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Mr Charlie Berrington Transmission via: email AE AMD renewable energy Level D, The Adderley, 25 Adderley Street Your Ref.: Welcome Wood P. O. Box 2681, Cape Town, 8000 Our Ref.: 834/09/02/2013 Date: 28 October 2013 Dear Mr. Berrington

AE AMD GROUNDWATER FEASIBILITY STUDY: WELCOME WOOD PV POWER PLANT

1. INTRODUCTION Umvoto has been appointed to assess the groundwater potential of the Welcome Wood Site in the to determine groundwater potential with the aim of supplying water for the construction and operation of two solar power plants on the site. The Welcome Wood project has obtained authorization to develop a 3 MW plant on Portion 5 of the Farm 457. However, at the farm owners request, an EIA is in process to develop two 3 MW PV power plants on portion 4 of the Farm 457. The projects would require 500 kl of water for the construction phase and 500 kl/annum during the operational phase for each of the 3 MW plants (total of 1 Ml/annum).

2. LOCALITY The Welcome Wood Site is located 2 km northeast of the R385 between Postmasburg and in the Northern . The site is accessed via a dirt road off the R385 and the closest settlement is Owendale. The site occurs south of southwest of Danielskuil, northwest of Lime Acres and east of Postmasburg. The site location is show in Figure 1.

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Figure 1: A. Locality of the Welcome Wood Site between Postmansburg, Danielskuil and Lime Acres in the Northern Cape. B. The Welcome Wood site location close to Owendale and the R385. Roads in yellow and towns red dot with white label.

Umvoto Africa (Pty) Ltd. Directors: E R Hay, C J H Hartnady Registration Number: 2001\013609\07 Associates: K Riemann, R Wonnacott

The site occurs on flat, low-lying hills named the Kuruman Hills. These represent a north-south trending narrow band of hills and valleys which run from Prieska to the Botswana border. The hills rise to an elevation of 1750 mamsl from 1450 mamsl in the surrounding valleys which are covered by wind-blown Kalahari sand. The site occurs in the Hay District north of the Orange River on portions 4 and 5 of the Farm 457 close to the abandoned Blue Asbestos Mine. A non-perennial stream occurs to the south of the site and this stream is a tributary of the Klein Riet River which flows in a south east direction into the Vaal River at Schmidtsdrif.

The areas climate is arid with hot summers (average maximum 32˚C) and cold winters (average minimum 5˚C). Air temperatures are however subject to large diurnal and seasonal variations. Mean annual precipitation for the area is between 200-400 mm per annum with rainfall predominantly occurring as thunderstorms in summer between October and March. Monthly rainfall varies between 20-40 mm during the rainy season and 0-10 mm in the dry season. Mean annual pan evaporation is between 2000-3000 mm per annum for the Postmansburg area.

3. GEOLOGY The site is underlain by rocks of the Asbestos Hill Subgroup of the Ghaap Group. The Campbell Rand Subgroup dolomites occur to the east of the site and underlie the Danielskuil area. The sediments of the Makganyene Formation and Ongeluk lavas overlie the Asbestos Hill sediments to the south west of the site.

The Asbestos Hill Subgroup is made up of the Kliphuis banded iron formation (BIF) which is made up of siderite and haematite shales and chert; the Kuruman banded iron formation showing siderite, magnetite and haematite chert, lutite and rhythmites. These formations are overlain by the Danielskuil Formation regarded as a reworked banded iron formation composes of BIF clasts in mudstone and shale layers with amphibolites, jasper and chert beds or lenses. The blue asbestos mineral crocodilite has developed in places and has been mined between Danielskuil and Postmasburg. The site is underlain by the Asbestos Hill Subgroup which reaches thicknesses of 200-1000 m. Age dating of the base of the Danielskuil Formation is proto-Proterozoic as has been dated as having been deposited between 2430 and 2490 Ma (Eriksson et. al 2006).

To the east the Campbell Rand Subgroup dolomites represents a preserved stromatolitic carbonate platform. The dolomites are composed of stromatolitic domes and laminated stromatolites overlain by tuffs, dolomite, oolitic beds, clastic laminated carbonate beds, columnar stromatolites, chert, mat stromatolites and dolarenite with distinct microfossils. This deepening upward series terminates in the banded iron formation of the Ghaap Group sediments. The dolomites have been dated as having been deposited in the end of the Archaean between 2650-2500Ma (Eriksson et. al 2006). This formation reaches thicknesses of between 1600 to 2500 m.

Quaternary windblown sands occur in valleys between the hills formed by the Ghaap Group and surficial limestone has developed towards the east overlying the Campbell Rand Subgroup. The geology underlying the site is show in Figure 3 and the legend for the geology map is shown in Figure 2.

Numerous dolerite dykes and diabase dykes and sills have intruded the dolomite but show limited extent in the Asbestos Hill BIF or shale/mudstone formations (Vermaak & Maoko, 2003 and Leskiewcz, 1981).

The dolomite in the east near the site area represent a shallow dipping anticline and the Asbestos Hill Subgroup overlain by basalts represent a shallow dipping syncline. Magnetic lineaments representing possible faults cross-cut and intersect on the site are evident on the magnetic and

2 structural maps of . The Asbestos Hill formation is extensively jointed, fractured and faulted as can be observed in mine shafts and asbestos mines in the Kuruman Hills (Leskiewcz, 1981).

Colour Description Formation Subgroup Group Supergroup Code Qs Red to light wind blown sand, dune sand Kalahari Ql Surface Limstone Vo Amygdaloidal basalt with interbeds of tuff, jasper, chert Ongeluk and agglomerate Posmasburg Vm Diamictite, banded jasper, siltstone, mudstone, dolomite Makganyene with chert Vad Brown jaspilide and chert with crocidolite and alternating layers of shale and mudstone: riebeckite amphibolite Danielskuil Transvaal developed Asbestos Hill Vak Banded ironstone with bands of amphibolite and lenses Ghaap of flat-pebble conglomerate in places, crocidolite and tuff Kuruman interspersed Vgl Dolomitic limestone with coarsely crystaline dolomite, Campbell Lime Acres chert and lenses of limestone Rand Figure 2: Legend for the geological map shown in Figure 3 (GSSA 1977)

Figure 3: Geological map of the site (from the Postmansburg 2822 1:250 000 geological map). Colours and codes as per the key in Figure 2. Roads and tracks are represented by red and brown lines (GSSA 1977) and the site is shown by a red circle.

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4. HYDROGEOLOGY The site occurs on the western edge of the C92B quaternary catchment (Figure 4) and is underlain by a fracture rock aquifer within BIF, mudstone and shale. Boreholes in these formations with potential yields of between 0.5-2 l/s commonly occur (Cockrell, 2005). Yields of in excess of 2 l/s and as high as 10-40 l/s can often be obtained in often extensively fractured and jointed BIF, shales and mudstones and are well known within mines and mine shafts of the Blue Asbestos Mine where a long-term yield of reportedly 16 000 gallons per hour is listed (or between 40 000-70 000 l/hr) (pers comm J. Steyn and Porszasz, 1965). The BIF aquifer is thought to form a perched aquifer overlying the Karstic dolomite aquifer to the east but fracture connectivity between the two is thought to occur. Dewatering at the asbestos mine and later abstraction for supply to 6 surrounding diamond mines for washing and human use may have lowered the water levels in this aquifer over time. The water level is reported to, currently, be 50 m below ground level (J Steyn, pers comm.). Up until 1981 the Cape Blue Asbestos Mine could supply 14.75 million gallons per month for mining operations, domestic supply and to waste water which is equivalent to 67 million l/month (Leskiewicz, 1981). Depth to groundwater in the BIF and shale/mudstone of the Asbestos Hill Subgroup varies between 40-200 m below surface (Ringside Trading, 2011).

The aquifer at the Blue Asbestos Mine at Owendale is described as ‘fairly good’ and the storage capacity rather large, with an aquifer thickness of 250-310 m (Leskiewicz, 1981). A well-developed fissure zone (groundwater occurrence) was encountered at the 150-160 level during underground mining and estimated outflow at this fault zone is 15 l/s at a depth of 110 m. It was reported that the yield from this fracture was consistent for 3 years from 1978-1981. Groundwater levels in the Owendale area could not be accurately measured due to dewatering and continued groundwater abstraction at the Blue Asbestos Mine and water levels fluctuated considerably. Groundwater was pumped from the No. 3 shaft (No. 69) from 150 m at a rate of 320 m3/hour (88 l/s), of which 39 m3/hour (10 l/s) was treated and pumped to the village of Owendale and used for human consumption. The remainder was used in mine operations or supplied to surrounding mines for use. Prior to this water abstraction, 3 boreholes in Owendale were pumped at 1-1.35 Million m3/year to supply groundwater for domestic use. Shaft 7 (No. 71) was also used for groundwater abstraction at the Blue Asbestos Mine to supply the Warrendale Mine of DCBA and Finsch Diamond mine with 13 m3/hour and 0.4 million m3/year respectively, from 1965 and continued after mine closure in 1981 (Leskiewicz, 1981).

Groundwater quality in the site area is anticipated to be fresh with low to moderate salinity between 70-300 mS/m. Various figures are listed for total dissolved solids in the area and on average are thought to be between 200-449 mg/l. No average composition of groundwater in the BIF or the Asbestos Hills shales/mudstones is available but an environmental impact assessment for several portions of farms near Postmasburg lists the groundwater chemistry of several boreholes within the

Asbestos Hill Subgroup as having a calcium-magnesium-bicarbonate character (Ca-Mg-HCO3) (Ringside trading, 2011). The groundwater shows low salinity, is fresh and of drinking water quality but hard in nature and causes scaling problems with the high calcium concentrations. Table 1 shows this range of compositions compared to the SA acceptable water quality for domestic use.

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Table 1: Typical Water Quality values for Ecca Group and dolerite boreholes compared to DWAF maximum allowable limits for drinking water (Ringside Trading, 2011) Range DWAF Max Analysis Unit (Ringside Allowable Limit Trading, 2011) Sodium (Na) mg/l 5.8-25 5.5-9.5 Potassium (K) mg/l 1.9-2.2 300 Calcium (Ca) mg/l 71-100 2000 Magnesium (Mg) mg/l 41-52 400 Chloride (Cl) mg/l 31-52 400 Sulphate (SO4) mg/l 15-25 600 Nitrate (N) mg/l 3.7-7.2 10 Phosphate (PO4) mg/l <0.1 - Ammonia (NH4) mg/l <0.049 2

A review of Water use Allocation and Registration Management System (WARMS) database and the National Groundwater Archive (NGA) database of registered boreholes in the vicinity of the Welcome Wood show three boreholes near the site. All the boreholes in the databases for the surrounding catchments areas are show in Figure 4.

Figure 4: Quaternary catchments (white lines) for the area surrounding the Welcome Wood site and all NGA and WARMS boreholes in the surrounding catchment areas

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Welcome Wood II upper site Welcome Wood II lower site

Welcome Wood alternate site

Figure 5: Boreholes close to the Welcome Wood site and the settlement of Owendale from the WARMS database

The boreholes closest to the site are shown in Figure 5. Details of these boreholes are listed in Table 2, but none appear to be the 3 boreholes known to occur in the town of Owendale or the mine shaft well. All are registered as agriculture or mining. The 25017525 borehole occurs in the Frances Baard District not the Siyanda District and this borehole shows a low yield, therefore is unlikely to be the Blue Asbestos mine shaft well. Yields from all the boreholes appear to be relatively low.

Table 2: Summary of boreholes surrounding the Welcome Wood Site

Licensed Water BH Depth Yield Water BH Latitude Longitude Yield level Comments (mbgl) (l/s) Quality (m3/year) (mbg) Mapedi borehole used for 25002443 28.26667° 23.4° Unknown 40610 1.3 Unknown Unknown irrigation Murray borehole used for 25004888 28.2129° 23.45° Unknown 15070 0.5 Unknown Unknown irrigation 25014671 28.2129° 23.5° Unknown 21750 0.7 Unknown Unknown Used for irrigation Underground mining water, 25017525 28.25° 23.389247° Unknown 7200 0.2 Unknown Unknown Franes Baard District

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The regional hydrogeological information for the site area indicates that depth to groundwater is between 50-75 m for the Owendale and 25-30 m for the Danielskuil areas. The salinity (electrical conductivity) is in the range 70-150 mS/m, mildly saline and the total dissolved solids (TDS) are in the range 750-1000 mg/l, below the DWAF 1996 maximum allowable limit for salinity (300 mS/m) and within the drinking water quality limit for TDS (1200 mg/l).

The DWA regional data indicates the following: Mean annual recharge from precipitation is 5-10 mm/annum; The groundwater component to baseflow in rivers in this area is negligible; Boreholes in the area have a 40-60% probability of a successful borehole drilled; There is 30-40 % chance of a borehole yielding >2 l/s; The average borehole yield is 0.6-0.8 l/s; and The volume of groundwater that can be sustainably abstracted from the Asbestos Hill Subgroup in this area is 6 000-10 000 m3/km2/annum.

This data is supported by the small amount of data obtained from reports and from communication with Mr Japie Steyn.

5. CONCLUSIONS AND RECOMMENDATIONS The groundwater potential of the Welcome Wood site is moderate to high. The existence of shafts within the closed asbestos mine, which have strong groundwater yield (10-20 l/s) and groundwater depth of approximately 50 m below surface indicates sufficient groundwater on site for the proposed solar power plant. The site area is sufficient in size in size to allow for the required abstraction of 500 kl during construction and 1 Ml/annum during operation of the two 3 MW solar power plants as these requirements are well within the sustainable abstraction of 6 000 – 10 000 m3/km2/annum for this area. It is recommended that: The groundwater level in the shaft be measured and a groundwater sample taken to determine quality. The elevated calcium and magnesium in the groundwater can cause scaling and staining or deposition in and blocking of equipment. Chemical analysis will determine if any constituents need to be removed or the water treated prior to use. Sufficient groundwater is available in the mine shaft but exact yields are unknown. The yield of the shaft should be proven and the shaft test pumped in order to confirm yield and thereby inform decisions regarding equipping of the shaft for groundwater abstraction.

6. REFERENCES Cockrell, C (2005). Groundwater investigation for the expansion of the monitoring network in the Beeshoek and Postmasburg Area. Hydrogeological Report GH4022, Department of Water Affairs, Pretoria, 21pp. Geological Survey of South Africa (1977). 2822 Postmasburg 1:250 000 Geological Series and explanatory notes. Prepared by H.F.G. Moen. Pretoria. Ericksson, P.G., Alterman, W. and Hartzer, F.J. (2006). The Transvaal Supergroup and its percursors. In: Johnson M. R., Anhaeusser C. R. and Thomas R. J. (eds.) The Geology of South Africa. Geological Society of South Africa, Johannesburg/Council for Geoscience, Pretoria, pp.461-499.

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Leskiewicz, A.F. (1981). Groundwater investigation of the Danielskuil Mining Area Drainage Region C-39. Report GH3167, Department of Water Affairs, Pretoria, 41pp. Porszasz, K (1965). Investigation report on Danielskuil Mining Area. Hydrological Report GH3034, Department of Water Affairs, Pretoria, 16pp. Ringside Trading (2011). Environmental Impact Assessment of Farm 431, Portion 1 of Farm Doornfontein 446 and Farm 447, Hay District, Northern Cape. Kimberley, 88pp. Vermaak, H. and Maoko, S. (2003). Groundwater investigation for water provisioning in the Danielskuil Area. Geohydrological Report GH4004. Department of Water Affairs, Pretoria 49pp. We hope this report meets the needs of the Welcome Wood project in assessing groundwater potential for the site. Yours sincerely

Karen Burgers Senior Hydrogeologist Umvoto Africa (Pty) Ltd

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