Author: Mohsen Moogui
Date: July 2025
First Presented: GeoTails website

In the current mining landscape, regulators are rightfully scrutinous of any modifications to Tailings Storage Facilities (TSFs) that may exacerbate seepage or elevate environmental risks. At the same time, miners are under pressure to find cost-effective solutions for tailings storage that align with operational demands and tight budgets.

GeoTails Consulting recently supported Savannah Goldfields in navigating exactly this balance — addressing environmental concerns raised by Queensland’s Department of Environment, Science and Innovation (DESI) while unlocking an efficient and cost-effective solution for short-term tailings storage.

The Challenge

Savannah sought to raise the Internal Cell embankment at the Georgetown TSF by 3 metres to meet upcoming tailings storage requirements. The proposed raise made excellent operational sense — it would:
– Utilise local earthfill materials from an adjacent cutback,
– Minimise mobilisation costs, and
– Extend the facility’s storage life by approximately six months.

However, regulatory authorities raised concerns about potential worsening of seepage conditions and related environmental risks.

Our Approach

GeoTails developed and delivered a robust seepage assessment comparing the existing and proposed raised configurations using transient seepage modelling in SEEP/W. The assessment accounted for:
– Short operational life,
– Realistic decant pond positioning,
– Tailings beach slope behaviour, and
– Long-term water drawdown scenarios.

Crucially, our proposed design included:
– A low-permeability fill zone engineered to reduce seepage losses,
– A strategically placed decant pond over 100 m from the embankment, lowering the hydraulic gradient and reducing risk.

The Outcome

Our modelling clearly demonstrated that the raised embankment would not increase seepage — in fact, it would reduce seepage flux by over two-thirds compared to the existing condition. Key benefits included:

– Seepage rate at the toe reduced from ~1.6 L/m/day to <0.5 L/m/day
– Lower environmental risk and improved containment performance
– Cost-effective use of on-site materials, reducing construction costs
– A compliant, sustainable tailings solution aligned with future closure planning

Why It Matters

This project illustrates how GeoTails bridges technical rigour with practical value. By demonstrating improved environmental performance through smart geotechnical design, Savannah was able to move forward with confidence — delivering savings and securing short-term operational flexibility without compromising compliance.

Need Support for Your TSF Projects?

Whether you’re navigating regulatory requirements, planning cost-effective expansions, or optimising tailings deposition, GeoTails Consulting can help you find the right solution — grounded in engineering, tailored to operations, and aligned with the environment.

📩 Get in touch at Mohsenm@geotails.com.au or visit www.geotails.com.au