Plumes Outfalls

Plume and outfall modelling involves the use of numerical models and field instrumentation to predict the mixing and broader interaction of pollutants discharged from a point source within a their receiving environment.

Licenses to discharge pollutants to waterways are issued on the basis of a sound understanding for the interactions and mixing of these discharge within the natural environment. BMT WBM use a range of analytically tools, covering both rear-field and fur-field environments, to assess the advection and disperse of pollutants and the chemical and biological interaction with the natural system.

Recent Relevant Projects

Olympic Dam Expansion Environmental Impact Study (SA)

BHP Billiton (BHPB) had proposed to expand its existing mining operations at Olympic Dam, South Australia to the extent of creating the largest open cut mine in the world.  Considerable volumes of fresh water were required to support this expansion and mine operation and as such BHPB proposed to build and operate a desalination plant at Whyalla, on the coast of Spencer Gulf, to deliver this water via pipeline to the mine.  BMT WBM undertook a wide range of modelling studies to assess the likely interaction of the brine return water discharge from the plant, especially with regard to any effects on the nearby Australian Giant Cuttlefish breeding habitats.  The work was internationally peer reviewed and involved computational fluid dynamics (CFD) modelling of the outfall and linkage of these predictions with three dimensional far field models of the entire Spencer Gulf.  The EIS was approved by State and Federal Government in October 2011.

Gladstone Pacific Nickel Environmental Impact Study (Queensland)

Gladstone Pacific Nickel proposed to build a nickel processing plant at Gladstone,Queensland.  As part of the process, a discharge of waste to Port Curtis waters was proposed.  BMT WBM undertook detailed diffuser modelling of the proposed outfall, together with supporting far field dispersion modelling.  Computational fluid dynamics (CFD) was used to deliver this modelling, and the EIS was approved in 2009. 

Evans River Sewage Outfall (NSW)

Disposal of municipal sewage via a riverine or estuarine outfall often requires detailed mixing zone and toxicity assessments.  BMT WBM was commissioned to investigate these for a proposed sewage outfall in the tidal portion of the Evans River, New South Wales.  Detailed diffuser modelling was undertaken to assess the likely mixing zone of the discharge under various outfall flow rate and tidal current flow conditions.  Following these works, and execution of far field (dispersion) modelling, an engineering solution was provided.