Appendix F: Surface and Groundwater Monitoring Report · and anions as well as physical parameters;...

ZITHOLELE CONSULTING

Appendix F: Surface and Groundwater Monitoring Report

Surface and Groundwater Quarterly Monitoring Report October 2016

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Registration No. 2015/025310/07 Vat Number: 4800273320

P.O. Box 18720, Pretoria North, 0116

Tel: (+27) 76 322 6664 Fax: (+27) 86 566 1051

www.lefatsheminerals.co.za

ESKOM

Duvha Power Station:

Surface and Ground- water

Quarterly Monitoring Report

(October 2016)


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Duvha Power Station

Surface and Ground- water Quarterly Monitoring

Report

DOCUMENT ISSUE STATUS

Report Issue Final Report

Our Reference Number LMC/EDPS/001/16

CLIENT CONSULTANT

Name of Company

Eskom – Duvha Power Station

Lefatshe Minerals and Consulting

(Pty) Ltd

Contact Person

Me. Morongwa Molewa

Section Chemist

Mr. Reuben Mampuru

Consultant

(Pr.Sci.Nat)

Postal Address Old Bethal Road, Emalahleni, 1034 P.O. Box 18720, Pretoria North, 0116

Tel Tel: +27 13 690 0111 Tel: +27 76 322 6664

Fax Fax: +27 13 690-0448 Fax: +27 86 566 1051

Website www.eskom.co.za www.lefatsheminerals.co.za

COPYRIGHT WARNING

This report has been prepared by LMC (on behalf of Eskom Duvha Power Station) with all reasonable skill, care

and diligence within the terms of the contract with the client, and taking into account the resources devoted to it by

agreement with the client. We disclaim any responsibility to the client and any other in respect to any matters

outside the scope of the project.

This report is confidential to the client and we accept no responsibility of whatsoever nature to third parties to

whom this report, or any part thereof, is made known. Any such parties rely on the report at their own risk.

http://www.lefatsheminerals.co.za/


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TABLE OF CONTENTS

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

1.1 Project Background ................................................................................... 1

2. SITE DESCRIPTION ........................................................................... 1

3. MONITORING PROGRAMME............................................................. 2

3.1 Surface water monitoring .......................................................................... 3

3.1.1 Surface water laboratory results .......................................................................... 5

3.1.1.1 Surface water chemistry data presentation ......................................................................... 5

3.1.1.2 Ash Water Return Dam (AP09 – Low level & PP04 – High level): ........................................... 5

3.1.1.3 Mike Fell Pond or Emergency Pond (PP03): ......................................................................... 6

3.1.1.4 Witbank Dam (PP08) ........................................................................................................... 7

3.1.1.5 Final Effluent Pond (PE01) ................................................................................................... 7

4. GROUNDWATER MONITORING ........................................................ 8

4.1 Groundwater Levels ................................................................................. 11

4.2 Groundwater Laboratory Results ............................................................ 14

4.2.1 Groundwater Chemistry Data Presentation ....................................................... 14

5. CONCLUSION:.................................................................................. 23


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LIST OF TABLES

TABLE 1: SURFACE WATER SAMPLING LOCATIONS (DUVHA–WUL) ................................................ 3

TABLE 2: ASH RETURN WATER QUALITY RESULTS (COMPARED TO WUL) ....................................... 6

TABLE 3: EMERGENCY POND QUALITY RESULTS (COMPARED TO THE WUL) ................................... 6

TABLE 4: WITBANK DAM QUALITY RESULTS (COMPARED TO WUL) ................................................. 7

TABLE 5: FINAL SEWAGE EFFLUENT QUALITY RESULTS ................................................................ 8

TABLE 6: GROUNDWATER SAMPLING LOCATIONS (DUVHA–WUL) .................................................. 9

TABLE 7: GROUNDWATER LEVELS OF THE DPS BOREHOLES (IN WUL) ........................................ 11

TABLE 8: GROUNDWATER QUALITY RESULTS FOR POWER STATION BOREHOLES AS COMPARED TO

GROUNDWATER RESERVE QUALITY SET IN DPS WUL......................................................... 14

TABLE 9: GROUNDWATER QUALITY RESULTS OF THE POWER STATION BOREHOLES AS COMPARED TO

WUL ............................................................................................................................ 15

TABLE 10: GROUNDWATER QUALITY RESULTS OF ASH DAM AS COMPARED TO GROUNDWATER

RESERVE QUALITY SET IN DPS WUL ................................................................................ 17

TABLE 11: GROUNDWATER QUALITY RESULTS OF THE ASH DAM BOREHOLES AS COMPARED TO WUL

LIMITS ........................................................................................................................... 17

TABLE 12: GROUNDWATER QUALITY RESULTS OF COAL STOCKYARD BOREHOLES AS COMPARED TO

THE GROUNDWATER RESERVE QUALITY SET IN DPD WUL .................................................. 19

TABLE 13: GROUNDWATER QUALITY RESULTS OF THE COAL STOCKYARD BOREHOLES AS COMPARED

TO THE WUL LIMITS ....................................................................................................... 19

TABLE 14: GROUNDWATER QUALITY RESULTS OF SEWAGE PLANT BOREHOLES AS COMPARED TO THE

GROUNDWATER RESERVE QUALITY SET IN DPS WUL......................................................... 21

TABLE 15: GROUNDWATER QUALITY RESULTS OF THE SEWAGE PLANT BOREHOLES AS COMPARED TO

THE WUL LIMITS ............................................................................................................ 21

LIST OF FIGURES

FIGURE 1: LOCALITY MAP INDICATING DUVHA POWER STATION ..................................................... 2

FIGURE 2: LOCATION OF THE SURFACE WATER SAMPLING POINTS (DUVHA–WUL) .......................... 4


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FIGURE 3: GROUNDWATER SAMPLING LOCATIONS (DUVHA – WUL) ............................................. 10

FIGURE 4: GROUNDWATER LEVEL TRENDS FOR DPS BOREHOLES (WUL) .................................... 12

FIGURE 5: CORRELATION BETWEEN GROUNDWATER LEVELS AND TOPOGRAPHY............................ 13

FIGURE 6: GROUNDWATER LEVEL CONTOUR MAP (FOR WUL BHS) ............................................. 13

FIGURE 7: GROUNDWATER QUALITY TRENDS OF THE POWER STATION BOREHOLES ....................... 16

FIGURE 8: GROUNDWATER QUALITY TRENDS OF THE ASH DAM BOREHOLES .................................. 18

FIGURE 9 : GROUNDWATER QUALITY TRENDS OF THE COAL STOCKYARD BOREHOLES .................... 20

FIGURE 10: GROUNDWATER QUALITY TRENDS OF THE SEWAGE PLANT BOREHOLES ....................... 22


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1. INTRODUCTION

Lefatshe Minerals and Consulting (Pty) Ltd (LMC) was commissioned by Eskom’s Duvha Power

Station to update their existing water quality database and to compile a quarterly monitoring

report for submission to the Department of Water and Sanitation (DWS). The reports provides

quarterly overview of the status of the surface and groundwater quality.

The scope of work included the following:

Updating surface and groundwater quality database;

Evaluation and assessment of water quality monitoring data;

Predict environmental impacts;

Perform a risk assessment of the areas with high levels of contamination; and

Preparation of a quarterly water monitoring report.

1.1 Project Background

The following information was available and where applicable are referred to:

Groundwater sampling guidelines (second edition); John M.C. Weaver (2007)

Department of Water Affairs and Forestry, 2006. Best Practice Guideline G3: Water

Monitoring Systems;

Surface and groundwater quality guidelines set out in the Duvha Power Station’s

Water Use Licence; Department of Water and Sanitation.

Duvha Power Station surface and groundwater quality monitoring report (with the

most recent report relating to monitoring conducted in June 2016).

2. SITE DESCRIPTION

Duvha Power Station (DPS) is located ±15 km south-east of Emalahleni (Witbank) on the

R544 Road to Bethal (Figure 1). The power station was constructed in 1975 and was since in

operation. The power station uses coal to generate electricity.


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Figure 1: Locality map indicating Duvha Power Station

3. MONITORING PROGRAMME

Quarterly surface and groundwater quality monitoring has been carried out at the Power

Station since June 2006. The sample are collected on different locations/ sites around the

Power Station. These sites are divided into five regions of possible impact (as set out by GHT

in their previous monitoring); namely:

o Power Station Area;

o The Coal Stock Yard Area;

o The Ashing Area;

o The Sewage Plant;

o Non perennial streams around the power station.

The samples (surface and groundwater) are collected every quarter and sent to an

accredited laboratory for chemical and microbiological analysis. The samples are taken

(purged and/ or bailed), transported and stored in accordance with the sampling protocol

established by the Water Research Commission (Weaver et al., 2007) and submitted to an

accredited laboratory, in this case Inspectorate UIS Laboratory in Gauteng, for analysis. The

results of the analysis are forwarded to LMC for analysis, storage and inclusion in the

quarterly monitoring report. The results are compared to DPS’s WUL requirements.



3.1 Surface water monitoring

The report covers the sampling which was conducted during October 2016. Surface samples

were collected from different locations around the power station as specified in the WUL

(Figure 2). Table 1 provide the details of the surface monitoring points.

Due to an ongoing drought some of the streams around the power station are currently dry

and therefore no samples were collected.

Table 1: Surface water sampling locations (Duvha–WUL)

Sampling Points

Location Coordinates

Sampled Current State Latitude Longitude

AP08 Witbank Dam 25.92933 29.30551 Y Satisfactory

AP09 Ash Water Return Dam (Low Level) 25.92522 29.34438 Y Satisfactory

PE01 Final effluent (Sewage Treatment Plant) 25.95852 29.32326 Y (C & B) Satisfactory

PP03 Emergency pan 25.96109 29.34756 Y Satisfactory

PP04 Ash water return dams (High Level) 25.95452 29.34423 Y Satisfactory

PP20 Driefontein Dam 25.98749 29.33147 N -



Figure 2: Location of the surface water sampling points (Duvha–WUL)



3.1.1 Surface water laboratory results

This section contains the results of surface water chemistry of the samples obtained from

different locations around the power station. The sample analysis included all major cations

and anions as well as physical parameters; Electrical Conductivity (EC), pH, Total Dissolved

Solids (TDS), Sulphate (S04) and Iron (Fe). The results cover the sampling conducted during

October 2016 monitoring.

The results of all the inorganic chemical and bacteriological analyses that have been

performed on water samples from Duvha Power Station during the current monitoring

program are available in an electronic database for review. The certificates are provided in

refer to Appendix C.

3.1.1.1 Surface water chemistry data presentation

In this section the water quality results are presented in a table format and classified

according to the “Water Use License limits set by DWS for Duvha Power Station site’.

Where parameters exceed Duvha’s WUL limits the values are colour coded (refer to Table 2,

Table 3, Table 4and Table 5).

3.1.1.2 Ash Water Return Dam (AP09 – Low level & PP04 – High level):

The Ash Return Water (AWR) at the power station is also monitored on a monthly basis.

However, no results of the AWR were reported at the time of the compilation of this report.

The results of this monitoring are indicative of the quality of water that is being used for the

ashing processes. The concentrations of parameters monitored as per the WUL requirements

are indicated Table 2.

The results indicate alkaline pH concentrations for Ash water samples. The alkalinity of the

water is attributed to the ashing process in a coal-fired power station. The results also indicate

slightly elevated sodium concentrations when compared to the WUL limits.



Table 2: Ash Return Water quality results (compared to WUL)

Parameters WUL Waste effluent

disposal limit PP04 AP09

pH 4.5-9.5 11.5 11.3

EC mS/m 2578 218 186

TDS mg/l 1225 1320 1210

Ca mg/l 930 250 212

Mg mg/l 1213 0.12 0.12

Na mg/l 127 131 131

K mg/l 65 31.2 33.1

Cl mg/l 150 91 92.7

SO4 mg/l 2359 623 642

NO3-N mg/l 15 1.24 0.549

F mg/l 1.5 0.767 0.71

Fe (mg/l) 2 <0.05 <0.05

Mn (mg/l) 2 <0.05 <0.05

Al (mg/l) 2 0.22 <0.05

Total Alkalinity as

CaCO3 (mg/l) 200 270

Total Hardness as CaCO3 (mg/l)

1225 422

3.1.1.3 Mike Fell Pond or Emergency Pond (PP03):

Mike Fell Pond is a water resource that is situated next to the Duvha Power Station. The pond

was used by the station in emergency situations where the station was unable to control the

available capacity of water in their process from 1983 to 2013. The station monitors the water

quality of the pond on a monthly basis.

The emergency pond quality results (as indicated in Table 3) indicates various non-

compliances when compared to the WUL during the current monitoring phase. The elevated

parameters (EC, Ca, Na, Cl and S04) might be attributed to other external effluence other

than the power station based on the location of the pond.

Table 3: Emergency Pond quality results (compared to the WUL)

Parameters WUL limits PP03

pH 5.0-9.5 7.01

EC mS/m 70 157

Ca mg/l 80 164

Mg mg/l 70 3.17



Na mg/l 100 168

Cl mg/l 100 117

SO4 mg/l 200 589

N as N03 6 0.587

3.1.1.4 Witbank Dam (PP08)

A sample was collected at the Witbank Dam located downstream of the power station to the

northwest and submitted to the laboratory for analysis (figure). The results of the analysis are

provided in Table 4.

The results indicate elevated magnesium and sulphate concentrations during the current

monitoring period. The possible pollution source might from other activities occurring between

the power station and the dam (e.g. mining and other industries).

Table 4: Witbank dam quality results (compared to WUL)

Parameters WUL limits AP08

pH 5.0-9.5 7.67

EC mS/m 70 65.4

Ca mg/l 80 64.8

Mg mg/l 70 489

Na mg/l 100 35.8

Cl mg/l 100 20

SO4 mg/l 200 282

N as N03 6 0.133

3.1.1.5 Final Effluent Pond (PE01)

During normal operations the final sewage effluent, which is treated, is pumped from the

sewage works into the station’s Ash Dams. The effluent disposed is sampled on a weekly

basis and compliance with the Water Use License requirements is determined.

The current practice has been to keep the final effluent in the maturation pond and not

release any effluent into the Ash Dams. This practice was initiated due to the maintenance



that was taking place at the plant. The last release of sewage effluent took place was in

January this year, therefore no effluent was discharged for this reporting period. The sampling

and monitoring of the final effluent dam took place for information purposes only.

The effluent qualities shows two parameters (ammonia and suspended solids) which fall

above WUL limits during the current monitoring period (Table 5). The results also indicate

faecal coliforms are almost above WUL limits. Water levels are closely monitored to ensure

that no overflows take place from any of the ponds at the Sewage Treatments Plant.

Table 5: Final Sewage Effluent quality results

Parameters WUL - Sewage Treatment

PE01

Faecal Coliforms 1000 1000

pH 5.5-9.5 8.71

Electrical Conductivity (EC mS/m)

70-150 38.3

Chemical Oxygen Demand (COD mg/l)

75 64

Chlorine as free chlorine (mg/l) 0.25 No value reported

Ammonia as Nitrogen (mg/l) 3 6.43

Nitrate/ Nitrite as Nitrogen (mg/l)

15 0.24

Suspended Solids (mg/l) 25 30

Ortho-phosphate as phosphorus (mg/l) 10 5.38

Fluorite as F (mg/l) 1 0.397

4. GROUNDWATER MONITORING

LMC collected groundwater samples at the locations listed in Table 6 and submit them to an

independent accredited laboratory, in this case UIS laboratory, for chemical analysis. Figure 3

indicate the positions of the groundwater sampling points at Duvha Power Station (as listed in

the WUL).

The groundwater samples can be divided into four regions of possible impacts:

Power Station Area

Ash Dam Area

Coal Stock Yard Area

Sewage Plant Area



Table 6: Groundwater sampling locations (Duvha–WUL)

Sampling Points

Location/ Description

Coordinates (WGS 84) Sampled Current State

Latitude Longitude

PB09 Borehole upstream from the upper Ash Return Water

Dam 25.95560 29.34395 Y Satisfactory

PB10 Borehole downstream from the upper Return Water

Dam 25.95373 29.34246 Y Satisfactory

PB11 Supply borehole on Mr Gouws farm 25.95830 29.34879 N No access

PB12 (B) Borehole at Sewage Plant West 25.96053 29.32237 Y (C &

B) Satisfactory

PB13 (B) Borehole at Sewage Plant West 25.95956 29.32235 Y (C &

B) Satisfactory

PB18(B) North of Sewage Plant 25.95843 29.32299 Y (C &

B) Poor no cap & pole

CB06 Borehole outside power station area East of coal

stockyard 25.95814 29.34707 Y Satisfactory


stockyard 25.96070 29.34594 Y Satisfactory


stockyard 25.96413 29.34538 N Blocked

AB01 Borehole near old farmhouse 25.93416 29.32599 Y Satisfactory

AB02 Borehole near AB01 towards Witbank Dam 25.93181 29.32606 Y Satisfactory

AB03 Borehole near AB01 and AB02 25.93187 29.32738 Y Satisfactory

AB04 Borehole at pump station of Ash Dam 25.92497 29.34515 Y Poor condition, no

pole

AB05 Borehole north of ash dam near ash return water

dam 25.93106 29.34893 Y Satisfactory



Figure 3: Groundwater sampling locations (Duvha – WUL)



4.1 Groundwater Levels

Groundwater level monitoring is essential for the determination of groundwater flow direction.

It is also important as input for the development of hydrogeological models and conclusions

regarding site hydrogeology.

Table 7 Indicate groundwater levels of WUL boreholes at Duvha Power Station. The

groundwater level trends are indicated on Figure 4.There was no groundwater level data

reported for January to June 2016 and therefore, groundwater levels where only compared to

2015 data.

There are few gaps in groundwater levels of the boreholes at DPS. Some of the water levels

were not reported and therefore where not included in the current report.

All borehole indicate a drop in groundwater levels during January to December 2016. A drop

in groundwater level can be attributed to the drought which was experienced during 2016.

The boreholes indicate a drop of water levels of between 0.5m to 2m when compared to 2015

results.

Table 7: Groundwater levels of the DPS boreholes (in WUL)

Location Borehole Number

Jan-15 Jun-15 Sep-15 Mar-16 Jun-16 Sep-16

Power Station PB09 4.39 - - - - 5.63

PB10 2.98 - - - - 5.80

Ash Dam

AB01 3.25 4.00 1.65 - - 4.05

AB02 1.74 1.90 1.05 - - 2.00

AB03 0.94 1.75 - - 1.18

AB04 1.63 1.54 1.68 - - 2.00

AB05 1.44 1.52 1.49 - - 1.65

Sewage Plant

PB12 1.14 1.23 1.93 - - 1.50

PB13 1.42 - 1.34 - - 2.03

PB18 1.21 - - - - 1.33

Coal Stockyard

CB06 3.66 - - - - 4.36

CB07 3.23 - - - - 3.64



Figure 4: Groundwater level trends for DPS boreholes (WUL)

Selected boreholes have been used to evaluate the correlation between groundwater level

elevations and topographic elevations (Figure 5). The topography and groundwater elevation

show a high degree of correlation (99.67%). This indicates that groundwater follows the

topography and the aquifers are unconfined to semi-confined.

Bayesian interpolation was subsequently employed to generate groundwater level elevations

for the rest of the study area. The interpolation of the data gives a reliable indication of the

regional groundwater flow directions.

The groundwater levels around the power station vary between 1531 and 1606 mamsl with

the direction of groundwater generally flow to the northerly direction (Figure 6). Groundwater

level monitoring is essential for the determination of groundwater flow directions and to

establish whether abstraction is sustainable. It is also important as input for the development

of hydrogeological models and conclusions regarding site hydrogeology.



Figure 5: Correlation between groundwater levels and topography

Figure 6: Groundwater level contour map (for WUL BHs)



4.2 Groundwater Laboratory Results

4.2.1 Groundwater Chemistry Data Presentation

In this section, the results returned for groundwater samples are reported in table format

where they are compared against the Duvha Power Station’s Water Use License (WUL).

Where the parameter concentration exceeds the limits the values are highlighted in either

yellow (refer to Table 9, Table 10, Table 11, Table 13, Table 15 Table 13 Table 14 and Table

15).

The results of the laboratory analysis indicate the following:

Power Station Area:

Table 8 and Table 9 Indicate groundwater quality results of the power station boreholes.

Borehole PB11 located at Mr Gouws’s farm could not be accessed and therefore no sampling

was conducted on this borehole.

The results of the groundwater samples collected from the boreholes at the power station

area indicate parameters which fall well within the WUL limits. The results indicate no impact

from the power station.

The long term pH trends indicate neutral pH throughout 2015-2016 monitoring periods (Figure

7). The long term calcium, sodium and sulphate trends indicate parameters which fall well

within WUL limits throughout 2015-2016 monitoring periods.

Table 8: Groundwater quality results for power station boreholes as compared to

groundwater reserve quality set in DPS WUL

Locations

Parameters pH TDS

mg/l Ca mg/l Mg mg/l Na mg/l K mg/l Cl mg/l

SO4

mg/l

Groundwater reserve quality

5-9.5 462 45 24 36 6.5 23 152

Power Station Area

PB09 6.41 100 1.48 0.66 30.8 0.64 10.8 11.3

PB10 6.64 68 10.5 4.13 4.93 2.05 3.4 4



Table 9: Groundwater quality results of the power station boreholes as compared to

WUL

July-Sept 2017

pH EC

mS/m TDS mg/l

Ca mg/l

Mg mg/l

Na mg/l

K mg/l Cl

mg/l SO4 mg/l

NO3-N mg/l

F mg/l Fe

(mg/l) Mn

(mg/l)

WUL WQOs 5-9.5 2578 1225 930 1213 127 65 150 2359 15 1.5 2 2

PB09 6.41 13.1 100 1.48 0.66 30.8 0.64 10.8 11.3 <0.13 <0.042 0.77 0.23

PB10 6.64 10.6 68 10.5 4.13 4.93 2.05 3.4 4 <0.13 0.145 0.28 0.23



Figure 7: Groundwater quality trends of the power station boreholes



Ash Dam Area:

The majority of the boreholes in the vicinity of the ash dam (located to downstream of the

dam) indicate elevated sodium (Na) and chloride (Cl) concentrations when compared to the

groundwater quality reserve set in the WUL (Table 10). When comparing the Cl and Na found

in these boreholes to those found at the toe drain, it is evident that the source of the Chlorides

in the boreholes is from Ash Water. Cl and Na are major component of ash and are both

easily leached out. The borehole will be closely monitored and if contamination persists,

measures to prevent further contamination will be investigated. Borehole AB02 indicates

parameters which are within the groundwater quality reserve limits.

When compared to the WUL limits the results indicate parameters which fall well within limits

for all boreholes (Table 11).

Table 10: Groundwater quality results of ash dam as compared to groundwater reserve

quality set in DPS WUL

Locations

Parameters pH TDS mg/l

Ca mg/l

Mg mg/l

Na mg/l

K mg/l Cl

mg/l SO4 mg/l


5-9.5 462 45 24 36 6.5 23 152

Ashing Dam Area

AB01 6.8 162 8.32 5.16 46.3 4.08 25.4 12.4

AB02 7.06 182 23.2 4.5 32.3 1.32 2.49 4.68

AB03 6.83 262 6.42 7.15 97.9 2.19 132 4.07

AB04 6.66 465 45.9 32.7 77.8 3.38 75.2 184

AB05 6.8 163 11.6 4.43 36.3 3.27 16.7 3.89

Table 11: Groundwater quality results of the ash dam boreholes as compared to WUL

limits

Locations

Parameters pH EC

mS/m TDS mg/l

Ca mg/l

Mg mg/l

Na mg/l

K mg/l

Cl mg/l

SO4 mg/l

NO3-N mg/l

F mg/l

Fe

(mg/l)

WUL WQOs

5-9.5 2578 1225 930 1213 127 65 150 2359 15 1.5 2

Ash Dam Area

AB01 6.8 25.2 162 8.32 5.16 46.3 4.08 25.4 12.4 <0.13 0.474 <0.05

AB02 7.06 23.8 182 23.2 4.5 32.3 1.32 2.49 4.68 <0.13 1.92 0.13

AB03 6.83 48.6 262 6.42 7.15 97.9 2.19 132 4.07 <0.13 0.099 <0.05

AB04 6.66 71.6 465 45.9 32.7 77.8 3.38 75.2 184 <0.13 0.043 0.23

AB05 6.8 25 163 11.6 4.43 36.3 3.27 16.7 3.89 0.51 2.55 0.08



Figure 8: Groundwater quality trends of the ash dam boreholes



Coal Stockyard Area:

Borehole CB08 was not sampled during the current monitoring period due to the fact that it is

blocked. The borehole must be cleaned or new borehole drilled.

When compared to the groundwater quality reserve and WUL standards the results indicate

no impact from the coal stock yard of power station (Table 12 and Table 13). All parameters

fall within the groundwater quality reserve and WUL limits.

Table 12: Groundwater quality results of coal stockyard boreholes as compared to the

groundwater reserve quality set in DPD WUL

Locations


Ca mg/l

Mg mg/l

Na mg/l

K mg/l Cl mg/l SO4 mg/l


5-9.5 462 45 24 36 6.5 23 152

Coal

Stockyard Area

CB06 6.69 42.8 6.44 3.97 4.21 2.86 3 3.43

CB07 7.12 89.4 16.1 7.65 10.3 2.96 2.43 10.1

Table 13: Groundwater quality results of the coal stockyard boreholes as compared to

the WUL limits

Locations

Parameters pH EC

mS/m TDS mg/l

Ca mg/l

Mg mg/l

Na mg/l

K mg/l

Cl mg/l

SO4 mg/l

NO3-N mg/l

F mg/l Fe

(mg/l) Mn

(mg/l)

WUL WQOs 5-9.5 2578 1225 930 1213 127 65 150 2359 15 1.5 2 2

Coal

Stockyard Area

CB06 6.69 6.59 42.8 6.44 3.97 4.21 2.86 3 3.43 <0.13 0.463 0.31 0.07

CB07 7.12 13.8 89.4 16.1 7.65 10.3 2.96 2.43 10.1 <0.13 0.136 0.12 <0.05



Figure 9 : Groundwater quality trends of the coal stockyard boreholes



Sewage Plant Area:

The majority of the boreholes at the sewage plant indicate parameters which fall well within

the groundwater quality reserve and WUL limits (Table 14 and Table 15. However, boreholes

PB12 indicate slightly elevated potassium (K) concentration during the current monitoring.

Table 14: Groundwater quality results of sewage plant boreholes as compared to the

groundwater reserve quality set in DPS WUL

Locations


Ca mg/l Mg

mg/l Na

mg/l K mg/l

Cl mg/l

SO4 mg/l


5-9.5 462 45 24 36 6.5 23 152

Sewage Plant Area

PB12 7.58 216 20.6 6.77 15.3 9.26 14.9 3.17

PB13 6.51 142 7.7 5.15 19.6 5.56 19.2 11.6

PB18 7.43 142 18.5 7.62 17.8 4.92 14.9 20.4

Table 15: Groundwater quality results of the sewage plant boreholes as compared to

the WUL limits

Locations

Parameters pH EC

mS/m

TDS

mg/l

Ca

mg/l

Mg

mg/l

Na

mg/l

K

mg/l

Cl

mg/l

SO4

mg/l

NO3-N

mg/l

F

mg/l

Fe

(mg/l)

Mn

(mg/l)

WUL WQOs 5-9.5 2578 1225 930 1213 127 65 150 2359 15 1.5 2 2

Sewage Plant

Area

PB12 7.58 33.2 216 20.6 6.77 15.3 9.26 14.9 3.17 1.99 0.35 <0.05 0.13

PB13 6.51 21.8 142 7.7 5.15 19.6 5.56 19.2 11.6 0.763 0.05 <0.05 0.45

PB18 7.43 21.9 142 18.5 7.62 17.8 4.92 14.9 20.4 0.581 0.15 <0.05 0.28



Figure 10: Groundwater quality trends of the sewage plant boreholes



5. CONCLUSION:

The water qualities represented in this report reflect qualities of water resources that might be

affected by activities undertaken at Duvha Power Station. Ash Dams, Ash Return Water Dams, and

Coal storage areas are some of the areas that can influence or pose a significant risk to water

qualities. Necessary measures are in place in order to minimise these risks. Also, further

investigations and action plans are undertaken on a continuous basis in order to determine the extent

of these risks and mitigation measures thereof.

Precautionary measures are also taken in areas such as Return Water Dams where the dam

levels are monitored on a continuous basis in order to monitor any overflows that might

happen.

Groundwater Levels:

o The topography and groundwater elevation show a high degree of correlation

(99.67%). This indicate that groundwater follows the topography.

o The recorder groundwater levels for October 2016 ranges from 1.18m (AB03) to

5.63m (PB09). All borehole indicate a drop in groundwater level from the previous

monitoring (September 2015).

Water quality results:

Some of the surface water sampling points (AP08 – Witbank Dam, PP03 – emergency pond) indicate

poor water quality due to their elevated Ca, Na, Cl and S04 concentration. However, the elevated

parameters might be attributed to other external influence other than the power station (mines etc)

based on the locations relative to the power station.

Recent groundwater quality results indicates no influence on water qualities emanating from the

power station (including ash dam, coal stockyard etc).

Groundwater samples obtained from boreholes at the sewage treatment plant indicate improvement

in water quality when compared to the WUL limits.



APPENDIX C – Site Pictures



DPS’s Surface water monitoring points set in WUL

AP08 (Witbank Dam) AP09 (Low level ash return water dam)

PE01 (Final Effluent sample – sewage plant)



Some of the groundwater sampling points set out in DPS’s WUL

AB01 (Borehole in good condition) – Ash dam

borehole AB02 (No cap) – Ash dam borehole

AB04 (No marker pole) – Ash dam borehole CB08 (Blocked) – Coal stockyard borehole

Appendix F: Surface and Groundwater Monitoring Report · and anions as well as physical parameters;...

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Transcript of Appendix F: Surface and Groundwater Monitoring Report · and anions as well as physical parameters;...