NAC Rehabilitation Monitoring 2024 Final

P RE P ARE D B Y

ABN 84 627 497 509

0408 474 248

clayton@minesoils.com.au https://www.minesoils.com.au Tamworth NSW 2340

D I SC L A I ME R

This report has been prepared by Minesoils Pty Ltd with all reasonable skill, care and diligence, and taking account of the timescale and resources allocated to it by agreement with the Client. Information reported herein is based on the interpretation of data collected, which has been accepted in good faith as being accurate and valid.

This report is for the exclusive use of New Acland Coal Pty Ltd. No warranties or guarantees are expressed or should be inferred by any third parties. This report may not be relied upon by other parties without written consent from Minesoils. Minesoils disclaims any responsibility to the Client and others in respect of any matters outside the agreed scope of the work.

D O C U ME N T C ON T RO L

T AB L E O F CO NT E NT S

List of Figures

Figure 1. Rehabilitation Areas and Monitoring Locations

List of Appendices

Appendix 1. Soil Results - NAC Rehabilitation Monitoring Appendix 2. Vegetation Results - NAC Rehabilitation Monitoring Appendix 3. Long Term Comparative Monitoring

Appendix 4. Geotechnical Stability Results

Appendix 5. Rehabilitation Site and Profile Descriptions Appendix 6. Soil Laboratory Results

1. ‌O VE RVI E W

   1. ‌INTRODUCTION

      Minesoils Pty Ltd (Minesoils) was engaged by New Acland Coal Pty Ltd (NAC) to conduct the 2024 rehabilitation monitoring and reporting for the New Acland Coal Mine (New Acland). This rehabilitation monitoring and reporting addresses conditions imposed on mine operations under the Environmental Authority (EA) (EPML00335713) specifying the requirement to rehabilitate disturbed land to levels defined previously in the NAC Final Land Use and Rehabilitation Plan (FLURP), and now in the Progressive Rehabilitation and Closure Plan (PRCP) for New Acland, which is currently awaiting approval.

   2. ‌BACKGROUND

      NAC, part of the New Hope Group, has operated New Acland since 2002. The Mine's operations are currently authorised under Mining Leases (ML)50170, ML50216, ML50232 and ML700002, and in May 2023 recommenced mining operations in ML50232 following a period under care and maintenance. New Acland is located approximately 15 km north of Oakey in the Darling Downs region of Queensland.

      Rehabilitated land is defined by NAC as disturbed land that has been re-profiled, topsoiled, and seeded with improved pasture species and left to naturally develop for more than 12 months, with a view to ultimately sustain a grazing land use. Progressive rehabilitation of disturbed land, including recontoured spoil/waste rock dump areas, has been undertaken at NAC since 2005. An annual rehabilitation monitoring program has been in place at NAC since 2013. The monitoring program is based on defined soil and ecological rehabilitation targets derived using the FLURP, industry publications, grazing land suitability criteria and data derived from nearby reference (analogue) sites targeting a range of grazing suitability classes.

      Several of the FLURP rehabilitation targets have been modified since the inception of this Project, however the general approach to rehabilitation remains the same, and is now reflected in the PRCP. Consistency with the original FLURP rehabilitation criteria has been maintained where relevant. This approach will continue to build on the existing knowledge base which is able to be carried forward into the certification process.

   3. ‌REHABILITATION APPROACH

      The objective of rehabilitation at New Acland is to return the land to the agreed post-mining land use of grazing, including naturally shaped landforms, contoured embankments and depressed areas corresponding to former pit locations. The rehabilitation treatments which have been used as part of the program to date have comprised:

      • Grading overburden to a maximum slope gradient of 20%;

      • Spread a minimum of 250 millimetres depth of topsoil over re-contoured land;

      • Application of appropriate ameliorants to enhance the quality of soil and therefore improve plant health, growth and revegetation;

      • Seeding with an approximate seed mix or suitable equivalent; and

      • Application of appropriate fertiliser(s) for vegetation establishment as required.

        NAC employ a process of reinstating both constructed 'lower soil' and 'upper soil' horizontal profiles (where materials management and volumes of stored material permit). This process involves sequential stripping of in situ soils, followed by separate stockpiling of topsoil and subsoil material for storage. At the time of rehabilitation, the reinstatement of soils seeks to establish an upper and lower horizon.

        The aim of this approach is to capitalise on the inherent features of topsoils which may promote growth and biodiversity (such as the existing seed bank and increased organic fractions providing nutrients and structural improvements), whilst providing a lower soil profile for water holding capacity and suitable rooting depths, which are more consistent with the natural soils in the region.

        pg. 4

   4. ‌REHABILITATION STATUS

      As of the rehabilitation monitoring period of 2024 (November 2024), a total of 698 ha of land had been rehabilitated within the Mining Lease areas, as presented in Table 1.

      Table 1: Rehabilitated Land Areas

      Pit Area of Rehabilitated Land (ha)

      North 307

      South 190

      Centre 67

      West 70

      TSF 30

      IPT1 34

      Total 698

   5. ‌ASSESSMENT OBJECTIVES

      NAC has engaged Minesoils to assess the progress of existing rehabilitated areas which cover approximately 354 hectares (ha), against rehabilitation targets (refer Figure 1) for the 2024 period. The rehabilitation monitoring program was completed in November 2024.

      The objectives of the New Acland rehabilitation monitoring program are as follows:

      • Undertake consistent and standardised monitoring, with a view to obtain a dataset to monitor progress

        against benchmarks whilst also fulfilling the company's EA requirements.

      • Assess when rehabilitation targets have been reached.

      • Identify corrective actions/recommendations (i.e. maintenance and remedial works).

      • Provide feedback for continuous improvement of the rehabilitation process at New Acland.

      • Identify any specific issues, which may require further consideration.

      • Provide information for stakeholders.

      • Provide rehabilitation data suitable for inclusion in forming agreed rehabilitation targets for progressive rehabilitation certification to progress towards ML surrender.

   6. ‌REPORT STRUCTURE

This report is structured as follows:

Section 1 Overview - presents the background to rehabilitation at New Acland and presents the purpose and objectives of this report.

Section 2 Regulatory Context - outlines current regulatory status and requirements of rehabilitation monitoring.

Section 3 Rehabilitation Monitoring Methodology - outlines approach and design of monitoring program.

Section 4 Results - provides a summary of key findings of the monitoring program.

Section 5 Recommendations - discusses status of rehabilitation against targets and makes recommendations for further progress.

Figure 1. Rehabilitation Areas and Monitoring Locations

1. ‌RE G U L ATO RY C O N TE XT

   Conditions imposed under the Environmental Authority (EA) (EPML00335713) specify the requirement to rehabilitate disturbed land to levels as defined within the initial Final Land Use and Rehabilitation Plan (FLURP) and the currently submitted, not-yet-approved PRCP. The overarching goal of the rehabilitation is to receive certification of progressive rehabilitation, which will allow the eventual surrender of the EA associated with the mining leases. To support this goal, the rehabilitation monitoring program was set up to provide a consistent framework for the monitoring and reporting of rehabilitation as stipulated within the PRCP. Monitoring of the progressive rehabilitation provides evidence that acceptance criteria have been achieved and sustained.

   Based on the Rehabilitation program results, NAC will continue to explore opportunities for progressive rehabilitation certification for compliant areas. The EA holder can apply to request certification of their progressive rehabilitation during the life of the project. Once certified, additional changes to rehabilitation conditions within the EA will not impact on the certified areas.

   NAC was granted "progressive certification for a resource project" on 1st of November 2018. Mining activities in North Pit commenced during late 2002 and ceased in 2008 and is now fully rehabilitated, with 344 hectares of this land parcel 'certified' as progressive rehabilitation by the Department of Environment, Tourism, Science and Innovation, as at 31st July 2023. Assuming that NAC continues to receive certification on the progressively rehabilitated areas, there are several potential considerations moving forward:

   • The certified area will require on-going maintenance (e.g. weeds and pests) to protect against deterioration while still within the lease responsibility. This includes prevention of re-disturbance.

   • There may be value in continuing monitoring outside of any EA conditions, including:

     • Providing key baseline data for closure (i.e. measurements against future rehabilitation).

     • Validate the success trajectory.

     • The option to adjust or reduce current monitoring to better suit internal requirements.

     • Check for longer term issues, as some vegetative communities (particularly under environmental stress) may change over time.

     • Provide research opportunities for rehabilitation monitoring.

   • Certification to support a partial surrender application to DETSI.

   To undertake partial surrender, applications must include a compliance statement that outlines the extent to which activities have complied with the conditions of the EA. The application must also include a final rehabilitation report. If the DETSI refuses the surrender application, they may direct the company to carry out further rehabilitation through "rehabilitation direction".

2. ‌RE H AB I L I T AT IO N MO N I T O RIN G M ET HO D OLO G Y

   1. ‌MONITORING PROGRAM DESIGN

      The methodology for the monitoring program was developed using reference site data and rehabilitation targets (as no pre-disturbance baseline data was available). Ongoing monitoring of reference sites serves as a control for environmental variability in the assessment, with reference sites reflecting current seasonal conditions.

      The following provides further discussion of reference/monitoring site selection, evolution of the program, and the assessment methodology employed.

      Further soil studies have been undertaken in 2015 and 2017 which have provided additional reference materials that are able to be matched with the characteristics of the soils currently stockpiled as well as soils proposed to be stripped. These additional references will also be available to ensure 'back up' data is available for comparison against soil characteristics within the rehabilitated profiles.

      Analogue Sites

      Four permanent analogue sites (R01, R02, R03 and R04) were originally established for the FLURP to represent grazing land suitability classes 2, 3, 4 and 5 (refer to Section 3 of the initial FLURP). The analogue sites were selected to provide benchmark data for the vegetation and soil indicators in the development of rehabilitation targets.

      An additional analogue site (R05) was added in 2014 with the intention of eventually replacing R03, however the advance of the West Pit resulted in R05 being mined out in 2016. A second analogue site (R06) for the grazing class 2 land was established in 2016 to replace R03. As such, the following four analogue sites are active as of the 2024 monitoring period:

      • R01 (2013)

      • R02 (2013)

      • R04 (2013)

      • R06 (2016)

      It is Minesoils' recommendation that sites R01, R02, and R04 are removed as analogue sites. The location of analogue sites are shown in Figure 1 and described in Table 2.

      Table 2: Rehabilitation Monitoring Analogue Sites

      Site	Easting	Northing	Grazing Land Suitability Class	Status
      R01	375142	6980991	Class 4	Active
      R02	375271	6980962	Class 3	Active
      R03	371717	6979167	Class 2	Not active - mined in 2016
      R04	372231	6979083	Class 5	Active
      R05	370895	6979913	Class 2	Not active - mined in 2015
      R06	374121	6978662	Class 2	Active

      Monitoring Sites

      Permanent rehabilitation monitoring sites have been located across two different rehabilitated pit areas at a density of one site per 20 hectares and at least one site per year of rehabilitation. A total of 41 existing monitoring sites have been established prior to the 2024 monitoring round with one additional location (M42) targeting newly rehabilitated land. Sites M1 - M23 were relinquished in 2018 as part of the progressive certification.

      pg. 8

      The vegetation-pasture assessment was expanded to cover other areas including rehabilitation area walk throughs to provide a high level assessment of the entire rehabilitation area. Whilst these walkthroughs are not suited to scientific analysis, they do provide a valuable opportunity to identify areas which may not be represented by the permanent monitoring points, as well as trigger management opportunities.

      The locations of the 2024 active monitoring sites are shown in Figure 1 and described in Table 3.

      Table 3: Rehabilitation Monitoring Sites

      Monitoring Site	Coordinates		Year of Rehabilitation	Location	Rehabilitation Status
      	Easting	Northing
      M24	372962	6980629	2016	North Pit	Active
      M25	373358	6980208	2016	South Pit	Active
      M26	373964	6979446	2016	South Pit	Active
      M27	373583	6979832	2017	South Pit	Active
      M28	371509	6981433	2017	TSF	Active
      M29	372457	6982137	2019	IPT1	Active
      M30	372343	6982284	2019	IPT1	Active
      M31	372246	6979776	2019	Centre Pit	Active
      M32	372671	6979793	2019	Centre Pit	Active
      M33	372531	6981840	2020	North Pit	Active
      M34	371911	6980330	2020	Centre Pit	Active
      M35	370542	6979761	2020	West Pit	Active
      M36	370307	6979860	2020	West Pit	Active
      M37	372426	6981842	2021	North Pit	Active
      M38	371896	6980599	2021	Centre Pit	Active
      M39	370589	6980455	2021	West Pit	Active
      M40	371238	6979722	2021	West Pit	Active
      M41	371924	6982115	2021	North Pit	Active
      M42	370796	6980700	2021	West Pit	Active

   2. ‌ASSESSMENT TECHNIQUES

      This section outlines the assessment techniques used to measure vegetation, soils and geotechnical performance.

      Vegetation Assessment

      Permanent monitoring plots were used for the assessment of vegetation indicators at both reference and monitoring sites. Existing plots were resurveyed at relevant sites, and new plots established where required. Relevant components of the BioCondition method (Eyre et al., 2011) were utilised, comprising:

      • one 50 x 10 metre plot: assessed for plant species richness, declared weeds and erosion.

      • five 1 x 1 metre quadrats: assessed for ground cover.

        Sites were marked out by laying out a 50 metre centre-line transect that follows the contour, i.e. along a slope as opposed to up or down a slope, and encompassing 5 metres either side of the transect. The centre of the site (25 metre point on the transect) intersected the demarcated monitoring position. This equates to the CORVEG standard

        plot area used by the Queensland Herbarium (see Neldner et al., 2012). Five 1 x 1 metre quadrats were located on alternate sides of the 50 metre centre-line, 10 metres apart, example shown below (not to scale).

        
        
        

        All native and exotic plants (trees, shrubs, grasses and forbs/herbs) including weeds of national significance (declared weeds) were identified within the 50 x 10 metre plot. The location, number and dimensions of all active erosion (rill/gully/sheet) areas were also recorded. The percentage cover of grass, shrub, herb/forb, organic litter, rock and bare earth within five 1 x 1 metre quadrats was assessed. The mean vegetation cover across all five quadrats was calculated.

        Photographs were collected to document change over time, including landscape photos to record groundcover, and four photos: north, south, east and west of the plot centre to record general conditions and landscape of the site.

        Soils Assessment

        Each soil-profile exposure was excavated by a backhoe/excavator to either a depth of 1.2 metres, to equipment refusal, or to bedrock/overburden, in line with the Australian Soil and Land Survey Field Handbook (NCST, 2009). For sites assessed in previous years, excavation occurred within 5 metres (approximately) of the previous sampling location (where previous locations were able to be identified).

        Prior to the 2018 monitoring program, a hand auger or shovel was used to expose a soil profile at each of the reference and monitoring sites. The pit excavated by a backhoe provides more valuable insight into soil layer depths, boundary shapes, soil structure development, bioturbation, root development and general soil profile consistency.

        Information at each site was recorded, and photographs of the surrounding landscapes and of the soil surface condition were taken. The soil profile was described following the methods of the Australian Soil and Land Survey Field Handbook (NCST, 2009).

        In previous years, both a topsoil (A horizon) and subsoil (B horizon) sample was collected for laboratory analysis. However, in 2023 it was proposed only a topsoil sample be collected annually with subsoil samples collected every second or third year. The applicable tests for soil properties are detailed in Table 4. Full laboratory results are presented in Appendix 6.

        Table 4: Laboratory Analysis

        Soil Property	Assessment Testing Method	Method Code/ Reference
        pH	1:5Ca (0.01M CaCl2 extract)	4B1A
        EC	1:5/se	14B1A
        Exchangeable cations and Cation Exchange Capacity (CEC)	1M ammonium chloride at pH 7.0 (pretreatment for soluble salts)	15A2A
        Exchangeable Sodium Percentage (ESP)	Calculated (100 x (Exch. Na/ CEC))	15A2A
        Organic Matter and Total Organic Carbon (TOC)	AS 1289.4.1.1-1997	NEPM (2013)
        Aggregate stability	Emerson Dispersion Test	AS 1289.3.8.1.2006
        Total metals	Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP/AES)	USEPA 200.2/ ICP/AES, CV/ FIMS/ ICPMSC
        Field texture	Ribbon test of the fine earth fraction	ASLS Field Handbook (NCST 2009)
        Depth of Effective Root Zone (ERZ)	Calculated in accordance with a soil texture look-up table using the soil texture classes, an acceptable procedure for estimating depth of ERZ	LRB (1990) RPI Regulations (2014) ASLS Field Handbook (NCST 2009)
        Soluble Chloride	1:5 Soil/Water Leach, APHA 4500 Cl--G	ED045C

        Geotechnical Assessment

        Assessments of slope and geotechnical stability were undertaken by NAC surveyors at all existing and new analogue and monitoring sites. Assessment techniques included:

      • Slope percentage was measured in line with the former Queensland strategic cropping land guidelines (DERM, 2011) over a distance of 50 metres straddling the centre point of each transect directly up-down the slope (perpendicular to the contour line) at each site using GPS Survey Equipment. At some sites, this was limited to 20 metres due to the boundary of the rehabilitation.

      • Reduced Level (RL) from the Australian Height Datum (AHD) was measured, using GPS Survey equipment, from three (3) point readings at each site from the start, middle and end of each transect. The RL readings taken will form the baseline to detect whether subsidence is occurring at any of the monitoring sites, as an indicator of geotechnical stability.

        The change in RL was calculated for those sites where baseline data exists (i.e. monitoring and analogue sites from previous monitoring events). The geotechnical stability data is provided in Appendix 4.

   3. ‌REHABILITATION TARGETS

      Site-specific rehabilitation targets have been established at New Acland to assess the success of rehabilitation. The

      rehabilitation indicators, criteria targets or 'trigger levels' for corrective action are listed in Table 5.

      ‌Table 5: Rehabilitation Target Criteria

      Indicator	Target Criteria
      Ecological
      Vegetation cover	≥70%
      Grass species diversity	≥3 pasture species
      Declared weeds (National Significance)	<5% of total pasture density
      Geomorphological
      Slope	<20%
      Active rill/gully erosion	Rill/gully erosion has been managed to be consistent with surrounding in-situ landforms. Identification of areas of concern (e.g. large scale rill/gully)
      Geotechnical stability	Stable surface, no subsidence
      Soil Physical
      Field texture	Sandy loam to light clay (rigid soils i.e. duplex soils) Clay loam to heavy clay (non-rigid soils i.e. Vertosols)
      Emerson Aggregate Test (EAT)	Class 2, 3, 4, 5 or 6
      Depth of effective root zone (ERZ)	250 - 1000 millimetres
      Soil Chemical
      pH	pHw 6.5 - 9.5, pHCa 6.0 - 8.0
      Electrical Conductivity (EC/se)	EC1:5w 120 - 240 µS/cm for low salinity in sandy soils 90 - 300 µS /cm for low salinity in clay soils ECse <1,900 µS/cm for low salinity in all soils
      Cation Exchange Capacity (CEC)	9 - 45 meq/100 gm
      Exchangeable Sodium Percentage (ESP)	<10%
      Total metals - B, Co, Cu, Mn, Mo, Zn	Risk Based Ecological Levels Zn - 190 mg/kg, Cu - 90 mg/kg Typical Background Levels Cu - 3-412 mg/kg, Mn - 4-7,357mg/kg, Mo - 0.2-5.2 mg/kg, Zn - 5-92mg/kg, B - 0.09-8 mg/kg, Co - <6-165 mg/kg
      Total Organic Carbon (TOC)	>1% for total organic carbon

   4. ‌FINAL LAND USE AND REHABILITATION PLAN (FLURP)

      Rehabilitation targets were developed with consideration of the FLURP and previous rehabilitation criteria. Preliminary site-specific rehabilitation targets were previously developed for NAC by SKM in 2008. Targets were developed with consideration of the FLURP proposed rehabilitation criteria, closure literature and benchmark data derived from reference sites for grazing Land Suitability Classes 2 to 5. Rehabilitation targets have been reviewed and refined as necessary following monitoring as part of the continual improvement process.

      As part of the Supplementary Environmental Impact Statement for the Stage 3 Expansion, a revised FLURP was prepared to articulate the rehabilitation process going forward. The current FLURP refines the rehabilitation targets across NAC and supersedes those in previous versions.

      It is noted that the FLURP provides a more pragmatic approach to rehabilitation targets and, for example, discusses elevated out-of-pit dump final landforms as requiring slopes within a range of 15% to 30%. Other soil chemical factors including ESP, root zone salinity and cation exchange capacity are to be monitored at select sites.

      The FLURP was further revised in 2022 as part of the Stage 3 approval process, which included commitments to stripping and stockpiling of individual soil units, the recreation of land suitable for use as Strategic Cropping Land (SCL) and the establishment of a much greater number of reference/analogue sites for comparison with rehabilitation success.

      Under the EA it is required that a Progressive Rehabilitation and Closure Plan (PRCP) be developed and implemented and that it is to be updated as operations evolve. The Department of Environment, Tourism, Science and Innovation (DETSI) calls mines into the PRCP program. NAC has not been transitioned into the PRCP program to date. The PRCP will replace the previously named FLURP for NAC.

      Rehabilitation targets have been continually reviewed and refined as necessary following monitoring as part of

      NAC's continual improvement process. Refer to Table 10 for proposed changes to these targets for 2025.

   5. PROGRESSIVE REHABILITATION AND CLOSURE PLAN (PRCP)

      In accordance with the transition notice issued under section 754 of the EP Act on 31 May 2022 to New Acland Coal Pty Ltd (NAC), a PRCP that meets the legislative requirements in section 126C and 126D of the EP Act and the statutory guideline: Progressive Rehabilitation and Closure Plans (ESR/2019/4964 Version 3) has been developed by NAC and submitted to DETSI for approval on 27 June 2024. Once approved, NAC's PRCP will supersede the final version of the FLURP accordingly.

3. ‌RE SU L T S

   1. ‌CLIMATE CONDITIONS

      Weather at the time of field work was dry with average daily temperatures reaching a maximum of 29.9 °C. While the minimum and maximum temperatures were variable, they are generally in line with previous years' monitoring events. The annual rainfall totals for the previous 9 years are shown in Table 6. Following a period of drought which ended in 2020 there were several years of above average rainfall. The annual totals for 2023 and 2024 have returned closer to average levels, with conditions conducive to pasture growth prior to sampling.

      Table 6: Monthly Rainfall at Oakey Airport (Station 41359)

      Year	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Annual
      2016	78.2	59.8	14.8	14.8	12.6	64.8	30.0	9.2	94.4	19.8	84.6	50.8	563.8
      2017	48.6	31.6	160.4	12.4	8.4	17.6	34.2	1.8	0.2	100.4	14.0	94.2	523.8
      2018	47.0	79.2	85.6	3.8	6.8	13.8	7.8	4.8	9.2	93.4	32.6	55.6	439.6
      2019	1.4	5.4	70.0	1.2	4.2	11.6	0.0	7.2	1.6	31.8	1.8	33.4	169.6
      2020	160.8	229.6	25.8	0.8	23.6	29.8	17.0	35.0	1.2	96.2	3.0	75.8	698.6
      2021	80.0	9.4	146.6	22.8	44.2	47.2	47.4	9.6	13.8	102.0	165.6	116.8	805.4
      2022	43.8	226.4	154.6	28.4	98.4	21.0	39.0	37.4	52.6	47.8	39.4	64.8	853.6
      2023	76.0	16.8	81.2	61.0	57.0	2.6	21.6	2.0	5.6	4.2	97.0	74.0	499.0
      2024	75.0	27.4	38.6	79.6	25.4	10.2	31.8	16.0	28.0	21.8	109.6	107.8	571.2
      LTA*	78.3	80.4	55.0	30.1	39.8	28.9	28.5	24.9	29.0	57.1	74.5	90.4	618.0

      *Long Term Average (1970-2024)

   2. ‌ANALOGUE SITES

      Site Descriptions

      Analogue Sites represent grazing Land Suitability Classes 2 to 5. A full description of each analogue site is provided in Appendix 5. The analogue sites were classed under the Australia Soil Classification (ASC) as follows: R01 - Grey Vertosol; R02 - Red Chromosol; R04 - Shallow Brown Dermosol; and R06 - Black Vertosol. Note that previous reports had these profiles listed as all Vertosols. Refer to Appendix 5 for soil profile information to confirm revised classification.

      Analogue sites R01, R02, and R06 are situated on alluvial plains and broad drainage lines. Site R01 is located on a constructed levee bank between a drainage line and Lagoon Creek. Site R02 is located on the floodplain of Lagoon Creek. Site R06 is located in disturbed pastures in a floodplain to the south of the NAC mining operations. Site R04 is located on the crest of Bottle Tree Hill.

      None of these sites were assessed in 2024 monitoring based on the recommendation from 2023 to exclude R01, R02, and R04 sites due to lack of representation of required soil profiles. 2023 data is provided in Appendix 1 and 2 with full comparative results from all monitoring years shown in Appendix 3.

      Vegetation Results (2023 for Reference)

      Analogue site data for vegetation indicators (vegetation cover, grass species diversity and declared weeds) are provided in Table 7.

      Vegetation cover in these areas is generally consistent with previous monitoring years with excellent coverage and 100% groundcover. Pasture species in R01 and R02 consisted of QLD Bluegrass, Rhodes Grass, Aristida and minor areas of Couch. R04 had more diversity and was dominated by Panic and Aristada. R06 was more aligned with a pasture improved paddock and was dominated by QLD Bluegrass, Bisset Creeping Bluegrass, Rhodes Grass, Plantain, and Vetch.

      Good seasonal conditions have led to excellent pasture growth and species diversity. Previously rehabilitation monitoring has been undertaken in spring and summer, however 2022 and 2023 field assessment was undertaken in August and July respectively.

      Vegetation present at Sites R01, R02 and R04 also consists of a 10 - 20% tree and shrub layer comprising of Acacia species, Poplar Box (Eucalyptus populnea) and Belah (Casuarina cristata) with Narrow-Leaved Bottle Tree (Brachychiton rupestris) also present at site R04.

      No declared weed species were observed at the analogue sites. It was noted that recent management of Velvety Tree Pear (Opuntia tomentosa) and Common Prickly Pear (Opuntia stricta) at sites R02 and R04 has been effective this monitoring round. Although some weed species are present at the analogue sites, density is considered to be less than 5% total vegetation coverage.

      Table 7: Summary of Analogue Site Vegetation Criteria

      Site	Vegetation Cover	Grass Species Diversity	Declared Weed Species
      R01	100	3	0
      R02	100	3	0
      R04	100	3	0
      R06	100	3	0

      Legend for all tables

      Meets or exceeds criteria

Soil chemical conditions noted in this round of rehabilitation monitoring are generally consistent with previous results at analogue sites. Each Analogue site had favourable soil chemical conditions, with no limitations for plant growth. A summary of soil results for analogue sites compared to rehabilitation completion criteria is shown in Table . Note the results for ECw and EAT are outside the target range however these values are not prohibitive to plant growth (Refer to Table 10 for explanation and justification for modifying the criteria levels).

Table 8: Summary Analogue Site Soil Indicators

No obvious instances of soil erosion were noted at any of the analogue sites. There was a high vegetation cover across the majority of NAC, which appeared to stabilise most surface soils. Given this ground cover, it is considered that there is limited potential for erosion to occur. Full monitoring data for slope measurements is provided in Appendix 4.

1. 1. ‌REHABILITATION SITES

      Site Descriptions

      A description of all rehabilitation sites is provided in Appendix 5. A review of the location of each of the monitoring sites relative to planned New Acland activities has confirmed that they remain suitable for future monitoring programs. All rehabilitation sites are classified as Anthroposols using ASC soil nomenclature.

      Rehabilitation criteria indicators are only described by exception in the following sections, i.e. only those sites and criteria which were below or above the assigned threshold levels are described.

      Vegetation Results

      Rehabilitation site data for vegetation indicators (vegetation cover, grass species diversity, declared weeds) are provided in Appendix 2. There were 14 rehabilitated sites that currently meet the three target vegetation outcomes of vegetation cover, grass species diversity and declared weed species. Sites 24, 29, 30, and 42 showed less than the target number of grass species. Vegetation groundcover is greater than 70% at all rehabilitation sites except for M24, which shows 50% groundcover.

      The most common declared weed species, African Boxthorn (Lycium ferocissimum), has been well controlled since the 2018 monitoring, however scattered areas still exist at sites 24, 25, 26, 33, and 36. Continued management of African Boxthorn over affected sites is recommended to treat existing infestations and prevent further invasion. The current control program is doing an excellent job of reducing the African Boxthorn populations at impacted sites.

      Turnip weed (Sisymbrium thellungii) and Cotton Bush (Gomphocarpus fruticosus) are not identified as declared weeds but are invasive and could impact the successful establishment and growth of pasture within rehabilitation sites. These weeds are present at several rehabilitation sites (refer to profile sheets). Minesoils recommends these invasive species are treated during the African Boxthorn control program to prevent further infestation and allow excellent continued pasture establishment.

      Table 7: Summary of Analogue Site Vegetation Criteria

      Site	Vegetation Cover	Grass Species Diversity	Declared Weed Species
      M24	50	2	1
      M25	100	5	1
      M26	90	4	1
      M27	100	4	0
      M28	100	4	0
      M29	90	2	0
      M30	90	1	0
      M31	100	6	0
      M32	100	4	0
      M33	100	3	1
      M34	100	5	0
      M35	100	3	0
      M36	100	4	1
      M37	90	4	0
      M38	100	5	0
      M39	100	4	0
      M40	100	4	0
      M41	80	3	0
      M42	100	2	0

      Soil Results

      Soil data for soil indicators for topsoil from each monitoring site are provided in Appendix 1. Soil laboratory results are provided in Appendix 6. As observed in previous monitoring rounds, soils sampled at rehabilitation monitoring sites show favourable pasture growth conditions. Sites with conditions outside target criteria are shown in blue in Table 9. It must be noted that these instances of non-conformance are not detrimental to plant growth and the criteria should be expanded to include these values (refer to Table 10). Sites with conditions outside target criteria which may be detrimental to plant growth are shown in red.

      Subsoils were also tested for each site in 2024.

      Electrical Conductivity (EC/se) is above the nominated criteria threshold at site M42. Although exceeding the listed threshold, There was little evidence this parameter is impacting pasture growth and no corrective action is recommended at this stage. If threshold is exceeded next year, and pasture species are restricted, recommended actions will be re-assessed.

      Total Organic Carbon (TOC) falls just below the nominated criteria threshold at sites M27 and M41.

      The EAT results of 7 indicate no slaking, but swelling of soil peds. This characteristic indicates the soil is very stable and not prone to slaking or dispersion, which is a very positive characteristic. No corrective action is recommended.

      ‌Table 9: Summary of Rehabilitation Sites Not Meeting Soil Property Criteria

      Site	Soil Texture	pH	pH	ECw	ECse	EAT	CEC	ESP	TOC	Cu	Zn	ERZ
      	Marshall	1:5w	CaCl2	µs/cm	µs/m		meq/100g	%	%	mg/kg	mg/kg	mm
      M24	Heavy Clay	8.0	7.1	190	1102	4.0	27.1	0.7	1.2	28.4	54.2	700
      M25	Clay Loam	8.1	7.4	190	1634	4.0	25.1	0.9	2.1	24.0	57.2	600
      M26	Clay Loam	7.9	7.0	160	1376	4.0	24.6	0.6	1.3	16.9	45.2	600
      M27	Medium Clay	8.2	7.5	170	1275	4.0	22.8	0.7	0.9	13.3	36.6	500
      M28	Light Clay	8.0	7.3	150	1290	7.0	24.2	0.8	2.1	20.2	59.2	900
      M29	Medium Clay	8.2	7.6	190	1425	4.0	28.5	0.9	2.0	19.6	48.6	500
      M30	Clay Loam	7.8	7.0	190	1634	4.0	23.7	0.7	1.5	23.1	51.0	600
      M31	Medium Clay	8.3	7.6	190	1425	4.0	29.0	1.3	1.2	20.9	57.8	500
      M32	Light Clay	7.9	7.1	170	1462	4.0	30.8	1.0	1.9	17.6	52.3	600
      M33	Medium Clay	8.3	7.5	210	1575	4.0	21.2	0.8	1.5	18.2	43.6	700
      M34	Medium Clay	7.9	7.0	160	1200	4.0	31.2	0.8	1.5	17.3	54.8	700
      M35	Heavy Clay	8.5	7.6	160	928	4.0	31.1	1.4	1.1	15.3	47.8	800
      M36	Clay Loam	8.0	7.2	170	1462	4.0	33.0	0.9	1.3	14.6	49.0	500
      M37	Clay Loam	8.5	7.7	200	1720	4.0	28.4	2.1	1.3	20.3	59.8	600
      M38	Light Clay	8.2	7.6	200	1720	4.0	36.0	1.0	2.0	16.4	48.4	550
      M39	Heavy Clay	7.9	7.0	170	986	4.0	32.6	1.2	1.4	16.2	51.9	900
      M40	Clay Loam	8.2	7.3	180	1548	4.0	35.8	1.1	1.5	14.8	57.3	500
      M41	Heavy Clay	7.8	7.0	190	1102	4.0	22.2	0.7	0.9	19.5	49.5	800
      M42	Clay Loam	8.6	7.9	250	2150	4.0	34.6	3.9	1.5	17.1	51.9	800

      Site Erosion, Slope & Geotechnical Stability

      The treatment of rehabilitation areas includes grading of overburden to a slope gradient of 20% (11.5 degrees) or less. The slope gradients of rehabilitation sites were all measured to be 15% or below over previous years. The change in RL measured at existing monitoring sites was found to be ≤0.8% which is likely representative of consolidation and should continue to be monitored. Full monitoring data for RL measurements are provided in Appendix 4.

      Similar to previous years no active erosion was observed at any of the monitoring sites, indicating that both the active and remediated erosion areas observed in the previous years' monitoring have now stabilised. Some evidence of rill and minor gully erosion was noted in the general rehabilitation area, however it is not necessary to nominate a repair program at this stage, as to repair these areas would require additional disturbance. Any observed rill or gully sites should be recorded and monitored.

2. ‌RE C O M M E ND AT I ON S

   The eleventh round of rehabilitation monitoring conducted during November 2024 shows the rehabilitation at NAC is continuing to progress toward its targets for grazing land use.

   Excellent pasture growth has occurred following good seasonal conditions for the last four years with both vegetation cover and pasture density considered very high with vegetation cover generally greater than 80%. Five

   (5) rehabilitation sites showed a declared weed to be present, however this can be managed by the continuation of weed control and treatment. In general, the rehabilitation monitoring sites show very favourable soil and pasture growth conditions. Continuation of the current rehabilitation methodology is strongly advised as results are excellent. Of note was the density of roots in the top 200mm of most soil profiles, as well as the strong crumb structure being developed due to the increasing organic matter and improving soil health.

   It is recommended that the vegetation and soil criteria indicators developed in 2018 (with minor modifications as recommended below) continue to be assessed in subsequent years to maintain a consistent monitoring dataset. General observations of declared weeds and erosion should be made across the rehabilitation areas to address limitations with spatial distribution of monitoring sites.

   A summary of Minesoils recommendations are shown in Table 10.

   Table 10: Summary of Recommendations

   Category	Recommendation
   Weeds	Continue weed control program for existing and new weed infestations in rehabilitation areas, continued targeting of African Boxthorn, Pear species and Cotton Bush, Turnip Weed, Roly Poly, Acacia species and other less dominant weeds. Future grazing may assist with further weed control.
   Analogue Sites	Minesoils has established new analogue sites in the Stage 3 project area and recommends these be used for future monitoring criteria. This will allow for variability within the rehabilitation soil profiles, whilst meeting land capability targets. Currently there are 19 rehabilitation and only four analogue sites three of which are considered unsuitable. The addition of more suitable analogue sites for better data comparison is recommended. Analogue sites R01, R02 and R04 have very little comparison value as neither are representative of the landform being mined or being rehabilitated. It is recommended to cease monitoring these sites.
   Monitoring Time	Undertake monitoring during autumn-winter and spring-summer alternate years. This will provide a year-round comparison of present pasture and weed species.
   LIDAR	Fly a full LIDAR set across all rehabilitated areas to monitor for subsidence.
   Soil Testing	Increase testing suite to include Colwell phosphorus, nitrate nitrogen and plant available sulfur once grazing commences. Test subsoil samples every 2nd or 3rd year.
   Grazing Rehabilitation	There is opportunity to fence and crash graze some large areas of previously ungrazed rehabilitation to remove dry matter and encourage new grass and vetch growth. There is a lot of feed in these areas and the increasing size is making it viable for fencing and grazing. Thorough planning for permanent fencing and water systems is required.
   Modify Target Criteria	Modify Target criteria to include favourable measurements: Geotechnical stability - Stabilised surface and ground. No active detrimental subsidence. (Justification: achieving 'no subsidence' on overburden dumps is an unrealistic target, so allowing for minor subsidence, ensuring it is not detrimental to grazing land use or is triggering erosion is more pragmatic). Emerson Aggregate Test - Class 2(1) or 3 - 8 (Justification: Class 2(2) and 2(3) are considered unstable with high to very high dispersibility. Class 2(1) is borderline with moderate to high dispersibility and susceptibility to erosion. On the other end, Class 7 and 8 should be included within the criteria as these are very stable soil peds with no slaking) Depth of effective Root Zone - >250mm (Justification: There should be no depth limit of lower root zone depth. It has been observed that the weathering overburden is starting to function as a growth media and it is expected that over time roots will penetrate deep into the overburden) Electrical Conductivity (ECw) - <240uS/cm for sandy soils; and <300uS/cm for clay soils. (Justification - it is unclear why there should be a lower limit for salinity. An upper limit is adequate for target criteria) Cation Exchange Capacity (CEC) - >9 meq/100gm (Justification - There is no reason to place an upper limit threshold on CEC. As the organic matter and humus increase with soil health in the high clay content soils, values greater than 45 meq/100gm will be common, and is not detrimental to a grazing landuse)
   Install Tracks	Install access tracks throughout the rehabilitation with major all-weather main tracks and slashed-only minor tracks for easy access for monitoring, inspections and maintenance.

3. ‌RE F E RE N CE S

Bureau of Meteorology (2025). Climate statistics for Australian locations, Oakey Airport (Station 41359) Australian Government. Accessed 11th February 2025 Climate statistics for Australian locations (bom.gov.au)

Elliot, G.L. and Reynolds, K.C. in Charman, P.E.V. and Murphy, B.W. (2007) Soils their Properties and Management

(Oxford University Press, Australia).

Hazelton, P.A. and Murphy, B.W. (2011) Interpreting Soil Test Results - What do all the numbers mean? CSIRO Publishing Collingwood VIC.

Isbell, R. F. (2021) The Australian Soil Classification Third Edition (CSIRO Publication, Australia).

McKenzie, N.J, Grundy, M.J., Webster, R. and Ringrose-Voase, A.J. (2008) Guidelines for Surveying Soil and Land Resources (2nd Ed). CSIRO Publishing, Melbourne.

Minesoils (2023) New Acland Coal Mine -Rehabilitation Monitoring 2023.

National Committee on Soil and Terrain (NCST) (2009) Australian Soil and Land Survey Field Handbook, 3rd edition (CSIRO, Australia).

SLR (2022) 2022 Rehabilitation Monitoring Program - New Acland Coal Mine.

Table A1.1: Analogue Site Soil Results (Most recent testing undertaken in 2023)

New Acland Coal Mine - Rehabilitation Monitoring 2024

MS-175_ Final June 2025

pg. 24

New Acland Coal Mine - Rehabilitation Monitoring 2024

MS-175_ Final June 2025

pg. 25

Table A3.1 Analogue Site Comparative Monitoring

Table A3.2 Analogue Site Comparative Monitoring

Table A3.3 Analogue Site Comparative Monitoring

Table A3.4 Rehabilitation Site Comparative Monitoring