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RFI - ADG1451.22 Dewatering Management Plan_Rev0_28.02.23
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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
Dewatering Management Plan
Proposed Residential Development:
Lots 2 & 3 on MCH3881, 130‐132 Gympie Terrace, Noosaville, Queensland
February 2023
Prepared for:
Craig & Nathan Francis
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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Report details
Project ref: ADG1451.22
ADG Project Contact: Michael Campbell
Report title: Dewatering Management Plan
Proposed Residential Development:
Lots 2 & 3 on MCH3881, 130‐132 Gympie Terrace, Noosaville, Queensland
Version: Rev0
Author(s): ADG
Reviewer: Michael Campbell
Client: Craig & Nathan Francis
c/‐ SCG Consulting Engineers
Client contact: Tom Harrington – SCG Consulting Engineers
Distribution date: 28 February 2023
Distributed to: SCG Consulting Engineers
Copies: 1 PDF
ADG Consulting Pty Ltd
Michael Campbell BEnvSc, BSc[Hons],
DipProjMgt, DipOHS, DipBusMgt, DipBus(Quality Auditing)
MEIANZ, MALGA, MASSI
Director & Principal Environmental Scientist
Date: 28 February 2023
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 PACIFIC GEOTECH PTY LTD 2022 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 9
5.1 BASEMENT EXCAVATION AND SHORING 9
5.2 GROUNDWATER EXTRACTION 9
5.3 EXTRACTION/DISCHARGE RATES AND VOLUME 9
5.3.1 DEWATERING EXTRACTION CALCULATION BASED ON SUBSURFACE SOIL PROFILE 9
5.4 DEWATERING DURATION 10
5.5 GROUNDWATER DRAWDOWN 10
5.6 GROUNDWATER TREATMENT 11
5.7 NOMINATED HOLD POINTS 11
6 WATER QUALITY MANAGEMENT 12
6.1 RESPONSIBILITY 12
6.2 OPERATIONAL POLICY 12
6.3 PERFORMANCE CRITERIA 12
6.4 IMPLEMENTATION STRATEGY 12
6.4.1 GROUNDWATER TREATMENT SYSTEMS 12
6.4.2 DEWATERING STRATEGY 13
6.4.3 INITIAL PUMP‐OUT 13
6.5 MONITORING 13
6.5.1 VISUAL MONITORING 13
6.5.2 WATER QUALITY MONITORING 13
6.5.3 MONITORING RESPONSIBILITIES 14
6.6 MAINTENANCE 15
6.7 REPORTING 15
6.8 CONTINGENCIES 15
7 NOISE & ODOUR MANAGEMENT 17
7.1 RESPONSIBILITY 17
7.2 OPERATIONAL POLICY 17
7.3 PERFORMANCE CRITERIA 17
7.4 IMPLEMENTATION STRATEGY 17
7.4.1 NOISE 17
7.4.2 ODOUR 17
7.5 MONITORING 17
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7.6 REPORTING 18
7.7 CONTINGENCIES 18
8 LIMITATIONS 19
9 REFERENCES 20
APPENDIX A: FIGURES
APPENDIX B: DRDMW LICENCED BORE SEARCH
APPENDIX C: BASEMENT INSTALLATION PLAN (DRAFT)
APPENDIX D: DEWATERING CALCULATION OUTPUT
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1 Introduction
ADG Consulting Pty Ltd (ADG) was engaged by Craig & Nathan Francis care of SCG Consulting Engineers
(SCG) to prepare a Dewatering Management Plan (DMP) for the proposed residential development within
property described as Lots 2 & 3 on MCH3881, situated at 130‐132 Gympie Terrace, Noosaville,
Queensland.
1.1 Proposed development
The proposed development comprises the construction of four two‐storey residential dwellings (2x
duplex pairs) overlying two single level in‐ground basements on the 1,581 m2 site. Supplied information
indicates that excavations to facilitate the basement construction will extend to a maximum of
approximately 2.3 m below ground level (bgl) to approximately ‐0.7 m Australian Height Datum (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 depths pf between 1.0 to 1.1 mbgl (equating to an approximate
elevation of 0.6 m AHD), during preliminary geotechnical works (drilling) on the site by Pacific Geotech in
October 2022. Given the sites proximity to the 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 Lots 2 & 3 on MCH3881, and is situated at 130‐132 Gympie Terrace, Noosaville,
Queensland. From most recent available aerial mapping dated 24 November 2022 (Nearmap), the site
has been cleared of aboveground infrastructure (circa June‐July 2022) and is generally square to
trapezoidal in shape. The site has a combined area of 1,581 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 Chaplin Park, then Noosa River.
East 2‐ storey residential lots, then canal network associated with Noosa River.
South Gympie Terrace, then multiple residential lots.
West Cleared vacant land, then residential lot, then Mill Street.
2.3 Topography
The site and surrounding land is considered to be generally level (PG, 2022), with the site surface
elevations ranging between approximately 1.3 m to 1.8 m AHD from the southern boundary toward the
north of the site (refer SCG earthworks and piling plan).
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, 28 February 2023).
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, 28 February 2023).
2.5 Hydrogeology
A search of groundwater bores licensed by DRDMW was conducted by ADG on 28 February 2023. 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 and/or east. Groundwater beneath the site is likely to be hydraulically
connected to the river and/or canal network, 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:
Acid Sulfate Soil Investigation, Proposed Residential Development, 128 – 132 Gympie Terrace,
Noosaville. November 2022. Pacific Geotech Pty Ltd. Ref: PG‐9236, 2022‐10‐31, ASR VER 1.
Geotechnical Investigation, Proposed 128 – 132 Gympie Terrace, Noosaville. November 2022. Pacific
Geotech Pty Ltd. Ref: PG‐9236, 2022‐11‐08, GR VER 1.
Operational Works: Earthworks & Piling – 130 – 132 Gympie Terrace, Noosaville. Drawing No. 32225‐
OW3.1. September 2022. SCG Consulting Engineers Pty Ltd.
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 Pacific Geotech Pty Ltd 2022
A Geotechnical Investigation and concurrent Acid Sulfate Soils Investigation was undertaken at the site
in October 2022 (reported November 2022) by Pacific Geotech Pty Ltd (PG).
3.1.1 Soils
A total of four (4) boreholes (BH01 to BH04) were drilled on the proposed development footprint to
between 4.0 and 9.0 mbgl.
The subsurface profile encountered is generally described as clay and sand fill material at the ground
surface, extending to depths ranging between 1.0 m and 1.1 m. Fill material is underlain by natural sand
and silty sand which is initially medium dense, becoming loose with depth, extending to depths ranging
between 2.5 m and 2.9 m. The upper‐level sand is underlain by very dense, indurated sand which extends
to depths ranging between 2.8 m and 3.2 m. This indurated sand is underlain by stiff to hard, silty and
sandy clay, which extends to the borehole termination depths.
Alongside the Geotechnical Investigation (2021), Acid Sulfate Soil (ASS) samples were collected at 0.5 m
intervals in BH01 & BH02 to 4.0 m depth. A total of sixteen (16) samples were collected for ASS screening
and eight (8) samples were selected for further analysis by the Chromium Reducible Sulfur suite (CRS).
ADG notes that the testing was limited to two boreholes with ASS testing to 4.0 m depth, and PG reports
that within part of this depth profile the natural sands are considered to contain potential ASS requiring
liming at rates of up to 8 kg/tonne. All excavated spoil from depths between 1.5 to 2.5 mbgl within the
excavation footprint will be appropriately neutralised with lime and validated in accordance with
recommendations by PG in the ASS Investigation Report (PG, 2022).
3.1.2 Groundwater
During drilling activities for the Preliminary Geotechnical Investigation, groundwater seepage/inflow was
encountered at 1.0 to 1.1 m depth below the ground surface (approx. 0.6 m AHD)(PG, 2022).
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 canal to the east and river to the north, albeit somewhat a dampened
response to tidal variations.
3.2 Groundwater quality
No groundwater quality data was obtained by PG as part of the preliminary geotechnical investigation.
However, based on numerous groundwater investigations and dewatering monitoring projects that have
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been undertaken by ADG throughout the Noosa Coast Region in recent years, our understanding of the
groundwater quality in the region is provided below:
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 to the stormwater network via gully pit on Gympie
Terrace (adjacent the bus stop) which discharges to the canal network associated with the Noosa River
located approximately 60 m east of the 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, marine canal
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 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.
Table 3 Receiving waters criteria
Parameter Criteria
Physico‐chemical
pH (pH units) 7.8 – 8.31
Dissolved oxygen (% saturation) 85 – 1051
Suspended solids (mg/L) ≤141
Turbidity (NTU) ≤81
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
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Parameter Criteria
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 (canal).
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
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 design
at Appendix C). Excavations to facilitate the construction of the basement will extend to approximately
2.3 m below ground level, which corresponds to a maximum elevation of ‐0.7 m AHD. Localised deeper
excavations may be required for construction of other structural elements (i.e. footings & pile caps).
All excavated spoil from depths between 1.5 to 2.5 mbgl within the excavation footprint will be
appropriately neutralised with lime and validated in accordance with recommendations by PG in the ASS
Investigation Report (PG, 2022).
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
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 2.3 m to around ‐1.7 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 = 35 m
Approximate width of excavation = 30 m
Reduction in depth of groundwater across the basement footprint/excavation = 2.3 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) 18
Dewatering radius of influence (m) 67
Discharge rate (L/sec) 9
Discharge rate (L/hr) 32,400
Establishment of cone of depression (hours) 76
Based on the above inputs, a groundwater flow rate of approximately 9 L/sec or 540 L/min or 32,400 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 6 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 10 to 12 L/sec, as a contingency against higher than anticipated
flow rates exceeding the estimated 6 to 9 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 10 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 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 10 to 12 L/sec, as a contingency against
higher than anticipated flow rates exceeding the estimated 6 to 9 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 nine 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 32,400 L/hr (equivalent 540 L/min) from Section 5.3.1 of
this Report, one sedimentation tank will provide approximately forty‐two 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.
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
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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.
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.
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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.
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 Craig & Nathan Francis 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 Craig & Nathan Francis 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.
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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.
DNRME. 2002. Redcliffe to Teewah – Map 2 1:25,000. Queensland Department of Natural Resources and
Mines. Brisbane, Queensland, Australia.
Government of Western Australia. 2011 (Amended 2015). Cone of Depression. Department of Water and
Environmental Regulation. Accessed 28 February 2023, 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.
Noosa Shire Council. Noosa Council Interactive Mapping, Stormwater Infrastructure. Accessed 28
February 2023.
https://enterprise.mapimage.net/IntraMaps910/?project=Public&module=Property%20Recreation%20
Utilities&configId=64251f07‐9411‐4a61‐930e‐2bd9b45d8fff&startToken=8fb07456‐4db7‐45a7‐89df‐
64e9b5a76aff&touch=false
Pacific Geotech Pty Ltd. November 2022. Acid Sulfate Soil Investigation, Proposed Residential
Development, 128 – 132 Gympie Terrace, Noosaville. Ref: PG‐9236, 2022‐10‐31, ASR VER 1.
Pacific Geotech Pty Ltd. November 2022. Geotechnical Investigation, Proposed 128 – 132 Gympie Terrace,
Noosaville. Ref: PG‐9236, 2022‐11‐08, GR VER 1.
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Appendix A: Figures
Figure 1 Site and proposed monitoring locations
ADG1451.22 Dewatering Management Plan_Rev0_28.02.23
Page 26
Figure 1 - Site and proposed monitoring locations A product of
Lots 2 & 3 on MCH3881, 130-132 Gympie Terrace, Noosaville, QLD
26°23'47"S 153°3'4"E 26°23'47"S 153°3'25"E
Legend located on next page
0 50 metres
Scale: 1:1945
Printed at: A3
Print date: 28/2/2023
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 2023. 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°24'2"S 153°3'4"E 26°24'2"S 153°3'25"E Department of Resources
Page 27
Figure 1 - Site and proposed monitoring locations
Lots 2 & 3 on MCH3881, 130-132 Gympie Terrace, Noosaville, QLD
Legend Attribution
Includes material © State of Queensland (Department of Resources); ©
Registered water bores [RDMW Places: My Places Commonwealth of Australia (Geoscience Australia); © 21AT, © Earth-i, all rights
and private] reserved, 2023.
Site Discharge
© State of Queensland (Department of Resources) 2021
Artesian bore Receiving Waters (TBC)
Artesian bore (abandoned but © State of Queensland (Regional Development, Manufacturing and Water) 2021
Background Waters tide
useable) dependent (TBC) © State of Queensland (Department of Resources) 2022
Artesian bore (abandoned and Background Waters tide
destroyed) dependent (TBC)
Artesian bore, ceased to flow
Cities and Towns
Artesian bore, ceased to flow
(abandoned but useable
Road Crossing
Artesian bore, ceased to flow
(abandoned and destroyed) Bridge
Sub-artesian facility Tunnel
Sub-artesian facility (abandoned
Road
but useable)
Sub-artesian facility (abandoned Highway
and destroyed) Main
Surface water facility Local
Surface water facility (abandoned Private
but useable)
Surface water facility (abandoned
and destroyed)
Places: Land parcel
2MCH3881
3MCH3881
Railway
Page 28
ADG Consulting Pty Ltd Appendix B: DRDMW licenced bore search ADG1451.22 Dewatering Management Plan_Rev0_28.02.23
Page 29
DRDMW Licensed Bore Search A product of
500 m radius
26°23'46"S 153°3'2"E 26°23'46"S 153°3'26"E
Legend located on next page
0 50 metres
Scale: 1:2256
Printed at: A3
Print date: 28/2/2023
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 2023. 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°24'3"S 153°3'2"E 26°24'3"S 153°3'26"E Department of Resources
Page 30
DRDMW Licensed Bore Search
500 m radius
Legend Attribution
Includes material © State of Queensland (Department of Resources); ©
Registered water bores [RDMW Road crossing Commonwealth of Australia (Geoscience Australia); © 21AT, © Earth-i, all rights
and private] reserved, 2023.
Bridge
© State of Queensland (Department of Resources) 2021
Artesian bore Tunnel
Artesian bore (abandoned but © State of Queensland (Regional Development, Manufacturing and Water) 2021
useable)
Road
© State of Queensland (Department of Resources) 2022
Artesian bore (abandoned and Highway
destroyed) Main
Artesian bore, ceased to flow Local
Private
Artesian bore, ceased to flow
(abandoned but useable
Cities and Towns
Artesian bore, ceased to flow
(abandoned and destroyed)
Sub-artesian facility Railway
Sub-artesian facility (abandoned
but useable)
Sub-artesian facility (abandoned
and destroyed)
Surface water facility
Surface water facility (abandoned
but useable)
Surface water facility (abandoned
and destroyed)
Places: Land parcel
2MCH3881
3MCH3881
Places: My Places
200 m radius
Page 31
ADG Consulting Pty Ltd Appendix C: Basement Installation Plan (Draft) ADG1451.22 Dewatering Management Plan_Rev0_28.02.23
Page 32
DRAWING SIZE — At
HEIGHT DATUM
LOT 2 & 3 ON MCH3881
Level Datum AHD iI
Level Origin PM 105735, RL 4.577
Gympie Tce, Noosaville
Survey information provided by
Max Watterson & Associates
SITE _DEWATERING
— THE SITE IS TO BE CONSTANTLY DE-WATERED UNTIL THE GROUND
LEVEL SUSPENDED SLAB IS POURED.
— THE DESIGN AND INSTALLATION OF THE DEWATERING SYSTEM IS TO
BE BY A SPECIALIST CONTRACTOR.
—APPROX GROUND WATER TABLE OF 1.0m BELOW EXISTING GROUND
LEVEL. SEASONAL & TIDAL VARIATIONS NOT CONSIDERED
—GIVEN THE CLOSE PROXIMITY TO THE NOOSA RIVER, GROUNDWATER
LEVELS WILL VARY WITH TIDAL INFLUENCE AND PREVAILING WEATHER
CONDITIONS.
—EXTRACTED GROUNDWATER IS TO BE TREATED IN ACCORDANCE WITH
RECOMMENDATIONS PROVIDED IN A FUTURE DEWATERING MANAGEMENT
PLAN & SITE GEOTECHNICAL REPORT
— TREATED EXTRACTED GROUNDWATER IS TO BE DIRECTED TO COUNCIL
STORMWATER, FINAL OUTLET LOCATION TO BE APPROVED BY NOOSA
COUNCIL.
— PUMPING MUST NOT CAUSE NUISANCE FOR NIEGHBOURS. ENCLOSING
WITHIN A SOUND PROOF ENCLOSURE MUST BE CONSIDERED.
TEMPORARY CFA PILED RETAINING WALLS
— CFA PILED RETAINING WALL DESIGN AND INSTALLATION
BY A SPECIALIST CONTRACTOR
— DRIVING OF PILE WALLS NOT PERMITTED
— INSTALLATION OF GROUND ANCHORS INTO NEIGHBORING
PROPERTIES NOT PERMITTED WITHOUT OWNERS CONSENT
— ADDITIONAL MEASURES SUCH AS GROUTING THE JOINTS
IS RECOMMENDED TO REDUCE GROUNDWATER INFLOWS.
— PROVIDE GROUND MONITORING/VIBRATION CONTROL
DURING INSTALLATION.
— ESTABLISH SURVEY MONITORING POINTS ALONG PILED
WALL TO MONITOR WALL ALIGNMENT/ GROUND MOVEMENT
ESTABLISH SURVEY MOITORING POINTS ALONG PILE WALL
CAPPING BEAM TO MONITOR WALL ALIGNMENT/GROUND
MOVEMENT, PILING CONTRACTORS ENGINEER TO BE ADVISED OF
ANY OBSERVED MOVEMENT
EXISTING STRUCTURE /DWELLING
INCLUDING NEIGHBOURING
ALLOTMENTS
THE BUILDER /CONTRACTOR
SHALL CONFIRM ALL
RELEVANT LEVELS PRIOR 10
COMMENCING WORKS.
Ground /
pad level
UNSTABLE
&
Mey A
THIS FOOTING IS FOUNDED X
BELOW CRITICAL DEPTH ER Lo
LINE AND IS STABLE. STABLE NG
PIERS OR UNDERPINNING FOUNDED
BELOW THE CRITICAL DEPTH LINE
WOULD BE NEEDED TO SUPPORT
I
t
1 THIS FOOTING WITHOUT
t_ PIERS IS FOUNDED
ABOVE CRITICAL DEPTH
LINE AND IS UNSTABLE.
LINE OF PROPOSED
TRENCH.
EX. SWPT EXISTING STORMWATER PIT
ANY FOOTING THAT IS FOUNDED
ABOVE THE CRITICAL DEPTH LINE. Horizontal 30 De
CRITICAL DEPTH LINE
{
!
\
{
|—— EXCAVATION OR OTHER
{
!
\
ees
NOTE:
THIS DETAIL ALSO APPLIES TO EXISTING
FOUNDATIONS ON NEIGHBOURING
PROPERTIES. SHEET PILING MUST BE
INSTALLED WHERE EXISTING FOOTINGS WILL
BE FOUNDED ABOVE ANY EXCAVATION
CRITICAL DEPTH LINE
LEGEND
_---77 INDICATES PROPOSED SURFACE
18.07
+100
YD
FILL (POSITIVE) AS NOTED
INDICATES AREA OF CUT
INDICATES AREA OF FILL
INDICATES POSITION OF TEMPORARY
SHORING, DESIGN AND INSTALLATION BY
SPECIALIST CONTRACTOR
— E — INDICATES OVERHEAD ELECTRICITY
SUPPLY LINE
INDICATES EXISTING SEWER LINE
w———_ INDICATES WATER MAIN APPROX
CONTOURS AND LEVELS TO AHD.
EXISTING SURFACE SPOT LEVELS.
INDICATES DEPTH OF CUT (NEGATIVE) OR
ALIGNMENT, BUILDER TO CONFIRM EXACT
LOCATION PRIOR TO WORKS
| ——___ INDICATES TELSTRA LINE APPROX
ALIGNMENT, BUILDER TO CONFIRM EXACT
LOCATION PRIOR TO WORKS
AS NOTED
INDICATES STORMWATER DRAIN EXISTING
INDICATES POSITION OF RETAINING WALL
www.dialbeforeyoudig.com.au
SS DIAL 1100
yy BEFORE YOU DIG
TO STRUCTURAL ENGINERS DETAIL.
BUILDER TO MAINTAIN STABILITY
OF ALL NEIGHBOURING STRUCTURES,
REFER CRITICAL DEPTH LINE DETAIL
ON THIS SHEET
Soo BASEMENT WALLS TO STRUCTURAL FINAL BASEMENT SLAB THICKNESS TO
z | ENGINEERS DETAIL BE DETAILED BY STRUCTURAL K
we | ENGINEER
=|8
ae! PAVEMENT AS EX: SMH
“FE ? RAFT SLAB 10 Ore ON ORS COB.
I STRUCTURAL Ka&c
I ENGINEERS DETAIL.
i| NSLL.
5 FH.
ly ay
2 TP
a Ee FPL AS a EP.
“ez FPL AS NOMINATED. S KERB
| “ a NOMINATED. S RCEW
7/7 S.V
_ Vy CLL YY Y t W.M
CL
CL 7
eR TANKING WATERPROOF BLANKET WITH
PRIMER & PROTECTIVE COATING INSTALLED
BY SPECIALIST CONTRACTOR TO DRIVEWAY / CARPARK PAVEMENT
MANUFACTURERS’ SPECIFICATIONS &
CERTIFICATION.
FINISHED LEVELS. DIAGRAM FINISHED LEVELS DIAGRAM
TYPICAL SECTION
TYPICAL SECTION
—— — “ip
+ Lp —_—__ : -
«CHAPLAIN PARK |
———— 7 : /s , . ae _ /
ae
6] POOL Oo
EXCAVATION
TOP : 2.10 vo) ba | EXCAVATION TOP : 2.10
BTM : 1.65 + ob Re ye -0.828 | BTM : 1.45
= 0.45m aM T0651 H = 0.65m
7 5 } !
= 0.670] |
0.584 page — ~2-——=-+----- 4 =2.124
Ne ae 1 a -grc tron | INDICATES CFA CONCRETE PILING OR SIMILAR, DESIGN AND
ENSURE 600mm MIN. BEHIND 12.218 i \* | * #” [-2140; | INSTALLATION BY OTHERS. MINIMUM VIBRATION TECHNIQUES TO
PILING TO ALLOW FOR | | SN | | | BE USED FOR INSTALLATION, VIBRATION CONTROL AND
ACCESS FOR BASEMENT |: | | va | |—— MANAGEMENT BY PILING CONTRACTOR. BUILDER TO CONFIRM
WALL WATERPROOFING. | I >< an iN | EXTENT REQUIRED TO SATISFY CRITICAL DEPTH LINE
TYPICAL, 600mm _ MIN. | MN Le _ PROTECTION | oF NEIGHBOURING STRUCTURES.
ct | ‘. a7 \ 5
H S71 + . |
| | ‘¢ iE a f
! | RESIDENTIAL ~
mee | DEVELOPMENT N
0.511 Ai | Ny ESTABLISH SURVEY MOITORING POINTS ALONG PILE WALL
I FFL: —0.300 1 CAPPING BEAM TO MONITOR WALL ALIGNMENT/GROUND
| Sp . . | _ [MOVEMENT, PILING CONTRACTORS ENGINEER TO BE ADVISED OF
| FPL: —0.700 ; LAN oBsERVED MOVEMENT
om | 1 > ! | |
TOP : 2.10 | OK 2.296 -2.200}! 0.600] | TOP: 2.10
BIM : 1.80 i | ARS ag 0 | |BIM : 1.55
= 0.30m \ | | \ , A ex A: * | / H = 0.55m
| AK |
L-~ ! af DASHED LINE INDICATES 1\ Bf TOP : 2.50
TOP : 250 [> goo LF —7.300 aa #° PROPOSED BUILDING | BM : 1.50
BIM : 1.70 : 1 ! i Za FOOTPRINT MK 4 H = 1.00m
= 0.80 ‘a
m jo | 4
4 6 —_\ Ub
+ j | + 7 | #
8 a | |
1 ye | i
! ve + :
TOP : 2.30 I 8 14-9949 | |
BTM : 1.50 ee 2.236
H = 0.80m 48 ]
__ [0.964 SRS TOP : 2.30
cr TI 764 Ot | BTM : 1.50
+ a ee DRIVEWAY 7H = 0.80m
01 REFER Drg. OW4.1 &
OW4.2 FOR DETAILS. |
TERRACE
SITE PLAN — EARTHWORKS & PILING PLAN
Scale 1: 200
PRIOR TO COMMENCING WORKS,
UNDERTAKE DILAPIDATION REPORTS OF
ALL NEIGHBORING DWELLINGS/STRUCTURES
ALL SERVICES SHOWN ON THIS PLAN INDICATIVE
ONLY CONTRACTOR TO LOCATE ALL SERVICES
PRIOR TO COMMENCING WORKS ON SITE. ALL
CONTRACTOR TO REPAIR ADJACENT THE
CONSTRUCTION SITE KERB, FOOTPATH OR
ROAD RESERVE IF ANY DAMAGE IS SUSTAINED
DURING CONSTRUCTION. GRASSED AREAS ARE
TO BE RE TOP SOILED AND TURFED.
SERVICES ARE TO BE PROTECTED IN
ACCORDANCE WITH THE AUTHORITY
RESPONSIBLE FOR THE SERVICE
NOTE:
CUT/FILL LEVELS SHOWN REPRESENT THE FINISHED PAD
LEVEL (FPL) TO THE UNDERSIDE OF THE GROUND BEARING
SLABS AND PAVEMENTS AND INCLUDES THE CRUSHER
DUST OR ROAD BASE LAYERS 10 BE PROVIDED UNDER THE
SLABS. ADDITIONAL LANDSCAPING FILL NOT INCLUDED.
SITE GEOTECHNICAL
INFORMATION/ RECOMMENDATIONS PRESENTED IN
A FUTURE GEOTECHNICAL INVESTIGATION REPORT
COMPLETED BY A GEOTECHNICAL ENGINEER.
DILAPIDATION REPORT:
PRIOR TO ANY CONSTRUCTION
UNDERTAKE DILAPIDATION REPORT OF ALL
NEIGHBORING DWELLINGS/ STRUCTURES.
RC PILES, DESIGN
BY OTHERS
EXCAVATION DEPTH
V
©O--
EXISTING SEWER MANHOLE
EXISTING SEWER CONNECTION POINT
EXISTING EDGE OF BITUMEN
EXISTING KERB & CHANNEL
NATURAL SURFACE LEVEL
FIRE HYDRANT
TELSTRA PIT
ELECTRICAL PILLAR
EXISTING KERBING
REINFORCED CONCRETE END WALL
STOP VALVE
WATER METER
EXISTING GROUND LEVEL
—_ Y
PILE DESIGN BY OTHERS
(OC) CONCRETE PILED RETAINING WALL
\ 7 SECTION
CONSTRUCTION NOTES
GENERAL:
1. DO NOT SCALE FROM THIS DRAWING.
2. ALL DIMENSIONS IN MILLIMETRES
3. SETTING OUT DIMENSIONS ARE TO BE OBTAINED FROM THE
ARCHITECTURAL DRAWINGS.
4. ANY DISCREPANCIES BETWEEN THESE DRAWING AND THE
ARCHITECTURAL DRAWINGS ARE TO BE REFERRED TO THE
ENGINEER IMMEDIATELY.
5. THE BUILDER IS RESPONSIBLE FOR LOCATING ALL EXISTING
SERVICES WITHIN AND ADJACENT THE ALLOTMENT AND SHALL
ENSURE THAT ALL NEW WORKS ARE IN ACCORDANCE WITH
THE ATTACHED CRITICAL DEPTH LINE DIAGRAM.
FILLING NOTES
—THE SITE IS TO BE SCRAPED CLEAR OF ALL ORGANIC
MATERIAL AND DEBRIS.
—THE SUBGRADE IS TO BE ROLLED WITH A VIBRATING STEEL
DRUM ROLLER TO ACHIEVE A MINIMUM RELATIVE FIELD
DENSITY OF 98%. THE COMPACTION IS TO BE SUFFICIENT TO
ACHIEVE A BLOW COUNT OF 7 BLOWS PER 300mm WITH AN
APPROVED PERTH SAND PENETROMETER FOR A DEPTH OF
1.0m BELOW EXCAVATED LEVEL. COPIES OF COMPACTION TEST
RESULTS SHALL BE PRESENTED TO SCG CONSULTING
ENGINEERS FOR APPROVAL.
—UNLESS NOTED OTHERWISE A MINIMUM BEARING CAPACITY
OF 100kPa SHOULD BE ACHIEVED WITHIN COMPACTED FILLING.
COMPACTION & BEARING CAPACITY TEST RESULTS MUST BE
PRESENTED TO SCG CONSULTING ENGINEERS FOR APPROVAL
PRIOR TO WORKS PROCEEDING.
—THE FILL MATERIAL CLEAN GRANULAR MATERIAL (I.E. SAND
TO A CLAYEY SAND IN ACCORDANCE WITH AS1726) BE FREE
OF ANY ORGANIC MATERIAL AND HAVE A CLAY CONTENT OF
LESS THAN 12% (PLASTICITY INDEX LESS THAN 25%, LINEAR
SHRINKAGE OF 15%). THE PROPOSED MATERIAL IS TO BE
INSPECTED BY SCG CONSULTING ENGINEERS PRIOR TO ITS
REMOVAL TO ENSURE ITS COMPATIBILITY.
—THE FILL IS TO BE PLACED AND COMPACTED IN
ACCORDANCE WITH AS3798-1996 TO A LEVEL SUFFICIENT TO
ACHIEVE A LEVEL 2 CERTIFICATION WITH A MINIMUM RELATIVE
FIELD DENSITY OF 98%. COPIES OF COMPACTION TEST
RESULTS SHALL BE PRESENTED TO SCG CONSULTING
ENGINEERS FOR APPROVAL.
FILLING AND COMPACTING ADJACENT EXISTING STRUCTURES
IS TO BE IN STRICT ACCORDANCE WITH THE ASSOCIATED
DETAILS AND SPECIFICATIONS.
—AREAS WHERE EXISTING STRUCTURES OR TREES ARE
REMOVED SHALL BE BACKFILLED WITH THE APPROVED FILL
MATERIAL COMPACTED IN ACCORDANCE WITH AS2870-1996 TO
ACHIEVE A MINIMUM RELATIVE FIELD DENSITY OF 987.
—ANY LOOSE OR SOFT MATERIAL UNCOVERED IN THE SITE
PREPARATION SHALL BE REMOVED AND REPLACED WITH THE
APPROVED FILL MATERIAL COMPACTED IN ACCORDANCE WITH
AS2870-1996 TO ACHIEVE A MINIMUM RELATIVE FIELD
DENSITY OF 98%.
—SITE DRAINAGE AND SILT PROTECTION MEASURES MUST BE
ISTALLED PRIOR TO CONSTRUCTION COMMENCING.
Revision | Description Date
“FOR APPROVAL
DO NOT SCALE FROM THIS DRAWING
The design and associated details contained on this and associated
drawings are copyright and are not to be used or reproduced without
the written permission of SCG Consulting Engineers.
Unit 1/11 Project Ave,
Noosa Heads
Ph (07) 5455 5604
email:[email protected]
web:www.scg-engineers.com
ABN 40 098 481 899
C) Ste
DEBUILD T/A
Title:
EARTHWORKS PLAN
Project
150-132 Gympie Tce,
Noosaville
Date: Sept 22 Drawe Design TH
_| Checked: Drg No. Re
15400 @ AS i SRicherdson |) | O2220 —OW3.1) .
Page 33
ADG Consulting Pty Ltd Appendix D: Dewatering calculation output ADG1451.22 Dewatering Management Plan_Rev0_28.02.23
Page 34
Cone of depression DER requires @ preliminary assessment of the radial extent of the cone of depression and pumping rates and times for all dewatering operations in ASS areas. Empirical methods to calculate the radial extent of the groundwater cone of depression and pumping rates and times for dewatering operations are outlined in Appendix E of @) Treatment and maenegement of soils and water in acid sulfate soil landscapes 1.59 MB (Published July 2011, Revised June 2015) Calculator Input Length of excavation 35 (metres): Width of excavation 30 (metres): Required groundwater 23 drawdown (metres): Saturated thickness of the, unconfined aquifer! (metres): Hydraulic conductivity of the aquifer (K) (metres per second): 0.0000949 4 = & Results Effective radius of pumping well, R. (metres): Radius of influence of dewatering, R, (metres): (i.e. radius of the cone of depression) Total pumping rate (litres per second): Time taken to establish the cone of depression (hours): m/sec 18m 67m 9l/sec 76hrs