003 ECM_22828362_v1_Reference Document - OPW23 0189 · OPW26/0094

                  Project No. PG-10899                                                                                                        Page | 1
                  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




                                    ACID SULFATE SOIL MANAGEMENT PLAN (ASSMP)
                                                      PROPOSED RESIDENCE
                                                30 MOSSMAN COURT, NOOSA HEADS
                  Objective                            The objective of the ASSMP is to control any acid generation from
                                                       insitu ASS materials and to restrict to an acceptable level any
                                                       potential on-site and off-site environmental impacts. A further
                                                       objective is to manage earthworks activities and provide measures
                                                       to maintain water quality within the site and in adjacent areas.
                  Proposed                             It is understood that the proposed development is to comprise the
                  Development                          construction of a two storey residence with a basement.
                                                       Earthworks are envisaged to consist of cuts of up to 3m for the
                                                       basement.        A total volume of material to be disturbed is
                                                       approximately 900m3. Additional investigation and testing will be
                                                       required to confirm the results and recommendations of this
                                                       management plan.
                  Subsurface                           Mapping
                  Conditions                           The site is located in an area that is mapped on the Noosa Council
                                                       Acid Sulfate Soils Mapping as Disturbed Land likely to contain ASS.
                                                       ASS Investigation
                                                       Drilling and sampling encountered a reasonably consistent profile
                                                       of sand that:
                                                       • did not indicate any obvious ASS presence from a visual and
                                                             tactile perspective in the fill or the natural profile.
                                                       •     indicated that the upper level sands were not acid sulfate soils
                                                             and the lower level sands below 3.0m indicated a low level of
                                                             acid sulfate soil present.
                                                       •     had the highest liming rate required to neutralise the acidity of
                                                             4kg/m3 (based on laboratory testing of selected samples) for
                                                             the lower level sands.
                                                       •     The proposed excavations for the basement (up to 3.0m
                                                             depth)are not expected to disturb the acid sulfate soils but may
                                                             just indicate the acid sulfate strata.
                  Management                           To mitigate and manage potential adverse environmental impacts
                  Strategy                             during site construction operations, the following will be
                                                       undertaken:
                                                       • an ASS consultant should review the site earthworks schedule
                                                           and plan of operations;
                                                       •     adoption of appropriate erosion control measures to limit
                                                             sediment loss due to run-off from site works area;
                                                       •     where excavation below the water table, or if disturbance of
                                                             any silty sands is necessary, a materials handling and
                                                             management strategy and procedures for lime treatment of
                                                             any disturbed material will be required;
                                                       •     monitoring and treatment (if necessary) of waters in detention
                                                             basins to a level suitable for discharge into external waterways;
                                                             and
                                                       •     site supervision by approved persons and regular reporting to
                                                             the Project Engineer/Manager throughout the construction
                                                             phase.




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