Reference Document - Acid Sulfate Soil Report 11_2023- OPW23_0189 · OPW26/0094

                  Project No. PG-10899                                                                                                        Page | 3
                  November 2023
                  Ref: PG-10899, 2023-10-16, ASSMP VER 2
                  DD Sunnyside CD Sunnyside Pty Ltd – Acid Sulfate Soil Management Plan – Proposed Residence, 30 Mossman Court, Noosa Heads




                  Performance                          ASS
                  Indicators                           Chromium Suite testing carried out for validation of applied liming
                                                       rates will be deemed to be acceptable if the net acidity recorded
                                                       is 18 mol H+/t.

                                                       Water
                                                       Laboratory testing of retained water will be carried out for pH,
                                                       electrical conductivity (ED), iron (Fe), aluminium (Al), dissolved
                                                       oxygen and turbidity. Levels of these parameters considered
                                                       acceptable are as follows:

                                                       pH                              6.5 to 8.5 pH units
                                                       EC                              <1,500 S/cm
                                                       Fe                              <1,000 ug/L
                                                       Al                              <5.0 ug/L if pH <= 6.5 pH units
                                                                                       <100.0 ug/L if pH > 6.5 pH units
                                                       Turbidity                       <20NTU
                                                       Dissolved Oxygen                >80% saturated

                                                       Testing for the Fe and Al will only be necessary if the pH of the water
                                                       falls below pH 6.0.
                  Frequency/Timing                     ASS
                                                       The sampling and testing of any lime treated material will be
                                                       subject to QA testing, which will be repeated until satisfactory
                                                       results are obtained. Chromium Suite validation testing will be
                                                       carried out at a rate of 1 test/250m3 of treated spoil.

                                                       Water
                                                       The following monitoring frequency is recommended during
                                                       dewatering operations (if required):
                                                       • daily measurements of pH, dissolved oxygen (DO), turbidity and
                                                          suspended solids; and
                                                       •     weekly measurements of the full list of Performance Indicators
                                                             nominated above (if dewatering has been required).
                                                       If the results of monitoring prove consistent, the frequency of
                                                       monitoring may be reduced, subject to the approval of the ASS
                                                       Consultant.
                  Corrective Action                    ASS
                                                       If lime treatment of ASS is unsuccessful, whereby performance
                                                       targets are not being met as indicated by the QA and water quality
                                                       testing procedures:
                                                       • The earthworks schedule will be reassessed and action taken to
                                                            determine the problems causing the breach of standards.
                                                       •     If the problems are related to ineffective implementation of the
                                                             ASSMP, then the plan will be audited to ensure improved
                                                             implementation. Monitoring and testing will be increased to
                                                             ensure compliance with the established standards.
                                                       •     Any significant changes to the ASSMP will be subject to
                                                             discussions with and the approval of, the relevant regulatory
                                                             authorities.
                                                       Water
                                                       Compliance failures regarding specified performance criteria shall
                                                       be recorded including the date, time, nature of failure and actions
                                                       taken to rectify the situation. Monitoring results should be reviewed




Document Set ID: 22828362
Version: 1, Version Date: 26/02/2024