Environmental Assessment
Volume E-3.7
Tailings Facility
Hydrogeology
Ambatovy Project
52
January 2006
•
Zinc (HG3 & HG5)
- occurs in small amount in almost all igneous
rocks such as gneiss.
Based on the sample results, groundwater in the proposed tailings disposal
facility area could be subdivided into the following types:
•
HG1 - Mg, Ca, Na - HCO
3
dominant water;
•
HG2 - Mg, Ca, Na - Cl, HCO
3
dominant water;
•
HG3 - Na - HCO
3
dominant water;
•
HG5 - Na, Mg (Ca) - HCO
3
dominant water; and
•
HG6 - Mg, Ca (Na) - HCO
3
dominant water.
Groundwater use in the vicinity of the proposed tailings facility is mainly via
spring/seeps, with only one hand dug well identified within the facility footprint.
No motorized or mechanical abstraction boreholes have been identified in the
immediate vicinity of the tailings facility.
3.7.4
Issue Scoping
The main potential issues relating to hydrogeology are:
•
changes to the groundwater system (flow and chemistry) due to
placement of the tailings materials and subsequent seepage into
groundwater; and
•
effects the changes to the groundwater system may have over the long
term to people or the environment.
The Key Questions for the effects on hydrogeology surrounding the tailings
facility are:
Key Question HG-1
What Effect Will the Tailings Facility Have on
Groundwater Flows and Consequently
Downstream Surface Flows?
Key Question HG-2
What Effect Will the Tailings Facility Have on
Groundwater Quality?
The consequent question to Key Question HG-2 is what effect groundwater
quality will have on surface water quality. The effect of the tailings facility on
surface water quality is addressed in Volume E, Section 3.10.
