South32 Ltd. · ASX:S32

South32 — Technical Presentation (May 2021)

12 slides from South32's technical presentation, May 13, 2021

  1. Slide 1: Overview of Groundwater and Surface Water Investigations – Town of Patagonia

    Overview of Groundwater and Surface Water Investigations – Town of Patagonia Flood and Flow Committee May 13, 2021

  2. Slide 2: Hermosa hydrogeological investigations

    Hermosa hydrogeological investigations

  3. Slide 3: Where to find new Hermosa documents

    Where to find new Hermosa documents Website:www.south32.net/hermosa/documents Footnote SLIDE 3

  4. Slide 4: Where to find new Hermosa documents (cont.)

    Where to find new Hermosa documents (cont.) Footnote SLIDE 4

  5. Slide 5: Spring and Seep Catalog update

    Spring and Seep Catalog update  Water quality results extended through June sampling in 2020  Addition of 50 new sites within the Patagonia Mts.  Site summary pages all include potential impacts to groundwater contributions at the spring/seep from early dewatering  Site descriptions include date

  6. Slide 6: Springs and Seeps: Example Summary Sheet

    Springs and Seeps: Example Summary Sheet Sample site identification Observed water quality in the field Water quality components that are of concern Plants and wildlife identified at the site Photos showing the site during wet and dry seasons Footnote SLIDE 6

  7. Slide 7: Aquifer testing at Hermosa (examples)

    Aquifer testing at Hermosa (examples)  A total of 11 different aquifer tests have been conducted on various wells at Hermosa conducted from 2017 through 2019  Aquifer testing has been used to understand the range in permeability of the differing geologic materials (volcanic and sedimentary aquifer

  8. Slide 8: Groundwater measurements and model boundaries

    Groundwater measurements and model boundaries Town of Model Boundary Patagonia  Measured water levels indicate flow from Patagonia Mts. Red Mountain toward Sonoita Creek  Groundwater is recharged at high elevations and moves towards the surrounding valleys.  In some locations, springs have provid

  9. Slide 9: Conceptual geologic and groundwater flow model

    Conceptual geologic and groundwater flow model

  10. Slide 10: Numerical groundwater model calibration

    Numerical groundwater model calibration Steady State Calibration 5500 Residual Mean 0.235 5300 Absolute Residual Mean 19.30 Residual Std. Deviation 29.68 Sum of Squares 130400 5100 RMS Error 29.68 Number of Observations 148 Observed Heads (ft amsl) 4900 Range in Observations 1601 Scaled Residual Std

  11. Slide 11: Preliminary Impact Simulation for Exploration Dewatering

    Preliminary Impact Simulation for Exploration Dewatering Area of Simulated Groundwater Rise (Maximum 20 feet) Area of Deep Simulated Simulated Groundwater Declines discharge (Maximum 1,900 feet) approx. 3,270 gpm Cone of depression Area of focused beneath Minor Simulated Hermosa Groundwater Declines

  12. Slide 12: Questions? askhermosa@south32.net

    Questions? askhermosa@south32.net

South32 — Technical Presentation (May 2021) on 6ix