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REFERENCE DOCUMENT
OPW24/0098
NOOSA COUNCIL
25 SEPTEMBER 2024
GEOTECHNICAL INVESTIGATION REPORT
PTG/00259 – 0001 – Rev0
PREPARED FOR: SCG Consulting Engineers
Date 28 June 2024
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Page 2
PTG Consulting
ABN: 89 668 880 448
www.ptgconsulting.com.au
UNIQUE DOCUMENT IDENTIFICATION
Document Title: Geotechnical Investigation Report – 25 Wyuna Drive, Noosaville
Project Number: PTG/00259
Document ID: PTG/00259 – 0001 – Rev0 – Geotechnical Investigation
Client: SCG Consulting Engineers
Client Contact: -
OFFICE DETAILS
Location: Sunshine Coast
Address: 2/9-13 Matheson Street, Baringa, QLD, 4551
Telephone: 1300 023 181
Email: [email protected]
Web: www.ptgconsulting.com.au
REVISION DETAILS
Revision Number Date Comments
0 28/06/2024 Issue of final report
DOCUMENT APPROVAL
Author Reviewer
Luke Goodluck Sean Kelly
Geotechnical Engineer Senior Geotechnical Engineer
PTG/00259 – 25 Wyuna Drive, Noosaville Page 2 of 15 28 June 2024
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PTG Consulting
ABN: 89 668 880 448
www.ptgconsulting.com.au
TABLE OF CONTENTS
1. REPORT SCOPE ...................................................................................................................................... 4
2. PROJECT DESCRIPTION .......................................................................................................................... 4
3. SITE DESCRIPTION ................................................................................................................................. 4
4. REGIONAL GEOLOGY ............................................................................................................................. 5
5. FIELD INVESTIGATION ........................................................................................................................... 6
6. GEOTECHNICAL MODEL ........................................................................................................................ 7
7. LABORATORY TESTING AND RESULTS ................................................................................................... 7
8. ACID SULFATE SOILS COMMENTS ....................................................................................................... 10
9. GEOTECHNICAL COMMENTS ............................................................................................................... 10
10. SITE CLASSIFICATION AND SITE MOVEMENTS .................................................................................... 11
11. FOUNDATIONS .................................................................................................................................... 11
1.2.1 PILES ........................................................................................................................................... 11
12. LIMITATIONS ....................................................................................................................................... 12
TABLES
Table 1: Summary of Laboratory Test Results ........................................................................................................ 7
Table 2: pH and pHfox Screening Results ............................................................................................................... 8
Table 3: Summary of Chromium Suite Testing ..................................................................................................... 10
Table 4: Ultimate Pile Capacities for Bored and Driven Piles ............................................................................... 11
ATTACHMENTS
Appendix 1: Test Location Plan
Appendix 2: Borehole Log Report Sheets
Appendix 3: Laboratory Test Result Reports
PTG/00259 – 25 Wyuna Drive, Noosaville Page 3 of 15 28 June 2024
Page 4
PTG Consulting
ABN: 89 668 880 448
www.ptgconsulting.com.au
1. REPORT SCOPE
This report presents the results of the geotechnical investigation carried out by PTG Consulting (Formerly
Protest) for a proposed Residential development at 25 Wyuna Drive, Noosaville. The investigation was
commissioned by SCG Consulting Engineers.
The geotechnical investigation comprised a single borehole with Dynamic Cone Penetrometer (DCP) testing
adjacent to the borehole and laboratory testing of selected representative soil samples undertaken per Protest’s
proposal PTT/07959/Rev0, ‘AS1726:2017-Geotechnical Site Investigations’ and ‘AS1289-Methods of Soil Testing
for Engineering Purposes’.
This report includes a description of the fieldwork procedures, the results of the fieldwork and laboratory testing,
and reporting on the following:
• Site description including detailed bored logs, site images and marked site plan with approximate test
locations;
• Review of regional geology;
• Subsurface conditions, including groundwater (if encountered);
• Site classification and predicted ground surface movement (ys) per AS 2870-2011;
• Indicative allowable bearing pressures for high-level footings;
• Indicative temporary and permanent cut batter slopes;
• Indicative presence and severity of ASS; and
• Any other geotechnical issues identified that will need management (if any).
2. PROJECT DESCRIPTION
The client's information indicates that at the time of the investigation, there was an existing dwelling on the
property, and limited access to the site was available. It is planned that the site will be demolished at a later
time. The preliminary information provided by the client indicates that the proposed new works will consist of
a residential building with basements. Additionally, it is understood that the site is located within an acid
sulphate soil (ASS) hazard overlay. A preliminary investigation of one borehole was proposed, with an additional
site visit scheduled after the demolition.
3. SITE DESCRIPTION
The investigated site is located 25 Wyuna Drive, Noosaville and is identified as Lot 12 on N10576. The site is
bordered by residential houses to the west and east, Wyuna Drive to the south, and Weyba Creek to the north.
At the time of investigation, the site was comprised of a residential house, maintained lawns and gardens, and
mature trees scattered throughout. Figure 1 is a 10 April 2024 Nearmap view of the site and its surroundings.
Figure 2 shows general site conditions at the time of the investigation.
PTG/00259 – 25 Wyuna Drive, Noosaville Page 4 of 15 28 June 2024
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PTG Consulting
ABN: 89 668 880 448
www.ptgconsulting.com.au
Figure 1: Nearmap view, 10 April 2024 (Site extents shown in red)
Figure 2: Site photo – General site conditions
4. REGIONAL GEOLOGY
Reference to the Queensland Government’s 1:100,000 geology series available on the Queensland Geoscientific
database (QGD) indicates that the site is underlain by Pleistocene aged alluvium comprising of ‘sandy mud,
muddy sand, minor gravel, estuarine channels and banks’.
Figure 3 below shows the regional geology as available on the QGD platform.
PTG/00259 – 25 Wyuna Drive, Noosaville Page 5 of 15 28 June 2024
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PTG Consulting
ABN: 89 668 880 448
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Figure 3: Regional Geology (extracted from QGD)
5. FIELD INVESTIGATION
The fieldwork included drilling one (1) borehole to a termination depth of 6 m using a 4WD utility-mounted
drilling rig fitted with 100 mm diameter solid flight augers. A geotechnical logged the materials and collected
samples.
Disturbed samples of representative soil materials were collected from the boreholes for soil description,
classification, and subsequent laboratory testing. The disturbed samples were subjected to visual-tactile
description and classification, which are shown on the attached logs and described in accordance with
AS1726:2017.
DCP testing was undertaken adjacent to the borehole from the surface, and the number of blows to achieve
100 mm depth penetration was recorded per AS1289.6.3.2.
Soil consistency and relative density described on the borehole logs were inferred from the DCP results, tactile
assessment, and published correlations.
The approximate borehole location are shown on the test location plan attached in Drawing 1. The borehole
log report sheets are attached in Appendix 2.
PTG/00259 – 25 Wyuna Drive, Noosaville Page 6 of 15 28 June 2024
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PTG Consulting
ABN: 89 668 880 448
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6. GEOTECHNICAL MODEL
In summary, the soil profile encountered within the borehole comprised silty sand fill to 2.6 m depth overlying
natural silty sand to the termination depth of 6 m.
Dynamic Cone Penetrometer (DCP) testing indicated:
• The silty SAND varied in density from loose grading to dense with depth.
Groundwater seepage was encountered within the borehole at an estimated depth of 2.4 m. It should be noted
that groundwater levels can be perched and fluctuate seasonally and during and after heavy rainfall events.
Given this natural variability, it is prudent to assume that water levels can fluctuate.
7. LABORATORY TESTING AND RESULTS
NATA accredited laboratory testing was undertaken on selected representative soil samples recovered from the
boreholes in accordance with ‘AS1289-Methods of Soil Testing for Engineering Purposes’. The laboratory testing
aimed to determine typical soil behaviour characteristics for engineering assessment.
The laboratory testing comprised the following:
• Particle size distribution tests; and
• Atterberg Limit.
The Laboratory Test Result Reports are included in Appendix 3 and are summarised in the table below.
Table 1: Summary of Laboratory Test Results
Fines Sand Gravel
Borehole Depth (m) Material < 75μm 75μm – 2.36mm – LL (%) PL (%) PI (%) LS (%)
(%) 2.3mm (%) 63mm (%)
BH1 2.5 – 2.9 SAND 7 93 0 39 NP NP 0
Note: LL – Liquid Limit, PL – Plastic Limit, PI – Plasticity Index, LS – Linear Shrinkage, NP – Non Plastic
Additionally, Acid Sulphate sampling was undertaken per the ‘Guidelines for Sampling and Analysis of Lowland
Acid Sulphate Soils in Queensland 1988, QASSIT Appendix A’ by the Department of Natural Resources.
Testing included field pHf, pHFOX and reaction with hydrogen peroxide in order to arrive at a ‘positive field
sulphide identification’ for subsequent selection of samples for further chromium suite testing. Results of the
testing are attached in Appendix 3.
Using these guidelines:
• A measured pHf less than 4 indicates that oxidation of sulfides has probably occurred in the past indicating
that AASS could be present; and
• A strong reaction with peroxide, A pHfox at least one unit below the measured pHf and a pHfox (following
oxidation) of less than 3 strongly indicates PASS.
Table 1 and Figures 1 to 3 show the pH screening test results and indicates which results fell below the action
criteria (pink zones). The test results highlighted in Table 9 and identified with a red circle in Figures 4 to 6
indicate the samples which were selected for the chromium suite.
PTG/00259 – 25 Wyuna Drive, Noosaville Page 7 of 15 28 June 2024
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ptgi PTG Consulting ABN: 89 668 880 448 www.ptgconsulting.com.au Table 2: pH and pHfox Screening Results e e 6 7 Field pH (pH units) 11 Bore Depth (m) Material PH (feta) PH (fox) seni pH Change BH1 0.0-0.25 SAND 7.6 5.4 2 2.2 BH1 0.25 - 0.50 SAND 74 5.7 3 1.7 BH1 0.50-0.75 SAND 7.2 5.3 4 1.9 BH1 0.75 — 1.00 SAND 75 5.4 2 2.1 BH1 1.00 - 1.25 SAND 74 4.8 3 2.6 BH1 1.25 -1.50 SAND 8.6 6.9 3 1.7 BH1 1.50-1.75 SAND 8.9 74 3 1.5 BH1 1.75 — 2.00 SAND 75 2.3 4 5.2 BH1 2.00 — 2.25 SAND 74 2.9 4 45 BH1 2.25 — 2.50 SAND 7.1 2.5 4 4.6 BH1 2.50 — 2.75 SAND 6.9 2 4 4.9 BH1 2.75 — 3.00 SAND 6.7 2 4 4.7 BH1 3.00 — 3.25 SAND 7.2 2.4 4 4.8 BH1 3.25 -— 3.50 SAND 7.1 2.5 4 4.6 BH1 3.50- 3.75 SAND 7.2 2.5 4 4.7 BH1 3.75 — 4.00 SAND 7.2 2.5 4 4.7 BH1 4.00 - 4.25 SAND 7.2 2.6 4 4.6 BH1 4.25 -4.50 SAND 7.2 2.5 4 4.7 BH1 4.50-4.75 SAND 7.1 2.6 4 45 BH1 4.75 — 5.00 SAND 7.1 2.5 4 4.6 BH1 5.00 - 5.25 SAND 7.1 2.2 4 4.9 BH1 5.25-5.50 SAND 7.1 2.6 4 45 BH1 5.50-5.75 SAND 7.2 2.6 4 4.6 BH1 5.75 — 6.00 SAND 7.2 2.6 4 4.6 Field pH measurements 0 0.5 e e 1 © £ e € 1.5 e ov a 2 e ‘ 2.5 o 12 13 14 Figure 4: Field pH test results PTG/00259 — 25 Wyuna Drive, Noosaville Page 8 of 15 28 June 2024
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pH(fox) measurements
0
0.5
1
Depth (m)
1.5
2
2.5
3
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
pH(fox) (pH units)
Figure 5: Field pHfox test results
Change in pH following oxidation
0
0.5
1
Depth (m)
1.5
2
2.5
3
0 1 2 3 4 5 6 7
pH(fox) (pH units)
Figure 6: Change in pHfox following oxidation
Chromium suite testing was undertaken on selected samples by a NATA accredited laboratory in accordance
with the ‘Queensland Acid Sulfate Soils Technical Manual, Soil Management Guidelines v4.0, 2014’. The action
criteria for existing plus potential acidity calculated in units of percent-sulfur equivalents (e.g. s-TAA + s-SNAS +
SCR in % S units), is 0.03%S for a course texture sand and 0.1%S for a fine texture clay in excavations under 1000
tonnes. The results of the chromium testing are attached in Appendix 3 and are summarised in Table 3 below.
PTG/00259 – 25 Wyuna Drive, Noosaville Page 9 of 15 28 June 2024
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PTG Consulting
ABN: 89 668 880 448
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Table 3: Summary of Chromium Suite Testing
Actual Potential Acid Existing plus
Borehole
Depth (m) Material Acidity Acidity Neutralising Potential Acidity
ID
(% pyrite S) (%S) Capacity (%S) (%S)
BH1 1.75 – 2.0 SAND 0.007 0.070 N/A 0.08
BH1 2.75 – 3.0 SAND 0.011 0.240 N/A 0.25
BH1 2.75 – 4.0 SAND 0.006 0.050 N/A 0.06
BH1 4.75 – 5.0 SAND 0.006 0.063 N/A 0.07
8. PRELIMINARY ACID SULFATE SOILS COMMENTS
The pH and Chromium Reducible Sulfur test results indicate the presence of Potential Acid Sulfate Soils. This
section outlines preliminary treatment advice however the following further work will be required to comply
with the National Acid Sulfate Soils Guidance – National acid sulfate soils sampling and identification methods
manual (June, 2018) as referenced by the Noosa Shire Council Acid Sulfate Soil overlay code:
For excavations between 501 m3 and 1000 m3 below RL 5 m AHD – drill an additional three boreholes to 1 m
below the lowest cut depth/level, sample and test.
An Acid Sulfate Soil Management Plan will be required as the preliminary testing has indicated test results which
breach the ‘action criteria’ in accordance with the information set out in the Queensland Acid Sulfate Soil
Technical Manual – Soil Management Guidelines Version 5.1, noting that less than 1000 t of sand based soils will
be excavated below RL 5 m AHD.
Due to the likely disturbance of Acid Sulfate Soils (ASS), it is imperative to treat the soils to mitigate the risk of
oxidation. This prevents pH reduction that could lead to acidic conditions, potentially harming the environment,
as well as buried steel and concrete.
For the management of ASS, 'Ag' Lime is recommended as the optimal neutralizing agent. It maintains a mildly
alkaline pH range of 8.5 to 9 and has low solubility, making it easy to handle without any significant operational
issues. 'Ag Lime' is essentially calcium carbonate derived from finely ground and sieved limestone.
The indicative/preliminary recommended liming rates are as follows:
• 3.6 kg of lime per ton for on-site fill treatment; and
• 12 kg of lime per ton for natural sandy soils.
It is advisable to use 'Ag Lime' with a purity of 95% or higher whenever possible. All lime treatment rates to be
confirmed/finalised by further testing once carried out.
9. GEOTECHNICAL COMMENTS
The geotechnical comments in this report are based on factual information collected during the fieldwork,
common practice, local experience and published literature however are fundamentally opinions.
Based on the ground conditions, it is likely that the most suitable foundation system for the buildings would
comprise bored and screw piers.
PTG/00259 – 25 Wyuna Drive, Noosaville Page 10 of 15 28 June 2024
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PTG Consulting
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10. SITE CLASSIFICATION AND SITE MOVEMENTS
For information purposes, the empirical method described in ‘AS2870-2011 Residential slabs and footings’ was
used to calculate the characteristic surface movement (ys) (ie. site reactivity) due to variation in normal seasonal
moisture conditions and climatic effects, and subsequent site classification.
In strict accordance with AS2870, the site is classified at the location of BH1 as Class ‘P’ due to:
• The presence of uncontrolled fill; and
• Abnormal moisture conditions as per section 2.1.3(e) caused by:
o Removal of an existing building or structure likely to have significantly modified the soil
moisture conditions under the footprint of the footing system of the building per section
1.3.3(a)
o Presence of trees on the building site or adjacent site as per section 1.3.3(c);
o The bearing strength is less than 50 kPa as per section 2.4.5
Due to the site Class ‘P’ the footing and slab system will need to be engineer designed.
Based on the laboratory test results and the empirical methods described in Section 2.3 of AS2870, the
calculated surface movement (ys) at the borehole locations in response to normal seasonal soil suction and
additional movement due to trees (yt) is expected to be between 0 mm and 20 mm which is consistent with a
Class S classification.
The indicated surface movement is based on a zero-crack depth factor, soil suction (∆u) of 1.2 pF and depth of
suction (Hs) of 1.5 m as the site is in a ‘Alpine/Wet Coastal’ climate. It should be noted that the design for the
footing system for tree-induced differential, centre heave, mound height (ym), is equal to 0.7ys + yt.
11. FOUNDATIONS
Bored/screwed foundations are considered suitable for the proposed development, though bored piles might
have constructability issues with collapse and water ingress.
All footing excavations should be inspected by Protest to confirm that bearing pressures have been achieved,
and footings are clean and free from loose and/or water softened materials.
1.2.1 PILES
Bored piles can be designed using the ultimate skin friction and base bearing capacities given in Table 4 below.
Piles should be founded a minimum of two pile diameters into the nominated strata and have a minimum pile
length of four times the pile diameter. The upper 1 m of pile length should be ignored due to pile load
development and shrink swell effects. Settlement of properly designed and constructed footings should be less
than 1% to 2% of the pile diameter. Piles should be designed using ‘AS 2159-2009: Piling - Design and
installation’ and including the recommendations contained in Appendix G of AS 2870 – 2011.
Table 4: Ultimate Pile Capacities for Bored and Driven Piles
Ultimate Skin Friction
Soil Type Ultimate Base Bearing (kPa)
(kPa)
Medium Dense natural SAND NA 600
Dense natural SAND NA 900
Notes: *Assuming pile is founded to a minimum depth of 1.5 m, NA – Not applicable
Screw piers could be designed for an ultimate end bearing of 550 kPa founding into the medium dense sand.
Specialist piling contractors should be consulted when selecting and installing piles.
To calculate the design geotechnical strength (Rd,g), the ultimate geotechnical strength should be multiplied by
a suitable geotechnical strength reduction factor (фg) as per Section 4 of AS 2159–2009. Typically, for residential
development with limited site investigation and design using empirical values, the assessed risk rating would be
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PTG Consulting
ABN: 89 668 880 448
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high and a фg value of 0.40 would apply. Where an allowable bearing pressure is required, a factor of safety of
3 should be adopted.
The above parameters are only suitable where the excavation of piled foundations are supervised and at a
minimum inspected by a suitably qualified geotechnical engineer to confirm the founding conditions and
materials encountered in the side walls.
The design of piled foundations should be undertaken in accordance with:
• AS2159-2009: Piling - Design and installation;
• Any other relevant design standards (Australian or international); and
• Engineering Principles.
The piled foundation design should also consider:
• Piles should be founded a minimum of two pile diameters into the nominated strata and have a minimum
pile length of four times the pile diameter;
• The upper 1 m of pile length should be ignored due to pile load development and shrink swell effects; and
• Settlement of properly designed and constructed footings should be less than 1% to 2% of the pile diameter.
To calculate the design geotechnical strength (Rd,g), the ultimate geotechnical strength should be multiplied by
a suitable geotechnical strength reduction factor (фg) as per Section 4 of AS 2159–2009. The geotechnical
strength reduction factor (фg) is based on:
• фgb = The basic geotechnical strength reduction factor, calculated using a risk assessment procedure;
• фtf = Intrinsic testing factor, based on the type of pile testing adopted; and
• K = The testing benefit factor, based on a percentage of the piles that are tested.
Typically, where no pile testing is undertaken and the piles have a low redundancy, the assessed risk rating would
be high and a фg value of 0.45 would apply. Where an allowable bearing pressure is required, a factor of safety
of 2.5 can be adopted. Specialist piling contractors should be consulted when selecting and installing piles.
12. LIMITATIONS
It should be noted that the test sites simply give a representation of what the soil profile is expected to be across
the entirety of the site. However, it is possible for the soil profile to differ at other locations within the site and
due to this Protest Engineering requires notification of any varying conditions that are found during construction
as it may alter the assumptions and models adopted within this report.
PTG/00259 – 25 Wyuna Drive, Noosaville Page 12 of 15 28 June 2024
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Appendix 1
TEST LOCATION PLAN
PTG/00259 – 25 Wyuna Drive, Noosaville 28 June 2024
Page 14
Site locality
Legend
Approximate borehole location
and number
BH1
Client: SCG Engineering
Site: 25 Wyuna Dr
Noosaville, QLD, 4556
Title: Test Location Plan
Test Location Plan
Date: Drawn: Checked:
21/06/2024 LG SK
Project: Drawing No: Revision
PTG/00259
1 0
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PTG Consulting
ABN: 89 668 880 448
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Appendix 2
BOREHOLE LOGS
PTG/00259 – 25 Wyuna Drive, Noosaville 28 June 2024
Page 16
BOREHOLE BH1
CLIENT: SCG Engineering DATE: 04/06/2024
PROJECT: Geotechnical Investigation EASTING:
LOCATION: 25 Wyuna Drive, Noosaville NORTHING:
PROJECT NUMBER: PTG/00259 SURFACE ELEV:
DRILLER: Protest Engineering RIG: GT-10 LOGGED: ZK CHECKED: SK
Sampling & Testing
Drilling Method
Layer Depths
Graphic Log
Strength Dynamic
Material Description (Consistency, Results & Penetrometer Test
Type (blows per 100 mm)
Comments
Water
Relative Density,
RL Depth Rock Strength)
(m) (m) 5 10 15 20
FILL - SAND, yellow brown, fine to medium grained, loose, moist 0
0 1
D 2
0.25 1
Loose D 2
1
0.5
1
D 1
0.7 grey, fine, medium dense, moist 0.75 2
Medium Dense
D 8
1 0.9 dense 6
1
Dense 10
D 10
1.2 medium dense 1.25 9
D 7
7
1.5
3
D 3
1.75 4
D 5
Medium Dense
2 8
2
3
D 6
2.25 3
D 3
3
2.5
3
2.6 SAND, grey black, fine to medium grained, dense, moist D 7
Dense 2.75 11
D 12
3
3
D
3.25
D
3.5
D
3.75
D
4
4
D
4.25
D
PTG - BOREHOLE REPORT (NORMAL) PTG00258BHLOGS.GPJ DRAFT.GDT 21/6/24
4.5
D
4.75
D
5
5
D
5.25
D
5.5
D
5.75
D
6
6
Bore terminated at 6 m.
Target depth achieved.
Remarks:
ASS sampling at 0.25 m intervals from 0.25 m to 6 m depth.
Page 17
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Appendix 3
LABORATORY TESTING
PTG/00259 – 25 Wyuna Drive, Noosaville 28 June 2024
Page 18
Certificate of Analysis
NATA Accredited
Accreditation Number 1261
Protest Engineering Pty Ltd Site Number 20794
159 Coronation Drive Accredited for compliance with ISO/IEC 17025 – Testing
NATA is a signatory to the ILAC Mutual Recognition
Milton Arrangement for the mutual recognition of the
equivalence of testing, medical testing, calibration,
Qld 4064 inspection, proficiency testing scheme providers and
reference materials producers reports and certificates.
Attention: Luke Goodluck
Report 1104946-S
Project name 25 WYUNA DRIVE
Project ID PTG/00259
Received Date Jun 06, 2024
Client Sample ID BH1_0.0-0.25 BH1_0.25-0.5 BH1_0.5-0.75 BH1_0.75-1.0
Sample Matrix Soil Soil Soil Soil
Eurofins Sample No. B24-Jn0011894 B24-Jn0011895 B24-Jn0011896 B24-Jn0011897
Date Sampled Not ProvidedI12 Not ProvidedI12 Not ProvidedI12 Not ProvidedI12
Test/Reference LOR Unit
Acid Sulfate Soils Field pH Test
pH-F (Field pH test)* 0.1 pH Units 7.6 7.4 7.2 7.5
pH-FOX (Field pH Peroxide test)* 0.1 pH Units 5.4 5.7 5.3 5.4
Reaction Ratings*S05 0 comment 2.0 3.0 4.0 2.0
Client Sample ID BH1_1.0-.125 BH1_1.25-1.5 BH1_1.5-1.75 BH1_1.75-2.0
Sample Matrix Soil Soil Soil Soil
Eurofins Sample No. B24-Jn0011898 B24-Jn0011899 B24-Jn0011900 B24-Jn0011901
Date Sampled Not ProvidedI12 Not ProvidedI12 Not ProvidedI12 Not ProvidedI12
Test/Reference LOR Unit
Acid Sulfate Soils Field pH Test
pH-F (Field pH test)* 0.1 pH Units 7.4 8.6 8.9 7.5
pH-FOX (Field pH Peroxide test)* 0.1 pH Units 4.8 6.9 7.4 2.3
Reaction Ratings*S05 0 comment 3.0 3.0 3.0 4.0
Client Sample ID BH1_2.0-2.25 BH1_2.25-2.5 BH1_2.5-2.75 BH1_2.75-3.0
Sample Matrix Soil Soil Soil Soil
Eurofins Sample No. B24-Jn0011902 B24-Jn0011903 B24-Jn0011904 B24-Jn0011905
Date Sampled Not ProvidedI12 Not ProvidedI12 Not ProvidedI12 Not ProvidedI12
Test/Reference LOR Unit
Acid Sulfate Soils Field pH Test
pH-F (Field pH test)* 0.1 pH Units 7.4 7.1 6.9 6.7
pH-FOX (Field pH Peroxide test)* 0.1 pH Units 2.9 2.5 2.0 2.0
Reaction Ratings*S05 0 comment 4.0 4.0 4.0 4.0
Eurofins Environment Testing 1/21 Smallwood Place, Murarrie, QLD, Australia, 4172 Page 1 of 8
Date Reported: Jun 07, 2024 ABN : 50 005 085 521 Telephone: +61 7 3902 4600 Report Number: 1104946-S
Page 19
Client Sample ID BH1_3.0-3.25 BH1_3.25-3.5 BH1_3.5-3.75 BH1_3.75-4.0
Sample Matrix Soil Soil Soil Soil
Eurofins Sample No. B24-Jn0011906 B24-Jn0011907 B24-Jn0011908 B24-Jn0011909
Date Sampled Not ProvidedI12 Not ProvidedI12 Not ProvidedI12 Not ProvidedI12
Test/Reference LOR Unit
Acid Sulfate Soils Field pH Test
pH-F (Field pH test)* 0.1 pH Units 7.2 7.1 7.2 7.2
pH-FOX (Field pH Peroxide test)* 0.1 pH Units 2.4 2.5 2.5 2.5
Reaction Ratings*S05 0 comment 4.0 4.0 4.0 4.0
Client Sample ID BH1_4.0-4.25 BH1_4.25-4.5 BH1_4.5-4.75 BH1_4.75-5.0
Sample Matrix Soil Soil Soil Soil
Eurofins Sample No. B24-Jn0011910 B24-Jn0011911 B24-Jn0011912 B24-Jn0011913
Date Sampled Not ProvidedI12 Not ProvidedI12 Not ProvidedI12 Not ProvidedI12
Test/Reference LOR Unit
Acid Sulfate Soils Field pH Test
pH-F (Field pH test)* 0.1 pH Units 7.3 7.2 7.2 7.1
pH-FOX (Field pH Peroxide test)* 0.1 pH Units 2.6 2.5 2.6 2.6
Reaction Ratings*S05 0 comment 4.0 4.0 4.0 4.0
Client Sample ID BH1_5.0-5.25 BH1_5.25-5.5 BH1_5.5-5.75 BH1_5.75-6.0
Sample Matrix Soil Soil Soil Soil
Eurofins Sample No. B24-Jn0011914 B24-Jn0011915 B24-Jn0011916 B24-Jn0011917
Date Sampled Not ProvidedI12 Not ProvidedI12 Not ProvidedI12 Not ProvidedI12
Test/Reference LOR Unit
Acid Sulfate Soils Field pH Test
pH-F (Field pH test)* 0.1 pH Units 7.1 7.1 7.1 7.2
pH-FOX (Field pH Peroxide test)* 0.1 pH Units 2.5 2.2 2.6 2.6
Reaction Ratings*S05 0 comment 4.0 4.0 4.0 4.0
Eurofins Environment Testing 1/21 Smallwood Place, Murarrie, QLD, Australia, 4172 Page 2 of 8
Date Reported: Jun 07, 2024 ABN : 50 005 085 521 Telephone: +61 7 3902 4600 Report Number: 1104946-S
Page 20
Certificate of Analysis
NATA Accredited
Accreditation Number 1261
Protest Engineering Pty Ltd Site Number 20794 & 2780
159 Coronation Drive Accredited for compliance with ISO/IEC 17025 – Testing
NATA is a signatory to the ILAC Mutual Recognition
Milton Arrangement for the mutual recognition of the
equivalence of testing, medical testing, calibration,
Qld 4064 inspection, proficiency testing scheme providers and
reference materials producers reports and certificates.
Attention: Luke Goodluck
Report 1108357-S
Project name 25 WYUNA DRIVE
Project ID PTG/00259
Received Date Jun 12, 2024
Client Sample ID BH1_1.75-2.0 BH1_2.75-3.0 BH1_3.75-4.0 BH1_4.75-5.0
Sample Matrix Soil Soil Soil Soil
Eurofins Sample No. B24-Jn0039179 B24-Jn0039180 B24-Jn0039181 B24-Jn0039182
Date Sampled Not ProvidedI12 Not ProvidedI12 Not ProvidedI12 Not ProvidedI12
Test/Reference LOR Unit
Extraneous Material
<2mm Fraction 0.005 g 54 74 70 56
>2mm Fraction 0.005 g < 0.005 < 0.005 < 0.005 < 0.005
Analysed Material 0.1 % 100 100 100 100
Extraneous Material 0.1 % < 0.1 < 0.1 < 0.1 < 0.1
Net Acidity (Excluding ANC)
s-CRS Suite - Net Acidity - NASSG (Excluding ANC) 0.02 %S 0.08 0.25 0.06 0.07
CRS Suite - Net Acidity - NASSG (Excluding ANC) 10 mol H+/t 48 160 35 43
CRS Suite - Liming Rate - NASSG (Excluding ANC) 1 kg CaCO3/t 3.6 12 2.6 3.3
Actual Acidity (NLM-3.2)
pH-KCL (NLM-3.1) 0.1 pH Units 5.8 5.4 5.5 5.5
Titratable Actual Acidity (NLM-3.2) 2 mol H+/t 4.3 6.9 3.7 3.9
Titratable Actual Acidity (NLM-3.2) 0.003 % pyrite S 0.007 0.011 0.006 0.006
Potential Acidity - Chromium Reducible Sulfur
Chromium Reducible Sulfur (s-SCr) (NLM-2.1)S04 0.005 %S 0.070 0.24 0.050 0.063
Chromium Reducible Sulfur (a-SCr) (NLM-2.1) 3 mol H+/t 43 150 31 39
Extractable Sulfur
Sulfur - KCl Extractable 0.005 %S N/A N/A N/A N/A
HCl Extractable Sulfur 0.005 %S N/A N/A N/A N/A
Retained Acidity (S-NAS)
Net Acid soluble sulfur (SNAS) NLM-4.1 0.005 %S N/A N/A N/A N/A
Net Acid soluble sulfur (s-SNAS) NLM-4.1S02 0.005 %S N/A N/A N/A N/A
Net Acid soluble sulfur (a-SNAS) NLM-4.1 2 mol H+/t N/A N/A N/A N/A
HCl Extractable Sulfur Correction Factor 1 factor 2.0 2.0 2.0 2.0
Acid Neutralising Capacity (ANCbt)
Acid Neutralising Capacity - (ANCbt) (NLM-5.2) 0.01 % CaCO3 N/A N/A N/A N/A
Acid Neutralising Capacity - (s-ANCbt) (NLM-5.2)S03 0.02 %S N/A N/A N/A N/A
Acid Neutralising Capacity - (a-ANCbt) (NLM-5.2) 2 mol H+/t N/A N/A N/A N/A
ANC Fineness Factor factor 1.5 1.5 1.5 1.5
Net Acidity (Including ANC)
s-CRS Suite - Net Acidity - NASSG (including ANC) 0.02 %S 0.08 0.25 0.06 0.07
CRS Suite - Net Acidity - NASSG (Including ANC) 10 mol H+/t 48 160 35 43
CRS Suite - Liming Rate - NASSG (Including ANC)S01 1 kg CaCO3/t 3.6 12 2.6 3.3
Sample Properties
% Moisture 1 % 20 19 19 19
Eurofins Environment Testing 1/21 Smallwood Place, Murarrie, QLD, Australia, 4172 Page 1 of 7
Date Reported: Jun 19, 2024 ABN : 50 005 085 521 Telephone: +61 7 3902 4600 Report Number: 1108357-S
Page 21
Protest Engineering
ABN: 26 602 913 673
www.protestengineering.com
Material Quality Report
Client : PTG CONSULTING PTY LTD Report Number : SR/PTP/14152 - 8/1
Client Address : level 3/159 Coronation Drive, Milton, 4064, QLD Report Date : 13/06/2024
Project Name : Lab Testing - Sunshine Coast Test Request : PTG/00259
Project Number : PTP/14152
Page 1 of 1
Location : Baringa
Test Methods : AS1289.3.6.1, AS1289.2.1.1,AS1289.1.1,
Material Description Sand
Sample Number : S/255424 Sampling Method : As Received
Date Tested : 12/06/2024 Date Sampled : 4/06/2024
Material Source : Insitu Location 1 : BH1
Material Type : Foundation Location 2 : 2.5 - 2.9 m
Lot Number : - Location 3 : -
PSD Specification Number : N/A Location 4 : -
ATT Specification Number : N/A
AS Sieve Size (mm) : Percent Passing (%) : Specification Limits : Particle Size Distribution Graph
100
75.0
63.0 90
53.0
80
37.5
26.5 70
Percentage Passing (%)
19.0
60
16
13.2 50
9.5
40
6.7
4.75 100 30
2.36 100
20
1.18 100
0.600 99 10
0.425 96
0
0.300 76
0.3mm
0.6mm
0.15mm
1.18mm
2.36mm
4.75mm
0.425mm
0.075mm
0.150 12
0.075 7 Sieve Size (mm)
Atterberg Limits : Test Methods: Test Results : Specification Limits : Test Results : Specifications Limits :
Liquid Limit (%) : AS1289.3.9.2 39 WPI : Q252
Plastic Limit (%) : AS1289.3.2.1 Non Plastic
Plasticity Index (%) : AS1289.3.3.2 Non Plastic
Linear Shrinkage (%) : AS1289.3.4.1 0 Linear Shrinkage Mould Length (mm): 124
Notes : History of Sample: Oven Dried, Method of Preparation: Dry Sieved, Linear Shrinkage: Nil Occurred
Pre-treatment (CAn) : -
Pre-treatment (Wn) : -
Mass Retained (R) : -
Remarks : -
Note: The results contained in this report relate only to the item/s that were tested/sampled APPROVED SIGNATORY
Accredited for Compliance with ISO/ IEC 17025 - Testing
Protest Engineering (Sunshine Coast) Accreditation Number - 20499
Base Laboratory Site Number - 24490 - Sunshine Coast
Base Laboratory Address - 2/9-13 Matheson St, Baringa, QLD 4551 Liam Manfield - Signatory
Document Number : RF9 Date : 30/05/2024
Page 22
ADG Consulting Pty Ltd All Correspondence
ACN: 630 555 225 PO Box 6405
ABN: 98 630 555 225 Yatala DC QLD 4207
P 07 3801 1564
E [email protected]
W adgconsulting.com.au
REFERENCE DOCUMENT
OPW24/0098
NOOSA COUNCIL
25 SEPTEMBER 2024
Dewatering Management Plan
Proposed Residential Development:
Lot 12 on N10576, 25 Wyuna Drive, Noosaville, Queensland
July 2024
Prepared for:
Sam Tatton
c/‐ SCG Consulting Engineers
Acid Sulfate Soil Assessment On‐site Wastewater Management Contaminated Land Assessment & Remediation
Dewatering Management Environmental Management Plans Surface & Groundwater Investigation & Monitoring
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ADG Consulting Pty Ltd
Report details
Project ref: ADG1673.24
ADG Project Contact: Michael Campbell
Report title: Dewatering Management Plan
Proposed Residential Development:
Lot 12 on N10576, 25 Wyuna Drive, Noosaville, Queensland
Version: Rev0
Author(s): Lilli O’Sullivan & Michael Campbell
Reviewer: Michael Campbell
Client: Sam Tatton
c/‐ SCG Consulting Engineers
Client contact: Tom Harrington – SCG Consulting Engineers
Distribution date: 12 July 2024
Distributed to: SCG Consulting Engineers
Copies: 1 PDF
ADG Consulting Pty Ltd
Lilli O’Sullivan BEnvSc Michael Campbell BEnvSc, BSc[Hons],
Environmental Scientist DipProjMgt, DipOHS, DipBusMgt, DipBus(Quality Auditing)
MEIANZ, MALGA, MASSI
Director & Principal Environmental Scientist
Date: 12 July 2024
This document and all its content is copyright. Apart from fair dealing for the purposes of study, research, criticism
and/or review as permitted under the Copyright Act 1968, no part of the content may be reproduced, reused or
redistributed without the prior written permission of ADG Consulting Pty Ltd.
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Table of Contents
1 INTRODUCTION 1
1.1 PROPOSED DEVELOPMENT 1
1.2 RELEVANT GUIDELINES 1
1.3 GENERAL ENVIRONMENTAL DUTY 1
1.4 DMP OBJECTIVES 2
1.5 SCOPE OF WORK 2
2 SITE CHARACTERISTICS 3
2.1 PROPERTY DESCRIPTION 3
2.2 SURROUNDING ENVIRONMENT 3
2.3 TOPOGRAPHY 3
2.4 GEOLOGY & SOILS 3
2.5 HYDROGEOLOGY 3
3 PREVIOUS INVESTIGATIONS 4
3.1 PTG CONSULTING 2024 4
3.1.1 SOILS 4
3.1.2 GROUNDWATER 4
3.2 GROUNDWATER QUALITY 4
4 WATER QUALITY OBJECTIVES 6
4.1 RECEIVING ENVIRONMENT 6
4.2 DEVELOPMENT OF WATER QUALITY OBJECTIVES 6
4.3 PROPOSED WATER QUALITY OBJECTIVES 7
5 DEWATERING METHODOLOGY 10
5.1 BASEMENT EXCAVATION AND SHORING 10
5.2 GROUNDWATER EXTRACTION 10
5.3 EXTRACTION/DISCHARGE RATES AND VOLUME 10
5.3.1 DEWATERING EXTRACTION CALCULATION BASED ON SUBSURFACE SOIL PROFILE 10
5.4 DEWATERING DURATION 11
5.5 GROUNDWATER DRAWDOWN 11
5.6 GROUNDWATER TREATMENT 12
5.7 NOMINATED HOLD POINTS 12
6 WATER QUALITY MANAGEMENT 13
6.1 RESPONSIBILITY 13
6.2 OPERATIONAL POLICY 13
6.3 PERFORMANCE CRITERIA 13
6.4 IMPLEMENTATION STRATEGY 13
6.4.1 GROUNDWATER TREATMENT SYSTEMS 13
6.4.2 DEWATERING STRATEGY 14
6.4.3 INITIAL PUMP‐OUT 14
6.5 MONITORING 14
6.5.1 VISUAL MONITORING 14
6.5.2 WATER QUALITY MONITORING 14
6.5.3 MONITORING RESPONSIBILITIES 15
6.6 MAINTENANCE 16
6.7 REPORTING 16
6.8 CONTINGENCIES 17
7 NOISE & ODOUR MANAGEMENT 18
7.1 RESPONSIBILITY 18
7.2 OPERATIONAL POLICY 18
7.3 PERFORMANCE CRITERIA 18
7.4 IMPLEMENTATION STRATEGY 18
7.4.1 NOISE 18
7.4.2 ODOUR 18
7.5 MONITORING 18
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7.6 REPORTING 19
7.7 CONTINGENCIES 19
8 LIMITATIONS 20
9 REFERENCES 21
APPENDIX A: FIGURES
APPENDIX B: DRDMW LICENCED BORE SEARCH
APPENDIX C: OPERATIONAL WORKS ‐ DRAWING 0282 ‐OW3.1
APPENDIX D: DEWATERING CALCULATION OUTPUT
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1 Introduction
ADG Consulting Pty Ltd (ADG) was engaged by Sam Tatton care of SCG Consulting Engineers (SCG) to
prepare a Dewatering Management Plan (DMP) for the proposed residential development within
property described as Lot 12 on N10576, situated at 25 Wyuna Drive, Noosaville, Queensland.
1.1 Proposed development
The proposed development comprises the construction of a two‐storey residential dwelling over a single‐
level in‐ground basement on the 641 m2 site. Supplied information indicates that excavations to facilitate
the basement construction will extend to a maximum of approximately 3.0 m below ground level (bgl) to
approximately ‐0.5 m Australian Height Datum (AHD; assuming local existing surface levels of around 2.5
to 2.7 m AHD). Localised deeper excavations may be required for the construction of other structural
elements (i.e. footings and pile caps), where required.
Groundwater seepage was recorded at a depth of approximately 2.4 mbgl (equating to an approximate
elevation of approximately 0.3 m AHD), during preliminary geotechnical investigations on the site by
PTG Consulting in June 2024. Given the sites proximity to the Noosa Inlet/Noosa River and the presence
of groundwater within the excavation extent, dewatering will be necessary to allow the basement to be
constructed in dry conditions.
1.2 Relevant guidelines
The DMP was prepared with reference to the following documents:
Australian and New Zealand Guidelines for Fresh and Marine Water Quality. 2018. Australian and
New Zealand Governments and Australian state and territory governments (ANZG), Canberra ACT,
Australia.
Australian and New Zealand Guidelines for Fresh and Marine Water Quality. 2000. Australian and
New Zealand Environment and Conservation Council and Agriculture and Resource Management
Council of Australia and New Zealand (ANZECC/ARMCANZ).
Environmental Protection (Water & Wetland Biodiversity) Policy 2019. Department of Environment
and Science (DES), Queensland Government.
Noosa River environmental values and water quality objectives. 2022. Department of Environment
and Science (DES), Queensland Government.
Guidelines for Managing Risks in Recreational Water. 2018. Australian Government, National Health
and Medical Research Council (NHMRC).
Monitoring and Sampling Manual 2018, Version 2 June 2018. 2018. Department of Environment and
Science (DES).
Queensland Water Quality Guidelines 2009, Version 3. 2013. The Department of Environment and
Heritage Protection (DEHP).
1.3 General environmental duty
The Environmental Protection Act 1994 describes that all persons in Queensland have a “General
Environmental Duty” and that “a person must not carry out an activity that causes, or is likely to cause
environmental harm unless the person takes all reasonable and practicable measures to prevent or
minimise the harm”.
The Act requires that appropriate action be taken to report that environmental harm is occurring or has
the potential to occur, unless the harm is authorised under an environmental protection policy, an
environmental management program, a development approval, or an environmental protection order.
This is known as the “Duty to Notify”. Failure to fulfil this duty is an offence and may result in prosecution.
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1.4 DMP objectives
The objectives of the DMP are to:
Describe the dewatering methodology, groundwater treatment, monitoring and reporting
procedures to be employed at the site during dewatering activities.
Provide effective management procedures to prevent environmental harm resulting from the
discharge of extracted groundwater from the site.
1.5 Scope of work
To achieve the investigation objectives, the following scope of work was undertaken:
A desktop study including:
1. Review of the development proposal and proposed shoring/dewatering designs.
2. Review of geology and soil maps for the area.
3. Search of groundwater bores licensed by the Department of Regional Development,
Manufacturing and Water (DRDMW) within a 200 m radius of the site.
4. Review of relevant existing reports and groundwater data from the local area.
5. Review of current aerial photographs of the site and surrounds.
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2 Site characteristics
2.1 Property description
The site is described as Lot 12 on N10576, and is situated at 25 Wyuna Drive, Noosaville, Queensland.
From recent available aerial mapping (Nearmap), the site contains a multi storey residential dwelling
planned for demolition and is generally rectangular in shape. The site has a total area of 641 m2. The site
locality is shown in Figure 1, Appendix A.
2.2 Surrounding environment
The surrounding environment and land use is described briefly in Table 1.
Table 1 Surrounding land use and environment
Direction Environment
North Noosa Inlet/Noosa River.
East Residential lots, then Noosa Inlet/Noosa River.
South Wyuna Drive, then multiple residential lots.
West Residential lots, then Noosa Inlet/Noosa River.
2.3 Topography
The site and surrounding land is considered to be generally level, with the site gently sloping towards the
Noosa River to the north with surface elevations ranging between approximately 2.7 m to 2.1 m AHD
from the southern boundary toward the north of the site.
2.4 Geology & soils
The surface geology at the site is mapped as being Pleistocene aged sandy mud, muddy sand and minor
gravel: estuarine channels and banks. The dominant rock type is identified as miscellaneous
unconsolidated sediments as referenced through detailed surface geology (accessed via Queensland
Globe online, 10 July 2024).
The Acid Sulfate Soils (ASS) map 1:100,000 scale categorises the site as ‘SEA’ or ‘Disturbed Land with
probability of ASS’, indicating that the site is likely to contain acid sulfate soils but the type and depth to
ASS has not been defined (accessed via Queensland Globe online, 10 July 2024).
2.5 Hydrogeology
A search of groundwater bores licensed by DRDMW was conducted by ADG on 10 July 2024. The search
identified no licensed bores within a 200 m radius of the site. A map showing the bore search area is
provided in Appendix B.
Based on the local geology and topography, and the site’s proximity to the Noosa River, the inferred
groundwater flow is to the north. Groundwater beneath the site is likely to be hydraulically connected to
the river, therefore saline groundwater conditions are anticipated, and additional saltwater intrusion is
likely to occur during dewatering.
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3 Previous investigations
This DMP is based on site specific information sourced from the following, provided to ADG by
SCG Consulting Engineers:
(Preliminary) Geotechnical Investigation, Proposed Residential Development, 25 Wyuna Drive,
Noosaville. June 2024. PTG Consulting. Ref: PTG/00259 – 0001 – Rev0.
Operational Works for Residential Development: Earthworks Plan – 25 Wyuna Dr, Noosaville, QLD.
Drawing set May 2024, SCG 0282‐CD Issue 1, (particularly Drawing 0282 ‐OW3.1). SCG Consulting
Engineers Pty Ltd (Refer Appendix C).
It is noted that dilapidation reports for surrounding structures and services are proposed to be
undertaken prior to commencement of construction and dewatering, however are to be provided to
Council separately from this DMP.
A brief discussion of relevant soil and groundwater conditions is provided below.
3.1 PTG Consulting 2024
A preliminary Geotechnical Investigation and concurrent Acid Sulfate Soils Investigation was undertaken
at the site in May 2024 (reported June 2024) by PTG Consulting.
3.1.1 Soils
A total of one (1) borehole (BH1) was drilled on the proposed development footprint to 6.0 mbgl.
The subsurface profile encountered is generally described as silty sand fill material at the ground surface,
extending to the depth of 2.6 m. Fill material is underlain by natural sand and silty sand which is initially
loose, becoming denser with depth, extending to depths ranging between 2.6 m to the 6.0 m termination
depth.
Alongside the Geotechnical Investigation (2024), Acid Sulfate Soil (ASS) samples were collected at 0.5 m
intervals in BH1 to 6.0 m depth. A total of twenty‐four (24) samples were collected for ASS screening and
four (4) samples were selected for further analysis by the Chromium Reducible Sulfur suite (CRS).
ADG notes that the testing was limited to one borehole with ASS testing to 6.0 m depth, and PTG reports
that within part of this depth profile the natural sands are considered to contain potential ASS requiring
liming at rates of up to 12 kg/tonne. Additionally, on‐site fill material is considered to contain potential
ASS requiring limiting rates of to 3.6 kg/tonne. All excavated spoil from depths below RL 5 m AHD within
the excavation footprint will be appropriately neutralised with lime and validated in accordance with
recommendations by PG in the ASS Investigation Report (PTG, 2024).
3.1.2 Groundwater
During drilling activities for the Preliminary Geotechnical Investigation, groundwater seepage/inflow was
encountered at 2.4 m depth below the ground surface (PTG, 2024) (inferred approx. 0.3 m AHD from SCG
OPW civil drawings).
It should be noted however, that groundwater depths and ground moisture conditions are affected by
weather and climatic conditions, tidal variations, surface and subsurface drainage/permeability
conditions, and human influence and will therefore vary with time. Groundwater levels are expected to
be similar to the water level in the river to the north, albeit somewhat a dampened response to tidal
variations.
3.2 Groundwater quality
No groundwater quality data was obtained by PTG as part of the preliminary geotechnical investigation.
However, based on numerous groundwater investigations and dewatering monitoring projects that have
been undertaken by ADG throughout the Noosa Coast Region in recent years, our understanding of the
groundwater quality in the region is provided below:
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Groundwater is generally mildly acidic to neutral, with pH levels ranging from approximately 5.5 to
6.5 and electrical conductivity ranging from brackish to saline between 2,000 µS/cm to
48,000 µS/cm. Groundwater pH has the potential to reduce (become more acidic) following
oxidisation of PASS as dewatering progresses, particularly if re‐wetting of the soils occurs.
Dissolved oxygen levels in static groundwater typically range from approximately 35 – 40 %
saturation.
The groundwater associated with indurated sand strata is moderately to highly turbid as a result of
staining and organic content.
Concentrations of dissolved metals are typically below the available marine water trigger values
(MWTV’s) provided in ANZECC/ARMCANZ (2000) for the receiving waters, however elevated levels
of aluminium and particularly iron are expected in the untreated groundwater and have the
potential to increase following oxidisation of PASS as dewatering progresses or as a result of existing
acidic groundwater conditions.
Given the location and previous use of the site, groundwater impacts resulting from site
contamination are not anticipated.
A groundwater investigation will be undertaken at the commencement of dewatering as described in
Section 6.5.2 of this report. This assessment will be representative of the groundwater being extracted
and treated from the entire site, as opposed to localised monitoring well data which is often misleading.
Based on previous experience with dewatering in the area, ADG expects the groundwater to require
treatment to increase pH and dissolved oxygen levels, as well as reduce turbidity, suspended sediments
and dissolved metal concentrations prior to being discharged to the Noosa River.
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4 Water quality objectives
4.1 Receiving environment
It is proposed to discharge extracted groundwater directly over the revetment wall into the Noosa River
adjacent to site. The exact location of the receiving waters/environment will be confirmed on
commencement of dewatering.
The receiving environment in this location identifies as a moderately disturbed, middle estuary
environment. The following section establishes water quality objectives (WQOs) to ensure that the
environmental values of the receiving waters are protected and maintained.
4.2 Development of water quality objectives
WQOs have been developed to support and protect the designated environmental values (EVs) for the
receiving environment. The WQOs are based on a moderately disturbed level of protection for enclosed
coastal/lower estuaries. The WQOs have been developed with reference to the following guideline
documents:
Australian and New Zealand Guidelines for Fresh and Marine Water Quality 2018. (ANZG 2018) The
selected trigger values apply to moderately disturbed systems to provide a 95% level of species
protection for marine waters.
Environmental Protection (Water & Wetland Biodiversity) Policy 2019. 2019. Queensland
Government.
Noosa River environmental values and water quality objectives. 2022. DES.
Queensland Water Quality Guidelines, Version 3, September 2009. 2013. DEHP.
The Australian and New Zealand Guidelines for Fresh and Marine Water Quality by the Australian and
New Zealand Environment and Conservation Council and Agriculture and Resource Management Council
of Australia and New Zealand (ANZECC/ARMCANZ, 2000), has undergone review, with the publication of
the 2018 version. The revised Australian and New Zealand Guidelines for Fresh and Marine Water Quality
2018 is a joint initiative between the Australian and New Zealand Governments and Australian state and
territory governments (ANZG, 2018) and supersedes the ANZECC/ARMCANZ 2000 publication. Where
ANZECC/ARMCANZ (2000) is referenced, the relevant sections are still relevant and consistent with the
updated ANZG 2018 publication, as referenced in the ANZG 2018 publication.
The Queensland Water Quality Guidelines 2009 (DEHP, 2013) was made pursuant to the provisions of the
Environmental Protection (Water) Policy 1999, now the Environmental Protection (Water & Wetland
Biodiversity) Policy 2019 (the EPP(Water)), which is a subordinate legislation under the Environmental
Protection Act 1994 and was developed as the State response to the ANZECC/ARMCANZ (2000)
Guidelines. The EPP(Water) provides a framework for:
Identifying environmental values for Queensland waters, and deciding the water quality objectives
to protect or enhance those environmental values.
Including the identified environmental values and water quality objectives under Schedule 1 of the
EPP (Water).
WQOs are long term goals for surface water quality management. They are indicators established for
receiving waters to support and protect the designated Environmental Values (EVs) for those waters. DES
(2022) describes that for slightly to moderately disturbed waters, the guideline values should be
compared with the median of values at a test site, whilst ANZG (2018) stresses that the aquatic ecosystem
guideline values are triggers to further action, are inherently conservative, and that the response to non‐
compliance should match the magnitude and impacts (if any) of the exceedance.
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Regardless of the WQOs adopted in this DMP, the General Environmental Duty set out in the EP Act is
paramount, which requires that “a person must not carry out an activity that causes or is likely to cause
environmental harm unless the person takes all reasonable and practicable measures to prevent or
minimise the harm”.
4.3 Proposed water quality objectives
The proposed water quality objectives that have been developed for the discharge of extracted
groundwater from the site are provided in the Tables below. All water discharged from the site must
comply with the discharge criteria provided in Table 2. In addition, the receiving water quality within a
20 m radius of the discharge point entry to the receiving water shall comply with the receiving water
criteria provided in Table 3. Receiving waters data will be assessed against background monitoring data
if non‐compliant results are obtained at the receiving waters monitoring location.
Table 2 Discharge criteria
Parameter Criteria
Physico‐chemical
pH (pH units) 6.5 – 8.51
Dissolved oxygen (% saturation) ≥802
Suspended solids (mg/L) ≤501,2
Turbidity (NTU) ≤502
Litter None visible
Totals metals (µg/L)
Aluminium No ANZG criteria / 2003
Iron No ANZG criteria / 3003
Table notes:
1. QWQG 2009 (2013) Refer to Table 8.2.1. Summary of design objectives for management of stormwater quality and flow –
construction phase of development in Queensland.
2. Typical discharge criteria recognised throughout Queensland & NSW.
3. Criteria subject to anticipated Development Application (DA) notice and conditions by Noosa Shire Council.
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Table 3 Receiving waters criteria
Parameter Criteria
Physico‐chemical
pH (pH units) 7.5 – 8.11
Dissolved oxygen (% saturation) 85 – 1051
Suspended solids (mg/L) ≤161
Turbidity (NTU) ≤131
Dissolved metals (µg/L)
Aluminium No relevant ANZG criteria available
Arsenic 2.32*
Cadmium 5.52
Chromium 4.42
Copper 1.32
Iron No relevant ANZG criteria available
Lead 4.42
Nickel 702
Zinc 82
Mercury 0.42
Totals metals (µg/L)
Aluminium No ANZG criteria / 2003
Iron No ANZG criteria / 3003
Table notes:
1. DES (2022). Noosa River environmental values and water quality objectives (middle estuary waters) – Weyba Creek.
2. ANZG (2018). Supersedes ANZECC/ARMCANZ (2000) ‐ Marine water trigger values for 95% species protection.
3. Criteria subject to expected condition in Development Application (DA) notice by Noosa Shire Council.
* = Insufficient data to derive a reliable trigger value. Low reliability value adopted (refer ANZECC/ARMCANZ (2000) Section
8.3.7.
Although ADG has not been provided a copy of the DA notice and conditions for the proposed
development, based on previous dewatering projects in the Sunshine/Noosa Coast Region it is expected
that total iron and aluminium concentrations as listed in Table 3 (above) are likely to be conditioned by
Noosa Shire Council for compliance. It should be noted that these concentrations are considered to be
onerous with respect to the risk‐based (worst‐case) bioavailable trigger value criteria contained in ANZG
2018 & ANZECC/ARMCANZ (2000) for marine water (moderately disturbed) 95% species protection, and
are likely to be difficult to achieve given the groundwater conditions encountered in the locality on
previous dewatering projects on the Sunshine/Noosa Coast.
Prior to discharge to the stormwater system or any waterway, discharges are to be tested to meet the
requirements of the ANZG 2018 & ANZECC/ARMCANZ (2000) Guidelines for Fresh and Marine Water
Quality. There is currently no chemical toxicant trigger value criteria available for total or dissolved (i.e.
bioavailable) concentrations of aluminium or iron for marine or estuarine waters under the Australian
and New Zealand Guidelines for Fresh and Marine Water Quality Guidelines (ANZG 2018 &
ANZECC/ARMCANZ 2000 – i.e. ANZECC Guidelines) or the Guidelines for Managing Risks in Recreational
Waters (NHMRC 2008), with regards to managing environmental impacts to the waterway.
In addition, Section 5 (Guidelines for recreational water quality and aesthetics) of the ANZECC/ARMCANZ
(2000) Guidelines (per section 5.2 thereof) was superseded by the Guidelines for Managing Risks in
Recreational Water in 2008 (NHMRC, 2008). Therefore, a reference to the ANZECC/ARMCANZ (2000)
Guidelines is by association and extension a reference to the current 2008 NHMRC Guidelines. The 2008
NHMRC Guidelines contain no criteria for aluminium, and only includes an aesthetic criterion for iron –
noting this is an aesthetic criterion derived from the Australian Drinking Water Guidelines on the basis of
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ingesting 2L of the recreational water solution per day. ANZECC/ARMCANZ (2000) Section 5.2.3.3, notes
that as a general guideline, under Toxic Chemicals, ‘Higher concentrations of toxicants may be tolerated
occasionally if it assumed that no person will ingest more than a maximum of 100 mL water during a
normal swimming session (NHMRC 1990) compared with 2L/d for potable water’, and Section 3.1.1.3,
under Risk based approach of the guidelines, ‘The guideline trigger values are based on bioavailable
concentrations, and hence are relatively conservative when compared with total concentrations in the
field, so the use of the decision frameworks will increase guideline concentrations in most cases’.
Therefore, any chemical toxicant trigger values would require reassessment and likely increase upwards
of any ANZG 2018 &/or ANZECC/ARMCANZ (2000) Guideline trigger values due to the slightly to
moderately disturbed nature (and thereby reduced sensitivity) of the receiving waters.
In conditioning more onerous criteria, rather than the available marine chemical toxicant trigger value
criteria contained within the ANZG/ANZECC Guidelines, an unachievable constraint may be placed on the
development. This DMP has allowed for contingency measures to be incorporated into the treatment
and discharge system if required, including silt curtains to be installed within the receiving waterway
surrounding the discharge location, or further onsite treatment measures such as filtration, to prevent
and/or minimise as far as reasonably practicable the potential for release of suspended solid loads into
the broader receiving waterway.
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5 Dewatering methodology
5.1 Basement excavation and shoring
It is understood that the excavation/basement perimeter will be stabilised along the perimeter of the
basement excavations using a contiguous secant pile wall (refer to supplied indicative basement shoring
design at Appendix C). Excavations to facilitate the construction of the basement will extend to
approximately 3.0 m below ground level (bgl) to approximately ‐0.5 m Australian Height Datum (AHD;
assuming local existing surface levels of around 2.5 to 2.7 m AHD). Localised deeper excavations may be
required for construction of other structural elements (i.e. footings & pile caps).
Groundwater seepage was recorded at a depth of approximately 2.4 mbgl (equating to an approximate
elevation of approximately 0.3 m AHD), during preliminary geotechnical investigations on the site by
PTG Consulting in June 2024. All excavated spoil from within the excavation footprint will be
appropriately neutralised with lime and validated in accordance with recommendations by PTG
Consulting in the Preliminary Geotechnical Investigation Report (PTG, 2024).
It is expected that the development will include a ‘tanked’ basement to prevent the requirement for a
permanent dewatering facility at the site.
5.2 Groundwater extraction
Dewatering is anticipated to be undertaken using a series of 6.0 m length, 40 mm diameter PVC spears
installed to below maximum excavation depth at 1.5 m intervals around the internal and external
perimeter of the basement excavation (refer to supplied indicative shoring design at Appendix C).
The basement excavation must be dewatered to a minimum of approximately 1.0 m below the deepest
point of excavation to allow construction to be undertaken in dry conditions. The water table is therefore
expected to be lowered by a minimum of approximately 1.8 m to around ‐1.9 m AHD. It is expected that
the cone of depression in the standing groundwater table will be predominantly limited to within the site
boundaries.
It is proposed that the development will include a ‘tanked’ basement to prevent the requirement for a
permanent dewatering facility at the site. Similarly, no permanent groundwater dewatering is proposed
or likely to occur as a result of the development, with all services and pipework proposed to be situated
above standing groundwater elevations (that is, at elevations above 0.6 mAHD) and subject to the
nominated hold points at Section 5.7. Where any deviation is proposed from this arrangement, all
pipework within the saturated zone, that outlets direct to waterways must be fitted with buried
headstocks at suitable intervals to prevent ongoing dewatering of groundwater along pipework bedding.
5.3 Extraction/discharge rates and volume
5.3.1 Dewatering extraction calculation based on subsurface soil profile
The dewatering extraction rate, area of influence and cone of depression has been estimated using the
Western Australian Department of Water and Environmental Regulation Cone of Depression Calculator.
The calculation results are based on the following parameters (as provided by SCG) and known site‐
specific conditions. The following is applicable to the basement excavations spanning across the lot:
Approximate length of excavation = 20 m
Approximate width of excavation = 18 m
Reduction in depth of groundwater across the basement footprint/excavation = 1.8 m
Approximate depth of saturated aquifer = 10 m (standardised conservative value applied)
The soil profile of comprised predominantly of fine to medium grained silty sands, which has a hydraulic
conductivity of 8.2 m/day, or equivalent 0.0000949 L/sec (WA Calculator). The results of the calculation
are shown in Table 4 below, and a copy of the output is provided in Appendix D.
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Table 4 Dewatering extraction rate results
Output Result
Effective radius of dewatering spears (m) 11
Dewatering radius of influence (m) 53
Discharge rate (L/sec) 6
Discharge rate (L/hr) 21,600
Establishment of cone of depression (hours) 44
Based on the above inputs, a groundwater flow rate of approximately 6 L/sec or 360 L/min or 21,600 L/hr
has been predicted for the development, with the estimated cone of depression radius to be
predominantly limited to within 3 m of the secant pile shoring wall. Flow rates are predicted to be highest
during initial drawdown of the groundwater table within the basement excavation footprint, and
reducing to approximately 5 L/sec following establishment of the cone of depression within the
excavation. Flow rates may fluctuate due to tidal variations, generally approximately ± 0.5 m, and will
also be influenced by rainfall and surface water collection within the basement excavation footprint
noting the underlying predominantly sand profile encountered during geotechnical investigations.
Regardless of the contractor employed, groundwater treatment systems should be installed with
capability for treating flow rates of up to 8 to 10 L/sec, as a contingency against higher than anticipated
flow rates exceeding the estimated 6 L/sec as a result of varying ground conditions across the extent of
excavation.
However, it should be noted that the WA Calculator provides a conservative assessment of inflows to an
excavation footprint based on area and depth but does not take account of the method of perimeter
piling i.e. steel sheet pile, which will inhibit lateral inflows. Also note that the cone of depression radius
measure includes water table depressions of 1 mm depth or more, so any significant depression of the
water table is limited to much closer to the spear point dewatering spears (generally within 3 to 10 m
from the shoring wall in fine‐medium grained sands, depending on density of the strata).
5.4 Dewatering duration
Dewatering will be necessary throughout the basement construction phase, which is expected to require
dewatering for approximately 8 to 12 weeks. To minimise the potential impacts during construction of
short‐term dewatering, periods of active dewatering will be minimised as much as possible. However,
ADG notes that once active dewatering has commenced, dewatering will not be able to be ceased until
both: a) the basement hydrostatic uplift forces have been compensated to the satisfaction of the
consulting RPEQ engineer; and b) potential hydraulic loading on the external face of the sheet pile shoring
system has been compensated to the satisfaction of the consulting RPEQ engineer and shoring
contractor.
5.5 Groundwater drawdown
Groundwater drawdown caused by dewatering has the potential to create settlement in unconsolidated
sediments and loose sands. It is noted that dilapidation reports for surrounding structures and services
have been undertaken which were not supplied to ADG for the purposes of preparing this DMP, and are
to be provided to Council separately from this DMP.
Groundwater drawdown may also oxidise potential acid sulfate soils within the cone of depression,
subsequently producing acidic groundwater conditions and mobilising heavy metals. Monitoring of the
extracted untreated groundwater will be undertaken to detect potential in‐situ oxidation, as required
and at the frequencies stated in Section 6.5.2. Groundwater monitoring bores for groundwater level
gauging external to the excavation footprint are unable to be established and monitored prior to and
during construction on the site, due to limited space (SCG Consulting Engineers).
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A plan showing the proposed shoring and dewatering system is provided at Appendix C.
5.6 Groundwater treatment
All extracted groundwater will be treated on‐site using available technologies prior to discharge to the
stormwater network. The following treatment measures (or similar depending on final dewatering
contractor selection) will be adopted, and will be installed and operational prior to the commencement
of dewatering:
1. A groundwater pH buffering treatment system (primary treatment)
2. A sedimentation tank to provide additional residence time and sedimentation (secondary
treatment).
3. Installation of fine media filtration to retain suspended sediments and/or heavy metals (tertiary
treatment), if required.
Details of the treatment systems and methodologies are provided in Section 6 of this report.
Note: Consideration should be taken, regarding placement of treatment gear on site to enable easy
cleaning and maintenance throughout the dewatering phase for the project. Consider the potential
requirement for regular de‐sludging of sedimentation tank/s to suitable area onsite, if available (cost
minimisation).
5.7 Nominated Hold Points
In accordance with anticipated DA Conditions, nominated hold points to be enacted during construction
have been proposed to facilitate for certification by the suitably qualified person experienced with Acid
Sulfate Soils, as well as Council Development Engineer to ensure all possible avenues for continual
dewatering below permanent groundwater level, including around pipework bedding that outlet to
waterways, are appropriately sealed. The nominated hold points regarding dewatering for this project
are:
1. Prior to commencement of dewatering/initial pump out
2. At finished excavation level, prior to blinding layer application
3. External to basement service installation trench opening/s prior to backfilling.
The above nominated hold points are subject to confirmation by the consulting engineer, and liaison with
council representatives and the Site Manager.
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6 Water quality management
6.1 Responsibility
The Site Manager is ultimately responsible for implementing the water quality management procedures
described in this DMP.
6.2 Operational policy
To prevent impacts on the receiving waters by effectively treating all extracted groundwater prior to
discharge from the site.
6.3 Performance criteria
The performance criteria for the discharge of extracted groundwater are the water quality objectives
provided in Table 2 and Table 3 in Section 4 of this report. Both the discharge and receiving waters (within
a 20 m radius of the stormwater discharge point) will be assessed against the WQOs to ensure that the
environmental values of the waterway are maintained. Receiving waters data will also be assessed
against background monitoring data if non‐compliant results are obtained at the receiving waters
monitoring location.
6.4 Implementation strategy
All extracted groundwater will be treated on‐site using available technologies prior to discharge to the
stormwater network. The treatment system described in Section 6.4.1 will be adopted, installed and
operational prior to the commencement of dewatering.
6.4.1 Groundwater treatment systems
Subject to final appointment of shoring and dewatering contractors (who all generally have different
treatment systems), the following treatment systems are generally proposed for dewatered groundwater
treatment prior to discharge. Regardless of the contractor employed, groundwater treatment systems
should be installed with capability for treating flow rates of up to 8 to 10 L/sec, as a contingency against
higher than anticipated flow rates exceeding the estimated 6 L/sec as a result of varying ground conditions
across the extent of excavation.
Primary treatment
A groundwater treatment system will be installed to provide primary treatment of the extracted
groundwater. The system will provide the following capabilities:
1. A baffled treatment tank with 5 kL minimum capacity
2. Automated in‐line chemical dosing systems for the addition of buffering solutions and coagulants
3. A filtration system to reduce fine particulates (if required)
4. Emergency response alarms for non‐routine situations.
Based on the estimated extraction rate, this system will provide approximately thirteen minutes contact
time during the initial chemical dosing, prior to secondary treatment using a sedimentation tank. Primary
treatment tank will be vertically stacked on the secondary treatment tank wherever practicable to
minimise site area required for groundwater treatment equipment.
Secondary treatment
A 23 kL sedimentation tank will be utilised to provide the necessary residence time for secondary
treatment of the groundwater prior to discharge to the stormwater system. Based on the estimated
groundwater extraction rate of approximately 21,600 L/hr (equivalent 360 L/min) from Section 5.3.1 of
this Report, one sedimentation tank will provide approximately sixty‐three minutes retention time
following primary treatment of the extracted groundwater. This is considered to be sufficient secondary
settling / retention time based on extensive prior experience on other sites in similar ground conditions.
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Tertiary treatment – may be required following initial testing of extracted groundwater.
A filtration treatment system with specialised fine filtration media and chlorine dosing will be utilised to
provide the required heavy metal removal (specifically for total and dissolved iron) where not
precipitated and retained within the sedimentation tank/s (secondary treatment). This treatment system
will provide tertiary treatment of the groundwater prior to offsite discharge. This type of fine media
filtration treatment system is a forced‐flow system under pressure, and generally capable of treating flow
rates of up to 20 L/sec per filtration unit (therefore residence time is inconsequential to treatment quality
achieved).
Tertiary treatment will only be required if the required water quality is unable to be achieved following
primary and secondary stages of treatment. Subject to the results of field and laboratory testing during
the pre‐discharge monitoring event.
6.4.2 Dewatering strategy
The Site Manager, Dewatering Contractor and ADG Consulting must formulate a dewatering strategy to
ensure that the dewatering treatment system is sufficient to meet the requirements of the project and
that the necessary equipment can be accommodated within the site prior to the commencement of
dewatering.
Where the construction of the proposed development requires occupation of the road reserve (verge
area and/or road formation) for either short term or long term, a road reserve permit must be obtained
from Council prior to any occupation of the road reserve.
6.4.3 Initial pump‐out
Prior to discharge of any extracted groundwater to the canal system, the following pre‐dewatering
procedure will be undertaken:
1. The basement area will be excavated down to the standing groundwater level.
2. The initial dewatering discharge will be directed (via the treatment systems) into the excavation and
allowed to infiltrate/recharge the aquifer. This process will provide initial clarification of the extracted
groundwater as disturbed sediment loads are typically reduced following the initial pump‐out.
3. Samples of the treated groundwater will be recovered and analysed for the parameters detailed in
Table 2 and Table 3.
4. The extracted groundwater will be directed into the canal system following confirmation that the
water quality complies with the discharge criteria.
6.5 Monitoring
6.5.1 Visual monitoring
Visual inspections of the site and dewatering equipment shall be undertaken daily by the Site Manager
to identify the following:
Quantity of chemical product within the dosing system
Effective operation of all dewatering treatment equipment
Short circuiting of water around baffles and filter media in sediment tanks, where required to be
installed.
Visible hydrocarbon sheens and odours
Green blue or extremely clear water indicating high levels of dissolved aluminium.
6.5.2 Water quality monitoring
Water quality monitoring will be undertaken for the duration of dewatering activities at the site by a
suitably qualified and independent person. The monitoring will include analysis of the extracted
groundwater, treated discharge water and off‐site monitoring in the receiving waters (in the mixing zone
within a 20 m radius of the discharge point). The exact location within the receiving waterway (Noosa
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River) is to be confirmed, however it is anticipated to be directly north of the site. Background water
quality monitoring of field parameters will also be conducted during each sampling event, if applicable.
Background samples will be recovered from the river, either upstream or downstream from the receiving
water location (tide dependant).
The proposed monitoring locations are shown in Figure 1, Appendix A are a subject to confirmation
following mobilisation of dewatering gear to site.
Monitoring will be undertaken at the following frequencies:
Daily monitoring of field parameters (pH, electrical conductivity, dissolved oxygen, temperature and
turbidity) in the treated discharge water and pH of the untreated extracted groundwater (to
determine potential acidification). Daily monitoring will be undertaken by a suitably trained site
employee under the supervision of the Site Manager.
Weekly monitoring of field parameters (pH, electrical conductivity, dissolved oxygen, temperature
and turbidity) in the untreated extracted groundwater, treated discharge water, receiving waters
and background waters by ADG Consulting.
Weekly laboratory analysis of treated discharge water and receiving waters for suspended solids
and dissolved 0.45µm filterable metals (aluminium, arsenic, cadmium, chromium, copper, iron, lead,
nickel, zinc and mercury). Total aluminium and iron will also be analysed for, if required.
Pre‐discharge/initial monitoring of field parameters (pH, electrical conductivity, dissolved oxygen
and oxidation‐reduction potential) in the extracted groundwater (prior to treatment) to assess
changes in groundwater chemistry associated with PASS oxidation.
Pre‐discharge/initial laboratory analysis of extracted groundwater (prior to treatment) for
suspended solids, dissolved 0.45µm filterable metals (aluminium, arsenic, cadmium, chromium,
copper, iron, lead, nickel, zinc and mercury) and for soluble sulfate and chloride to assess changes
in groundwater chemistry associated with PASS oxidation. Total aluminium and iron will also be
analysed, if required.
Laboratory analysis of untreated groundwater would also be performed periodically (monthly) if
changes in untreated groundwater pH levels are detected that may indicate local acidification, and
to determine any changes in local groundwaters that may require further investigation of potential
environmental impacts.
All samples will be recovered by a suitably qualified Environmental Scientist and submitted to a National
Association of Testing Authorities (NATA) accredited laboratory for analysis.
6.5.3 Monitoring responsibilities
The persons responsible for undertaking the compliance monitoring described in Section 6.5.2 above are
shown in Table 5.
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Table 5 Monitoring responsibilities
Activity Frequency Responsibility Person
Monitoring of field parameters in discharge water
Daily Site Manager Site Manager
and untreated extracted groundwater
Monitoring of field parameters in untreated
Environmental
extracted groundwater, discharge water, Weekly ADG Consulting
Consultant
receiving waters and background waters
Laboratory analysis of samples recovered from Environmental
Weekly ADG Consulting
discharge water and receiving waters Consultant
Monitoring of field parameters in extracted Environmental
Weekly ADG Consulting
groundwater (pre‐treated) Consultant
Laboratory analysis of samples recovered from Initially, then as Environmental
ADG Consulting
extracted groundwater (pre‐treated) required Consultant
6.6 Maintenance
The groundwater treatment systems must be regularly maintained. Maintenance must include:
Regular cleaning and or replacement of the filters within the filtration unit, where required to be
installed.
Regular removal of sediment from the sedimentation tank. The sediment must be either returned
to the excavation pit for dewatering and bulking out with excavated material, or removed from the
site by a licensed liquid waste contractor.
Regular check of the dosing system and top‐up of buffering solutions and flocculants.
6.7 Reporting
Dewatering management procedures and monitoring results will be reviewed by ADG Consulting weekly
to ensure that the treatment procedures are effective, and that the receiving waters are not being
impacted by the extracted groundwater being discharged.
The following reporting procedures will be adopted:
A summary report will be prepared upon completion of the initial pre‐discharge monitoring. The
report will be submitted to the Site Manager, Dewatering Contractor, and NSC upon request.
Weekly interim reports will be prepared upon receipt of laboratory data for each round of ongoing
compliance monitoring. The interim reports will display all data obtained during the previous
monitoring event, and provide comments and recommendations based on the results.
A dewatering compliance report will be prepared on completion of the project (upon request).
The above reports will be prepared by ADG Consulting and provided to the Site Manager and Dewatering
Contractor as they become available. The reports will include all water quality results and comparison to
the WQOs, corrective actions and recommendations made to the Site Manager and Dewatering
Contractor during the monitoring period.
The Site Manager must keep records of complaints, volumes of chemicals used, and treatment methods
employed. These records must be available on‐site at all times and submitted to NSC by the Site Manager
upon request.
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6.8 Contingencies
If water quality monitoring indicates ongoing exceedances of the performance criteria, and the water
quality objectives for the receiving waters cannot be met, then corrective actions will be adopted as
necessary. Possible contingencies may include one or more of the following:
Installation of additional sedimentation tanks to provide increased residence time and assist with
the retention of precipitated iron hydroxides, other heavy metals and/or suspended sediments.
Installation of additional flocculant and/or coagulant dosing systems to assist in precipitation of
suspended sediments and/or heavy metals.
Installation of activated carbon filtration or other fine media filtration to retain suspended
sediments and/or heavy metals.
Install a floating sediment curtain/s around the stormwater termination point in the receiving
waterway to prevent unsightly plumes and contain sediment and/or heavy metals for periodic
removal (subject to approval by Noose Shire Council).
Preventive and corrective actions shall be taken in the event that groundwater monitoring
observations indicate that unexpected groundwater contamination has been encountered during
dewatering. The most appropriate action(s) shall be dependent on the stage of construction and
risk of adverse impacts to groundwater users and the receiving environment.
Any modification to the dewatering system and pumping rates shall be in consultation with a
suitably qualified scientist/geotechnical/engineer.
Following heavy rainfall all ponded surfaces waters are to meet discharge criteria (Table 3) prior to
offsite discharge. Where discharge criteria not met, Site Manager to obtain approval from
Dewatering Contractor regarding treating surface waters with treatment gear before offsite
discharge.
Pumping systems and shoring works to be maintained in fit for purpose state by Dewatering
Contractor and/or shoring contractor. In the event that dewatering equipment has failed and is
likely to cause a significant impact on the environment, or surrounding properties (i.e. flooding) the
Dewatering Contractor is to be contacted immediately. The Principal Contractor, in consultation
with the Dewatering Contractor shall be responsible in rectifying the failure in a practicable time
frame to minimise potential impacts. Equipment, spare parts, materials and tools necessary to
manage aspects of the system/s which present a high risk of significant impacts in the event of
failure (if any) shall be readily available.
Construction vibrations could potentially cause settlement in the loose upper level sands, thereby
damaging nearby structures founded in these strata. Prior to commencement of construction on
site (including staged works), it is recommended that a detailed dilapidation survey be undertaken
to establish the condition of all existing adjacent structures, roads and services.
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7 Noise & odour management
7.1 Responsibility
The Project Manager is responsible for ensuring the appropriate management of noise and odour during
dewatering operations.
7.2 Operational policy
To minimise noise and odour emissions generated from the site during dewatering.
7.3 Performance criteria
The appropriate criteria to measure the performance of dewatering management at the site are provided
below.
1. No noise or odour related complaints received from neighbouring residents or the community.
2. No degradation of air quality due to fumes or odours emanating from the dewatering process.
7.4 Implementation strategy
Noise and odour emissions will be managed as described in the following sections.
7.4.1 Noise
All dewatering equipment must be operated appropriately and maintained in good working order. All
dewatering systems and plant must be fitted with the appropriate noise reduction equipment to comply
with the performance criteria. Non‐complying dewatering plant will be replaced or repaired as necessary.
It is proposed to employ noise mitigation strategies including use of electric pumps and dewatering
systems rather than diesel powered equipment. Noise attenuation blankets and screens will be installed
around noise generating dewatering pumps and equipment where practicable. Noise monitoring
equipment (unattended) will be installed by the site manager prior to commencement and monitored for
the duration of dewatering.
7.4.2 Odour
All dewatering plant must be fitted with the appropriate emission reduction devices. Where practicable,
all dewatering plant will be sealed to prevent the release of odours to the atmosphere. Fine mist odour
control sprays will be applied to reduce offensive odours if complaints are received from neighbouring
residents.
7.5 Monitoring
An inspection of the site and dewatering equipment shall be undertaken daily by the Site Manager to
identify the following:
Excessive noise being generated by the dewatering systems and plant; and
Strong or offensive odours being generated by the dewatering equipment and/or extracted
groundwater.
If required by Council, noise monitoring equipment (unattended, continuous logging) is proposed to be
installed by the Site Manager prior to commencement and monitored for the duration of dewatering.
The Environmental Protection (Noise) Policy 2019 (EPP(Noise)) identifies specific acoustic quality
objectives (noise criteria) to assist in preventing significant impacts on noise sensitive receptors and as a
guide to long‐term acoustic quality for sensitive receptors. The primary EPP(Noise) criteria relevant to
this investigation is outside a dwelling (i.e. adjacent dwellings), which should not have noise at levels in
the daytime or evenings greater than 50dB(A) LAeq, adj,1hr. This means that noise levels in the receiving
environment outside of nearby dwellings (i.e. on balconies) should not exceed an equivalent sound
energy as would be received from a one hour continuous sound of 50 decibels on the A‐weighted scale
(adjusted for tonal character perceptible by the human ear).
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While this report has not been generated for the purpose of assessing compliance with the requirements
of workplace health and safety legislation, it is noted that a person conducting a business or undertaking
must ensure that workers are not exposed to noise that exceeds the exposure standard for noise. The
exposure standard for noise is defined in the Work Health & Safety Regulation 2011 (QLD) as LAeq,8h of
85 dB(A) or an LC,peak of 140 dB(C). As such, it is considered appropriate to adopt these exposure
standards to assess average and peak noise generated at the site with the potential to affect exposure
levels of nearby sensitive receptors (noting there will be some attenuation between source and receptors
and actual noise experienced by receptors would need to be measured at the receptor location).
7.6 Reporting
The Site Manager must keep records of complaints, monitoring records (including continuous noise
monitoring data), and corrective and preventive actions/methods employed for noise abatement. These
records must be available on‐site at all times and submitted to NSC by the Site Manager upon request.
7.7 Contingencies
If noise levels consistently exceed the performance criteria, temporary acoustic barriers will be
constructed around the offending dewatering systems and plant. Odour control sprays will be applied as
necessary to mask odour emissions if complaints are received from neighbouring residents. This may
include the direct injection of deodorisers to the groundwater treatment system.
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8 Limitations
ADG Consulting Pty Ltd has prepared this report for Sam Tatton and SCG Consulting Engineers in
accordance with the agreed scope of work. The services performed by ADG have been conducted in a
manner consistent with the normal level of care and expertise exercised by members of the
environmental consulting profession. No other warranty or guarantee, expressed or implied, is made as
to the professional advice included in this report.
This report is solely for the use of Sam Tatton and SCG Consulting Engineers and ADG accepts no
responsibility for the use of any part of this report for any other purpose or by third parties, as it may not
contain sufficient information for the purposes of other parties or users. This report must only be
presented in full, and may not be used for any other objective, except where prior written approval is
obtained from ADG. This report does not comment on legal obligations, as legal advice can only be given
by qualified legal practitioners.
The information contained in this report is provided to minimise potential impacts on the receiving
environment, however implementation of the described management procedures does not guarantee
that the objectives will be achieved.
The information contained in this report is considered to be accurate at the date of issue. Subsurface
conditions, including contaminant concentrations can change in space and time, either through natural
processes or by the accidental or intentional addition of contaminants to a site. Where conditions
encountered subsequently at the site are significantly different from those reported herein, ADG must
be notified and be provided the opportunity to review the conclusions and recommendations of this
report.
ADG1673.24 Dewatering Management Plan_Rev0_12.07.24 Page 20
Page 46
ADG Consulting Pty Ltd
9 References
ANZG 2018. Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and
New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.
ANZECC/ARMCANZ. 2000. Australian and New Zealand Guidelines for Fresh and Marine Water Quality.
Australian and New Zealand Environment and Conservation Council and Agriculture and Resource
Management Council of Australia and New Zealand.
DES. 2019. Environmental Protection (Water & Wetland Biodiversity) Policy 2019. Department of
Environment and Science, Queensland Government. Brisbane, Queensland, Australia.
DEHP. 2013. Queensland Water Quality Guidelines 2009, Version 3. Department of Environment and
Heritage Protection. Brisbane, Queensland, Australia.
DES. 2022. Noosa River environmental values and water quality objectives. Department of Environment
and Science (DES), Queensland Government.
DES. 2018. Monitoring and Sampling Manual 2018, Version 2 June 2018. Department of Environment and
Science. Brisbane, Queensland, Australia.
Government of Western Australia. 2011 (Amended 2015). Cone of Depression. Department of Water and
Environmental Regulation. Accessed 11 June 2024, https://www.der.wa.gov.au/your‐environment/acid‐
sulfate‐soils/66‐cone‐of‐depression.
NHMRC. 2018. Guidelines for Managing Risks in Recreational Water. Australian Government, National
Health and Medical Research Council.
PTG Consulting. 28 June 2024. Geotechnical Investigation Report, Proposed Residential Development, 25
Wyuna Drive, Noosaville. Ref: PTG/00259 – 0001–Rev0.
SCG Consulting Engineers. May 2024. Operational Works for Residential Development, Lot 12 on N10576,
25 Wyuna Drive, Noosaville. Ref: SCG‐0282‐CD, Issue 1. particularly Drawing 0282 ‐OW3.1 (Refer to
Appendix C).
ADG1673.24 Dewatering Management Plan_Rev0_12.07.24 Page 21
Page 47
ADG Consulting Pty Ltd
Appendix A: Figures
Figure 1 Site and proposed monitoring locations
ADG1673.24 Dewatering Management Plan_Rev0_12.07.24
Page 48
Figure 1 - Site and proposed monitoring locations (to be confirmed) A product of
Lot 12 on N10576, 25 Wyuna Drive, Noosaville, QLD
26°23'33"S 153°4'33"E 26°23'33"S 153°4'54"E
Legend located on next page
0 50 metres
Scale: 1:1927
Printed at: A3
Print date: 11/7/2024
Not suitable for accurate measurement.
Projection: Web Mercator EPSG 102100 (3857)
For more information, visit https://qldglobe.information.qld.gov.au/help-info/Contact-
us.html
Includes material © State of Queensland 2024. You are responsible for ensuring that
the map is suitable for your purposes. The State of Queensland makes no
representation or warranties in relation to the map contents and disclaims all liability.
If imagery is displayed, imagery includes material © CNES reproduced under license
from Airbus DS, all rights reserved © 21AT © Earth-i, all rights reserved, © Planet Labs
PBC, 2023
26°23'47"S 153°4'33"E 26°23'47"S 153°4'54"E Department of Resources
Page 49
ADG Consulting Pty Ltd Appendix B: DRDMW licenced bore search ADG1673.24 Dewatering Management Plan_Rev0_12.07.24
Page 50
DRDMW Licensed Bore Search A product of
200 m radius
26°23'30"S 153°4'28"E 26°23'30"S 153°5'3"E
Legend located on next page
0 100 metres
Scale: 1:3212
Printed at: A3
Print date: 11/7/2024
Not suitable for accurate measurement.
Projection: Web Mercator EPSG 102100 (3857)
For more information, visit https://qldglobe.information.qld.gov.au/help-info/Contact-
us.html
Includes material © State of Queensland 2024. You are responsible for ensuring that
the map is suitable for your purposes. The State of Queensland makes no
representation or warranties in relation to the map contents and disclaims all liability.
If imagery is displayed, imagery includes material © CNES reproduced under license
from Airbus DS, all rights reserved © 21AT © Earth-i, all rights reserved, © Planet Labs
PBC, 2023
26°23'54"S 153°4'28"E 26°23'54"S 153°5'3"E Department of Resources
Page 51
DRDMW Licensed Bore Search
200 m radius
Legend Attribution
Maxar
Registered water bores Roads and tracks
Includes material © State of Queensland (Department of Resources); ©
[RDMW and private] Motorway Commonwealth of Australia (Geoscience Australia); © 21AT, © Earth-i, all rights
Artesian bore reserved, 2024.
Highway
Artesian bore © State of Queensland (Department of Resources) 2023
Secondary
(abandoned but useable)
© State of Queensland (Department of Resources) 2024
Connector
Artesian bore
(abandoned and Local © State of Queensland (Regional Development, Manufacturing and Water) 2022
destroyed) This data were created by Geoscience Australia and are subject to
Restricted Access Road
Artesian bore, ceased to Commonwealth of Australia Copyright.
flow Mall
Artesian bore, ceased to Busway
flow (abandoned but
Bikeway
useable
Restricted Access
Artesian bore, ceased to
Bikeway
flow (abandoned and
destroyed) Walkway
Sub-artesian facility Restricted Access
Walkway
Sub-artesian facility
(abandoned but useable) Non-vehicular Track
Sub-artesian facility Track
(abandoned and
Restricted Access Track
destroyed)
Ferry
Surface water facility
Proposed Thoroughfare
Surface water facility
(abandoned but useable)
[Deprecated] Railway
Surface water facility station
(abandoned and
destroyed)
Places: Land parcel
Site - Lot 12 on N10576
Places: My Places(1)
My Place 1
Green bridges
Bridges
Tunnels
[Deprecated] Railway
Page 52
ADG Consulting Pty Ltd Appendix C: Operational Works ‐ Drawing 0282 ‐OW3.1 ADG1673.24 Dewatering Management Plan_Rev0_12.07.24
Page 53
THE SITE
Issue:
SCG HOLDINGS PTY LTD T/A
Unit 1/11 Project Ave,
Noosa Heads
Ph (07) 5455 5604
email:[email protected]
web:www.scg-engineers.com
ABN 68 669 675 790
Title:
Project
Date: Drawn Design
Checked: Drg No. Rev.
Rev. - 10.06.16
Page 54
–
·
‘ ’
·
·
·
·
·
·
·
·
·
·
Issue:
Unit 1/11 Project Ave,
Noosa Heads
Ph (07) 5455 5604
DEBUILD T/A
email:[email protected]
web:www.scg-engineers.com
ABN 40 098 481 899
Title:
Project
Date: Drawn Design
Checked: Drg No. Rev.
Rev. - 10.06.16
Page 55
Issue:
SCG HOLDINGS PTY LTD T/A
Unit 1/11 Project Ave,
Noosa Heads
Ph (07) 5455 5604
email:[email protected]
web:www.scg-engineers.com
ABN 68 669 675 790
Title:
Project
Date: Drawn Design
Checked: Drg No. Rev.
Rev. - 10.06.16
Page 56
Issue:
SCG HOLDINGS PTY LTD T/A
Unit 1/11 Project Ave,
Noosa Heads
Ph (07) 5455 5604
email:[email protected]
web:www.scg-engineers.com
ABN 68 669 675 790
Title:
Project
Date: Drawn Design
Checked: Drg No. Rev.
Rev. - 10.06.16
Page 57
1.73
1.
Issue:
SCG HOLDINGS PTY LTD T/A
Unit 1/11 Project Ave,
Noosa Heads
Ph (07) 5455 5604
email:[email protected]
web:www.scg-engineers.com
ABN 68 669 675 790
SITE PREPARATION & EARTHWORKS Title:
DILAPIDATION REPORT: Project
Date: Drawn Design
Checked: Drg No. Rev.
Rev. - 10.06.16
Page 58
RESIDENTIAL
DEVELOPMENT
Issue:
SCG HOLDINGS PTY LTD T/A
Unit 1/11 Project Ave,
Noosa Heads
Ph (07) 5455 5604
email:[email protected]
web:www.scg-engineers.com
ABN 68 669 675 790
Title:
Project
Date: Drawn Design
Checked: Drg No. Rev.
Rev. - 10.06.16
Page 59
Issue:
SCG HOLDINGS PTY LTD T/A
Unit 1/11 Project Ave,
Noosa Heads
Ph (07) 5455 5604
email:[email protected]
web:www.scg-engineers.com
ABN 68 669 675 790
Title:
Project
Date: Drawn Design
Checked: Drg No. Rev.
Rev. - 10.06.16
Page 60
RESIDENTIAL
DEVELOPMENT
Issue:
SCG HOLDINGS PTY LTD T/A
Unit 1/11 Project Ave,
Noosa Heads
Ph (07) 5455 5604
email:[email protected]
web:www.scg-engineers.com
ABN 68 669 675 790
PLUMBING ARTICULATION:
Title:
Project
Date: Drawn Design
Checked: Drg No. Rev.
Rev. - 10.06.16
Page 61
ADG Consulting Pty Ltd Appendix D: Dewatering calculation output ADG1673.24 Dewatering Management Plan_Rev0_12.07.24
Page 62
Input Length of excavation: |20 | metres Width of excavation | 18 | metres Drawdown required: | 18 | metres Aquifer thickness”) | 10 | metres Hydraulic conductivity: lo 0000949 | metres/second Calculate Results Effective pumping radius, Re: 11 metres Cone of depression radius, Ro : 53 metres litres/second oO Total pumping rate: Pumping time required: 44 hours
Page 63
SCG Consulting Engineers
REFERENCE DOCUMENT
OPW24/0098 ABN 68 669 675 790
NOOSA COUNCIL
6 August 2024 25 SEPTEMBER 2024
Unit 1/11 Project Avenue,
SCG Ref: 0282(L1) Noosaville QLD 4566
By email: [email protected] P: 07 5455 5604
E: [email protected]
Wyuna Drive P/L TTE
PO Box 1661,
C/- Pivotal Perspective Pty Ltd Noosa Heads QLD 4567
scg-engineers.com
Dear Sir/Madam
Re: OPW24/0098 ~ Lot 12 N 10576, 25 Wyuna Drive, Noosaville
We have reviewed Noosa Council’s request for information dated 29 July 2024 and provide our response to the
Engineering related items.
Issue:
The submitted Geotechnical Investigation Report does not fully address the potential for acid
sulfate soils or groundwater and section 8 of the report provides preliminary comments only.
Information Required
3. Provide an amended Geotechnical Investigation Report that includes site specific
recommendations to address/control the sites potential for acid sulfate soils and
groundwater.
Response
Please see attached letter from the geotechnical engineer. The existing dwelling restricts access for a drilling rig
to conduct testing in further locations, as the dwelling is currently occupied it is nonviable for the client to demolish
the existing dwelling (leaving the site vacant) prior to development approval and detailed building design. Further
testing has been commissioned and we request this information be conditioned prior to any earthworks
commencing on site.
Issue:
Council has concerns with the potential for the proposed works to impact on the groundwater levels in the
area and impact on the structural integrity of building and structures on the adjoining properties.
Information Required
5. Provide a report that is prepared by a suitably qualified person that considers the potential impacts
of the proposed works on the groundwater levels in the area and includes recommendations to
maintain the structural integrity of building and structures on the adjoining properties
Response
The dewatering methodology proposed will consist of dewatering spears installed to the inside the proposed
concrete piled retention (cut-off) wall this will generally maintain groundwater levels outside the proposed piling
Document Set ID: 23180013
Version: 1, Version Date: 14/08/2024
Page 64
walls to existing levels resulting in minimal drawdown of the water table outside the excavation footprint.
Dilapidation reports for both neighbouring properties will be completed prior to works commencing.
Further, existing neighbouring sites are already subject to significant tidal variations including king tides albeit with
a slightly dampened response. Therefore, the likelihood of additional impacts from construction dewatering is
considered unlikely.
If you require any further information, please do not hesitate to contact our office.
Yours faithfully
TOM HARRINGTON – RPEQ 27698
For and on behalf of
SCG CONSULTING ENGINEERS
Enc PTG Consulting Letter reference: PTG/00259-0002-Rev0
SCG Consulting Engineers Page 2 of 2 SCG Ref:0282(L1)
Document Set ID: 23180013
Version: 1, Version Date: 14/08/2024
Page 65
REFERENCE DOCUMENT
OPW24/0098
NOOSA COUNCIL
25 SEPTEMBER 2024 Page 1 of 1
25 Wyuna Drive, Noosaville Page 1 of 1 31 July 2024
Document Set ID: 23180013
Version: 1, Version Date: 14/08/2024