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Introduction 1
1. Introduction
The City Rail Link (CRL) project comprises the construction, operation and maintenance of a 3.4 km underground passenger railway, running between Britomart Station and the North Auckland Rail Line (NAL) in the vicinity of Mt Eden Station. The CRL involves the construction of two new underground stations at Aotea and Karangahape, and a redeveloped station at Mt Eden (refer to Figure 1-1). The design and construction of the CRL infrastructure between the Aotea and Mt Eden Stations is being delivered by the Link Alliance.
This Flocculent Treatment Management Plan (FTMP) has been prepared in relation to the Mt Eden Enabling Works (“the Project”), particularly for the works undertaken within Mt Eden Construction Support Area (CSA).
Figure 1-1: CRL Route and Location
1.1 Overview of CRL works in Mt Eden
The CRL works in the Mt Eden area involve the construction of the southern section of the tunnel structures and the tie-in to the existing NAL, including the construction of the redeveloped Mt Eden Station. The Mt Eden Active Construction Zone (ACZ) and Construction Support Area (CSA4) is generally located between Nikau Street to the north, State Highway 1 (SH1) to the east, Dominion Road to the west and the existing NAL to the south.
The works in this area include:
Construction of an underground grade separation structure near Mt Eden Station; A new Mt Eden Station building incorporating passenger linkages; Modifications to the existing Mt Eden Station platforms; Road over rail bridges at Mt Eden Road, Normanby Road and Ruru Street with sections of road realignment;
Grade separation structures for the existing and new rail lines to pass-over and connect with each other; Pedestrian and cyclist bridge structures at Fenton Street and Porters Avenue; and New road linkages within the reinstated area post-construction.
Given the nature and scale of CRL works in Mt Eden, construction will be undertaken in a staged manner.
This FTMP relates to the first stage of these works (the Mt Eden Enabling Works), as described in Section 2 below.
Following completion of the Project, works in this area will involve:
Main construction works –these works will include: Tunnel Boring Machine (TBM) operations, structure construction and waterproofing/tanking for cut and cover tunnels, utilities installation, retaining wall for Ruru street extension, construction of the rail line tieins including junctions and grade separation structures, realignment of the existing Western Line including platform reconstruction, grade separation of Normanby Road, pedestrian / cyclist bridges at Fenton and Porters, construction of the new station buildings. The Main Works will be undertaken from Mid 2020 through to 2024. Public realm reinstatement –these works will involve establishing the final finishings and features that will comprise the completed Mt Eden Station and surrounds and will likely to be undertaken from 2021 to first quarter-2024.
1.2 Purpose of the Flocculent Treatment Management Plan (FTMP)
This FTMP has been prepared to identify measures that will be implemented to enhance the effectiveness of the erosion and sediment control measures utilised on site to mitigate and manage the potential adverse effects on water quality during the Mt Eden Enabling Works.
This FTMP also includes the Water Quality Discharge Monitoring Programme (WQDMP).
The objective of the FTMP is:
To manage all bulk earthworks to minimise any discharge of debris, soil, sediment or sediment-laden water beyond the site to either land and/or stormwater drainage systems. To detail how the discharges of water from the site will be monitored to ensure compliance with the above.
This FTMP addresses the requirements of the Aotea to North Auckland Line (A2N) resource consent and will be implemented throughout the construction period.
It is to be noted that the Mt Eden Enabling Works are to be undertaken within areas of varying degrees of contamination. As such the ability to discharge runoff generated by the works is also primarily regulated by compliance with the Contamination Delivery Work Plan (C DWP).
This FTMP has been prepared by McConnell Consultancy Ltd on behalf of the Link Alliance and forms part of the Construction Environmental Management Plan (CEMP) for the Project. It has been prepared in accordance with condition 59 of the A2N resource consent, in consultation with the Mt Eden Community and Business Liaison Group (CLG) prior to submission to Auckland Council (as per condition 19 of the A2N resource consent).
No construction activities will commence until certification of this FTMP has been received from Auckland Council (as per condition 60 of the A2N resource consent).
1.3 Associated management plans
The CEMP outlines the environmental management framework for the Project and details the relationship between the CEMP, environmental management plans, design certification requirements and the resource consent conditions. It also provides an overview of the management plans required by the conditions (their purpose and content etc.) and other environmental mitigation measures to be implemented during construction.
The CEMP also includes details of stakeholder management, training and roles and responsibilities.
Associated management plans that are particularly relevant to the implementation of this FTMP include:
C DWP Erosion and Sediment Control Plan (ESCP)
The ESCP is the overarching document which details the minimum standards and management practices to be used during the Mt Eden Enabling Works. The ESCP is supported by the Stage Specific Erosion and Sediment Control Plans (SSESCPs) that detail the control measures to be implemented for specific phases of the Enabling Works, including decanting earth bunds (DEBs), sediment retention ponds (SEPs) and containerised sediment control devices.
Specific designs of the flocculation systems will be included in Stage Specific Erosion and Sediment Control Plans (SSESCPs).
1.4.1. Settlement tanks
Condition 168 of the A2N consent requires that settlement tanks are utilised to control runoff from the grout plant and segment storage yard. These activities do not fall within the scope of this Enabling Works ESCP.
Condition 168 of the A2N consent also requires that two settlement tanks are installed in all ACZ, with the sizing of the tanks to be based on 2% of the contributing catchment. It is considered that the control measures, specifically DEBs, SRPs and containerised sediment control devices as detailed in the SSESCPs, achieve the outcomes sought by condition 168 and the requirement for settlement tanks can be appropriately modified as provided for by condition 169 of the A2N consent.
1.5 FTMP audience
The primary audience of this FTMP is the management staff of the project, including Environmental Advisors and Site Engineers.
This FTMP also provides details of the flocculation management practices to be utilised on the project to stakeholders including Auckland Council and the general community.
The details of the measures required for specific stages are set out in the SSESCPs. It is these documents that provide the on-site staff with the information needed to ensure that the approved flocculation management practices are implemented on site.
This separation of information and tailoring the included information to the intended audience is critical to ensuring that the flocculation management practices are correctly designed, understood, implemented, maintained and improved.
1.6 Relevant conditions
Table 1.1 identifies the resource consent conditions relevant to this FTMP and where they are addressed in the document.
Table 1-1: FTMP conditions and location in Plan
Condition No. Condition
Land Use Consent R/LUC/2016/1890
Flocculent Treatment Management Plan
59 At least 20 working days prior to the commencement of construction, the Consent Holder shall submit to Council (Team Leader Central Monitoring) for certification an FTMP which confirms the measures that will be taken to ensure that the construction of the Project or Project Stage will be generally consistent with the Water Quality Assessment and the Industrial and Trade Activities Assessment prepared by Golder Associates (NZ) Limited, both dated December 2014.
60 The Consent Holder shall request the Council's (Team Leader Central Monitoring) written determination as to whether the FTMP can be certified, in writing, within 10 working days of receipt of the FTMP.
No construction activity shall commence until certification from Council is provided.
61 The FTMP shall include, but not be limited to, the following matters: • Specific design details of the flocculent treatment system based on a batch dosing methodology for the site's settlement tanks, including the potential for use of non - flocculants (e.g. chitin based flocculants); • Monitoring, maintenance (including post-storm) and contingency programme (including a record sheet); • Details of optimum dosage (including assumptions); • Results of initial flocculent treatment trial; • A spill contingency plan; and • Details of the person or bodies who will hold responsibility for the long-term operation and maintenance of the flocculent treatment system and the organisational structure which will support this system.
62 Any change to an FTMP shall be submitted to the Council (Team Leader Central Monitoring) for certification.
63 The Consent Holder shall request the Council's (Team Leader Central Monitoring) written determination as to whether the proposed change can be certified, to be provided within 10 working days of submission of the change. No activity reliant upon a change to the FTMP can be undertaken until the change has been certified.
64 The Consent Holder shall comply with the ESCP for the duration of the earthworks associated with the Project. Relevant section of DWP
Section 1.2
Section 1.2
Section 1.4
Section 3.0 Section 4.0 Section 5.0 Section 6.0
Section 7.0
Section 1.8
Section 1.8
Section 1.4
As Built Certification
65 Prior to the commencement of bulk earthworks, a certificate signed by a Senior Qualified Person shall be submitted to the Council (Team Leader Central Monitoring) to certify that the erosion and sediment controls (including diversion bunds, silt fences and sumps) have been constructed in accordance with the certified ESCP(s) as required by Condition 53 of this consent. Section 1.3
Section 8.1
66 The certification from the Senior Qualified Person for these measures shall be supplied to the Council (Team Leader Central Monitoring) immediately upon completion of construction of those measures. Information supplied, if applicable, shall include: • The contributing catchment area; • The shape of structure (dimensions of structure); • The position of inlets/outlets; and • The stabilisation of the structure. Section 1.3
Section 8.1
General Performance Standards
68 The operational effectiveness and efficiency of all erosion and sediment control measures specifically required as a condition of resource consent, including the certified ESCP referred to in Condition 53, shall be maintained throughout the duration of earthworks, or until the Project site is permanently stabilised against erosion. Section 8.0
Section 9.0
70 The Consent Holder shall ensure that the erosion and sediment control measures are constructed and maintained in accordance with TP90, except where a higher standard is detailed in an ESCP/FTMP, in which case the higher standard shall apply. Section 8.0 Section 9.0
Specific conditions –discharge permit (contaminated land) R/REG/2016/1895 and land use consent R/LUC/2016/1890 (Contaminated Land and Resource Management (National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health) Regulations 2011)
Contaminated Soils Management Plan
139 The Consent Holder shall manage all soil disturbance works to minimise any discharge of debris, soil, silt, sediment or sediment-laden water from the subject site to either land, stormwater systems or the receiving marine environment. The implementation of erosion and sediment controls shall be in accordance with the ESCP required by Condition 53. Advice Note: Measures such as covering the excavations overnight and during heavy rainfall, diverting overland flow around the works area, and appropriate treatment of any water collected in an excavation prior to the disposal may be required to comply with this condition. Section 1.3 Section 8.0 Section 9.0
144 The Consent Holder shall implement the procedures for the management, treatment, temporary containment, testing, and disposal of groundwater and surface run-off water via the stormwater system in accordance with the report titled Auckland City Rail Link: Resource Consent Package 2: Aotea Station to North Auckland Line Construction and CRL Operation: Draft Erosion & Sediment Control Management Plan, dated 13 May 2016, prepared by Aurecon New Zealand Limited, and provided with the application. Section 1.3
Section 8.0
Section 9.0
Specific conditions –discharge permit (other) R/REG/2016/1896 and discharge permit (ITA) R/REG/2016/1898 (CONSTRUCTION)
Structural Controls
166 The Industrial Trade and Activity area for each of the Construction Support Areas shall not exceed the following:
CSA Exposed Area not to exceed (m 2 )
1 25,000
2 9,000
3 9,000
4 36,000
5 6,500
167 In the event that any CSA requires an increase in area, the following information shall be provided to the Team Leader –Central Monitoring whose certification shall be requested prior to implementation:
a. Plans and drawings outlining the details of the modifications; and
b. Supporting information that confirms how the proposal does not affect the capacity or performance of the existing structural and procedural controls.
168 The Consent Holder shall ensure that the following structural controls are constructed for the following catchment areas and design standards and they are completed prior to discharges commencing from the site:
Works / Controls Device catchment area
2 x Settlement Tanks located on CSA 4
Inlet protection measures Activity area of grout plant (400m 2 ), and segment storage yard (2660m 2 ) on
CSA 4 On all catch pits within CSA areas
2 x Settlement Tanks located in CSA 1, CSA 2, CSA 3, CSA 4 and CSA 5 All Active Construction Zone (ACZ) Design requirements
Settlement Tanks sizing to be based on 2% of the contributing catchment Design in accordance with Auckland Council Best Management Practice: Catch pit Protection Area (AC 2011). Settlement Tank sizing to be based on 2% of the contributing catchment
Bunding of Environmentally Hazardous Substances As required 110% largest container
169 In the event that any minor modifications to the structural system are required, the following information shall be provided to the Team Leader –Central Monitoring whose certification shall be requested prior to implementation: a. Plans and drawings outlining the details of the modifications; and Section 2.0
Section 1.8
Section 1.4.1
Section 1.4.1
Section 1.8
170
171 b. Supporting information that confirms how the proposal does not affect the capacity or performance of the existing structural and procedural controls.
Within 30 days of implementation, As-Built certification and plans of the stormwater management works, certified (signed) by a suitably qualified registered surveyor or a Chartered Professional Engineer as a true record of the stormwater management system, shall be provided to the Team Leader –Central Monitoring.
The As-Built plans shall include, but not be limited to: a. The surveyed location (to the nearest 0.1m) of the discharge points, with co-ordinates expressed in terms of NZTM and LINZ datum; b. Location, dimensions and levels of any major overland flow paths including cross sections and long sections;
c. Plans and cross sections of all stormwater management devices, including confirmation of the Water Quality Volume, storage volumes and levels of any outflow control structure d. Documentation of any discrepancies between the design plans and the As-Built plans.
Discharge Monitoring
173 Within 30 days of the installation of the water treatment systems, and prior to operation, the Consent Holder shall develop and submit to the Council (Team Leader Central Monitoring) for certification a discharge monitoring programme.
174
Page 11 | The water quality monitoring programme shall include, but not be limited to: a. Sampling locations (to include the final discharge from the treatment system located in CSA 1, CSA 2, CSA 3, CSA 5 and CSA 4);
b. Methods and procedures for discharge sampling; and
c. Monitoring parameters for analysis, which shall include:
Daily • • •
Water clarity (black disc) cm Turbidity (NTU) pH
Weekly (in addition to the above) • Total Suspended Solids g/m 3 • Total recoverable copper g/m 3 • Dissolved copper g/m 3 • Total recoverable zinc g/m 3 • Dissolved zinc g/m 3 • Total petroleum hydrocarbons g/m 3 • Ammoniacal nitrogen* g/m 3 • Nitrate nitrogen* g/m 3
*only in discharge from treatment systems in CSA 3 and CSA 4
d. identified trigger levels for each of the above parameters. These trigger levels shall be developed with reference to the ANZECC Guidelines for water quality where applicable; and
Section 8.1
Section 8.1
Section 9.0
Section 9.0
e. the methods and procedures for investigating and reporting stormwater discharge monitoring results to the Council (Team Leader Central Monitoring).
175 The discharge monitoring programme shall be implemented upon completion of works set out in Condition 168.
176 Within five working days of receipt of sample results showing contaminants exceeding the agreed trigger levels in Condition 174(d):
a. An investigation shall be undertaken to determine why exceedances were detected and to identify any additional source controls or treatment required; and b. The results of the investigation shall be reported to the Council (Team Leader Central Monitoring).
Discharge Reporting Requirements
177 Within eight weeks following the start of the monitoring required by Condition 173 a monitoring report shall be submitted to the Council (Team Leader Central Monitoring). The monitoring report shall include, but not be limited to, the following: a. a summary of the monitoring results to date; b. an interpretation of those results and suggestions for improvement to the site operations;
c. a programme for ongoing monitoring including the reporting of results; and d. a programme for the ongoing maintenance of the discharge water management and treatment system.
178
179 For the duration of the construction stages of the Project, the Consent Holder shall forward a report annually from the date of granting of this consent to the Council (Team Leader Central Monitoring) evaluating the site’s environmental performance for the year to date.
The Annual Report required by Condition 178 shall include but not be limited to:
a. all aspects of the performance of the EMP relating to this consent; b. a summary of all revisions and revised sections of the EMP; c. details of all inspections and maintenance of the stormwater system for the preceding 12 months;
d. details of and changes to the person(s) or body responsible for the maintenance of site and the organisational structure supporting this process; e. results and analysis of the preceding 12 months of stormwater monitoring, along with an interpretation of those results and suggestions for improvement to the site operations; and
f. records of any spills or incidents which occurred within the previous 12 months and the response which was undertaken.
Section 1.2 Section 9.0
Section 9.5
Section 9.5.2
Section 9.5.1
Section 9.5.1
Section 9.5.3
1.7 Sustainability
The Link Alliance is seeking an Infrastructure Sustainability Council of Australia (ISCA) Infrastructure Sustainability (IS) Rating. Further details can be found in the Project CEMP and Sustainability Rating Management Plan. Project sustainability requirements that relate directly to this FTMP are included in Appendix A. These requirements are imbedded within this ESCP to ensure that sustainability is a key focus and ‘the way we do things’.
In some cases, the IS requirements and sustainability goals enhance the designation and consent requirements.
1.8 FTMP review and updates
This FTMP is a live document that will be reviewed at least annually, or as a result of a material change to the Project, or to address unforeseen erosion and sediment runoff effects arising from construction, or unresolved complaints. The ability to make changes to the FTMP is vital to maintain its effectiveness and relevance. Modification may also be required to accommodate additional consents as detailed design and construction methods are finalised.
Revisions to the FTMP will be made:
As the Link Alliance considers necessary Promptly on any material change (including named personnel changes) If requested by Auckland Council As and when reasonably required by the City Rail Link Limited.
Any material changes to this FTMP must be certified by Auckland Council prior to any on-site activity reliant upon the change commencing (as per conditions 62 and 63 of the A2N resource consent). Refer to the CEMP for further detail on the review and updating process.
