namib lead and zinc mine 2012-2013 annual report sampling ... · slr ref. 733.14009.00005 report...

Namib Lead and Zinc Mine

2012-2013 Annual Report

Sampling of Monitoring Boreholes at EPL-2902

SLR Project No.: 733.14009.000025

Report No.: 2013-M12

August 2013

Namib Lead and Zinc Mining (Pty) Ltd

P.O. Box 81162

Windhoek

DOCUMENT INFORMATION

Title 2012–2013 : Annual Report Sampling Monitoring Boreholes at EPL-2902

Project Manager Jonathan Church

Project Manager e-mail [email protected]

Author Jonathan Church

Reviewer Arnold Bittner

Client Namib Lead and Zinc Mine (Pty) Ltd

Date last printed 2013/12/05 07:05:00 PM

Date last saved 2013/12/05 07:05:00 PM

Comments

Keywords Namib Lead and Zinc, EPL-2902, Annual Sampling, Monitoring Boreholes

Project Number 733.14009.00002

Report Number 2013-M12

Status Final report

Issue Date August 2013

SLR Environmental Consulting (Namibia) (Pty) Ltd.

SLR Ref. 733.14009.00005 Report No.2013-M12

2012-2013 : Sampling of Monitoring Boreholes at EPL-2902 : Annual Report

August 2013

Page i

2012-2013 : SAMPLING OF MONITORING BOREHOLES AT EPL-2902 : ANNUAL REPORT

CONTENTS

1 INTRODUCTION ................................................................................................................................... 1

1.1 BACKGROUND ................................................................................................................................... 1

1.2 OBJECTIVES OF REPORT ................................................................................................................... 1

2 MONITORING BOREHOLE LOCATIONS ............................................................................................ 1

3 GROUNDWATER QUALITY ................................................................................................................. 2

3.1 SAMPLING PROCEDURES ................................................................................................................... 2

3.2 RESULTS .......................................................................................................................................... 3 3.2.1 MAJOR IONS AND PHYSICAL PARAMETERS ..................................................................................................... 3 3.2.2 METALS ...................................................................................................................................................... 6

4 SUMMARY AND CONCLUSIONS ...................................................................................................... 16

5 REFERENCES .................................................................................................................................... 16

LIST OF FIGURES

FIGURE 1: LOCATIONS OF MONITORING BOREHOLES .................................................................................. 2

FIGURE 2: TIME SERIES OF WATERLEVELS IN BOREHOLES SAMPLED ...................................................... 3

FIGURE 3: ANNUAL TDS CONCENTRATIONS IN BOREHOLES SAMPLED ..................................................... 4

FIGURE 4: TIME SERIES TDS DATA FOR NAMIB LEAD & ZINC MINE ............................................................. 4

FIGURE 5: PIPER DIAGRAM ............................................................................................................................... 5

FIGURE 6: ANNUAL LEAD CONCENTRATIONS IN BOREHOLES SAMPLED ................................................... 6

FIGURE 7: ANNUAL ZINC CONCENTRATIONS IN BOREHOLES SAMPLED .................................................... 7

FIGURE 8: ANNUAL ALUMINIUM CONCENTRATIONS IN BOREHOLES SAMPLED (LOG SCALE) ................ 7

FIGURE 9: ANNUAL IRON CONCENTRATIONS IN BOREHOLES SAMPLED (LOG. SCALE) .......................... 8

FIGURE 10: ANNUAL MANGANESE CONCENTRATIONS IN BOREHOLES SAMPLED (LOG SCALE) ............. 8

FIGURE 11: ANNUAL URANIUM CONCENTRATIONS IN BOREHOLES SAMPLED (LOG SCALE) .................... 9

FIGURE 12: ANNUAL VANADIUM CONCENTRATIONS IN BOREHOLES SAMPLED ......................................... 9

FIGURE 13: ANNUAL BOX PLOT OF MAJOR IONS ANALYSED 2012-2013 ..................................................... 14

FIGURE 14: ANNUAL BOX PLOT OF TOTAL METALS ANALYSED 2012-2013 ................................................. 15

LIST OF TABLES

TABLE 1: MONITORING BOREHOLE CO-ORDINATES (UTM WGS84 Z33S) AND DETAILS .............................. 1

TABLE 2: CONCENTRATIONS OF MAJOR IONS AND PHYSICAL PARAMETERS : 2012-2013 SAMPLING .... 10

TABLE 3: CONCENTRATIONS OF TOTAL METALS : 2012-2013 SAMPLING .................................................... 12


SLR Ref. 733.14009.00005 Report No.2013-M12


August 2013

Page ii

ACRONYMS AND ABBREVIATIONS

Below a list of acronyms and abbreviations used in this report.

Acronyms / Abbreviations

Definition

IQR Inter Quartile Range

m Metres

m btc Meters below top of casing

MRT Multi Rate Test

NAr Arandis Formation

NCh Chuos Formation

NKb Karibib Formation

NKs Kuiseb Formation

NRs Rössing Formation

PID Pump Inlet Depth

Q Quartile

RWL Rest Water Level

T Transmissivity


SLR Ref. 733..14009.00005 Report No.2013-M12

2012-2013 : Sampling of Monitoring Boreholes at EPL-2902 Annual Report

August 2013

Page 1

2013-2013 : SAMPLING OF MONITORING BOREHOLES AT EPL-2902 : ANNUAL REPORT

1 INTRODUCTION

1.1 BACKGROUND

For the establishment of a comprehensive groundwater monitoring network inter alia 8 monitoring

boreholes were sited in March 2012 by SLR staff (Reference 1.) as well as drilled, utilised for long-term

groundwater monitoring and installed with uPVC plain casing and perforated sections by W. TEUBNER

DRILLING between the 8th and the 16

th of May 2012 (Reference 2.).

1.2 OBJECTIVES OF REPORT

The report presents the evaluation of the groundwater quality over the last year of sampling in 9

monitoring boreholes sampled in September 2012, December 2012, March 2013 and June 2013.

2 MONITORING BOREHOLE LOCATIONS

The monitoring borehole locations are illustrated in Figure 1 and the co-ordinates and details given in

Table 1. NLZ-W1 to NLZ-W8 were drilled and installed in May 2012. NLZ-W9 represents an old

production borehole and was included in the sampling campaign. All monitoring boreholes were sampled

and analysed on physical parameters, major ions and metals.

TABLE 1: MONITORING BOREHOLE CO-ORDINATES (UTM WGS84 Z33S) AND DETAILS

BH ID East [m]

North [m]

Depth [m]

Change in RWL [m]

2012-2013 Formation

NLZ-W1 477051 7510948 101 3.47 NCh, NRs

NLZ-W2 476976 7510127 101 1.04 NCh

NLZ-W3 475728 7508768 101 5.10 NKb

NLZ-W4 474902 7508379 95 1.67 NKs, NKb

NLZ-W5 474853 7509103 101 -0.25 NKs, NKb

NLZ-W6 474180 7509133 101 1.12 NKs

NLZ-W7 473077 7508539 77 1.95 NKs

NLZ-W8 474255 7510870 101 1.33 NKs

NLZ-W9 475910 7509639 36 No data NAr, NKb

Water levels are not measured in NLZ-W9 as this borehole has a submersible pump installed.




August 2013

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FIGURE 1: LOCATIONS OF MONITORING BOREHOLES

3 GROUNDWATER QUALITY

All monitoring boreholes were sampled and analysed on physical parameters, major ions and total

metals.

3.1 SAMPLING PROCEDURES

When arriving at the borehole during the sampling campaign the first measurement is the rest water level

and the second the depth of the borehole.

The boreholes were purged to remove stagnant water from the borehole to ensure that the groundwater

sample subsequently collected is representative of in situ groundwater. Stagnation modifies groundwater

chemistry to the extent that samples may be totally unrepresentative of the formation water. Typically 3

or more times the volume of water in the well lining is pumped from the monitoring borehole prior to

sampling.

On-site parameters, i.e. pH, EC, Eh, DO and temperature were measured and recorded during sampling.

The data is stored in field sampling sheets as hard and soft copy.

Sample containers were provided by Analytical laboratory Services (ALS) in Windhoek. The containers

for metal analysis were acidified using nitric acid to avoid precipitation of ions. The metals were analysed

by the accredited laboratory DDScience in South Africa. Samples taken were submitted to ALS in cool




August 2013

Page 3

boxes where they were analysed for major ions and from where they were shipped to DDscience CC in

South Africa

3.2 RESULTS

Water levels at the monitoring boreholes are measured quarterly and the results are shown in Figure 2.

As can be seen from Table 1 and Figure 2, there has been a small general increase in the water levels in

most boreholes during the year, probably as a result of the recent good rainy seasons. Also clearly

shown is that all boreholes except NLZ-W3 have shallow groundwater levels of above 40 m, while the

groundwater level in NLZ-W3 is at around 90 m. However, it should be noted that NLZ-W3 borehole was

dry when drilled and has since received a very slow inflow by seepage, so it may be that over a long time

period the water level would continue to increase to a similar level to the other boreholes in the area.

FIGURE 2: TIME SERIES OF WATERLEVELS IN BOREHOLES SAMPLED

The concentrations of all parameters analysed are listed in Table 2 and Table 3, while Figure 13 and

Figure 14 represent Box Plots for major ions and total metals respectively, to illustrate graphically

concentration ranges of parameters analysed.

The ends of the whisker are set at 1.5*IQR (inter quartile range) above the third quartile (Q3) and

1.5*IQR below the first quartile (Q1). If the Minimum or Maximum values are outside this range, then they

are shown as outliers. Only the Min and Max outliers are shown. The numbers of outliers for each data

set are included in the table below the chart.

3.2.1 MAJOR IONS AND PHYSICAL PARAMETERS

The concentrations of all physical parameters and major ions are listed in Table 2.

All samples analysed have a high TOTAL DISSOLVED SOLID (TDS) concentration ranging from almost

10,000 mg/l (NLZ-W4) to almost 30,000 mg/l (NLZ-W3), so can consequently be described as very




August 2013

Page 4

saline. The limit in TDS concentration for livestock watering is 6,000 mg/l, (Reference 3.). The TDS

values at each borehole have remained fairly constant throughout the year.

FIGURE 3: ANNUAL TDS CONCENTRATIONS IN BOREHOLES SAMPLED

The time series for the TDS annual data is shown in Figure 4.

FIGURE 4: TIME SERIES TDS DATA FOR NAMIB LEAD & ZINC MINE




August 2013

Page 5

THE PIPER DIAGRAM ILLUSTRATED IN

Figure 5 shows graphically the nature of water samples from a given borehole and dictates the

relationship to other boreholes. In the Piper diagram the concentrations are expressed as meq/L.

To construct the Piper diagram, the relative abundance of cations with the %meq/L of Na++K

+, Ca

2+, and

Mg2+

is first plotted on the cation triangle. The relative abundance of Cl-, SO4

2-, and HCO3

-+CO3

2- is then

plotted on the anion triangle. The two data points on the cation and anion triangles are then combined

into the quadrilateral field that shows the overall chemical property of the water sample.




August 2013

Page 6

AS SHOWN IN

Figure 5 the groundwater samples show similar solute compositions; the groundwater can be

characterised as NaCl water with different levels of concentrations. NLZ-W3 depicts an outlier with higher

ratios of Sodium + Potassium and Chloride + Fluoride but smaller ratio in Sulphides and Calcium. NLZ-

W3 was dry shortly after drilling; as no water was struck while drilling. Slowly a water level appeared by

seepage. Evaporation effects might be responsible for the different composition compared to the other

samples.




August 2013

Page 7

FIGURE 5: PIPER DIAGRAM

3.2.2 METALS

The concentrations of all metals analysed are given in Table 3. Strontium and Boron are the prevailing

metals in all boreholes sampled.

Lead and Zinc concentrations of all boreholes sampled are illustrated in Figure 6. The highest Pb-

concentrations of 356 µg/l and 295 µg/l were found in monitoring borehole NLZ-W3, located downstream

of the shaft and the old tailings facility. The provisional guideline value for lead in drinking water is 10 µg/l

(Reference 4.), which has been exceeded at least once during this reporting period in all boreholes

except NLZ-W4 and NLZ-W9.




August 2013

Page 8

The highest Zn-concentrations of 262 µg/l and 242 µg/l were analysed in samples taken from monitoring

borehole NLZ-W3. The recommended guideline value for Zinc in drinking water is 3,000 µg/l (Reference

5.), hence all boreholes are well below this value.

Figure 8 illustrates the concentrations of selected metals. Large ranges in concentrations were analysed.

All the boreholes except NLZ-W1 and NLZ-W4 regularly exceed the recommended limit of Uranium

concentration for drinking water (30 µg/l; (Reference 6.)).

FIGURE 6: ANNUAL LEAD CONCENTRATIONS IN BOREHOLES SAMPLED

FIGURE 7: ANNUAL ZINC CONCENTRATIONS IN BOREHOLES SAMPLED




August 2013

Page 9

FIGURE 8: ANNUAL ALUMINIUM CONCENTRATIONS IN BOREHOLES SAMPLED (LOG SCALE)

FIGURE 9: ANNUAL IRON CONCENTRATIONS IN BOREHOLES SAMPLED (LOG. SCALE)




August 2013

Page 10

FIGURE 10: ANNUAL MANGANESE CONCENTRATIONS IN BOREHOLES SAMPLED (LOG SCALE)

FIGURE 11: ANNUAL URANIUM CONCENTRATIONS IN BOREHOLES SAMPLED (LOG SCALE)




August 2013

Page 11

FIGURE 12: ANNUAL VANADIUM CONCENTRATIONS IN BOREHOLES SAMPLED



2012-2013 : Sampling of Monitoring Boreholes at EPL-2902 : Annual Report August 2013

Page 12

TABLE 2: CONCENTRATIONS OF MAJOR IONS AND PHYSICAL PARAMETERS : 2012-2013 SAMPLING

September

2012

Parameterp H EC Turb. TDS

Total

Alk. as

CaCO3

Total

Hard.

as

CaCO3

Ca-

Hard.

as

CaCO3

Mg-

Hard.

as

CaCO3 Cl F SO42

Nitrate

as N

Nitrite

as N Na K Mg Ca

Stability

pH, at

25°C

Lang.

Index

Ryznar

Index

Corros.

ratio

Units mS/m NTU mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l

NLZ-W1 7.0 2440 58 15862 155 4455 3071 1384 7944 0.8 1908 2.7 0.1 3988 115 336 1230 6.3 0.7 5.7 85.2

NLZ-W2 7.2 3090 335 20719 103 5758 4185 1573 10063 1.4 2386 54 0.2 5197 149 382 1676 6.4 0.8 5.6 162.0

NLZ-W3 7.0 4280 48 27338 80 5336 4664 671 15712 1.0 1148 4.7 1.7 8181 58 163 1868 6.5 0.5 5.9 292.2

NLZ-W4 7.1 1615 0.75 9459 135 2708 2102 605 5120 0.7 825 11 <0.1 2599 59 147 842 6.5 0.6 6.0 59.9

NLZ-W5 6.7 3710 9.1 25012 275 6318 4407 1911 12534 1.1 2841 29 <0.1 6464 217 464 1765 6.0 0.7 5.2 75.1

NLZ-W6 6.7 4370 12 28770 185 8692 6123 2570 15712 0.8 2091 49 <0.1 6798 185 624 2452 6.0 0.7 5.3 131.7

NLZ-W7 6.7 3070 4.4 20002 145 6947 5164 1783 10416 0.8 1831 30 <0.1 4805 137 433 2068 6.2 0.5 5.6 114.6

NLZ-W8 6.7 3540 1.3 23639 195 5757 4085 1672 11828 1.6 2567 40 <0.1 6198 187 406 1636 6.1 0.6 5.6 99.3

NLZ-W9 6.7 3520 0.25 23038 175 5940 4177 1763 11828 1.4 2270 56 <0.1 6088 184 428 1673 6.2 0.5 5.6 108.9

December

2012

Parameterp H EC Turb. TDS

Total

Alk. as

CaCO3

Total

Hard.

as

CaCO3

Ca-

Hard.

as

CaCO3

Mg-

Hard.

as

CaCO3 Cl F SO42

Nitrate

as N

Nitrite

as N Na K Mg Ca

Stability

pH, at

25°C

Lang.

Index

Ryznar

Index

Corros.

ratio


NLZ-W1 6.4 2310 171 15480 120 4332 3026 1305 8121 0.9 1890 0.5 <0.1 3760 108 317 1212 6.5 -0.1 6.5 111.9

NLZ-W2 7.0 2930 3.3 20728 110 5525 3998 1528 10063 1.3 2306 51 0.1 5012 145 371 1601 6.4 0.6 5.8 151.0

NLZ-W3 6.9 4150 5.0 29169 75 5199 4545 655 15712 1.1 1115 7.0 <0.1 7992 55 159 1820 6.5 0.4 6.1 311.2

NLZ-W4 7.1 1538 0.30 9650 130 2512 1948 564 5120 0.7 916 11 <0.1 2412 56 137 780 6.6 0.5 6.1 62.9

NLZ-W5 6.6 3500 11 24350 285 5862 4095 1767 12181 1.2 2619 36 <0.1 6360 197 429 1640 6.0 0.6 5.3 69.9

NLZ-W6 6.6 4030 6.8 26785 190 8201 6023 2178 15006 0.8 2025 54 <0.1 6803 149 529 2412 6.0 0.6 5.4 122.6

NLZ-W7 6.7 2940 0.75 19513 145 6515 4859 1655 10416 0.8 1870 32 <0.1 5075 125 402 1946 6.2 0.5 5.7 114.8

NLZ-W8 6.6 3340 0.60 22804 195 5234 3731 1503 11652 1.7 2477 38 <0.1 6612 174 365 1494 6.2 0.4 5.7 97.6

NLZ-W9 6.6 3360 0.40 23077 180 5494 3863 1631 11652 1.4 2322 54 0.1 6622 174 396 1547 6.2 0.4 5.8 104.8




Page 13

Table 2 : (Continued) Concentrations of Major Ions and Physical Parameters : 2012-2013 Sampling

March 2013

Parameter

p H EC Turb. TDS

Total

Alk. as

CaCO3

Total

Hard.

as

CaCO3

Ca-

Hard.

as

CaCO3

Mg-

Hard.

as

CaCO3 Cl F SO42

Nitrate

as N

Nitrite

as N Na K Mg Ca

Stability

pH, at

25°C

Lang.

Index

Ryznar

Index

Corros.

ratio


NLZ-W1 6.3 2715 319 15861 85 4912 3413 1499 7817 0.9 1978 <0.5 <0.1 4035 116 364 1367 6.6 -0.3 6.8 154.1

NLZ-W2 6.9 3425 2.4 20423 100 5501 3985 1515 10075 0.9 2453 51 <0.1 5584 138 368 1596 6.4 0.5 6.0 167.8

NLZ-W3 6.7 5095 52 30606 78 5487 4812 675 16328 1.2 1292 6.2 <0.1 8539 42 164 1927 6.5 0.2 6.2 312.7

NLZ-W4 7.0 1565 0.25 10173 133 2470 1898 572 5124 0.8 908 11 <0.1 2615 58 139 760 6.6 0.4 6.2 61.5

NLZ-W5 6.7 3550 4.8 25727 290 5733 3970 1763 11986 1.2 2735 36 <0.1 6660 193 428 1590 6.0 0.7 5.3 68.2

NLZ-W6 6.6 3930 4.2 26916 220 7655 5386 2269 14070 0.7 2386 35 <0.1 6624 140 551 2157 6.0 0.6 5.3 101.6

NLZ-W7 6.9 2990 0.80 19629 145 5975 4410 1565 10075 0.8 2335 32 <0.1 4698 118 380 1766 6.2 0.7 5.5 114.9

NLZ-W8 6.9 3400 0.25 23314 190 5257 3726 1532 11291 1.7 2645 43 <0.1 6419 183 372 1492 6.2 0.7 5.5 98.4

NLZ-W9 6.8 3690 0.50 25111 280 6728 4834 1894 12680 1.4 2361 61 <0.1 6366 181 460 1936 5.9 0.9 5.0 72.7

June 2013

Parameter

p H EC Turb. TDS

Total

Alk. as

CaCO3

Total

Hard.

as

CaCO3

Ca-

Hard.

as

CaCO3

Mg-

Hard.

as

CaCO3 Cl F SO42

Nitrate

as N

Nitrite

as N Na K Mg Ca

Stability

pH, at

25°C

Lang.

Index

Ryznar

Index

Corros.

ratio


NLZ-W1 6.4 2330 201 15443 93 4393 3084 1310 7643 0.9 1918 <0.5 <0.1 4472 107 318 1235 6.6 -0.2 6.7 137.5

NLZ-W2 6.7 2830 10 18931 100 5398 3915 1482 9727 1.3 2229 38 <0.1 4943 137 360 1568 6.4 0.3 6.2 160.5

NLZ-W3 6.8 3860 16 27558 71 5484 4455 1030 14070 1.1 1255 21 0.6 7487 155 250 1784 6.5 0.3 6.3 298.1

NLZ-W4 7.0 1532 0.70 9662 131 2586 2005 581 4864 0.8 851 11 <0.1 2480 56 141 803 6.6 0.4 6.2 59.2

NLZ-W5 6.7 3440 2.5 23813 271 6044 4252 1791 12159 1.2 2648 21 <0.1 6302 205 435 1703 6.0 0.7 5.3 73.5

NLZ-W6 6.5 3730 9.0 25088 214 7890 5601 2290 13028 0.7 2036 21 <0.1 6230 144 556 2243 6.0 0.5 5.4 95.8

NLZ-W7 6.7 2920 1.3 20005 145 6756 5071 1684 10075 0.8 1890 25 <0.1 4713 127 409 2031 6.2 0.5 5.6 111.7

NLZ-W8 6.7 3330 0.85 23106 185 5270 3763 1507 11117 1.6 2128 35 <0.1 6227 176 366 1507 6.2 0.5 5.7 96.8

NLZ-W9 6.8 3350 2.3 23001 171 5573 3975 1598 11291 1.4 2381 49 0.1 5948 179 388 1592 6.2 0.6 5.6 107.7




Page 14

TABLE 3: CONCENTRATIONS OF TOTAL METALS : 2012-2013 SAMPLING

Sep-12 Al Sb As Ba B Cd Cr Cu Fe Pb Li Mn Hg Mo Ni Se Sr Ti U V Zn

Units µg/l µg/l µg/l µg/l µg/l µg/l µg/l µg/l µg/l µg/l - µg/l µg/l µg/l µg/l µg/l µg/l µg/l µg/l µg/l µg/l

NZL-W1 122 0.2 0.5 46 3270 0.3 1.2 18 4586 82 - 938 0.4 3.5 10 8.7 8867 574 21 3.7 147

NZL-W2 928 0.2 1.5 36 4100 0.8 2.7 6.5 1529 34 - 256 0.2 22 7.3 36 12891 252 200 6.4 72

NZL-W3 599 12 1.9 209 3990 1.0 2.1 16 902 353 - 187 0.4 5.1 13 16 180891 267 65 2.9 193

NZL-W4 11 0.1 0.9 63 1160 0.1 1.0 1.8 45 7.8 - 19 0.5 5.3 5.5 14 10083 0.9 36 3.2 25

NZL-W5 247 0.2 1.2 105 4290 1.2 2.1 6.3 392 98 - 283 0.2 11 17 30 22185 284 90 6.2 58

NZL-W6 247 0.4 1.4 78 3280 1.4 1.8 7.1 628 41 - 600 0.2 11 32 65 36609 236 496 2.1 68

NZL-W7 38 0.1 3.2 103 2290 0.9 0.3 4.4 66 30 - 36 0.6 6 6.2 39 24972 300 71 4.8 44

NZL-W8 21 0.1 5.8 37 5070 0.5 1.1 4.4 57 34 - 25 0.6 14 3.8 55 15507 2.7 83 16 78

NZL-W9 4 0.1 4.8 32 4660 0.2 2.4 2.3 43 0.4 - 2.6 0.7 13 4.2 51 16935 1.2 75 6.3 11

Nov-12 Al Sb As Ba B Cd Cr Cu Fe Pb Li Mn Hg Mo Ni Se Sr Ti U V Zn


NZL-W1 62 0.1 1.2 35 8580 0.1 1.5 4.2 13085 43 193 963 0.2 4.1 2.6 37 8703 4.0 5.9 1.7 55

NZL-W2 205 0.2 1.7 36 10890 0.8 1.4 3.5 416 30 201 213 0.2 22 5.5 80 13870 9.8 179 3.1 85

NZL-W3 236 9.6 10 163 7320 1.4 1.1 11 292 106 2243 143 0.3 6.6 9.1 218 177717 11 57 1.4 242

NZL-W4 108 0.1 1.0 59 2980 0.1 1.0 1.3 162 4.6 76 11 0.4 5.7 3.6 28 11193 7.0 26 3.8 18

NZL-W5 235 0.2 2.4 64 11650 1.7 1.0 4.1 279 48 477 91 0.2 11 10 98 21659 16 73 8.5 43

NZL-W6 183 0.4 7.5 60 8920 0.7 2.6 3.9 424 25 237 453 0.1 8.3 23 186 35407 7.6 714 2.5 49

NZL-W7 18 0.2 2.9 87 6830 0.7 0.5 2.1 52 20 162 66 0.4 6.2 3.4 75 26580 1.0 59 3.6 38

NZL-W8 19 0.1 5.1 31 12350 0.2 0.8 2.9 64 10 245 7.2 0.4 14 1.9 57 15709 1.3 74 16 22

NZL-W9 14 0.1 4.2 26 11040 0.2 4.3 1.0 178 2.6 209 8.9 0.3 11 8.2 88 14379 1.3 82 5.8 9.6




Page 15

Table 3 : (Continued) Concentrations of Total Metals : 2012-2013 Sampling

Mar-13 Al Sb As Ba B Cd Cr Cu Fe Pb Li Mn Hg Mo Ni Se Sr Ti U V Zn


NZL-W1 57 0.1 0.4 35 2550 0.1 0.7 8.7 27292 21 218 815 1.3 3.5 1.0 3.1 8773 3.3 3.2 2.4 23

NZL-W2 125 0.3 2.1 32 2820 1.0 0.8 5.9 254 32 184 127 1.2 21 4.2 53 12673 5.2 217.3 3.3 110

NZL-W3 1037 6.9 2.1 144 3210 1.6 2.6 12 1150 295 2285 127 1.7 4.5 9.3 52 170174 53 73 3.5 262

NZL-W4 9.0 0.2 0.5 61 510 0.1 0.2 1.5 23 3.4 73 1.5 1.9 4.5 2.0 12 9194 0.5 25 2.3 12

NZL-W5 200 0.3 1.8 74 3710 1.8 0.7 8.2 303 42 442 62 2.1 13 8.9 39 21913 15 88 9.0 47

NZL-W6 108 0.4 0.6 52 2960 0.5 0.8 8.6 255 13 247 405 0.6 5.8 13 41 37201 5.7 791 2.2 41

NZL-W7 54 0.2 1.3 92 2280 0.6 0.2 5.8 155 26 143 24 1.6 4.9 3.2 30 22664 3.5 57 4.0 53

NZL-W8 8.5 0.2 5.1 36 3500 0.3 0.8 4.1 22 7.0 213 17 1.6 11 2.6 59 11550 0.4 112 16 28

NZL-W9 12 0.2 3.6 33 3820 0.2 2.7 1.0 116 2.7 213 3.7 1.5 8.7 4.1 43 13651 0.9 97 6.3 12

Jun-13 Al Sb As Ba B Cd Cr Cu Fe Pb Li Mn Hg Mo Ni Se Sr Ti U V Zn


NZL-W1 70 0.2 2.6 35 2630 0.2 0.5 6.1 28357 37 167 962 1.4 1.9 1.5 61.2 8166 5.3 3.8 1.2 44

NZL-W2 236 0.2 1.5 41 3510 1.1 0.7 7.3 363 54 157 206 1.7 18 5.7 69 11944 12 200 2.3 160

NZL-W3 228 4.4 4.7 170 1460 1.6 1.1 5.7 397 136 1108 160 4.4 6.8 5.1 140 97008 13 70 1.2 148

NZL-W4 13 0.1 0.8 60 600 0.1 0.1 2.2 31 2.3 58 1.3 2.9 4.9 2.2 30 10325 1.4 29 2.8 16

NZL-W5 114 0.2 2.2 55 2490 2.2 0.4 10.6 86 22 363 40 2.9 11 8.1 84 19272 5.7 76 8.0 48

NZL-W6 126 0.3 2.5 47 1830 0.6 0.4 8.9 517 12 173 432 2.4 4.6 11 112 32272 4.8 597 1.3 40

NZL-W7 62 0.1 8.1 94 1400 0.5 0.3 10.7 56 7.1 125 24 2.0 4.9 1.4 170 23183 1.6 51 3.8 30

NZL-W8 56 0.1 4.6 35 3180 0.2 0.4 4.9 38 5.0 189 5 2.2 13 1.5 103 13690 1.3 86 17 24

NZL-W9 77 0.1 3.5 30 3310 0.6 3.1 2.2 273 7.1 170 16 1.9 11 3.2 83 14380 1.3 97 4.7 92




Page 16

Labels p H EC Turb. TDS

Total Alk. as

CaCO3

Total Hard.

as CaCO3

Ca-Hard. as

CaCO3

Mg-Hard. as

CaCO3 Cl F SO42 Nitrate as N Nitrite as N K Mg Ca

Stability pH,

at 25°C Lang. Index Ryznar Index Corros. ratio

Min 6 1532 0 9459 71 2470 1898 564 4864 1 825 1 2412 42 137 760 6 0 5 59

Q1 6.675 2897.5 0.75 19367.3847 108.25 5225.25 3729.631 1308.393 9979 0.8 1860.25 13.5 4709.25 113.25 317.75 1493.5 6.075 0.40100273 5.46087361 82.675

Median 6.7 3355 3.75 23019.7151 145 5512.818 4090 1548.368 11291 1.05 2109.5 33.5 6143 142 376 1638 6.20190888 0.52135709 5.69366812 108.305487

Q3 6.9 3695 11.25 25093.7691 191.25 6112.29075 4700.92975 1764 12570.5 1.325 2386 47.5 6614.5 179.5 428.25 1882.75 6.5 0.64214015 6.1 140.862914

Max 7 5095 335 30606 290 8692 6123 2570 16328 2 2841 61 8539 217 624 2452 7 1 7 313

IQR 0.225 797.5 10.5 5726.38431 83 887.04075 971.29875 455.607 2591.5 0.525 525.75 34 1905.25 66.25 110.5 389.25 0.425 0.24113742 0.63912639 58.1879143

Upper Outliers 0 1 7 0 0 4 0 1 0 0 0 0 0 0 1 0 0 0 0 4

Lower Outliers 1 4 0 4 0 4 4 4 4 0 4 0 0 0 4 4 0 3 0 0

0.01

0.1

1

10

100

1000

10000

100000

p H EC Turb. TDS Total Alk.as CaCO3

TotalHard. as

CaCO3

Ca-Hard.as CaCO3

Mg-Hard.as CaCO3

Cl F SO42 Nitrate asN

Nitrite asN

K Mg Ca StabilitypH, at

25°C

Lang.Index

RyznarIndex

Corros.ratio

Min Outlier Max Outlier

FIGURE 13: ANNUAL BOX PLOT OF MAJOR IONS ANALYSED 2012-2013




Page 17

Labels Aluminium Antimony Arsenic Barium Boron Cadmium Chromium Copper Iron Lead Lithium Manganese Mercury Molybdenum Nickel Selenium Strontium Titanium Uranium Vanadium Zinc

Min 4 0 0 26 510 0 0 1 22 0 58 1 0 2 1 3 8166 0 3 1 10

Q1 20.50 0.13 1.25 35.27 2 535.00 0.22 0.48 2.75 62.25 7.10 164.70 16.28 0.36 4.94 3.06 34.50 11 845.31 1.31 55.43 2.37 24.72

Median 92.24 0.18 2.19 53.10 3 295.00 0.57 0.98 5.34 263.85 25.31 201.00 78.50 0.67 7.57 5.32 54.01 15 608.00 5.24 74.50 3.65 45.36

Q3 210.72 0.26 4.29 80.25 4 762.50 1.04 1.88 8.30 447.37 42.00 245.82 262.75 1.77 11.42 9.16 83.45 25 374.00 13.65 101.00 6.31 79.75

Max 1 036.71 12.00 10.00 209.00 12 350.00 2.23 4.30 18.00 28 357.21 353.00 2 284.76 963.00 4.36 22.00 32.00 218.00 180 891.00 574.00 791.21 16.67 261.55

IQR 190.22 0.13 3.04 44.98 2 227.50 0.82 1.39 5.55 385.12 34.90 81.12 246.47 1.41 6.49 6.10 48.95 13 528.69 12.34 45.58 3.94 55.03

Upper Outliers 3 4 1 3 6 0 1 1 6 5 5 4 1 3 2 3 4 7 8 4 3

Lower Outliers 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

0.01

0.10

1.00

10.00

100.00

1 000.00

10 000.00

100 000.00

1 000 000.00

Aluminium Antimony Arsenic Barium Boron Cadmium Chromium Copper Iron Lead Lithium Manganese Mercury Molybdenum Nickel Selenium Strontium Titanium Uranium Vanadium Zinc

Min Outlier Max Outlier

FIGURE 14: ANNUAL BOX PLOT OF TOTAL METALS ANALYSED 2012-2013




August 2013

Page 18

4 SUMMARY AND CONCLUSIONS

Nine (9) monitoring boreholes were sampled and analysed on physical parameters, major ions

and total metals.

Groundwater in the project area is saline and unsuitable for human consumption with TDS

concentrations ranging between 9,459 mg/l (NLZ-W4) to 30,606 mg/l (NLZ-W3).

Large ranges in metal concentrations were detected.

All the boreholes except NLZ-W4 and NLZ-W9 have exceeded the recommended guideline

value for drinking water for lead of 10 µg/l at least once during this reporting period.

All the boreholes except NLZ-W1 and NLZ-W4 have consistently exceeded the recommended

limit of Uranium concentration for drinking water of 30 µg/l during this reporting period.

5 REFERENCES

Reference 1. SLR (2012A): Siting of 8 monitoring wells at EPL-2902. General settings, siting

report and drilling specifications. Report No.: 2012-G12-V1.

Reference 2. SLR (2012B): Drilling and installation of 8 monitoring wells at EPL-2902. Drilling

results and well characteristics. Report No.: 2012-G19-1V.

Reference 3. The Water Act (Act 54 of 1956), Department of Water Affairs, Ministry of

Agriculture, Water and Rural Development, Government of the Republic of

Namibia.

Reference 4. WHO (2003): Zinc in drinking water. Background document for development of

WHO guidelines for drinking water quality. WHO/SDE/WSH/03.04/17.

Reference 5. WHO (2011A): Lead in drinking water. Background document for development of

WHO guidelines for drinking water quality. WHO/SDE/WSH/03.04/09/Rev/1

Reference 6. WHO (2011B): Uranium in drinking water. Background document for

development of WHO guidelines for drinking water quality.

WHO/SDE/WSH/03.04/118/Rev/1

2012/08/22

Jonathan Church

(Project Manager)

Arnold Bittner

(Project Reviewer)




August 2013

Page 19

RECORD OF REPORT DISTRIBUTION

SLR Reference: 733.14012.00001

Title: 2012 – 2013 Sampling of Monitoring Boreholes at EPL 2902 : Annual Report

Report Number: 2012-M12

Proponent: Namib Lead and Zinc (Pty) Ltd.

Name Entity Copy No. Date issued Issuer

COPYRIGHT

Copyright for these technical reports vests with SLR Consulting unless otherwise agreed to in

writing. The reports may not be copied or transmitted in any form whatsoever to any person

without the written permission of the Copyright Holder. This does not preclude the authorities’

use of the report for consultation purposes or the applicant’s use of the report for project-

related purposes.

namib lead and zinc mine 2012-2013 annual report sampling ... · slr ref. 733.14009.00005 report...

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