Tonkin & Taylor Ltd | 105 Carlton Gore Rd, Newmarket, Auckland 1023, New Zealand PO Box 5271, Wellesley St, Auckland 1141 P +64-9-355 6000 F +64-9-307 0265 E akl@tonkintaylor.co.nz Job No: 1004393.2000 8 May 2019 Auckland Transport c/- Tattico Limited PO Box 91562 Victoria Street Auckland 1142 Attention: Mark Vinall Dear Mark Downtown Public Space Ground Contamination Assessment 1 Introduction The Downtown Framework 2014 identified a long-term plan to transform the central wharves and downtown public realm through the creation of enhanced public space in the area between Princess Wharf and the Downtown Ferry Terminal (Pier 2). This area is referred to as the Downtown Public Space (DPS) and is part of the wider Downtown Waterfront programme of works being delivered for the 36 th Americas Cup (AC36) to be held in Auckland in 2020/21. The Downtown Programme is a result of a collaboration between Auckland Transport (AT), Auckland Council (AC) and Panuku Development Auckland. The Programme includes a number of projects as part of overall improvements to the city centre. In addition to the Downtown Public Space, the Programme includes the upgrade of the Quay Street Seawall, proposed Downtown Ferry Redevelopment, a proposed mooring dolphin at the end of Queens Wharf, and proposed streetscape works and bus facilities in Quay Street. AT, on behalf of AC, has commissioned Tonkin + Taylor Ltd (T+T) to provide specialist inputs to support the resource consent application for the DPS project. This report provides an assessment of the ground contamination effects and consent requirements. 2 Proposed works 2.1 Downtown Public Space Isthmus Design Group Ltd completed a concept design for the DPS 1 incorporating a tidal shelf of interconnected spaces, a Pōhutukawa coastal forest connecting the tidal shelf to Quay Street, tidal pools and outcrops as presented in Figure 2-1. Selected design drawings are provided for reference in Appendix A. 1 Downtown Public Space. Resource Consent Package. Prepared for Auckland Council by Isthmus Design Group Ltd, dated 3 May 2019.
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Tonkin & Taylor Ltd | 105 Carlton Gore Rd, Newmarket, Auckland 1023, New ZealandPO Box 5271, Wellesley St, Auckland 1141 P +64-9-355 6000 F +64-9-307 0265 E [email protected]
Downtown Public SpaceGround Contamination Assessment
1 Introduction
The Downtown Framework 2014 identified a long-term plan to transform the central wharves anddowntown public realm through the creation of enhanced public space in the area between PrincessWharf and the Downtown Ferry Terminal (Pier 2). This area is referred to as the Downtown PublicSpace (DPS) and is part of the wider Downtown Waterfront programme of works being delivered forthe 36th Americas Cup (AC36) to be held in Auckland in 2020/21.
The Downtown Programme is a result of a collaboration between Auckland Transport (AT), AucklandCouncil (AC) and Panuku Development Auckland. The Programme includes a number of projects aspart of overall improvements to the city centre. In addition to the Downtown Public Space, theProgramme includes the upgrade of the Quay Street Seawall, proposed Downtown FerryRedevelopment, a proposed mooring dolphin at the end of Queens Wharf, and proposedstreetscape works and bus facilities in Quay Street.
AT, on behalf of AC, has commissioned Tonkin + Taylor Ltd (T+T) to provide specialist inputs tosupport the resource consent application for the DPS project. This report provides an assessment ofthe ground contamination effects and consent requirements.
2 Proposed works
2.1 Downtown Public Space
Isthmus Design Group Ltd completed a concept design for the DPS1 incorporating a tidal shelf ofinterconnected spaces, a Pōhutukawa coastal forest connecting the tidal shelf to Quay Street, tidalpools and outcrops as presented in Figure 2-1. Selected design drawings are provided for referencein Appendix A.
1 Downtown Public Space. Resource Consent Package. Prepared for Auckland Council by Isthmus Design Group Ltd, dated 3May 2019.
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Tonkin & Taylor LtdDowntown Public SpaceGround Contamination AssessmentAuckland Transport
8 May 2019Job No: 1004393.2000
The project is staged (Stage 1 and Stage 2) as indicated in Figure 2-1 below. This report refers toeffects arising from Stage 1 only. Stage 1 covers a length of approximately 100 m of the existingwaterfront and extends approximately 40 m in to the Ferry Basin at its greatest extent. There is noproposed change to the MHWS location within this works.
The resource consent application for the DPS is being prepared on the assumption that all existingferry berths on Piers 3 and 4 are relocated to the western edge of Queens Wharf and the upgrade ofthe seawall is complete. Separate resource consent applications have been made for the demolitionand relocation of Piers 3 and 4 and to Queens Wharf West and the upgrade of the seawall.
Figure 2-1 Project boundary of the Downtown Public Space and proposed staging (Source: Isthmus DesignGroup Ltd, 2019)
2.2 Construction
Construction methodologies have been assessed and are presented in the DIDP JV (Downer, HEB,Soletanche Bachy) draft construction management plan2.
The following preliminary construction methodology is anticipated for the works. This will be furtherrefined as more detailed design work is completed and the construction contractors provide furtherinput.
· Demolish existing structures:- Saw cut deck into sections and remove;- Extract or cut off piles and remove, or cut-off and reuse where appropriate; and- Remove pavements and associated structures (fencing, bollards, seating etc.).
· Install new piles. The key elements of the methodology, as related to contamination effects,are:- A number of piling options are being considered including working from barges, a
temporary jetty/staging platform or from land. The landside options may require theconstruction of a temporary works platform, possibly including installation of sometemporary piles, depending on progress of seawall strengthening measures; and
- Pile casings will be driven, open ended, to refusal using the drilling, vibro hammering orjetting techniques. In all cases once the pile casing is set and design embedment is
2 Draft Construction Management Plan, Downtown Public Space. Prepared for Auckland Transport by DIDP JV (Downer,HEB, Soletanche Bachy), dated 21 March 2019. Reference DN1158.
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Tonkin & Taylor LtdDowntown Public SpaceGround Contamination AssessmentAuckland Transport
8 May 2019Job No: 1004393.2000
achieved, the marine sediments will be cleaned out of the casing and a socket advancedinto the underlying rock. Once the pile has been drilled prefabricated reinforcing steelcages will be lifted into place and lowered into the casing, concreting will then takeplace.
· Construct decks / tree pits (combination of precast and in situ concrete).· Install new service connections (shallow drainage, power, water etc.) to Quay Street as
necessary.· Finishing works (surfacing, balustrades etc.).
3 Assessment of effects
T+T has recently prepared ground contamination assessments for the Quay Street seawall seismicstrengthening and utilities relocations projects, comprising Detailed Site Investigations (DSI)3 andSite Management Plans (SMP)4. These assessments also investigated the condition of marinesediments within the Ferry Basin, in the vicinity DPS project.
In summary testing of marine sediments identified that these contain:
· Trace concentrations (<0.001 % w/w) of asbestos fibres and fines. These results likely reflectthe entrainment of asbestos fibres and fines in stormwater which discharges into the harbourfrom the many asbestos clad roofs in the catchment.
· Elevated concentrations (above published background/cleanfill levels) of one or more metalswere measured in the majority of samples tested. However, all samples reported metalconcentrations that comply with the acceptance criteria for the protection of both humanhealth and environmental receptors.
· One or more PAH compounds were detected above the laboratory limits of reporting in themajority of samples tested. Heavy end (C15+) TPH compounds were also reported in themajority of samples tested for these compounds. These results suggest that marine sedimentshave generally been impacted by low concentrations of heavy end hydrocarbons. However, allsamples reported PAH and TPH concentrations that comply with the acceptance criteria forthe protection of both human health and environmental receptors.
Overall, the available data indicates that the only health effects associated with the marinesediments relate to handling and disposal of the excavated spoil and dredgings, which only requiressimple controls, effectively standard earthworks controls supplemented with basic PPE, as follows:
1 Where the potential for direct contact (including accidental contact) with sediments exists,e.g. during manual handling/excavation activities, then full-length clothing and impermeablegloves shall be worn (as a minimum);
2 Decontamination facilities should be provided so that personnel can dress down frompotentially contaminated PPE (clothing/gloves) in a controlled manner and ensure that a highlevel of personal hygiene can be maintained (washing of hands and face after dressing down,prior to eating etc.);
3 Handling of spoil should be undertaken in a manner that avoids:
3 Quay Street Seawall Upgrade, Ground Contamination Assessment. Report prepared for Auckland Transport by Tonkin &Taylor Ltd, dated May 2018. Reference no. 1004393.v4; andQuay Street End to End Utilities Relocation Project, Ground Contamination Assessment. Report prepared for AucklandTransport by Tonkin & Taylor Ltd, dated December 2018. Reference no. 1004393.3000.v6.4 Quay Street Seawall Upgrade, Site Management Plan for Ground Contamination. Report prepared for Auckland Transportby Tonkin & Taylor Ltd, dated June 2018. Reference no. 1004393.0000.v4; andQuay Street End to End Utilities Relocation Project, Site Management Plan for Ground Contamination. Report prepared forAuckland Transport by Tonkin & Taylor Ltd, dated December 2018. Reference no. 1004393.3000.v5.
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Tonkin & Taylor LtdDowntown Public SpaceGround Contamination AssessmentAuckland Transport
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a Discharges of the sediment to ground or the marine environment;b Generation of dusts;c Runoff of surface water or rainfall which has come into contact with sediment;
4 Offsite disposal of spoil should occur to a facility that is authorised to accept the level ofcontamination, noting that the sediments have been shown to include low concentrations ofasbestos.
5 In accordance with the requirements of the Asbestos in Soils Guidelines (refer to Section 4)equipment which has come into contact with asbestos containing sediments will need to bedecontaminated and inspected by a Contaminated Land Specialist or Competent Personbefore being removed from the work area.
6 Contingency and mitigation measures should be developed to address potentialcontamination related incidents including: unexpected contamination conditions (includinghigher concentrations of asbestos); if accidental discharges occur; complaints are received inrelation to the works. These measures should include seeking advice from a ContaminatedLand Specialist where necessary.
Implementation of these controls (as a minimum) will appropriately manage health effects such thatthey are less than minor an acceptable. These requirements can be incorporated into theConstruction Environmental Management Plan (CEMP) which is expected to be developed for theworks.
The environmental effects of ground contamination present in the CMA relate primarily todischarges of contaminated sediment during piling works that disturb the seabed. T+T’s ecologicalassessment5 concludes that the construction and piling activities will potentially result in localisedsediment generation. However, the potential for sediment discharges will be controlled by standardconstruction measures and as a result short term effects are considered to be minor. Therefore, aslong as spoil generated by the piling works is also managed in accordance with the controlsdescribed above, ground contamination related effects on the environment are expected to be lessthan minor. These requirements can be incorporated into the CEMP which is expected to bedeveloped for the works.
If excavation is required landside to either construct a temporary works platform or for serviceconnections (refer to Section 2), the scale and duration of these works are expected to be minor innature (few tens of m3 and days in duration). Implementation of controls described above duringany minor excavation works will appropriately manage potential health and environmental effectssuch that they are less than minor.
4 Assessment of consenting requirements
The rules and associated assessment criteria relating to the control of contaminated sites in theAuckland region are specified in the following documents:
· Resource Management (National Environmental Standard for Assessing and ManagingContaminants in Soil to Protect Human Health) Regulations 2011 (NES Soil);
· Auckland Unitary Plan (AUP); and· Health and Safety at Work (Asbestos) Regulation (2016).
5 Downtown Public Space - Stage 1, Marine Ecological Assessment. Prepared for Auckland Council by Tonkin & Taylor Ltd,dated April 2019. Reference no. 1004393.2000.v5
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Tonkin & Taylor LtdDowntown Public SpaceGround Contamination AssessmentAuckland Transport
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The NES Soil considers issues relating to land use and the protection of human health while the AUPhas regard to issues relating to the protection of the general environment, including ecologicalreceptors.
The management of asbestos in soils is regulated under the Asbestos Regulations. In order to helpachieve compliance with the Asbestos Regulations, WorkSafe New Zealand has prepared anApproved Code of Practice (ACoP): Management and Removal of Asbestos (September 2016). TheACoP refers readers to the “New Zealand Guidelines for Assessing and Managing Asbestos in Soil”(herein referred to as the Asbestos in Soils Guidelines) which were published in November 2017 byBRANZ Ltd.
We note the following with respect to the application of the above consenting framework to thisproject, which is principally limited to works within the CMA:
· The NES Soil and the associated user’s guide6 do not provide any advice on its application inthe CMA. However, the land uses/activities it considers and its application to “soilcontamination” all imply that it was not intended to apply to the CMA;
· The low concentrations of asbestos present in the marine sediments can be managed as“unlicensed work” within the framework set out in the Asbestos in Soil Guidelines andtherefore do not create any consequential consenting triggers under the NES Soil;
· Uses of the CMA and discharges of contaminants to it are controlled by the more restrictivesections 12 and 15 of the RMA. The contaminated land rules included in the AUP relate tomanaging the effects of “land containing elevated levels of contamination” and the rulesvariously describe “land”, “ground”, “groundwater” and “surface water” (the later in thecontext of within or discharging from a site). The CMA is also addressed specifically in othersections of the plan, including Chapter F. For these reasons we interpret that thecontaminated land rules of the AUP were not intended to apply directly to the CMA. Potentialcontamination related effects on the environment and proposed controls can addressed bythe other consents required under the AUP for works in the CMA; and
· As noted in the preceding sections, if excavation is required to either construct a temporaryworks platform or for service connections, the scale and duration of these works expected tobe minor in nature and fall well within the permitted activity thresholds of the AUP (200 m3)and NES Soil (>>200 m3 considering the area of the wider reclamation).
For these reasons we consider that:
· It was not intended that the NES Soil would apply for works in the CMA and any landsideexcavation works required temporary works platform or service connections are expected tofall within permitted activity thresholds. We therefore conclude that consent should not berequired under the provisions of the NES Soil for Stage 1 of the proposed DPS project;
· The potential environmental effects and proposed controls can addressed by the otherconsents required under the AUP for works in the CMA and any landside excavation worksrequired temporary works platform or service connections are expected to fall withinpermitted activity thresholds. We therefore conclude that consent should not be requiredunder the ground contamination provisions of the AUP for Stage 1 of the proposed DPSproject; and
· The piling works should be managed in accordance with the “unlicensed work” framework setout in the Asbestos in Soil Guidelines. This does not require consent or approvals as long as
6 Ministry for the Environment. 2012. Users’ Guide: National Environmental Standard for Assessing and ManagingContaminants in Soil to Protect Human Health. Wellington: Ministry for the Environment.
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Tonkin & Taylor LtdDowntown Public SpaceGround Contamination AssessmentAuckland Transport
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the works are appropriately managed, which should be able to be achieved by applying thecontrols recommended in Section 3.
5 Applicability
This report has been prepared for the exclusive use of our client Auckland Transport, with respect tothe particular brief given to us and it may not be relied upon in other contexts or for any otherpurpose, or by any person other than our client, without our prior written agreement.
Recommendations and opinions in this report are based on discrete sampling data. The nature andcontinuity of contamination away from the sampling points are inferred and it must be appreciatedthat actual conditions could vary from the assumed model.
Tonkin & Taylor Ltd
Environmental and Engineering Consultants
Report prepared by: Authorised for Tonkin & Taylor Ltd by:
COPYRIGHT ON THIS DRAWING IS RESERVED DO NOT SCALE FROM THIS DRAWING - IF IN DOUBT, ASK.
THIS DRAWING IS NOT TO BE USEDFOR CONSTRUCTION PURPOSESUNLESS SIGNED AS APPROVED
SCALE (A3)
DRAWING STATUS
REVDWG No.APPROVED
TITLE
PROJECT
CLIENT
REV DATE
AUCKLAND TRANSPORT
DIDP - DOWNTOWN PUBLIC SPACE
QUAY STREET, AUCKLAND CBD
EXISTING GENERAL ARRANGEMENT
1:500 1004393.2000-DPS-CIV-001 1
MGM Feb.19MIGU Feb.19 DEVELOPED DESIGN
1 DEVELOPED DESIGN ANRI
NOT FOR CONSTRUCTION
ANRI Feb.19
MIGU
ORIGINAL IN COLOUR
A3 SCALE 1:5000 5 10 15 20 25 (m)
NOTES:1. ALL DIMENSIONS ARE IN MILLIMETRES UNLESS NOTED OTHERWISE.2. COORDINATE DATUM: NZ GEODETIC DATUM 2000, MT EDEN CIRCUIT.3. LEVEL DATUM: AUCKLAND VERTICAL DATUM 1946 (MSL) CD = -1.743m AVD-46.4. AERIAL PHOTO SOURCED FROM AUCKLAND COUNCIL GIS WEBSITE.5. BASE SURVEY IS FROM BECA, DWG REF. 3125394-WS-001 PROVIDED ON 11/12/2017.6. SERVICE LOCATIONS ARE INDICATIVE ONLY. CONTRACTOR IS RESPONSIBLE FOR
LOCATING AND PROTECTING ALL SERVICES ONSITE PRIOR TO UNDERTAKING ANYWORKS.
7. END TO END UTILITIES TRENCH LOCATION AND DETAILS BY ENVIVO ON 06/12/2018.8. DRAWINGS DOES NOT INCLUDE ADDITIONAL SERVICES PICKED UP THROUGH
RECENT JFC INVESTIGATIONS.
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500mm PROPOSED MAIN SERVICE SPINE REFER TODWG. 1004393-DPS-CIV-001 & 002 FOR DETAIL (FOR