📋 Case Study

Norwegian Limestone Mine: Digital Twin for Sustainable Closure Planning

Regulatory requirement for 100-year water quality forecast post-closure; uncertainty in acid rock drainage (ARD) evolution

🏗️ Project Overview

Steinberg Mine Post-Production Transition

🎯 Challenge

Regulatory requirement for 100-year water quality forecast post-closure; uncertainty in acid rock drainage (ARD) evolution

🔧 Design Approach

Geochemical reaction twin (PHREEQC engine) coupled with hydrological flow model and long-term geochemical monitoring; validated against 15-year field leachate dataset

📐 Design Diagram

(PHREEQC)Hydrological Flow Model15-Year Field Leachate DatasetARD UncertaintyOutputsCoupled InterfacepH Forecast Uncertainty Band:±2σ @ 50-yr: pH 4.1–5.9Sulfate Load RMSE: ±12.4 mg/LRegulatory Horizon: 100 Years

AI-generated project design illustration

📐 Key Calculations

pH Forecast Uncertainty Band

±2σ at 50-yr horizon

Result: pH 4.1–5.9

Confirms compliance with pH ≥4.0 limit

Sulfate Load Projection Error

RMSE vs. Historical Data

Result: ±12.4 mg/L

Supports passive treatment design margin

📊 Results

Approved closure plan accepted by Norwegian Environment Agency on first submission; predicted ARD duration shortened by 22 years vs. conventional modeling; $4.2M saved in treatment infrastructure

💡 Lessons Learned

• •Mineralogical heterogeneity demands zonal geochemical parameterization
• •Long-term calibration requires decadal-scale sensor drift correction

✅ Key Takeaways

• 1Mineralogical heterogeneity demands zonal geochemical parameterization
• 2Long-term calibration requires decadal-scale sensor drift correction