Executive Summary
This report evaluates excavation delineation outcomes for hydrocarbon-impacted soil using a Monte Carlo simulation framework. It compares a conventional lab-only sampling workflow against a Rapid Scan (RemScan) workflow integrated with the GXLab platform.
Across thousands of simulated plumes, the analysis shows that increasing vertical measurement density using low-marginal-cost Rapid Scan data materially reduces under-excavation risk. This reduction in missed contamination events dominates total project cost when the consequences of rework, delay, and regulatory exposure are moderate to high.
Key findings from the simulations
- Holding borehole locations constant but increasing vertical resolution reduced mean total remediation measurement cost by ~17–20 percent across low, medium, and high penalty scenarios.
- Modestly increasing borehole density while maintaining high vertical resolution reduced mean measurement cost by ~48–60 percent.
- In all scenarios, the RemScan workflow reduced the high-cost tail driven by under-excavation events, even when conservative assumptions were applied to measurement error.
- Once a core exists, dense vertical data becomes economically rational because marginal analysis cost is low relative to excavation and rework risk.
- Near-real-time integration with GXLab compounds value by shortening decision cycles and reducing stop-start excavation behaviour.
Table ES-1. Total cost per plume (simulation summary; currency in AUD million (1AUD approx. 1.4USD)
| Case | Penalty | Lab mean | RemScan mean | Lab median | RemScan median | Mean reduction |
| 1 | Low | 0.37 | 0.31 | 0.21 | 0.12 | 17.3% |
| 1 | Medium | 1.07 | 0.86 | 0.60 | 0.32 | 19.0% |
| 1 | High | 2.64 | 2.12 | 1.46 | 0.78 | 19.6% |
| 2 | Low | 0.55 | 0.28 | 0.30 | 0.16 | 48.0% |
| 2 | Medium | 1.59 | 0.68 | 0.87 | 0.19 | 57.0% |
| 2 | High | 3.95 | 1.59 | 2.15 | 0.21 | 59.8% |
Interpretation of the cost tiers: The simulations compute total cost as (over-excavation volume × $80/m³) + (under-excavation volume × penalty) + sampling/analysis costs. Under-excavation penalty is evaluated as Low=$200/m³, Medium=$600/m³, High=$1,500/m³. These tiers represent best-case through worst-case consequences when contamination is missed and rework is required.
GXLab platform integration value: The direct financial savings shown above do not fully capture the operational value of a fast feedback loop. With RemScan results uploaded into GXLab in near real time, excavation boundary updates and volume estimates can be produced immediately, enabling tighter decision cycles, fewer demobilisation/remobilisation events, and less idle time waiting on laboratory turnaround.
Download the free report below to find out more.