​The McArthur River Mine Environmental Monitoring Program is shaped to the environmental values of the south-western region of the Gulf of Carpentaria. Each value is supported by an MRM objective to protect the marine ecosystem, public health and safety, and maintenance of cultural and spiritual significance to the Indigenous people of the region.

We have a comprehensive range of programs that meet government regulations and are designed to evaluate the mine's performance. Results from these programs are used to improve environmental management strategies and identify any emerging or potential impacts.

Monitoring results are compared against baseline information along with national guidelines for water and soil quality set by the Australian and New Zealand Environment Conservation Council (ANZECC), and the National Environment Protection Measures (NEPM).

Environmental monitoring activities occur as part of MRM's commitments to the Australian and Territory regulatory authorities.

Water quality monitoring

Our site-based testing includes:

  • surface water quality in Barney Creek, Surprise Creek, Emu Creek  and McArthur River
  • groundwater quality and levels via monitoring bores installed around the mine site and Bing Bong Loading Facility
  • spatial and temporal evaluation of marine waters in the south western region of the Gulf of Carpentaria
  • potable water quality based on Australia Drinking Water Guidelines 2004
  • water levels in all key mine water storage facilities to check runoff rates and water losses
  • water meters on all major pipelines used to transfer water within the mine's system including supplying recycled water to the process plant and water trucks
  • water use to make sure all opportunities are taken to reuse mine water.

Tailings system monitoring

We carry out a regular and extensive range of tests to determine the content of the tailings, assess any incidence of seepage and to make sure the embankment wall, pipe and all infrastructure are in good working order. These tests are summarised in the following table.

MONITORING SCOPESCOPEFREQUENCYTESTING PARAMETERS
TailingsSamplingMonthlyOxidation characteristics
Piezometric levelsMonitoring boresEvery two monthsWater depth and pressure
GroundwaterObservation bores downstream of recovery boresEvery  three monthsWater quality Total volume of water pumped from recovery bores
Natural surface water quality

Samples from

McArthur River, Glyde River, Surprise Creek, Barney Creek, Emu  Creek tributaries

Weekly when flowing Water quality
Water storage pondsSamples from water containment pondsMonthlyWater quality
Decant pondInspection of water level and samplesDaily for levels Monthly for qualityDepth Water quality
EmbankmentInspect conditionMonthlySurface expression of seepage Erosion

Dust and soil

Monthly dust and annual soil samples are taken from sites around both the mine and Bing Bong loading facility. These check for any potential contamination from dust generated by the operations. Soil samples are taken annually at the same locations and are checked for zinc, lead, cadmium and copper.

Rechannelling rehabilitation

Revegetation of the constructed channels is considered by MRM to be a high priority necessary for the early establishment of aquatic and riparian ecosystem function.

 

The MRM Rehabilitation Monitoring Programme is designed to meet three key objectives:

  • Scientific assessment: To provide indicator data from rehabilitated sites across the MRM lease area, and a comparison against undisturbed reference sites
  • Continuous improvement: To provide results which allow refinement of rehabilitation techniques and an assessment of specific management options
  • Evaluation of ecosystem development: To quantify the condition of sites.

These objectives are designed to restore mined land to self-sustaining riparian and aquatic ecosystems, similar to those which existed prior to the rechannelling works.

Erosion and sediment control

Our monitoring ensures the bund walls around the open pit are secure and includes:

  • Visual observation of the bund walls to identify any cracking or gully erosion and of the topsoil stockpiles to check for wind and water erosion.
  • Inspection of sediment traps weekly during the wet season and monthly during the dry season and after all intense rainfall events.

River channelling—erosion and sediment monitoring

Our long-term monitoring of the Barney Creek and McArthur River channels is important to check their stability. Vegetation abundance and diversity will be based on species highlighted through previous baseline surveys prior to rechanneling.

Fish monitoring

The McArthur River is home to a number of fish species including the Freshwater Sawfish (Pristis pristis) listed as Critically Endangered on the IUCN Red List and afforded protection under the EPBC Act (1999)

Conducted by specialist consultants, our program monitors fish populations, seasonal pools and heavy metals in fish, mussels or crustaceans. We also use a tagging program to track fish movements which is supported by the local fishing community.

We have developed a specific action plan for the freshwater sawfish which includes:

  • the ecology and biology of the freshwater sawfish
  • a description of the existing environment
  • management actions to ensure the longevity of the freshwater sawfish populations
  • ongoing monitoring of the freshwater sawfish populations for the life of the mine
  • a community awareness and education program.

Bird monitoring

The monitoring program checks for any changes in the population of birds in the area surrounding the mine both upstream and downstream and compared with other local sites as well as providing information on the suite of birds found in the local area.

The banding of birds is also taking place on indicator species like the purple crowned fairy wren and buff sided robin.

In addition, annual migratory bird surveys are conducted around Port McArthur across an area that exceeds 100,000 hectares of shorebird and wetland bird habitat. The study area has been recognised as an important bird area for a number of species listed under the EPBC Act. Many of these species migrate to the Northern Hemisphere on the East Asian-Australasian migratory bird flyway.

The annual migratory bird program reports are presented to the Australian Government.

Annual Metals in Seawater, Sediment and Biota Monitoring

This program started in 1998 and measures:

  • water and sediment quality
  • any impact our operations might have on the sediment and water quality due to the storage and transport of concentrate from Bing Bong Loading Facility
  • elemental composition of seagrass and molluscs in relation to known characteristics of potential contaminants from the Bing Bong operations.

Improvements since have increased the number of survey samples sites and species of fish, crabs and biota sampled.

 

Annual Seagrass Survey

The annual seagrass monitoring program commenced in 1994.

The overarching aim of seagrass monitoring program is to determine whether any observed change in seagrass distribution at Bing Bong was likely to be naturally occurring (and widespread throughout the area) or otherwise

  • Identify and describe broadscale patterns in the seagrass assemblage structure occurring within the study area;
  • Identify and categorise the relative cover and/or abundance of seagrass;
  • Provide an assessment of spatial and temporal patterns in seagrass assemblages, relative to past monitoring results;
  • Provide an assessment and comparison of the seagrass assemblages in the broader region with those adjacent to the Bing Bong Loading Facility;
  • Identify any key changes in seagrass communities within the lease area and implications for future management of the site.

 Between 1994 and 2005 several surveys were conducted on seagrasses in the swing basin for the Bing Bong Loading Facility to determine the distribution of species in the study area. Since this time, seagrass surveys have been conducted by a specialist consultant as part of MRM's commitment to managing potential environmental risks around the Bing Bong Loading Facility. Sampling focuses on broad-scale distributions of seagrass within the Mineral lease in order to identify any shifts in seagrass patterns.