Soil and Land Suitability Assessment

Transcription

1 Appendix B Soil and Land Suitability Assessment Environmental Management Plan B May 2014

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3 Colton Coal Project Soil and Land Suitability Assessment Prepared for: Northern Energy Corporation Limited Prepared by: AustralAsian Resource Consultants Pty Ltd March 2010

4 Document History and Status Issue Rev. Issued To Qty Date Reviewed Approved 1 0 NEC 1 13/01/10 A.B. Pearce A.B. Pearce Project Manager: Name of Client : Name of Project: Title of Document: Document Version: Gareth Bramston Northern Energy Corporation Ltd Colton Coal Project Soils and Land Suitability Assessment Final This controlled document is the property of AustralAsian Resource Consultants Pty Ltd and all rights are reserved in respect of it. This document may not be reproduced or disclosed in any manner whatsoever, in whole or in part, without the prior written consent of AustralAsian Resource Consultants Pty Ltd. AustralAsian Resource Consultants Pty Ltd expressly disclaims any responsibility for or liability arising from the use of this document by any third party. Soil and Land Suitability Report i March 2010

5 TABLE OF CONTENTS TABLE OF CONTENTS... II EXECUTIVE SUMMARY... VII 1.0 INTRODUCTION OBJECTIVES TOPOGRAPHY LOCAL GEOLOGY CURRENT LAND USE REGIONAL CLIMATE METHOD LITERATURE REVIEW FIELD SURVEY ANALYSIS CONTAMINATED LANDS THRESHOLDS ACID SULFATE SOILS SOIL CLASSIFICATION RESULTS SOIL TYPES CONTAMINATED LAND THRESHOLDS INVESTIGATION DUNDATHU SOIL MANAGEMENT UNIT CHURCHILL SOIL MANAGEMENT UNIT ACID SULFATE SOIL INVESTIGATION OVERVIEW OF CHEMICAL CHARACTERISTICS SOIL MANAGEMENT ACTIONS TOPSOIL STRIPPING AND REUSE EROSION CONTROL EROSION POTENTIAL EROSION MANAGEMENT LAND SUITABILITY ASSESSMENT AIMS OF THIS ASSESSMENT LAND SUITABILITY CLASSES CURRENT LAND USE PRE-MINING LAND SUITABILITY BEEF CATTLE GRAZING WATER AVAILABILITY NUTRIENT DEFICIENCY SOIL PHYSICAL FACTORS SALINITY ROCKINESS Soil and Land Suitability Report ii March 2010

6 MICRO RELIEF PH EXCHANGEABLE SODIUM PERCENT (10CM) WETNESS WATER EROSION FLOODING SUMMARY OF LAND SUITABILITY CLASSES FOR BEEF CATTLE GRAZING SUMMARY SUITABILITY FOR BEEF CATTLE GRAZING RAINFED BROADACRE CROPPING WATER AVAILABILITY NUTRIENT DEFICIENCY SOIL PHYSICAL FACTORS SOIL WORKABILITY SALINITY ROCKINESS MICRO RELIEF WETNESS TOPOGRAPHY WATER EROSION FLOODING SUMMARY OF LAND SUITABILITY CLASSES FOR RAINFED BROADACRE CROPPING SUMMARY SUITABILITY OF LAND FOR RAINFED BROADACRE CROPPING CONSERVATION CONCLUSION AND RECOMMENDATIONS REFERENCES LIST OF FIGURES Figure 1: Regional Location of the Colton Coal Project Site Figure 2: Site Specific Geology (1:250,000) Figure 3: Maryborough Temperature and Rainfall Data Figure 4: Wind Roses Measured at Maryborough Figure 5: Colton Coal Project Area and Primary Soil Sampling Sites Figure 6: Soil Management Units of the Project Area Figure 7: Areas of the Colton Project below 20m AHD Figure 8: Acid Sulfate Soils - Maryborough Area (NRM 2002) Figure 9: Pre-Mining Land Suitability Beef Cattle Grazing Figure 10: Pre-Mining Land Suitability Rainfed Broadacre Cropping Figure 11: Pre-Mining Land Suitability Conservation Soil and Land Suitability Report iii March 2010

7 LIST OF TABLES Table 1: Contaminated Lands Health and Environmental Investigation Thresholds Table 2: Australian Soil Classification (Isbell 1996) Table 3: Dundathu Contaminant Levels Table 4: Churchill Contaminant Levels Table 5: Typical Chemical Analysis of the Dundathu Soil Management Unit Table 6: Typical Chemical Analysis of the Churchill Soil Management Unit Table 7: Land Suitability Classes for Beef Cattle Grazing Based on PAWC Table 8: Land Suitability Classes for Beef Cattle Grazing Based on Nutrient Status Table 9: Land Suitability Classes for Beef Cattle Grazing Based on Soil Physical Factors Table 10: Land Suitability Classes for Beef Cattle Grazing Based on Salinity Table 11: Land Suitability Classes for Beef Cattle Grazing Based on Rockiness Table 12: Land Suitability Classes for Beef Cattle Grazing Based on Micro relief Table 13: Land Suitability Classes for Beef Cattle Grazing Based on ph Table 14: Land Suitability Classes for Beef Cattle Grazing Based on ESP excl. Al Table 15: Land Suitability Classes for Beef Cattle Grazing Based on Wetness Table 16: Land Suitability Classes for Beef Cattle Grazing Based on Water Erosion Table 17: Land Suitability Classes for Beef Cattle Grazing Based on Flooding Table 18: Land Suitability Limitations for Beef Cattle Grazing Table 19: Pre-mining Suitability for Beef Cattle Grazing Table 20: Land Suitability Classes for Rainfed Broadacre Cropping Based on PAWC Table 21: Land Suitability Classes for Rainfed Broadacre Cropping Based on Nutrient Status Table 22: Land Suitability Classes for Rainfed Broadacre Cropping Based on Physical Factors.. 40 Table 23: Land Suitability Classes for Rainfed Broadacre Cropping Based on Soil Workability Table 24: Land Suitability Classes for Rainfed Broadacre Cropping Based on Salinity Table 25: Land Suitability Classes for Rainfed Broadacre Cropping Based on Rockiness Table 26: Land Suitability Classes for Rainfed Broadacre Cropping Based on Micro relief Table 27: Land Suitability Classes for Rainfed Broadacre Cropping Based on Wetness Table 28: Land Suitability Classes for Rainfed Broadacre Cropping Based on Topography Table 29: Land Suitability Classes for Rainfed Broadacre Cropping Based on Water Erosion Table 30: Land Suitability Classes for Rainfed Broadacre Cropping Based on Flooding Table 31: Land Suitability Limitations for Rainfed Broadacre Cropping Table 32: Pre-mining Suitability for Rainfed Broadacre Cropping Table 33: Vegetation Communities of the Project site Table 34: Pre-Mining Land Use Suitability LIST OF ABBREVIATIONS % percent ~ approximately < less than C degrees Celsius AARC AHD AustralAsian Resource Consultants Australian Height Datum Soil and Land Suitability Report iv March 2010

8 ARD ASS CEC cm CSIRO Cth DEW DME DNRW EC EIS EPBC Act ESP g GPS ha hr km m Meq mg MLA mm NATA NEC PAWC ph Acid Rock Drainage Acid Sulphate Soil Cation Exchange Capacity centimetre Commonwealth Scientific and Industrial Research Organisation Commonwealth Department of Environment and Water Department of Minerals and Energy Department of Natural Resources and Water Electrical Conductivity Environmental Impact Statement Environmental Protection and Biodiversity Conservation Act 1998 (Cth) Exchangeable Sodium Percentage gram Global Positioning System hectare hour kilometres metres milliequivalents milligrams Mining Lease Application millimetre National Association of Testing Authorities Northern Energy Corporation Ltd. Plant Available Water Capacity power of Hydrogen Soil and Land Suitability Report v March 2010

9 ppm QEPA RE SLSA SPP Spp. the Project the Proponent parts per million Queensland Environmental Protection Agency Regional Ecosystem Soil and Land Suitability Assessment State Planning Policy species Colton Coal Project Northern Energy Corporation Ltd. Soil and Land Suitability Report vi March 2010

10 EXECUTIVE SUMMARY Introduction AustralAsian Resource Consultants Pty Ltd (AARC) was commissioned by Northern Energy Corporation (NEC) Limited to undertake a Soil and Land Suitability Assessment (SLSA) for the proposed Colton Coal Project. The objectives of the Soil and Land Suitability Assessment were to: Determine the pre-disturbance land suitability of the Project site; Collect baseline data for soils on the Project site and determine management strategies for the Project s land resources; Identify physical and chemical properties of the soil that will influence rehabilitation success such as erosion potential and soil nutrient status; Investigate the existing acidity of surface soils on the Project site and the potential for the disturbance of Acid Sulphate Soils; Investigate the concentrations of certain elements (such as metals) occurring naturally in the soil on the Project site, and determine whether or not they exceed those permitted under the State s contaminated land regulations; and Provide information on the lateral and vertical distribution of soils suitable for rehabilitation to assist in the development of soil stripping and management guidelines for the proposed disturbance areas. Methodology An initial field survey was undertaken over a period of 7 days, from the 11 th to the 17 th of August An additional field survey was conducted over a period of 4 days, from the 19 th to the 22 nd of September In total, 85 survey sites were assessed within the confines of the Project boundary. At each sampling site, a square mouth post hole shovel with a blade width of 195 mm was used to excavate a hole. A 500 g sample of soil was taken at four depths (where possible) throughout the profile, generally: 0-10 cm; cm; cm; and, cm. Each sample was sealed in a clean plastic clip-lock bag, and the bags labelled with the sample site number and depth of sampling. At the completion of the field survey, a selection of soil samples were packaged for transportation to a National Association of Testing Authorities (NATA) registered laboratory for chemical and physical analysis. Soil and Land Suitability Report vii March 2010

11 Results The current land status of the Project Site is unallocated state land. Based on field and laboratory assessment, two soil types were observed to occur. These have been classified as two soil management units which are described below. Soil Type Soil Type 1: Dundathu Soil Management Unit Soil Type 2: Churchill Soil Management Unit Brief Description Grey to brownish grey through the upper horizon diffusing to light yellowish brown to pale brown in the lower solum. Moderately acidic throughout the solum, with a distinctively high total nitrogen content and fine sandy clay loam texture. The soil is considered sodic with a poor structure. Greyish brown fine sandy loam diffusing to a very pale brown, sometimes light grey or white, fine sandy loam in the lower solum. The soil is moderately acidic and nutrient deficient. The soil is considered sodic, increasing to strongly sodic in places, with a poor structure. The levels of trace metals recorded for both soil types fall well below the contaminated lands thresholds in Appendix 9.1 of the Draft Guidelines for the Assessment and Management of Contaminated Land in Queensland. In accordance with the State Planning Policy 2/02 Planning and Managing Development Involving Acid Sulphate Soils, the risk of disturbance to potentially Acid Sulfate Soils is considered low given the majority of the site has a natural ground level greater than 20 m AHD and in areas below 20 m AHD disturbance activities are limited to shallow surface earthworks for mine infrastructure with no disturbance of material below 5 m AHD. Additionally, Queensland Government mapping shows that the Project area is considered to have a low probability of ASS occurrence. The pre-mining land use suitability for these two soil types is summarised below: Soil Type Beef Cattle Grazing Pre-Mining Land Use Suitability Broadacre Cropping 1: Dundathu : Churchill Conservation Limitations Area Severe to Extreme Limitations regarding Nutrient Deficiency, Sodicity and Soil and Surface Water Hydrology Severe Limitations regarding Nutrient Deficiency, Sodicity and Soil and Surface Water Hydrology ha ha Management Actions Topsoil should be stripped and stockpiled for later use in rehabilitation works. Topsoil should be stripped to the following depths: Dundathu Soil Management Unit topsoil should be stripped to 10cm where practicable, Churchill Soil Management Unit topsoil should be stripped to 10cm where practicable. Soil and Land Suitability Report viii March 2010

12 The topsoil stockpiles should be approximately 1-2m in height and should be placed away from roads, machinery, transport corridors, and stock grazing areas. The stockpiles may need to be ripped and seeded with a quick establishment pasture, to limit erosion, and maintain a viable seed bank if the period of stockpiling is greater than 1 growing season or 6 months. Topsoil stockpiles need to be away from any run-off areas and sheltered from the prevailing winds. When used in rehabilitation the soil will require phosphate based fertiliser (at approximately 100kg/ha) as the topsoil on the Project site is low in fertility. Both soil management units identified on the Project area are considered moderately to strongly sodic. This sodicity increases gradually with depth, and means that the soils of the site are chemically predisposed to erosion. The sodic nature of these soils, coupled with a low Calcium/Magnesium Ratio results in a high erosion potential if disturbed. As such, management options suggested for the mitigation of soil erosion include: Only the minimum land required to be cleared for the safe operation of the Project at any one time should be conducted; Land to be cleared should be surveyed and marked out prior to clearing and signed off by an appropriate person to ensure no significant areas are inadvertently disturbed; The disturbed area of the Project should be rehabilitated progressively where possible; Mine rehabilitation should aim to return the land to the pre-mining land suitabilities; Sediment dams or stormwater dams should be installed for all cleared areas and areas of mine or processing infrastructure; Stripping of topsoil material should be conducted prior to any construction or land clearing for later use in land rehabilitation. Large trees and shrubs should be cleared first and stockpiled separately to the topsoil. Topsoil should be stripped to the depth nominated in Section for the different soil types and stockpiled in piles no more than 2 m high. Ripping and seeding topsoil stockpiles may be required if the topsoil is to be stockpiled for several years; Regular monitoring of suspended solids in creeks downstream of disturbed areas to monitor the effectiveness of erosion reduction measures. Conclusion After review of soil and land suitability data, it has been determined that there are no significant barriers, regarding land use and soil characteristics, to the development of the Colton Coal Project. Soil and Land Suitability Report ix March 2010

13 1.0 INTRODUCTION AustralAsian Resource Consultants Pty Ltd (AARC) was commissioned by Northern Energy Corporation Ltd (NEC) to undertake a Soil and Land Suitability Assessment (SLSA) for the proposed Colton Coal Project (herein referred to as the Project). The Project Site is located in southern Queensland, approximately 15 kilometres (km) north of Maryborough. The proposed site is approximately 20 km inland of the Port of Maryborough, and 230 km north of Brisbane, as shown in Figure 1. Access to the Project Site is via the Churchill Mine Road which connects to the Maryborough Hervey Bay Road. 1.1 OBJECTIVES The objectives of the SLSA were to: Determine the pre-disturbance land suitability of the Project site; Collect baseline data for soils on the Project site and determine management strategies for the Project s land resources; Identify physical and chemical properties of the soil that will influence rehabilitation success such as erosion potential and soil nutrient status; Investigate the existing acidity of surface soils on the Project site and the potential for the disturbance of Acid Sulphate Soils; Investigate the concentrations of certain elements (such as metals) occurring naturally in the soil on the Project site, and determine whether or not they exceed those permitted under the State s contaminated land regulations; and Provide information on the lateral and vertical distribution of soils suitable for rehabilitation to assist in the development of soil stripping and management guidelines for the proposed disturbance areas. 1.2 TOPOGRAPHY The Maryborough prospect is located on within the Mary River Drainage Basin, on gently undulating coastal low land plains. Sandy soils occur uniformly throughout the lowland area of the site with evidence of higher concentrations of organic matter in the more elevated areas. The western side of the site is crossed by several ephemeral drainage lines. Flows in these waterways are restricted to during heavy rainfall events. Soil and Land Suitability Report 10 March 2010

14 Figure 1: Regional Location of the Colton Coal Project Site 1.3 LOCAL GEOLOGY The Colton Coal Project proposes open cut coal mining of the Burrum Coal Measures in the Maryborough Basin. A 1.5 Million tonne (Mt) coking coal resource has been estimated within multiple thinly bedded seams. The region is based on marine and alluvial sediments of the Maryborough Basin (Sattler and Williams 1999). Geological mapping of the area at a scale of 1: describes two predominant categories on the Project Site (Figure 2): Mesozoic labile sandstone, mudstone, siltstone, shale and conglomerate, indicated by Kb in Figure 2. Cainozoic duricrusted old land surface with ferricrete, silcrete and indurated palaeosoils at the top of a deep weathering profile, indicted by Td/Kb in Figure 2. In addition, Quaternary alluvial sediments are present in narrow corridors following unnamed waterways on the site (not visible in 1: scale mapping). Soil and Land Suitability Report 11 March 2010

15 Figure 2: Site Specific Geology (1:250,000) Developed from: Australian 1: Geological Series, Maryborough Queensland Kb - Mesozoic, early Cretaceous (Burrum Coal Measures): Feldspatholithic labile sandstone, siltstone, mudstone, shale, conglomerate, glauconitic sandstone. Td/Kb - Cainozoic, Olgiocene to Miocene: Duricrusted old land surface; Ferricrete, silcrete and indurated palaeosoils at the top of a deep weathering profile 1.4 CURRENT LAND USE The MLA is situated on unallocated state land. Recent land use of the Project Site includes selective logging and coal exploration. Associated infrastructure on the site includes access tracks and clearing for drill pads. Historic mining has been undertaken in the region and open shafts are evident nearby the site. 1.5 REGIONAL CLIMATE The following information provides a climatic description of the Project region, compiled using climatic data from the Australian Bureau of Meteorology (BOM). Data has been sourced from the BOM weather monitoring station located in Maryborough ( E, S), approximately 15 kilometres south of the Colton Coal Project area. The BOM Maryborough weather monitoring station commenced collecting data in 1870 and is still operational. Information from the Bureau of Meteorology indicates that the average annual rainfall for the region (based on data for the Maryborough weather station) is approximately 1152 millimetres (mm). Rainfall occurs year round, with the driest period of the year between the months of July and September Soil and Land Suitability Report 12 March 2010

16 (average 45.3 mm per month) and the wettest period between December and March (average mm per month). The coldest period of the year occurs in July (average minimum 8.6 degrees Celsius (ºC), average maximum 22.0 ºC) and the warmest month of the year is January (average minimum 20.6 ºC, average maximum 30.7 ºC). Figure 3: Maryborough Temperature and Rainfall Data Light winds between 10 and 20 kilometres per hour (km/hr) from a south-easterly direction are dominant in the region. Wind roses for the region as measured at the Maryborough weather monitoring station are presented in Figure 4. Soil and Land Suitability Report 13 March 2010

17 Figure 4: Wind Roses Measured at Maryborough Soil and Land Suitability Report 14 March 2010

18 2.0 METHOD 2.1 LITERATURE REVIEW A review of the Department of Natural Resources and Water database indicates that no detailed mapping of soils and land suitability for the Colton Coal Project area has been carried out. The CSIRO s land system map at a scale of 1:1,150,000 covers the site; however, this scale does not provide sufficient detail to compare with this investigation. 2.2 FIELD SURVEY Field survey methods consisted of both primary sampling as well as secondary visual assessments. Primary sampling involved the extraction of a soil sample at a predetermined intensity along a sampling grid. Secondary visual assessments were conducted continuously across the study area while traversing the primary sample grid. Survey and sampling strategies were developed in reference to the Technical Guidelines for the Environmental Management of Exploration and Mining in Queensland Land Suitability Assessment Techniques (DME 1995) and designed to provide a broad coverage of the Project area. The Technical Guidelines provide a systematic framework to ensure adequate coverage of changes in topography and geology. A field survey was undertaken over a period of 7 days, from the 11th to the 17th of August Primary sampling was conducted at a total of 70 locations. An additional field survey was conducted over a period of 4 days, from the 19th to the 22nd of September During the subsequent survey, primary sampling was conducted at a total of 22 locations. In total, 85 primary sampling sites fell within the confines of the revised Project boundary. These points are mapped in Figure 5. The location of each site was recorded using a Global Positioning System (GPS). Survey and sampling strategies were developed in reference to the Technical Guidelines for the Environmental Management of Exploration and Mining in Queensland Land Suitability Assessment Techniques (DME 1995) and designed to provide a broad coverage of the Project area. The Technical Guidelines provide a systematic framework to ensure adequate coverage of changes in topography and geology. At each sampling site, a square mouth post hole shovel with a blade width of 195 mm was used to excavate a hole. A 500 g sample of soil was taken at four depths (where possible) throughout the profile, generally: 0-10 cm; cm; cm; and, cm. Each sample was sealed in a clean plastic zip-lock bag and the bags labelled with the sample site number and depth of sampling. At the completion of the field survey, bagged soil samples were grouped together into similar soil types based on field observation, soil physical characteristics and the topographical and vegetation characteristics of the survey site. This arrangement, coupled with a site map outlining soil sampling locations, was used to select several representative samples of each Soil and Land Suitability Report 15 March 2010

19 soil type for further analysis of their chemical and physical properties. The selected samples were then packaged for transportation to a National Association of Testing Authorities (NATA) registered laboratory for chemical and physical analysis. 2.3 ANALYSIS All samples were analysed for the following parameters: ph (water); ph (CaCl 2 ); Electrical Conductivity; Chloride; Nitrate Nitrogen; Total Nitrogen; Phosphorus; Exchangeable cations (Ca, Mg, Na, K, Al); Trace elements (Cu, Zn, Mn, Fe) Carbonate; Sulphate Sulphur; Organic Carbon; and Colour and texture. Soil analysis also included calculation of the following parameters: Cation Exchange Capacity (CEC) Calcium/Magnesium Ratio Exchangeable Sodium Percentage (ESP) The soil analysis was conducted by the NATA registered SGS Agritech Toowoomba laboratory. 2.4 CONTAMINATED LANDS THRESHOLDS Several parameters were also assessed in comparison to Appendix 9.1 of the Draft Guidelines for the Assessment and Management of Contaminated Lands in Queensland (EPA 1998). These parameters, and the associated thresholds for further investigation, are listed in Table 1. Soil and Land Suitability Report 16 March 2010

20 Table 1: Contaminated Lands Health and Environmental Investigation Thresholds Parameter Environmental Investigation Level Health based Investigation Level (Commercial and Industrial land use) Copper 60 mg/kg 5000 mg/kg Zinc 200 mg/kg mg/kg Manganese 500 mg/kg mg/kg 2.5 ACID SULFATE SOILS State Planning Policy 2/02 Planning and Managing Development Involving Acid Sulphate Soils (DIP 2002) sets out the State s interests concerning development involving acid sulphate soils in low-lying coastal areas. This State Planning Policy (SPP) replaced the temporary SPP 1/00: Planning and management of coastal development involving acid sulphate soils in The policy applies only to certain types of development assessments in a strict list of local government areas outlined in Annex 1. The Project was assessed in comparison to the conditions outlined in the policy. An assessment was made into the level of risk associated with disturbance of potentially acid sulphate soils given the proposed mining development. 2.6 SOIL CLASSIFICATION Soil classification was undertaken using the methodology specified in the The Australian Soil Classification Revised Edition (Isbell 1996). Based on the characteristics of the soil profile, this classification methodology lists 14 orders of soils. Table 2 provides a list of the soil orders and a brief description of each. Table 2: Australian Soil Classification (Isbell 1996). Soil Order Description Anthroposols Calcarosols Chromosols Dermosols Soils formed by humans. Formed by the modification or mixing of the original soil, or the creation of new soil parent material as a result of human activities. Identified by the presence of artefacts in the profile or knowledge that the soils or parent materials have been made or altered by human action. Soils dominated by carbonate. Soils which feature the presence of variable amounts and forms of identifiable pedogenic calcium carbonate. Limitations include shallow depth, low water retention due to hard carbonate content and wind erosion of the sandier types. High salinity, alkalinity and sodicity may also be a problem. Soil fertility deficiencies are widespread. Neutral to alkaline soils with sharp increase in texture. Soils with an abrupt increase in clay; or, texture contrast. Mildly acidic B horizon, and non-sodic in its upper 0.2m. May have impeded internal drainage, and long periods of agriculture often degrade soil structure. Structured B horizons and minor changes in texture. Lack texture contrast, are not calcareous, and have moderately to strongly structured lower B horizons. Moderately deep and relatively well-drained soils of wetter areas in eastern Australia. May be strongly acid in the high rainfall areas or highly alkaline if they contain calcareous subsoils. Soil and Land Suitability Report 17 March 2010

21 Soil Order Description Ferrosols Hydrosols Kandosols High iron levels and minor changes in texture. Iron rich soils. High in free-iron oxide and clay contents. Often feature strongly developed polyhedral peds in B horizons. In high rainfall zones they may be very deep and well drained. Wet soils. Seasonally or permanently wet soils, which are saturated for 2-3 months or more due to site or tidal influence. Distribution is often limited to wet drainage depressions, low lying narrow coastal plains and seepage areas on lower slopes. Strongly weathered earths with minor changes in texture. Structureless soils. Mostly well-drained, permeable soils, although some Yellow and most Grey Kandosols have impeded subsoil drainage. Most have low fertility and land use is restricted to grazing of native pastures. Kurosols Acid soils with sharp increases in texture. Acidic soils with a clear or abrupt textural B horizon. Often feature a strongly bleached lower A horizon, and mottled B horizon. Organosols Podosols Rudosols Organic soils. Dominated by organic materials of specified thickness and organic carbon content which varies according to clay content. Occur in wet landscapes and many have long been known as peats. Soils with accumulations of organic matter, iron and aluminium. Feature B horizons dominated by the accumulation of compounds of organic matter and aluminium, with or without iron. Usually sand textured to depth. B horizons can be very deep, as far as 20m in giant forms. Often have conspicuously bleached lower A horizon. Most are very permeable unless indurated pans are present, and site drainage may also cause periods of saturation. Minimally developed soils. Soils which consist of materials that have not been greatly affected by pedological processes. Widespread soils with few commercial land uses. Tenosols Sodosols Vertosols Slightly developed soils. Only weak pedological development (with the exception of the A horizon). Soils with low water retention, low fertility. Occur generally in low and erratic rainfall areas. Alkaline and sodic soils with sharp increases in texture. Key feature is the presence of a clear or abrupt textural B horizon, the upper 0.2m of which has an ESP of 6 or greater and is not strongly acidic (ph greater than 5.5). Cracking clays. Shrink and swell soils with a clay-field texture containing 35% or more clay throughout the solum. When dry, these soils often crack to considerable depth.. Problems of water infiltration are usually related to tillage practices and adverse soil physical conditions at least partly inducted by high sodium in the upper part of many profiles. Soil and Land Suitability Report 18 March 2010

22 Figure 5: Colton Coal Project Area and Primary Soil Sampling Sites Soil and Land Suitability Assessment 19 March 2010

23 3.0 RESULTS 3.1 SOIL TYPES Based on field and laboratory assessment, two soil types have been identified on the Project site. These have been mapped as two distinct mapping units (refer to Figure 6 for a plan of the distribution of these mapping units). The different units consist of: Soil Type 1: Grey to brownish grey through the upper horizon diffusing to light yellowish brown to pale brown in the lower solum. Moderately acidic throughout the solum, with a distinctively high total nitrogen content and fine sandy clay loam texture. The soil is considered sodic with a poor structure. Soil Type 2: Greyish brown fine sandy loam diffusing to a very pale brown, sometimes light grey or white, fine sandy loam in the lower solum. The soil is moderately acidic and nutrient deficient. The soil is considered sodic, increasing to strongly sodic in places, with a poor structure. Each of these soil types is described below. 1: Grey to brownish grey through the upper horizon diffusing to light yellowish brown to pale brown in the lower solum. Moderately acidic throughout the solum, with a distinctively high total nitrogen content and fine sandy clay loam texture. The soil is considered sodic with a poor structure. This soil type covers approximately hectares (ha) of the Colton Coal Project Site. Occurring exclusively throughout the lower lying drainage areas, this soil type supports open Melaleuca woodland communities, dominated by Melaleuca quinquenervia and Melaleuca viridiflora with understory ground cover of Grass Tree, Kangaroo Grass, Drosera peltata, Slender Rice Flower and Swamp Banksia. The topography is generally of low relief with slopes tending to be less than 2%. A defining characteristic of this soil type is distinct light yellowish hues in the lower horizon and slightly higher clay and nitrogen content, than the adjacent soil type. Field observations also indicate that this soil has significant gravel content at a depth of approximately cm. However, it is highly likely that the soil extends further than the 90cm confirmed during the survey and this rock is not considered parent material. This soil has a moderately acidic ph, and is sodic. A single grain structure and low Calcium Magnesium ratio predispose this soil type to be sticky in wet conditions and relatively firm when dry. The soil meets the requirements of a Semiaquic Podosol when compared with the Australian Soil Classification (Isbell et al. 1996). This soil type constitutes the Dundathu soil management unit. 2: Greyish brown fine sandy loam diffusing to a very pale brown, sometimes light grey or white, fine sandy loam in the lower solum. The soil is moderately acidic and nutrient deficient. The soil is considered sodic, increasing to strongly sodic in places, with a poor structure. This soil type covers ha of the Colton Coal Project Site. Occurring on the slightly more elevated alluvial plains on the Project site, this soil type is found on generally flat relief (with slopes less than 2%) and covers a majority of the site. This soil type supports mixed Eucalypt woodland species dominated by Pink Bloodwood, White Mahogany, with Blue Gum, Queensland Peppermint and Spotted Gum occasionally present. Ground cover dominated by Grass Tree as well as Fimbristylis sp., Rhynchospora heterochaeta, Kangaroo Grass, Guinea Flower and Swamp Soil and Land Suitability Assessment 20 March 2010

24 Banksia. Evidence suggests that the depth of the soil extends further than the cm confirmed during the survey. This soil unit is typified by a fine sandy loam texture, greyish brown in the upper layers diffusing to pale brown at depth. The soil is of loose consistence with a single grain structure. This single grain structure and relatively low Calcium/Magnesium ratio predispose the soil to be sticky in wet conditions and relatively firm when dry. It must be noted that Calcium does dominate Magnesium in this ratio, however, not to the extent that would improve soil structure. The texture remains consistent throughout the profile and the soil is sandier than the adjacent soil type. This soil is moderately acidic and is considered sodic increasing to strongly sodic in several areas. The characteristics of this soil constitute an Aeric Podosol when compared with the Australian Soil Classification (Isbell et al. 1996). This soil type constitutes the Churchill soil management unit. Soil and Land Suitability Assessment 21 March 2010

25 Figure 6: Soil Management Units of the Project Area Soil and Land Suitability Assessment 22 March 2010

26 3.2 CONTAMINATED LAND THRESHOLDS INVESTIGATION As part of the soil assessment, the levels of various trace metals were tested in order to determine the naturally occurring background levels. This section compares the concentration of metals found on the project site with the Investigation Thresholds for Contamination in Soils from the Draft Guidelines for the Assessment and Management of Contaminated Land in Queensland (EPA 1998). This comparison will highlight any naturally high levels of metals that occur prior to the commencement of mining operations Dundathu Soil Management Unit The Dundathu Soil Management Unit generally has low levels of recognised contaminants, as seen in Table 3, and does not exceed any of the threshold levels. Table 3: Dundathu Contaminant Levels Parameter Environmental Investigation Level (mg/kg) Health based Investigation Level (Commercial and Industrial land use) (mg/kg) Average Result (mg/kg) Copper <0.1 Zinc Manganese * Taken from Appendix 9.1 Investigation Thresholds for Contaminants in Soils (EPA 1998) Churchill Soil Management Unit The Churchill Soil Management Unit generally has low levels of recognised contaminants, as seen in Table 4, and does not exceed any of the threshold levels. Table 4: Churchill Contaminant Levels Parameter Environmental Investigation Level (mg/kg) Health based Investigation Level (Commercial and Industrial land use) (mg/kg) Average Result (mg/kg) Copper <0.1 Zinc Manganese * Taken from Appendix 9.1 Investigation Thresholds for Contaminants in Soils (EPA 1998) 3.3 ACID SULFATE SOIL INVESTIGATION Coastal areas such as the Maryborough local government area are considered to be at risk of potential Acid Sulphate Soil (ASS) according to Annex 1 of the State Planning Policy 2/02 Planning and Managing Development Involving Acid Sulphate Soils (DIP 2002). However, both the policy and ASS risk applies to land, soil and sediment at or below 5m Australian Height Datum (AHD) where the natural ground level is less than 20 m AHD. Only a small area of the Colton Project MLA has a natural ground level below 20 m AHD (Figure 7). Disturbance activities within this area are Soil and Land Suitability Assessment 23 March 2010

27 limited to shallow surface earthworks for mine infrastructure and access roads with no disturbance of material below 5 m AHD. Given that within the highlighted areas excavation works will not extend to a depth of 5 m AHD the SPP 2/02 does not apply to this Project and disturbance to potential ASS soils is not considered a risk. Figure 7: Areas of the Colton Project below 20m AHD In addition, Queensland Government mapping shows that the Colton Project area is considered to have a low probability of ASS occurrence (Figure 8) (NRM 2002). The acid forming potential of overburden, interburden, floor rock and process wastes found within and surrounding the approximate pit area (Figure 7) is assessed separately within the Acid Rock Drainage (ARD) Assessment Report (Environmental Geochemistry International Pty Ltd 2009). Soil and Land Suitability Assessment 24 March 2010

28 Figure 8: Acid Sulfate Soils - Maryborough Area (NRM 2002) 3.4 OVERVIEW OF CHEMICAL CHARACTERISTICS Laboratory analysis of several soil parameters indicates that the surface soils at the site are generally of very low to low fertility. Soils of the Colton Coal Project area are typically sodic and moderately acidic. This intermediate level of sodicity predisposes the soil to dispersion, but given the topography of the site, under undisturbed conditions erosion is not of significant concern. The calcium/magnesium ratio of these soils is relatively low, generally 1.5 or less, resulting in a soil that is sticky in wet conditions and relatively firm when dry. A summary of the statistical analysis of various chemical and physical properties is presented in Tables 5 and 6. Soil and Land Suitability Assessment 25 March 2010

29 Table 5: Typical Chemical Analysis of the Dundathu Soil Management Unit Analyte Units 0-10 cm 20-30cm cm cm Average SD Median Average SD Median Average SD Median Average SD Median Average Nitrogen mg/kg Total Kjeldahl Nitrogen mg/kg Acidity ph - Water ph - CaCl Potassium mg/kg Major Elements Nitrate Nitrogen mg/kg <1 <2 1.2 <1 < <1 < <1.5 <1.5 Phosphorus - Colwell mg/kg <1 < <1 < <1 < <1.5 <1.5 Aluminium mg/kg Calcium mg/kg Secondary Elements Magnesium mg/kg Calcium Carbonate % <0.5 < <0.8 < <1 < <0.5 <0.5 Sulphur - KCl mg/kg Copper mg/kg <0.1 < <0.1 < <0.1 < <0.1 <0.1 Trace elements Iron mg/kg Manganese mg/kg <1 < <1 < <1 < <1 <1 Zinc mg/kg Organic Matter Organic Carbon % Electrical Conductivity ds/m Salinity Sodium mg/kg Chloride mg/kg Calcium/Magnesium Ratio Cation Exchange Capacity meq/100g Exchangeable Aluminium meq/100g Exchangeable Aluminium % Exchangeable Calcium meq/100g Exchangeable Cations Exchangeable Calcium % Exchangeable Magnesium meq/100g Exchangeable Magnesium % Exchangeable Potassium meq/100g Exchangeable Potassium % Exchangeable Sodium meq/100g Exchangeable Sodium (ESP) % Soil and Land Suitability Assessment 26 March 2010

30 Table 6: Typical Chemical Analysis of the Churchill Soil Management Unit Analyte Units 0-10 cm 20-30cm cm cm Average SD Median Average SD Median Average SD Median Average SD Median Average Nitrogen mg/kg Total Kjeldahl Nitrogen mg/kg Acidity ph - Water ph - CaCl Potassium mg/kg Major Elements Nitrate Nitrogen mg/kg <1 < <1 < <1 <2 0.5 <1.5 <1.5 Phosphorus - Colwell mg/kg <1 < <1 < <1 <1 0.0 <1 <1 Aluminium mg/kg Calcium mg/kg Secondary Elements Magnesium mg/kg Calcium Carbonate % <0.1 < <0.1 < <0.1 < <0.1 <0.4 Sulphur - KCl mg/kg Copper mg/kg <0.1 < <0.1 < <0.1 < <0.1 <0.1 Trace elements Iron mg/kg Manganese mg/kg <1 < <1 < <1 < <1 <1.3 Zinc mg/kg Organic Matter Organic Carbon % <0.8 <1 0.3 <0.5 < <0.3 < <0.3 <0.3 Electrical Conductivity ds/m Salinity Sodium mg/kg Chloride mg/kg Calcium/Magnesium Ratio Cation Exchange Capacity meq/100g Exchangeable Aluminium meq/100g Exchangeable Aluminium % Exchangeable Calcium meq/100g Exchangeable Cations Exchangeable Calcium % Exchangeable Magnesium meq/100g Exchangeable Magnesium % Exchangeable Potassium meq/100g Exchangeable Potassium % Exchangeable Sodium meq/100g Exchangeable Sodium (ESP) % Soil and Land Suitability Assessment 27 March 2010

31 3.5 SOIL MANAGEMENT ACTIONS Topsoil Stripping and Reuse Topsoil should be stripped and stockpiled for later use in rehabilitation works. Topsoil should be stripped to the following depths: Dundathu Soil Management Unit topsoil should be stripped to 20cm where practicable, Churchill Soil Management Unit topsoil should be stripped to 20cm where practicable. These depths have been determined with consideration to the levels of exchangeable sodium within the soil. Given both soil types display elevated levels of exchangeable sodium and are therefore predisposed to erosion, particular care should be taken in the management of topsoil stockpiles. The topsoil stockpiles should be no greater than 2 m in height and should be placed away from roads, machinery, transport corridors, and stock grazing areas. The stockpiles may need to be ripped and seeded with a quick establishment pasture, to limit erosion, and maintain a viable seed bank if the period of stockpiling is greater than 1 growing season or 6 months. Topsoil stockpiles should be removed from any run-off areas. When used in rehabilitation, the soil would benefit form the application of phosphate based fertiliser (at approximately 100kg/ha) as the topsoil on the Project site is low in fertility Erosion Control Erosion Potential Both the soil management units identified on the Project area are considered moderately to strongly sodic. This sodicity increases gradually with depth, and means that the soils of the site are chemically predisposed to erosion. The sodic nature of these soils, coupled with a low Calcium/Magnesium Ratio (as seen in Tables 5 and 6), results in a high erosion potential if disturbed Erosion Management Management options for the mitigation of soil erosion include: Only the minimum land required to be cleared for the safe operation of the Project at any one time should be conducted; Land to be cleared should be surveyed and marked out prior to clearing and signed off by an appropriate person to ensure no significant areas are inadvertently disturbed; The disturbed area of the Project should be rehabilitated progressively where possible; Mine rehabilitation should aim to return the land to the pre-mining land suitabilities; Sediment dams or stormwater dams should be installed for all cleared areas and areas of mine or processing infrastructure; Soil and Land Suitability Assessment 28 March 2010

32 Stripping of topsoil material should be conducted prior to any construction or land clearing for later use in land rehabilitation. Large trees and shrubs should be cleared first and stockpiled separately to the topsoil. Topsoil should be stripped to the depth nominated in Section for the different soil types and stockpiled in piles no more than 2 m high. Ripping and seeding topsoil stockpiles may be required if the topsoil is to be stockpiled for several years; Regular monitoring of suspended solids in creeks downstream of disturbed areas to monitor the effectiveness of erosion reduction measures. Soil and Land Suitability Assessment 29 March 2010

33 4.0 LAND SUITABILITY ASSESSMENT 4.1 AIMS OF THIS ASSESSMENT This Land Suitability Assessment aims to evaluate the land suitability of the Project Site for a variety of uses prior to mining. This was evaluated using the Planning Guideline - The Identification of Good Quality Agricultural Land (DIP 1993) and the Department of Minerals and Energy Land Suitability Assessment Techniques Guideline (DME 1995). 4.2 LAND SUITABILITY CLASSES An interpretation of data collected on the physical, chemical and nutritional characteristics of the soil is made to rank the land according to a five-class system that applies to grazing, rainfed cropping and conservation. The classes are described as: Class 1 Class 2 Class 3 Class 4 Class 5 Suitable land with negligible limitations which is highly productive requiring only simple management practises to maintain economic production. Suitable land with minor limitations which either reduce production or require more than the simple management practices of Class 1 land to maintain economic production. Suitable land with moderate limitations which either further lower production or require more than those management practices of Class 2 land to maintain economic production. Marginal land with severe limitations which make it doubtful whether the inputs required to achieve and maintain production outweigh the benefits in the long term (presently considered unsuitable due to the uncertainty of the land to achieve sustained economic production). Unsuitable land with extreme limitations that preclude its use for the proposed purpose. 4.3 CURRENT LAND USE The MLA is situated on unallocated state land. Recent land use of the Project Site includes selective logging and coal exploration. Associated infrastructure on the site includes access tracks and clearing for drill pads. Soil and Land Suitability Assessment 30 March 2010

34 4.4 PRE-MINING LAND SUITABILITY The suitability of the land to sustain beef cattle grazing, rainfed broad acre cropping and conservation is considered in relation to the Land Suitability Assessment Techniques Guideline (DME 1995) below Beef Cattle Grazing Limitations used to assess land suitability for beef cattle grazing at the Project site are as follows: Water availability; Nutrient deficiency; Soil physical factors; Salinity; Rockiness; Micro relief; ph; ESP; Wetness; Topography; Water erosion; Flooding; and Vegetation. These limitations as they relate to the suitability for beef cattle grazing are discussed individually in Tables 7-17 in terms of the soil present at the Project site, while individual limitations for the soils are presented in summarised form in Table Water Availability Plant available water capacity (PAWC) for the soil types of the Project site have been estimated by reference to Table 2.3 from the DME guidelines for Land Suitability Assessment Techniques, and is presented in Table 7. PAWC cut-off levels for each of the land suitability classes are as follows: Class 1: Class 2: >125mm mm Soil and Land Suitability Assessment 31 March 2010

35 Class 3: Class 4: Class 5: mm 50-75mm <50mm These cut-off levels are not based on a particular species of pasture, but on pasture as a general land use. Table 7: Land Suitability Classes for Beef Cattle Grazing Based on PAWC 1: Dundathu 2: Churchill Soil Type Limiting Features PAWC Rigid Soil (Sodic), ESP 6-14 within 60cm of surface, but not ESP >15 within 90cm. Rigid Soil (Sodic), ESP 6-14 within 60cm of surface, but not ESP >15 within 90cm. Land Suitability Class mm mm Nutrient Deficiency The nutrient deficiency of each soil at the Project site has been assessed against Table 2.2 of the DME guidelines for Land Suitability Assessment Techniques. The land suitability classes identified for each soil type found are presented in Table 8. Table 8: Land Suitability Classes for Beef Cattle Grazing Based on Nutrient Status 1: Dundathu 2: Churchill Soil Type Limiting Features Land Suitability Class Soil Physical Factors Sands or loams at least 75cm deep, with Phosphorus < 4ppm Sands or loams at least 75cm deep, with Phosphorus < 4ppm 4 4 The DME guidelines for Land Suitability Assessment Techniques have been used to assess the soils found at the Project site for soil physical factors, presented in Table 9. Soil and Land Suitability Assessment 32 March 2010

36 Table 9: Land Suitability Classes for Beef Cattle Grazing Based on Soil Physical Factors Soil Type Limiting Features Land Suitability Class 1: Dundathu 2: Churchill Salinity Rigid soil with a loose, soft or firm surface when dry. Rigid soil with a loose, soft or firm surface when dry. 1 1 DME guidelines have been used to determine the land suitability class against salinity parameters, with a root zone of 60cm assumed for the root zone of pasture species. This data is provided in Table 10. Table 10: Land Suitability Classes for Beef Cattle Grazing Based on Salinity Soil Type Limiting Features Land Suitability Class 1: Dundathu Rootzone EC < : Churchill Rootzone EC < Rockiness DME guidelines have been used to determine the land suitability class against rockiness issues and detailed in Table 11. Table 11: Land Suitability Classes for Beef Cattle Grazing Based on Rockiness Soil Type Limiting Features Land Suitability Class 1: Dundathu <20% course surface gravel 1 2: Churchill <20% course surface gravel Micro relief DME guidelines have been used to determine the land suitability class against Micro relief and detailed in Table 12. Table 12: Land Suitability Classes for Beef Cattle Grazing Based on Micro relief Soil Type Limiting Features Land Suitability Class 1: Dundathu Melonholes cover <20% surface area 1 2: Churchill Melonholes cover <20% surface area 1 Soil and Land Suitability Assessment 33 March 2010

37 ph DME guidelines have been used to determine the land suitability class against the parameter of ph. The data is provided in Table 13. Table 13: Land Suitability Classes for Beef Cattle Grazing Based on ph Soil Type Limiting Features Land Suitability Class 1: Dundathu ph : Churchill ph Exchangeable Sodium Percent (10cm) Land suitability classes based on Exchangeable Sodium Percent (ESP) in the top 10cm of soil have been determined as per the DME guidelines. The results are illustrated in Table 14. Table 14: Land Suitability Classes for Beef Cattle Grazing Based on ESP excl. Al. Soil Type Limiting Features Land Suitability Class 1: Dundathu ESP : Churchill ESP Wetness The DME guidelines have been used to determine the land suitability class, in respect to Wetness parameters, and these are detailed in Table 15. Table 15: Land Suitability Classes for Beef Cattle Grazing Based on Wetness Soil Type Limiting Features Land Suitability Class 1: Dundathu Shallow seasonal and permanent swamps 3 2: Churchill Low Lying level plains Water Erosion DME guidelines have been used to determine the land suitability class against the parameter of water erosion. The data is provided in Table 16. Table 16: Land Suitability Classes for Beef Cattle Grazing Based on Water Erosion Soil Type Limiting Features Land Suitability Class 1: Dundathu Slopes 1-3% on sodic rigid soils 2 Soil and Land Suitability Assessment 34 March 2010

38 2: Churchill Slopes 1-3% on sodic rigid soils Flooding The capacity of each soil type to flooding has been assessed by the DME guidelines and details below in Table 17. Table 17: Land Suitability Classes for Beef Cattle Grazing Based on Flooding Soil Type Limiting Features Land Suitability Class 1: Dundathu Periodic flooding 2 2: Churchill Periodic flooding 2 Soil and Land Suitability Assessment 35 March 2010

39 Summary of Land Suitability Classes for Beef Cattle Grazing The land use suitability limitations for Beef Cattle Grazing are summarised below in Table 18. Soil Type PAWC Nutrients Physical Salinity Rockiness Table 18: Land Suitability Limitations for Beef Cattle Grazing Micro relief ph ESP (10cm) Wetness Erosion Flooding 1: Dundathu : Churchill Overall Suitability Rating Soil and Land Suitability Assessment 36 March 2010

40 Summary Suitability for Beef Cattle Grazing The two soil management units discussed in this report would be marginally suitable for beef cattle grazing and have each been assigned a Land Suitability Class of 4. The land suitability classes for beef cattle grazing at the Maryborough site are summarised in Table 19, and their distribution outlined in Figure 9. Native pastures are expected to have a low to moderate productivity in their virgin state with potential for pasture improvement requiring major inputs to ensure sustainability. These inputs may not be justified by the benefits to be obtained in using the land for the particular purpose and is hence considered presently unsuited. Table 19: Pre-mining Suitability for Beef Cattle Grazing Soil Type Class Limitations Area 1: Dundathu 4 2: Churchill 4 Land which is marginally suited for a proposed use and would require major inputs to ensure sustainability. Limitations exist largely in respect to the soils nutrient deficiency and high levels of exchangeable sodium. Land which is marginally suited for a proposed use and would require major inputs to ensure sustainability. Limitations exist largely in respect to the soils nutrient deficiency and high levels of exchangeable sodium ha ha Soil and Land Suitability Assessment 37 March 2010

41 Figure 9: Pre-Mining Land Suitability Beef Cattle Grazing Soil and Land Suitability Assessment 38 March 2010

42 4.4.2 Rainfed Broadacre Cropping Limitations used to assess land suitability for rainfed cropping at the Project site are as follows; Water availability; Nutrient deficiency; Soil physical factors; Soil workability; Salinity; Rockiness; Micro relief; Wetness; and Flooding. These limitations are discussed in Tables for each soil type present on the Project site and are summarised in Table Water Availability PAWC for the soil types of the Project site have been estimated by reference to Table 2.3 from the DME guidelines for Land Suitability Assessment Techniques. PAWC cut-off levels for each of the land suitability classes are as follows: Class 1: Class 2: Class 3: Class 4: Class 5: >150mm mm mm mm <75mm The land suitability classes identified for each soil type found are presented in Table 20. Soil and Land Suitability Assessment 39 March 2010

43 Table 20: Land Suitability Classes for Rainfed Broadacre Cropping Based on PAWC 1: Dundathu 2: Churchill Soil Type Limiting Features PAWC Nutrient Deficiency Rigid Soil (Sodic), ESP 6-14 within 60cm of surface, but not ESP >15 within 90cm. Rigid Soil (Sodic), ESP 6-14 within 60cm of surface, but not ESP >15 within 90cm. Land Suitability Class mm mm 4 Nutrient deficiency for the soil management units at the Project site have been assessed against Table 2.1 of the DME guidelines for Land Suitability Assessment Techniques. The land suitability classes identified for each soil management unit observed are presented in Table 21. Table 21: Land Suitability Classes for Rainfed Broadacre Cropping Based on Nutrient Status Soil Type Limiting Features Land Suitability Class 1: Dundathu P < 10ppm and Exchange K < 0.3 meq. %. 4 2: Churchill P < 10ppm and Exchange K < 0.3 meq. % Soil Physical Factors The DME guidelines for Land Suitability Assessment Techniques have been used to assess the soils found at the Project site for soil physical factors. The land suitability classes identified for each soil type found are presented in Table 22. Table 22: Land Suitability Classes for Rainfed Broadacre Cropping Based on Physical Factors 1: Dundathu 2: Churchill Soil Type Limiting Features Land Suitability Class Soil Workability Rigid soil with a loose, soft, or firm surface when dry. Rigid soil with a loose, soft, or firm surface when dry. 1 1 The land suitability classes determined for soil workability for the soil management units identified within the Project site are presented in Table 23. Table 23: Land Suitability Classes for Rainfed Broadacre Cropping Based on Soil Workability 1: Dundathu 2: Churchill Soil Type Limiting Features Land Suitability Class Rigid soil with a loose, soft, or firm surface when dry. Rigid soil with a loose, soft, or firm surface when dry. 1 1 Soil and Land Suitability Assessment 40 March 2010

44 Salinity DME guidelines have been used to determine the land suitability class against salinity issues, with a root zone of 100cm assumed for the root zone of rainfed cropping species. The land suitability classes identified for each soil type are presented in Table 24. Table 24: Land Suitability Classes for Rainfed Broadacre Cropping Based on Salinity Soil Type Limiting Features Land Suitability Class 1: Dundathu Rootzone EC < : Churchill Rootzone EC < Rockiness DME guidelines have been used to determine the land suitability class against rockiness parameters and detailed in Table 25. Table 25: Land Suitability Classes for Rainfed Broadacre Cropping Based on Rockiness Soil Type Limiting Features Land Suitability Class 1: Dundathu < 10% course surface gravel 1 2: Churchill < 10% coarse surface gravel Micro relief DME guidelines have been used to determine the land suitability class against Micro relief. This is detailed in Table 26. Table 26: Land Suitability Classes for Rainfed Broadacre Cropping Based on Micro relief Soil Type Limiting Features Land Suitability Class 1: Dundathu No melonholes 1 2: Churchill No melonholes Wetness DME guidelines have been used to determine the land suitability class against wetness parameters. The results have been illustrated in Table 27. Table 27: Land Suitability Classes for Rainfed Broadacre Cropping Based on Wetness Soil Type Limiting Features Land Suitability Class 1: Dundathu Seasonal swamps and low-lying run-on areas 4 2: Churchill Seasonal swamps and low-lying run-on areas 4 Soil and Land Suitability Assessment 41 March 2010

45 Topography DME guidelines have been used to determine the land suitability class against topography measures and are detailed in Table 28. Table 28: Land Suitability Classes for Rainfed Broadacre Cropping Based on Topography 1: Dundathu Soil Type Limiting Features Land Suitability Class Occasional deep gullies impede cultivation slightly 2: Churchill No gully dissection Water Erosion This limitation covers accelerated soil loss, which results in declining productivity, increasing difficulty to cultivate and eventually the inability to produce a crop in most years. The land suitability classes identified for each soil type observed are presented in Table 29. Table 29: Land Suitability Classes for Rainfed Broadacre Cropping Based on Water Erosion Soil Type Limiting Features Land Suitability Class 1: Dundathu Slopes 1-2% on sodic rigid soils 3 2: Churchill Slopes 1-2% on sodic rigid soils Flooding The susceptibility capacity of each soil type to flooding has been assessed against the DME guidelines. Details are given below in Table 30. Table 30: Land Suitability Classes for Rainfed Broadacre Cropping Based on Flooding Soil Type Limiting Features Land Suitability Class 1: Dundathu Regular flooding 5 2: Churchill Occasional flooding 4 Soil and Land Suitability Assessment 42 March 2010

46 Summary of Land Suitability Classes for Rainfed Broadacre Cropping The land use suitability limitations for Rainfed Broadacre Cropping are summarised below in Table 31. Table 31: Land Suitability Limitations for Rainfed Broadacre Cropping Soil Type PAWC Nutrients Physical Workability Salinity Rockiness Micro relief Wetness Topography Erosion Flooding 1: Dundathu : Churchill Overall Suitability Rating Soil and Land Suitability Assessment 43 March 2010

47 Summary Suitability of Land for Rainfed Broadacre Cropping The land suitability classes for rainfed broadacre cropping at the Colton Coal Project site are summarised in Table 32 and their distribution outlined in Figure 10. Table 32: Pre-mining Suitability for Rainfed Broadacre Cropping Soil Type Class Limitations Area 1: Dundathu 5 2: Churchill 4 Unsuitable land with extreme limitations, land which is unsuitable and cannot be sustainably used for a proposed use. Limitations exist primarily in regards to flooding, followed by several other parameters. Land which is marginally suited for a proposed use and would require major inputs to ensure sustainability. Limitations exist largely in respect to soil and surface hydrology and nutrient deficiency ha ha Soil and Land Suitability Assessment 44 March 2010

48 Figure 10: Pre-Mining Land Suitability Rainfed Broadacre Cropping Soil and Land Suitability Assessment 45 March 2010