2008 02 february

like sand through an hourglass
...this is the soil to rehabilitate our mine
alcoa anglesea
2008
environment report
february
ANGLESEA ENVIRONMENT REPORT FEBRUARY 2008
air
Air Monitoring
Stack Monitors
Average
Maximum
Opacity g/m3 10-minute average
0.069
0.099
Stack SO2 kg/min 1-hour average Licence limit 111.34kg/min 76.30
90.74
Ambient Monitors
SO2 1 hour ppb
Average
Maximum
Community Centre
<1
23
Primary School
1
129
Mt Ingoldsby
4
26
Scout Camp
1
104
Camp Wilkin
<1
26
Camp Road
<1
106
Ambient Monitors
SO2 Maximum 1 hour averages (ppb)
Date
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
Community Centre 0 0 0 0 0 0 -
-
0
0
0
0
0
0
0
1
Primary School
0
4
2
6
5
4
-
17 -
-
14 16 13 1
4
2
5
Mt Ingoldsby
0
3
0
3
0
0
0
1
0
0
0
0
0
0
0
3
Scout Camp
0
4
0
3
1
0
0
0
-
-
-
-
-
-
-
Camp Wilkin
0
3
1
1
1
0
0
0
0
0
0
0
0
1
Camp Road
0
1
0
0
0
0
0
0
0
0
0
0
0
0
EPA Intervention Level
210
Alcoa Local Standard
170
0
0
23 0
1
1
0
1
1
-
1
1
13 12 -
10 3
9
11 9
4
26 7
9
2
3 129 1
0
0
0
1
0
1
0
0
-
-
-
6
1 104 5
0
0
1
1
0
0
1
3
2
2
26 0
0
0
0
0
0
0
4
0
0
0
3
1
1 106 0
0
15 0
0
0
0
1
0
0
0
0
1
ANGLESEA ENVIRONMENT REPORT FEBRUARY 2008
water
Water Storage
Barwon Water storage levels for the Geelong system at 30.5% capacity. Stage 4 restrictions apply with a
Daylight Savings exemption to permit limited residential garden watering.
Water Discharge
ML
February
Total
Ashponds (SP1)
122
257
Mine (SP4)
0
0
Water Monitoring
SP1
SP4
SP3
05/02/2008
Ashpond
Mine
Final
EPA limit
Lab Result
EPA limit
Lab Result
EPA limit
Lab Result
pH
4-10
8.2
3-9
-
5-9
6.8
Susp. Solids
100
<4
100
-
30
<4
Colour
50
5
50
-
50
6
Aluminium
10.00
0.20
10
-
5.50
0.07
Iron
10.00
0.17
0
-
4.00
0.25
Zinc
0.40
0.01
2.0
-
0.30
0.21
WATER WATER USAGE PER MONTH (ML)
Date
JAN
FEB MAR APR
Town Water
1.4
0.9
2.3
Bore Water
279
304
583
Mine Water
53
24
77
MAY JUNE JULY AUG
SEPT OCT
NOV
DEC
TOTAL
3 0 0 .0
3000
2 5 0 .0
2500
2 0 0 .0
2000
1 5 0 .0
1500
1 0 0 .0
1000
5 0 .0
0 .0
500
0
ANGLESEA ENVIRONMENT REPORT FEBRUARY 2008
soil research
Topsoil is considered a precious commodity at Alcoa
Anglesea. Whilst overburden is in abundance, the thin
sliver at the surface that we call topsoil is all we have
to rehabilitate the open cut mine. Or is it? Is
overburden just dirt or a valuable resource in disguise?
This summer, Vacation Student Ellen Palmer has been
out and about getting her hands dirty to answer that
very question. What are the physical and chemical
characteristics of the different layers within the soil
profile compared to our topsoil? Can we get plants to
grow in overburden?
To test this theory rye corn seedlings were planted in
two soils currently used in our mine rehabilitation
process: topsoil and subsoil; as well as overburden:
orange sandy clay, grey sand found near the coal
seam and a combo of orange sandy clay + orange
sand. The plants were separated into two watering
regimes to test if water availability also affected plant
growth. Half of the plants were watered every day
(thanks Wayne and Ian for the weekend watering!)
and the other half were watered every third day.
And the results….rye corn successfully grew in all of
the soil/overburden types. The plants grew the tallest
in the topsoil and grew the least in the orange sandy
clay. On average, the plants that were watered every
day irrespective of the overburden type grew slightly
more than the ones watered every three days.
So topsoil’s the best…but don’t chuck out the rest just
yet. The subsoil was the next best for plant growth
despite a higher sand content, less nutrients and less
organic matter compared to the topsoil. Sandy soils
are known to retain fewer nutrients compared to those
that contain large amounts of clay and organic matter.
Subsoil is the next layer immediately below the topsoil
in the natural soil profile. It is returned to the mine
rehabilitation at a depth of 100mm. However in the
gully systems the subsoil can reach depths of over one
metre. This presents an opportunity to save the ‘extra’
as a media in which to grow plants for future
rehabilitation activities.
The orange sandy clay was not very beneficial to plant
growth because its physical properties caused it to
cement together as it dried. Soil tests also found that it
had low amounts of Calcium which is an essential
plant nutrient. This meant water and roots found it
hard to move through the soil and the plants couldn’t
find enough water or nutrients to grow very tall. The
problems found in the orange sandy clay were
alleviated when combined with orange sand. Adding
more sand stopped the orange sandy clay from
cementing which helped water and roots to move
through the soil and allowed the plants to grow taller.
The plants in the grey sand found near the coal seam
actually grew better when they were watered less. It
was also found to contain the least amount of nutrients
of all the soil types. When it was watered every day the
few nutrients that were in it may have washed away
causing plants to grow less while the soil that was
watered every third day was able to keep some of the
nutrients allowing the plants to grow taller.
Whilst nothing can truly replace the diversity of the
natural seedbank within the topsoil, its availability is
limited. If another layer of the overburden can sustain
plant growth there is potential for areas to be
revegetated and rehabilitated. These results indicate
that by combining overburden with topsoil we may be
able to make the topsoil stretch further or by
combining different overburden types together we
have a soil capable of sustaining plant life.
ANIMALS OF THE ANGLESEA HEATH
GOLDEN ORB SPIDER (Nephila edulis)
Size:
Colour:
Distribution:
Habitat:
females body 2 - 4 cm, male 5mm
silvery-grey to plum coloured bodies and
brown-black, often yellow banded legs.
Males red-brown to brown in colour
Orb weaving spiders are found throughout
Australia
dry open forests and woodlands, coastal
sand dune shrubland and mangrove habitat
The Golden Orb Weavers build large, semi-permanent orb
webs. The strong silk has a golden sheen. These spiders
remain in their webs day and night and gain some protection
from bird attack by the presence of a ‘barrier network’ of
threads on one or both sides of the orb web.
Sometimes their strong webs manage to trap small birds or
bats, and the spider will wrap them and feed upon them.
More common prey items include flies, beetles, locusts,
wood moths and cicadas.
GOLDEN ORB SPIDER
ANGLESEA ENVIRONMENT REPORT FEBRUARY 2008
LAND
RAINFALL (mm)
Month
JAN
FEB MAR APR
2008 Rainfall
19.8
35.8
55.6
1968-2007 Average
44.5
42.7
87.2
MAY JUNE JULY AUG
SEPT OCT
NOV
DEC
TOTAL
7 00.00
130
120
6 00.00
110
100
5 00.00
90
80
4 00.00
70
60
3 00.00
50
40
2 00.00
30
20
1 00.00
10
0
0 .0 0
WATER
TOWN WATER USE (ML)
2000 2007 2008 JAN
FEB
Process
23.9
12.8
2.1
1.3
0.8
Amenity
11.6
1.5
0.2
0.1
0.1
MAR APR
MAY
JUN
JUL
AUG SEP
OCT
NOV
DEC
4 0 .0
2 .0
1 .8
3 5 .0
1 .6
3 0 .0
1 .4
2 5 .0
1 .2
1 .0
2 0 .0
0 .8
1 5 .0
0 .6
1 0 .0
0 .4
5 .0
0 .2
0 .0
0 .0
2 0 0 0
2 0 0 7
2 0 0 8
JA N
F E B
M A R
A P R
M A Y
JU N
JU L
A U G
S E P
O C T
N O V
D E C
AIR
GREENHOUSE GAS (GHG) TOTAL (Mt) & GHG EMISSION EFFICENCY (t/MWh)
GHG Mt
‹ GHG
t/MWh
1990
2000
2001
2002
2003
2004
2005
2006
2007
2008
1.42
1.23
1.27
1.50
1.45
1.47
1.31
1.49
1.40
1.40
1.34
1.24
1.19
1.21
1.21
1.20
1.21
1.20
1.18
1.16
2
1600000
1 .8
1400000
1 .6
1 .4
1 .2
1200000
1000000
1
800000
0 .8
600000
0 .6
400000
0 .4
0 .2
0
200000
0
ANGLESEA ENVIRONMENT REPORT FEBRUARY 2008
environmental improvement
Environmental Management Targets
February
2008 Total
Forecast
2008 Target
Reportable Environmental Incidents
0
0
0
0
Monthly EHS ASAT Audit Completion (%)
100
100
100
90
Air Emission Targets
February
2008 Total
Forecast
2008 Target
Ambient SO2 ( no. readings > 210ppb)
0
0
0
0
Stack SO2 (no. hrs > 100kg/min)
0
0
0
0
SO2 Load Reductions (lost MWh)
17
24.5
147
N/A
GHG Efficiency (t CO2 e/MWh)
1.16
1.16
1.16
1.20
Opacity (10 min av > 0.25g/m normal operation)
0
0
0
0
Water Targets
February
2008 Total
Forecast
2008 Target
Town Water (ML)
0.9
2.3
13.8
14.2
Bore Water (ML)
304
583
3498
2370
Waste Targets
February
2008 Total
Forecast
2008 Target
Waste to Landfill (t)
0.0
0.0
0.0
8.0
Solid Prescribed Waste to Landfill (t)
0.0
0.0
0.0
0.0
3
Mine Rehabilitation Targets
2008 Total
2008 Target
2008 Area to Clear (ha)
0.0
0.0
2008 Area to Rehabilitate (ha)
0.0
0.0
2007 Mine Rehabilitation Species Richness (%)
N/A
100
OUR ENVIRONMENT AND OUR EMPLOYEE
Ellen, welcome to Anglesea...you have spent your
summer holidays with us, what have you been up
to? I have been at Anglesea for a 12-week Vacation
Student Placement. I am currently conducting a research
project into the physical and chemical properties of the soils
within the mining area that may support plant growth. I have
also been working on the development of a database for the
information collected by the yearly botanical monitoring of
the mine rehabilitation areas.
What interested you in doing vacation work with
Alcoa? Alcoa has a good reputation. It’s also a local
organisation that offers work experience relevant to my field
of studies so I decided to apply.
What have you achieved during your work
experience at Alcoa? I’ve gained quality experience,
met new people, and applied the knowledge gained from my
studies.
What are your plans after your research project is
complete? Hopefully get another job in the same sort of
field. I want to get as much experience as possible.
...ELLEN PALMER
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