Development Application Part 2 - Environmental & Stormwater Management Plans · OPW11/0335

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 The pH screening tests can be used for preliminary identification of potential or actual ASS, using a combination
 of three trigger factors' as follows:


 (a)       The strength of the reaction with peroxide is a useful indicator but cannot be used alone.                              Organic
           matter and other soil constituents such as manganese oxides can also cause a reaction.
 (b)       A pHrox value at least one unit below pHF may indicate a potential acid sulfate soil (PASS). The greater
           the difference between the two measurements, the more indicative the value is of a PASS. The lower
           the final pHFOx value the better the indication of a positive result.
 (c)       If the pHFOX <3, and the other two conditions apply, then it strongly indicates a PASS. The more the
           pHrox drops below 3. the more positive the presence of sulphides.


 The results of the screening tests undertaken on samples recovered from the bores are given in Table 2,
 together with an indication of which (if any) trigger factors were noted.

                                         Table 2: Summary of Screening Test Results

        Sample                                                                                       Screening Test Indicators
                               M ater ia l
Bore     Depth                   V.--
                                                    Reaction            pHF        pHrox   Strong reaction
                                                                                                                 pHF-ptkox>1        pHrox<3
           (m)                                                      I          (           with peroxide
        0.0-0.25                    FBI              Medium             4.7         2.0                              3                 3
        0 . 25-0 . 5                Fill             Medium             4. 8        2.9                              3         !       3
        0.5-0.75                    Fill              Strong            4.6         1.4          3                   3                 3
        0.75-1.0           Fill and Silty Clay        Strong            5.5         1.2          3                   3                 3
 1      1.0-1.25       Silty Clay and Silty Sand It   Strong            5.4         1.7          3                   3                 3
        1.25-1.5                Silty Sand            Weak              5.6         2.3                              3                 3
        1.5.1.75                Silty Sand          Very Weak           5.2         1.9
        1.75-2.0                Silly Sand          Very Weak           5.0         2.8                              3                 3

        2.0.2.25                Silty Sand          Very Weak           49          2.8                              3                 3
        0.0-0.25                    Fill            Very Strong         6.5         2.7          3           I       3                 3

        0.25-0.5                    FBI            Very Strong          5.3         2.1          3                   3                 3
        0.5-0.75                    FBI            Vier y- Strong       5.1         1.5          3                   3                 3
        0.75-1.0           Fill and Silty Clay        Strong            5.3         1.7          3                   3                 3

 2      1 0-1.25       Silty Clay and Silty Sand      Strong            5.6         1.3          3                   3                 3
        1.25.1.5                Silly Sand           Medium             5.4         1.9                              3                 J

        1.5-1.75                Silty Sand           Medium             5.7         2.1                                        ^       J

        1.75-2.0                Silty Sand           Medium             5.4         1.8
        2.0-2.25               Silty Sand            Medium             5.1         1.8                      I       3                 3




 I Ahern C H , Ahem M.R., Powel B. Gwddekines for Sampling and Analysis of Lowland Acid Sutate Sods (ASS) in
 Queensland 1988
 Residential Devebpnenf                                                                                                    Page 6of10
 215- 219 David Low Way. Pcrcgian Beach
 Project No. 07160                                                                                                        18 June 2007