6A Surface Water Assessment - Supporting Information · 6A Surface Water Assessment - Supporting...

Simandou SEIA Volume I Mine Annex 6A

6A-1

6A Surface Water Assessment - Supporting Information This annex to Chapter 6: Water Environment presents surface water baseline and modelling data that have been used in the undertaking of the impact assessment of the Simandou Mine that are not otherwise presented in the chapter. This annex presents information and data in the following sections: Section 6A.1 – Surface Water Flows; Section 6A.2 – Surface Water Quality; Section 6A.3 – Surface Water Users; and Section 6A.4 – Groundwater Modelling Results. 6A.1 Surface Water Flows The main rivers in Upper and Forest Guinea that lie downstream of the mining area are shown in Figure 6A.1 and characterised in Table 6A.1 and Figure 6A.2. The locations of the various gauging stations from which these data were compiled are shown in Figure 6A.1. As shown in Figure 6A.2, the annual hydrographs in all of the major rivers follow a similar pattern to those in Table 6A.1. Flows gradually increase following the onset of the rainy season in April / May, reach their peak around September and then tail off again to groundwater-fed baseflow conditions in January / February. The peak flows may arrive sooner in some of the smaller catchments, and the duration of the flood flow hydrograph will be longer in some of the larger catchments and also those in the south of the country where the rainfall season is more extended. Table 6A.1 Summary of Average Monthly Flows (m3/s) for Rivers Downstream of the Mine Site

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg

Niger River Basin

Niger River at Tiguibery (May 1952-Dec 1979)

Monthly mean 267 139 82.1 63.5 91.7 331 1 015 2 349 3 782 3 216 1 465 569 1 114

Daily max. 644 342 254 218 487 1 840 3 440 5 230 6 700 7 170 5 630 2 080 7 170

Daily min. 65.4 36.7 15.8 15.8 20.2 36.7 137 602 1 600 949 346 150 15.8

No. months record

24 23 23 23 25 25 26 26 26 26 26 26

Milo River at Kankan (Jan 1952-Feb 2006)

Monthly mean 32.2 18.7 14.3 16.2 27.8 80.2 224 456 601 398 166 68.7 175

Daily max. 103.0 62.2 61.3 87.1 144.0 465.0 881.4 911.8 1022 1036 701.6 325.0 1 036

Daily min. 2.9 0.5 0.0 0.0 0.7 0.9 1.3 46.3 253.7 81.3 29.3 11.3 0

No. months record

47 47 46 46 46 45 45 44 45 45 45 45

Milo River at Kérouané (Aug 1970-Dec 1980)

Monthly mean 11.8 6.4 4.0 6.2 12.3 33.1 59.1 105 128 74.4 48.4 23.1 42.6

Daily max. 42.6 13.0 19.7 29.1 63.3 116 179 175 235 187 114 62.9 235

Daily min. 6.3 1.9 1.8 2.1 2.1 3.1 2.4 14.1 62.6 23.9 17.8 7.6 1.8

No. months record

3 4 5 5 6 5 6 8 8 7 7 6

Milo River at Konsankoro (Mar 1955-Dec 1980)

Monthly mean 7.8 6.2 6.8 9.2 11.8 27.4 45.8 67.9 83.9 49.9 22.9 13.0 29.4

Daily max. 24.8 21.9 40.6 58.7 128 308 341 340 385 322 177 58.7 385

Daily min. 4.2 1.3 0.9 1.0 1.6 2.0 1.6 8.8 8.2 1.6 1.6 2.8 0.9

No. months record

11 13 16 16 19 20 17 20 21 17 14 10


6A-2

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg

Dion River at Baranama (Jan 1971-Mar 2006)

Monthly mean 38.0 28.0 18.7 18.3 33.0 61.5 115.5 212.4 260.6 175.8 91.3 51.5 100.9

Daily max. 193 159 130 76.6 137 223 377 406 394.2 375 321 193 406

Daily min. 4.2 1.9 1.4 2.7 5.7 14.6 20.8 30.9 104 37.7 15.9 10.5 1.4

No. months record

19 19 19 19 19 23 24 26 26 25 24 21

Diani River Basin

Diani River at Bac (Mar 1975-Jul 2006)

Monthly mean 23.6 15.6 16.5 28.8 41.0 69.6 124 246 295 202 103 44.8 92.1

Daily max. 220 117 182 93.0 154 325 292 514 551 574 551 194 574

Daily min. 10.8 6.8 5.4 4.6 6.8 10.6 16.5 30.6 91.9 71.4 42.5 21.5 4.6

No. months record

28 27 28 29 29 29 28 28 28 28 27 27

Faranah

Kouroussa

Kankan

Kerouane

Baro

Kissidougou

Mandiana

Tinkisso

Baranama

KérouanéDialakoro

Tiguibery

Madina

Seredo

Bac

Sérékoroba

Diamaradou

Konsankoro

M

ilo

Niandan

Milo

Tinki s soTinkisso

Nig

e r

Nige r

Tinkiss

o

Niandan

Moa

Nia ndan

Mil o

S

ankarani

S ew

a

Milo

Nig

e

r

Nig er

Ba fing

Niger

San

kara

ni

Mo a

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Niger

St-Paul

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Client: Taille: Titre:Légende:

Figure 6A.1

Lignes régionales de partage des eaux et réseau hydrométrique national dans la zone de la mine / Regional Watersheds and National Hydrometric Network in the Mining Area

Station hydrographique / Hydrographic Station

Station de jaugeage et d'échantillonnage de la qualité de l'eau (GIRENS) / River Gauging and Water Quality Monitoring Station (GIRENS)

Station de jaugeage (ouverte) / River Gauging Station (Open)

Station de jaugeage (fermée) / River Gauging Station (Closed)

Cours d'eau principale / Primary Watercourse

Cours d'eau secondaire / Secondary Watercourse

Cours d'eau tertiaire / Tertiary Watercourse

Bassin versant / WatershedRégional / Regional

Diani

Dion

Loffa

Milo

Niger

Frontière entre états / National Boundary

Projection: WGS 1984 UTM Zone 29N

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Dessiné par: WB

Vérifié par: TS

Approuvé par: KR

Projet: 0131299

Echelle: Comme barre d'échelle


6A-4

Figure 6A.2 Hydrogrammes saisonnier pour les principales rivières de la zone de la mine / Seasonal Hydrographs for Main Rivers in Mining Area


6A-5

The flow regime at Simandou is controlled by the seasonal rainfall regime. Figure 6A.3 shows the flow records at Whisky 1 and Whisky 2 weirs, which have catchment areas of 0.5 km2 and 0.4 km2 respectively. Also shown are daily rainfall records from Canga East rain gauge. While the wet season rainfall mostly begins in March, stream flows remain low until early July while soil moisture deficits are replenished. Flow increases from early July. Figure 6A.3 Flow Hydrographs in Whisky 1 and Whisky 2 Catchments

The increase in flow is likely to be caused by discharge from soil and groundwater stores in the hill slopes of the adjacent cangas that have been filling since the rains began. Seasonal flow remains high as long as rainfall continues. As rainfall declines in September / October the stores drain and flow recedes. The flow recession continues through the dry season, fed from the subsurface system. The ‘spikes’ in the graph are flood events which occur in response to heavy rainfall. Observations suggest that during the early and late parts of the rainy season storm hydrographs rise and recede rapidly with no substantial recessions. Overland flow close to the channels is likely to be the main mechanism generating storm hydrographs. During the middle of the rainy season hydrographs exhibit more prolonged recessions, indicating water discharging from a storage that has by then been filled. Storm flow percentages for individual storms on Whisky 1 and Whisky 2 catchments range from 5.1% to 31.2%. This range may be typical of other small mountain catchments of up to 1 km2 in area. To date no specific work has been done on lag times between start of rain or time of peak rainfall intensity and peak flow. However, lag times are typically of the order of a few tens of minutes on mountain catchments like Whisky 1 and Whisky 2. The hydrological regime of mountain streams draining Ouéléba and Pic de Fon, exemplified by the Whisky 1 and Whisky 2 records, is perennial, dominated by groundwater discharge (baseflow), and with a flashy storm runoff regime superimposed. This basic regime is maintained at stations downstream, such as the Loffa River at Foma Village (catchment area 191 km2) (Figure 6A.4).


6A-6

Figure 6A.4 Rainfall and Flow in the Loffa River at Foma, Pic de Fon

Baseflow (sometimes called slow flow) is normally considered to originate from the discharge of groundwater and / or soil water. Storm flow (sometimes called quick flow) is usually considered to result from overland flow, either from saturated areas close to stream channels or from slopes as a result of the exceedance of soil infiltration capacities by heavy rainfall. Some storm flow may also originate from rapid subsurface flow in the soil zone. High stream flows resulting from storm rainfall consist of storm flow. Low flow in between flood events or between one wet season and the next can be considered to be baseflow. Baseflow has been estimated for Simandou streams by separating it from the total flow hydrograph, as shown for the Loffa in Figure 6A.5. The resulting baseflow hydrographs are shown in Figure 6A.6. Figure 6A.5 Baseflow Separation for the Loffa River at Foma

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nga East (m

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6A-7

Figure 6A.6 Seasonal Baseflow Hydrographs in Mine Catchments

In summary: the Western Spur River has the most constant baseflow regime of all rivers shown. This results from a

constant high discharge from groundwater storage in the Pic de Fon ore body and a buffering effect by the thick tropical forest reducing the stream flow response to rainfall in the wet season; and

other rivers which drain Pic de Fon or Ouéléba obtain varying degrees of support in the dry season from

the groundwater system within the ore bodies. The proportion of total flow made up of baseflow is a characteristic of a stream’s hydrological regime and is called the Base Flow Index (BFI). Table 6A.2 presents estimated values of BFI for the various catchments around the mine. Table 6A.2 Estimated Baseflow Index Values for Rivers in Simandou Area

River Baseflow Index Period of Record

Simandou Eastern Flank

Miya River at Nionsonmoridou 0.73 11 Aug 2007 to 29 Nov 2009

Loffa River at Canga Road 0.66 29 Nov 2007 to 17 Feb 2010

Boe River at Foma 0.61 31 Jan 2008 to 30 Dec 2009

Simandou Western Flank

Kinyeko River at Traoréla 0.81 24 Jan 2008 to 31 Jan 2010

Mala River at Traoréla 0.71 24 Jan 2008 to 30 Dec 2009

West Spur River at Mandou footpath 0.90 23 Feb 2008 to 10 Feb 2010

Whisky 2 weir 0.64 20 Nov 2005 to 1 Jan 2010

Pulowaye River at Banko 0.58 14 Feb 2008 to 30 Dec 2009

Wolou River at Banko 0.82 6 Aug 2008 to 9 Feb 2010

0.01

0.1

1

10

Aug‐07 Nov‐07 Feb‐08 May‐08 Aug‐08 Nov‐08 Feb‐09 May‐09 Aug‐09 Nov‐09 Feb‐10

Monthly Baseflow (m3/s )

Western Spur River

Kinyeko

Mala

Loffa at Canga Road

Miya River at Nionsonmoridou

Pulowaye at Banko

Wolou River at Banko

Dianiworo River at Tourela

Soumourou River at Gbonodou

Woron at Mandou

Woron River at Orono

Boe River at Foma


6A-8

River Baseflow Index Period of Record

Dianiworo River at Touréla 0.67 21 Feb 2008 to 30 Dec 2009

Woron River at Mandou 0.90 10 Feb 2008 to 29 Nov 2009

Woron River at Orono 0.71 16 Feb 2008 to 29 Nov 2009

Large (Regional) Rivers

Diani River at Bac Diani 0.79 1 Mar 1975 to 31 Dec 2006

Milo River at Konsankoro 0.53 1 Mar 1955 to 30 Aug 1990

Dion River at Baranama 0.88 1 Jan 1971 to 31 Mar 2006

In terms of the spatial pattern of flows across the mining area, Table 6A.3 presents an analysis of the spring survey carried out on the Pic de Fon and Ouéléba mountains in January and February 2008. Spring flow measurements are taken at the stream’s source, and are therefore more representative of baseflow than storm flow. The most significant observation is that between three and four times as much flow drains to the west as compared to the east on both mountains. In order to better understand the overall contribution to stream flows from the mountain aquifers, periodic flow measurements were performed along the length of the streams draining Pic de Fon and Ouéléba during the dry seasons of 2008 and 2009. Figure 6A.7 illustrates the flow contours derived from the 2008 dry season ‘flow accretion’ survey. Figures 6A.8 and 6A.9 summarise the results of the survey undertaken in January and February 2009, which also incorporated the wider regional stream network. Table 6A.3 Dry Season Flow in East and West Flank Springs, Jan-Feb 2008

Indicator

Pic de Fon Ouéléba

East West All East West All

Flow per spring (l/s)

0.16 0.77 0.40 0.13 0.25 0.21

Total flow (l/s)

16.5 54.3 70.6 4.4 16.5 20.9

No. springs

105 71 176 35 67 102

As shown, stream flow increases with distance downstream and the rate of increase appears to be relatively uniform to the east and west of the Ouéléba deposit. Conversely, there are significant differences in the rate of increase either side of the Pic de Fon deposit. On the west side there are specific points at which the flows increase very rapidly, notably on the Western Spur valley to the north-west and the Fokou valley to the


6A-9

south-west. This suggests a substantial groundwater discharge within these valleys. In all cases, there is initially a significant contribution to regional stream flows from the mountain, which diminishes downstream at a rate that depends on the growth in catchment area and the frequency and magnitude of tributary inflows. The relative importance of the mountain flow contribution reduces most quickly in the Loffa, Diani and Mala river catchments. Moreover, there is evidence of a fairly dynamic system of flow accretion and loss occurring along most of the streams moving away from the mountain. This further reduces the influence of on-hill groundwater discharges on regional stream flows downstream of the mining area.

Foma

Kankoro

CangaEast

Camp

Orono

LamandouMoribadou

Mamouroudou

Wataférédou II

Wataférédou ITraoréla Siatouro

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Client: Taille: Titre:Légende:Figure 6A.7Ligne de courant dérivées de l’enquête 2008 d’accrétion des courants en saison sèche / Flow Contours Derived From 2008 Dry Season Flow Accretion Survey

Source d'eau répertoriée en saison sèche / Spring Locations (Dry Season Survey)Isocontour de débit (l/s) / Flow Isocontours (l/s)Agglomération / SettlementRoute principale / Primary RoadRoute secondaire / Secondary RoadRoute tertiaire / Tertiary RouteCours d'eau / WatercourseContour de mine / Mine OutlineTerril de stériles / Waste EmplacementForêt classée / Classified Forest


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Approuvé par: KR

Projet: 0131299


24.1 l/s1.3 l/s/km2

0 %

132.5 l/s1.4 l/s/km2

0 %

240.2 l/s1.8 l/s/km2

0 %

124.7 l/s3.3 l/s/km2

0 %

109.3 l/s3.5 l/s/km2

0 %

106.9 l/s6.8 l/s/km2

0 %

2884.4 l/s4.2 l/s/km2

0 %

79.4 l/s2.88 l/s/km2

99 %

152 l/s2.13 l/s/km2

93.9 %

88.4 l/s8.7 l/s/km2

72.6 %

74.2 l/s2.76 l/s/km2

86.5 %

780.1 l/s5.77 l/s/km2

16.2 %

142.1 l/s5.93 l/s/km2

88.9 %

503.5 l/s2.88 l/s/km2

38.6 %

705.8 l/s9.94 l/s/km2

27.5 %

834.2 l/s2.49 l/s/km2

79.5 % 56.4 l/s2.38 l/s/km2

139.4 %

3743.2 l/s3.35 l/s/km2

17.7 %

644.8 l/s10.04 l/s/km2

80.7 %

667.7 l/s12.95 l/s/km2

77.9 %

682.9 l/s14.88 l/s/km2

76.16 %

3718.6 l/s3.66 l/s/km2

17.8 %

161.2 l/s14.85 l/s/km2

93.7 %

Dandano

Kouankan

Touréla

Kakano

Banko

BonodouMandou

Orono

Lamandou

DiagbadouMamouroudou

Biniadou Korèla

Famoila

TraorélaMissamaridou

Vassaou

Tédou 1Gbandou-KongolaKouanko

Kamandou

FassinédouZimodou

SossavaKamiandou N.1

N.10

9°0'0"W

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Figure 6A.8

2009 la saison sèche les résultats d'écoulementd'accrétion enquête (flanc ouest) /2009 Dry Season Flow Accretion Survey Results (Western Flank)


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628.9 l/s Débit / Flow rate

14.0 l/s/km2 Débit normalisé du bassin versant /

76.16 % Contribution de la montagne au débit /

Catchment Normalised Flow Rate

Flow Contribution from Mountain

Mesures de débit régional / Regional Flow Measurements

Agglomération / Settlement

Rivière dans le bassin versant colline / River in Hillside Catchment

Rivière dans le bassin versant non-colline / River in Off-Hill Catchment

Contour de mine / Mine Outline

Terril de stériles / Waste Emplacement

Route principale / Primary Road

Route secondaire / Secondary Road

Route tertiaire / Tertiary Route

Bassin versant / Catchment

57.5 l/s6.1 l/s/km2

0 %

65.4 l/s4.8 l/s/km2

0 %

411.6 l/s3.9 l/s/km2

0 %

288.9 l/s2.8 l/s/km2

0 %

202.4 l/s3.4 l/s/km2

0 %

42.7 l/s4.14 l/s/km2

32.8 %

82.3 l/s6.83 l/s/km2

93.9 %

277.8 l/s6.01 l/s/km2

50.1 %

66.8 l/s5.25 l/s/km2

105.3 %

964.1 l/s6.64 l/s/km2

33.4 %

589.2 l/s3.86 l/s/km2

52.3 %

454.3 l/s4.96 l/s/km2

67.9 %

221.2 l/s6.95 l/s/km2

68.3 %

234.3 l/s3.69 l/s/km2

64.5 %

108.4 l/s6.05 l/s/km2

145.1 %

259.8 l/s8 l/s/km2

53.6 %

161.2 l/s14.85 l/s/km2

93.7 %

63 l/s5.81 l/s/km2

111.6 %

SogbéniDomanidou

Foma

Fandou

ManankoroKankoro

KokounaKoimoridou

CangaEast

Camp

Kollako-MoussadouWawakoroBanankoroMafindouMoribadou

GoékoroMamoridouThia

Manakoro

BoubaroWataférédou II

KabakoroNiadou

Wataférédou I BobaroSiatouro

MorisangarédouBoulaydou Kéoulendou

Beyla

PiyaroKouwandala

Bangalydou NyelaTourela

SoumailadouDoukourelaSibiridou

Moussadou

KissiboulaN.1N.1

N.1

8°40'0"W

8°40'0"W

8°50'0"W

8°50'0"W

8°4

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520000

520000

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9400

00

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Figure 6A.9

2009 la saison sèche les résultats d'écoulementd'accrétion enquête (flanc est) /2009 Dry Season Flow Accretion Survey Results (Eastern Flank)


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Vérifié par: TS

Approuvé par: KR

Projet: 0131299


Mesures de débit régional / Regional Flow Measurements


Rivière dans le bassin versant colline / River in Hillside Catchment

Rivière dans le bassin versant non-colline / River in Off-Hill Catchment







628.9 l/s Débit / Flow rate

14.0 l/s/km2 Débit normalisé du bassin versant /

76.16 % Contribution de la montagne au débit /

Catchment Normalised Flow Rate

Flow Contribution from Mountain


6A-13

6A.2 Surface Water Quality

6A.2.1 Water Quality Standards The following international guidelines have been referenced during the course of the surface water impact assessment. International Finance Corporation (IFC) Environment, Health and Safety (EHS) Guidelines for Mining

(December, 2007). IFC General EHS Guidelines for Environmental Wastewater and Ambient Water Quality (April 2007). World Health Organisation (WHO) Guidelines for Drinking Water Quality (4th Edition, 2011). The various water quality / effluent standards that are contained in these guidelines are reproduced in Tables 6A.4 to 6A.6. In the case of the WHO guidelines, there are over 100 individual chemicals listed as having health significance in drinking water and the guidelines recommend that an appropriate sub-set is chosen for monitoring based upon local conditions. Table 6A.6 summarises the guideline standards for some the most commonly used parameters for a project in this setting, in addition to which the guideline values for the specific parameters sampled during the project water quality monitoring campaign are presented in Tables 6A.7 and 6A.8. Table 6A.4 IFC Effluent Guidelines for Mining

Pollutant Unit Guideline Value

Total Suspended Solids mg/L 50

pH S.U. 6 – 9

COD mg/L 150

BOD5 mg/L 50

Oil and Grease mg/L 10

Arsenic mg/L 0.1

Cadmium mg/L 0.05

Chromium (VI) mg/L 0.1

Copper mg/L 0.3

Cyanide mg/L 1

Cyanide Free mg/L 0.1

Cyanide WAD mg/L 0.5

Iron (total) mg/L 2.0

Lead mg/L 0.2

Mercury mg/L 0.002

Nickel mg/L 0.5

Phenols mg/l 0.5

Zinc mg/L 0.5

Temperature OC <3 degree differential

Notes: Metals concentrations represent total metals Source: Table 1, IFC EHS Guidelines for Mining, December 2010


6A-14

Table 6A.5 IFC Guidelines for Treated Sanitary Sewage Discharges

Pollutant Unit Guideline Value

pH S.U. 6 – 9

BOD mg/l 30

COD mg/l 125

Total nitrogen mg/l 10

Total phosphorus mg/l 2

Oil and grease mg/l 10

Total suspended solids mg/l 50

Total coliform bacteria MPN / 100 ml 400

Notes: MPN – Most probable Number Source: Table 1.3.1, IFC General EHS Guidelines for Environmental, Wastewater and Ambient Water Quality, April 2007

Table 6A.6 Selected WHO Drinking Water Guidelines

Parameter Unit Guideline Value

Total coliforms per 100 ml Zero in treated water

Cadmium mg/l 0.003

Cyanide mg/l 0.5

Mercury mg/l 0.006

Selenium mg/l 0.04

Arsenic mg/l 0.01

Fluoride mg/l 1.5

Nitrate (as NO3-) mg/l 50

Source: WHO Guidelines for Drinking Water Quality, 4th Edition, 2011

6A.2.2 Water Quality Monitoring Campaign A comprehensive baseline water quality monitoring campaign has been ongoing in the vicinity of the Pic the Fon and Ouéléba deposits and close to villages downstream since November 2006. This campaign is described in detail in the baseline reports listed in Chapter 6: Water Environment, Section 6.3. The surface water quality monitoring network is shown in Figure 6.3 of the chapter and consists of 13 spring and 24 stream sampling stations. Twice daily records of flow, water colour and turbidity were also initiated in early 2008 at 18 monitoring locations near villages, with measurements taken upstream and downstream of community water collection points. In addition, continuous monitoring of turbidity, temperature, conductivity, dissolved oxygen and pH was conducted at a number of weirs equipped with automatic systems. Detailed sampling of Total Suspended Solids (TSS) in natural stream waters was added to the programme in late 2008. In addition, 140 spot samples of water have been collected from a number of streams during or shortly after storm events for turbidity and TSS analyses. The surface water samples collected in the course of the sampling campaigns typically presented very low ionic concentrations. Due to the general lack of statistical variability within the results, the main physico-chemical results have been compiled and presented as summary statistics for springs and streams. Since surface water may be used as drinking water, standards from the World Health Organisation (WHO) Guidelines for Drinking Water Quality (4th edition, 2011) have also been presented in the tables for reference. Spring Water Quality Summary statistics for spring water quality are shown in Table 6A.7. According to the data shown, the spring water samples display the characteristics of water with very little mineralisation. Most of the parameters, including major anions and cations and trace metals, are below detection limit or present at very low


6A-15

concentrations. All parameters are below the WHO guideline limits, although it is apparent that the water is generally acidic in quality with a median pH value of 4.0 (1). This could be due to carbonic acid generation in low ionic strength water, but is thought more likely due to the process of sulphide oxidation as the water passes through the acid-generating phyllite materials that are abundant in the local geology (WMC 2009b). The spring samples present the lowest solute concentrations among all water samples collected in the study area. Stream Water Quality Summary statistics for stream water quality are shown in Table 6A.8. They exhibit slightly higher solute contents in comparison with upstream spring samples. Electrical conductivity readings correspond to total dissolved solids values between 2 and 100 mg/l, characteristic of essentially pure water. The pH values for the stream samples are less acidic than the very low values measured for the upstream spring samples, with a median pH value of 5.7, indicating that the acidity is emanating from the springs. The major ion and trace element concentrations pattern for stream samples is similar to the spring samples, with values measured below detection limit, or present at very low concentrations. Median concentrations in stream samples are approximately twice the median levels measured in springs. The sample concentrations measured in the stream samples also fell below WHO guidelines for all parameters. Table 6A.7 Summary of Spring Water Chemistry Across the Mine Site

Parameter Unit Method

Detection Limit

Minimum Maximum Median WHO

Guideline Limit [1]

Temperature oC - 17.9 27 21.4 -

pH pH unit - 1.2 9.6 4 -

ORP mV - -248 629 168 -

DO mg/l - 0.6 12.5 6 -

EC μS/cm - 2 22 8 -

Turbidity NTU 0.1 0.1 22.8 0.9 -

Ca mg/l 0.7 0.35 1.3 0.35 -

Na mg/l 0.005 0.093 1.26 0.23 50

K mg/l 0.03 0.04 0.96 0.215 -

Mg mg/l 0.001 0.027 0.758 0.203 -

Cl mg/l 0.03 0.015 1.35 0.135 5

SO4 mg/l 0.03 0.015 0.55 0.055 -

CO3 mg/l - 0 0 0 -

HCO3 mg/l - 6.5 0.1 1.1 -

NO3 mg/l 0.01 0.005 0.44 0.005 50

NO2 mg/l 0.01 0.005 0.005 0.005 3

PO4 (as P) mg/l 0.02 0.01 1.46 0.01 -

Ammonia mg/l 0.02 0.01 0.18 0.01 -

TOC mg/l 0.01 0.1 4.27 0.795 -

Si mg/l 0.2 0.5 4.3 3.05 -

F μg/l 10 5 400 5 1 500

Li μg/l 1 0.5 1 0.5 -

Fe μg/l 10 5 180 5 -

(1) WHO do not provide a guideline value for pH, although it is recognised as an important parameter for water supply systems. The spring and stream quality data typically fall below normal operating guidelines (6.5 to 8.5) and so would require pH adjustment within any potable water supply system.


6A-16


Detection Limit


Guideline Limit [1]

Mn μg/l 0.1 0.05 11.9 1.95 -

Ni μg/l 0.3 0.15 8.2 0.15 70

Ag μg/l 0.2 0.1 0.1 0.1 -

Al μg/l 2 1 77 12 -

As μg/l 0.03 0.015 0.53 0.015 10

Hg μg/l 0.2 0.1 0.1 0.1 6

Cr μg/l 0.5 0.25 0.25 0.25 50

Ba μg/l 0.1 2.1 38.7 4.15 700

Br μg/l 3 1.5 14 1.5 -

Cd μg/l 0.01 0.005 0.02 0.005 3

Cu μg/l 0 0.1 1.4 0.1 2 000

Pb μg/l 0.01 0.005 1.38 0.03 10

Sr μg/l 0.04 1.14 11.4 2.78 -

Zn μg/l 0.5 0.25 29 0.8 -

U μg/l 0.001 0.0005 0.029 0.0005 30

Be μg/l 0.1 0.05 0.05 0.05 -

Se μg/l 0.2 0.1 0.2 0.1 40

Sn μg/l 0.1 0.05 0.2 0.05 -

Co μg/l 0.005 0.0025 0.436 0.0665 -

Notes: [1] Taken from WHO guideline values for chemicals that are of health significance in drinking-water (WHO Guidelines for Drinking Water Quality, 4th Edition, 2011) - Values less than the detection limit and have been reset to half of the detection limit for purposes of calculating summary statistics. Source: Social and Environmental Baseline Study (Mine Component): Volume C – Physical Baseline, SNC Lavalin Environment, August 2010

Table 6A.8 Summary of Stream Chemistry Across Mine Site


Detection Limit


Guideline Limit [1]

Temperature oC - 15.8 25.6 20.55 -

pH pH unit - 2.1 9.1 5.65 -

ORP mV - -267 680 76.6 -

DO mg/l - 0.6 72 6.6 -

EC μS/cm - 3 140 15 -

Turbidity NTU 0.1 0.2 69.7 2.5 -

Ca mg/l 0.7 0.35 11.6 0.9 -

Na mg/l 0.005 0.12 8.98 1 50

K mg/l 0.03 0.04 10.2 0.635 -

Mg mg/l 0.001 0.14 4.86 0.7 -

Cl mg/l 0.03 0.03 7.79 0.205 5

SO4 mg/l 0.03 0.015 15.4 0.185 -

CO3 mg/l - 0 0 0 -

HCO3 mg/l - 80 1.6 5.5 -

NO3 mg/l 0.01 0.005 262 0.005 50


6A-17


Detection Limit


Guideline Limit [1]

NO2 mg/l 0.01 0.005 0.07 0.005 3

PO4 (as P) mg/l 0.02 0.01 15.1 0.01 -

Ammonia mg/l 0.02 0.01 0.2 0.01 -

TOC mg/l 0.01 0.4 8.25 1.5 -

Si mg/l 0.2 1.5 20.3 5.25 -

F μg/l 10 5 230 5 1 500

Li μg/l 1 0.5 2 0.5 -

Fe μg/l 10 5 2510 75 -

Mn μg/l 0.1 0.05 1 000 3.55 -

Ni μg/l 0.3 0.15 0.7 0.15 70

Ag μg/l 0.2 0.1 0.1 0.1 -

Al μg/l 2 1 64 11 -

As μg/l 0.03 0.015 0.21 0.06 10

Hg μg/l 0.2 0.1 0.1 0.1 6

Cr μg/l 0.5 0.25 0.25 0.25 50

Ba μg/l 0.1 2 209 22.1 700

Br μg/l 3 1.5 22 1.5 -

Cd μg/l 0.01 0.005 0.03 0.005 3

Cu μg/l 0.2 0.1 1.2 0.1 2 000

Pb μg/l 0.01 0.005 3.9 0.04 10

Sr μg/l 0.04 2.25 118 10.95 -

Zn μg/l 0.5 0.25 10.9 1.1 -

U μg/l 0.001 0.0005 0.155 0.005 30

Be μg/l 0.1 0.05 0.05 0.05 -

Se μg/l 0.2 0.1 0.1 0.1 40

Sn μg/l 0.1 0.05 0.05 0.05 -

Co μg/l 0.005 0.0025 2.52 0.031 -

Notes: [1] Taken from WHO guideline values for chemicals that are of health significance in drinking-water (WHO Guidelines for Drinking Water Quality, 4th Edition, 2011) - Values less than the detection limit and have been reset to half of the detection limit for purposes of calculating summary statistics. Source: Social and Environmental Baseline Study (Mine Component): Volume C – Physical Baseline, SNC Lavalin Environment, August 2010 In addition to the ongoing water quality monitoring described above a survey of village surface water drinking points was carried out in January / February 2008, which included water quality sampling. The water quality results from this survey are shown in Table 6A.9.


6A-18

Table 6A.9 Summary of Surface Water Use Survey at Villages Near Mine in February 2008

Village/River Faecal coliforms

(No./100 ml)

pH Cond.

(μS/cm)

Temp.

(0 C)

Diss.

Oxygen

(mg/l)

Redox

Potential

mV

Turbidity

TU

Flow

l/s

Water use Alternative water sources

Banankoro

Siankoun Gbe 220-260 6.0 57 24.1 6.3 52.6 5 48 Washing clothes, bathing, construction, drinking water, livestock watering.

Either river for washing and bathing. The tubewell with handpump and Mosque well in Banankoro village for drinking and cooking water.

Siankoum Fin 220-260 6.2 57 23.5 5.9 46.8 5 28

Banko

Pulowaye River - 6.76 18 21.5 - 48.5 <5 104 Washing clothes, bathing, construction, drinking water, livestock watering.

Tubewell with handpump, Forest Centre well and Adama Traoré well.

Foma

Loffa River 161-183 6.8 57 16.2 7.9 16.5 <5 580 Washing clothes, bathing, construction, drinking water, livestock watering.

None.

Boe River >250 6.8 42 16.5 7.3 20.3 8 38

Seniyeworo River 73-132 6.4 51 15.8 7.6 20.1 <5 8

Kakano

Soumourou River 306-310 5.7 32 22.6 7.6 78.6 15 890 Washing clothes, bathing, construction, drinking water, livestock

None.


6A-19


(No./100 ml)

pH Cond.

(μS/cm)

Temp.

(0 C)

Diss.

Oxygen

(mg/l)

Redox

Potential

mV

Turbidity

TU

Flow

l/s


watering.

Kotila

Torokoroko River 170-190 5.9 33 20.5 3.8 44.0 5 31 Washing clothes, bathing, construction, drinking water, livestock watering.

Whisky 1 stream.

Djitako River 180-220 6.5 108 21.6 7.1 -0.6 5 13

Lamadou

Worongbe River 2-30 6.1 14 20.9 7.8 19.2 <5 114 Washing clothes, bathing, construction, drinking water, livestock watering.

None.

Mafindou

Kouwan River 265-288 6.3 35 21.0 6.2 53.1 <8 11 Washing clothes, bathing, construction, drinking water, livestock watering.

Mamadi Camara well in Mafindou village. Korou Kony River 852-938 5.1 46 22.2 4.11 89.1 <5 -

Djibi Koni River 815-930 6.7 30 28.2 6.1 53.7 <5 1

Mandou

Woron River 58-92 6.27 20 23.10 - 157.6 <5 641 Washing clothes, bathing, construction, drinking water, livestock watering.

Two wells and a tubewell with handpump in Mandou.


6A-20


(No./100 ml)

pH Cond.

(μS/cm)

Temp.

(0 C)

Diss.

Oxygen

(mg/l)

Redox

Potential

mV

Turbidity

TU

Flow

l/s


Mamourdou

Woron River 122-130 6.1 34 22.4 6.1 65.1 <5 - Washing clothes, bathing, construction, drinking water, livestock watering.

Toubaboukonin River and Banankonin River, both distant from village.

Nionsomoridou

Miya River 121-135 5.8 39 19.8 7.9 55.2 <8 233 Washing clothes, bathing, construction, drinking water, livestock watering.

Three tubewells with handpumps, six properly constructed wells and six poorly constructed wells, all in Nionsomoridou Village.

Orono

Woron River - 3.2 36 22.1 7.8 373.4 <5 478 Washing clothes, bathing, construction, drinking water, livestock watering.

None.

Borongo River 129-137 5.9 40 20.5 6.3 78.9 12 -

Siatouro

Boboyba River 123-168 6.0 22 21.6 8.0 56.1 <5 64 Washing clothes, bathing, construction, drinking water, livestock watering.

None.


6A-21


(No./100 ml)

pH Cond.

(μS/cm)

Temp.

(0 C)

Diss.

Oxygen

(mg/l)

Redox

Potential

mV

Turbidity

TU

Flow

l/s


Touréla

Dianiworo River 190-205 5.7 28 20.0 8.5 107.0 <5 7 Washing clothes, bathing, construction, drinking water, livestock watering.

One tubewell with handpump and N'Fo Sory well in Touréla village.

Tourekonin - 5.69 28 20.08 8.53 107 – -

Traoréla

Mala River 206-220 6.2 40 23.4 6.0 39.9 32 76 Washing clothes, bathing, construction, drinking water, livestock watering.

One tubewell with handpump in Traoréla village.

Kinyeko River 536-569 4.7 16 21.2 7.2 127.3 12 63

Mokounko River 160-189 6.5 40 22.8 6.5 46 11 17

Wataférédou

Wataférédou

Farako

156-255 6.65 411 23.01 0.88 47.1 15 - Washing clothes, bathing, construction, drinking water, livestock watering.

One tubewell with handpump in Wataférédou village.

Watakonin 195-260 4.97 96 19.77 2.23 62.5 <5 -


6A-22

Sediment Monitoring Project investigations have revealed that early site activities already undertaken (access road and drill-pad construction in particular) have produced quantities of sediment that has been transported into streams by overland flow during storms. Figure 6A.10 shows the stream reaches which have been found to be affected, and also distinguishes in a very general way between natural and ‘disturbed’ catchments across the project area. In order to distinguish between ‘natural’ and ‘disturbed’ baseline conditions, automatic and spot sampling TSS data have been collected since early 2009 from several locations shown in Figure 6A.10. These data are presented in Table 6A.10, and Figure 6A.11 presents the variations in turbidity at Whisky 1 during storm events. As observed, periods of high turbidity are clearly associated with increased flow. The results also indicate that, whilst there is significant variability in both cases, the TSS in the surface waters from disturbed catchments is higher. Upstream versus downstream differences in turbidity have also been observed at a number of villages, suggesting an influence from the activities of the communities themselves. Similarly, the influence of communities on water colour is observed in 60% of the sampling sites, where upstream clear water, for example, turns to light brown downstream (Table 6A.11).

Domanidou

Foma

Touréla

Kakano

KankoroBanko Koimoridou

CangaEast

Camp

BonodouMandou

Orono

Lamandou MafindouMoribadou

Thia

Mamouroudou

KorèlaWataférédou II

Famoila

Wataférédou I BobaroTraoréla Siatouro

Vassaou

Boulaydou

NionsomoridouKouwandala

Kamandou

Fassinédou Bangalydou

Gbagbadou

Soumailadou

SibiridouSossava

Kamiandou

Kissiboula

Pic de Fon(1656m)

Pic duOueleba(1330m)

N.1 N.1

N.1

8°50'0"W

8°50'0"W

9°0'0"W

9°0'0"W

8°4

0'0

"N

8°4

0'0

"N

8°3

0'0

"N

8°3

0'0

"N

500000

500000

510000

510000

520000

5200009300

00

9300

00

9400

00

9400

00

9500

00

9500

00

9600

00

9600

00

9700

00

9700

00

CLIENT: Taille: Titre:Légende:

A4 Figure 6A.10

Flux affectés par le ruissellement des sédiments dans le zone minière / Streams Affected by Sediment Runoff in Mining Area

Sites d'échantillonnage des sédiments / Sediment Sampling Locations

Automatique / Automatic

Point / Spot

Haute altitudes / Highest Elevation





Bassin versant du Niger / Niger Watershed




Cours d'eau principal / Primary Watercourse

Drainage possibles / Possible Drainage

Trajectoire des sediments / Stream Sediment Path

Inférée / Inferred

Observées / Observed

Pas de sédiments / No Sediment

PROJECTION: WGS 1984 UTM Zone 29N

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M a l iM a l i






6A-24

Figure 6A.11 Variations in Turbidity at Whisky 1 During Storm Events

Table 6A.10 Total Suspended Solids (TSS) in Natural and Disturbed Catchments

Percentile TSS (mg/l)

Natural catchments Disturbed catchments

95 127 374

75 (upper quartile) 51 108

50 (median) 24 36

25 (lower quartile) 5 17

5 1 3

Table 6A.11 Frequency (%) of Twice-Daily Observations of Stream Water Colour at Villages

Location Record Period

Upstream of Water use (10-20 m) Downstream of Water use (10-20 m)

Clear Light Brown

Dark Brown

Red Clear Light Brown

Dark Brown

Red

Mala at Traoréla 23 Jan-30 Nov 08

45 44 10 1 39 49 10 1

Kinyeko at Traoréla 23 Jan-30 Nov 08

52 32 6 10 42 40 9 10

Miya at Nionsomoridou 17 Jan-31 Aug 08

72 19 1 8 34 56 2 8

Loffa at Canga East

Road

1 Feb-30 Nov 08

61 28 5 6 53 36 5 6

Tamanko at Canga

East Road

13 Apr-30 Nov 08

56 29 8 7 47 37 7 9


6A-25

Location Record Period

Upstream of Water use (10-20 m) Downstream of Water use (10-20 m)

Clear Light Brown

Dark Brown

Red Clear Light Brown

Dark Brown

Red

Loffa at Foma

29 Jan-31 Oct 08

38 35 14 13 38 35 11 16

Boe at Foma

30 Jan-31 Oct 08

64 26 5 5 62 28 4 6

Worongbe at

Lamadou

30 Jan-30 Nov 08

89 9 2 0.2 44 55 1 0.3

Woron at

Mamourdou

20 Feb-31 Aug 08

44 51 5 0 43 52 5 0

Woron at Orono

17 Feb-31 Oct 08

71 22 2 5 70 22 2 6

Woron at Mandou

9 Feb-31 Aug 08

73 18 5 4 73 18 5 4

Pulowaye at Banko

13 Feb-31 Oct 08

49 22 27 2 41 28 29 2

Dianiworo at Touréla

20 Feb-31 Aug 08

81 3 13 3 81 4 13 2

Soumourou at Kakano 20 Feb-30 Nov 08

- - - - 18 31 32 19

Farako at Canga East

Road crossing

12 Apr-30 Nov 08

63 25 7 5 53 29 7 11

Farako at Wataférédou 23 Feb-30 Nov 08

64 19 15 2 57 21 20 2

Siankounfin at

Banankoro

16 Apr-31 Oct 08

67 17 16 0 62 19 19 0

Siankoungbe at

Banankoro

16 Apr-31 Oct 08

74 14 12 0 75 15 10 0

6A.3 Surface Water Users Table 6A.12 summarises the results of the surface water use survey that was conducted for villages in the immediate proximity of the mine, including the types of water use and flow conditions at the time of the survey. Reported water uses included domestic supply, fabricating bricks, livestock watering and fishing. In addition, a detailed survey of the quantity of surface water being used at three representative villages was carried out in February 2008. Table 6A.12 indicates that the rivers are being fairly widely used for supply purposes, but that the volumes abstracted each day are relatively small in comparison to the total daily flow in the rivers.


6A-26

Table 6A.12 Surface Water Use at Selected Villages in February 2008

Location Volume Collected

(litres) [1] Approximate %

daily flow volume [2] Approximate

no. of families Uses

Mafindou, 25 February 2008

Kouwan River 5 654 0.6% 14 Cooking , drinking, washing

Korou Kony River 1 025 - 3 Cooking , drinking, washing, construction

Djibi Koni River 1 275 1.5% 10 Cooking , drinking, washing, construction

Moribadou, 26 February 2008

Danako River 3 223 - 9 Cooking , drinking, washing

Djitako River 10 021 - 9 Cooking , drinking, washing, construction

Kobano River 841 - 10 Cooking , drinking, washing, construction

Plantation River 893 - 7 Cooking , drinking, washing, construction

Traoréla, 27 February 2008

Mala River 998 <0.1% 8 Cooking , drinking, washing, construction

Kinyeko River 3 012 <0.1% 10 Cooking , drinking, washing, construction

Notes: [1] These volumes were surveyed over an approximate 10 to 12 hour period during the day at each location. [2] Approximate percentages have been calculated where possible based upon the flows measured in Jan / Feb 2008, as shown in Table 6.8. Source: Baseline Hydrology Report (Mine Component), WMC, February 2009. With respect to agricultural water use, although the water point survey did not include irrigated (principally rice-growing) lands, it is possible to estimate water usage from available land use maps and knowledge of local cropping methods and crop water requirements. Chapter 6: Water Environment, Figure 6.5 shows the areas of ‘agricultural plain’ where it has been assumed that irrigated rice cultivation is taking place, and Table 6A.13 summarises the estimated irrigation water demand in May when the fields are wetted ready for transplantation. A comparison of agricultural water use estimates with the village water use data shown in Table 6A.12 suggests that the former is significantly higher, potentially by several orders of magnitude. Table 6A.13 Estimated Irrigation Demands vs Stream Flows During May

Location Irrigated Area (ha)

Estimated Irrigation Demand (m3/s)

Measured Mean Flow in

May 2008 (m3/s)

Estimated Flow in 1-in-5

Dry Year (m3/s)

Irrigation Demand as % of May flow

May 2008 Dry Year

Kinyeko at Traoréla 13.8 0.012 0.040 0.026 29 45

Woron at Orono 75.7 0.065 0.531 0.350 12 18

Woron at Mandou 122.4 0.104 0.693 0.457 15 23

Loffa at Canga East Road 38.6 0.033 0.282 0.186 12 18

Loffa at Foma 108.9 0.093 2.564 1.692 4 5

Boe at Foma 39.5 0.034 0.075 0.050 45 68


6A-27

6A.4 Groundwater Modelling Results The following figures summarise the preliminary groundwater modelling results that have informed the impact assessment described in Chapter 6: Water Environment, Section 6.4.1. It is stressed that the flow effects described above are all pre-mitigation (ie without taking into account any dewatering discharges) and are based on preliminary model results only. Figure 6A.12 shows the existing average (1) baseflow distribution across the various catchments that

drain the Ouéléba and Pic de Fon mining sites, as estimated by the groundwater model.

Figure 6A.13 shows the predicted total dewatering rates that will be required for the Ouéléba and Pic de Fon ore bodies over their full mine life (approximately 45 and 25 years respectively). The figure also shows the modelled reduction (shortfall) in total baseflow to the various catchments draining from the mine sites caused by dewatering, and the consequent ‘surplus’ flow that would be available assuming that all of these baseflows were replenished to their existing levels using the dewatering abstractions.

Figures 6A.14 and 6A.14 show the estimated magnitude of the effects on stream baseflows at Ouéléba and Pic de Fon in early and late mine life prior to any dewatering abstractions being discharged into the streams as part of impact mitigation.

Figures 6A.16 to 6A.19 shows the estimated magnitude of the effects on streams baseflows and the

predicted formation of pit lakes following mine closure at both locations.

(1) Average conditions are represented in the model by February baseflows, which in hydrological terms are a close approximation to the average of wet and dry season conditions.


6A-28

Figure 6A.12 Existing Average Stream Baseflows (l/s) Estimated By Model

Ouéléba Pic de Fon


6A-29

Figure 6A.13 Predicted Dewatering Rates and Stream Responses


6A-30

Figure 6A.14 Ouéléba Modelling Results – Baseflows Following Dewatering (% Existing Baseflow)

Year 10 (Early Mine Life) Year 45 (Late Mine Life)


6A-31

Figure 6A.15 Pic de Fon Modelling Results – Baseflows Following Dewatering (% Existing Baseflow)

Year 10 (Early Mine Life) Year 25 (Late Mine Life)

Lamandou

Traoréla

Kinyeko

KinyekoTrib1

KinyekoTrib2

Loffa1

Mala 1

Mala 2

Mala 3

Miya1

Miya2

Miya2trib

Miya3

Miya4

Whisky 6

Woron1-N

Woron1-S

Woron2-N

Woron2-N trib1


Figure 6A.16

Position des lacs artificiels et courant des eaux de surfaces suite à la fermeture, Ouéléba /Location of Pit Lakes and Surface Water Flow Post Closure, Ouéléba

Nouvelle zone de bassin versant / New Catchment Zone




Terrain (mRL) / Ground (mRL)

500

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1500

1600


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Direction de l'écoulement / Flow Direction


C o t eC o t e

d ' I v o i r ed ' I v o i r e


LamandouMoribadou

Wataférédou II

Traoréla Siatouro

543

20

29

16

61

26

21

18

16

32

46

53

2522

87

10 6

15

31

382

19

29

17

39

20

21

15

16

30

89

81

23

19

87

10 6

15

17Kinyeko

KinyekoTrib1

KinyekoTrib2

Loffa1

Loffa2

Loffa3

Loffa3trib

Mala 1

Mala 2

Mala 3

Miya1

Miya2

Miya2trib

Miya3

Miya4

Whisky 6

Woron1-N

Woron1-S

Woron2-N

Woron2-Ntrib1

Woron2-Ntrib2

Woron2-Ntrib3


Figure 6A.17

Courant de référence du bassin versant après fermeture, Ouéléba / Catchment Baseflows Post Closure, Ouéléba

Nouvelle zone de bassin versant /New Catchment Zone

Contour géologique /Geology Outline

Contour de mine /Mine Outline


Profondeur des remblais (m) / Backfill Depth (m)

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Date: 06/06/2012

Dessiné par: WB

Vérifié par: TS

Approuvé par: KR

Projet: 0131299


Courant de référence (l/s) après fermeture /Baseflows (l/s) Post-Closure

Niveau de référence des courants (l/s) /Baseline Baseflows (l/s)


C o t eC o t e



CangaEast

Camp

Boe

Dianiworo1

Dianiworo2

FokouEast

FokouEast-N

FokouWest

Loffa3

Loffa3trib

Loffa4

Pulowaye

WesternSpur

Whisky 1

Whisky1-N

Whisky1-N trib

Whisky 3

Whisky 4

Whisky4 trib

Whisky4-N

Whisky4-S

Woron2

Woron2-Ntrib3


Figure 6A.18

Position des lacs artificiels et courant des eaux de surfaces suite à la fermeture, Pic de Fon /Location of Pit lakes and Surface Water Flow Post Closure, Pic de Fon

Nouvelle zone de bassin versant / New Catchment Zone





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Date: 06/06/2012

Dessiné par: WB

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Approuvé par: KR

Projet: 0131299


Terrain (mRL) / Ground (mRL)

500

600

700

800

900

1000

1100

1200

1300

1400

1500

1600

Profondeur de remblayage (m) / Backfill depth (m)

30 60 9012

015

018

021

024

027

030

033

036

0

Profondeur du lac (m) / Lake depth (m)

10 20 30 40 50 60 70 80 9010

011

012

013

014

015

0

Direction de l'écoulement / Flow Direction


C o t eC o t e



CangaEast

Camp

Boe

Dianiworo1

Dianiworo2

FokouEast

FokouEast-N

FokouWest

Loffa3

Loffa3trib

Loffa4

Pulowaye

WesternSpur

Whisky 1

Whisky1-N

Whisky1-N trib

Whisky 3

Whisky 4

Whisky4 trib

Whisky4-N

Whisky4-S

Woron2

Woron2-Ntrib3

11

13

64

135

168

25

44

14

208

57

93

17

13

9

17

40

12

13

60

135

172

25

45

14

186

57

93

17

12

9

15

40


Figure 6A.19

Courant de référence du bassin versant après fermeture, Pic de Fon /Catchment Baseflows Post Closure, Pic de Fon

Nouvelle zone de bassin versant /New Catchment Zone

Contour géologique /Geology Outline

Contour de mine /Mine Outline


Profondeur des remblais (m) / Backfill Depth (m)

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260


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0 1

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Date: 06/06/2012

Dessiné par: WB

Vérifié par: TS

Approuvé par: KR

Projet: 0131299


Courant de référence (l/s) après fermeture /Baseflows (l/s) Post-Closure

Niveau de référence des courants (l/s) /Baseline Baseflows (l/s)


C o t eC o t e



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