Environmental Assessment
Volume E-3.10
Tailings Facility
Water Quality
Ambatovy Project
134
January 2006
Table 3.10-3 Maximum Predicted Water Quality Concentration From Tailings Area
Versus Baseline and Guideline Values
Operations Scenarios
Post-Closure Scenarios
Parameter
Baseline
WHO
Drinking
Water
Guidelines
(a)
South Africa
Aquatic
Ecosystems
Guideline
(b)
Baseline
WHO
Drinking
Water
Guidelines
(a)
South Africa
Aquatic
Ecosystems
Guidelines
(b)
conductivity
√
NG
NG
√
NG
NG
total alkalinity as CaCO
3
-
-
nitrate (NO
3
)
√
-
NG
√
-
NG
nitrite (NO
2
)
-
-
calcium (Ca)
√
NG
NG
√
NG
NG
chloride (Cl)
-
-
magnesium (Mg)
√
NG
NG
√
NG
NG
sodium (Na)
-
-
sulphate (SO
4
)
√
NG
NG
√
NG
NG
aluminium (Al)
-
-
arsenic (As)
-
-
barium (Ba)
-
-
chromium (Cr)
-
-
cobalt (Co)
√
NG
NG
√
NG
NG
copper (Cu)
√
-
●
√
-
●
iron (Fe)
√
NG
NG
√
NG
NG
lead (Pb)
-
-
manganese (Mn)
√
-
●
√
-
●
mercury (Hg)
-
-
nickel (Ni)
-
-
silicon (Si)
√
NG
NG
-
vanadium (V)
-
-
zinc (Zn)
√
NG
●
-
(a)
World Health Organization Drinking Water Guidelines (WHO 2004).
(b)
South Africa Ecosystems Guideline (Department of Water Affairs and Forestry 1996).
-
Not above baseline (less than 10% difference between baseline and maximum predicted concentration or
guideline value).
√
Project-related changes in water quality concentrations are above baseline values by 10% or greater.
●
Above guideline.
Blank cell Not compared to guidelines when projected-related activities results in less than 10% difference in maximum
predicted concentration compared to baseline value.
NG
No applicable guideline.
For the post-closure scenarios (i.e., 15 and 80 years after closure), eight out of the
twenty-three modelled parameters were above baseline concentrations
(Table 3.10-4). Out of these eight parameters above baseline, none were above
WHO drinking water guidelines and only copper and manganese were greater
than South African Aquatic Ecosystems Guidelines. The predicted increase in
