Environmental Engineering Reference
In-Depth Information
Projected End-Use
The. potential. for.two. main. end-uses. of.the.rehabilitated. TSF. were. investi-
gated..The.irst.involved.the.growing.of.eucalypts.for.the.production.of.ire-
wood.(in.short.supply.in.Victoria),.and.the.extraction.of.cineole.(the.largest.
producer.of.reined.eucalyptus.oil.is.presently.China,.while.Australia.pro-
duces.only.5%-10%.of.world.production)..The.second.strategy.to.be.trialed.
was. the. growth. of. native. grass. species,. which. can. provide. more. drought-
resistant.and.low-maintenance.pasture.than.introduced.grasses,.and.could.
serve. either. as. grazing. or. as. a. source. of. native. grass. seed. that. is. increas-
ingly.dificult.to.obtain.for.use.in.environmental.rehabilitation.and.is.a.high.
priced.commodity.(>Aus$.200/kg).
Cover Materials
Previous. attempts. to. cultivate.
Eucalyptus
. species. and.
Echinochloa esculenta
.
(Japanese.millet).directly.upon.the.oxidized.surface.of.Tailings.Dam.No..1,.
with.no.amendment.other.than.addition.of.slow.release.fertilizer,.had.proved.
unsuccessful..Planting.on.unamended.tailings.was.included.in.the.present.
study.to.provide.control.for.the.main.protocols.that.involved.application.of.
one,.or.more,.locally.available.materials.to.produce.a.cover.of.<50.cm.thick-
ness.to.support.vegetation.
The.materials.employed.in.the.trial.covers.were.as.follows:
•.
Oxide waste
:.A.waste.rock.stockpile.resulting.from.former.open-cut.
mining.of.the.oxidized.zone.with.an.estimated.volume.of.2.5.million.
m
3
..This.represents.the.largest.local.source.of.future.capping.mate-
rial. and. is. suficient. to. create. a. 25.cm. thick. surface. cover. over. the.
inal.area.of.the.TSF..The.oxidized.and.heavily.leached.waste.rock.
was.milled.to.produce.a.ine.material.that.was.shown.in.glasshouse.
trials.to.be.chemically.benign.
•.
Stabilized biosolids
:. Municipal. sewage. sludge. from. the. Northern.
Grampians. Water. Corporation. wastewater. treatment. plant. at.
Stawell..The.biosolids.had.been.stockpiled.in.a.paddock.for.a.mini-
mum.of.2.years.after.removal.from.anaerobic.digestion.and.matura-
tion. ponds.. After. transport. to. the. experimental. sites,. the. biosolids.
were.spread.in.small.stockpiles.to.allow.aeration.prior.to.application.
on.trial.plots.
•.
Topsoil
:. A. limited. amount. of. topsoil. stored. on. the. mine. site..
Unfortunately,.former.mining.practice.did.not.recognize.the.value.
of.topsoil.for.future.rehabilitation,.and.the.amounts.stockpiled.are.
insuficient.to.cover.the.TSF.(Tailings.Dam.No.2).with.a.layer.10.cm.
thick,.as.employed.in.treatments.in.this.study.
Search WWH ::
Custom Search