Water Balance and Salt Load Analysis in Coal Mining

Services: Analysis, modelling and advisory services 

Location: Central-Western NSW 

Date: 2014

Image Credit: Unsplash

Our Scope 

Ulan Coal Mines (UCML) were operating under a regulated Salinity Offset Scheme (SOS) to manage net salt export from their operations. Due to shifts in source loads and site inventory, UCML required an updated understanding of how much salt was being exported via the Bobadeen Irrigation Scheme (BIS)—either through surface runoff or deep aquifer drainage. This was essential to ensure continued compliance with their Environmental Protection Licence (EPL) and to refine the size and scope of their SOS. 

Verterra’s Solution

Verterra conducted a desktop analysis of the water and salt balance for the Scheme. The project focused on identifying key irrigation management drivers that would maintain long-term resilience under varying salinity conditions.  

Project Highlights

• Crop Water Balance Modelling to assess water movement and usage 

• Salt Load Modelling to quantify salt accumulation and export 

• Analysis of key parameters including: 

  • Soil type 

  • Regional climate 

  • Crop species and salt tolerance 

  • Irrigation frequency and salinity 

  • Irrigation unit costs 

  • Management scenarios and their influence on system resilience 

Outcomes

Verterra’s modelling provided UCML with critical information on a variety of operational scenarios to understand their impact on both salt and water movement within the system. This enabled: 

• Design and maintenance of a resilient irrigation scheme tailored to site-specific salinity tolerances. 

• Quantified salt load exports through both runoff and deep drainage. 

• A scientifically sound foundation for calculating and implementing the Salinity Offset Scheme required under the mine’s EPL. 

This work helped ensure UCML could continue operating within regulatory frameworks while optimising on-site water reuse and reducing environmental risk.