERENCES 96
APPENDIX A ALTERNATIVE COAL TRANSPORT MODES AND ROUTES 100
APPENDIX B ALTERNATIVE ASH DISPOSAL METHODS AND SITES 104 I FIGURES
3.1 (a) Site Location 3.1(b) Project Works Arrangement 3.1(c) General Station Layout 3.1(d) Station Elevations I 3.1(e) Temporary Facilities 3.1(f) Electricity Generation -Functions of Principal Elements. 3.2.2 Coal Authorisation Areas and Holdings I 3.4.2 Coal Handling Plant Flow Diagram 3.8 Albion Park Aerodrome Obstacle Limitation Surface 3.9.3(a) No. 3 Ash Storage Area Ultimate Development 3.9.3(b) Possible No.4 Ash Storage Area General Arrangement I 3.10 Water Management Principles 3.14 Landscape Master Plan 3.15.1 Project Programme I 3.17 Existing Property Boundaries 4.1.1 LandZoning 4.2.2 Aerial Presentation of Site I 4.2.4 Duck Creek— Estimated I in 100 Year Flood Inundation 4.2.5 Areas Surveyed for Archaeological Study .4.2.6 Areas Surveyed for Flora and Fauna Study 4.2.8 Location of Water Monitoring Stations I 4.2.9 Aquatic Flora in Illawarra Lake 4.2.10 Noise Survey Location Plan 4.2.11(a) Location of Air Quality Monitoring Stations I 4.2.11(b) Wollongong Area Particulate Deposition Rates 4.3(a) Meteorological Data 1972— 1983 4.3(b) Wind Roses 1976— 1983 5.2.8(a) Views of Power Station -East and South East I 5.2.8(b) Views of Power Station -South West and North East 5.2.11(a) Maximum Sulphur Dioxide Ground Level Concentrations with Variations of Chimney Height I 5.2.1 1(b) Predicted Annual Average Particulate Deposition Rate Al Alternative Conveyor Route I B! Ash Disposal -Alternative Sites
I I I I I I. I 1. INTRODUCTION
I The Electricity Commission is currently engaged in planning for the development of a major coal-fired power station next to the existing Tallawarra Power Station on the western shore of Lake lllawarra south of Dapto. In order to assist in this process, it is proposed to undertake a planning focus exercise to advise details of the project to government departments and I agencies, and local government bodies having an interest in the project and to obtain their comments on the proposals prior to finalising the Environmental Impact Statement (EIS).
I The existing plant at Tallawarra Power Station, consisting of 4 x 30 MW )A Station) units and 2 x 100 MW )B Station) units commissioned between 1954 and 1957 and 1960 and 1961, respectively, is approaching the end of its economic life. in order to replace this generating I capacity and at the same time utilise the benefits and potential of a valuable salt water cooling site with established infrastructure and to provide for stability of employment in the power, coal and service industries in the region, it is proposed to install new generating plant I at the site. The proposal involves the construction of two new 660 MW coal-fired generating units together with associated coal supply, ash disposal and cooling water facilities. Coal supplies I for the first unit are to be based upon continued operation of the Commission -owned . Huntley Colliery which currently supplies the existing Tallawarra Power Station. Development of the second unit will be dependent upon the Commission being able to secure further adequate, reliable and economic coal supplies and the development of an environmentally satisfactory means for transporting the additional coal to the power station site. It is proposed to seek development approval for two units but the construction of the second unit will be conditional upon obtaining development approval for the coal supply system I tequired for that unit at some future time when details are available. I The works for which development approval will be sought are: (i) two 660 MW generating units and associated works in the power station island complex. coal conveyor constructed on the transport corridor between Huntley Colliery and the power station. I the coal storage and handling facility at the power station site for two units. the cooling water system for two units. (v) the ash storage facilities at the existing No. 3 storage area and a new storage area to the I southwest of Mt Brown for two units.
The power station EIS will not cover the coal supply and coal transport facilities )including the rail loop) which are required for the second unit.
The expansion of Huntley mine to 1.8 million tonnes per annum will not involve significant I changes to the mine surface facilities other than an increase in the capacity of plant items. The mine has previously produced coal at the rate of about I million tonnes per year and the expansion will not cause environmental impacts different from those which would occur over a larger period of time at the lower production rates. Accordingly, no Environmental Impact I Statement is required for this expansion.
Changes to transmission lines will be covered by a separate Environmental Impact Statement I issued at the same time as the Power Station Environmental Impact Statement so that the two can be considered at the same time.
I The principal aims of the planning focus are: . to provide an opportunity for interactive discussion on the proposal in order to incorporate I in the EIS a consideration of the widest range of views of interested parties: to take account of information received when finalising the proposal details; . to initiate or continue liaison, as the case may be, with other public agencies which may I have a role to play in the development. I I Generation planning studies indicate that new generating capacity to be installed after the completion of the 2 x 660 MW Mt Piper Power Station development will probably be required in the mid 1990's. Because of the long lead time involved in obtaining approvals and undertaking the design and construction work involved in a new power station of the size and complexity of the Tallawarra development, it is necessary to undertake basic planning and environmental studies at this time.
Following completion of the EIS it is the Commission's intention to lodge a development application for the proposal, for determination in accordance with the provisions of the Environmental Planning and Assessment Act. I LI
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I 2. EXECUTIVE SUMMARY I This section summarises the main features of the project together with a brief description of the existing environment and interactions which may be expected to result from the implementation of the project.
I 2.1 DESCRIPTION OF THE PROPOSAL
The proposal is to install two 660 MW coal-fired generating units at Tallawarra Power Station, I together with associated facilities required for power station operation. The power station main plant items and important structures include the turbine house, boiler, cooling water intake and outfall canals, fly and furnace ash collection plant, chimney, I coal transport and handling systems and transformer yard. Other facilities will include water storage tanks, oil storage tanks, workshops, stores, amenities and administration buildings.
Coal supplies for the first unit are to be obtained from Huntley Colliery. The mine presently I produces up to 500 000 tonnes of coal annually and it is proposed to increase the output to approximately 1.8 million tonnes of run-of-mine coal annually. I It is proposed at this time to transport coal from Huntley Colliery to the power station by conveyor but investigations are proceeding into the practicability of pipelining. Other .optionswhich have been studied are also discussed in an appendix to the document.
I It is not possible to develop Huntley Colliery to supply coal for a second generating unit and, accordingly, coal supply for the second unit would have to be obtained from other sources. These sources, yet to be defined, would most likely utilise the existing transport I infrastructure of the region and may require the construction of a rail unloading facility near the power station.
Coal storage at the station will be located on the reclaimed Nos. I and 2 ash storages on the I northern side of Wollingurry Creek.
Ash from the combustion of coal in the station's boilers is proposed to be stored in a dry land fill emplacement at the existing No. 3 ash storage area and at an area on the power station I site south of Mt Brown and east of the F6 Freeway. Other options for ash disposal have been studied but investigations carried out so far have indicated that the total volume of ash production over the life of the machines to be installed in the 1990's can be disposed of I almost entirely within the existing site boundary. Cooling water will be drawn from and returned to Lake Illawarra as is presently the case with the existing power station. Cooling field studies have demonstrated that the lake is adequate I in size for this purpose. The cooling water system will be designed so that there is no adverse effect on the aquatic environment within the lake.
Fresh water will be supplied from the Metropolitan Water Sewerage & Drainage Board system I in the area.
Particulate matter contained in the flue gas from the boilers will be removed by passing I through high performance fly ash collection plants. No major new transmission lines are required to be constructed in the region to service the project. The power station will be connected to the existing Dapto 330 kV Substation by I constructing a short length of new double circuit 330 kV transmission line and some minor rearrangement and dismantling of existing 132 kV circuits will be carried out.
Access to and egress from the station will be via the Princes Highway utilising safety features I in accordance with DMR requirements. With the exception of the coal transport corridor, the possible rail facility, and small strips of land near Mt Brown and No. 3 Ash Storage, all works would be located on existing I Commission-owned land. When the new plant is placed in full operational service the existing plant will be withdrawn I from service and retained for experimental and emergency use only. The building works H associated with the new unit will be planned to allow continuous operation of the existing station during the construction phase.
The project will include all works and measures necessary to protect the existing environment, and will include extensive landscaping and tree planting.
2.2 ENVIRONMENTAL IMPACTS AND SAFEGUARDS
Below is a summary of changes of significance to the environment which may be expected to result from the construction and operation of the power station. Appropriate environmental safeguards have been incorporated in the proposal to mitigate potentially adverse impacts.
The Community
During construction of the power station, a transient workforce peaking at approximately 1400 persons will be required, a significant proportion of whom are expected to be drawn from the I Wollongong sub-region. The existing workforce of about 700 persons at the power station and associated colliery will I increase by about 100 persons as a result of the project.
The additional generating capacity will constitute a component in an industry vital to the economic well-being of this State.
Economic benefits from the project will flow to the region, both directly and through the application of the multiplier effect. I Physical Environment
The works will be designed to be above the one in 100 year flood level and will be such that existing flood levels beyond Commission boundaries will not be increased. The project will not pose a threat to any rare or endangered species of flora, fauna, heritage I items or archaeological sites.
Extensive studies of other operating power stations allow the conclusion to be drawn that the Tallawarra project cooling water discharges will have an insignificant impact upon lake water quality. Aquatic life and plants should remain essentially unaffected. All aqueous discharges will meet the requirements of the State Pollution Control Commission.
Drainage and process water will be treated to ensure maximum reuse and that no adverse impacts of any significance will be caused.
Some visual impact is inevitable, but studies show that the proposal will not greatly alter the visual amenity of the location in the majority of cases. An extensive landscaping programme is proposed.
The noise impact of the project, both during the construction phase and the operational phase, is predicted to be acceptable. Operational details and equipment will be selected to I meet the requirements of the State Pollution Control Commission.
Gaseous and particulate emissions from the chimney will meet the licensing requirements of the State Pollution Control Commission and will be environmentally acceptable.
Appropriate measures will be adopted to control fugitive dust from coal and ash handling and storage areas and based upon experience with these measures at existing power stations, fugitive dust will be controlled to levels which do not damage the environment.
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I 3. DESCRIPTION OF THE PROPOSAL I 3.1 GENERAL DESCRIPTION
The project will involve the installation of coal-fired electric power generating plant at the I Commission's Tallawarra Power Station, which is located as shown in Figure 3.1(a). The new plant will comprise two 660 MW generating units, together with ancilliary facilities. The main plant and ancilliary facilities will be located within the existing power station site, immediately adjacent to the existing power station. Figure 3.1(b) shows the project works I arrangement and Figure 3.1(c) gives the general station layout and shows the main plant areas and important structures including the turbine house, boilers, cooling water intake and outfall canals, ash collection plant, chimney, coal handling plant and transformer yard. Other I facilities will include water storage tanks, oil storage tanks, workshops, stores, amenities and administration buildings. Figure 3.1)d) shows elevations of the proposed station.
The construction phase of the project will involve a variety of temporary works including I contractors' offices, amenities, carpark, construction area, and plant storage and assembly area, as well as offices and carpark for the use of the Commission's construction supervision staff. In addition, a temporary coal storage area will be established. The areas reserved for I these temporary works are shown on Figure 3.1(e). The function of each major element in the station is shown diagramatically on Figure 3.1)f). Coal from the mine or coal storage area is transported within the power station to the coal bunkers by conveyor and then fed to pulverisers to be finely ground before being burnt in the boiler furnace. After combustion, the unburnt residue in the form of furnace ash and fly ash is collected and transported to the ash storage area. The hot gases exhausted from the furnace are discharged via the fly ash collection plant to the atmosphere through a chimney. The coal I supply and the ash collection and disposal systems are important features of the project and are described in more detail later. I Steam from the boiler, after passing through the turbine, will be condensed to water of high purity in a heat exchanger )condenser) and returned to the boiler with the addition of any specially purified water necessary to make up for losses. Heat rejected in the condenser is I carried away by the circulating water system and dissipated in Lake Illawarra. The steam is used to drive the turbine which in turn drives the generator. The electricity produced at generator voltage is transformed to system voltage and then fed to the I interconnected transmission system. Aspects of the proposal set out in this section have been discussed, or are currently under ' discussion, with a number of Government and other bodies. These include the State Pollution Control Commission, the Department of Environment and Planning, the Depart- ment of Main Roads, the State Rail Authority, the Metropolitan Water Sewerage and Drainage Board, the Federal Department of Aviation, Shellharbour and Wollongong Councils and Lake I Illawarra Management Committee.
3.2 COAL SUPPLY I 3.2.1 First 660 MW Unit
The coal source for the first unit will be the existing Huntley Colliery, the output of which will I be expanded by the introduction of longwall mining techniques from the current 0.5 million tonnes of washed coal per year to approximately 1.8 million tonnes per year of raw coal, sufficient to provide for the operation of a single 660 MW generating unit. A total of 70 million tonnes is estimated to be needed to fuel one unit for its operating life.
The expansion of the mine and associated facilities will involve only minor changes to existing surface works. The colliery has in the past produced coal at the rate of up to 1.0 I million tonnes annually.
I II Newcastle I
TALLAWARRA POWER PROJECT I Sydney Site Location & I Wollongong FIGURE 3.1.(a) MAP AREA I
Reproduced by permission of the Director, Central Mapping Authority of NSW. U I I I
.NX/Py :-• •'\ I r / Huntley Colliery Washers
New Possible Units Future No.4 cotr/o Ash Storage - r Possible Railway Loop yyJe40S I .,.-- Coal / Storage Area No.3 Ash I Storage C Al Db /.) Or cs
0 1 km . •. ----- •/ .1 / ,./.-- .1 .. f L :... .- •- / I
TALLAWARRA POWER PROJECT Project Works Arrangement
FIGURE 3.1.(b)
Reproduced by permission of the Director, Central Mapping Authority of NSW.
-'WATER STORAGE TANKS -e
CHIMNEY FLY ASH COLLECTION PLANT COAL STORAGE ELECTRICAL SERVICES CENTRE /I AREA (A & B U N ITS BOILER TURBINE HOUSE TRANSFORMER MISC. WORKSHOPS AND OFFICFS COMPRESSED AIR PLANT FUEL OIL HYDROGEN STORAGE TANKS ¶iijL/ S DEMINERALISING PLANT 12 n WATER MANAGEMENT PLANT SCREEN MOUNDING AUX p66 COAL TRUCK WASHING STATION CW CO(LING 4 FLY ASH HOPPERS COAL TRUCK ROAD HOPPERS SETTLING BASIN CAR PARK
'4,ç4 ROP0 n COAL STORAGE AREA 0i.
TALLAWARRA POWER PROJECT
General Station Layout
FIGURE 3.1.(C) Metres
160
lao
120
100
80
60
40
20
0
END ELEVATION
Metres
160
140
120
100
80
60
40
20
0
FRONT ELEVATION TALLAWARRA POWER PROJECT
0 20 40 60 80 lOOm Station Elevations
FIGURE 3.1(d) TO STATE INTERCONNECTED TRANSMISSION SYSTEM
IL? I)I 1 JI J.)rL. .1
TALLAWARRA POWER PROJECT Electricity Generation Function of Principal Elements FIGURE 3.1(e) L / IY' /1 4f /ir'% /
Reproduced by permission of the Director, Central Mapping Authority of NSW.
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CONTRACTORS STORAGE AND ASSEMBLY AREAS CONTRACTORS ELCOM AMENITIES CONSTRUCTION OFFICES & / CAR PARK
CONTRACTORS HN STORAGE AND CONTRACTORS ASSEMBLY OFFICES AREAS CONSTRUCTION AREA CONTRACTORS CAR PARK CONCRETE BATCHING PLANT
EMERGENCY COAL STORAGE
0 200 400m
TALLAWARRA POWER PROJECT
Temporary Facilities
FIGURE 3.1(f) Reserves to meet the requirements of the first unit are contained in the Wongawilli and Tongarra Seams. They are included in the reserves remaining in the present colliery holding and those in Authorisation No. 298, much of which is now covered by Coal Lease No. 266. Recoverable reserves of 73 million tonnes have been estimated for these seams in the Colliery holding and Authorisation No. 298.
Given the geological complexities of the area, the presence of such features as the Avon Dam, the escarpment and the railway, an overall recovery factor of 40% has been assumed in assessing the available reserves.
Table 3.2.1 gives indicative properties of raw coal from the Tongarra and Wongawilli Seams.
TABLE 3.2.1
INDICATIVE COAL PROPERTIES
WONGAWILLI SEAM TONGARRA SEAM Raw Coal Raw Coal Analysis )air dried basis) Moisture % 1.2 1.3 Ash % 35.9 32.9 Volatile Matter % 22.3 20.1 Fixed Carbon % 40.0 46.0 Total Sulphur % 0.38 0.46 Chlorine% 0.01 0.02 Fluorine % 0.0070* 0.0066*
Ultimate Analysis Carbon % 52.2 55.3 Hydrogen % 3.4 3.3 Nitrogen% 1.0 1.0 Specific Energy (MI/kg) 21.0 22.5 Hardgrove Index 59 59 Ash Fusion )°C) 1430 1480 (Hemispherical)
Analysis of Ash % Sift, 75.7 71.8 Al10 15.1 16.2 Fe20, 5.76 6.67 CaO 0.25 1.01 MgO 0.35 0.60 Na,0 0.09 0.12 K 20 1.09 1.23 Ti0., 0.66 0.75
Mn04 0.15 0.16
SO 3 0.09 0.81 F20 0.042 0.054
* These figures were taken from washed coal samples.
3.2.2 Second 660 MW Unit
It is estimated that coal reserves in the southern coalfields are such that there is ample capacity to supply coal for a second 660 MW unit at Tallawarra and any shortfall in coal supply which may occur from Huntley Colliery for the first unit.
One option for the supply of coal to a second unit is for the Commission to obtain access to Commission held Authorisation 231 and the remainder of Authorisation 298 and the development of a new mine. The extent of these Authorisations and their location relative to Huntley Colliery are shown in Figure 3.2.2.
20 This map is Crown copyright and has been reproducedbypermissionoftheDirectorDivisionof National Mapping Department of Resources and Energy, Canberra Australia N K
HUNTLEY A.298 WASHERY fl TALLAWARRA POWER STATION
07
71
5km E
LEGEND TALLAWARRA POWER PROJECT COLLIERY HOLDING Coal Authorisation Areas COAL and Holding AUTH 0 RI SATIO N BOUNDARY FIGURE 3.2.2 I Another option is for the Commission, at an appropriate time, to invite tenders for coal supply for the second unit, with a specification aimed at drawing the largest market response possible. Subject to the demonstration of being able to meet the requirements of adequate, I reliable and economic supplies and an environmentally acceptable transport method, the coal could come from one or a number of existing collieries. I 3.3 COAL TRANSPORT
I It is proposed to transport raw coal from Huntley Colliery to the power station by belt conveyor. It is intended to retain the existing conveyor from the colliery to its associated nearby washery. The washery will contain a transfer station ad the coal will be transported I from there to the coal storage area at the power station by conveyor along the route shown in Figure 3.1(b). The alternatives to this proposal are discussed in Appendix A, with reasons for their rejection and for the selection of the proposed option. I The Commission is also actively investigating the practicality of transporting coal from Huntley Colliery to Tallawarra using a pipeline. Adoption of this method would provide significant environmental advantages, but while there are a number of coal slurry pipelines in operation throughout the world, there are many practical details to be evaluated before a I decision can be made to adopt this method. The Commission is proceeding to install a pilot plant between Huntley and Tallawarra with the object of obtaining sufficient operating experience on which to base a decision to adopt pipelining.
Coal from Authorisation Nos. 231 and 298 could be transported to the power station using trucks on private haul road, conveyor, or by coal slurry pipeline. The advantages offered by pipelining are such that, if it were demonstrated to be practical and economic, it would be the I favoured transport method for transferring coal from these areas to Tallawarra. It is envisaged that the transport of coal from private sources would in almost all cases require the use of rail transport and hence there could be the need to construct a rail receival I facility near the power station. Coal would be carried by rail on the Illawarra line to a rail 1oop located west of the railway line and near Dapto Substation (see Figure 3.1(b)). A coal conveyor would transport the coal from the receiving bin at the rail loop to the pow, I station's coal handling plant. To provide the station with an alternative means of supply in the event of an extended conveyor breakdown or similar contingency, it is proposed that trucks would supply the coal I needed to keep the station operational. Experience at other power stations has demon- strated the need to provide for trucked coal to cover unforeseen circumstances.
3.4 COAL STORAGE AND HANDLING
I This section deals with the storage and handling of the coal for both units after it has been transported to the station.
3.4.1 Power Station Coal Storage
Three types of storage facilities will be provided for coal supplies to the new power station, I namely an open compacted stockpile, a weather protected bunker and the boiler bunkers. These storages provide "surge" capacity between the coal supply system and the power station and must be provided to cater for miners holidays, fluctuating generation require- ments, plant failure and other contingencies. A temporary stockpile will also be provided to I supply the existing 'B' station during the construction period.
Approximately eight hours storage will be provided in bunkers located between the boiler I and turbine house, similar to those provided at other power stations. Approximately two days supply, that is about 30 000 tonries, will be stored in a weather protected bunker located within the long term coal storage area. I 22 u P H Up to three months supply will be stored in open compacted stockpiles in the long term storage area located on the reclaimed ash storage areas Nos. I and 2 (see Figure 3.1(b)). Provision will be made to extend the long term storage area if required to provide emergency coal storage during an extended outage of the power station.
Careful management of the long term stockpile will be necessary to achieve effective control of dust and to minimise spontaneous combustion. Stockpiles will be "dressed" to provide an even surface which will shed rainwater to the drainage system and thereby minimise the ingress of water to the stored coal.
The use of rubber-tyred plant to transport and compact coal is considered essential to provide the degree of compaction necessary to prevent spontaneous combustion in the relatively longterm storages needed at power stations. Large rubber-tyred plant is used successfully at the existing Tallawarra station and at other Commission power stations for this purpose. While the continual movement of such plant over the storage area to deposit and reclaim coal and to keep it dressed and compacted does not permit the extensive use of bitumen sealing to suppress dust, other effective measures to contain and suppress dust will be taken. These are elaborated upon in section 5.2.11.
The coal storage area will, for the most part, be screened from the surrounding area by means of landscaping and tree planting. I
3.4.2 Power Station Coal Handling System
Although the detailed design of the coal handling system is yet to be determined, the essential elements are known. The station coal handling plant will comprise bins, transfer station(s), mobile plant, mechanical stacking and reclaiming plant, and a weather protected bunker.
A flow diagram of the coal handling system is given in Figure 3.4.2. I Coal coming into the power station will be deposited in the storage area or fed directly to the boiler bunkers, depending on operational circumstances.
A receiving bin for the coal delivered from Huntley will be provided either in the coal storage area or, if a rail loop is built, near the loop. A conveyor will link the bin to a transfer station which will be capable of directing the coal into the coal storage area or to the boiler bunkers.
As indicated in Section 3.3, provision will be made for coal to be trucked to the station and accordingly a truck receival facility, incorporating a truck wash, is proposed near the northern end of the No. 3 Ash Storage area, as shown in Figure 3.1(c). Coal from this facility will be carried by conveyor to the transfer station referred to above and diverted from there to either the boiler bunkers or to the coal storage area.
Coal going from the transfer station to the coal storage area will be carried by conveyor to the weather protected bunker. As indicated earlier, this bunker will have a storage capacity of about 30 000 tonnes. Stackers will move the coal to the non-compacted coal dry storage area within the bunker or to the long term storage area outside the bunker. Reclaimers will take coal from these areas, as necessary.
The reclaimers discharge their load to conveyors which carry the coal to the boiler bunkers. These conveyors are necessarily elevated to reach the boiler bunkers. They will be placed in steel framed structures with metal roof and wall sheeting. Where they pass over areas used by personnel, concrete floors rather than steel grids will be used. The structures will be designed to meet SPCC approval.
I I 23 I I I POWER STATION1 BOILER BUNKERS I _ 1111111 LI
I COAL FROM RAIL LOOP AND/OR HUNTLEY TATION I CONVEYOR
A ROAD RE C El VAL 00 HOPPER I I
I WEATHER PROTECTED I LEGEND COAL STORAGE CONVEYOR Al II COALOAL RECLAIM STACKING OUT V
COMPACTED LONG TERM COAL STORAGE I
TALLAWARRA POWER PROJECT Coal Handling Plant Flow Diagram
FIGURE 3.4.2 I 3.5 CONDENSER CIRCULATING WATER SYSTEM The condenser circulating water system will be similar to that employed for the existing I station at Tallawarra. Water will be drawn from Pithungnar Bay through an intake canal about 500 m long at a maximum velocity of approximately 0.6 m/sec. The circulating water will be pumped through the condensers and returned to the lake via the existing unlined outfall canal which will be extended by approximately 550 m. Both the length and direction of the inlet and outlet canals have been set to minimise recirculation of warm water.
The flow of circulating water will be normally about 21 mVsec per 660 MW unit, depending on the design of the turbine and condenser selected. When necessary, the water in the outfall I canal will be "attemperated" (i.e. mixed with unheated water to reduce the overall temperature( to ensure that the temperature of the circulating water leaving the station does not exceed 35°C for an ambient lake temperature of 28°C, which has a frequency of exceedence of less than 0.5%. A discharge temperature limit of 38°C is the current licence discharge limit for the existing power station. A greater water flow than 21 mVsec will be required when attemperation is being carried out.
Attemperation will be achieved by using additional pumps which will draw water from the intake canal and discharge it directly to the outfall canal to mix with the heated water discharged from the condensers. This system is similar to that employed at [raring Power Station.
Trash racks, screens and filters will be located at various positions in the circulating water system to protect the pumps and condensers from damage caused by floating debris, weed, shells and aquatic life and to minimise harm to or destruction of fish and other marine life. The combination of coarse racks, medium mesh screens and fine filters will remove all floating and buoyant material with a dimension larger than about 10 mm from the water before it can enter the pumps and condensers. Currently it is intended that filtered material will be sluiced to the outfall canal and returned to the lake. However investigations will be conducted on handling the filtered material in other ways, such as disposing of collected jellyfish, which are perceived as being over abundant.
3.6 DOMESTIC WATERSUPPLY
The proposed development will require approximately 1400 ML of fresh water annually when fully operational. The water will be used for boiler makeup and station domestic services and will be drawn from the local MWS&DB system, as is the case with the existing Tallawarra Power Station.
3.7 ASH COLLECTION PLANT
3.7.1 Fly Ash Collection Plant
The exhaust gases from the boiler furnaces will be cleaned to remove particulate matter before discharge to the atmosphere. The cleaning plant will be constructed with sufficient reserve margin to ensure that the requirements of the Clean Air Act can be met, even with sections of the plant out of service for maintenance. The fly ash collection plant will be subject to licencing approval by the State Pollution Control Commission. The Electricity Commission has successfully used fabric filters for exhaust gas cleaning at its Eraring, Bayswater, Tallawarra and Wang! Power Stations and it is expected they would be used for this project, unless a superior and more cost effective technology becomes available during the lead time to construction. I 3.7.2 Furnace Ash Collection I The furnace ash will be collected and quenched in a water filled hopper beneath the furnace, dewatered by either a submerged scraper conveyor or by a separate dewatering facility, and trucked to the ash storage area.
25 I I 3.8 CHIMNEY
A reinforced concrete chimney approximately 150 m tall, 17 m diameter at its base and 12 m I diameter at its top, will be constructed to disperse flue gases from the boilers and ensure acceptable ambient air quality at ground level.
Three methods were used in determining the chimney's height: a mathematical model, which I predicts gas dispersion over flat terrain: a field plume dispersion study, and wind tunnel modelling, both of which assess the effects of local topography on such dispersion. The height of the chimney and the exit velocity of the flue gas will be subject to approval by the I State Pollution Control Commission.
Although the chimney will intrude into the airspace for normal operation of Albion Park Aerodrome, as shown in Figure 3.8, the Department of Aviation has advised that the proposed I height of ISO m and location of the chimney are acceptable, provided that obstruction lights are installed and the chimney is painted in red and white horizontal bands. The details will I be the subject of further negotiations with the Department.
'. 3.9 ASH DISPOSAL
The total amount of furnace and fly ash resulting from the burning of each tonne of coal will be a maximum 0.44 m 3 of which approximately 90% will be fly ash and the remainder will be furnace ash. Fly ash will be extracted from the flue gas as indicated in Section 3.7 and furnace ash will be collected directly from a water filled hopper beneath the furnace. It is expected I that over the life of the station up to approximately 30 million ml of ash will be produced. Fly ash is used as a partial replacement for cement and is sold from Commission power stationsthrough contractors to various cement and concrete manufacturers. Since 1979, an annual average of 38,000 m3 of fly ash from Tallawarra Power Station has been sold, which represents 20% of the present average annual volume produced there. Fly ash which is not sold will be disposed of by conditioning with water to about 20% moisture content and then I placed as essentially "dry" land fill. I 3.9.1 Ash Storage Sites
Particular emphasis has been placed on examining ash storage sites which require a minimum ' of land acquisition for ash transportation and storage so that both the development cost and the impact on the environment will be minimised. I The main criteria used in the selection of the ash storage site(s) are:
a minimum total dry storage capacity of around 30 million m3; I • proximity to the power station. avoidance of environmentally sensitive areas; I • absence of any adjacent residential areas; preservation of any area or item of major Aboriginal or historical significance.
Both the capital and operating cost of any ash disposal system increase significantly with I distance from the power station.
Based on compliance with these criteria, two sites were identified from a number of alternatives as the preferred sites. The preferred sites are the existing ash storage area No. 3 I and an area adjacent to the station on power station property south of Mt Brown and east of the F6 Freeway. Storage details are given in Table 3.9.1. A detailed discussion of the I alternative ash storage sites which have been considered is contained in Appendix B. 26
i OBSTACLE LIMITATION SURFACE (TAKE OFFCLIMB) FOR ALBION PARK AERODROME NORTH-SOUTH RUNWAY -DERIVED FROM DEPT. OF AVIATIONS AIRPORT ENGINEERING INSTRUCTIONS
i 1r.INn
Power station structures TALLAWARRA POWER PROJECT below RL 52 fl Section of power station buildings Albion Park Aerodrome U above RL 52 Obstacle Limitation Surface Section of chimney above RL 52 FIGURE 3.8 I TABLE 3.9.1 I STORAGE FOR 30 MILLION m3 OF DRY PLACED ASH Selected Site Storage and Ash Type
No. 3 Ash Dam Mt Brown
15 million ml 15 million m3 Combined furnace Combined furnace I and fly ash and fly ash Years I to II Years 12 to 30
I These sites offer significant advantages in that: both on-site storages are adjacent to the power station and therefore, irrespective of the ash transport method adopted, considerable savings in capital and operating expendi- I ture will accrue due to their proximity; no major land purchase would be necessary;
3.9.2 Ash Transport
Fly ash will be collected from the fly ash collection plant and pneumatically conveyed in pipelines to the fly ash storage areas. I At the storage areas, the ash will be conditioned with water prior to placement. The quantity of water used will be sufficient to prevent fugitive dust emission but not sufficient to produce a water discharge problem. I Furnace ash will be transported by truck from the ash hopper or dewatering facility, as yet to be determined, to the ash storage area. I
3.9.3 Operation Principles of Proposed Ash Storage System No. 3 Ash Storage
Furnace and fly ash will be transported to the site as outlined earlier and spread and compactedby conventional earth moving equipment. The ash storage procedures will be coordinated to minimise the view of the workings within the storage area. A mound of ash will be built up generally along the southern wall and the visible faces rehabilitated immediately. ' This mound will be vegetated to screen future workings within the site.
Views from other directions can generally be obscured by additional tree plantings or are sufficiently distant to be unobtrusive.
Theultimate utilisation of the site will be the creation of a grassed and timbered hill to a maximum height of RL 60 m, approximately 58 m above ground level in the east and south and about 40 m above the hill to the west of the ash dam. Side slopes would be a maximum of aboutI in 3 and the material will be placed in an irregular manner so as to create a natural appearance.
The general disposal procedure will involve the subdivision of the area into blocks of about I to2 ha. Ash disposal will be carried out in one block at a time and the area would be progressively built block by block to its final height. External visible faces would be progressively topsoiled and vegetated.
No changes will be made to the existing drainage facilities around the No. 3 site.
28 I Drains and settling basins will prevent water being discharged from the site except under exceptional rainfall conditions. A perimeter embankment will be provided within the storage area to ensure that at all times, adequate storage is maintained from floods with a return period of less than 10 years. Larger floods will be discharged to the lake via the existing decanting pond skimmers, spillway and channels.
Dust will be controlled using water sprays and by keeping the exposed areas of ash to a minimum by promptly rehabilitating filled areas. Figure 3.9.3(a) shows the final contours I proposed for this site.
Mt Brown Site (Future No. 4 Ash Storage)
As indicated in Table 3.9.2, the additional storage area on the southern slopes of Mt Brown would not be required until at least II years after the first 660 MW generating unit is commissioned. Should the commercial uses of ash expand significantly or a more attractive disposal method than landfill be developed, there might be no requirement for the Mt Brown site or the extent of development curtailed.
Given the current timing of the project, the Mt Brown site may not be required for some 20 years from now ( I I years after operation of a 2 unit station) and only general arrangements of the proposed storage area have been worked out at this time. Figure 3.9.3(b) shows the outline arrangements envisaged for the Mt Brown Site.
3.9.4Restoration
Restoration of the visually exposed faces of the ash mound will commence soon after each lift in each outer worked area has been completed for the No. 3 ash dam case. A similar procedure I is envisaged for the Mount Brown development.
All placed ash will be covered with a layer of soil, fertilised, and planted with grass, trees and shrubs. Soil will be obtained from the Mt Brown disposal area.
Irrigation sprays will be installed and used to assist the establishment of the vegetation cover.
The Commission has already demonstrated the success of restoration procedures over ash deposits. Tallawarra No. I ash dam was filled in 1961 and subsequently rehabilitated in a similar manner to that proposed above. The area now supports trees up to 10 metres in height and a part of the area has been developed for sporting activities.
3.10 WATER MANAGEMENT
The site drainage and water treatment systems will be designed to treat run-off from storms with a return period of up to I in 10 years. Any discharges from water treatment systems will comply with the provisions of the Clean Waters Act. Both drainage and water treatment systems will be designed to maximise reuse of water. These design principles will minimise use of water supplied by the MWS&DB and reduce the possibility of accidental contami- nation of local streams and Lake Illawarra. Measures to be taken to prevent contaminated discharges to the lake and to conserve water include recirculation and treatment of water used for ash disposal and washing down purposes.
The various station water systems are shown schematically on Figure 310 and are discussed below, except for the drainage systems for the ash storage areas, which are discussed in section 3.9.3. I 3.10.1 Sewage Treatment
Sewage from all Construction and Generation staff will be treated and disposed of on site. it is proposed to use an intermittent extended aeration plant such as a P 1000 Pasveer Channel. Tertiary treatment will take place in maturation ponds with 14 days detention. Final disposal I 29 I I I PA I I I I I EXISTING I. I 61 I ft I Th \ \ \ III! H SETTLING ______30 / I 40 I POND 20 II. LEGEND —60— PROPOSED FINISHED SURFACE CONTOUR 1 (Level in metres) I DRAINAGE I TALLAWARRA POWER PROJECT No.3 Ash Storage I 200 aoOm Ultimate Development I FIGURE 3.9.3(a) I LEGEND —60— PROPOSED FINISHED SURFACE CONTOUR (Level in metres) DRAINAGE
0 200 400m
TALLAWARRA POWER PROJECT No.4 Ash Storage Possible Ultimate Development
FIGURE 3.9.3(b) MWS & DB FRESH WATER SUPPLY
1C H P WASHDOWN1 EXISTING L_.. SYSTEM j
OIL (RECLAMATION ) IL SOLI S /WATER O SEPA TOR LIDS ( III TO COAL (STORAGE)
C.H.P. DRAINAGE STATION N CONSTRUCTION STATION DEMINERALISED STATION L SERVICES & FIRE SUPPLY I DOMESTIC WATER-BOILER WASH DOWN S SUPPLY FEED WATER WATER AUX. COOLING SERVICE L WATER SUPPLY SOLIDS I STORAGE SYSTEM SYSTEM =D3ASIN:> I 1TO COAL CONSTRUCTION STORAGE DOMESTIC STATION WASH DOWN WATER SYSTEM SPI LLWAY (SINTTLING
SEWAGE TREATMENT CHEMICAL PROCESS DRAINS CONTAMINATED DRAINS UNCONTAMINATED DRAINS I PLANT INCLUDING REGENERATION DRAINAGE FROM AREAS DRAINAGE FROM ROOF DRAINS, WASTE FROM DEMIN. PLANT WITHIN THE STATION WHERE UNDISTURBED GROUND, AND CONDENSATE POLISHING CONTAMINATION IS LIKELY PAVED AREAS AND PUMP C.W. PLANT. DRAINAGE FROM BAITERY TO OCCUR FROM OIL, SOLIDS DRAINAGE FROM AREAS STATION SCREENS ROOM AND CHEMICAL DILUTION OR MINOR CHEMICAL WASTE. WHERE CONTAMINATION LAKE POLISHING PLANT AREAS, CHEMICAL EG. BOILER HOUSE, WORKSHOPS CANNOT OCCUR. rii PONDS STORAGE AREAS TURBINE HOUSE. * . C:) ... . H•.. ILLAWARRA
EMPTIO] [CREENED cO_ _ Ii N NDENSERJ TT LOCAL RIA I 1 NEUTRALISING CONTBAM ATED STATION I E I ______SPRAY I PLANT INCLU)IGN A CLEAN II IRRIGATIO_J (IF REQUIRED) I JR I DRAINS ASIINN E AS 1I I I LAKE WATER FRESH WATER OIL UNCONTAMINATED OIL/SO (TO RECLAMATION) DRAINAGE WAT AR ASHPLANT SOLIDS ING Li CONTAMINATED CONDIT (TO ASH STORAGE BASIN SKIMMER~M DRAINAGE ING AREA) C TAN CHEMICAL PROCESS CLEAN WATER DRAINAGE COLLECTION SCALE AND BASIN HING CORROSION E D CONTROL PLANT
EMERGENCY OIL SUPPLY, DUST FLY ASH IRRIGATION DUST CONTROL (TO RECLAMATIONI SYSTEM CONTROL AND HLG SYSTEM IRRIGATION PLANT ] WOLLINGURRY CREEK SPILLWAY FURNACE ASH FURNACE ASH ASH DRAINAGE FROW1 WATER STORAGE AREA ASH HANDLING HANDLING I MANAGEMENT ASH STORAGE AREA COLLECTION PLANT AREA J PLANT PLANT BASIN TALLAWARRA POWER PROJECT SOLIDS LING :BA IN WATER MANAGEMENT (TO ASH STORAGE PRINCIPLES 0 FIGURE 3.10 I by spray irrigation will occur in an area located to the north east of the existing station, adjacent to the existing sewage treatment works.
I 3.10.2 Construction Drainage
Construction drainage comprises run-off from areas disturbed during the construction period. I Drainage water will be directed to a settling basin where solids will settle out. Clean water ' overflow will go into Lake Illawarra or Wolligurry Creek. 3.10.3 Uncontaminated Drainage
Uncontaminated drainage comprises run-off from roof drains, lawns, paved areas etc. This will I be directed to the outfall canal via open channels or gravity pipework.
3.10.4 Contaminated Drainage
Contaminated drainage is drainage likely to contain solids or oil or chemicals from the hosing down of plant areas or from run-off from such areas.
I This will be directed to a collection basin, then to an oil/solids/water separator for treatment. The treated water will be stored in a clean water collection basin for re-use in the station washdown system or recycled to the ash conditioning water tank. The solids extracted from I the separator will be transported to the ash storage area, whilst the oil will be stored for removal by an oil reclamation contractor.
I 3.10.5 Chemical Plant Drainage
Chemical plant drainage comprises drainage from chemical processing plant and chemical I storage areas including demineralising plant, condensate polishing plant and battery room. This will be treated in a neutralising plant, if necessary, and then directed to the ash conditioning water tank.
I 3.10.6 Coal Handling Plant Drainage
Coal handling plant (CHP) drainage results from washdown practices and rainwater run-off from the CHP area.
Drainage from the coal plant washdown system is passed through an oil/solids/water ' separator. The separated oil is stored for the oil reclamation contractor, whilst the separated solids are returned to the coal storage area. The water from the separator is directed into the drain which runs along the perimeter of the coal storage area. This drain also collects rainwater run-off from the area. Water from the drain is initially collected in a primary I desilting basin from which the overflow goes into the main settling basin. Water from this latter basin is re-used in the coal plant washdown system. I 3.11 STORAGE AND USAGE OF HAZARDOUS SUBSTANCES
I Modern power stations use a number of substances requiring special handling which need to be stored on site. The functions and storages of such substances in the operation of the proposed development are outlined below.
I Oil
Oil is required for boiler furnace light up, flame stabilisation at low output, and for placing mills in service when loading the units. Oil storage capacity of approximately 2400 KL will be provided in two steel tanks in the location shown on Figure 3.1(c). The annual consumption is expected to be 7 million litres. Replenishment of the storage will require about five tanker trips per week.
33 I Hydrogen
Hydrogen is required for cooling the electrical generators. It will be produced on site by the electrolysis of demineralised water and then compressed to 14 MPa for storage in bottles having a total storage capacity of 2650 normal cubic metres. The expected annual usage is approximately 80000 normal cubic metres oran average 220 m 3 per day.
Chlorine
Chlorine may be required for the control of organic fouling in the closed circuit of the auxiliary cooling water (ACW) systems and will be required on the main CW system unless an alternative micro and macro fouling control system is employed. The normal daily consumption for the ACW system will be approximately 18 kg, and this will increase to approximately 200 kg/day if the main CW system requires chlorination. About 12 tonnes of liquid chlorine will be stored in 920 kg cylinders in a secure, open area.
Sulphuric Acid
Sulphuric acid will be used in the demineralised and condensate polishing plants which provide water for the boiler feed water system. The acid may also be required for the control of pH in the auxiliary cooling water system. Consumption of sulphuric acid (98%) is expected to be about 1.4 t per day. The total storage tank capacity required is approximately 130 t. Caustic Soda SI Caustic soda will also be used in demineralised and condensate polishing plants. Approximately I .6 t per day of 50% caustic soda solution will be required. A total storage capacity of approximately 145 t is proposed.
Anhydrous Ammonia
Ammonia will be used for boiler feedwater treatment. The normal daily requirement will be approximately 60 kg anhydrous ammonia which will be diluted to a 5% aqueous solution for I in(ection into the boiler feedwater.
Anhydrous ammonia will be stored in a 20 t capacity storage tank while the 5% solution will be stored in a number of stainless steel tanks. It will be delivered to site in IS t tanker loads. Hydrazine - Aqueous I Hydrazine will be used for treatment of the boiler feedwater. It will be supplied as a 35% aqueous solution in 200 L drums, delivered by truck. It will be diluted to approximately 0.5% for injection in to the feedwater. Consumption will be approximately 14 kg per day and the total storage capacity required is 1.2 t. 01 I 3.12 TRANSMISSION
The two 660 MW units will be connected to the Commission's transmission system via the existing Dapto Substation. A new double circuit 330 kV transmission line will need to be I constructed between the power station and the substation and each circuit of this line will connect a generator to the substation. The easement for this line is currently being investigated. The existing 132 kV line in the easement will be dismantled.
The dismantling of a portion of a second 132 kV line from Tallawarra to Moss Vale to clear the construction site will necessitate the construction of approximately 2 km of 132 kV line to terminate the line at Dapto Substation. Other transmission line works will include the rearrangement of existing 132 kV line connections to the Tallawarra 132 kV switchyard which will allow the majority of existing transmission line towers on the foreshore of the lake to be removed. I The connection of 1320 MW to the system at Dapto will require upgrading of the State grid by the construction of the Kemps Creek - Marulan 1500 kV) line a few years earlier than would be otherwise necessary.
34 I 3.13 TRANSPORTATION
I The project area adjoins the Princes Highway, the F6 Freeway and the South Coast Railway. Vehicular access to the power station site for south-bound vehicles is from the Princes Highway via the existing station access road. Vehicles can divert from the F6 Freeway at Dapto to the Highway. North-bound vehicles can leave the F6 to join the Highway close to the I station's access road. The F6 and related Highway access works near the station were recently constructed.
Based upon experience at other Commission power stations, it is estimated that there could I be up to about 1000 vehicle movements per day at the peak of construction activities at the power station. When the station becomes fully operational, the total number of vehicle I movements will be similar to existing traffic volumes. During the construction period heavy vehicles will tranport equipment and material to the site. The heaviest load to be transported will be the generator inner stator (approximately 300 tonnes) and this and some other heavy loads will be transported by rail and/or ship. They I will then be transferred to a road vehicle at the port or station for the remainder of the journey to the site.
I 3.14 LANDSCAPING
To improve the appearance of the project area and to enhance the appearance of the station I when viewed from the F6 Freeway, Lake Illawarra and the surrounding community, the site will be extensively lanscaped. The landscaping master plan is shown in Figure 3.14.
Areas of the site not occupied by the station works will be managed to control weeds, pests I and soil erosion.
It is proposed to commence early major landscaping works, such as tree planting, mounding I and revegetation, so as to maximise the degree of screening during construction. Existing native vegetation will be retained wherever possible. These works will be integrated with rehabilitation works previously carried out on ash dam No. I and the planting associated with the recent development of the No. 3 ash dam. Rehabilitation of the No. 2 ash dam area is I currently being carried out.
I 3.15 CONSTRUCTION ' 3.15.1 Construction Programme
On present projections of load growth and on the assumption that the Tallawarra redevelopment will follow Mt Piper Units I and 2, the new station is predicted to be required for commercial operation in 1995 at the earliest. The project programme is shown on Figure I 3.15.1; however, no firm commissioning date is indicated, as it will be reviewed having regard for actual load growth, conservation and co-generation programmes, the performance of other power stations and the relative costs of other forms of generation.
The first work to be carried out at the site will be landscaping activities, followed by the main earthmoving activity, relocation of the existing ash slurry pipeline, the creation of a temporary coal storage area, and the dismantling and relocation of some transmission lines. I The only construction activities away from the power station area will be the works associated with the coal transport system and transmission works.
I 3.15.2 Construction Materials
The main materials (in terms of quantity and weight) that will be transported to the site for I the construction of the station are cement (40 000 t), sand (120 000 t), concrete aggregates ( 130 000 t( and structural and reinforcing steel (50 000 t(. The sources of these materials and method of transportation will be decided by the contractors selected to supply them. There I are a number of igneous rock quarries in the region from which coarse aggregates could be
35 I taken. Sand could be extracted from Kemblawarra or Gerroa, while cement is expected to come from Berrima. The bulk of the steel work is expected to be fabricated in Wollongong or Sydney.
3.15.3 Construction Works Facilities
Space is required for the contractors' offices, amenities, carpark and workshops, for storage of equipment, stores and materials, as well as for the assembly of large plant items.
Temporary facilities are also required for Commission site staff offices, materials testing laboratories, stores, workshops and garage facilities.
The main construction facilities are shown on Figure 3.1 (e).
3.15.4 EmploymentOpportunity
A construction workforce of up to approximately 1400 persons will be required. A table showing the variation of construction workforce over the duration of the project is set out below. The median workforce for each six months is shown.
Year relative to 1St Unit -4 -3 -2 - I 0 + I operation
Median Workforce 60 150 250 350 450 650 950 1250 1400 1250 800 300 50 Numbers
It is expected that a significant proportion of the workforce will be drawn from the surrounding community.
3.16 APPRENTICE TRAINING
As with past power station developments, the Commission will make a commitment to apprentice training. It is envisaged that existing apprentice training facilities at Tallawarra Power Station and at the Port Kembla Regional Centre will be utilised for apprentices employed as a result of the Tallawarra project.
3.17 LAND REQUIREMENTS
The project will be constructed on land currently owned by the Electricity Commission of I New South Wales or Huntley Colliery Pty Ltd (a wholly owned subsidiary of the Commission), apart from the lands required for the coal transport system between the colliery and the power station, the possible rail facility, and small areas adjacent to the proposed Mt Brown ash storage site and No. 3 Ash Storage area. The exact land needed to be acquired is yet to be determined. Figure 3.17 illustrates the existing property boundaries.
The land required for the coal transport corridor will not be determined until the results of the coal pipelining investigations are completed. I I Pu 36 I ..- ie
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41
TALLAWARRA POWER PROJECT Landscape Master Plan LEGEND EXISTING VEGETATION FIGURE 3.14 PROPOSED VEGETATION _____
I YEARS FROM INITIAL OPERATION OF FIRST OPERATING UNIT -7 -6 -5 -4 -3 -2 -1 0 A A A A I FIRST UNIT SECOND UNIT DEVELOPMENT AWARD MAIN KEVACTIVITIES INITIAL INITIAL CONSENT PLANT CONTRACT OPERATION OPERATION I ENVIRONMENTAL IMPACT STATEMENT PREPARATION I
ASSESSMENTAND I DEVELOPMENT CONSENT
DETAILED ENGINEERING STUDIES U • U • U • U • I I COAL HANDLING
ASH DISPOSAL
.CIRCULATING WATER
WATER MANAGEMENT
INSTRUMENTATION
I DESIGN PARAMETERS
CIVIL WORKS I PRELIMINARY WORKS • • •
ACCESS ROAD
TEMPORARY COAL STORAGE
RELOCATION OF ASH PIPELINE
TRANSMISSION LINE REROUTING AND DISMANTLING
ANALYSE MAIN PLANT TENDERS U
SITE PREPARATION WORKS U U
MAIN PLANT CIVIL WORKS IU U U U I U U U U • • U • I BOILER ERECTION I TALLAWARRA POWER PROJECT Proposed Project Programme
FIGURE 3.15.1 I I I I I-
1 I
Li
SI
I I
TALLAWARRA POWER PROJECT I Existing I #'rRIr Property Boundaries Electricity Commission Land I fl Huntley Colliery Land FIGURE 3.17 Li I
I 4. EXISTING ENVIRONMENT
4.1 THE COMMUNITY
Pertinent information on the existing community which can be affected by the proposal is set out in the sub-sections 4.1.1 to 4.1.8. The information is substantially drawn from a I consultant's community impact study.
I 4.1.1 Planning Instruments The power station site and all its associated works are located wholly within the City of Wollongong. The relevant environmental planning instruments for the area are the Illawarra I Regional Environmental Plan (REP) No. I, Wollongong Local Environmental Plan (LEP) No. 38 and State Environmental Planning Policy (SEPP) No. 14 "Coastal Wetlands". Wollongong Council's zonings for the general and immediate areas around the site are shown in Figure I 4.1.1, Under Wollongong LEP No. 38 the main station area, including coal handling facilities, is located in an area zoned "Special Uses Power Station", as shown in Figure 4.!.!. A portion of the ash storage site at Mt Brown is zoned "Private Recreation", while No. 3 ash dam falls in an area designated "land with landscape or environmental attributes" in the Illawarra REP No.!.
The coal transport corridor and rail loop are located on areas variously zoned Rural 1(a), Rural 1(b) and Offensive and Hazardous industries 4(d). The coal transport system is recognised in the Illawarra REP by the inclusion of a service corridor between Huntley and the power station on the "Service Corridors" map. Much of the transport route falls in an area recognised I in the REP as land potentially suitable for urban use. The Commission property south of Wallingurry Creek and east of No. 3 ash dam is zoned "Conservation Wetland" under LEP No. 38 and some of the area is also recognised as I Wetlands under SEPP No. 14. No development is proposed on these wetlands. I 4.1.2 Population Population numbers, as recorded in the 1981 census by the Australian Bureau of Statistics, for the main population centres within 10 km of the Tallawarra site are as follows:
Population Centre Population
Dapto 22 857 Berkeley 4 935 I Lake Heights, Warrawong 9 658 Primbee, Windang 3 920 Unanderra I! 229 I Shellharbour 4! 790 94 389
The total population of the Wollongong sub-region which takes in the local government areas of Wollongong, Shellharbour and Kiama is approximately 223 000.
4.1.3 Regional Economy and Employment
Wollongong Sub-region
The Region's industries have been subject to marked technological change, especially in the iron and steel industries and coal mining, the latter due to the introduction of long wall mining.
Approximately three quarters of employment in the Illawarra Region is based in the Wollongong coastal plain, which is the area of focus of the community impact study. The Statistical Division of Illawarra and South-Eastern, which encompasses the lllawarra Region,
42 I had an unemployment rate of 11.6% in August 1986 which is well above the Sydney rate of 6.8% for November 1986. Since the mid 1970's, the Region has had unemployment levels exceeding the national average. Between 1980/81 and 1982/83 employment in manufacturing establishments in the Illawarra Statistical Division fell by 17%.
Registration figures from CES offices in Dapto, Wollongong and Warilla indicate the proportion of male and female unemployed is fairly consistent at 60% male to 40% female. The highest grouping with regard to occupational type is Clerical/Sales Workers (41%), followed by Manufacturing and Construction (22%), and Basic Manual Labour(l8%).
Tallawarra Power Station and Huntley Colliery
The power station employed 363 personnel as at April 1986, with a workforce structure, as shown in Table 4.1.3(a). Additionally, five coal haulier drivers and three persons engaged in I lagging and fly ash activities are employed by contractors to the Commission at the station
TABLE 4.1.3(a)
TALLAWARRA POWER STATION
Professional 14 Operating 66 Supervisory & Subprofessional 47 Technicians and Tradesmen 72 Clerical 16 Non Trades 146
TOTAL 363
It is estimated that 25 to 30% of the total workforce are unskilled. Apart from wages, which amount to approximately $200,000* per week or $IOM* per annum, the station also spends between $6M * and $7M * per annum locally on stores and services, including timber supplies, CIG gases, oil for "start-up" motors, rewinding of motors, machining of parts, galvanising plumbing, and any urgent items.
In a regional context, employment, wages and salaries at the power station represent approximately 1% of the Illawarra Statistical Division's 1984/85 employment, wages and I salaries paid in manufacturing establishments, of which almost 90% is concentrated within the City of Wollongong.
The Huntley Colliery, which employed 370 people, as at May 1986 had the employment structure shown below. I TABLE 4.1.3(b)
HUNTLEY COLLIERY I
Professional/Administrative/Clerical 80 Tradesmen 166 Mineworkers 113 Trainees II Total 370 I The 113 mineworkers represented some 3% of the total mineworkers and quarrymen employed in the Illawarra Statistical Division, as shown in the 1981 Census.
Average annual earnings were $30,000* per annum, with the total wages bill being about $1 I M *• Local outgoings at the mine for operating costs totalled around $4M * in 1984/85.
* 1984/85 figures. I I I / I I I I A ':
I 8 9 / / -O •- - / . •' ' - - I 00000 .1 - . -, - a, I 4 - / :- -•--
11W 71
I - -- LEGEND
All 1 RURAL 6 OPEN SPACE
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I Wollongong Local Environmental Plan No. 38 Reproduced with the permission of TALLAWARRA POWER PROJECT Wollongong City Council I Land Zoning FIGURE 4.1.1 I I I 4.1.4 Commercial and Industrial Facilities I The economic structure of the Wollongong sub-region is dominated by the iron, steel, metal fabrication and coal industries. Other activities such as transport, warehousing, retailing and service industries are essentially ancillary to the main industries listed above. This structure has the effect of making the economy of the region highly subject to fluctuations in the I national economy and export markets. I 4.1.5 Accommodation
I The housing market in general appears to be volatile. The number of commencements/ completions in the Illawarra Region for new housing has ranged between 1000-1800 per annum for houses and 200-1100 per annum for flats in recent years. However, there is I sufficient land stock in the region to potentially last until early next century, even with a high population growth rate. Cost considerations indicate that the most logical sequence of expansion would commence in the West Dapto and Albiori Park areas. I Temporary accommodation in Wollongong is limited, particularly for longer term accommo- dation. There are probably less than 200 rooms in guest or boarding houses and the number of permanent beds in hotels is declining. Although the caravan parks in the region have a I total capacity exceeding 3,000 persons with low average occupancies, peak seasonal demands limit their availability for long term accommodation. Summer holiday periods also restrict the availability of motel rooms for workers, although the cost of this type of accommodation I would probably make them unattractive. The present power station and colliery workforces reside over a wide area, the boundaries of which approximate a commuting time of three quarters of an hour. It is estimated that only about 25% of Tallawarra Power Station employees live at Dapto, with 15% in the Shellharbour I area and the remaining 60% residing at Kiama, Gerringong, Bulli, Thirroul and Wollongong. The place of residence of Huntley Colliery employees is currently as follows: I Wollongong North 20 Central 10 I South 35 Shellharbour 30 I Kiama and South 5 I I 4.1.6 Community Support Facilities Community support facilities and services in the vicinity of Tallawarra Power Station are for the most part provided by Wollongong City Council, Shellharbour Municipal Council, I Department of Youth and Community Services and Department of Education. They include the following:
Preschools/Kindergartens 18 I Long-day Care Centres 5 Neighbourhood Centres 6 Libraries 7 I Public Hospitals 2 Baby Health Centres 5 Community Health Support I Centres 4 45
I 4.1.7 Water Supply
Water supply to the Wollongong sub-region is provided by the Metropolitan Water Sewerage & Drainage Board and is considered adequate for all expected developments to the turn of I the century.
4.1.8 Transport Facilities I
Public transport facilities for commuters are very limited and most travel within the region is by private vehicle. The F6 Freeway services the Wollongong sub-region and provides good access to the Dapto area.
The South Coast railway, which has been recently electrified from Helensburgh to Wollongong, also provides good access to the sub-region and the Dapto area in particular. Port facilities are available at Port Kembla.
Albion Park Aerodrome is located approximately 4 km south-south-west of the power station. It is used principally for flight school and training operations, as well as commuter air services with limited capacity passenger flights. In 1982 approximately 5000 aircraft movements occurred through the airport.
4.2 PHYSICAL ENVIRONMENT
4.2.1 Topography, Geology and Soils
Tallawarra Power Station is situated in the Illawarra Basin on the western shore of Lake Illawarra, immediately east of Mt Brown which is a prominent hill rising to about 130 m above lake level. The Illawarra Basin is bounded on the western side by the Illawarra escarpment which lies approximately 9 km from the power station at its nearest point and rises to elevations of between 500 m and 600 m above sea level. The Basin covers an area of approximately 250 km2 and the terrain is generally undulating in nature. The major part of the existing station area has been cut into the lower slopes of Mt Brown.
A broad alluvium and slopewash filled valley originates on the middle slopes of Mt Brown and trends in a south-easterly direction through the northern part of the existing coal handling plant and into an alluvial plain area covering the shores of Lake Illawarra. Thick alluvial and estuarine sediments lie beneath fill material on the lakeshore adjacent to the power station and in the flat area, south and east of the coal handling plant, which is largely covered by power station ash deposits.
Most of the area immediately west of Lake Illawarra is underlain by Budgong Sandstone which is the uppermost unit in the Shoalhaven group. Weathered and fresh Budgong Sandstone is I exposed in the rock batters in the power station and coal storage areas. Mt Brown is capped by the Dapto Latite Member which is the uppermost latite body in the Shoalhaven group. I 4.2.2 Land Use
The land required for the project comprises the existing power station site, a coal transport corridor to 1-luntley Colliery, strips of land on Mt Brown and near No. 3 Ash Storage Area, and possibly a rail loop adjacent to Dapto Substation.
The coal transport corridor and rail loop areas have been largely cleared and are principally I used for grazing.
A veterinary hospital is situated adjacent to the coal transport corridor, to its south near Marshall Mount Road. A TAFE College is currently being erected near and to the north of the coal transport corridor, near Marshall Mount Road.
Except for some areas leased for grazing, the power station site is used solely for power station purposes, including coal and ash storage. An aerial view of the site is presented in Figure 4.2.2. I 46
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TALLAWARRA POWER PROJECT Aerial Presentation of Site
FIGURE 4.2.2. VOW
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TALLAWARRA POWER PROJECT Aerial Presentation of Site FIGURE 4.2.2.
4.2.3 Climate
The Commission has been collecting wind records at Tallawarra Power Station sihce 1963, and operating a climatic station at the site since 1972. Figure 4.2.3(a) illustrates pertinent meteorological data for the period 1972 - 1983 and Figure 4.2.3(b) shows the wind characteristics for the period 1976 - 1985.
Rainfall(1972 to 1983)
Annual average rainfall 1082mm Average number of rain days per year 73mm Maximum recorded daily rainfall 244mm Maximum recorded three day rainfall 436mm
Dry Bulb Temperatures (1972 to 1983)
Maximum recorded 43°C Minimum recorded 1°C Wind Recorded 12 m Above Ground Level (1976 to 1985)
The wind direction is mainly from the south-westerly quarter with calms persisting for an average of 12% of the time.
Seasonal wind roses are summarised as follows:
Sprirg - Dominance of southerly to westerly; 8% calms.
Summer - Dominance of north-east to east and south to southwest; II % calms.
Autumn - Dominance of south-west to west; 13% calms.
Winter - Dominance of south-west to west; 15% calms.
4.2.4 Flooding
Lake lilawarra has an area of approximately 35 km2, with a maximum depth of 3.5 m, and an average depth of approximately 2 m.
The entrance to the lake from the Pacific Ocean is situated near Windang. It has been closed to tidal inflow on numerous occasions in the past due to the build-up of shoals. The entrance is reopened either as a result of overtopping during flooding or artificial excavation.
When the channel is open the lake is generally only slightly tidal with a maximum range of about 50 mm. The average level of the lake is about 300 mm above mean sea level i.e., RL 0.3 m. This level can fluctuate with a variety of conditions including sustained wind direction, entrance conditions, drought and floods.
Numerous floods have been recorded in Lake lilawarra, the levels of which are principally affected by rainfall in the catchment and prevailing conditions at the lake entrance.
The flood of February, 1984 produced a general level of RL 1.9 m in the lake, with a level of RL 2.0 m recorded near the mouths of Macquarie Rivulet and Mullet Creek. This was the highest flood level ever recorded in Lake Illawarra.
The Public Works Department and other authorites have adopted a level of RL 2.0 m A.H.D. which approximates to a I : 100 year flood event. In such an event, a significant area south- west of the power station and adjacent to No. 3 ash storage area would be inundated as shown in Figure 4.2.4.
The flood levels of Duck Creek and its tributaries to the west of the power station have also been studied, as the coal haul route will cross the Creek at two locations. Backwater curves have been calculated for a I : 100 year rainfall event, assuming that a flood level of RL 2.0 m would exist in the lake. These curves are also shown in Figure 4.2.4 and indicate that the Marshall Mount Road bridge would be overtopped by 1.3 m in such an event.
48
I 240 220 200 Mean Rainfall I 180 E 160 I - 140 U- 120 C 10 100 a) .0 I 8 80 E 60 6z I 40 4 > a 20 2 0 .0 I J FMAMJJASOND Month RAIN FALL -TALLAWARRA CLIMATIC STATION I. 1972 -1985 30 50 I 25 40 = ci) 20 I- I D = 30 15 0 a) Mean Daily Minimum I a. E u 20 10 I CT
I. 0 JFMAMJJASOND 012345678 I MONTH Octas TEMPERATURE - TALLAWARRA CLIMATIC STATION TOTAL CLOUD COVER - NOWRA 1972-1985 1983 I Source: Bureau of Meteorology I TALLAWARRA POWER PROJECT Meteorological Data
I FIGURE 4.2.3(a) IjI PEAK 50 PEAK 50 N N 35 Km/h 43Km/h 40 40 50 PEAK 50 PEAK NE 4Q NE 30 40 32 Km/h 30 40 Km/h PEAK PEAK 30 30 NW 20 NW 20 69 Km/h 20 62 Km/h 20 SQ 50 10 10 10 10 40 40 30 30 10 20 10 20 20 20 20 10 20 10 10 20 10 20 30 40 50 10 10 20 10 20 30 40 50 lo
1EAK 20 CALMS (LESS THAN 10 20 CALMS —(LESSTHAN 10 E - PEAK 2 km/h) OCCURRED 49 Km/h PEAK 2 km/hI OCCURRED E PEAK 10 FOR 10% OF TIME 20 41 Km/h W 10 FOR 12% OF TIME 20 W 62 Km/h 52 Km/h 10 50 40 30 20 10 10 10 50 40 30 20 10 20 10 20 20 20 10 20 20 10 2010 30 20 10 30 40 40 10 10 \ 10 PEAK 50 PEAK 10 PEAK 50 PEAK SE 20 SE SW 20 59 Km/h SW 20 48 Km/h 48 Km/h 20 40 Km/h 30 30 40 30 50 40 PEAK PEAK S 36 Km/h 150 46 Km/h 50
SPRING
P EAK PEAK G( 50 N N 33 Km/h 49 Km/h 40 40 50 PEAK 50 PEAK E 40 NE 30 40 33 Km/h 30 20 Km/h 30 PEAK 30 20 NW 20 20 69 Km/h 20 50 10 10 50 10 10 40 30 10 20 10 20 20 10 20 20 10 10 20 30 40 50 10 20 10 20 30 40 50 10 10 20
0 CALMS—ILESSTHAN 10 PEAK 20 CALMS—(LESSTHAN 10 PEAK E PEAK 2km/h) OCCURRED E PE 2km/hI OCCURRED 43 Km/h 0 FOR 15% OF TIME 20 43 Km/h W 10 FOR 12% OF TIME 20 W 72Km/h 69 * 50 40 20 10 10 SQ 40 30 20 10 20 10 10 20 20 10 20 20 20 10 30 20 10 30 40 2040 10 10 PEAK 50 PEAK 10 10 50 SE PEAK S 20 SW 20 SE 591h 20 59Km/h 27 Km/h 20 43 Km/h 0 30 50 40 PEAK PEAK 5 50 33 Km/h 46 Km/h
AUTUMN WINTER
PEAK N 49Km/h 40 PEAK NE NOTE 30 40 40 Km/h PEAK 30 WIND DATA FROM ANEMOMETER LOCATED 12 M NW 20 81 Km/h 20 ABOVE GROUND LEVEL AT TALLAWARRA POWER 50 10 10 STATION. 40 SCALE ON OCTAGON AXES IS PERCENTAGE OF 30 10 20 TIME. 20 20 10 20 10 10 20 10 30 40 50
20 CALMS - ILESS THAN 10 PEAK 2km/hI OCCURRED E PEAK FOR 12% OF TIME 20 49Km/h W 10 72 Km/h 50 40 30 20 10 20 10 10 10 20 20 20 10 30 TALLAWARRA POWER PROJECT 40 10 PEAK 50 PEAK 10 SE SW 20 50 Km/h 59Km/h 20 Wind Roses 30 40 30 50 40 PEAK S 46 Km/h 50 FIGURE 4.2.3(b)
ANNUAL . • Mount Bn
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EXTENT OF I BACKWATER 19 CALCULATION S LEGEND No.3 ASH STORAGE 23 — 20 17 1 in 100 YEAR WATER SURFACE LEVEL (A.H.D.—METRES) ( AREA I 21
TALLAWARRA POWER PROJECT Duck Creek Estimated I in 100 Year Flood Inundation FIGURE 4.2.4 4.2.5 Archaeology
Archaeological surveys for the Tallawarra Extensions were carried out between September I 1984 and September 1986 by a qualified archaeologist, in consultation with the Illawarra Aboriginal Land Council. Surveys have also been undertaken in the past for nearby transmission line projects and on the No. 3 ash storage area. The power station site was not I formally surveyed by an archaeologist for Aboriginal relics since it is already heavily developed for power generation. Figure 4.2.5 shows the area covered by archaeological surveys undertaken by or for the Electricity Commission. I The areas considered most likely to contain archaeological sites are relatively undisturbed areas, that is dry sclerophyll forests, the lake shores and the banks of Duck Creek and its major tributaries. However, even these areas have been substantially disturbed by European I settlement. Clearing, creek widening, pasture improvement for agriculture, heavy vehicle movement and road construction have reduced the likelihood of finding undisturbed Aboriginal sites in the survey areas. Thick grass cover and patches of blackberries and lantana further hamper survey work. I Eight Aboriginal relics were found during the Tallawarra Project Survey, all of which are in the coal transport corridor survey area. They consisted of five isolated finds and three open sites, one of which was associated with two scarred trees. The surveys associated with earlier I transmission works recorded several sites including a camp site, scarred trees and two middens, while the survey of the ash dam concluded that there was no evidence of archaeological sites of importance within that area.
I The emerging picture of Aboriginal occupation and site distribution in the Illawarra region would suggest that, despite the problems of locating relics, the low number of sites found probably relates to low usage of the area between the escarpment and Lake Illawarra by I Aborigines.
4.2.6 Flora and Fauna
A flora and fauna study of the area was carried out by suitably qualified personnel from the University of Wollongong. Their findings are discussed below.
The survey area has been extensively cleared for agriculture and power station development, with only patches of native vegetation remaining. These can be grouped into four broad categories,namely, residual forest, tree covered pastures, wetland communities and lake foreshores. Their distribution is shown in Figure 4.2.6.
The area around South Avondale Road (Area I on Figure 4.2.6) consists of a woodland community dominated by Eucalyptus tere(icornis on the ridges and drier slopes, with dry I subtropical rainforest in the gullies and on the more protected slopes. A total of 90 rainforest species were recorded in this area including specimens of Auslromyrlus acmenoicles which is considered to be rare in southern New South Wales. A number of other rainforest plant I species of some conservation significance were also identified. This area was originally included in the survey as part of investigations into areas suitable for ash storage.
The residual forest to the north and north-west of Dapto Substation is fragmented by I easement clearings into discontinuous portions shown collectively as Area 3 on Figure 4.2.6. The low lying, poorly drained ground supports a low paperbark forest giving way to stringybarks on the better drained slopes. The only evidence of native mammal habitation I was in the form of abandoned platypus and waterrat burrows along the creek. Birds typical of open paddocks and vegetated stream banks were recorded. These areas have been subjected to a substantial degree of disturbance associated with grazing, rail construction and power easement clearing and are too small to be considered to be of scientific value, although they I do have moderate value as bird habitats. The forest west of Marshall Mount Road, which occupies part of the property "Logbridge Farm" and adjoining properties (Area 2 in Figure 4.2.6) is one of only three sizeable natural I sclerophyll forest habitats west of Lake Illawarra. It consists of a low, discontinuous prickly shrub strata, approximately I m high, a scattered taller shrub strata to 3 m and a sparse but I continuous tree canopy at about 20 rn. An herbaceous ground cover is present throughout the
52 Reproduced by permission of the Director, . .... Central Mapping Authority of NSW. " .
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TALLAWARRA POWER PROJECT I Areas Surveyed for Archaeological Study Li I r?'IIIr FIGURE 4.2.5 Survey Area I /
Reproduced by permission of the Director, I Central Mapping Authority of NSW. I I
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TALLAWARRA POWER PROJECT I 1 rr.r-Rin Study Area Areas Surveyed for Residual Forest Flora and Fauna Study Tree Covered Pastures I Wetland Communities Lake Foreshores FIGURE 4.2.6 I I Area referred to in text I I forest except where some large patches of mosses and lichens occur. The tree canopy is dominated by eucalypts, with paperbarks occurring in the low lying areas.
During the survey a few isolated rosettes of Pterostylis sp. leaves were observed. This is a genus of orchids which contains the rare and endangered species Pterosty!is gibbosa. The orchids did not flower during the survey period (June to November, 1984) and a species verification was not possible. However, the "Logbridge Forest" is almost identical to the "Yallah Bush" habitat immediately to the south of the survey area, where P. gibbosa has been positively identified. There is therefore a distinct possibility that the orchid grows in "Logbridge Forest". I Only a limited number of native mammal species were recorded, none of which are rare or endangered. These include possums, bats and sugar gliders. One echidna was sighted.
Area 2 is however important for native bird life. It serves as a habitat for migratory and resident species with many species nesting there. The consultant recommends that this forest should not be further disturbed.
Other residual forest areas are generally too small and too scattered to be ecologically significant. The wetland communities can be grouped into four categories: I Casuarina Woodland a woodland dominated by Casuarina glauca (Swamp Oak) and occurs on the moister flood plain soils adjacent to Lake Illawarra and nearby streams.
Mela!euca Closed Shrub a densely growing community of Melaleuca ericifolia (Swamp Paperbark) with no tree sized plants and little undergrowth. This occurs in low-lying freshwater sites on usually moist flood plain soils and is associated with the Casuarina woodland.
juncus Rush Swamp - a swamp dominated by water plants, particularly the species Juncus kraussii. The community is about one metre tall and covers soils which are water-logged for much of the time.
Fresh wetlands - this system contains water plants associated with fresh water environments where the water table is above ground for most of the time. The vegetation is varied and includes many species.
Those wetland areas south and east of Wollingurry Creek, shown collectively as Area 4, Figure 4.2.6, are considered to be of regional ecological significance, as much of the estuarine vegetation around the lake has been removed. They form habitats for a variety of water birds and waders. Latham's Snipe was recorded in the area during the study. This bird has been included on the list of Fauna of Special Concern (Schedule 2, National Parks and Wildlife Service Act, amended 1984). 01 The lake foreshores contain rock platforms, mud/sand flats, salt water shallows and beaches as well as a few small patches of salt marsh with exotic herbaceous plants covering the adjacent ground. These areas are of minor habitat value for water birds and waders due to their very narrow extent. 4.2.7 Heritage
Wollongong Local Environmental Plan No. 38 includes Schedule I entitled "Items of the Environmental Heritage". The schedule identifies the following items in the vicinity of the proposed works: Avondale, off Avondale Road, West Dapto Penrose, off the Princes Highway, Dapto.
The Illawarra Regional Environmental Plan No. I includes Schedule 4 entitled "Items of Environmental Heritage" which identifies Yallah Bush, near Marshall Mount Road and Yallah which is in the vicinity of the proposed works.
A late 19th century pole frame, slab wall settlers' cottage known as either Lin brook" or I "Glenora" is situated to the south of the conveyor route. It is not listed as a heritage item in either of the above plans.
55
I None of the heritage items Listed above nor the settler's cottage is located within the boundaries of the project works.
I 4.2.8 Water Quality of Lake Illawarra
The Electricity Commission monitored the water of Lake Illawarra at eight locations, as shown I in Figure 4.2.8, on a monthly basis from July, 1981 to June, 1983. The parameters monitored were salinity, temperature, dissolved oxygen, pH, nitrate (plus nitrite), phosphate, silicate and secchi depth. Lake salinity was also measured by the Commission between January 1957 and January 1964, while lake water temperature has been measured continuously by the I Commission at the Tallawarra Power Station Cooling Water Inlet since February 1980. In addition various lake water quality measurements have been carried out by Wollongong City Council (1976), Lake Illawarra Management Committee (1985), the State Pollution Control I Commission (1986) and the University of Wollongong (1977). Unless otherwise stated, the results presented in this section are derived from the Electricity Commission's 1981-1983 I survey.
I Lake Heights I. 1 Primbee Purrafl Bay
I 3
04 I TALL.AWARRA POWER STATION Lake 006 Illawarra I 05
07 1 Windang I. I Creole Pt. Oak FIats 0 I 2kms
I LOCATION OF WATER MONITORING STATIONS Figure 4.2.8
I (a) Salinity Salinity in Lake Illawarra is influenced by inflows of fresh water from tributaries, tidal I exchange with coastal water, rainfall and the rate of evaporation. The maximum, minimum and average salinities were 41.1, 20.5 and 33.0 parts per thousand, respectively. Hypersaline conditions due to drought existed in September, 1981 and from July 1982 to March, 1983. There was no difference in salinity between locations or between surface and bottom water at all times and at all stations except at location I, which is situated in shallow I water at the mouth of a creek. The lack of difference indicated that the lake was well mixed. Mixing was most likely caused by wind stirring, as the lake is exposed to onshore seabreezes and southerlies.
The maximum and minimum salinities recorded by the Electricity Commission and Wollongong University during various periods between 1957 and 1983, were 42.5 and 8.7 parts per thousand, respectively.
Temperature
The variations in water temperature in Lake Illawarra are summarised below:
Maximum recorded temperature: 36.6°C Minimum recorded temperature: 7.3°C Mean of recorded temperatures: 20.0°C.
The maximum temperature was observed at location 7, which is located 200 m from the end of the power station outlet training wall. The minimum was measured at location I during winter. Although the surface temperatures at location 7 were always higher than those at other stations, the bottom temperatures at location 7 were not significantly different from the other locations. Also, the profile average temperature was not significantly different from the other stations.
Measurements of temperatures have shown that the heated water discharges from Tallawarra Power Station are generally confined to an area of about I km2 near the end of the outfall canal and limited to a temperature rise of 2°C above the ambient Lake temperature.
Continuous temperature records at the inlet to the existing Tallawarra Power Station give representative temperatures of the natural temperatures of the lake. These records show I that the natural lake temperature, as distinct from outlet temperatures, can reach a maximum of 30°C. However, this temperature would only persist for a few hours and for design purposes the normal summer maximum temperature can be taken as 28.0°C I which is exceeded less than 0.5% of the time. This has been taken as the maximum temperature for the design of the circulating water system.
Dissolved Oxygen
The dissolved oxygen (DO.) was measured as concentration (mg/L). These concentra- tions can be converted to percent saturation values. I Water at a given temperature and salinity has an equilibrium value of dissolved oxygen when in contact with air. This is the 100% D.O. concentration or saturation value. If oxygen is introduced to or depleted from the water through another mechanism, such as 01 photosynthesis, the water may contain more or less oxygen than the saturation value. The percent saturation value is a measure of oxygen enrichment or depletion of water.
The maximum D.O. concentration and percent saturation values were 10.9 mg/L and I 158%, respectively, for surface water recorded at location I in October, 1982. The corresponding minima were 4.9 mg/L and 74% for surface water in January, 1982, also at location I.
The D.O. concentration at location 7 near the power station outfall averaged 0.4 mg/L lower than the average of all locations of 7.8 mg/L. At this location, the average percent saturation of 110% was 4% higher than the average saturation levels of the other stations.
The suggested reasons for these differences follow.
The solubility of oxygen is dependent upon water temperature. Hence the observed decrease of D.O. concentration in the power station outfall area is due to increased water temperatures. However, the high percent saturation measured in this area, compared with others, shows that the loss of oxygen from solution was less than expected from the rise of water temperature. This is due to the slow rate of diffusion of oxygen from solution compared with the rapid temperature rise of water passed through the power station cooling water system. I 57 I I As can be seen from the average percent saturations the lake was generally supersaturated with oxygen. This was most likely due to oxygen production during the day by photosynthesis of over abundant phytoplankton which, in turn, is caused by an I excess of the nutrient phosphorus. I (d( pH U The maximum and minimum pH values were recorded in December, 1982 and were 8.8 at location I and 7.3 at locations 2, 4 and 6, respectively. The average pH was 7.7, which is I similar to the average pH of 8.2 for Lake Macquarie and 7.9 for the Tuggerah lakes. (e( Nitrate (plus Nitrite)
Phytoplankton cells contain nitrogen and phosphorus. After bacterial degradation of the I cells, these elements are released into the water column. The nitrogen is released in the form of ammonia, which is oxidised to nitrite and then nitrate by nitrifying bacteria in the water column. I The average surface nitrate plus nitrite (measured as nitrate( concentration during the survey period was 7 mg/ L, which was an order of magnitude less than the average surface phosphate concentration of 55 mg/L. These results indicate significantly lower than I expected nitrate concentrations. The cause of these unexpected results is yet to be • determined. The nitrate concentrations have been low for a long time. Measurements made in I 1972-74 by Wollongong Council gave an average nitrate concentration of only 3.4 mg/L. Over the following decade, the concentration has doubled but is still much less than expected. I The mean concentrations at locations I and 2, in the northern end of the lake, were higher than the other six locations, reflecting the lower water quality caused by drainage I from the heavily urbanised catchment area surrounding this part of the Lake. (f) Phosphate
Eutrophication is a term to describe the state of a body of water which has an excess of I plant growth in it, resulting from an oversupply of nutrients (principally phosphates( to the body of water. An estuary could be considered to be eutrophied when the phosphate concentration exceeds 90 ig/L. As the concentration of phosphate in Lake Illawarra was observed to exceed 90 pg/L on 19% of occasions and to reach a maximum 180 p.g/L, the I lake can be considered as highly eutrophied. This is in agreement with the finding of a 1976 study conducted by Wollongong University on behalf of Wollongong City Council I• (Reference I ) that the lake was eutrophied by sewage and erosion silt input. The surface phosphate concentration averaged 58 p.g/L and ranged from 14 i.g/L to 184 pg/L. During the period 1972-1974, the concentration ranged from 2.1 to 68.5 p.g/L (I No mean value was given. These results show that the moderately eutrophic conditions I of the early 1970's have deteriorated, despite diversion of sewage input from the lake.
(g( Silicate I Bacterial degradation of phytoplankton releases silica into the water column. The maximum value of 2105 g/L was obtained at location I in March 1982, whilst the minimum value of 3 g/L also occurred at location I in April 1982. The mean surface I concentration was 605 p.g/L.
The lowest average silicate concentration was observed at location 5, which is influenced by tidal inflow of oceanic seawater which has low silicate concentrations. The I highest average was observed at location 8, off Macquarie Rivulet.
(h( Secchi Depth
I The secchi depth is a measure of turbidity. A 20cm diameter disc painted with black and white quadrants is lowered into the water and the depth at which the quadrants become I indistinguishable is recorded as the secchi depth.
58 The maximum, minimum and average secchi depths in the lake were 2.5 m at location I, 0.1 mat location 4 and 1.0 m, respectively. The lowest average secchi depth of 0.8 m was observed off Macquarie Rivulet where very rapid siltation of the lake is taking place. The secchi depth at this location was only 0.2 m below the lake's average, indicating the very turbid nature of the lake as a whole.
I
4.2.9 Aquatic Flora and Fauna I
Harris (References 2 and 3) of the School of Botany, University of New South Wales, carried out research on the aquatic flora of Lake Illawarra from 1972 to 1976 with partial support from an Electricity Commission grant. He found that the dominant species of aquatic plants were Zostera sp. and Ruppia sp. which were mostly restricted to a shallow area on the eastern side of the lake, as shown in Figure 4.2.9. Research published by the Lake Illawarra Management Committee in 1986 indicates there has been no significant change in the distribution of these species (Reference 4) since 1976.
Zostera sp. is the most abundant of the two species and is considered to be of ecological importance as a habitat for benthic fauna and fish species at the fingerling stage. Harris (3( I found that high nutrient levels in the sediments tend to promote the growth of algae in shallow water between the Zostera sp. beds and the lake shore. The algae can at times smother parts of the Zostera sp. beds.
The Department of Agriculture, Division of Fisheries (formerly New South Wales Fisheries Department) conducted a preliminary survey of the commercial and sport fisheries of the lake for the Electricity Commission in 1983. They found that amateur finfishing and prawn fishing I pressure was heavy and similar to that found in other New South Wales estuaries. The greatest concentration of anglers was found at the Lake's entrance, Warrigal Rock, the northern shore and Tallawarra Power Station outfall canal.
Based upon the average annual commercial fish catch, Lake Illawarra was the sixth most productive estuary in New South Wales. The commercial catch comprised 24 species, the most common being sea mullet, prawns, bream and flathead. It is estimated that about 100 commercial fishermen work in Lake Illawarra, although numbers may vary with fluctuations in the abundance of fish and prawns.
The Department of Agriculture recommended that a detailed study be carried out to determine the baseline conditions with respect to fish and crustaceans in Lake Illawarra. As a result of this recommendation, the Electricity Commission has arranged for a two year study to be carried out by the Fisheries Division of the Department of Agriculture, which commenced in December 1986.
P1 b
4.2.10 Acoustic Environment
The existing acoustic environment around the project area is influenced by traffic on main roads, trains on the South Coast Railway, air traffic and farming and industrial activities. I Noise surveys were carried out by the Commission at the nine locations shown in Figure 4.2.10. At four locations the noise was monitored continuously over a three week period. At the other five locations, about four half hour noise samples were recorded at various times during the day and night.
The results are given in Table 4.2.10 and show that the nighttime background noise levels of the area were in the range of 28-39 dB(A), whilst the daytime background noise levels were in the range of 32 to 42 dB(A(. The higher levels were recorded at locations closer to the main roads. Variations between the daytime and evening background noise levels at each survey location were small. I 59
I I - Lake Heights A I A - - I - - - Koorawarra I Bay
I Lake Illawarra TALLAWARRA POWER STATION I 0 - I. -- - -- - Bevans- I :- Island -'--- - - Windang I -A Haywards A "— Bay I -.- A A A
I - A - Zostera A I. A Oak Flats Ruppia Lamprothamnion I A Gracilaria I 0 1 2kms I TALLAWARRA POWER PROJECT Aquatic Flora in I Lake Illawarra I FIGURE 4.2.9 A A
Reproduced by permission of the Director, I ,4-.nI P. , P.IAI I i
I 1z
S 2 I .1 li t •
L4O I I TALLAWARRA POWER PROJECT I I r'.rin \ Long term noise Noise Survey LI monitoring site Location Plan I A Short term noise SI monitoring site FIGURE 4.2.10 fl Residence I
U TABLE 4.2.10 I BACKGROUND NOISE LEVEL SURVEYS Measurement Mean Noise Level L 90 dB(A) (FigureSite 4.2.I0) Daytime Night-time
LI 42 35 I L2 34 30 L3 32 28 [4 38 31 I SI 37 29 S2 33 29 S3 34 31 S4 38 39 I S5 35 36
I 4.2.11 AirQuality I . (a) Particulate Deposition
The State Pollution Control Commission has a network of 12 dust deposition gauges in I the Wollongong/Tallawarra area as shown in Figure 4.2.1 1(a). The nearer of these to Tallawarra Power Station are at Dapto, 3 km to the north, and Albion Park, 4 km to the south.
I The contents of these gauges have been collected and analysed and used to estimate deposition rates. Records for the period September, 1975 to lune, 1985, have been made available by the State Pollution Control Commission and these results are presented I graphically in Figure 4.2.11(b). The average deposition rate in the area is 3.0 g/m2/month, whilst 95% of the measured deposition rates are below 8.8 g/m2/month. The average deposition rates at Dapto and Albion Park are 2.8 and 2.5 g/m2/month, respectively. These are lower than the SPCC interim criteria of 4 g/m2/month considered as the "inconsistent" level at which a loss of amenity would first be perceived, and well below the "unacceptable" level of lO g/m2/ month.
Whilst no microscopic examination of the material collected in these gauges has yet been made, evidence from the 153 gauges monitoring areas around Central Coast, Upper I Hunter Valley and Western Coal fields power stations suggests that most of the material would be expected to be of natural origin, such as sand and clay. Microscopic analysis does not lend itself to absolute quantitative results. However, it does provide a qualitative estimate of the contribution of fly ash emissions from power stations to the I dust deposition rates in surrounding areas. Results from the 153 gauges show that the average proportion of fly ash in the samples is below I %. It is a reasonable assumption that fly ash would make a lesser contribution in the areas around Tallawarra, given that I fabric filters are installed there.
I
I
I 62 Port Kembla Lake Heights
Dapto
( TALLAWARRA POWER Lake STATION • 0 Illawarra ('I
Windang
Oak Flats
Albion Park Sheiltiarbour
LEGEND
DUST GAUGE DUST GAUGE & SULPHUR DIOXIDE 0 3kms MONITOR
LOCATION OF AIR QUALITY MONITORING STATIONS Figure 4.2.11(a)
(b) Sulphur Dioxide
The State Pollution Control Commission operates a continuous recording sulphur dioxide monitor at Albion Park. This monitor was installed in October, 1983. The Commission has been publishing reports of its results of air quality monitoring. In these reports the maximum hourly average sulphur dioxide level at Albion Park between October, 1983 and December, 1984 was quoted as 154 gIm (5.4 pphm). The maximum 24 hourly average sulphur dioxide concentration was 37 .igIm (1.3 pphm) for the same period. These levels are below the widely accepted World Health Organisation (WHO) air quality goal which stipulates 200 g/m3 as the level of 24 hourly average ambient sulphur dioxide concentration not to be exceeded more than 2% of the time.
Results of field investigations carried out by the Commission in the region in collaboration with CSIRO (Reference 5) suggest that the contribution of the existing Tallawarra Power Station to ambient sulphur dioxide levels is small.
63 I SEPTEMBER 1975—JUNE 1985 I 100
I io-
I LU
I Ln a. I LU Oio o ab 60 80 100 I % OF OCCURRENCES LESS THAN OR EQUAL TO DEPOSITION RATE
I. WOLLONCONC AREA PARTICULATE DEPOSITION RATES I Source of Data: State Pollution Control Commission Figure 4.2.11(b) 4.2.12 Minerals
There are no known mineral deposits within the project boundaries, except for the coal in the I Huntley Colliery Holding. I II. I I I 64 I
I I 5. ENVIRONMENTAL SAFEGUARDS AND IMPACTS
This section of the document describes the changes to the environment which may be expected to result from the construction and operation of the power station and the proposed safeguards to mitigate against adverse impacts.
I 5.1 THE COMMUNITY A detailed study has been carried out into the impact of the project on the community and infrastructure of the Wollongong sub-region. The findings of the study are summarised below.
5.1.1 Population and Employment
The present permanent workforce of 363 at Tallawarra Power Station is expected to increase U by about IOU persons as a result of the extensions, with a workforce structure as shown below. The largest increase will be in the non-trades category, with about 60 additional unskilled workers being required. Table 5.1 .1 (a) compares the projected and the existing workforce I structures. I Projected Existing
Professional 26 14 I Operating 71 66 Supervisory and 82 47 Subprofessional Technicians and 61 72 I Trades m en Clerical 25 16 Non Trades 204 146
469* 363*
* Does not include apprentices
The workforce at Huntley Colliery is not expected to increase. However, the supply of coal for a second unit could increase mine employment and is expected to add some stability to the I mining industry in the region. The present workforce at the power station and colliery account for less than I % of the total employed in the Wollongong sub-region and the increase in permanent employment will I only marginally affect the regional economy. During construction of the power station, a transient workforce peaking at approximately 1400 persons will be required. It is estimated that labourers and skilled non-trades workers will I account for around 55% of the workforce on average over the construction period. Much of this section of the workforce will probably be drawn from local labour markets. The remaining 45% will either be building and metal tradesmen or supervisory staff. This group is likely to be recruited from outside of the region, either as part of the contractor's established teams or I because special expertise is required that will not be available locally.
It has been assumed that a third of the construction workers would be drawn from outside the region and that half of their net wage would be repatriated to other regions. The application of an employment multiplier of 1.65 to the five-sixths of wages assumed to be spent locally, gives the project total employment figures, both direct and indirect, as shown, in Table 5.1.1(b).
68 I I TABLE 5.1.1(b)
Year Relative to 1St Direct Employment Generated Total Employment Unit Operation Employment
60 33 93 —4 150 81 231 I 250 135 385 —3 350 190 540 450 244 694 —2 650 352 1002 950 515 1465 —1 1250 677 1927 1400 758 2158 0 1250 677 1927 800 433 1233 +1 300 163 463 50 27 77 i During the construction phase, the inflow of funds generated by the presence of a large transient workforce and contracts for various parts of the project will provide stimulus to the Region's economy.
The project will create employment opportunities for existing unemployed, particularly those in the large unemployment categories of unskilled labour and youth, in both the short term, and to a lesser extent the long term.
5.1.2 Commercial and Industrial Facilities
It is expected that existing commercial and industrial facilities will have capacity to handle I the impact on the sub-region during construction.
5.1 .3 Community Support Facilities, Services & Housing
The impact of the development on the housing market is difficult to assess, as the project is within the boundaries of a large urban area. However, a consultant has projected demand for accommodation in the light of previous power station developments and the existing regional labour and accommodation markets. He considered three accommodation categories, namely, hostels, rental (including caravans and guest houses) and owner- occupied housing.
The demand for hostel accommodation is assumed to come from non-local labour which consists of either single persons or married persons with family resident beyond a daily commuting distance. Of the remaining imported labour, a large proportion would be expected to be tenants and only early arrivals are likely to be purchasers. The remaining people employed directly or indirectly are assumed to be local persons and are not likely to generate significant net additions to households.
On this basis, it has been estimated that the development will generate net additions to housing demand in Wollongong and Shellharbour Local Government Areas for the first five years of the construction programme.
Demand by purchasers in these years is predicted to peak at 107 houses five years before operation, whilst 97 houses is the predicted demand three years before operation. These figures are about 10% of the total forecast demand for houses (a surrogate for new construction of owner-occupied dwellings) in these years, and much less than the fluctuations that may be expected from year to year (Ref. Section 4.1.5). Therefore, the impact could not be construed as significant in aggregate upon the two local government areas of Wollongong and Sheliharbour. Table 5.1.3 summarises projected house purchase demands during the period. ::nstructi0 I I I TABLE 5.1.3
PROJECTED HOUSE PURCHASE DEMAND BY CONSTRUCTION I WORKFORCE
Year Relative to 1st Unit Operation —4 —3 —2 - I 0 + + 2
I Net Household Purchases by Construction 26 76 65 107 97 —145 —181 Workforce
I It could be argued that the impact of housing demand would be more localised rather than spread over the whole of the local government areas. This argument cannot be sustained. Firstly, most of the land for new housing lies between Figtree and Warilla a 15 minute I commuting zone by private car. Secondly, because the impact of job shedding has been greatest in the arc spreading from Port Kembla to Dapto, the supply of existing houses should be relatively greater than other parts of the region. Thirdly, more than two-thirds of the total I stock of housing in the region is within about a half hour car journey from Tallawarra. Finally, the distribution of residences of existing Tallawarra staff is widely dispersed across the Region, and could be indicative of location of residences chosen by the project workforce. I Based on recommendations in the Department of Environment and Planning's 1982 Circular 42, the demand for new community facilities created by the development would be as follows: Children's Centre I Tennis Court Neighbourhood Park (equivalent to two residential lots) 3
The Department of Education has adequate capacity to absorb additional school children generated by the construction workforce and demands for other services such as health and police are not considered significant. Given the diverse nature of the housing demand, it is I expected that the impact on existing facilities would be small.
5.1.4 Transport Facilities
The Department of Aviation have advised that the proposed I SUm high chimney is acceptable, subject to the provision of obstruction lighting and marking. The chimney is not I expected to restrict current usage of the Albion Park Aerodrome. Existing road systems and the F6 Freeway under construction by the Department of Main Roads are considered to be adequate for general construction traffic although some l disruption to traffic flow would be expected from the transport of large items of plant. However, it is the Commission's intention to utilise the rail system as much as possible for the transportation of large, heavy items of plant to site. Additionally, it is proposed to I assemble plant in the "Large Item Assembly Area" shown in Figure 3.1(e), with the net result that, in many instances, the components of plant, and not the assembled product, are transported to site. I For coal obtained from private suppliers, the supply of coal by rail would require an estimated four trains daily, which is within the existing line's capabilities. A rail loop would be constructed for unloading purposes.
5.2 PHYSICAL ENVIRONMENT
52.1 Land Use
Land will need to be acquired for the coal transport corridor, rail facility and for ash disposal buffer zones at Mt Brown and No. 3 Ash Storage. The area is determined by the actual size of the works as well as land for noise buffer zone areas. Whilst the buffer zone areas would be alienated from the point of view of dwellings, they would still be available for other activities, such as grazing or industrial uses.
70 I 5.2.2 Soil Conservation
Special attention will be given to flooding, drainage, soil erosion and slope stability during the design and constrution phases of the project. Existing native timber and established plantings will be retained wherever possible.
The bulk of the topsoil stripped during the earthworks phase of construction will be stockpiled and used for restoration of final earth surfaces. The remainder will be stockpiled for the initial stages of rehabilitation of the No. 3 ash dam.
5.2.3 Climate
The construction and operation of the power station will have no measureable effect on the I climate of the region.
5.2.4 Flooding
The flood levels in and around the main station area are principally determined by the flood levels in Lake Illawarra. The main power station area is located clear of Duck Creek and all I other significant watercourses and will not obstruct any flood flow into Lake Illawarra and thus its construction will have no effect on flood levels in the area.
The coal conveyor and the rail loop have the potential to affect and be affected by flooding but will be designed so that they are adequately protected and that the I in tOO year flood levels are not increased outside of Commission property boundaries.
Although no decision is possible at this stage regarding a coal transport system for a second unit, the same principles of flood estimation and design will be applied to ensure that works undertaken in conjunction with the power station do not significantly increase flood levels from a I in IOU year rainfall event.
5.2.5 Archaeology, Flora, Fauna and Heritage
Within the limits of accuracy of the archaeological survey conducted to date, it is clear that some aboriginal sites in the "Logbridge Forest" could be impacted by the proposed coal conveyor route. The final route, however, will be carefully located so that no site of any significance is disturbed or alienated by the conveyor.
In addition, subsurface testing will be carried out where the conveyor crosses Duck Creek east 01 of the highway during the detailed design of the works, in consultation with the National Parks and Wildlife Service, as this area has the highest probability of containing relics. Should any further sites be discovered during the course of construction work, the National Parks & Wildlife Service will be notified as required by the National Parks & Wildlife Act.
The flora/fauna Consultant's report recommends that the coal transport corridor avoid passage through the ecologically valuable low open forest ("Logbridge Forest"). In attempting to achieve this goal, the Commission needed to balance other economic, engineering, and environmental considerations. In particular, if the conveyor were to be moved further southwards than the proposed route, and hence avoid the forest, noise levels at a number of residences were predicted to be unacceptable. The proposed route, which passes through the south-western fringe of the forest, cuts off a relatively small portion of the forest and at the same time minimises the number of residences which would be adversely affected by noise.
There is a distinct possibility that the rare and endangered orchid species Plerostylus gibbosa exists in "Logbridge Forest". However, this cannot be verified until the orchids flower, which occurs infrequently. The Commission will initiate further surveys in the forest in and around the proposed coal conveyor route to ascertain the existence or otherwise of this rare species. The route will be moved to avoid any rare orchids. I 71 I I Tree planting of selected species will be carried out along the coal transport route for the amelioration of the visual impact. This will have the added advantage of increasing bird and arboreal mammal habitats as well as creating a wildlife corridor from the escarpment to near I Lake Illawarra. I No listed heritage items will be affected by the development. 5.2.6 Water Quality Water quality is discussed under two headings: (a) Drainage and Process Water and (b) I Condenser Circulating Water. (a) Drainage and Process Water I The various drainage and process water systems are discussed below. Sewage Treatment
Effluent from the sewage treatment system will be disposed of by spray irrigation. No I adverse impact on the groundwater or run-off from the irrigated area is expected.
Construction Drainage I The Commission is well aware of the problems of sedimentation in Lake lllawarra. To . ensure that run-off from the site during the construction period does not add to the sediment load on the Lake, construction areas will be drained and the run-off so collected I directed to a settling basin where solids will settle out. Clean water overflow from the basin will be directed to the Lake via Wollingurry Creek.
Uncontaminated Drainage
This does not require any treatment and will flow directly to the outfall canal.
Contaminated Drainage Through a system of settling basin, oil/solids/water separator, and a collection basin, the drainage water will be in a suitable condition to be recycled as station washdown water or used as feedwater to the furnace ash handling plant. The system represents efficient use I of this drainage and no adverse impacts are expected. Chemical Plant Drainage I This will be neutralised, if necessary, and used to condition fly ash. No impacts of any significance are predicted from the proposed use of this drainage.
Coal Handling Plant (CHP) Drainage
I Drainage from the CHP will be recycled to the CHP washdown system after it has been through an oil/solids/water separator, a primary desilting basin, and a settling basin. Discharge from the settling basin to the Lake will occur only during storms with a return I period greater than I in 10 years. Ash Storage Area Drainage I This will be collected in a basin where solids will settle out. The overflow water from the basin will be used to spray the site for dust control purposes. As for the CHP basin, discharge from the basin will occur only during storms with a return period greater than I I in 10 years. (b) Condenser Circulating Water
The main source of water discharge from the power station site is the condenser I circulating water. The thermal effects on the lake of this system have been studied for the A and B station operation and the studies have shown that the increased water temperatures result in a 5% decrease in dissolved oxygen concentrations in close proximity to the outfall. This decrease is insignificant environmentally. A similar decrease I is expected to result from the operation of the new station. All other water quality parameters such as pH, phosphate, nitrates, silicates and Secchi depth were unaffected I by the discharge.
72 I Studies of other operating power stations, such as Munmorah and Vales Point which have greater generating capacity than the proposed development, reached similar conclusions. It is accordingly concluded that a similar insignificant impact upon lake water quality by the proposed project can be expected.
A description of the effects of the circulating water on the lake is further discussed below:
(I) Temperature
Approximately 42 m 9/s of cooling water will be required for the two 660 MW unit operating under normal conditions. The temperature of the water discharging from the outfall canal into Lake Illawarra will depend on the natural temperature of the lake, the climatic conditions, the station's electrical output and the attemperating water flow.
The attemperating system will pump water directly from the intake canal to the outfall canal when needed to reduce the outfall temperature. This will ensure that the temperature of water entering Lake Illawarra will not exceed 35°C for more than 0.5% of the time over a year. The temperature will rapidly decrease as the water spreads over Lake Illawarra such that the summer cooling field would occupy about 10% of the lake surface area.
The Commission has carried out extensive studies over many years into the discharge of heated water in lakes. These studies include analytical heat balance procedures supported by field measurements at Lake Liddell and the salt water lakes of the Tuggerah and Macquarie systems which are used for cooling by the Munmorah, Vales Point, Eraring and Wangi Power Stations.
The procedures used for the prediction of cooling fields for Tallawarra Power Station are summarised below.
The Use of an Hydraulic Model
A model of Lake Illawarra was constructed and a heater with controlled flow and I heat rates used to simulate the flow conditions which will result from the operation of the power station. I A flourescent dye was used in the model to establish the flow patterns resulting from various inlet and outlet arrangements. This information was used to select the optimum arrangement, with a view to maximising the recirculation time of the water, therefore minimising the probability of recirculating heated water.
Having determined the optimum arrangement of inlet and outfall, the model was run to obtain the shape of the model cooling field under various operating conditions. This technique can only model the shape of the cooling field and not 01 the absolute temperature distributions because ambient weather and other environmental factors cannot be incorporated in the model. I The Use of Heat Balance Equations
Heat balance equations, which have been verified in the field, are used to calculate the rate at which the temperature of the water will be reduced by processes such as convection, conduction and radiation for a given set of environmental conditions. This procedure enables the area enclosed by the isotherms (lines connecting points of equal temperature) to be predicted for the actual lake.
Prediction of Cooling Field under Field Conditions
lsotherms are plotted which conform in shape to those established by the hydraulic model, and in area] extent to those calculated by heat balance equations. I
The method has been checked by carrying out field measurements during the operation of the existing station, then running the model to simulate these operating conditions and the existing outlet/inlet arrangements. There was a satisfactory agreement between the measured cooling field and that predicted by the method described above.
73 I calculate net monthly freshwater exchanges corresponding to the period of records. That is, knowing the salinity in the lake at the beginning and end of a month and the daily U tidal flows it was possible to estimate the amount of freshwater added to or lost from the system in that month.
The reject heat from the proposed power station was estimated and used in conjunction I with climatic data to calculate the additional evaporation of lake water due to the station's operation. This data set was combined with the net freshwater exchange data to predict monthly salinity values in the lake when the power station would be I operating. The conclusions of the study are as follows:
1. Past records show that the lake salinity varied between 8.7 and 42.5 ppt and exceeded I the average salinity of the ocean of 35.3 ppt for 16% of the time. The mean value was 28.5 ppt.
2. The long term effect of the power station on the salinity of the lakes will be to I increase the mean and range of lake salinity by 0.9 ppt. This is considered to be of no ecological significance. Hypersaline conditions are expected to occur an additional 2.7% of the time. I Ferrous Ion Dosing Experience from other salt water lake cooling systems demonstrated a need to protect copper base tubing in condensers from corrosion. This is achieved by adding free I ferrous ions at very low concentrations to the inlet cooling water in the form of ferrous chloride or sulphate.
Although investigations are being carried out into alternative tubing materials (such as titanium) which do not require dosing, current technology and economics favour the continued use of copper. Accordingly, the Commission proposes to continue the practice of ferrous ion dosing. However, approval from the State Pollution Control I Commission will be sought and any conditions imposed by that Commission will be adhered to.
Mechanical Cleaning of Condenser Tubes To clean condenser tubes and hence maintain a high unit operating efficiency, the use of sponge rubber balls is rapidly becoming the accepted world-wide norm for mechanical condenser tube cleaning systems. Recent environmental legislation, particularly in the I USA, limiting use of chemical marine growth inhibitors, such as chlorine, may further encourage this trend.
During the operation of any sponge rubber ball cleaning system however, "accidental" I discharge of sponge rubber balls into the outfall canal may occur because of equipment malfunction. Design measures will be incorporated to prevent this occurring.
I 5.2.7 Aquatic Flora and Fauna The power station could potentially impact the flora and fauna within the lake through the operation of its cooling water system.
Design features will be incorporated in the Tallawarra Project to mitigate adverse impacts from the cooling water system. These safeguards, along with predicted impacts, are discussed I below in relation to the various flora and fauna. (a) Aquatic Plants Harris (Reference 3) found that nearly all seagrass growth in Lake lilawarra occurred on I the eastern side of the Lake near Windang Peninsular, Bevans Island and in Griffins Bay. Extensive growth was also observed at the mouth of Haywards Bay and Mullet Creek. All these areas are outside the predicted cooling field of the power station and so no effect I upon these seagrasses in the lake is expected. The very small growth of Zoslera (the dominant species of seagrass in the Lake) in the existing Tallawarra Power Station outfall canal, observed by Harris (Reference 3), may disappear due to increased water velocity. I Such a loss would not cause a significant reduction in total biomass of Zos(era in the lake. 74 1 I The method was used with various combinations of operating and environmental conditions. It was found that the extent and disposition of the areas of heated water in Lake Illawarra at any time will depend on the season of the year, the station output and the weather conditions (notably wind speed and direction) over the preceding period of about 14 days.
The following table shows the estimates of the areas of the lake over which selected temperature increases will occur as a result of 2 x 660 MW unit generation. TABLE 5.2.6
ESTIMATED AREAL EXTENT OF SELECTED WATER TEMPERATURE INCREASES I
Ambient Conditions Range Above Ambient Area of Lake Surface Affected
(Total Lake Surface Area = 35.8 km2 )
Summer
28tC + 8tCto +4tC 1.12 km2 With Attemperation + 4tC to + 2tC 3.83 km2
Winter I ltC + l 2tC to +4tC 4.15 km2 Without Attemperation + 4tC to + 2tC 6.25 km2
The areas of lake water surface shown in the table have been assessed for the two extreme cases of a summer natural lake water temperature of 28tC and a winter temperature of I ltC. Although the table shows figures for the two units operating at a 100% capacity factor, it is highly unlikely that both units will be operating at full capacity during summer, and if they were, it would not be for a sufficient duration for a steady state cooling field to be established in the Lake. Therefore the figures for two units operating in summer can be taken as being conservative.
The manner in which the condenser circulating water and the lake water will interact is described below.
In the immediate vicinity of the outlet into Lake Illawarra the discharging water will create a zone of mixing in which the water will be at the same temperature over the full depth. This zone will not extend beyond a distance of about 500 m from the outlet.
Beyond the fully mixed zone, the differences in the density of the lake water and the warmer incoming water will create stratification with the heated water forming a surface layer on top of the colder lake water. This stratification will occur whenever the difference between the lake water and the circlating water temperature is more than approximately 2tC. Due to stratification the lake bed temperatures in this zone will remain approximately at natural values.
Beyond the stratified zone the dissipation of heat by convection, conduction, evaporation and radiation will have reduced the temperature of the warmer surface layer to the extent that the density difference is no longer sufficient to sustain stratification and mixing will take place. I (ii) Salinity
The effects of power station operation on the salinity of Lake Illawarra have been predicted using a salt and water balance for the lake. The lake was modelled as a system open to the ocean in which fresh water inflows reduce the salinity of the lake water while evaporation, by removing fresh water from the lake, increases lake salinity. Tidal inflows bring in seawater with a salinity of 35.3 ppt, and tidal outflows carry lake water from the system.
While the tidal flows can be calculated the freshwater components are difficult to measure or estimate due to the variability of the catchment runoff.
To overcome this problem, salinity records taken from the late 1950's to early 1960's and during the 1970's and 1980's were used in combination with daily tidal exchanges to I 75 Recent surveys arranged by the Lake Illawarra Management Committee show that Halophila ovalis has appeared in the Lake. H. ovalis was observed in the outfall canal of Vales Point Power Station following its dredging. A similar result might occur in the U outfall canal in Lake Illawarra, given that the species already exists in the lake. (b) Shallow Water and Deep Water Benthos j Observations in Lake Macquarie and the Tuggerah Lakes show that most shallow water benthos (bottom dwelling organisms) are associated with seagrass beds. The loss of benthos in the seagrass bed in the outfall canal when the dredging referred to in (a) above is carried out is not considered to be significant, as the lake contains several I square kilometres of seagrass.
Due to the stratified cooling water discharge, the impact upon deep water benthos is expected to be insignificant. Studies conducted at Vales Point and Munmorah Power Station support this conclusion. (c) Zooplankton I Zooplankton are microscopic animals which live in the lake water. They can be separated into two broad groups, namely those which are the larval stage of larger aquatic fauna, and those which remain microscopic as adults. Entrainment of zooplankton in cooling I water intake water is unavoidable due to their small size. Laboratory tests have been conducted by the Commission to determine the thermal tolerance of the dominant permanent zooplankton in New South Wales coastal lagoons. I It has been found that mortality rates are a function of the discharge temperature of the cooling water and the length of time the zooplankton are kept at elevated temperatures. A mathematical model which utilises discharge temperatures, entrainment times, population growth rates and lake water recirculation rates was used to predict the I impact of the cooling water system on permanent zooplankton populations in Lake Illawarra.
I Impact predictions were made for the 2 x 660 MW power station cooling water system, attemperated to 35tC, and an unattemperated cooling water system. Modelling was carried out using inlet temperatures for the summer of 1981, which had the highest recorded exceedance of 28tC, to give a conservative estimate of impact. The predictions I were made for the units on full load.
The results obtained for the power station were an average 4.1% reduction in lake zooplankton population for attemperation to 35tC and for an unattemperated power I station, a 7.3% reduction was predicted.
Even under the most adverse condition of the units operating at full load during I• summer, the predicted impact upon zooplankton is considered to be insignificant. (d) Fish and Prawns The preliminary fishery study, conducted by the Fisheries Department in 1985, found I the same commercial and recreational fish species in Lake Illawarra as in Lake Macquarie and the Tuggerah Lakes. The ecological studies of fish in these lakes are considered applicable to Lake Illawarra.
I Results of studies from the northern lakes show that the commercially and recreationally important fish species breed at sea and that the larvae enter the Lake and go to the seagrass beds where they remain while juveniles. No larvae were observed to be I entrained in the cooling water system. As the seagrass beds and lake entrance of Lake Illawarra lie outside of the cooling field, the influence of the cooling water discharge upon fish larvae would be negligible. I King and school prawns breed at sea and the post-larval stages enter the Lake and migrate to the seagrass beds, thereby avoiding entrainment in the cooling water system. However, the greasyback prawn breeds in the Lake and its larvae could be entrained in I the cooling water system. Thermal tolerance studies of greasyback prawn larvae show that their thermal tolerance was 37tC for one hour exposure. As the cooling water discharge would rarely, if ever, reach this discharge temperature, the impact on the I larvae would be negligible. 76 I The cooling water system will be designed to exclude the passage of larger biota. Trash racks, screens and filters will be located in various positions in the vicinity of the cooling water pumping station. These screens will remove all material in the inlet water with a dimension larger than about 10 mm from the water before the water enters the circulating water pumps. The screened material, which will include suspended aquatic organisms, will be washed off the screens with lake water and returned to the lake via the outfall canal. Whilst this is the current proposal for filtered material, the Commission will investigate other options, such as removing jellyfish from the filtered material and disposing of these on land, as the overabundance of jellyfish has been perceived by some lake users as a problem.
Tests have shown that, provided adequate flushing water is used when sluicing the screenings back to their source, most of the aquatic life will survive. Provision is being made for an adequate supply of flushing water and to increase that supply in the future if that is shown to be desirable.
The thermal tolerance of some commercial fish species found in the coastal lakes has been determined by Clark (Reference 6). He found that the thermal tolerance was 37.ItC and 37.2tC for sea mullet and sand mullet respectively. This resistance to high temperature corresponded with the observation by Clark that mullet accumulate in the outfall area of the Munmorah Power Station during summer.
The fish commonly taken by anglers, luderick and bream, were found to have thermal tolerances of 34.1tC and 33.2tC respectively by Clark (Reference 6). Observations of fish caught by amateur fishermen at the cooling water outlet areas of existing power stations and the results of netting carried out by New South Wales State Fisheries (Reference 7( show that these species avoid outlet areas during summer, indicating that these species avoid temperatures which are unfavourable to them.
The New South Wales State Fisheries found that Munmorah Power Station had not had an adverse effect upon the commercial fish and prawn catch or recreational fishing of Tuggerah Lakes. In fact, the amateur fish catch in the outlet and inlet areas had improved. Similar results are expected with operation of the proposed Tallawarra units.
5.2.8 Visual Impact (a) Power Station Site The visual impact of the proposed development on the surrounding area has been assessed using a perspective plotting computer program.
Representative views of the proposed development from various locations around the site are shown on Figures 5.2.8(a) and (b). I The studies show that from viewing points on the northern, eastern or southern foreshore of Lake illawarra, the view of the proposed works at Tallawarra Power Station is quite diminutive due to distance. In some cases, only the upper level of the structures and the chimney are visible as the topography between the viewing point and the station obscures the new works. A colour scheme will be selected for the metal clad structures and masonry buildings of the proposed works to blend them into the existing landscape.
The existing station is visible from a short section of the Princes Highway west of the station. The existing and the proposed works will be hidden from view from the Highway in the long term by the No. 3 ash storage area. In the interim, progressive planting of vegetation and moundings will be incorporated into the landscape design so as to ameliorate the visual impact. Both the No. 3 and No. 4 ash storages will be progressively vegetated and the ash mounds will be constructed to give a natural appearance that fits in with the surrounding landscape.
The coal storage area will be screened by ungated mounds which follow a north-south 'U' shape around the area. I With the adoption of the above measures, it is considered that the overall impact on the visual amenity of the surrounding areas will be acceptable. 1 77 -
'- -
4. -- -
- - ) *--4 ft ft VIEW FROM LOCATION 18
I / ALLAWARRA SITE 9) Lake .. 18 TALLAWARRA POWER PROJECT UcD ))Illawarra Views of Power Station from East and South East
02km FIGURE 5.2.8(a) . - • - . r
VIEW FROM LOCATION 5
TALLAWARRA POWER PROJECT Views of Power Station from North East and South West
FIGURE 5.2.8(b) I 5.2.9 Acoustic Environment I Investigations have been carried out to determine the effect of the proposed development on the acoustic environment, using a combination of field measurements and computer modelling.
I According to SPCC guidelines, and consistent with AS 1066 "Noise Assessment in Residential Areas", noise levels from general industrial sources are not of significance if they do not exceed the existing background noise levels by 5 dB(A) or less. The Commission's objective is to ensure that this level is not exceeded outside of the Commission's property boundaries I as a result of the Tallawarra Project. Acoustic goals for residences surrounding the project area have been established using field measurements and the SPCC guidelines and are shown in Table 5.2.9. I
TABLE 5.2.9 I ACOUSTIC GOALS FOR RESIDENCES SURROUNDING THE PROJECT AREA
Activity Area Time of Acoustic Goal for Affected day Residences I
GENERAL Within 400 m of Princes Day LI0 (48 dB(A) ACTIVITY HwyorFôfreeway Night L!0(4OdB(A) I (Station, 400m to I km from Princes Day Ll0 (43 dB(A) conveyors, coal Hwy or F6 freeway Night LI0(35 dB(A) handling plant, 1 etc). Within I km of animal Day Ll0 (41 dB(A) products rendering plant, Night LI0 (38 dB(A) I Yallah Road Within 600 m of Huntley Day L!0 (43 dB(A) Colliery coal washery Night L10 (35 dB(A) I Area around Yangar Pt. Day Ll0 (43 dB(A) Night LI0(36dB(A) I Otherareas Day Ll0(38dB(A) Night LI0(35dB(A)
Lmax(8OdB(A) I RAILTRAFFIC All All and Leq(55dB(A)
80 I TABLE 5.2.9. (cont.)
Activity Area Time of Acoustic Goal for Affected Day Residences
CONSTRUC- Ex- Ex- Ex- TION (Earth posure posure posure moving period Period Period equipment, hammering, etc.) (4wks 4-26wks )26wks 1_10 LlO( 1_10( Within 400 m of Princes Day 62 32 47 I Hwy or F6 freeway Night 55 45 40 400 m to I km from Day 53 48 43 Princes Hwy or F6 freeway Night 50 40 35 Within I km of animal Day 56 46 41 products rendering plant, Night 53 43 38 Yallah Road
Within 600m of Huntley Day 58 48 43 Collierycoalwashery Night 50 40 35 Area around Yangar Pt Day 58 48 43 Night 50 40 35 Otherareas Day 53 43 38 Night 50 40 35 I Legend: L10 - noise level exceeded 10% of the time. Lmax - maximum noise level. Leq - steady state noise equivalent in energy to noises which vary in level in a given period of time.
To achieve these goals, a number of noise reduction measures will have to be taken during both construction and operational phases and these are indicated below. Noise Control Measures Construction Phase During the construction phase, all mobile plant working on the haul road, rail loop, laying of pipelines and the ash storage site will be fitted with exhaust silencers capable I of reducing their overall noise level to at most 80 dB(A) at tO m. Extra attenuation may be necessary for plant involved in laying the coal slurry pipeline, should this mode of transport be adopted.
All blasting involved in the construction will be restricted to the hours of 7 am to 7 pm. Noise exposure from this source at the nearest residences will be controlled to ensure that an unweighted peak sound pressure level of 115 dB is not exceeded, as recommended in the State Pollution Control Commission's guidelines. Noise Control Measures -Operational Phase I Power station noise emissions will be controlled by installing items of plant which have relatively low and favourable noise characteristics for such items. Specifications for plant items to be installed at Tallawarra Power Station will include specific clauses which limit noise emission levels.
In addition to improvements in the design of machinery to meet noise criteria, some plant items (feed pumps, blowdown vents, I.D. fans, safety valves, etc.), if required, will be housed in special soundproofed enclosures or will have silencers installed so as to ensure that satisfactory noise levels are achieved within the station and at the station boundaries. I 81 i I In order to limit the extent of areas affected by noise, a 3m high steel fence will be installed on the southern side of the proposed conveyor between Huntley Colliery and Marshall Mount Road and on the northern side between Marshall Mount Road and the I transfer station adjacent to the rail loop. The building which houses the rail unloading facility will be designed using single brick T or similar material rather than sheet metal construction, as a noise control measure. in general, the Commission will undertake the noise attenuation measures necessary to ensure that noise generated by the construction and operation of the development will have an acceptable impact on the acoustic environment of nearby residences, in accordance with SPCC guidelines. The Commission will soundproof or acquire existing residences which cannot be protected from unacceptable noise levels.
5.2.10 Hazardous Substances I The measures which will be adopted for the safe use and storage of all hazardous materials will be in conformity with the Dangerous Goods Act and Regulation and all other relevant Acts and Codes of practice which relate to the handling and storage of such materials. The various safety measures which will be incorporated in the storage and handling facilities for those I substances stored on site are outlined below. I. Oil The two 1200 KI steel storage tanks will be enclosed by concrete bund walls which form basins of capacity in excess of the tanks' total capacity. An oil trap will be installed for the retention of any oil spillage in the unloading area. Early warning fire detectors and fresh water I and foam fire fighting systems will be provided.
Hydrogen I All hydrogen produced by the hydrogen generation plant will be stored in a secure open area. The plant will be provided with facilities to detect leaks and to control fire. If the hydrogen concentration reaches a pre-set level, the hydrogen generation plant will automatically shut I down. Chlorine I Chlorine will be stored in liquid form in 920 kg cylinders. The cylinders will be placed in a secured open area and instrumentation will be installed to automatically shut down the dosing plant if a chlorine leak is detected.
I Sulphuric Acid Sulphuric acid (98%) will be stored in steel tanks which will be surrounded by lined concrete bund walls which form basins of capacity greater than the tanks' total capacity. Provision will I also be made for the neutralisation of the acid in case of spillage. I Caustic Soda The tanks for storing the 50% caustic soda solution used on site will be enclosed by lined concrete bund walls to contain leaks. The design will also incorporate facilities for the I neutralisation of An hydrous Ammonia
20 t storage tanks will be used to store the ammonia delivered to site which will then be I diluted to a 5% solution and stored in stainless steel tanks. Any spillages will be contained and diluted before flushing to the ash storage area. I Hydrazine-Aqueous The hydrazine will be delivered and stored in 200 L drums and facilities will be provided for I the retention, dilution and flushing of spillages, 82 i 5.2.11 AirQuality
(a) Emissions from the Chimney The effect of chimney emissions upon existing air quality depends on two factors: the quantity of pollutants emitted from the stack and the degree of dispersion these emissions attain before reaching ground level where their effects are of concern.
The chimney height and exit velocity have been chosen to ensure that the emitted pollutants are dispersed satisfactorily. Greater stack heights or exit velocities could have been chosen but the substantial cost increases are difficult to justify against the marginal increase in air quality which would result. These design parameters will be subject to approval by the State Pollution Control Commission, and as shown in Table 5.2.11(b), the ground level concentrations of pollutants are predicted to be well within acceptable limits.
The various air pollutants which may emanate from the power station, in the context of their impact and the safeguards proposed to mitigate against such impact, are discussed below.
(i) Sulphur Dioxide The use of coal with a relatively low sulphur content by world standards and consequential low sulphur dioxide emission levels means that there is no need for the installation of equipment to reduce sulphur dioxide emissions. The median sulphur content of Huntley coal is 0.44%, whereas many overseas power stations burn coals having 2 to 3% sulphur.
Detailed studies have been carried out to assess the average ground level concentra- tions of sulphur dioxide which could be attributed to the operation of the proposed units. The prediction of gas dispersion is done in two parts. First, a mathematical model is used to predict dispersion from the chimney. The model is based on a Tennessee Valley Authority plume rise formula, Gaussian diffusion formula and Turner's dispersion coefficients and assumes a flat terrain. Second, wind tunnel and field plume dispersion models are used to predict the effect of the topography on the results obtained from the mathematical model and to determine an appropriate chimney height to offset the topographic effects.
The meteorological variables of prime importance in atmospheric dispersion studies are wind speeds and directions, the strengths of the vertical and horizontal components of the turbulent mixing processes, and atmospheric stability. Table 5.2.11(a) gives the sources of climatic data used in the studies. Based on data from these sources the annual average temperature for the region was estimated to be 18tC and ambient atmospheric pressure was assessed to be 1013 m bars.
TABLE 5.2.11(a) CLIMATIC DATA SOURCES
Parmeter Observing Locations of Frequency of Period of Data being Authority Observations Observations Used observed
Annual EC of NSW Tallawarra Daily at 9.00 1977 to 1985 fl average Power Station am temperature H
Wind speed EC of NSW Tallawarra Hourly 1976 to 1985 and direction Power Station averages from I continuous chart H U Cloud cover C.B.M. Nowra 3 hourly 1983 observations
83 I The highest ground level concentration have been predicted for conditions of the two units operating at continuous maximum rating, and the coal burnt having the maximum design I sulphur content of 0.5%. Estimates of the maximum three-minute average ground level concentration of sulphur dioxide under the above conditions which give highest ground level concentrations have been made for a range of chimney heights. The height at which the maximum ground level I concentration is below the level considered to be acceptable (based on estimated pollutant concentrations for chimneys previously approved by SPCC( has been adopted as the appropriate chimney height.
I The results of the study fora chimney on flat terrain are summarised in Figure 5.2.1 I(a(. From these results, it is clear that a 100 m chimney will be adequate in effectively dispersing flue gases from the Tallawarra project to ensure acceptable ground level concentrations of sulphur I dioxide, for the power station located on flat terrain.
500
15 -j 400 w wH -Jz
C) 300 10 1 o - o z CVLD tj 200
> NOTES: 1. Concentrations are three minute averages I. 2. Worst case of Station Operation & Meteorological conditions assumed to produce maximum concentrations PREDICTED MAXIMUM SULPHUR DIOXIDE GROUND LEVEL CONCENTRATIONS WITH VARIATIONS OF CHIMNEY HEIGHT Figure 5.2.11(a) I When the field plume dispersion and wind tunnel models are applied to these results, the height of the chimney needs to be increased to ISO m to take into account of the effects of the local topography. I The three-minute exposure referred to in Figure 5.2.1 I(a( is used because it represents the minimum sampling time for obtaining meaningful results. It can be used to derive results for longer periods, enabling comparisons with widely acknowledged air quality goals. Table 5.2.1 I(b( indicates such goals and the predicted concentrations due to the power station. As can be seen from the table, in every instance predicted concentrations are well below any of the corresponding goals, standard or guideline. The predicted concentrations are based on the assumption of the worst concomitant conditions outlined above. 84 I TABLE 5.2.11(b) SULPHUR DIOXIDE CONCENTRATION GUIDELINES, STANDARDS, GOALS AND PREDICTIONS Period N.l-I.M.R.C. U.S.E.P.A. Standard Predicted GUIDELINES Concentration jig/rn3 W.I-I.O. jig/rn3 Primary Secondary Goal jig/rn3 jig/rn3 jig/rn3 I 3 hours 1300111 - 85 365(21 24 hours 2601 ' 20013 ' 120 1 Annual Average 60 ' 80' 60" 60 0.9 NOTES I. Arithmetic mean. Not to be exceeded more than once per year. 98% of observations to be below this figure. Maximum permissible annual mean level. Oxides of Nitrogen Measurements at the Commission's modern power stations show that for a station operating in a manner similar to the proposed 660 MW units at Tallawarra, the concentrations of oxides of nitrogen (expressed as jig/rn 3 N.T.P. NO) are approxmately 0.85 times those of sulphur dioxide (expressed as p.g/m 3 N.T.P. SO2 ). By extending the data given for sulphur dioxide, it is estimated that the maximum value of the average annual ground level concentration of nitrogen oxides within 20 km of the site will be about 0.9 jig/rn 3 N.T.P with both the units operating. This predicted value is very low in comparison with the standard of 100 jig/rn 3 N.T.P. adopted by the United States Environmental Protection Agency. Based on these estimates, it is considered that NO emissions from the project will be such as to be environmentally acceptable. Furthermore, boiler contracts will require boiler designs to be such that nitrogen oxide I emissions, at any load, will not exceed the Clean Air Act emission limit of 2.5 jig/rn3 N.T.P. Particulate Emissions Subject to licencing by the State Pollution Control Commission, plant should be installed to remove about 99.9% of the particulate matter from exhaust gases, with sufficient reserve to maintain these efficiencies during maintenance periods. The Commission has successfully employed fabric filters to remove particulates with this level of performance at a number of its power stations and it is expected that such filters would be used at Tallawarra, unless a superior alternative becomes evident during the lead time to construction. Based on experience with similar plant at Eraring Power Station, the resulting point emissions from the stacks are expected to be around 0.05 g/rn3, which is considerably less than the maximum of 0.25 g/m3 N.T.P. permitted under the Clean Air Act. However, the maximum permissible emission rate has been assumed as the worst case for estimating the particulate deposition rates resulting from the operation of the power station. Deposition rates and their areal distribution have been estimated and are based on the frequency distributions of wind speeds and directions for various atmospheric stability classes. Contours of annual average particulate deposition rates for a two unit operation are given in Figure 5.2.11(b). A maximum deposition rate of 0.2 jig/m2/month could be expected when both units are in operation. The average deposition rate within 20 km of the site would be approximately 0.1 g/m2/month. (b) Airborne Dust 1 Dust from loose, dry materials is a potential source of air pollution, particularly during periods of dry, windy weather. The potential sources of dust are outlined below, with a 85 i I description of measures that will be taken to ensure that dust from the Tallawarra project will not be a nuisance. (i) Construction During the construction phase, stripping of vegetation and topsoil will be I necessary to carry out the project works. The loss of binding surface material may create a potential dust problem. Disturbance of topsoil will be limited to those areas required for construction and will be stockpiled for rehabilitation of I disturbed areas. Rehabilitation, including regrassing, will be carried out at the completion of construction in a particular area. I Major access roads wil be bitumen sealed while other access roads will be regularly sprayed by water cart. (ii) Coal Dust I The methods which have been successfully employed at other Commission stations will be adopted to control coal dust at Tallawarra. These include: • conveyors at ground level will be semi-enclosed by roof sheeting and wall I sheeting on one side, while elevated conveyors will have wall sheeting on both sides as well as roof sheeting; I.all transfer towers and receiving bins will be enclosed to the fullest extent p racti b I e; . a chemical will be used when required, to suppress dust in the coal handling area. All coal incoming to the long term storage area will be sprayed with a bio- I degradable agglomerate type wetting agent. Spraying equipment will be automatically activated by belt movement. The high furnace temperatures will ensure that suppressant chemicals reaching the boilers are entirely combusted, but being essentially hydrocarbon and in such small quantities, they will have a I negligible effect on air pollution; . a water tanker will be used to spray water whenever necessary to achieve direct dust suppression and to reactivate the chemical suppressant where required on I the long term stockpile. Ash Storage Dust I Effective dust control at both ash storage sites will be achieved by adopting the following procedures: I . fly ash will be transported and compacted in the "conditioned" state (condition- • ing involves the addition of small quantities of water prior to discharging into trucks to improve its handling characteristics and suppress the formation of dust); I the tailgates of all vehicles transporting ash on or around the sites will be sealed as completely as possible; I.water carts will operate during working hours to control dust on all haul roads at and within the site; only small areas of ash will be exposed at any one time on the working face; I • rehabilitation will be on a continuous basis; whenever conditions necessitate, irrigation sprays will operate to control dust. This system would be an extension to the irrigation required for restoration I purposes; . where it is necessary for ash to be exposed for long periods (i.e., some internal slopes) the ash will be stabilised with a bitumen emulsion spray, polymer type micro-agglomerating crusting agents, or by blinding off with washery refuse or I furnace ash. Furnace ash will be extracted in a relatively wet condition and would not require I further water for transport or placement. 86 5.2.12 Minerals I No known mineral deposits will be sterilised by the project. I. I. 88 6. CONCLUSION Tallawarra Power Project represents an expansion of existing power generation facilities and I apart from the coal transport corridor, will be almost entirely built on the present power station site. During construction, a transient workforce peaking at 1400 persons is anticipated, whilst a I further permanent 100 jobs at the power station are predicted to be generated. Economic benefits will flow to the region as a result of the project both directly and through the application of the multiplier effect. I A landscaping programme, including tree planting, mounding and up-grading of existing vegetation will help to minimise visual impact, as well as generally improve the appearance and amenity of the project area. I The use of appropriate noise control measures and buffer zones at and around the power station and along the coal transport route will ensure that the noise levels at surrounding residential areas are acceptable. I The project will not destroy any rare or endangered species of flora or fauna, including marine species, nor any important archaeological sites or items of heritage. I The facilities which will be provided for power station drainage, including recirculation of water used for ash disposal purposes and for washdown, will avoid the need for contaminated ,waterdischarges to Lake Illawarra except under exceptionally wet conditions. I The use of water from Lake Illawarra for power station cooling purposes is predicted not to adversely affect the Lake, based on extensive cooling field studies and assessment of the aquatic environment. I One in 100 year flood levels in the area will not be increased by the project. The principal air pollutants from the operation of the power station will be sulphur dioxide, ' oxides of nitrogen, and particulate matter. Control measures such as highly effective ash collection plant, adequate chimney height, and water spraying in coal and ash storage areas, will ensure that these pollutants are kept within statutory and acceptable limits. It is concluded that the proposal for the construction of two 660 MW generating units at I Tallawarra Power Station can be undertaken in a manner which is environmentally acceptable. I. 92 45, 7. REFERENCES I. University of Wollongong. 1976. Illawarra Lake. An Environmental Assessment Project. I Wollongong City Council and University of Wollongong. Harris, M. 1972. A Report on an Inquiry into Selected Aspects of the Ecology and Botany of Lake Illawarra, New South Wales conducted during 1972. M.Sc.(Oual) Thesis, School of Zoology, University of New South Wales. I Harris, M. 1977. Ecological Studies on Illawarra Lake with Special Reference to Zoslera capricorni Ascherson. M.Sc. Thesis, University of Wollongong. I Lake Illawarra Management Committee. 1986. Algal Growth Control in Lake Illawarra. Produced for Illawarra Region of Councils by Lake Illawarra Management Committee. CSIRO Institute of Energy and Earth Resources. 1985. Dispersion of the Plumes from the I Tallawarra Power Station. I 6. Clark, J.E.C. 1977. Thermal Tolerance of Fish from Tuggerah Lakes. M.Sc. Thesis, University of New South Wales. 7. New South Wales State Fisheries. 1980. The Impact of the Munmorah Power Station on the I. Recreational and Commercial Finfish Fisheries of Tuggerah Lakes. I. 96 APPENDIX A ALTERNATIVE COAL TRANSPORT MODES AND ROUTES As discussed in Section 3.3. of the main report, coal from Huntley Colliery is proposed to be transported to the power station by conventional conveyor, although a slurry pipeline pilot study to be undertaken may prove this mode to be more attractive. This appendix discusses the various transport modes and routes considered and gives reasons for the preference, at this time, for the conveyor option along a southern route. Truck Haulage Over Public Roads Approximately 0.58 million tonnes of coal per year is currently transported between Huntley Colliery and Tallawarra Power Station by trucks travelling on public roads. I Increasing the rate of supply to the power station from 0.48 million tonnes to 1.8 million tonnes per year would require a fourfold increase in the number of truck movements resulting in approximately one coal truck every one to two minutes between the hours 7.00 am. to 6.00 I p.m. . The transport of coal by trucks over public roads, while offering significant cost savings, is not in accordance with regional planning policies to minimise haulage on public roads and is not considered to be an acceptable option. However trucks might be used in emergencies if there is a prolonged breakdown of the coal conveyor. Pipe Conveyor Pipe conveyors are similar in many respects to conventional conveyors but the conveyor belt is formed into a tube or pipe, thus totally enclosing the material being conveyed. They do not I offer any advantage in terms of noise characteristics over a conventional conveyor and they have higher capital and operating costs. Additionally, they have only been commercially demonstrated in this country over short distances, typically 300 m. They are not considered a I viable alternative compared with conventional conveyors. I (c) Pneumatic Capsule Transport This system involves containing the material in a mobile body or capsule and it being pneumatically driven through a sealed pipeline. Two pipelines would be required, one pipe I. carrying loaded capsules to the coal storage area, the other pipe returning the empty capsules back to the coal loading station at the washery. Mechanical handling facilities are required to receive, load/unload and despatch the capsules at each end of the route. A I booster station could also be required along the route. High reliability of support systems is necessary in a large power station and accordingly, the systems must be well proven. The limited experience with pneumatic capsule transport I systems make these doubtful compared with other proven systems such as trucking or conveyor. (d) Slurry Pipeline Transport The transportation of coal by slurry pipeline involves the suspension of the coal in a fluid. The slurry is then pumped from a loading facility to a slurry separator at the coal storage area via a pipeline. A recycle pumping station and return pipeline are required to return water or special fluid to the loading facility. Preliminary studies have indicated that coarse coal transport by slurry pipeline could be viable but further development and testing would be required before its applicability could be finally assessed. Cost estimates indicate that slurry pipelines are highly capital intensive but have relatively low operating costs. 100 I I Pipelining offers significant environmental advantages. The pipeline would be buried and hence noise and visual intrusion would not be issues. In addition no buffer zone land would be required. I Rail Transport The bulk transport of coal by rail has been well established over many years. However, - because a rail system is capital intensive it is not economically viable to install a dedicated rail system over the short distance between Huntley Colliery and the power station. I Private Haul Road Two alternative private haul routes from Huntley Colliery were evaluated, namely a northern route (6.5 km), and a southern route (6.8 km(. A noise buffer zone would be established along either of these routes to ensure that noise levels outside the coal transport corridor would be acceptable. I The southern route would be the preferred route on the basis of economic and environmental con side rations. Trucking on a private haul road is a viable alternative for the transportation of coal and offers greater flexibility than other options in terms of back-loading of ash for storage off site, should such disposal become necessary. However, as indicated earlier in this document, it is proposed to restrict ash storage to within the boundaries of the existing power station site. The private haul road alternative was rejected on economic grounds after comparison with a conventional conveyor. Conventional Conveyor The use of belt conveyors for bulk transport of materials is well established. The selection of - the most suitable conveyor system requires an analysis of capital and operating costs, reliability and consideration of dust control and visual appearance aspects. I The conveyor does not have any significant environmental or technological advantage or disadvantage when compared with a private haul road for coal transportation from Huntley Colliery to Tallawarra Power Station. However, the two options are significantly different when compared on an economic basis. Although the conveyor option has a higher capital cost than the private haul road, it shows considerable cost savings over the life of the station. It is principally for this reason that the conveyor has been selected as the preferred coal transport option. I Two conveyor routes were examined, namely a northern route (6.25 km) and a southern route (6.6 km) as shown in Figure Al. Both routes would require a corridor which incorporated a noise buffer zone. Of the two routes, the southern route is preferred, principally for the following reasons: it utilises natural topography to attenuate noise; it is less affected by flooding of Duck Creek; it is more remote from existing Dapto residential sub-divisions; it does not affect the properties Avondale and Penrose, which have been listed as items of environmental heritage; it utilises existing Commission owned land at Dapto Substation. it better integrates with a rail loop. I I 101 I TALLAWARRA POWER PROJECT Alternative Conveyor Routes FIGURE Al I APPENDIX B I ALTERNATIVE ASH DISPOSAL METHODS AND SITES As discussed in Section 3.9.2 ash will be stored by dry emplacement at Mount Brown and No. 3 Ash Storage. This appendix discusses other disposal technologies which were considered and the reasons for their rejection, as well as examining alternative sites for dry I emplacement. I BI. ALTERNATIVE DISPOSAL METHODS I (a) Underground Stowage This alternative involves the placement by dry packing or hydraulic packing of ash in the I voids left following coal extraction. The mining areas at Huntley Colliery are some 9- 15 km from the power station and they are also at a considerably higher elevation. Under these circumstances the transport of ash to the I mine becomes an important factor. It is not practical, because of pumping head conditions, to pump the ash to the mine as a slurry; it would be possible to truck the ash to the mine entrance on the escarpment but it would not be practical to truck the ash to locations above I the workings for injection through bkholes because of the long transport route to the plateau via Macquarie Pass. Having incurred significant cost penality in transporting ash to the mine entrance there are I further financial penalties attached to underground stowage. A Commission of Inquiry into The Disposal of Industrial Waste on the Wollongong Plain Sub-region as Arising from the Coal and Steel Industry, which was completed in 1985, indicated that establishment costs at the I mine could amount to between $8 and $20 million dollars, as well as increasing production costs by $4 to $8 per tonne. No South Coast mines have been designed for compatibility with underground stowage and I therefore this technique is not a practical alternative for Tallawarra Power Station. I (b) Offshore Disposal This method involves the disposal of ash in the ocean by either: I I) tipping on the foreshore in exposed locations where the sea erodes the deposited ash to I beach level; (2) transportation of the ash in bottom opening barges to designated tipping areas, or 1 (3) conveying the ash by pipeline to a designated site. The Commission undertook an extensive study of ocean disposal of ash for Munmorah Power Station in the early 1960's before Munmorah was constructed. The proposal was abandoned at that time on environmental grounds and there is little chance of such a proposal gaining I approval, having regard for the greater environmental interest in and controls on such activities today. Accordingly the alternative of ocean disposal is discarded. I (c) Land Disposal (Emplacement) Emplacement is the usual means of ash disposal from power stations. Traditionally, ash I disposal in New South Wales has been achieved by hydraulic means. The ash is mixed with water and pumped or sluiced in slurry form to the disposal area. The wet ash is retained in the disposal area by constructing an embankment, such as a dam I across a valley or a turkey's nest type structure. Both arrangements require areas in which the ash can settle out so that the water can be returned to the power station for re-use or, if salt I water is used, it may be returned directly to its source after decanting from the ash pond. 104 I I The wet disposal system has two major advantages. Firstly, the ash is kept wet and therefore poses no dust problem and, secondly, the system operates successfully with very low manpower requirements at the disposal location. The dry disposal technique involves the addition of a small quantity of water to the dry ash to prevent a dust problem during transport (if by truck or conveyor) and disposal. The water used for this purpose can be of low quality, collected from the power station drainage and washdown systems. Once at the disposal site, the conditioned ash is placed and compacted by conventional earthmoving equipment and the exposed surfaces are kept damp by spraying. The emplacement is built up in layers and the visible face is progressively revegeta ted. This system will make available a wider range of storage sites as the deposits can be built up into large mounds, requiring only a small toe embankment. Dry ash can be just as easily deposited on a large expanse of flat land as in a valley. A further advantage is that it minimises the potential for seepage contamination and the discharge of contaminated waters during prolonged wet or flood conditions. I B2. ALTERNATIVE DISPOSAL SITES There are no wet ash storage sites available to the Commission within its presently owned property boundaries and in order to avoid further land acquisition for ash storage, the decision has been made to adopt the dry placement procedures. A total of up to 30 m 9 storage could ultimately be required during the life of the power station and hence the selected sites or combination of sites needs to have this capacity. Sites which satisfy the following requirements and are therefore suitable for dry storage are shown in Figure BI. proximity to the power station; (Both operating and capital costs of any ash disposal system increase significantly with distance from the power station.) avoidance of environmentally sensitive areas; absence of any adjacent residential areas; preservation of any area or item of major aboriginal or historical significance Table BI summarises the salient features of the nine sites. - The use of No. 3 Ash Storage and Mount Brown to accommodate the total station ash was chosen as the preferred option as these sites are the closest to the power station, are almost completely contained on Commission owned land, do not directly affect any existing or potential residential areas and are not environmentally or archaeologically sensitive. The principal disadvantage of this option is its visual impact on views from the lake and the freeway. However, judicious landscaping, particularly in the early stages of the development, will greatly ameliorate this. I I 105 I I (K(jIL)I\JML LINVIKUNIVILINI IPL F'LbkI\J I\JU. I) EC PROPERTY ZONED ENVIRONMENTAL PROTECTION (WETLANDS) IN LEP 38 & REFERRED I TO IN ASH DISPOSAL STUDY WETLANDS AREAS IDENTIFIED IN SEPP No. 14 & REFERRED TO IN ASH DISPOSAL STUDY I- DIS oiIMrPTISflI I I IS DCI lflITIIPflU IU U (REGIONAL PLAN No.1) I ------.- - - - - -I ------ TABLE Bi SUMMARY OF ALTERNATIVE SITES Mt Brown No. 3 Ash Clover Hill Mullet Creek Duck Creek Marshall Marshall Mount Four Oaks Yellow Rock Site Dam Site Site Site Site Mount Creek Creek Site Gully Site Creek Sfte Site (South) (West) RADIAL DISTANCE 0.5 km I km 5.5 km 6km 7km 8.5 km 9km 105km 10.5 km FROM POWER STATION APPROXIMATE Not possible to Not possible to I 20m (north arm I lOni 90m 65m 75m I lOm 90m DEVELOMENT develop for 30 x develop for 30 x only) HEIGHT FOR I0m3. 10m7. 30 x I 0m3 85m height for IS x 50m height for 15 x 70m both arms) 106m3. Would need 106m3. Would need to be developed in to be developed in ( conjunction ith con junction with another site, another site. ENVIRONMENTAL CONSI DERATIONS Largely Special Special Uses-Power 20% of 30% of 50% of Rural A 70% of 25% of 70% of Local Uses-Power Station. Station emplacement emplacement emplacement emplacement emplacement in Environ mental emplacement Additional 15.5 ha within Escarpment within Escarpment within Escarpment within Escarpment Escarpment Plans — zoning. within Escarpment required for Protection Zone Protection Zone Protection Zone Protection Zone Protection Zone. Protection Zone emplacement is Remainder Rural A Remainder Rural A Remainder Rural A Remainder Rural A Remainder Rural A zoned Open Space Remainder Rural A Private Recreation Visual Impact -Most visible from Visible from all Visible from the Visible from the Visible from the Visible from the As for Duck Creek Visible from the Visible from north south however directions, however north east. These south east. Would east. Would be north. Would be Site, north Distant views east. Fairly close to these would be these are distant are distant views be highly visible highly visible from a highly visible from from potential a small area of distant views. Can views from across from existing urban from potential small area of potential urban potential urban urbanan areas, be largely screened the lake orat least areas but future urban development potential urban d evlopment areas, development from the F6 1.5km from develoments would areas. development. Adjacent to Illawarra Freeway. potential urban have a much closer Highway. areas. Adjacent to view. F6 Freeway. Flora Site almost entirely Site presently used Largely cleared No flora survey No flora survey As for Mullet Creek No flora survey As for Mullet Creek No flora survey cleared, for ash disposal. except for upper obtained for this obtained for this Site, obtained for this Site, obtained for this No rare or slopes, site but upper site but upper site. Southern site. endangered species Rainforest species slopes are heavily northern slopes are slopes heavily Site largely identified, identified, vegetated, heavily vegetated. vegetated, uncleared. Austromyrtas Lower areas cleared. Lower areas cleared. Rainforest species acmenoides trees Rainforest species identified. identified identified. species considered rare south- of Taree, TABLEBI 00 SUMMARY OF ALTERNATIVE SITES (Contd.) Mt Brown No. 3 Ash Clover Hill Mullet Creek Duck Creek Marshall Mount Marshall Mount Four Oaks Yellow Rock Site Dam Site Site Site Site Creek Site Creek Site Gully Site Creek Site (South) (West) ENVIRONMENTAL CONSIDERATIONS (Contd.) Fauna As for flora. As for flora. Few species of As for Clover Hill. As for Clover Hill. As for Clover Hill. As for Clover Hill. As for Clover Hill. As for Clover Hill. conservation significance known or expected in the area. Clearing of site would resut in a reduction of habitat for some of these species. Water Ouality 1.05 1.0 1.15 )Northarm 1.7 3.0 2.2 5.7 3.1 7.1 Control Ratio of only) catchment area to .45 )Both arms) emplacement) Air Quality Proximity to existing Exposed location Close to potential As for Clover Hill. As for Clover Hill. As for Clover Hill. As for Clover Hill. No major problems As for Four Oaks residential area but is a reasonable urban development would be expected Gully but somewhat would require distance from areas and would as the site is a closer to potential effective dust existing or possible require effective urban area. reasonable distance control measures, future urban dust control from potential development areas. measures. urban development areas. Archaeology No known No aboriginal sites As for Mt Brown. As for Mt Brown. As for Mt Brown. As for Mt Brown. As for Mt Brown. As for Mt Brown. As for Mt Brown. aboriginal relics at remaining. The site this site, is presently used for ash disposal. Heritage No registred sites Site presently used No registered sites No registered sites No registered sites No registered sites No Registered sites No registered sites No registered site affected. for ash disposal. affected. 19th affected. Historic affected, affected, affected, affected. 70% of affected. 70% of Century cottage properties Glen Historic property 60% of 80% of emplacement emplacement "Lindbrook" would Avon and "Hillview" would be emplacement emplacement within National within National be ad)acent to "Benares" would be affected, within National within Natonal Trust Trust Escarpment Trust Escarpment emplacement. affected. 10% of Trust Escarpment Escarpment Conservation area. 20% of 90% of emplacement Conservation area. Conservation area. Conservation area. emplacement emplacement within National within National within National Trust Escarpment Trust Escarpment Trust Escarpment Conservation area. conservation area. Conservation ara. ------S- - - - - -. ------TABLE BI SUMMARY OF ALTERNATIVE SITES (Contd.) Mt Brown No. 3 Ash Clover Hill Mullet Creek Duck Creek Marshall Mount Marshall Mount Four Oaks Yellow Rock Site Dam Site Site Site Site Creek Site Creek Site Gully Site Creek Site (South) (West) ENVIRONMENTAL CONSIDERATIONS (Contd.) Acoustic Development No ma)or difficulties Site would be As for Clover Hill. As for Clover Hill. As for Clover Hill. As for Clover Hill. No difficulty No difficulty height of foreseen. Site is at ad)acent to foreseen. Site is foreseen. Site is 0.5 emplacement least 1.5 km from potential over I km from any km from any would be limited existing or potential residential areas. potential potential because of close residential areas. residential area. proximity to residential area. existing residential area to north. Regional 90% of 100% of 100% of 40% of As for Clover Hill. As for Clover Hill. As for Clover Hill. Not affected. Not affected. Environmental Plan emplacement emplacement emplacement emplacement "Landscape or within this within this within this within this Environmental designated area. designated area but designated area. designated area. Attributes" site already used for ash disposal purposes. '0 I Y.UTA U :i SUMMARY OF ALTERNATIVE SITES (Contd.) Mt Brown No. 3 Ash Clover Hill Mullet Creek Duck Creek Marshall Mount Marshall Mount Four Oaks Yellow Rock Site Dam Site Site Site Site Creek Site Creek Site Gully Site Creek Site (South) (West) PROPERTY CONSIDERATIONS Land requirement Most of required All of the required Portion of the north Very small portion All of the site would As for Duck Creek. As for Duck Creek. As for Duck Creek. As for Duck Creek. (excluding noise site is presently site is presenty arm of this site of the site presently need to be buffer zones) owned by the owned by the presently owned by owned by Huntley acquired. Commission. Commission. Huntley Colliery Colliery Pty. Ltd. Pty. Ltd. Residences directly —2 0 4 1-2 7 (approx). 3 (approx). 4 (approx). I affected by emplacement (excluding noise) Distance to nearest 0.2 km 1.5km 3 km 3km 4km 4km 5km 4.5 km 4km existing residential area Emplacement area Nil Nil 30% North arm 40% 25% 40% Nil Nil Nil within Potential 60% South arm Urban Development Zone (excluding noise buffer) ASH TRANSPORT No additional land No additional land Can utilize Similar to Clover Could utilize about Would require As for Marshall Would require As for Four Oaks required. required. proposed coal Hill but an half of the proposed separate transport Mount Creek South. additional 8km of Gully Site. transport corridor additional I km of transport corridor, corridor for about 5 transport corridor transport corridor Additional 3 km km. for entire distance Would be difficult to and could be would be required. required. integrated with a avoid potential coal haul road urban areas. system. OTHER Requires some Development of Would require Would require Would require Suitable for wet or CONSIDERATIONS relocation of southem arm would particular attention relocation of 132 kV relocation of 330kv dry ash disposal. services, require relocation of to the flood Transmission Line. Transmission Line. 132 kv Transmission protection of Suitable for wet or Line. emplacement toe, dry ash disposal. ------S- - - - - -. ------I I I I. THE ELECTRICITY COlMISSION OF MSW ElS 625 I Tallawarra power project discussion I document II. I I I n THE ELECTRICITY COMMISSION OF NSW EIS 625 Tallawarra power project discussioi document ['s]