Tui Mine Remediation Project
Details about the
mine
The Tui mine is an abandoned mine in the
Kaimai Range of New Zealand on the western slopes of Mount Te Aroha. Following
the cleanup of the former Fruitgrowers Chemical Company site at Mapua, it was deemed
to be the most polluted site in the world. the mine owner is Norpac mining. the
mine is started in 1960 and its extract copper, lead, and zinc sulfides.
the mines works were stopped in 1973. the mining company dumps waste rocks ore
and mine tailings behind a dam. the tailing contains a significant amount of
Zinc and Cadmium. because of the waste dumping, the water of the pool is completely
contaminated and acidic .in 1997 there are no natural plants in the pool due to
the high contamination.
Environmental issues occurred due to the Tui mine
v The heavy metals lead and cadmium was leaching from the dam to the Tunakohoia stream which flows through the Te Aroha town center. And the water supply of the town is also contaminated with heavy metals.
v A separate catchment area near to the mine and the dam was also contaminated with heavy metals
v The separate catchment of the mine is also provided a huge risk. In heavy rain, the catchment area water can be leakage into the river stream.
The remediation project of the Tui
mine
The project was announced in 2007 by
the New Zealand government. the government funding is $9.88 million and the government
set up the project ending time to 2010.
the estimated cost of the project is $17.4 million and the mine site
cleaning was complete in 2013, at a total cost
of $21.7 million. All costs are funding by the central government.
Remediation technologies used for this
project
v An in-situ mixing of concrete and 0 lime (CaCo3) into the mining tailings to stabilize the liquid landfill and enable the ongoing management of the tailings dam.
v Using the lay of the land and natural drainage patterns to flow surface water flows around the contamination prevents further contamination of clean water. While allowing for treatment of contaminated groundwater coming from the site.
v
After the fixing dam, the grass is introduced
to the land and creates an ecosystem like previously.
Monitoring Parameters and measurement methods
|
Parameters |
sites |
Method |
Detection
level |
||
|
Physicochemical |
Field Temperature,pH,conductivity ORP,
dissolved oxygen, turbidity |
All
water quality sites |
Calibrated
field meters/s |
- |
|
|
Laboratory pH,conductivity,total
suspended solids |
All
water quality sites |
|
- |
||
|
cyanide |
SW11,
SW13, and SW 15 |
Total
recoverable |
0.001
g/m3 |
||
|
Total
and dissolved trace elements |
Al,Sb,As,Ba,Be,B,Cd,Ca Cr,Cu,Fe,Pb,La,Mg,Mn, Hg,Mo,Ni,K,Se,Ag,Na,Sn U,ZN |
All
water quality sites |
Field
filter for dissolved metals Total
recoverable metals |
Trace |
|
|
Anions
and cations |
Ca,Mg,total
hardness,,K,Alkalinity and bicarbonate,carbonate and Co2,NO3,NO2,So4,Cl,Total dissolved
silica |
SW3.
SW5, SW 100, SW101 |
Field
filtered |
- |
|
After the project complete The monitoring section is started. Tui mine remediation project is monitored
according to the below sections.
v
Biological and water quality monitoring
v
Air discharge monitoring plan
v
Environmental monitoring plan
Tui mine monitoring plan is done
according to the above sections.
Current situation of the Tui mine
after the remediation
Great
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