June 27, 2016 Toro Energy Ltd Level 3, 33 Richardson Street 6005 … · 1 Millipede / Centipede...

Status: Draft Response Project No.: 83502571 Our ref: MWH Response OEPA Info Request Sub Fauna V1-1 20160627

June 27, 2016 Toro Energy Ltd Level 3, 33 Richardson Street West Perth, Western Australia 6005

Wiluna Extension Uranium Project: MWH responses to OEPA’s request for additional information regarding subterranean fauna

Attention: Richard Yeeles Approvals and Community Director Dear Richard, The purpose of this letter is to provide additional information to address actioned items that were raised in

meetings held on Thursday the 9th of June, 2016 among representatives for Toro Energy (Toro) and the

Western Australian Office of the Environmental Protection Authority (OEPA) that I also attended,

concerning the Wiluna Extension Uranium Project PER and subterranean fauna. The actioned items that

the OEPA requested be further addressed were:

1. Millipede / Centipede Project area — Provide greater clarity illustrating the additional extent of the

Hinkler Well PEC that will fall within the modelled 0.5 m below natural standing water level (bSWL)

groundwater drawdown impact contour proposed in the Wiluna Extension Uranium Project PER

compared to the previous modelled 0.5 bSWL drawdown impact contour that was approved for the

development of the Centipede deposit (Ministerial Statement No: 913; EBBC 2009/5174).

2. Physical and biological surrogacy — Provide additional information to add further support for

conclusions reached that currently restricted stygofauna species are likely to possess broader

distributions than demonstrated as a result of extents of habitat/s present, and distributions and

habitat preferences/tolerances of other stygofauna species.

3. Reinjection at Lake Maitland — Provide succinct evaluation of potential impacts to troglofauna

posed by the proposed groundwater reinjection scheme in and around the Lake Maitland playa to

manage water from mine pit dewatering that may be surplus to reuse in the operational water

supply at various stages of the Project.

Yours sincerely Dr Nicholas Stevens Principal Environmental Scientist Subterranean Fauna Technical Lead

MWH, now part of Stantec. Please visit www.stantec.com to learn more about how Stantec designs with community in mind.

http://www.stantec.com/


1 Millipede / Centipede Project area — Illustration of the additional extent of the Hinkler Well PEC that will fall within the modelled 0.5 m bSWL groundwater drawdown impact contour proposed in the Wiluna Extension Uranium Project PER compared to the previous modelled 0.5 bSWL drawdown impact contour that was approved for the development of the Centipede deposit (Ministerial Statement No: 913; EBBC 2009/5174).

The total lateral expanse of area proposed to be impacted by the proposed lowering of the groundwater

table by greater than 0.5m bSWL (with no mitigation barriers installed) associated with dewatering of

proposed Millipede/Centipede mine pits will be 5,904 Ha (Table 1-1, Figures 1-1 and 2). The total area

of the Hinkler Well calcrete PEC that will be impacted by the proposed groundwater drawdown will be

1328 ha, representing 17.5% of the total inferred PEC area of 7572.6 ha. The previously approved

extent of groundwater drawdown associated with the proposed dewatering of the Centipede pit mining

panels only represented a total area 4,460 Ha, potentially impacting 1,160 Ha (15.3%) of the inferred

PEC boundary. The recently proposed drawdown associated with the dewatering of the

Millipede/Centipede deposits represents a 168 Ha (2.2%) increase in area of the PEC impacted

(Figures 1-1 and 2; area shaded red). The proposed drawdown within the additional PEC area

impacted will be 0.5 to 1 m bSWL. The proposed increase in area of drawdown will encompass the

Abercromby pastoral well from which only the widely distributed copepod Metacyclops laurentiisae was

recorded.

An important point to reiterate regarding the groundwater drawdown is that the modelled 0.5 m bSWL

contour represents the combined lateral extent of the individual drawdowns associated with each mining

panel within both the Millipede and Centipede deposits as they are successively excavated; i.e. the area

within the modelled 0.5 m bSWL groundwater drawdown contour will experience a drawdown as a result

of successive dewatering of each mine panel, however, the drawdown will not occur simultaneously to

the extent of the modelled 0.5 m bSWL drawdown contour. The proposed mining schedule will mean

that the modelled 0.5 m bSWL groundwater contour associated with each mining panel as they are

successively excavated will represent a subset of the depicted maximal extent of groundwater

drawdown impact.

Table 1-1:

Total Area (Ha)

PEC Area (Ha)

% of total PEC area

Total Area (Ha)

PEC Area (Ha)

% of total PEC area

Additional Area (Ha)

% of additional PEC area

7573 4460 1160 15.3 5904 1328 17.5 168 2.2

Approved Area of Impact Total Area Hinkler Well Calcrete PEC

(exc buffers; Ha)

Proposed Area of Impact


Figure 1-1: Millipede/Centipede (Hinkler Well calcrete) Project area — Comparison between extents of approved mine pit dewatering groundwater drawdown (Centipede pit only) and proposed additional groundwater drawdown (Millipede and Centipede pits).

Status: Draft Project No.: 83502571 Our ref: MWH Response OEPA Info Request Sub Fauna V1-1 20160627

Figure 1-2: Millipede/Centipede (Hinkler Well calcrete) Project area — Closer look at extent of Hinkler Well PEC that falls outside previously approved groundwater drawdown and within proposed additional groundwater drawdown.


2 Physical and biological surrogacy — Provide additional information to further support conclusions reached that currently restricted species are likely to possess broader distributions than demonstrated as a result of extents of habitat/s present, and distributions and habitat preferences/tolerances of other stygofauna taxa.

2.1 Introduction

It is not possible to reliably assess the distribution range of stygofauna species that are known only from

limited records. Sampling the full extent of their likely range is often not possible as access to the

subterranean habitat can often be constrained by the lack of bores available. Ecologically, there are

many factors that influence the distribution of stygofauna at a range of habitat and temporal scales

(Boulton 2000). Some of the more influential factors at the microhabitat (sediment) scale include

suitable interstitial pore size (i.e. provision of connected network of habitable cavities), inflow rates of

energy resources (e.g. organic carbon, biofilm growth, prey), and water quality parameters such as

water temperature, pH, dissolved oxygen and organic carbon levels. At the mesohabitat (catchment)

scale, factors include flow patterns along a water course influencing zones of upwelling and downwelling

of energy resources or dissolved oxygen according to geomorphological features, as well as interactions

with riparian and parafluvial sediments (Boulton et al. 1998). In addition, there are temporal variations

in assemblage diversity when sampling as demonstrated with the continuation of the discovery of new

species from previously relatively well sample areas (Guzik et al. 2010) or species only recorded

intermittently over the course of an extensive survey program (Karanovic and Cooper 2012, MWH

2015). The seemingly restricted distribution of a taxon to a single bore, may likely be an artefact of

sampling a species occurring at low population densities with a patchy, irregular distribution within the

aquifer in response to varying micro- and mesohabitat factors, seasonality, biological interactions and

availability of energy resources, rather than the actual distribution being confined to one limited area

that was intercepted by a single bore.

Biological and physical surrogates can assist in determining likely species distributions and addressing

the artefact of sampling difficulties associated with subterranean fauna as recommended by

Environmental Protection Authority (2013). Considering the expanse of neighbouring geological habitat

(physical surrogate) as well as reviewing records of closely-related species, or species collected

sympatrically (biological surrogates), can provide further insight into the potential distribution patterns of

species that are known from a few records only.

Molecular studies of subterranean species have demonstrated that the use of physical and biological

surrogates is a valid approach to assessing the potential distribution of a species known from a single

specimen or bore location. Investigations of population structure of stygofauna species in the Sturt

Meadows and Laverton Downs calcrete systems indicated that similar trends in distribution patterns at

the species and population levels existed amongst sympatric species of the same order as well as of

different orders, with linear ranges in the Laverton Downs calcrete shown to extend for as great as 15

km for amphipod, beetle and isopod species (Bradford et al. 2013, Guzik et al. 2011). Of particular

interest from these and other stygofauna molecular studies is that the majority of stygofauna species


studied within a calcrete system have been shown to have evolved from independent colonisation by

epigean (surface) ancestors and not from allopatric speciation of a stygofauna ancestor; i.e. the

populations of a species within a calcrete system have not become isolated from each other such that

gene flow has ceased to an extent that populations have diverged into separate species (Cooper et al.

2007, Cooper et al. 2002, Cooper et al. 2008, Guzik et al. 2008, Guzik et al. 2011, Karanovic and

Cooper 2011, Karanovic and Cooper 2012, Leijs et al. 2003). Instead, the haplotype diversity found to

be present did indicate that the aquifer environment has been relatively dynamic with many fluctuations

in groundwater levels and resource recharge over the past few million years with water table levels likely

to have been much lower during glacial periods than they are at present (Guzik et al. 2011).

Previous risk assessments concluded that the proposed development of the Centipede mining area and

associated groundwater drawdown and infrastructure did not pose a long term conservation risk to any

species of the Hinkler Well calcrete stygofauna priority ecological community (Outback Ecology 2011,

2012c). These conclusions were based upon the greater extent of more suitable contiguous habitat

known to be present outside of the proposed impact zones. Suitability and connectedness of this

habitat was demonstrated by the broader distributions of the majority of subterranean fauna species

recorded, as well as by geological and hydrogeological assessments. The 2015 Millipede targeted

survey demonstrated these conclusions to be valid, with the demonstrated broader distribution of

Schizopera sp. TK7 that had previously been found only from within the proposed Centipede pit area.

This further confirmed the usefulness of biological surrogates (e.g. sympatric and/or closely related

species) and physical surrogates (e.g. habitat from geology, hydrogeology and groundwater

physicochemical attributes) to assess likely distributions.

Further biological and physical surrogate information, including more in-depth analysis will be presented

here to provide additional support of the environmental impact assessments (EIA) made in the 2016

PER (Toro Energy Limited 2015) and relevant technical reports (MWH 2015, Outback Ecology 2011,

2012c) and subsequent responses to comments received (MWH 2016a, b). More specifically, the

additional information and analysis will focus on the stygofauna species recorded only from within the

proposed mining excavation impact areas:

Millipede pit — the amphipod Chiltoniidae-SAM6; and

Lake Maitland pits — Chiltoniidae sp. SAM4 and Schizopera sp. TK1.

2.2 Recent reassessment of subterranean habitats occurring in proposed mining areas - The previous interpretation of the geology associated with the Millipede / Centipede and Lake Maitland

uranium deposit areas has recently undergone further refinement (Toro Energy Limited 2016). The

interpretation of bore lithologies, based on the sedimentary host and respective grain size fraction

analysis, derived from the sonic core drilling programs undertaken recently have provided a more

reliable resolution of the geological strata present compared to the previous air core drilled samples that

the historical geology models were derived from. A recommendation of the new geological model is that

the ‘calcrete hosted uranium deposits’ be referred to more accurately as ‘shallow groundwater

carbonate associated uranium deposits’ (Toro Energy Limited 2016).


The geological re-interpretation is an ongoing process but the essence of the findings to date that relate

moreso to the refinement of subterranean habitats present are that limited concretion of carbonate

minerals (i.e. ‘calcrete’) exists within the Millipede / Centipede uranium deposits with little to none

present within the Lake Maitland deposit areas (Appendix A: Figures A-1 and 2; Appendix B: Figures B-1 to 4) (Toro Energy Limited 2016). The ‘calcrete’ facies indicated previously in transects of

the Centipede deposit area have been found to be over represented (Figure A-2 compared to A-3).

Although small, thin, discontinuous pods of ‘calcrete’ are considered to occur in and around the

proposed Millipede / Centipede mining areas, most of what was previously logged as ‘calcrete’ has

since been found to be mostly representative of ‘semi-consolidated carbonate / silica with clay’, or ‘fine

grained sediments with minor concretions of carbonate and silica’, or ‘clay sediment’.

For the Lake Maitland deposit the historical geological model showed that the high grade uranium

mineralisation had mostly occurred within the ‘calcrete’ unit (Figure B-1) (Toro Energy Limited 2016).

However, the re-interpretation of the geology associated with the deposit areas found that the high

grade uranium mineralisation was mostly within the underlying clay unit with only thin (20 to 50 cm)

intermittent lenses of semi-consolidated carbonate concretions (Figures B-1 and 2).

The finer resolution of geological mapping undertaken to date has shown that within the Millipede /

Centipede and Lake Maitland deposit areas there is considerably less prospective habitat for stygofauna

than what was previously thought. The historical modelling had always indicated that the habitat within

each deposit area was less prospective, with thin, intermittent calcrete lenses hosted within highly saline

conditions, compared to further westward up each calcrete system where more extensive (vertically and

laterally) and contiguous calcrete had developed in association with fresh groundwater conditions

(Dundon 1997, RPS Aquaterra 2010a). Core images indicate that the limited prospective stygofauna

habitat present in the deposit areas would more likely be associated with the coarser saturated

sediments such as the semi-consolidated carbonate / silcrete (Figure A-3 and Figure B-5). The finer

grain clay and sand sediments would not be considered prospective stygofauna habitat as there is not

sufficient interstitial pore space present to enable colonisation.

The geology is more complex at Millipede / Centipede deposits with a thicker, more prominent semi-

consolidated carbonate/silica unit inter woven with lenses of sands, silt sand clays (Figure A-1),

compared to Lake Maitland deposit. Lake Maitland deposit tends to be dominated by a relatively thick,

flat, and consistent clay unit (Figure B-2). These differences are attributed to the varying depositional

environments with the Millipede / Centipede deposits characteristic of a higher energy flow deltaic

environment and Lake Maitland deposit characteristic of a lower energy flow lacustrine environment.

The geological interpretation of the deposition of each deposit area appears relatively consistent with

stygofauna survey results. Bores sampled within lower lying areas close to or on the lake playas that

are more dominated by clay and silt sedimentation, were less likely to host stygofauna compared to

bores further up from the playa shoreline and on the main calcrete body of each system where greater

extent of habitable units occur (Figure C-1 and Figure D-1 and 2).


2.1 Proposed Millipede Pit — Chiltoniidae-SAM6

The removal of habitat through mining excavation poses a conservation risk to one of the eight

stygofauna species recorded from within the proposed Millipede pit boundary, the amphipod,

Chiltoniidae-SAM6. The proposed Millipede pits all fall within the previously approved deeper

groundwater drawdown impact zones associated with the Centipede pit (refer Section 1, Figure 1-1 and 2).

Recorded Habitat

Chiltoniidae-SAM6 was recorded from two Millipede bores only, Gt12 and Gt1-A, for which the bore

lithologies are not known (Figure C-2). The interpreted geology from sonic bore cores near each of

Chiltoniidae-SAM6’s recorded locations indicate that there is likely to be limited habitat, such as semi-

consolidated carbonates/silicas present with the dominant units in the general area consisting mostly of

clay with interspersed sand and silt lenses (Figure A-2). Core lithologies (from 0 to 9 m bGL) of sonic

bores WS153 and WS152 located near Gt12, that is less than 80 m from the approved Centipede pit

boundary, indicate that fine grain clay units begin at around 2 m bGL (Figure A-3). The SWL recorded

at Gt12 in January 2015 was 2.15 m bGL. Moving further west to within the central part of the proposed

Millipede pit, core lithologies (from 0 to 9 m bGL) of sonic bores WS169 and WS170 located near Gt1-A,

have coarser grained semi-consolidated carbonate/silica starting from around 3 m bGL and extending to

varying depths of 4 to 6 m bGL (Figure A-3). The SWL recorded at Gt1-A in January 2015 was 3.15 m

bGL. The core logs further support the model that limited saturated habitable units are present in the

deposit areas. They also suggest that the habitable units most likely present exist as inter-laced fingers

of semi-consolidated carbonate/silica, with possibly limited coarse sands/gravels, that have evolved

within the braided deltaic depositional environment. Consistent with the prevailing historical surface

flow direction from west to east along the paleochannel of the deltaic depositional environment, these

habitable units become more prominent heading westwards away from the lake playa towards the main

calcrete unit to the west of the deposit areas (Figure A-3).

The geological and hydrogeological assessments of the Hinkler Well calcrete system indicate that the

Millipede deposit has formed as part of the same hydrogeological aquifer system as the Centipede

deposit. Both deposits are hosted within a broader deltaic depositional setting that has evolved as part

of the historical inflow of the Abercromby Creek, and to a lesser extent Centipede Creek, into the Lake

Way system. Within the eastern portion of the Hinkler Well calcrete system it is not known with certainty

where the boundary between the more expansive calcrete habitat and braided tendrils of the more

prominent semi-consolidated carbonate/silica occurs. East of the Erawalla fault the calcrete fans out

and broadens in profile varying from 5 m to 19 m thick between the Goldfields Highway and Abercromby

Well (RPS Aquaterra 2010a). Known lithologies of bores NLW9 and NLW11, indicate that the calcrete

extends from the surface to approximately 7.5 m bGL with saturated habitable profiles ranging from 2.7

to 4.7 m thick (Figure C-2, Table A-1). Further to the north of NLW9 and NLW11 the lithologies for

bores NLW22 and NLW23 indicate that the calcrete only extends from the surface to 4.5 m bgl with the

saturated profile ranging from 0.1 to 1 m thick (Table A-1). At NLW20, approximately 700 m to the

north of NLW9 and NLW11, no calcrete was recorded with the sand facies present extending for greater

than 10 m bgl to the bottom of the bore (Table A-1).


For the Hinkler Well calcrete system, salinities tend to decrease with distance from the playa, the lowest

values generally recorded from bores located further west of the Goldfields Highway. The thickness of

the freshwater stratum ranged from greater than 24 m at bore SB26-1, approximately 20 kms from the

lake playa to less than 1 m at NVCT074A approximately 1.5 km from the lake playa (MWH 2015).

Below the thin freshwater layer at NVCT074A, was a thin hyposaline (15 ppt) layer that was at least 1 m

thick, before the groundwater became hypersaline (62 ppt) at 3 m below standing water level (bSWL)

with salinity more than doubling to 735 ppt at 6 m bSWL. Closer to the lake playa, at CENTOES51 for

example, the upper stratum was hypersaline ranging from 122 ppt at 0 m bSWL to 182 ppt at 14 m

bSWL.

Groundwater parameters recorded from the Millipede deposit bores in 2015 followed a simila r trend with

salinity levels in the northern part of the deposit ranging from freshwater to mesosaline (11 ppt at

MAC08, 32.2 ppt at Gt12, up to 46 ppt at Gt1-A) just beneath the surface of the standing water column

and becoming hypersaline conditions (> 80 ppt) within 2 mSWL. The groundwater was more saline in

the southern Millipede deposit near the playa inlet with salinity levels exceeding 57 ppt at MPD-1P1 just

below the water column surface and in excess of 95 ppt at 2 mbSWL.

The shallow habitable geological units interpreted to be present in the Millipede deposit area from which

Chiltoniidae-SAM6 was recorded, coupled with the hypersaline groundwater conditions present within 2

m bSWL, indicate that the deposit area is not likely to host a vertically extensive habitat. Instead, it is

considered more likely that this less optimal inhabited environment represents the periphery of the

distribution range of Chiltoniidae-SAM6.

Recorded distribution patterns

Stygobitic chiltoniid amphipod species have been relatively commonly recorded from many of the

northern Yilgarn calcretes sampled (Bradford et al. 2013, Bradford et al. 2010, Cooper et al. 2007, Guzik

et al. 2011, Subterranean Ecology 2011). Studies that have involved repeated sample rounds, coupled

with a reasonable geographic survey coverage of a particular calcrete system have found amphipod

species richness have not exceeded three species (e.g., Bradford et al. 2013b, Bradford et al. 2010,

Guzik et al. 2011, Subterranean Ecology 2011), a similar pattern found with stygobitic diving beetles

(Leijs et al. 2003, Watts and Humphreys 2006, 2009). In addition, molecular phylogenetic analyses

have revealed within these well studied calcrete systems (e.g. Laverton Downs, Sturt Meadows, and

Yeelirrie) recorded amphipod species were broadly distributed (Bradford et al. 2013b, Guzik et al. 2011,

Subterranean Ecology 2011).

Molecular evidence revealed that the Laveton Downs calcrete and Yeelirrie calcrete systems each

hosted an undescribed amphipod species with each species possing a relatively wide distribution.

Within the Laveton Downs calcrete a 15 km region of the 25 km long aquifer system (90 km2 in area)

was sampled (Guzik et al. 2011). The single chiltoniid species present was found to be distr ibuted

throughout the 15 km long survey area despite the presence of a salt lake system, whose partial

encroachment between northern and southern sample sites had previously been considered to


represent a potential geographical barrier. The relatively widspread distrution of the amphipod species

was also displayed by other examined stygofauna species in the Laveton Downs calcrete assemblage

that included three diving beetle species and an isopod (Guzik et al. 2011).

The single chiltoniid species commonly recorded from the Yeelirrie calcrete system was shown to have

a distribution that ranged for approximately 70 km from the most north-western survey line (P) down

through many of the Yeelirrie calcretes to the south-east of the Yeelirrie salt lake playa (Subterranean

Ecology 2011). This may represent one of the broadest distributions recorded from a stygobitic

amphipod in the Yilgarn or Pilbara regions. The molecular analysis did reveal a relativley high

haplotype diversity present and suggested that there is likely to be a degree of gene flow restriction

between geographically distant populations (Finston and Berry (2011) in Subterranean Ecology 2011).

At Sturt Meadows, the three amphipod species present were each recorded across the surveyed

geographical range, that consisted of more than 100 bores arranged in a grid over a 3.5 km2 area, and

displayed broadly overlapping (largely sympatric) distributions (Bradford et al. 2013b). The Sturt

Meadows survey grid was located more than 7 kms from the Lake Raeside playa, within the main

calcrete unit where lithology zones ranged from calcrete greater than 11 m thick to less than 3 m thick

and overlying clay. All three species were recorded from all designated lithology zones including two

designated zones (A5 = calcrete (thickness not specified) underlying a 4 to 6 m thick clay layer; and C-D

= clay with some calcrete) that would be considered to represent less prospective habitat .

The chiltoniid species, Chiltoniidae sp. SAM1, collected from the Lake Violet and Uramurdah calcrete

systems was demonstrated to possess a relatively widespread distribution (Outback Ecology 2012c).

The distribution of Chiltoniidae sp. SAM1 was found to extend from the Lake Violet and Uramurdah

calcrete systems for more than 30 km to the north-west to Millbillillie Bubble Well calcrete This species

also displayed a tolerance for varying groundwater conditions from saline to freshwater conditions.

Within the Hinkler Well calcrete system the Chiltoniidae-SAM3 is widely distributed (MWH 2015,

Outback Ecology 2011, 2012c). The geographical range of Chiltoniidae-SAM3 extends from the

mesosaline to hypersaline groundwater conditions within the Centipede deposit area to more than 18

km to the west in freshwater conditions within the western portion of the calcrete system beyond the

Erawalla fault uplift.

Chiltoniidae-SAM6 is closely related to Chiltoniidae-SAM3 displaying a 8.9 to 9.5 % genetic divergence.

Chiltoniidae-SAM6 was collected from mesosaline groundwater conditions that became hypersaline at

two metres depth. Chiltoniidae-SAM6 is considered likely to display a similar tolerance to varying

groundwater salinity levels and broader distribution range as displayed by other closely related chiltoniid

species also from Lake Way associated calcrete systems.

Intra-specific (within species) genetic variation displayed between the two specimens of Chiltoniidae-

SAM6 sequenced was 1.2% which was marginally greater than that displayed for the more commonly

collected Chiltoniidae-SAM3 with 1.1%. The co-occurrence of a higher level of haplotype diversity


among specimens collected within a limited geographical area is considered to be an indication of a

relatively large and more widespread population than location records may show (Guzik et al. 2011).

Chiltoniidae-SAM6 was collected sympatrically with four other stygofauna species, Atopobathynella

wattsi, Fierscyclops fiersi, Halicyclops eberhardi, Nitokra sp. TK1, and Nitokra sp. TK2, all of which

possess distributions that extend beyond the Millipede deposit into the broader Hinkler Well calcrete

(Figures C-3, 5 and 6). The broader distributions of the sympatric species recorded does indicate that

the aquifer sampled within the Millipede deposit is connected to, and forms part of the broader aquifer

system associated with the Hinkler Well calcrete system (i.e. the groundwater associated with the

Millipede deposit is not an isolated aquifer) which is consistent with the hydrogeological evidence.

Likely distribution range

It is considered unlikely that the distribution of Chiltoniidae-SAM6 is confined to the Millipede deposit

area and associated modelled groundwater drawdown contours when taking into account the physical

and biological evidence presented above that demonstrates the presence of suitable and connected

habitat beyond the proposed Millipede pit areas; the high likelihood that Chiltoniidae-SAM6 does

possess a relatively widespread distribution as exhibited by other chiltoniid species recorded from other

Yilgarn calcretes, including Lake Way associated calcrete systems; and is able to tolerate varying

groundwater salinities as also exhibited by other chiltoniid species recorded from other Yilgarn calcretes

including Lake Way associated calcrete systems.


2.2 Proposed Lake Maitland Pits —Chiltoniidae sp. SAM4 and Schizopera sp. TK1.

The removal of habitat through mining excavation poses a conservation risk to two of the ten stygofauna

species recorded from within the proposed Lake Maitland pits, Chiltoniidae sp. SAM4 and Schizopera sp.

TK1.

Recorded Habitat

Chiltoniidae sp. SAM4 is known from three specimens collected in March, 2010 from bore EH01, the only

time the bore was sampled (Figure D-3). Bore EH01 is located south of the surface expression of the

Barwidgee calcrete within the lower lying areas fringing the lake playa where groundwater salinity levels

present in the upper stratum of the water column of the bore were hypersaline (105.9 mS/cm). The low

lying environment fringing the lake playa is relatively extensive and consists at the surface of clays/silts with

a salt crust.

The bore lithology for EH01 is not known. The interpreted geology derived from sonic bore cores near

Chiltoniidae sp. SAM4’s recorded location indicate that there is likely to be limited habitat present such as

semi-consolidated carbonates/silicas, in the low lying areas near the Lake Maitland playa, with the

dominant units consisting mostly of clay underlying a sandy clay surface with clayey sands, underlain by

gravels, present to the south (Figure B-5: sections 3 and 4). The more prospective semi-consolidated

carbonates/silicas habitat appears to occur more persistently as the main Barwidgee calcrete body is

approached. The known lithology (from 0 to 7 m bGL) of bore LMDD0253 (Figure B-5), 400 m to the north-

west of EH01 (Figure D-3) recorded semi-consolidated carbonates/silicas within the upper 1 to 2 m bGL

with coarse sand and limited gravel occurring from 4.5 to 7 m bGL interspersed with some finer grained

silts/clays. The SWL recorded at EH01 in March 2010 was 2.3 m bGL. Further to the north-west of EH01,

calcrete was expressed at the surface at bore BH10 (RPS Aquaterra 2010b). The surface calcrete layer

extended to 4 m bgl with the standing water level occurring at 2.84 m bgl resulting in 1.16 m of saturated

calcrete (RPS Aquaterra 2010b). At EH01, a thin persistent layer, less than 1 m in thickness, of semi-

consolidated carbonates/silicas (referred to previously in Outback Ecology (2012a) as brown

gypcrete/brecciated calcrete) that is fractured and sometimes vuggy, was observed to be present

approximately 2 m bgl with an underlying layer of low permeable clay (RPS Aquaterra 2010b).

The distribution of Schizopera sp. TK1 is known to extend for over 10 km from the northern resource area

down to the southern resource area (Figure D-5). Six specimens of Schizopera sp. TK1 were collected in

May, 2007 from bores LMAC0352 and LMAC0448, and in March, 2010 from bore EH01. Only bore

LMAC0352 was sampled on one further occasion in 2008, but no additional specimens were collected. All

three bores occur within the lower lying areas fringing or on the lake playa where groundwater salinity levels

present in the upper stratum of the water column of each bore was hypersaline with values ranging from

105.9 to 132.3mS/cm (Outback Ecology 2012a). The salinity levels other more widely distributed

Schizopera species have been recorded from in this study as well as from Lake Way (Outback Ecology

2011) have ranged from hyposaline to hypersaline conditions.

The habitat likely to be present in the vicinity of EH01 is discussed above. The lithologies for bores

LMAC0352 and LMAC0448, derived from air core drilling had previously indicated that Schizopera sp. TK1


was not confined to ‘calcrete’ habitat only. For LMAC0352, no ‘calcrete’ was logged as present with the

saturated strata present consisting mostly of clay that was overlain by a thin saturated prospective habitable

layer of semi-consolidated carbonate/silica (originally logged as clay and ferricrete) (Table B-1). Core

lithologies (from 0 to 5 m bGL) of sonic bores LMDD0084 located near LMAC0352 (Figure D-5), recorded

semi-consolidated carbonates/silicas within the upper 1.75 m bGL with coarse sand and limited gravel

occurring from 2.25 to 4 m bGL interspersed with some thin finer grained silt/clay layers (Figure B-5). For

LMAC0448, approximately 1 to 1.4 m of prospective habitat consisting of semi-consolidated

carbonate/silica (originally logged as saturated ‘calcrete’ and calcrete+clay) was recorded. Core lithologies

(from 0 to 5.7 m bGL) of the closest sonic bores (LMDD0078 and LMDD0082) to LMAC0448, approximately

2.25 km to the south-east, from similar surface habitat (Figure D-5), recorded thicker semi-consolidated

carbonates/silicas within the upper 5 m bGL overlain and interspersed with thin thin finer grained silt/clay

layers (Figure B-5).

The recorded saturated habitats for both Chiltoniidae sp. SAM4 and Schizopera sp. TK1 from the Lake

Maitland deposit areas are dominated by clay layers with only thin prospective habitable layers

interspersed in the upper few metres only in highly saline groundwater environment. The formation of

the Lake Maitland deposit within a lower energy flow lacustrine environment is not considered to host

extensive prospective stygofauna habitat. However, the limited habitat demonstrated to be present is

considered to be hydrogeologically connected to the broader Barwidgee calcrete system that extends

from the Lake Maitland playa for more than 15 kms to the north-west (Golder Associates 2011).

The shallow habitable geological units interpreted to be present in the Lake Maitland deposit area from

which both Chiltoniidae sp. SAM4 and Schizopera sp. TK1 were recorded, coupled with the hypersaline

groundwater conditions present, indicate that the deposit area is not likely to host a vertically extensive

habitat. Instead, it is considered more likely that this less optimal inhabited environment represents the

periphery of the distribution range for both species, particularly for Chiltoniidae sp. SAM4. For

Schizopera sp. TK1, it is possible that habitable conditions exist throughout much of the Lake Maitland

playa system that extends southward for approximately 25 km from the northern deposit area (Figure B-6).

Recorded distribution patterns

Chiltoniidae sp. SAM4

The broader distribution patterns demonstrated by molecular investigations of stygobitic chiltoniids in

the Yilgarn calcrete systems is discussed above in Section 2.1. Adding to that discussion are the

findings of the amphipod genetic studies undertaken at Lake Maitland (Outback Ecology 2012a). The

phylogenetic analysis of the CO1 gene fragment sequenced showed the intraspecific (within species)

genetic divergence between the two Chiltoniidae sp. SAM4 specimens that were collected in the same

sample was 2.4 % (Leijs (2011) in Outback Ecology 2012a). This high haplotype divergence was

greater than that displayed for the more commonly collected and widely distributed Chiltoniidae sp.

OES1 within the Barwidgee calcrete system. The co-occurrence of a higher level of haplotype diversity

among specimens collected within a limited geographical area is considered to be an indication of a

relatively large and more widespread population than location records may show (Guzik et al. 2011).


Chiltoniidae sp. OES1 was morphologically and genetically distinct (13.8 to 14.9 % divergence shown) from

Chiltoniidae sp. SAM4 and was shown to be distributed throughout the Barwidgee calcrete, ranging from

near the Lake Maitland resource area to more than 10 km westward up the main calcrete system.

Chiltoniidae sp. OES1 existed in groundwater environments that ranged in salinities from hyposaline to

mesosaline. The scenario of the amphipods recorded form Lake Maitland is analogous to the Lake Way

associated calcretes, where chiltoniid species have been confirmed by molecular analysis to be relatively

widespread and to also exist within a broad range of groundwater salinity levels (Outback Ecology 2011).

The data collated from these studies indicate that, although chiltoniid species can tolerate hypersaline

environments near to salt lake playas where the extent of habitat may be limited, the preferred

environments where species were more commonly collected are less saline conditions within more calcrete

dominated geologies.

Four other species of stygofauna collected sympatrically with Chiltoniidae sp. SAM4 from Bore EH01,

Halicyclops sp. TK1, Halicyclops sp. TK2, Nitokra lacustris pacifica, and Nitokra sp. TK3, were also

recorded from bores outside of the Mining operations impact areas with ranges extending more broadly

westwards within the Barwidgee calcrete. The broader distributions of these four species does indicate that

the habitat present at Bore EH01 does not represent an isolated aquifer system but instead is connected

with contiguous habitable saturated geologies that extend beyond the Lake Maitland mining operations

impact areas from along the margins of the northern lake playa system further westward up the Barwidgee

calcrete system to beyond Little Well.

Schizopera sp. TK1

Schizopera species have been commonly collected from most Yilgarn calcretes sampled and are

considered to have evolved from a marine ancestor (Karanovic and Cooper 2012). Molecular investigation

of Schizopera species from the Yeelirrie calcrete system revealed that the genus was diverse with 12

species present (Bennelongia 2015, Karanovic and Cooper 2012, Subterranean Ecology 2011). Four of

these species possessed relatively widespread distributions within the Yeelirrie paleochannel system

(Schizopera akation, S. kronosi, S. leptafurca and S. uranusi) while three were found only from within the

central proposed impact area only. The remaining five species have only been recorded to date from within

the hypersaline groundwater environment of the Yeelirrie Lake playa system (Bennelongia 2015).

From the Lake Way associated calcrete systems, six Schizopera species were recorded (MWH 2015,

Outback Ecology 2012c). Three of these species were found to be more widespread within the Lake Way

system recorded from the main calcrete bodies present. Three species were found to be less widespread

and were recorded from the Hinkler Well calcrete system bordering the Lake Way playa. Schizopera

species were commonly recorded from highly saline groundwater environments but were also found to

inhabit fresh to hyposaline conditions.

At Lake Maitland four Schizopera species were recorded with all species, except Schizopera TK1, found to

be distributed within the main calcrete unit of the Barwidgee calcrete system from fresh groundwater

environments (Outback Ecology 2012a) (Figure D-5). All records of Schizopera TK1 were from hypersaline

groundwater conditions present near the Lake Maitland playa.


Schizopera sp. TK1 has been collected sympatrically with seven species, Ameiropsyllus sp. TK1,

Halicyclops sp. TK1, Halicyclops sp. TK2, Haloniscus sp. OES1, Naididae sp. OES2, Nitokra lacustris

pacifica, and Nitokra sp. TK3. The distributions of these seven species extended beyond the Mining

operations resource area further to the west up the Barwidgee calcrete body and all are known to occur in

less saline groundwater and within more substantial calcrete habitats. The broader distributions and habitat

preferences of these sympatric species indicate that contiguous habitable saturated geologies do extend

beyond the Mining operations resource area from along the margins of the northern lake playa system from

where Schizopera sp. TK1 was recorded.

Likely distribution range

It is considered unlikely that the distribution of Chiltoniidae sp. SAM4 is confined to the Lake Maitland

deposit area and associated modelled groundwater drawdown contours when taking into account the

physical and biological evidence presented above that demonstrates the presence of suitable and

connected habitat beyond the proposed Lake Maitland pit areas; the high likelihood that Chiltoniidae sp.

SAM4 does possess a relatively widespread distribution as exhibited by other chiltoniid species

recorded from other Yilgarn calcretes, including the Barwidgee calcrete system; and is able to tolerate

varying groundwater salinities as also exhibited by other chiltoniid species recorded from other Yilgarn

calcretes including the Barwidgee calcrete system.

A wider distribution range beyond the Lake Maitland mining operations resource area was not

demonstrated for Schizopera sp. TK1. However, it is considered likely that the distribution range of

Schizopera sp. TK1 is of wider extent within the Barwidgee calcrete ─ Lake Maitland playa aquifer system

and not confined to the mining operations resource area when taking into consideration the wider expanse

of more prospective habitat outside of the deposit area (either westwards up the Barwidgee calcrete or

southwards down the playa system), the wider distribution patterns and habitat preferences of other

Schizopera species, as well as other sympatric stygofauna.


3 Reinjection at Lake Maitland — Provide succinct assessment of potential impacts to troglofauna posed by the proposed groundwater reinjection scheme in and around the Lake Maitland playa to manage water from mine pit dewatering that may be surplus to reuse in the operational water supply at various stages of the Project.

For the Lake Maitland project area, Toro are proposing a groundwater reinjection scheme in the southern

part of the project area on Lake Maitland playa to manage water from mine pit dewatering that may be

surplus to reuse in the operational water supply at various stages of the project (Figure E-1). This process

will involve the reinjection of hypersaline water taken from the mined ore body panels into the Lake Maitland

playa aquifer system south of the proposed mining area that is of comparable salinity levels to minimise any

potential impacts to stygofauna species. The previous Lake Maitland troglofauna assessments completed

for Mega Uranium in 2012 had addressed the main direct impacts of mining excavation and associated

groundwater drawdown (Outback Ecology 2012b). However, the potential impacts of groundwater

reinjection on troglofauna at Lake Maitland were not assessed.

The reinjection of hypersaline water into the Lake Way playa south of the proposed mining area has the

potential to cause mounding of the groundwater. The proposed maximum level of mounding would be no

more than +1 m above the natural standing water level (aSWL). The mounding associated with reinjection

has the potential to reduce the extent of non-saturated subterranean habitats and therefore, could

potentially impact troglofauna that might occur in the proposed re-injection area (Figure E-1).

The habitat present in the re-injection area predominantly consists of salt lake playa or fringing playa

environment (Figure B-4: Section 1 and 2). The unsaturated geology present is predominantly

composed of fine grained clays or sand that would not be considered prospective troglofauna habitat as

there is likely not to be sufficient interstitial pore space present to enable colonisation. However, in the

more elevated areas extending into the lake playa there exists unsaturated coarse sediments consisting

of semi-consolidated carbonate/silica that could provide prospective habitat for troglofauna (Figure B-4: Section 1).

Troglofauna sampling in this area did record one species of troglofauna, a widespread isopod species,

Trichorina sp. OES6 (Figure E-2) (Outback Ecology 2012b). Trichorina sp. OES6 was recorded from

two bores, LMAC1209 and LMAC1227, within the re-injection area as well as from around the playa

system and across the Barwidgee calcrete (Figure E-2). The bore lithology logged for LMAC1209 from

an air core sample indicated that there was up to 2.5 to 3 m bGL of unsaturated semi-consolidated

carbonate/silica (originally referred to as clayey sand+calcrete and silcrete in Outback Ecology 2012b,

Appendix E) overlying clays above the SWL that ranged from 3.84 to 3.9 m bGL. For LMAC1227, the

logged air core sample indicated clay (originally referred to as clayey sand in Outback Ecology 2012b,

Appendix E) for 5 m bGL above the SWL at 5.35 m bGL. The only other bore to be sampled from this


area was LMAC1224 from which no troglofauna species were recorded. The air core sample indicated

lithology at LMAC1224 was similar to LMAC1227 with only unsaturated clay sediments present above

the SWL at 3.9 m bGL.

The troglofauna sampling and habitat assessment that has been conducted from around the re-injection

area indicated that the area is not highly prospective for troglofauna. The only species recorded from

this area, Trichorina sp. OES6, possess a relatively wide distribution that extends well beyond the

proposed reinjection zone as well as other proposed impact areas (Figure E-2). The limited habitat that

is present in the re-injection area does extend above the SWL for 3.8 to 5.35 m aSWL. Therefore, a

mounding of +1 m aSWL will result in the majority of the habitat present remaining unsaturated and

habitable for troglofauna that may occur in that area. For this reason the proposed groundwater

reinjection scheme in the southern part of the project area on the Lake Maitland playa is not considered

to pose a conservation issue for any species of troglofauna recorded from the Barwidgee calcrete

assemblage.


4 References

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Ground Waters. Academic Press, San Diego, pp 337-361 Boulton, A. J., Findlay, S., Marmonier, P., Stanley, E. H. and Valett, H. M. (1998) The functional

significance of the hyporheic zone in streams and rivers. Annual Review of Ecology and Systematics 29: 59-81.

Bradford, T., Adams, M., Guzik, M. T., Humphreys, W. F., Austin, A. D. and Cooper, S. J. B. (2013) Patterns of population genetic variation in sympatric chiltoniid amphipods within a calcrete aquifer reveal a dynamic subterranean environment. Heredity: 1-9.

Bradford, T., Adams, M., Humphreys, W. F., Austin, A. D. and Cooper, S. J. B. (2010) DNA barcoding of stygofauna uncovers cryptic amphipod diversity in a calcrete aquifer in Western Australia’s arid zone. Molecular Ecology Resources 10: 41–50.

Cooper, S. J. B., Bradbury, J. H., Saint, K. M., Leys, R., Austin, A. D. and Humphreys, W. F. (2007) Subterranean archipelago in the Australian arid zone: mitochondrial DNA phylogeography of amphipods from central Western Australia. Molecular Ecology 16: 1533-1544.

Cooper, S. J. B., Hinze, S., Leys, R., Watts, C. H. S. and Humphreys, W. F. (2002) Islands under the desert: molecular systematics and evolutionary origins of stygobitic water beetles (Coleoptera: Dytiscidae) from central Western Australia. Invertebrate Systematics 16: 589-598.

Cooper, S. J. B., Saint, K. M., Taiti, S., Austin, A. D. and Humphreys, W. F. (2008) Subterranean archipelago: mitochondrial DNA phylogeography of stygobitic isopods (Oniscidea: Haloniscus) from the Yilgarn region of Western Australia. Invertebrate Systematics 22: 195-203.

Dundon, P. J. (1997) Hinkler Well, Wiluna Sheet SG51-9. Report to Analex Pty Ltd, . Available online at. Environmental Protection Authority. (2013) Environmental Assessment Guideline (EAG) 12 for

consideration of subterranean fauna in environmental impact assessment in Western Australia. Finston, T. and Berry, O. (2011) Re. Report on the molecular systematics of the Chiltoniidae Report

prepared for Subterranean Ecology Golder Associates. (2011) Lake Maitland Uranium Project. Groundwater Studies. Draft. Internal report for

Mega Lake Maitland Pty Ltd, Perth, Western Australia. Guzik, M. T., Abrams, K. M., Cooper, S. J. B., Humphreys, W. F., Cho, J.-L. and Austin, A. D. (2008)

Phylogeography of the ancient Parabathynellidae (Crustacea:Bathynellacea) from the Yilgarn region of Western Australia Invertebrate Systematics 22: 205-216.

Guzik, M. T., Austin, A. D., Cooper, S. J. B., Harvey, M. S., Humphreys, W. F., Bradford, T., Eberhard, S. M., King, R. A., Leys, R., Muirhead, K. A. and Tomlinson, M. (2010) Is the Australian subterranean fauna uniquely diverse? Invertebrate Systematics 24: 407-418.

Guzik, M. T., Cooper, S. J. B., Humphreys, W. F., Ong, S., Kawakami, T. and Austin, A. D. (2011) Evidence for population fragmentation within a subterranean aquatic habitat in the Western Australian desert. Heredity: 1-16.

Karanovic, T. and Cooper, S. J. B. (2011) Molecular and morphological evidence for short range endemism in the Kinnecaris solitaria complex (Copepoda: Parastenocarididae), with descriptions of seven new species. Zootaxa 3026: 1-64.

Karanovic, T. and Cooper, S. J. B. (2012) Explosive radiation of the genus Schizopera on a small subterranean island in Western Australia (Copepoda: Harpacticoida): unravelling the cases of cryptic speciation, size differentiation and multiple invasions. Invertebrate Systematics 26: 115-192.

Leijs, R. (2011) Molecular biodiversity assessment of the stygofauna from the Lake Maitland and the Wiluna area South Australian Museum. Internal report prepared for Outback Ecology, Adelaide.

Leijs, R., Watts, C. H. S., Cooper, S. J. B. and Humphreys, W. F. (2003) Evolution of subterranean diving beetles (Coleoptera: Dytiscidae: Hydroporini, Bidessini) in the arid zone of Australia. Evolution 57(12): 2819-2834.

MWH. (2015) Wiluna Uranium Project: Millipede Targeted Subterranean Fauna Assessment Report prepared for Toro Energy Ltd.

MWH. (2016a) Wiluna Extension Uranium Project: MWH responses to DotE, DPAW & CCWA PER comments re: subterranean fauna (20/04/2016).

MWH. (2016b) Wiluna Extension Uranium Project: MWH responses to OEPA PER comments re: subterranean fauna (26/04/2016).


Outback Ecology. (2011) Wiluna Uranium Project Subterranean Fauna Assessment, March 2011. Prepared for Toro Energy Ltd, Perth, Western Australia.

Outback Ecology. (2012a) Lake Maitland Uranium Project Level 2 Stygofauna Assessment Prepared for Mega Lake Maitland Pty Ltd, Perth, Western Australia.

Outback Ecology. (2012b) Lake Maitland Uranium Project Level 2 Troglofauna Assessment Prepared for Mega Lake Maitland Pty Ltd, Perth, Western Australia.

Outback Ecology. (2012c) Wiluna Uranium Project Stygofauna Assessment Prepared for Toro Energy Ltd, Perth, Western Australia.

RPS Aquaterra. (2010a) Centipede Groundwater Impact Assessment Report prepared for Toro Energy Limited, 1134C/169a, Western Australia.

RPS Aquaterra. (2010b) Lake Maitland Costean Programme - Dewatering Investigations Internal report prepared for Mega Lake Maitland Pty Ltd, Perth, Western Australia.

Subterranean Ecology. (2011) BHP Billiton Yeelirrie Development Company Pty Ltd. Yeerlirrie Uranium Project. Subterraean Fauna Survey.

Toro Energy Limited. (2012) Wiluna Uranium Project: Environmental Review and Management Program (ERMP) EPA assessment No. 1819: Response to submissions.

Toro Energy Limited. (2015) Extension to the Wiluna Uranium Project. Assessment No: 2002 (CMS14025) Public Environmental Review. November 2015.

Toro Energy Limited. (2016) UPDATE ON THE RE-INTERPRETATION OF WILUNA GEOLOGY – IMMEDIATE IMPLICATIONS. Memorandum from Toro Energy Geology Team (21/06/2016).

Watts, C. H. S. and Humphreys, W. F. (2006) Twenty-six new Dytiscidae (Coleoptera) of the genera Limbodessus Guignot and Nirripirti Watts and Humphreys from underground waters in Australia. Transactions of the Royal Society of South Australia 130(1): 123 - 185.

Watts, C. H. S. and Humphreys, W. F. (2009) Fourteen new Dytiscidae (Coleoptera) of the genera Limbodessus Guimot, Paroster Sharp, and Exocelina Broun from underground waters in Australia. Transactions of the Royal Society of South Australia 133(1): 62-107.


Appendix A Habitat associated with the Millipede / Centipede Mining Area and the Hinkler Well Calcrete System


Figure A-1: Cross section through the Centipede/Millipede deposit showing the lithology through the Centipede ore zone and the Millipede ore zone but including an oblique of the surface to show geomorphological relationships. (source: Toro Energy Limited (2016)).


Figure A-2: Schematic depiction of geology present across Millipede based on new geology model (provided by Toro Energy Limited).


Figure A-3: Old geology model schematic depiction of geology present in Millipede and Centipede project areas: A) Locality map of schematic cross sections; B) Schematic cross sections 1 to 3 (source: modified from Toro Energy (2012).

Figure A-3: Core photos (0 to 9 mbGL ) of bores that are in close proximity to the recorded locations of Chiltoniidae sp. SAM6 (refer Figure C-1). Near to Bore GT12 — A) Bore WS153; and B) Bore WS152; Closest available to bore GT1-A — C) Bore WS169; and D) Bore WS170.


Figure A-3: Extent modelled ‘calcrete’ habitat associated with the Hinkler Well calcrete system: A) Plan view; B) Lateral view, looking north.

Table A-1: Summary of air core bore lithologies from Millipede / Centipede Project area, SWL, and stygofauna recorded (Outback Ecology 2012c).

From ToNLW10 0 7.5 Calcrete 4.8 (Jul. 2007) 2.7 Limbodessus hink leri

7.5 10 Gravel Halicyclops eberhardiNLW11 0 7.5 Calcrete 4.8 (Jul. 2007) 2.7 Schizopera uramurdahi

7.5 9.5 SandNLW19 0 3.5 Sand 3 (Jul. 2007) 0 Enchytraeidae

3.5 7 Weathered basement 3.4 (Nov 2011)Feb. 2010May 2010

NLW20 0 10 Sand 3 (Jul. 2007) 0 Parapseudoleptomesochra sp. TK13.2 (Nov. 2009) Schizopera austindownsi

Feb. 2010May 2010 3.7

NLW21 0 4.5 Calcrete 3.7 (Jul. 2007) 0.8 Chiltoniidae sp. ?SAM34.5 10 Sand Feb. 2010 Limbodessus hink leri

Schizopera uramurdahi Enchytraeidae

May 2010 Halicyclops eberhardiNLW22 0 4.5 Calcrete 3.5 (Jul. 2007) 1 Limbodessus hink leri

4.5 10 Sand 3.88 (Nov. 2009) Halicyclops eberhardi4.4 (Aug. 2010) Australocamptus similis

Feb. 2010 Schizopera uramurdahi May 2010

NLW23 0 4.5 Calcrete 3.6 (Jul. 2007) 0.9 Limbodessus hink leri4.5 10 Sand 3.8 (Nov. 2009) Halicyclops eberhardi

Feb. 2010 Australocamptus similisMay 2010 Schizopera uramurdahi

NLW4 0 0.5 NR 2.1 (Jul. 2007) 0 Ameiropsyllus sp. TK10.5 10 Clay

NLW5 0 0.5 NR 1.6 (Jul. 2007) 4.60.5 5 Calcrete5 10 Sand

NLW7 0 0.5 Sand 2.8 (Jul. 2007) 6.8 Chiltoniidae sp. ?SAM30.5 8 Calcrete Bathynellidae8 9 Sand

NLW9 0 0.5 Sand 4.7 (Jul. 2007) 4.7 Limbodessus0.5 8 Calcrete Limbodessus hink leri

Schizopera uramurdahi 8 10 Gravel Halicyclops eberhardi

Stygofauna taxa collectedBore codeGeological sample

intervals (m bgl) Bore lithologies SWL (m bgl) & sample date

Depth saturated calcrete present (m)

Table A-1 (cont.): Summary of air core bore lithologies from Millipede / Centipede Project area, SWL, and stygofauna recorded.

From ToNVCP2 0 0.5 NR 1.3 (Nov. 2009) 3.2 Chiltoniidae sp. ?SAM3

0.5 1 Sand Feb. 2010 Brevisomabathynella sp. SAM21 4.5 Calcrete May 2010 Halicyclops eberhardi

4.5 5 Sand Nitokra sp. TK15 8.5 Clay Nitokra sp. TK2

8.5 9 Sand9 9.5 Clay

9.5 10 SandNVCP3 0 0.5 NR 1.3 (Nov. 2009) 0

0.5 10 Clay Feb. 2010May 2010

NVCP4 0 2 Gravel 2.2 (Nov. 2009) 3.2 Brevisomabathynella sp. SAM22 5 Calcrete May 2010 Nitokra sp. TK25 12 Clay

NVCT0010 0 2.5 Calcrete 1.6 (Jul. 2007) 0.9 Schizopera austindownsi2.5 9 Weathered basement

NVCT0033 0 0.5 NR 1.2 (Jul. 2007) 6.50.5 1 Calcrete1 1.5 Sand

1.5 7 Calcrete7 10 Sand

NVCT0058 0 3 Sand 1.2 (Jul. 2007) 1.5 Schizopera sp. TK43 5 Clay5 6 Calcrete6 7 Sand7 7.5 Calcrete

7.5 9 Sand9 10 Clay

NVCT0077 0 3.5 Sand 5.6 (Jul 2007) 1.93.5 7.5 Calcrete7.5 14 Sand

NVCT0170 0 1 NR 4.8 (Jul. 2007) 5.8 Halicyclops eberhardi1 9 Calcrete9 10 Weathered basement

Bore codeGeological sample


Depth saturated calcrete present (m) Stygofauna taxa collected


From ToNVCT0174 0 9.5 Calcrete 3.97 (Nov. 2011) 5.53 Chiltoniidae sp. ?SAM3

9.5 10 Sand 4.37 (Nov 2009) Atopobathynella wattsiSchizopera austindownsiNitokra sp. TK1Schizopera uramurdahi

Mar. 2010 DytiscidaeNVCT0215 0 7 Calcrete 4.6 (Jul. 2007) 3.6

7 10 SandNVCT0225 0 1 NR 2.4 (Jul. 2007) 2.9 Chiltoniidae sp. ?SAM3

1 1.5 Sand Limbodessus ?hink leri1.5 3 Calcrete Limbodessus hink leri3 5 Sand Halicyclops eberhardi5 6.5 Calcrete

6.5 9.5 Clay9.5 10 Sand

NVCT0424 0 0.5 NR 0.8 (Jul. 2007) 6.20.5 7 Calcrete7 10 Sand

NVCT0437 0 0.5 NR 1.6 (Jul. 2007) 5.4 Halicyclops eberhardi0.5 5.5 Calcrete5.5 6 Clay6 7 Calcrete7 9 Sand9 9.5 Gravel

9.5 10 CalcreteNVCT0473 0 6.5 Calcrete 1.7 (Jul. 2007) 4.8 Atopobathynella wattsi

6.5 7.5 Sand 1.85 (Nov. 2009) Halicyclops eberhardiSchizopera austindownsi

7.5 9 Clay Feb. 2010 Nitokra sp. TK19 10 Sand May 2010 Nitokra sp. TK2

NVCT0483 0 0.5 NR 1.6 (Jul. 2007) 8.4 Limbodessus0.5 10 Calcrete

NVCT0495 0 4.5 Calcrete 1 (Jul. 2007) 3.5 Ameiropsyllus sp. TK14.5 8.5 Clay8.5 10 Sand

NVCT0588 0 0.5 NR 1.36 (Jul. 2007) 2.36 Nitokra sp. TK10.5 1 Sand Schizopera austindownsi1 3 Calcrete3 10 Clay





From ToNVCT0612 0 0.5 NR 1 (Jul. 2007) 2.5 Atopobathynella ?wattsi

0.5 3.5 Calcrete Limbodessus3.5 7.5 Clay Halicyclops eberhardi

NaididaeCandonopsis (Abcandonopsis) linnaei

7.5 10 Sand Schizopera austindownsiNVCTA 0 1 Sand 2.9 (Nov. 2009) 0

1 12 Weathered basement Feb. 2010May 2010

OBS1 0 1 Clay 1.9 (Nov 2009) 11 Halicyclops eberhardi1 2 Gravel Schizopera sp. TK72 6 Calcrete6 7 Gravel7 15 Clay

15 20 Calcrete20 21 Gravel21 23 Calcrete23 26 Feericrete26 27 Gravel27 33 Clay

OBS2 0 2 Gravel 1.34 (Nov. 2009) 42 6 Calcrete6 20 Clay

20 26 Gravel26 30 Clay

OBS4 0 4 Calcrete 1.8 (Nov 2009) 2.24 9 Clay9 10 Sand

OBS6 0 0.8 Clay 1.9 (Nov. 2009) 0 Chiltoniidae sp. ?SAM30.8 1.4 Sand Limbodessus hink leri1.4 5.7 Clay Dussartcyclops uniarticulatus5.7 7.2 Gravel Halicyclops eberhardi7.2 7.7 Clay Schizopera sp. TK77.7 8.3 Gravel Schizopera uramurdahi 8.3 8.5 Clay





Appendix B Habitat associated with Lake Maitland Mining Area (including proposed reinjection zone) and Barwidgee Calcrete System


Figure B-1: Comparison of historical v 2016 re-interpretation of the geology at Lake Maitland using an E-W section through the northern end of the deposit. The core photographs of WS217 have been included to show the validity of the 2016 re-interpretation of clay rather than ‘calcrete’ through the ore zone (source: Toro Energy Limited (2016)).

Figure B-2: 3D geological model of the first phase re-interpretation of the geology of the Lake Maitland Uranium Deposit (source: Toro Energy Limited (2016)).


Figure B-3: Schematic depiction of geology present at Lake Maitland based on new geology model (provided by Toro Energy Limited).

Figure B-4: Schematic depiction of geology present at Lake Maitland based on new geology model (provided by Toro Energy Limited).


Figure B-5: Core photos of bores that are in close proximity to recorded locations of Chiltoniidae sp. SAM4 (refer Figure D-1) and Schizopera sp. TK1 (refer Figure D-2). Near to Bore EH01 — A) Bore LMDD0253; near to bore LMAC0352 — B) Bore LMDD0084; Closest available to bore LMAC0448 — C) Bore LMDD0078; and D) Bore LMDD0082.


Figure B-6: Aquifer types and hydrogeological information of the Carey paleochannel within the Barwidgee calcrete / Lake Maitland system, (Figure sourced from Golder Associates (2011) page 50).

Table B-1: Air core logged bore lithologies, Standing Water Levels, Salinity, Dissolved Oxygen and Stygofauna recorded (Outback Ecology 2012a).

From To (m bgl) ppt mS/cm (ppm)Ameiropsyllus sp. TK1 LMAC0448 1 2 Calcrete 1.07 - 1.61 1.43 70 - 97 122.5 - 141.4 0.01 - 16.04

2 2.5 Calcrete+Clay2.5 9 Clay+Grit

Atopobathynella sp. LMAC0423 1 3.5 Calcrete+Clay 1.5 - 2.32 2.5 44 61.9 - 72.2 23.33.5 4 Clay+Calcrete4 7 Clay+Grit

Halicyclops eberhardi LMAC0012 1.5 4.5 Calcrete 1.51 - 1.8 4.99 56.1 - 72.5 80 - 123.2 2.57 - 15.414.5 6.5 Clay+Calcrete6.5 9 Clay

LMSC-021 1.5 2 Calcareous Clay 1.64 0 71.8 94.6 1.022 3 Clay3 4 Sandy Clay

9.5 12 Clayey SandHaloniscus sp. OES1 LMAC0012 1.5 4.5 Calcrete 1.51 - 1.8 4.99 56.1 - 72.5 80 - 123.2 2.57 - 15.41

4.5 6.5 Clay+Calcrete6.5 9 Clay

LMAC0352 1 1.5 Clay+Ferricete 1.16 - 1.38 0 70 - 102.6 128.1 - 129.6 2.86 - 16.541.5 7 Clay

LMAC0448 1 2 Calcrete 1.07 - 1.61 1.43 70 - 97 122.5 - 141.4 0.01 - 16.042 2.5 Calcrete+Clay

2.5 9 Clay+GritLMAC0545 1.5 2 Grit 1.5 1 54.8 75.5 4.98

2 2.5 Calcrete+Grit3 3.5 Grit+Clay

Naididae sp. OES2 LMAC0334 1 7 Clay 1 - 1.05 0 70 - 113 139.4 - 150 1.97 - 19.76LMAC0448 1 2 Calcrete 1.07 - 1.61 1.43 70 - 97 122.5 - 141.4 0.01 - 16.04

2 2.5 Calcrete+Clay2.5 9 Clay+Grit

Schizopera sp. TK1 LMAC0352 1 1.5 Clay+Ferricete 1.16 - 1.38 0 70 - 102.6 128.1 - 129.6 2.86 - 16.541.5 7 Clay

LMAC0448 1 2 Calcrete 1.07 - 1.61 1.43 70 - 97 122.5 - 141.4 0.01 - 16.042 2.5 Calcrete+Clay

2.5 9 Clay+Grit

SalinityStygofauna taxa collected Bore Code

Depth (m bgl) Saturated habitat present

Depth saturated calcrete present

(m)

SWL DO

Table B-1 (cont.): Air core logged bore lithologies, SWL, Salinity, Dissolved Oxygen and Stygofauna recorded (Outback Ecology 2012a).

From To (m bgl) ppt mS/cm (ppm)No stygofauna recorded LMAC0008 1.5 4 Calcrete 1.8 4.2 33.7 51.2 19.85

4 5 Calcrete+Clay5 6 Clay+Calcrete6 9 Clay

LMAC0009 1.5 2 Calcrete+Clay 1.8 - 2.03 4.7 45.2 - 58.7 66.5 - 79.6 4.84 - 17.252 3.5 Calcrete

3.5 6.5 Clay+Calcrete6.5 9 Clay

LMAC0010 1.5 2 Clay+Calcrete 1.5 5.5 53.2 76.4 15.852 4 Calcrete4 7 Clay+Calcrete7 9 Clay

LMAC0011 1.5 3.5 Calcrete 1.9 - 2.18 4.6 40.8 - 56.6 60.6 - 77 4.73 - 16.873.5 4 Calcrete+Clay4 6.5 Clay+Calcrete

6.5 9 ClayLMAC0147 2 2.5 Clay 2 0 80.3 104.4 4.24

2.5 3 Clay+Ferricrete3 9 Clay

LMAC0160 3.5 4 Calcrete+Ferricrete 3.5 -3.55 1.5 29.5 - 38.6 45.3 - 54.6 3.88 - 15.494 4.5 Calcrete

4.5 5 Clay+Calcrete5 9 Clay

LMAC0168 2.5 3 Calcrete 2.5 1 43.2 60.3 3.553 3.5 Calcrete+Clay

3.5 9 ClayLMAC0179 1 1.5 Clay 1.18 - 1.45 3.32 70 - 81.8 103.6 - 106.2 4.02 - 20

1.5 2 Ferricrete+Clay2 2.5 Ferricrete

2.5 3 Ferricrete+Calcrete3 3.5 Calcrete+Ferricrete

3.5 4 Calcrete4 4.5 Clay+Calcrete

4.5 9 ClayLMAC0212 0.5 9 Clay 0.95 - 1.05 0 70 - 146.6 169 - 176.4 3.61 - 17.9LMAC0266 0.5 7 Clay 08-.8 - 1 0 70 - 118.1 143 - 157.2 2.37 - 18.43

Stygofauna taxa collected Bore Code Depth (m bgl) Saturated habitat present

SWL DODepth saturated calcrete present

(m)

Salinity

Table B-1 (cont.): Air core logged bore lithologies, SWL, Salinity, Dissolved Oxygen and Stygofauna recorded (Outback Ecology 2012a).

DODO (ppm)

From To (m bgl) ppt mS/cm (ppm)No stygofauna recorded LMAC0291 3.5 4 Clay+Calcrete 3.5 2.5 48.1 66.6 3.56

4 4.5 Calcrete+Clay4.5 6 Calcrete6 7 Clay

LMAC0312 1 7 Clay 1.36 - 2.62 0 70 - 117.6 141.9 - 150.2 1.62 - 15.82LMAC0399 2.5 4 Calcrete 2.5 2.5 43.8 61.2 3.09

4 4.5 Calcrete+Clay4.5 5 Calcrete5 7 Grit

LMAC0401 1.5 3.5 Calcrete 1.5 2 46.8 65 2.453.5 7 Grit+Clay

LMAC0406 2.5 5.5 Calcrete 2.5 3 32.4 46.3 4.025.5 7 Grit

LMAC0505 4.5 5.5 Calcrete 4.5 5.5 30.2 43.5 1.645.5 8 Clay+Calcrete8 9 Clay

LMAC0527 1.5 4 Calcrete 1.7 3.7 70 125.7 15.14 9 Clay+Grit

LMAC0541 1.5 3.5 Calcrete 1.57 2.43 70 105.2 15.883.5 4 Clay+Calcrete4 9 Grit

Stygofauna taxa collected Bore Code Depth (m bgl) Saturated habitat present

SWL Depth saturated calcrete present

(m)

Salinity


Appendix C Recorded distributions of the stygofauna species associated with the Hinkler Well Calcrete System. Data from Outback Ecology (2012b) and MWH (2015)


Figure C-1: Millipede/Centipede (Hinkler Well calcrete) Project area stygofauna sample sites indicating recorded presence or absence.

Figure C-2: Distribution of Amphipoda species recorded from 2007 to 2015 within the Hinkler Well calcrete.

Figure C-3: Distribution of Bathynellacea species recorded from 2007 to 2015 within the Hinkler Well calcrete.

Figure C-4: Distribution of diving beetle species recorded from 2007 to 2015 within the Hinkler Well calcrete.

Figure C-5: Distribution of Cyclopoida copepod species recorded from 2007 to 2015 within the Hinkler Well calcrete.

Figure C-6: Distribution of Harpacticoida copepod species recorded from 2007 to 2015 within the Hinkler Well calcrete.

Figure C-7: Distribution of Oligochaeta recorded from 2007 to 2015 within the Hinkler Well calcrete.

Figure C-8: Distribution of Ostracoda species recorded from 2007 to 2015 within the Hinkler Well calcrete


Appendix D Recorded distributions of the stygofauna species associated with the Barwidgee Calcrete System.

Data from Outback Ecology (2012a)


Figure D-1: Lake Maitland (Barwidgee calcrete) Project area overview of stygofauna sample sites indicating recorded presence or

absence.

Figure D-2: Lake Maitland (Barwidgee calcrete) mining operations stygofauna sample sites indicating recorded presence or absence.

Figure D-3: Distribution of Amphipoda species recorded within the Barwidgee calcrete system.

Figure D-4: Distribution of Halicyclops (Copepoda) species recorded within Barwidgee calcrete system.

Figure D-5: Distribution of Schizopera (Copepoda) species recorded within Barwidgee calcrete system

Figure D-6: Distributions of Ameiropsyllus, Australocamptus, Kinnecaris, Microcyclops, Nitokra (Copepoda) species recorded within Barwidgee calcrete system.

Figure D-7: Distributions of Bathynellacea and Dytiscidae species recorded within Barwidgee calcrete system

Figure D-8: Distributions of Oligochaeta species recorded within Barwidgee calcrete system.

Figure D-9: Distributions of Isopoda and Ostracoda species recorded within Barwidgee calcrete system


Appendix E Recorded diversity, distributions and habitats of the troglofauna assemblage associated with the Barwidgee Calcrete system and in relation to the proposed reinjection area.

Data from Outback Ecology (2012a)


Table E-1: Troglofauna diversity and distributions recorded from the Barwidgee calcrete system. Identified species and morphospecies shaded in: orange have not been found to date from outside of the Lake Maitland proposed mining area: yellow have not been found to date from outside of the proposed groundwater drawdown contour > 0.5 m bSWL.

Groundwater drawdown Resource

Scolopendridae sp. OES1 1 1

Meenoplidae* 3 3

Haloniscus sp. OES12 * 41 37 4

Haloniscus sp. OES14 * 22 22

Trichorhina sp. OES6 * 95 6 72 17

Pauropodina 2 1 1

Tyrannochthonius sp. OES4 * 4 3 1

Tyrannochthonius sp. OES5 * 1 1

Tyrannochthonius sp. OES6* 1 1

Tyrannochthonius indet. 1 1

Taxon Total abundance Non-impact

Impact

Mining operations areaNorthern

Borefield

Pseudoscorpionida

Chthoniidae

Chilopoda

Hemiptera

Isopoda

Scyphacidae

Platyarthiridae

Pauropoda


Figure E-1: Lake Maitland mining operations troglofauna sample locations indicating recorded presence or absence.

Figure E-2: Distribution of Isopoda species recorded from within the Barwidgee calcrete system.

Figure E-3: Distribution of Pseudoscorpionida species recorded from within the Barwidgee calcrete system.

Figure E-4: Distribution of Chilopoda, Hemiptera and Pauropoda species recorded from within the Barwidgee calcrete system.

June 27, 2016 Toro Energy Ltd Level 3, 33 Richardson Street 6005 … · 1 Millipede / Centipede...

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