Environment

Rio Tinto Alcan Yarwun

Environmental performance

At Rio Tinto Alcan Yarwun, we reported 46 non-compliances against our Environmental Authority during 2014. This was a significant improvement following 89 non-compliances during 2013.

A key priority for 2014 was to reduce total suspended solids (TSS) by an average of 15 per cent across all discharge points. This target was achieved through a consistent and targeted campaign to improve drainage and reduce erosion and sediment mobilisation by undertaking the following activities:

  • cleaning out drains to remove sediment;
  • cleaning out dams and ponds to maximise storage capacity;
  • mulching to reduce surface flow and reduce sediment mobilisation;
  • re-aligning drainage to improve drainage through correct channels;
  • sheeting known problem areas with stones, mulch and groundcover;
  • hydromulching;
  • trialling various methods of revegetation and slope stabilisation;
  • revegetation of open areas and traffic reduction through these areas; and
  • continued trials with chemical and physical sediment suppressants.

The graph below illustrates the year on year improvement that has been made with regard to TSS. Despite the significant improvement, TSS levels remain outside of license requirements and as such reducing TSS across all discharge points will remain a key priority for 2015.

Total Suspended Solids (site average) during wet season

A significant number of non-compliances in 2013 were due to monitoring equipment integrity and inadequate training. All monitoring equipment has been audited and repaired or recalibrated where required and a revised training package has been rolled out to maintenance personnel to ensure equipment is operated and maintained correctly. Since this work has been completed, there have been no incidents regarding Total Suspended Particulates (TSP).

Emissions verification work continued throughout 2014 with sampling undertaken in high risk dust emission points and open path monitoring on precipitation tanks. The open path monitoring equipment enabled Rio Tinto Alcan Yarwun to provide data to the Air Emissions Verification Study as required by the Environmental Authority. The refinery is an active member of the Gladstone Air Network and will continue to support this project.

Monitoring in Port Curtis continued throughout 2014 with Rio Tinto Alcan Yarwun undertaking Receiving Environment Monitoring Programme (REMP) and contributing to the Port Curtis Integrated Monitoring Programme (PCIMP). The refinery is a member of the Gladstone Healthy Harbour Partnership and will continue to support this partnership.

Non-compliance events
20

Spills

15

TSS or pH limit exceeded

5

Procedural

2

Dust release

4

Other

Show Table

2013

2014

2014

Performance

2015

Environmental incidents (medium and above)

63

47

0

0

Non-compliances

89

46

52

17

Freshwater use (ML)

9,330

9,625

*

*

Freshwater use efficiency (kL/t alumina

3.82

3.91

*

*

Seawater use (ML)

21,818

24,863

*

*

+Sulphur dioxide emissions (t)

220.00
(11 breaches)

938.35
(2 breaches)

30 per cent reduction in breaches

No licence breaches

+Nitrogen dioxide emissions (t)

1,100

1,631

No licence breaches

No licence breaches

Waste recycled (t)

989

1,265.43

1,200

1,300

Land revegetation (ha)

26.1

26.1

All land requiring revegetation has been revegetated

All land requiring revegetation has been revegetated

Greenhouse gas emissions (t CO2-e)

1,567,751

1,786,948

Refer to efficiency target

Refer to efficiency target

Greenhouse gas efficiency (t CO2-e/t alumina)

0.642

0.6591

0.718

0.822

Bayer process energy efficiency (GJ)

24,455,700

27,200,716

Refer to efficiency target

Refer to efficiency target

Bayer process energy efficiency (GJ/t alumina)

9.17

11.6015

8.992

9.412

Environmental incidents (medium and above) are near-source confined incidents with either an immediate or short-term reversible impact.
Freshwater use includes all process water used for washing, steam generation and cooling.
Seawater use includes seawater used to neutralise the caustic in bauxite residue and acts as a pumping mechanism to transport the residue to the RMA where it is separated from the residue, treated and returned to the sea.
*No target set - refinery is currently in ramp up phase and targets will be established when operating at planned production levels
+Data is under review for the 2013 period

Design storage allowance for the Residue Management Area

The 2014 RMA wall raise project was successfully delivered two weeks ahead of schedule and the 2015 RMA wall raise detailed design plan was submitted and approved prior to completion of the 2014 project. This work positions the business well to deliver the 2015 project. Work will continue in 2015 around land use approvals for the RMA2 lot.

Spill prevention and clean up

With more than 40 per cent of non-compliances due to spills, spill prevention will be a key focus in 2015.

Case Studies

Non-compliance reductions achieved

An extensive improvement project was undertaken in 2014 to reduce non-compliance incidents by 30 per cent.
Read more