j.m. dabrowski , j. dabrowski , p. macmillan and l. hill
DESCRIPTION
Assessment of water quality originating from the upper Olifants , Wilge and Klipspruit catchments . J.M. Dabrowski , J. Dabrowski , P. MacMillan and L. Hill. Study Area. Study Approach. Field Sampling Water quality sampling Discharge measurements Algal and sediment sampling - PowerPoint PPT PresentationTRANSCRIPT
Assessment of water quality originating from the upper Olifants, Wilge and Klipspruit catchments.
J.M. Dabrowski, J. Dabrowski, P. MacMillan and L. Hill
Study Area
Study Approach
• Field Sampling– Water quality sampling– Discharge measurements– Algal and sediment sampling– SASS sampling– Toxicity bioassays
• Data analysis– Dissolved vs suspended (colloidal)– Speciation of metals– Calculation of loads (Olifants, Klipspruit and Wilge)– Bioaccumulation by algae– Ecological health (macroinvertebrate indices)
• Outcomes– Fate, transport, speciation of metals in Olifants River– Relative contribution of metals to Loskop Dam from upper Olifants, Klipspruit and Wilge
catchments
General Water Quality
OL1 KL2 OL3 OL4 OL5 OL6 WG7 OL80
100
200
300
400
500
600
700
TDS (mg/l)
SulphateCarbonateChlorideCalciumMagnesiumPotassiumSodium
OL1 KL2 OL3 OL4 OL5 OL6 WG7 OL80
1
2
3
4
5
6
7
8
9
pH
Aluminium - Al
OL1 KL2 OL3 OL4 OL5 OL6 WG7 OL80
100
200
300
400
500
600
Al - Concentrations (ug/l)
TotalDissolved
OL1 KL2 OL4 OL_6 WG7 OL_80
5
10
15
20
25
30
Al - Load (kg)
Iron - Fe
OL1 KL2 OL3 OL4 OL5 OL6 WG7 OL80
20
40
60
80
100
120
140
Fe - Concentrations (ug/l)
TotalDissolved
OL1 KL2 OL4 OL_6 WG7 OL_80
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Fe - Load (kg)
Manganese - Mn
OL1 KL2 OL3 OL4 OL5 OL6 WG7 OL80
100
200
300
400
500
600
Mn - Concentrations (ug/l)
TotalDissolved
OL1 KL2 OL4 OL_6 WG7 OL_80
5
10
15
20
25
30
35
40
Mn - Load (kg)
Zinc - Zn
OL1 KL2 OL3 OL4 OL5 OL6 WG7 OL80
2
4
6
8
10
12
14
16
18
Zn - Concentrations (ug/l)
TotalDissolved
OL1 KL2 OL4 OL_6 WG7 OL_80
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
Zn - Load (kg)
Metals in Algae
OL1 OL3 OL4 OL5 OL6 WG7 OL80
1000
2000
3000
4000
5000
Aluminium (mg/kg)
OL1 OL3 OL4 OL5 OL6 WG7 OL80
1000
2000
3000
4000
5000
Iron (mg/kg)
OL1 OL3 OL4 OL5 OL6 WG7 OL80
2000400060008000
100001200014000
Manganese (mg/kg)
OL1 OL3 OL4 OL5 OL6 WG7 OL80
50100150200250300350400450
Zinc (mg/kg)
Toxicity – Daphnia magna
OL1 KL2 OL3 OL4 OL5 OL6 WG7 OL80
10
20
30
40
50
60
70
80
% Mortality (Daphnia magna)
SASS
Conclusions
• Klipspruit River contributes up to 100 times more loads of dissolved metals in comparison to entire upper Olifants and Wilge catchments.
• The Klipspruit River results in a deterioration of water quality and ecosystem health in the Olifants River.
• Dissolved metal loads decrease longitudinally indicating precipitation and incorporation into bed sediment.
• Toxicity detected at OL1 indicates the presence of a contaminant that may not have been measured.
• The Wilge River bares low loads of metals and significantly improves water quality and associated ecosystem health in the Olifants River.