Attachment 4 - Geotech Report · MCU23/0030

                                                                                                                          Table C1 - Summary of ASS Laboratory Testing                                                                                                                Ref: 22500

                                                                                                                                                     Titratable
                                                                                                                                                                                             Chromium Reducible                                            NET
Location & Depth                                     pHF              AASS            pHFOX              PASS          Reaction           pH KCl      Actual                SKCl                                                  SNAS       ANC_bt                       Required Lime Rate
                          Soil Type                                                                                                                                                                Sulfur                                                 ACIDITY
       (m)                                                          liklihood1                        likelihood2                                     Acidity
                                                                                                                                                                                                                                                                                                   3
                                                   pH Unit                           pH Unit                             1 to 4           pH Unit   mole H+ / t              %S                 %S        mole H+ / t         mole H+ / t   mole H+ / t   mole H+ / t   kg CaCO3/t   kg CaCO3/m
         0.0-0.25                                     6.0                L               3.1               M                 4
         0.25-0.5                                     5.7                L               3.0               M                 4
                          SAND (Fill)
         0.5-0.75                                     4.8               M                2.8               H                 4               5.0          11               < 0.005            < 0.005           <3                 N/A         N/A            11           0.9           1.5
         0.75-1.0                                     5.4                L               3.0               M                 4
         1.0-1.25         Sandy Clay                  4.9               M                2.8               H                 4
         1.25-1.5         (Alluvium)                  5.3                L               2.0               H                 4
 BH1
         1.5-1.75                                     5.4                L               2.0               H                 4               4.8          15                0.023               0.21            130                N/A         N/A           145           11.5          19.5
         1.75-2.0                                     5.7                L               2.3               H                 4
         2.0-2.25                                     5.6                L               2.3               H                 4
         2.25-2.5                                     5.6                L               2.2               H                 4
         2.5-2.75         Silty SAND                  5.0               M                2.7               H                 4
         2.75-3.0         (Alluvium)                  5.6                L               2.3               H                 4               5.0          7.7               0.009               0.12            77                 N/A         N/A           84.7          6.7           11.4
         3.0-3.25                                     7.6                L               2.4               H                 4
         3.25-3.5                                     5.5                L               2.5               H                 4
         3.5-3.75                                     8.2                L               2.6               H                 4               5.9          2.7               0.007               0.076           48                 N/A         N/A           50.7          4.0           6.8
         3.75-4.0                                     5.3                L               1.9               H                 4
         0.0-0.25                                     5.5                L               2.7               H                 3
                       Silty SAND (Fill)
         0.25-0.5                                     5.6                L               3.0               M                 3
         0.5-0.75                                     5.8                L               3.1               M                 3               5.1          8.1              < 0.005            < 0.005           <3                 N/A         N/A            8.1          0.6           1.1
         0.75-1.0                                     5.8                L               3.3               M                 3
         1.0-1.25                                     5.8                L               3.2               M                 3
                          SAND (Fill)
         1.25-1.5                                     6.1                L               3.9               M                 3               5.5          4.4              < 0.005              0.005           3.3                N/A         N/A            7.7          0.6           1.0
 BH2     1.5-1.75                                     6.3                L               3.9               M                 3
         1.75-2.0                                     6.2                L               3.9               M                 3
         2.0-2.25                                     5.1                L               2.4               H                 4
         2.25-2.5                                     5.2                L               2.1               H                 4               4.8          22                0.006               0.068           42                 N/A         N/A            64           5.1           8.6
         2.5-2.75         Silty SAND                  5.1                L               2.5               H                 3
         2.75-3.0         (Alluvium)                  5.3                L               3.2               M                 4
         3.0-3.25                                     6.3                L               1.9               H                 4
         3.25-3.5                                     6.4                L               2.0               H                 4               5.6          4.3               0.018               0.17            110                N/A         N/A           114.3         9.0           15.4
          Notes:    1. Actual Acid Sulfate Soil (AASS) liklihood is indicated by Low (L & no shading)(pHF > 5). Medium (M & yellow shade)(pHF 5 ≤ pHF > 4) and High (H & red shade)(pHF ≤ 4).
                    2. Potential Acid Sulfate Soil (PASS) liklihood is indicated by Low (L & no shading, where pHFOX is > 4 and ∆ pH from pHF to pHFOX is < 2 pH units). Medium (M & yellow shade, where ∆ pH from pHF to pHFOX is ≥ 2 pH
                    units OR pHFOX is <4)) and High (H and red shade)(change from pHF to pHFOX is ≥2 pH units AND pHFOX is <3)
                    3. Reaction 1 = Nil to slight reaction, 2 = Moderate reaction, 3 = Strong reaction (persistant froth), 4 = Extreme reaction.
                    4. Shaded TAA & SCR results are those exceeding the QASSIT action levels of 18 mol H+/t or 0.03 %S (> 0.03%S Yellow; > 0.1%S Orange; > 1.0%S Red).
                    5. Net Acidity = TAA + CRS + SNAS (Excluding ANC.)
                    5. Required Lime Rate is calculated from the net Acid-Base Account (ANC has not been corroborated) with a factor of safety = 1.5 and bulk density of 1.7 t/m³. N/R = Not Required