Reference Document - OPW23 0189

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