Original EA Amendment

Sub catchment Heritage Minerals activities

Potential Scenarios

Likely localised changes to groundwater flow directions

and expressions in mine target area “pits” removing

catchment from existing sumps. Ground inflow to mine

target area “pits” will be high in the short term and will

reduce along with OCP water levels.

Likely reduced seepage volumes to Mundic and Frog

Hollow sumps in medium to long term (reduced recharge

and localised changes to groundwater catchments).

Reactivation of Airfield Dump

Improved surface water drainage reducing infiltration and

subsequent poor-quality seepage via careful placement,

compaction, shaping and capping of ARD waste rock by

placement of overlying NAF waste rock.

Potential for seepage water quality to further degrade in

short term (reduced recharge), draining and expressing to

Mundic West and Frog Hollow sumps.

Likely reduced poor-quality seepage to Mundic West and

Frog Hollow sumps in medium to long term (reduced

recharge).

Light of Day

Nil

Nil

Shepherds

Mining Shepherds tailings

Improved surface water drainage reducing infiltration and

subsequent poor-quality seepage via removal of ARD

generating mine waste (tailings).

Potential for seepage water quality to improve in short

term (ARD source removal), draining and expressing to

Shepherds sumps.

Likely reduced poor-quality seepage volumes to

Shepherds sumps in medium to long term (reduced

recharge).

Remediation of Shepherds

Improved surface water drainage reducing infiltration and

Outer Dump

subsequent poor-quality seepage via careful placement,

compaction, shaping and capping of ARD waste rock by

placement of overlying NAF waste rock.

Potential for seepage water quality to further degrade in

short term (reduced recharge), draining and expressing to

Shepherds sumps.

Likely reduced poor-quality seepage to Shepherds sumps

in medium to long term (reduced recharge).

In summary, there is likely to be reduced inflows into existing sumps from groundwater and sub-surface

flows in comparison to those under existing conditions. This is expected to result in improved

124

Wulguru Technical Services Pty Ltd – Supporting Information to Amend an Environmental Authority

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