47 PART 5: DATA COLLECTION AND METHODOLOGY 5.1. DATA COLLECTION: Existing data that were collected during the literature review as well as site investigation of the study area. The existing data include maps of the study area as well as previous studies conducted on the area. With the knowledge gained from the literature review as well as an investigation of the study area, the water quality conditions of the Hex River catchment can now be established. Water quality data for a four year period (July 2002 to June 2006) is used to ascertain whether the conditions of the Hex River and its primary tributaries have deteriorated over time. The selected period of four year includes the most recent water quality data and includes all seasons, winter, spring, summer and autumn, and well as wet and dry periods. The most recent water quality data are used to determine the current water quality conditions of the study area as well and its suitability with regards to domestic use, irrigation and livestock watering as well as its fitness for the aquatic environment. For the purpose of this study the annual average water quality were calculated so that average conditions of the past can be compared to the most recent conditions. Water quality management includes the processes of sampling, measurement, recording and analysis (Huang & Xia, 2001). Analytical data are required to indicate the quality of water by determination of parameters such as the concentrations of inorganic material, dissolved minerals or chemicals, dissolved gases, dissolved organic material, and matter suspended in the water or bottom sediments at a specific time and localities or over a specific time interval at a particular location (ISO 5667-2:1991 (E)). Quantitative data of the physical, chemical and biological constituents (Table 9, p. 48) of the Hex River and its primary tributaries (Table 10, p.49) as collected by routine sampling during the monitoring period were obtained from Clean Stream Environmental Services (CSES). For any resource be it a dam, river or aquifer a specific profile of users has developed over time (Barnard, 1999). A water user survey (Clean Stream Environmental Services, 1999) was conducted with the Target Water Quality Guidelines in mind, to identify the various water users adjacent to the Hex River. The Target Water Quality Guidelines Ranges (TWQGR) for various water uses including domestic use, livestock watering, irrigation and aquatic ecosystems will be used to identify the suitability of use of the water in the Hex River. The protection and management of water resources
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47
PART 5: DATA COLLECTION AND METHODOLOGY
5.1. DATA COLLECTION:
Existing data that were collected during the literature review as well as site investigation of the study
area. The existing data include maps of the study area as well as previous studies conducted on the
area. With the knowledge gained from the literature review as well as an investigation of the study
area, the water quality conditions of the Hex River catchment can now be established. Water quality
data for a four year period (July 2002 to June 2006) is used to ascertain whether the conditions of the
Hex River and its primary tributaries have deteriorated over time. The selected period of four year
includes the most recent water quality data and includes all seasons, winter, spring, summer and
autumn, and well as wet and dry periods. The most recent water quality data are used to determine the
current water quality conditions of the study area as well and its suitability with regards to domestic
use, irrigation and livestock watering as well as its fitness for the aquatic environment. For the purpose
of this study the annual average water quality were calculated so that average conditions of the past can
be compared to the most recent conditions.
Water quality management includes the processes of sampling, measurement, recording and analysis
(Huang & Xia, 2001). Analytical data are required to indicate the quality of water by determination of
parameters such as the concentrations of inorganic material, dissolved minerals or chemicals, dissolved
gases, dissolved organic material, and matter suspended in the water or bottom sediments at a specific
time and localities or over a specific time interval at a particular location (ISO 5667-2:1991 (E)).
Quantitative data of the physical, chemical and biological constituents (Table 9, p. 48) of the Hex River
and its primary tributaries (Table 10, p.49) as collected by routine sampling during the monitoring
period were obtained from Clean Stream Environmental Services (CSES).
For any resource be it a dam, river or aquifer a specific profile of users has developed over time
(Barnard, 1999). A water user survey (Clean Stream Environmental Services, 1999) was conducted
with the Target Water Quality Guidelines in mind, to identify the various water users adjacent to the
Hex River. The Target Water Quality Guidelines Ranges (TWQGR) for various water uses including
domestic use, livestock watering, irrigation and aquatic ecosystems will be used to identify the
suitability of use of the water in the Hex River. The protection and management of water resources
48
usually impose different requirements on water quality and thus the associated water quality objectives
for each use are different (WHO/UNEP, 1997).
Table 9: Water Quality constituents affecting domestic use, irrigation, livestock watering and the
aquatic environment analysed for the Hex River and its primary tributaries.
WATER QUALITY CONSTITUENTS
Chemical Constituents Physical Constituents Biological Constituents
Locality Description: Eastern inflow into Klipfontein Return Water Dam (Impact from the eastern tailings dams of the Klipfontein Tailings Complex)
Catchment: Klipfontein
Type: Dam
Coordinates: S25.6983/ E27.3619
Locality Description: Klipfonteni Dam (Aggregate of upstream catchment: Klipfontein Tailings Complex, stromwater from Temso and engineering workshops, Blesbok shaft spillage, Klipfontein
sewage effluent)
Catchment: Klipfontein
Type: Spruit
Coordinates: S25.41399/ E27.3531
Locality Description: Klipfontein Spruit downstream of Klipfontein Dam
Catchment: Klipfontein
Type: Spruit
Coordinates: S25.6765 / E27.31723
Locality Description: Klipfontein downstream of Waterval Smelter
Catchment: Klipfonten
Type: Spruit
Coordinates: S25.6525/ E27.2961
Locality Description: Naude Dam (Aggregate impact on the Klipfontein Spruit)
Catchment: Klipfontein
Type: Spruit
Coordinates: S25.6525 / E27.2961
Locality Description: Seepage from Naude Dam (Aggregate Klipfontein Spruit impact prior to confluence with Hex River)
Klipf1Klipf1
Klipf2Klipf3
Klipf4
Klipf5
Klipf6
Klipf2
Klipf3
Klipf4Klipf5Klipf6
1: 50 000
27'20'E
25'4`S
Figure 22: Illustrated map indicating the location of monitoring localities (Klipf1 - Klipf6) as well as locality names, description,
coordinates situated within the Klipfontein Spruit.
61
The Temso pond, from the Temso engineering workshop is frequently contaminated by oils and
greases however this is not included in the scope of the study. Surface water runoff from a shaft enters
the Klipfontein Spruit upstream of the old Klipfontein waste water treatment works. Spillage from
sewage lines is likely to impact on this part of the Klipfontein Spruit.
Bleskop Shaft storm
Klipfontein Dam
Hospital run-off
Klipfontein WWTW pump station overflow
Waste dump
Tar dams
Klipfontein WWTW pump station overflow
Waste dump
Tar dams
Temso pond
Klipfontein Complex Runoff
Figure 23: Impacts from mining related as well as waste water impacts on the Klipfontein Spruit
(Clean Stream Environmental Services, 2003).
• Klipf3- Klipfontein Spruit downstream of Klipfontein Dam. Monitoring locality Klipf3 is
situated just downstream of the Klipfontein Dam and indicated mining related impacts
downstream of the Klipfontein Dam. These impacts include process or storm water discharge
from the precious metal refinery situated in close proximity of the locality as illustrated in
Figure 24, p. 61.
PMR storage dams
PMR stormwater discharge
PMR process water discharge
PMR process water discharge
Tar dams
PMR storage dams
PMR process water discharge
PMR process water
Tar dams
Figure 24: Mining activities impacting on the Klipfontein Spruit downstream of the Klipfontein
Dam at sampling locality Klipf3.
• Klipf4- Klipfontein Spruit downstream of mining related smelter. Monitoring locality Klipf4
indicate water quality impacts from mining related activities originating at the base metal
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refinery, smelter as well as acid Plant converter used in platinum mining operations as well as
the new Klipfontein Spruit waste water treatment works indicated in Figure 25, p. 62
UG2 Dams
Klipfontein WWTW discharge
Waterval concentrator pollution dam
Waterval Pollution control dam
Waterval tailings seepage zone
BMR Rain Water Dams
& stormwater
trench
ACP Storm water trench
Storm water trench at railway
Industrial process water
Explosives magazine
Figure 25: Mining activities impacting on the Klipfontein Spruit downstream of the Klipfontein
Dam at sampling locality Klipf4 (Clean Stream Environmental Services, 2003).
• Klipf5- Naude Dam. Monitoring Locality Klipf5 indicate water quality conditions within the
Naude Dam. According to Clean Stream Environmental Services the impact towards the Naude
Dam is directly ascribed to overflow from the sludge settling dams as well as seepage as can be
seen in Figure 26, p. 62. The rock dump as well as Shaft area situated close to the Naude Dam
is a noteworthy pollution sources. A highly populated informal settlement situated next the shaft
can cause additional adverse effects on the water quality of the Paardekraal Spruit.
Naude Dam
Sludge settling dams
Rock dump toe
Cementation Plant
Discharge
Figure 26: Mining related impacts on the Klipfontein Spruit in the vicinity of the Naude Dam
(Clean Stream Services, 2003).
• Klipf6- Seepage from Naude Dam. Sampling locality Klipf6 indicate the aggregates water
quality impacts from the Klipfontein spruit prior to its confluence with the Hex River.
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5.2.5. MONITORING LOCALITIES SITUATED WITHIN THE HEX RIVER
N
Paardekraal Spruit
Klipgat Spruit
Dorp Spruit
Klipfontein Spruit
Mining activities
Wastewater Treatment
Works
Hex1Catchment: Hex
Type: River
Coordinates: S25.6957/ E27.3071
Locality Description: Hex River - upstream of Waterval Mine (Background conditions prior to mining impact)
Hex2Catchment: Hex
Type: River
Coordinates: S25.68383 / E27.28625
Locality Description: Hex River - upstream reference locality
Catchment: Hex
Type: River
Coordinates: S25.8303/ E27.2850
Locality Description: Hex River at road to Rustenburg (Upstream unimpacted conditions in the Hex River)
Hex4Catchment: Hex
Type: River
Coordinates: S25.6616/ E27.2900
Locality Description: Hex River at road to Naude Dam (Impact on Hex River Upstream of Naude Damr)
Catchment: Hex
Type: River
Coordinates: S25.38'984 / E27.17'448
Locality Description: Paardekraal Angling Dam (Hex River prior to Klipfontein Spruit contribution)
Catchment: Hex
Type: River
Coordinates: S25.37'991/ E27.17'420
Locality Description: Hex Riveron bridge between Klipfontein an Klipgat Spruit (Downstream conditions in Hex River after Klipfontein Spruit confluence. Upstream conditions in Hex River prior to Klipgat Spruit confluence)
Catchment: Hex
Type: River
Coordinates: S25.6219 / E27.2896
Locality Description: Hex River downstream of Dorp Spruit confluence (represents impact of Dorp Spruit on Hex River)
Catchment: Hex
Type: River
Coordinates: S25.6092/ E27.2992
Locality Description: Hex River between Klipgat and Paardekraal Spruit (Downstrea conditions in the Hex River after Klipgat Spruit confluence. Upstream conditions in the Hex River prior to Paardekraal Spruit confluence)
Catchment: Hex
Type: River
Coordinates: S25.5922 / E27.29887
Locality Description: Hex River downstream of Paardekraal Spruit confluence
Catchment: Hex
Type: River
Coordinates: S25.5531 / E27.3076
Locality Description: Hex River before Bospoort Dam (Aggregate impact on Hex River just upstream of the Bospoort Dam)
Catchment: Hex
Type: Dam
Coordinates: S25.5708 / E27.3589
Locality Description: Bospoort Dam (Aggregate impact on the receiving water body)
Hex2
Hex3Hex1
Hex4
Hex5Hex6
Hex7
Hex8
Hex9
Hex10
Hex11
Hex2
Hex3
Hex1
Hex4
Hex5
Hex6
Hex7Hex8
Hex9 Hex10 Hex11
1: 50 000
27'19'E
25'37'S
Figure 27: Illustrated map indicating the location of monitoring localities (Hex1 - Hex12) as well
as locality names, description, coordinates situated within the Hex River.
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The purpose of this study is to determine the water quality conditions of the Hex River (see Part1, p 1
to 5). To meet this purpose twelve monitoring localities situated within the Hex River were identified
and included in the study. The location of these localities within the Hex River id presented in Figure
27, p. 63 and a description of these localities follow below.
• Hex1- Hex River upstream of Waterval Mine. Monitoring locality Hex1 indicates the upstream
water quality of the Hex River. Possible impacts situated upstream from monitoring locality
Hex1 include agricultural activities as well as chrome and platinum mining activities.
• Hex2- upstream reference locality. Monitoring locality Hex2 is the upstream reference locality
prior to mining related impacts on the Hex River.
• Hex3- Hex River at road to Rustenburg. Monitoring locality Hex3 indicate upstream unaffected
water quality conditions.
• Hex4- Hex River at road to Naude Dam. Sampling locality Hex4 indicate upstream water
quality before the Naude Dam confluence.
• Hex5- Paardekraal Angling Dam. Water quality conditions within the Paardekraal Angling
Dam situated within the Hex River are indicated by monitoring locality Hex5. The Paardekraal
Angling Dam is situated prior to the confluence of the Hex River with the Klipfontein Spruit.
• Hex6- Hex River bridge between Klipfontein- and Klipgat Spruit. Monitoring locality Hex6
indicates downstream water quality conditions after the confluence with the Klipfontein Spruit
but before the confluence with the Klipgat Spruit. Thus locality Hex6 in indicative of water
quality impacts from mining related activities situated in the Klipfontein Spruit on the water
quality of the Hex River. Another water quality impact reporting to the locality Hex6 is
discharge from the waste water treatment works as can be seen in Figure 28, p. 65.
65
Rustenburg WWTW Sludge dams
discharge
Rustenburg WWTW Maturation ponds
discharge
Rustenburg WWTW Maturation pond
discharge
Figure 28: Impacts from the Rustenburg waste water treatment works on the Hex River (Clean
Stream Environmental Services, 2003).
• Hex7- Hex River downstream of Dorp Spruit confluence. Monitoring locality Hex7 indicates
water quality impacts on the hex River from its tributary the Dorp Spruit as well as the Klipgat
Spruit.
• Hex8- Hex River between Klipgat- and Paardekraal Spruit. Monitoring locality Hex8 indicates
the water quality conditions after the confluence of the Hex River with the Klipgat Spruit but
prior to its confluence with the Paardekraal Spruit. Thus monitoring locality Hex8 is indicative
of the water quality impacts originating in the Paardekraal Spruit.
• Hex9- Hex River downstream of Paardekraal Spruit confluence. The water quality conditions of
the Hex River after its confluence with the Paardekraal Spruit are indicated by monitoring
locality Hex9.
• Hex10- Hex River before Bospoort Dam. Monitoring locality Hex10 indicate the aggregate
impact from the tributaries as well as activities situated within the Hex River just prior to the
receiving water body, the Bospoort Dam.
• Hex11- Bospoort Dam. The water quality conditions of the Bospoort Dam are represented by
monitoring locality Hex11.
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5.3. METHODS OF DATA COLLECTION:
Representative water sampling was taken on a monthly basis by Clean Stream Environmental Serivces
for various localities within the Hex River and its tributaries. A representative water sample can be
described as: “A sample taken in the correct manner at a point that truly represents the water body at
the time, at the specific locality of concern.” Data was collected by qualified environmental
technicians from Clean Stream Environmental Services by using the grab sample method. According
to ISO 5667-2:1991 grab samples are samples manually collected but can also be collected
automatically for water at the surface. Each sample is representative of the water quality only at the
time and place at which the samples were taken. Grab samples are used if the flow of the water to be
sampled is not uniform, if the values of parameters of interest are not constant, and if use of a
composite sample would obscure differences between individual samples due to the reaction between
them. A grab sample represents non-point pollution transport only at the time of sampling. Monthly
and quarterly grab samples were collected by Clean Stream Environmental Services at the various
monitoring localities as specified in Table 9, p.48. A monthly sampling frequency gives a good
indication of prevailing environmental conditions as well as seasonal variation.
In accordance with SABS guidelines 5667-1 to 5667-3 a sample data sheet must be completed for each
sample. These should typically include the following information:
• Location and name of the sample site
• Details of the sampling point i.e. surface/ underground water
• Method of collection
• Time of collection
• Name of sampler
• Weather conditions
• Nature of pre-treatment, if any
• Preservative or stabilizer added, if any
• Comments and other data gathered at this point, if any
According to Fuggle & Rabie (2003) the storage, type of container used, the time elapsed between
sampling and analysis, and whether preservatives are used must be recorded unequivocally for grab
67
sampling. Water samples were collected in new clean polyethylene bottles and stored in dust free
thermo-isolated containers. Samples are not being preserved after sampling, as new and clean sampling
bottles are used cross-contamination is minimal. Separate samples should be used for chemical
microbiological and biological analyses, because of the procedure and equipment used for handling and
collection varies.
5.3.3. INORGANIC SAMPLING:
For the purpose of determining the inorganic components of the samples, non-acidified samples are
taken in new clean 1-litre polyethylene sampling containers, after it had been pre-contaminated by
rinsing with the water to be sampled. The container is filled to the brim and sealed. The sample is
immediately placed in a thermo-isolated cooler box and later stored in a fridge. After sampling, the
samples are delivered by the environmental technicians from Clean Stream Environmental Services to
the laboratory, Mpumamanzi Laboratory Services within 24-28 hours for the required analyses.
5.3.4. MICROBIOLOGICAL SAMPLING:
For the purpose of determining the potential bacteriological components of the samples, non-acidified
sampled are taken in 50 ml, sterilized glass or plastic sample bottles after being pre-contaminated by
rinsing with the water to be sampled. Surgical gloves must be worn for the collection of these samples.
The container is filled to the brim and sealed. The sample is placed in a cooler box immediately and
later stored in a fridge. On returning from the field visit, the samples are immediately delivered to the
Mpumamanzi Laboratory for the required analyses.
5.4. SHORTCOMINGS OF DATA:
Fitfield and Haines (1996) listed the flowing shortcomings in data collection which can be applied to
this study:
• Sampling and sampling handling
• Analytical method
• Faulty instrumentation
• Mistakes by operators
68
According to Venter (2004) the sampling of water is a vital part in the study of natural water
composition, and is further the main source of error in obtaining accurate water quality information.
Only liter samples are taken to represent the whole substance under consideration and this creates
inherently uncertainty because of possible sampling errors. The homogeneity of the water and the size
of the sample determine how reliable and representative the sample is of the whole water body. The
sample bottles used in this study were collected in 1 liter sterilized plastic containers.
The data for long-term trends were collected over a four year period (July 2002 to June 2006), and
those for the current water quality situation for a period of one year (July 2005 to June 2006). Samples
were taken at monthly intervals except when the monitoring locality was recorded as dry, no flow
conditions were recorded or no access to the monitoring locality were available. To establish accurate
spatial and temporal trends for a water body, samples should be taken every month at the same time
and more sampling should be conducted during the wet season (SABS, 1984). The following
shortcomings were present in the data:
• There are no data available for the Dorp Spruit monitoring localities during the period July
2002 to December 2002. Thus the annual average data calculated for the 12 months period from
July 2002 to June 2003, represents only seven months worth of data. The reason for the
unavailability of this data in unbeknown to the researcher.
• Sampling locality Klipg1, situated within the Klipgat Spruit was not sampled between the
period Jul 2002 to January 2003. Monitoring localities Klipg2 and Klipg3 were not sampled
during the period September 2002 to November 2002. These gaps in data could have a
influence on the calculation of the annual averages.
• Water quality data for monitoring localities Paarde1 and Paarde2 situated within the Paardkraal
Spruit are limited to four datasets recorded during March, April, June and October 2004. No
annual average values could be recorded for these localities during July 2002 to June 2003 as
well as July 2005 to June 2006. Further monitoring locality Paarde4 was not sampled during
July 2005 to June 2006, and thus no current annual average water quality could be calculated
69
for this locality. The lack in data for these monitoring localities can be ascribed to no flow or
dry conditions prevailing within the Paardekraal Spruit at limiting sampling.
• Data values for the chemical variables Copper, Chromium, Cobalt, Cadmium, Nickel and Zinc
were limited over the monitoring period due to the periodic sampling and analysis of these
variables. These variables were however not included in the discussion on water quality
conditions in Part 6, p 73 to 131 of this study.
• Limited bacteriological data were available for the tributaries of the Hex River. Therefore only
the bacteriological water quality of the sampling localities situated within the Hex River will be
discussed in Part 6, p. 73 to 131 of the study.
Even though shortcomings in the data exists, the annual average data calculated for the monitoring
period are considered as representative values for the prevailing water quality conditions experienced
in the Hex River and its associated tributaries. The methods used for the analysis of the water quality
data obtained during the four year sampling period as well as the interpretation of the data are
discussed in the following sections below.
5.5. METHODS USED TO ANALYZE DATA:
Inorganic water samples were analyzed according to recognized procedures and approved laboratory
analysis as represented in Table 11, p. 70 below. Water samples collected by Clean Stream
Environmental Services are analyzed by Mpumamanzi Laboratory services. This laboratory is widely
used by the mining industry for water analyses and is also contracted to perform analytical services for
the Department of Water Affairs and Forestry. Mpumamanzi Laboratory is an SANAS accredited
laboratory. Collected water samples are kept refrigerated until analysis of the samples is undertaken.
Analysis was carried out on accordance with methods as summarized in Table 11, p 70, prescribed by
and obtainable from the South African Bureau of Standards.
70
Table 11: Methods used for the analysis of selected constituents.
VARIABLE SABS
METHOD ANALYSIS METHOD DESCRIPTION
ANALYSIS METHOD INSTRUMENT
UNITS LOWER
DETECTION LIMIT
UPPER DETECTION
LIMIT Turbidity SABS 197 Shake sample well, read on turbidity meter Turbidity meter, NTU 0.01 200
pH SABS 11 Agitate sample Metrohm/ pH meter, use magnetic stirrer
pH units 14
Conductivity SABS 1057 Adjust temperature/ measure the resistance of the sample
Hanna Conductivity meter mS/m
Total dissolved solids
SABS 213 Dry filtered sample at 180 degrees for 2 hours Labcon Oven mg/l
Total hardness SABS 215 EDTA tritrimetric/ use of ethylenediaminetetraacetic acid (EDTA) or its
sodium salt as titrating agent
Visual and point tritation mg/l 0.1
Calcium SABS 1265 Flame absorption spectrometry Varian Spectra A 10 Plus mg/l 50
Magnesium SABS 1265 Flame absorption spectrometry Varian Spectra A 10 Plus mg/l 5
Sodium SABS 1050 Flame absorption spectrometry Varian Spectra A 10 Plus mg/l 1 50
Potassium Standard method 317
Flame absorption spectrometry Varian Spectra A 10 Plus mg/l 0.1 20