New Intercity Fleet Maintenance Facility …...Dewatering to install the track subsurface drainage is expected to have a minor, short term impact onthelocalwatertable levelduring construction,

New In erci y Flee Main enance Facili y

Groundwa er and Dewa ering Managemen Plan

Groundwater and Dewatering Management Plan for EPBC 2016_7681

Prepared for: Project Team Reference No: Revision H

31/05/2018

www.smec.com

http:www.smec.com

- - -

Docume t/Report Co trol Form

File Name: NIF SME RPT GE360001

Proje t Name: Inter ity Fleet Maintenan e Fa ility

Proje t Number: 30012174

Revision Number: H

Documen /Repor Con rol Form

Report for Groundwater and Dewatering Management Plan for EPBC 2016_7681 | New Intercity Fleet Maintenance

Facility Groundwater and Dewatering Management Plan | Project Team | Revision H SMEC Aus ralia

Revisio History

Revisio # Date Prepared by Reviewed by Approved for Issue by

A 25-01-2018

B 7-02-2018

C 20-02-2018

D 21-03-2018

E 23-03-2018

F 11-05-2018

G 14-05-2018

H 31-05-2018

Issue Register

Distributio List Date Issued Number of Copies

John Holland; 31-05-2018 1

SMEC Proje t File: 30012174

The information within this do ument is and shall remain the property of:

SMEC Australia Pty Limited

Dis laimer

This report is onfidential and is provided solely for the purposes of des ribing the proje t Groundwater and Dewatering Management Plan. This report is provided pursuant to a Consultan y Agreement between SMEC Australia Pty Limited (“SMEC”) and John Holland under whi h SMEC undertook to perform a spe ifi and limited task for John Holland. This report is stri tly limited to the matters stated in it and subje t to the various assumptions, qualifi ations and limitations in it and does not apply by impli ation to other matters. SMEC makes no representation that the s ope, assumptions, qualifi ations and ex lusions set out in this report will be suitable or suffi ient for other purposes nor that the ontent of the report overs all matters whi h you may regard asmaterial for your purposes.

This report must beread as awhole. The exe utive summary is not a substitute for this. Any subsequent report must be read in onjun tion with this report.

The report supersedes all previous draft or interim reports, whether written or presented orally, before the date of this report. This report has not and will not be updated for events or transa tions o urring after the date of the report or any other matters whi h might have a material effe t on its ontents or whi h ome to light after the date of the report. SMEC is not obliged to inform you of any su h event, transa tion or matter nor to update the report for anything that o urs, or of whi h SMEC be omes aware, after thedate of this report.

Unless expressly agreed otherwise in writing, SMEC does not a ept a duty of are or any other legal responsibility whatsoever in relation to this report, or any related enquiries, advi e or other work, nor does SMEC make any representation in onne tion with this report, to any person other than John Holland. Any other person who re eives a draft or a opy of this report (or any part of it) or dis usses it (or any part of it) or any related matter with SMEC, does so on the basis that he or she a knowledges and a epts that he or she may not rely on this report nor on anyrelated information or advi e given by SMEC for any purpose whatsoever.



Table of Con en s

Glossary of Terms, Acro yms..............................................................................................i

Executive Summary ............................................................................................................iii

1 I troductio .................................................................................................................... 6

1.1 Ba kground........................................................................................................ 6 1.2 Proje t Des ription ............................................................................................. 6 1.3 Purpose of Plan.................................................................................................. 7 1.4 Risk to Groundwater........................................................................................... 8

1.4.1 Constru tion Phase..................................................................................... 8 1.4.2 Operational Phase ...................................................................................... 9 1.4.3 Risk Assessment ...................................................................................... 10

2 Regulatory Co text...................................................................................................... 14

2.1 Conditions of Approval ..................................................................................... 14

2.1.1 Conditions Atta hed to the Approval: ........................................................ 14 2.1.2 Li ensing ................................................................................................... 18

3 Hydrogeological Setti g.............................................................................................. 20

3.1 Hydrogeology ................................................................................................... 20

3.1.1 Aquifers .................................................................................................... 20 3.1.2 Re harge and Dis harge........................................................................... 20 3.1.3 Gradient andFlow Dire tion ...................................................................... 20 3.1.4 Depth to Water.......................................................................................... 20 3.1.5 Groundwater Quality ................................................................................. 21 3.1.6 Groundwater Dependent E osystems....................................................... 21 3.1.7 Benefi ial Use........................................................................................... 21

4 Grou dwater Depe de t Ecosystems ........................................................................ 23

4.1 Summary.......................................................................................................... 23 4.2 Monitoring for Groundwater Dependent E osystems........................................ 23

5 Mo itori g Program..................................................................................................... 26

5.1 Introdu tion ...................................................................................................... 26 5.2 Pre-Constru tion Monitoring ............................................................................. 26

5.2.1 Con ept Design Stage .............................................................................. 26 5.2.2 Pre-Constru tion Detailed Design Stage ................................................... 26

5.3 Long Term Monitoring Lo ations ...................................................................... 26 5.4 Monitoring Frequen y & Reporting Requirements ............................................ 27

5.4.1 Justifi ation of Frequen y.......................................................................... 29 5.4.2 Reporting Requirements ........................................................................... 29

6 Sampli g Regime a d Parameters ............................................................................. 30

6.1 Introdu tion ...................................................................................................... 30 6.2 Regime and Parameters................................................................................... 30

6.2.1 Standards ................................................................................................. 30 6.2.2 Water Level Measurement ........................................................................ 30 6.2.3 Sample Colle tion Methodology & Analysis .............................................. 30



6.3 Sample Quality Control Regime ....................................................................... 32

6.3.1 Identifi ation and Re ords......................................................................... 32 6.3.2 Sample Colle tion ..................................................................................... 33 6.3.3 Sample Preservation and Transport.......................................................... 33 6.3.4 Chain of Custody ...................................................................................... 33 6.3.5 Laboratory Analysis................................................................................... 33 6.3.6 Quality Control Samples............................................................................ 33

7 Data A alysis a d Reporti g ...................................................................................... 34

7.1 Introdu tion ...................................................................................................... 34 7.2 Groundwater Quality ........................................................................................ 34

7.2.1 Trigger values ........................................................................................... 34 7.2.2 Trends .................................................................................................... 35

7.3 Groundwater Levels ......................................................................................... 36 7.4 GDE Management A tion Triggers ................................................................... 37

8 Co structio Dewateri g Ma ageme t...................................................................... 40

8.1 Introdu tion ...................................................................................................... 40 8.2 Dewatering ....................................................................................................... 40

8.2.1 Inflows .................................................................................................... 40 8.2.2 Pumping .................................................................................................... 41 8.2.3 Water Quality ............................................................................................ 41 8.2.4 Disposal .................................................................................................... 41

9 E viro me tal Ma ageme t ....................................................................................... 43

9.1 Environmental Management Obje tives and Key A tions................................. 43 9.2 Environmental Mitigation Measures and Remediation Measures...................... 48

9.2.1 Introdu tion ............................................................................................... 48 9.2.2 Mitigation Measures.................................................................................. 48 9.2.3 Triggering of Water level / Quality Mitigation Measures............................. 48 9.2.4 GDE Mitigation and Management Strategies............................................. 48 9.2.5 Remediation Measures ............................................................................. 49 9.2.6 GDE Contingen y Plan ............................................................................. 49

10 A further assessme t a d mo itori g of the health of the GDE by a ecologist would also be carried out i li e with the above suggested measures.Refere ces ................. 51

Table of Figures

Figure 1: Approach for grou dwater quality (a d co tami atio ) assessme t ............ 35

List of Tables

Table 1-1: Risk Framework ................................................................................................ 10 Table 1-2: Likelihood a d co seque ce........................................................................... 11 Table 1-3: Risk assessme t a d co trols ......................................................................... 11 Table 2-1: Departme t of the E viro me t a d E ergy (DoEE) Guideli e for “Grou dwater Ma ageme t Pla s .................................................................................... 15 Table 5-1: Grou dwater mo itori g bore details ............................................................. 26 Table 5-2: Mo itori g freque cy a d requireme ts......................................................... 28 Table 6-1: A alytical suite ................................................................................................. 32



Table 7-1: A alytes of co cer a d adopted trigger values............................................ 34 Table 7-2: Low Level Trigger Value................................................................................... 36 Table 7-3: Swamp Forest GDE Trigger a d Actio .......................................................... 38 Table 7-4: Melaleuca bico vexa GDE Trigger a d Actio ............................................... 39 Table 8-1: Estimated grou dwater i flows to excavatio s u der high water table co ditio s........................................................................................................................... 40 Table 8-2: Recharge water quality targets ........................................................................ 41 Table 9-1: Key eleme ts of e viro me tal ma ageme t to achieve ide tified objectives

43 Table 9-2: Key actio s for ma ageme t of grou dwater................................................. 44

Appe dices

– Site Pla s

– Approval EPBC 2016_7681



Glossary of Terms, Acronyms

Acro ym Name

Australian and New Zealand Guidelines for Fresh and Marine Water ANZECC

Quality 2000

As Arseni

AHD Australian Height Datum

BACI Before-After Control-Impa t

Ca Cal ium

CBD Central Business Distri t

Cd Cadmium

Cl Chloride

COC Chain of Custody

CMP Constru tion Management Plan

Cu Copper

DO Dissolved Oxygen

DoEE Department of the Environment and Energy

DPI NSW Department of Industry Land and Water Division

EC Ele tri al Condu tivity

Environment Management Plan EMP -(C) Constru tion

-(O) Operation

EP&A A t Environ ental Planning and Assess ent Act 1979

EPA NSW Environment Prote tion Authority

EPBC A t Environ ent Protection and Biodiversity Conservation Act 1999

EPL Environment Prote tion Li en e

Fe Iron

FFMP Flora and Fauna Management Plan

GDE Groundwater Dependent E osystem

GWDMP Groundwater and Dewatering Management Plan

HCO3 Bi arbonate

Hg Mer ury

HV High Voltage

K Permeability, of soil, ro k et . or Potassium

Km Kilometre

L/se Litres per Se ond, measure of flow

LGA Lo al Government Area

M Meter

m/day meters per day, measure of flow rate or permeability

m/se meters per se ond, measure of flow rate or permeability

Mbgl Meters below ground level

Mg Magnesium

Mn Manganese

NSW New South Wales

Na Sodium

NATA National Asso iation of Testing Authorities

NH4 Ammonia

Ni Ni kle

NIF New Inter ity Fleet

NIFMF New Inter ity Fleet Maintenan e Fa ility

NWQMS National Water Quality Management Strategy

Pb Lead

REF Review of Environmental Fa tors

SIS Spe ies Impa t Statement

SO4 Sulphate

SWL Standing Water Level

TARP Trigger A tion Response Plan

Report for New Intercity Fleet Maintenance Facility Groundwater and Dewatering Management Plan | Groundwater and

Dewatering Management Plan for EPBC 2016_7681 | Project Team | Revision H SMEC Aus ralia | Page i

Acro ym Name

TDS Total Dissolved Solids

TSC A t Threatened Spe ies Conservation A t 1994

TfNSW Transport for New South Wales

TOC Top of Casing

Zn Zin


Facility Groundwater and Dewatering Management Plan | Project Team | Revision HSMEC Aus ralia

Execu ive Summary

The NSW Government is delivering a New Inter ity Fleet to repla e the trains arrying ustomers from Sydney to the Central Coast, New astle, the Blue Mountains and the Illawarra. A purpose-built maintenan e fa ility is being onstru ted at Kangy Angy onthe Central Coast to servi e and maintain the new fleet of trains. To support the Proje t determination, approval was sought and re eived under Se tion 130(1) and 133 of the Environ ent Protection and Biodiversity Conservation Act 1999 (EPBC A t). The New Inter ity Fleet Maintenan e Fa ility, Kangy Angy, NSW (EPBC 2016/7681) approval (Appendix B) requires a Groundwater Management Plan to be prepared and implemented for the Proje t (EPBC Condition No. 2).

The onditions atta hed to the proje t approval are dis ussed within this report and in lude:

• (Co onwealth) “A detailed Groundwater Assess ent is to be developed as part of, but prior to the finalisation of the detailed design process undertaken to confir the potential i pacts of the Project on local and regional groundwater conditions. The groundwater assess ent shall identify anage ent and itigation easures to be i ple ented to ensure that groundwater i pacts are appropriately anaged”;

• (State) Groundwater and Dewatering Manage ent Plan as described in section 7.10.4 of the review of environ ental factors; and

• (State) The Groundwater and Dewatering Manage ent Plan ust be sub itted to the Depart ent at least 1 onth before construction co ences, and construction cannot co ence until the plan is approved by the Minister.

The groundwater assessment shall be prepared in onsultation with WaterNSW, DPI and Central Coast Coun il, and in lude onsideration of impa ts to adja ent GDE’s.

The purpose of this plan is to:

1. Provide a referen e guide for the management of groundwater during onstru tion and operation of the fa ility;

2. To minimise potential impa ts to groundwater dependent e osystems (GDE’s) and other benefi ial uses i.e. nearby registered groundwater bores;

3. Comply with the Conditions of Approval listed in the New Inter ity Fleet Maintenan e Fa ility Proje t Determination Report (August 2017), in parti ular the requirements of the EPBC Approval Condition No.2; and

4. Comply with statutory or legislative requirements as they apply, i.e. Water Management A t 2000.

The site is underlain by quaternary alluvium and Terrigal Formation bedro k. These two geologi al units form two separate aquifer systems. Water quality information from registered bores indi ates groundwater is relatively fresh in the alluvial aquifer and generally fresh to slightly bra kish in the Terrigal Formation.

The potential risks related to groundwater in lude;

• Risk to the project due to groundwater (inflows, dewatering, construction i pacts); • Risk to groundwater due to the project (conta ination, reduced flow, changes in quality), the risk can be further divided based on the Construction Phase and the Operational Phase; and

• Risk to groundwater dependent ecosyste s due to project i pact on groundwater.

To aid in mitigation of potential risks and to manage impa ts on groundwater dependent e osystems, this do ument presents;

• An assess ent of the current groundwater regi e; • A su ary of potential i pacts related to the facility;



• A su ary itigation / re ediation easures; and • A onitoring progra (including groundwater and GDEs)

The primary strategies to manage key risks in lude:

• Baseline testing/sa pling prior to construction; • Continuous onitoring during construction and operation: and • Develop ent and i ple entation of flora & fauna/conservation anage ent plans (including contingency easures)

Mitigation measures whi h may be undertaken in the event impa ts are dete ted or ontamination found in lude:

• Reducing dewatering rates to allow water table recovery; • Recharge of pu ped water through:

o Soak away trenches; or

o Reinjection bores.

o Redirection of recharge to GDE areas should it is noted a decline in GDE health

• Mini ising earthworks during periods of rainfall; • Controlling surface water runoff and recharge; and • Physical re oval of any conta ination sources.

The proje t onstru tion is not anti ipated to ause permanent hanges to the groundwater level or quality. GDE areas are not anti ipated to be affe ted by onstru tion dewatering. Dewatering to install the tra k subsurfa e drainage is expe ted to have a minor, short term impa t on the lo al water table level during onstru tion, this impa t is anti ipated to be within the natural range of variation. Proje t onstru tion may ause ontamination of the aquifer through fuel, oil or hemi al spills however su h spills are onsidered unlikely and/or minor on the basis that the site fa ility/operations will not be storing large amounts of hemi als and appropriate ontrol measures will be initiated via the design phase and through the CEMP and OEMP.

In the event of ontamination remediation measures will in lude:

• Assess ent of the i pact through: o Deter ining and i ediately controlling the source and if able re oving it (for

exa ple excavation of conta inated soil);

o Increased onitoring and installation of additional onitoring bores to assess the distribution and concentration of any igrating conta ination;

o Assess the risk to the environ ent, beneficial use and potential for har ; and if required;

o Undertake nu erical flow and fate and transport odelling to assess potential ove ent, receiving environ ent and re ediation options;

• Develop ent of a re ediation action plan.

If the above assessment indi ates there is a potential risk of ontamination and harm to the environment (aquifer/surfa e water movement offsite), benefi ial use or GDE’s a remediation a tion plan will be developed whi h may in lude one or more of the following:

o Pu p and treat; o Cut off walls;

o Reactive barriers;

o Initiation of a bush regeneration progra (via the Vegetation Manage ent Plan) of the GDE co unities;

o A co bination of the above.



• Verify the re ediation easures through; increased onitoring and reassess ent of odelling.

Any remediation measures, if determined to be required, will be in onsultation with the EPA, DPI and TfNSW.

With regards to operations, the primary impa t to groundwater level would be due to the under tra k drainage system. In general:

• The tra k is being onstru ted primarily on fill embankments, water draining into the under tra k drainage will be surfa e water;

• Where the under tra k drainage system is required to fall below the design groundwater level, blank (i.e. non-slotted) pipe shall be used to prevent groundwater ingress; and

• Groundwater ingress to the under tra k drainage system may o ur during periods of high groundwater. At these times, the water re harge to the GDE would be high and flow through the drainage system would also be high, hen e the risk to GDE from lower water levels or ontamination would be minimal.

Whilst the risk to GDE’s would be minimal, where an impa t to the groundwater o urs (for example, signifi ant noti eable groundwater drawdown from the interse tion of the groundwater by the under tra k drainage system) ontingen y/mitigation measures may in lude:

• Re harge of groundwater between the affe ted GDE and sour e of the drawdown (using polished water from detention basins or pumped from the dewatering system).

• If hemi als of on ern are noted in the monitoring bores, in addition to determining and eliminating the sour e, then as an interim ontingen y measure the monitoring bores may also be used to draw the watertable down in the vi inity of the GDE to prevent hemi als migrating into the natural environment and to mitigate the risk of ontamination in the short term while longer term remedial measures an be implemented.

• Long term mitigation ould in lude measures su h as ut-off walls, pump and treat systems or hemi al/biologi al treatment.

A further assessment and monitoring of the health of the GDE by an e ologist would also be arried out in line with the above suggested measures.

Operational requirements will be further reassessed in the development of the OEMP using groundwater monitoring results obtained during baseline and onstru tion phase.



1 In roduc ion

1.1 Backgrou d

The NSW Long Term Transport Master Plan (NSW Government 2012, Transport Master Plan) identified the need to enhan e rail passenger servi es; in parti ular for longer distan e travel outside the metropolitan networks. In May 2014 the NSW Government announ ed its intention to invest in the pro urement of the New Inter ity Fleet (NIF), a fleet of trains that will over the Central Coast, New astle and South Coast lines. The new fleet will allow for the repla ement of the existing older train fleet urrently in use.

The primary need for the “New Inter ity Fleet Maintenan e Fa ility” (the Proje t) is a dire t result of the urrent pro urement of the New Inter ity Fleet trains and the requirement to adequately maintain these trains. The Kangy Angy site (this Proje t) is a priority site due to its ability toimprove urrent train operations a ross the Sydney metropolitan network.

Currently inter ity trains are maintained at Flemington Maintenan e Centre with periodi major overhauls undertaken at Auburn. Inter ity trains are urrently stabled at a number of lo ations, in luding Flemington, Eveleigh, Mount Vi toria, Lithgow, Gosford, Broadmeadow, New astle, Port Kembla and Wollongong. As part of the pur hase of the NIF trains, the development of an en losed maintenan e fa ility (this Proje t) is to provide a dedi ated spa e for the NIF rolling sto k tobe maintained.

1.2 Project Descriptio

The Proje t will be lo ated at Kangy Angy (the site) within the Central Coast Lo al Government Area (LGA) some 63 km north of the Sydney CBD (Figure A-1). The proje t site is lo ated on the down tra k side of the Main North Line, between Tuggerah and Ourimbah railway stations. The site is bordered by the Main North Rail line to the south east, Or hard Road to the north west, Ourimbah road tothe south west and private property to the north east.

TfNSW is delivering a new train maintenan e fa ility at a site in Kangy Angy on the Central Coast of NSW to support he pro urement of the New Inter ity Fleet. The fa ility will undertake light and heavy maintenan e a tivities for the new fleet of trains. The new fa ility will in lude about six kilometres of ele trified railway, andwill be seven tra ks wide at its widest point, will over an area of approximately 500,000 square metres bounded by a perimeter fen e. The general site layout is provided on Figure A-2.

The key omponents of this fa ility in lude:

• Maintenance facility ele ents: • Fleet aintenance building. • Six standing roads (for aintenance works on the train sets and to hold trains). • One standing road for wheel lathe operations. • Auxiliary workshops electronic. • Clean roo . • Material storage (including fla able liquid storage). • Wheel lathe. • Auto atic train wash. • Site access roads. • Miscellaneous buildings: • Ad inistration facilities. • Signalling building. • Security building.


Facility Groundwater and Dewatering Management Plan | Project Team | Revision H SMEC Aus ralia | Page 6

• Co pressed air building. • Water treat ent plant. • Substation building power supply (traction power, bulk power, signalling power supply). • Other infrastructure including: • New railway track infrastructure on the western side of the existing rail corridor to allow for trains to enter and exit the aintenance facility site fro the Main North Line.

• A new rail bridge (consisting of two separate structures) over Chittaway Creek and Turpentine Road.

• A new access roadway and bridge to the aintenance facility site off Enterprise Drive. • A new flood access road between Orchard Road and the proposed new access roadway.

• A series of detention ponds • Staff car park. • Relocation of existing high voltage (HV) power trans ission lines (Ausgrid and Sydney Trains HV assets).

• Co bined services route (i.e. rail related utilities such as power, co unications and signalling cables).

A Review of Environmental Fa tors (REF), Spe ies Impa t Statement (SIS) and Additional Spe ies Impa t Statement were prepared in a ordan e with the requirements under the Environ ental Planning and Assess ent Act 1979 (EP&A A t) and the former Threatened Spe ies Conservation A t 1994 (TSC A t). To support the Proje t determination, approval was sought and re eived under Se tion 130(1) and 133 of the Environ ent Protection and Biodiversity Conservation Act 1999 (EPBC A t). The New Inter ity Fleet Maintenan e Fa ility, Kangy Angy, NSW (EPBC 2016/7681) approval (Appendix B) requires a Groundwater Management Plan to be prepared and implemented for the Proje t (EPBC Approval Condition No. 2). EPBC Approval Condition No. 2 requires the preparation and implementation of a Groundwater Management Plan, and the preparation of a Flood Impa t Assessment and Groundwater Assessment to minimise impa ts of the Proje t on Groundwater Dependent E osystems (GDEs) that support or may support Melaleu a bi onvexa lo ated on and offsite.

This Groundwater and Dewatering Management Plan has been prepared to satisfy the requirements of EPBC Approval Condition No. 2.

The justifi ation and need to the Proje t is outlined in Se tion 2 of the Review of Environmental Fa tors (REF) Vol

1.3 Purpose of Pla

The purpose of this plan is to:

1. Provide a referen e guide for the management of groundwater during onstru tion and operation of the fa ility;

2. To minimise potential impa ts to groundwater dependent e osystems (GDE’s) and other benefi ial uses i.e. nearby registered groundwater bores;

3. Comply with the Conditions of Approval listed in the New Inter ity Fleet Maintenan e Fa ility Proje t Determination Report (August 2017), in parti ular the requirements of the EPBC Approval Condition No.2; and

4. Comply with statutory or legislative requirements as they apply, i.e. Water Management A t 2000.



1.4 Risk to Grou dwater

In general, the potential permanent hanges to groundwater quality and level are not anti ipated to be signifi ant with the lo al system finding a new equilibrium post onstru tion.

In dry periods the water table naturally de lines therefore inflows to ex avations will be minimal and onstru tion impa ts will therefore be minimal or will de rease a ordingly. During periods of high rainfall, the water table naturally in reases and inflows to ex avations will in rease a ordingly. However, during wet periods there is in reased re harge a ross the entire aquifer system and the in reased re harge offsets any potential drawdown (and quality) impa ts due to dewatering.

The overall potential risks related to groundwater in lude;

• Risk to the project due to groundwater i.e. inflows, dewatering, construction i pacts; • Risk to groundwater para eters due to the project (conta ination, reduced flow, changes in quality);

• Indirect Risk to GDE’s and other beneficial uses.

These risks an be further divided based on the Constru tion Phase and the Operational Phases.

1.4.1 Co structio Phase

The main risks to / from groundwater during the onstru tion phase in lude:

• Land clearing and subsequent changes to recharge and recharge water quality; • E bank ents and paved areas resulting in changes to recharge and flow paths; • Excavations below the water table that require dewatering and disposal; • Groundwater conta ination fro che ical and hydrocarbon spills; • Construction of detention basins resulting in changes to recharge and flow paths; • Degradation of known GDE’s and beneficial uses (nearby water bores) fro above activities.

1.4.1.1 La d cleari g

Land learing and surfa e earthworks will expose the area to different infiltration rates whi h may hange the rate of rainfall re harge and may temporarily in rease dissolution of ions impa t groundwater quality. These types of impa ts are usually short lived.

1.4.1.2 Emba kme ts a d paved areas

Embankments and paved areas will redu e the amount and distribution of re harge and may hange groundwater flow paths and quality.

1.4.1.3 Excavatio s below the water table

Ex avations below thewater table may require dewatering whi h may lower the water table in the lo al area and provides a window into the aquifer potentially shortening any ontamination flow paths. Pumped groundwater will be required to be disposed and if ontaminated may pose a risk to the re eiving environment.

As groundwater inflows are towards the ex avation, hanges to groundwater quality are anti ipated to be aptured by the ex avation and not enter the down-gradient groundwater system. As long as dewatering drawdowns are within the natural groundwater flu tuation ranges the impa ts to quality are expe ted tobe negligible.



1.4.1.4 Co tami atio

Contamination of the groundwater an o ur through fuel, oil and hemi al spills and sewage leakage. Spills may o ur during refuelling operations, maintenan e or servi e of onstru tion equipment, leaning operations or sewage leaks.

1.4.1.5 Dete tio basi s

Detention basins will be used to alleviate downstream flooding and to treat surfa e runoff. Due to the shallow water table, basins may be very lose to or interse t the water table and a t as lo alised re harge sour es. Any ontamination washed into the basins during rainfall events may have a shortened pathway to groundwater.

1.4.1.6 Degradatio of GDEs

The above dire t groundwater risks are also deemed to have an indire t potential impa t to the two known GDEs that o ur on the site. GDEs are defined as those ‘ecosyste s that require access to groundwater to eet all or so e of their water require ents so as to aintain their co unities of plants and ani als, ecological processes and ecosyste services’. GDEs require groundwater to maintain their omposition and fun tioning. The removal or hange in groundwater availability or quality will influen e the omposition, stru ture and fun tion of these e osystems.

As outlined in the REF, two plant ommunities within the Proje t site were determined as being GDEs. These onsist of:

• Melaleuca biconvexa – Swa p Mahogany – Cabbage Pal Forest• Jackwood – Lilly Pilly – Sassafras Rainforest

1.4.1.7 Be eficial Uses

Benefi ial uses in lude the use of a tive nearby residential shallow aquifer “water bores” for both domesti and agri ultural use.

The above identified dire t impa ts to groundwater (espe ially the interferen e/ hange to aquifer re harge and quality) have the potential to ause degradation and eventual loss of these e osystems along with the fauna dependant on these plant ommunities. With regards to benefi ial uses, the risk lies with potential loss of groundwater availability and quality.

1.4.2 Operatio al Phase

The potential risks to groundwater quality during operation of the fa ility in lude:

• Conta ination fro the stor water detention basins;• Increased point source recharge causing localised flooding or water logging;• General site conta ination fro the operation of the facility.

As per Se tion 7.10.3 of the Proje t REF, there will be no new or residual ex avations that would require dewatering through pumping during the operation of the fa ility and therefore it is onsidered to be a negligible potential impa t to groundwater during operational a tivity.

The primary impa t to groundwater level during operations would be due to the under tra k drainage system. In general:

• The tra k is being onstru ted primarily on fill embankments, water draining into theunder tra k drainage will be surfa e water;

• Where the under tra k drainage system is required to fall below the design groundwaterlevel, blank (i.e. non-slotted) pipe shall be used to prevent groundwater ingress; and

• Groundwater ingress to the under tra k drainage system may o ur during periods ofhigh groundwater. At these times, the water re harge to the GDE would be high and


Facility Groundwater and Dewatering Management Plan | Project Team | Revision HSMEC Aus ralia | Page 9

flow through the drainage system would also be high, hen e the risk to GDE from lower water levels or ontamination would be minimal.

The operational risks to groundwater are asso iated with ontamination from potential hemi al and fuel spills (as perSe tion 7.10.4 of the REF). This risk will be managed through the implementation of the maintenan e fa ility operators spill response pro edure, whi h will form part of the Operational Environmental Management Plan (as per TfNSW Condition of Approval No.14).

As done during the onstru tion phase, during the operation of the fa ility hazardous materials pro edures, in luding pro edures for managing spills and refuelling will be implemented to minimise risks of groundwater ontamination from hemi al spills orleaks.

Operational requirements will be reassessed in the development of the OEMP using groundwater monitoring results during baseline and onstru tion phase. Baseline monitoring does not indi ate existing ontamination onsite. In the event of a spill the groundwater monitoring program would be adjusted to in luded targeted analysis to assess a spills potential impa t to the groundwater system.

1.4.2.1 Dete tio basi s

The storm water detention basins may allow enhan ed re harge through their base. Any ontamination entering the basins may enter the groundwater system. Due to the ex avation of the basins below natural ground level the base may interse t the water table shortening the flow path. Detention basins that interse t the aquifer are to be lined to minimise the risk of ontamination and minimise the volume of groundwater seepage.

1.4.2.2 Localised grou dwater mou di g

The detention basins may a t as lo alised re harge sour es whi h may in rease the lo al water table elevation. This may lead to water logging and/or salinization issues.

1.4.2.3 Ge eral site co tami atio

Operation of the fa ility for its intended purpose will involve train movements, maintenan e, and repair, some manufa turing and leaning, general vehi le movements and amenities infrastru ture. All these may be potential sour es of ontamination.

1.4.3 Risk Assessme t

The identified risks to groundwater have been rated in a ordan e with a stru tured framework, outlined in Table 1-1 to Table 1-3 below.

Table 1-1: Risk Fra ework

Co seque ce

1. Mi or 2. Moderate 3. High 4. Major 5. Critical

d

5. Highly

LikelyMedium High High Severe Severe

ike

oo

lih 4. Likely Low Medium High High Severe

3. Possible Low Medium Medium High Severe

L

2. U likely Low Low Medium High High

1. Rare Low Low Low Medium High



Table 1-2: Likelihood and c onsequence

Qualitative measure of likelihood (how likely is itoccur after ma ageme t actio s have bee put

that this eve t/circumsta ces will i place/are bei g impleme ted)

Highly likely Is expe ted to o ur in most ir umstan es

Likely Will probably o ur during the life of the proje t

Possible Might o ur during the life of the proje t

Unlikely Could o ur but onsidered unlikely or doubtful

Rare May o ur in ex eptional ir umstan es

Qualitative measure of co seque ces (what will be issue does occur)

the co seque ce/result if the

Minor Minor risk of failure to a hieve the plan’s obje tives. Results in short term

delays to a hieving plan obje tives, implementing low ost, well hara terised orre tive a tions.

Moderate Moderate risk of failure to a hieve the plan’s obje tives. Results in short term delays to a hieving plan obje tives, implementing well hara terised, high

ost/effort orre tive a tions.

High High risk of failure to a hieve the plan’s obje tives. Results in medium-long

term delays to a hieving plan obje tives, implementing un ertain, high ost/effort orre tive a tions.

Major The plan’s obje tives are unlikely to be a hieved, with signifi ant legislative, te hni al, e ologi al and/or administrative barriers to attainment that have no

eviden ed mitigation strategies.

Criti al The plan’s obje tives are unable to bea hieved, with no eviden ed mitigation

strategies.

Table 1-3: Risk assess ent and controls

Likelihood

Risk

Co

seque ce

Co seque ce Co trol Measures Residual Risk Risk Ow er

Fuel spills Dedi ated refuelling during 3 4 12 Medium sites, store fuels in Fuel spills Contra tor

onstru tion bunded areas

Fuel spills Dedi ated refuelling during 3 4 12 Medium sites, store fuels in Fuel spills Operator

operations bunded areas

Line detention ponds, limit the rate

Groundwater of groundwater

Groundwater Mounding

4 2 8 Medium infiltration, pla e ponds / re harge

Mounding Designer

tren hes in area of high permeability



Risk

Lik

elih

oo

d

Consequence

Co

nseq

uen

ce

Control Measures Residual Risk Risk Owner

Minimise earth work Water quality during wet periods,

changes during

4 2 8 Medium ensure recharge

water is of Water quality

changes Contractor

construction appropriate quality, follow this plan

Water quality changes during

operation

4 2 8 Medium Continue monitoring during operations,

follow this plan

Water quality changes

Operator

Groundwater inflows to Follow good practice Groundwater

excavations 5 1 5 Medium when working in inflows to Contractor causing excavations. excavations

instability

General site Dedicated refuelling contamination

during 3 3 9 Medium

sites, store hazardous materials

General site Contamination

Contractor

construction in bunded areas

General site Dedicated refuelling contamination

during 3 3 9 Medium

sites, store hazardous materials

General site Contamination

Operator

operation in bunded areas.

Restrict inflows to excavations,

Water table drawdown

3 4 12 High recharge the water table with pumped water, Minimise the

Water table drawdown

Contractor

time excavations are open and dewatered

Adequate

Groundwater Disposal

contamination, water logging,

insufficient capacity

5 3 15 High

assessment during design phase, appropriately

designed disposal facilities (trenches,

ponds), monitoring of quality, adequate

cleaning / settlement

Water logging, Water quality

changes, inability to dispose required volume

Contractor Operator, Designer

and storage times

Degradation / loss of GDE’s

2 4 8 High GWDMP, monitoring

and assessment (Vegetation health

Loss of habitat

Contractor/Operator


Facility Groundwater and Dewatering Management Plan | Project Team | Revision H SMEC Australia | Page 12

Risk

Likelihood

Co

Co

seque ce

seque ce Co trol Measures Residual Risk Risk Ow er

(due to GW and groundwater) impa ts) throughout the

onstru tion and operation phase, implementation of

CEMP and OEMP

Impa ts to Benefi ial Use (registered

bores) during 1 3 3 Low

GWDMP, base line bore survey

Claims against the proje t

Contra tor

onstru tion

Impa ts to Benefi ial Use

GWDMP, base line Claims

(registered 1 3 3 Low bore survey, onstru tion

against the Operator bores) during

operation monitoring program

proje t



2 Regula ory Con ex

2.1 Co ditio s of Approval

The proje t has been granted both State and Commonwealth planning approval under Part 5 of the Environmental Planning and Assessment 1979 (EP&A A t) and under Se tions 130(1) and 133 of the EPBC A t respe tively, see Appendix B. The spe ifi onditions of approval whi h relate to Groundwater are provided below.

2.1.1 Conditions Atta hed to the Approval:

State

New Inter ity Fleet Maintenan e Fa ility Determination Report, #57 Groundwater Assessment:

• “A detailed Groundwater Assess ent is to be developed as part of, but prior to the finalisation of the detailed design process undertaken to confir the potential i pacts of the Project on local and regional groundwater conditions. The groundwater assess ent shall identify anage ent and itigation easures to be i ple ented to ensure that groundwater i pacts are appropriately anaged”.

The groundwater assessment shall be prepared in onsultation with the NSW Department of Industry Land and Water Division (DPI), WaterNSW and Central Coast Coun il, and in lude onsideration of impa ts toadja ent GDE’s.

Commo wealth

Conditions atta hed to the above State Approval.

To minimise the impa ts of the a tion on Groundwater Dependent E osystems that support or may support Bi onvex Paperbark lo ated onsite and offsite, the person taking the a tion must implement Conditions 51 and 52 of the State Conditions of approval and must prepare and implement:

• Groundwater and Dewatering Management Plan as des ribed in se tion 7.10.4 of the review of environmental fa tors, and

• The Groundwater and Dewatering Management Plan must be submitted to the Department at least 1 month before onstru tion ommen es, and onstru tion annot ommen e until the plan is approved by the Minister.

Note: The above referen e to Conditions 51 & 52 of the State Conditions hanged in the final Determination Assessment to State Conditions 56 & 57. Condition 56, relates to Flood Impa t Assessment.

In relation to monitoring of groundwater, the Department of the Environment and Energy (DoEE) Guideline for “Groundwater and Dewatering Manage ent Plans (GWDMP)” requires the plan to be approved prior to the start of onstru tion. The GWDMP requires the following to be addressed:



Table 2-1: Department of the Environment and Energy (DoEE) Guideline for “Groundwater Management Plans

Groundwater Management Plan (GWMP) (derived from EMP

Guidelines)

Where

addressed in

GWDMP

1. The program includes an executive summary which states the relevant approval conditions, expands upon the purpose of the program, and outlines the primary strategies to manage key risks to program objectives.

Executive Summary

2. The program sufficiently describes the project so as to give context to the purpose of the program, and includes: a) the location and nature of project activities and timeframes; b) environmental information for these locations; and c) details relevant to specific approval conditions.

Section 1 and Section 2

3. The program describes the purpose of monitoring and its functional relationship to operational decisions.

Section 1.3

4. The program implements monitoring and reporting guidelines in the National Water Quality Management Strategy (NWQMS). The program: a) delineates NWQMS environmental values of relevant waters; b) includes baseline data and information on current biological, water

quality and flow of those waters; c) identifies and describes potential water quality and flow hazards; d) evaluates the risks and quantifies cumulative effects; e) includes threshold triggers and/or guideline values to protect MNES;

and f) includes biological, chemical and flow monitoring and assessment

procedures.

Table 10

5. The program states monitoring objectives to meet operational decision-making. To this end the program, for each objective: a) specifies the variables to be measured, the state and/or rate of

change, the precision and confidence, the spatial resolution and time scales required to inform operational decision-making; and

b) includes ‘early-control’ (that management actions are effective) and ‘early warning’ (corrective actions are required) functions, to inform timely decisions on corrective actions.

Section 4,

a) 4.3

Section 5

6. The program describes the monitoring methods that will be implemented, and: a) includes quantitative (e.g. on-ground survey results) and qualitative

baseline data (e.g. analysis of water quality) that establish the start quality/condition of the environment;

b) describes the sampling strategy (including monitoring area, site selection and sampling intensity over space and time) and statistical analyses to be employed;

c) justifies the sampling strategy/monitoring methods, including through the likely statistical power delivered by the strategy/method;

d) field and laboratory quality control/assurance program; e) justifies the monitoring methods to be used, including:

Section 4 and 5

a) 5.4

b) 5.2, 5.3, 5.4

c) Section 7.

d) Section 6

e) 7.2, 7.3

f) 4.3

g) 5.4.2



http:decision-making.To

Grou dwater Ma ageme t Pla (GWMP) (derived from EMP

Guidelines)

Where

addressed i

GWDMP

• an assess ent of effectiveness and constraints to use; • capacity to detect change in environ ental condition due to the project; f) ommits to engage appropriately qualified experts to design and

ondu t monitoring and survey a tivities, and analyse monitoring results; and

g) the lo ation, nature and number of monitoring sites, in luding ben hmark/referen e sites to dete t proje t attributable impa ts ( .f. seasonal variation).

7. The program assesses the risk of failure to a hieve the program’sobje tives. To this endthe program: a) states the program obje tives; b) identifies events or ir umstan es that prejudi e the program’s

obje tives. The events or ir umstan es must addresss ientifi /e ologi al un ertainty, sto hasti events and legal/landuse planning fa tors thatmay represent risks;

) in ludes a qualitative assessment of the likelihood and onsequen e of those events or ir umstan es, and the residual

risk of failure to a hieve those riteria due to identified events or ir umstan es;

d) hara terises risk as low, medium, high or severe, and derived from likelihood (highly likely, likely, possible, unlikely, rare) and

onsequen e (minor, moderate, high, major and riti al); and e) explains how onsequen e, likelihood and risk level for ea h risk

have been determined.

8. The program ma ages the risk of failure by: a) enhan ing monitoring and management a tivities for high risk

events or ir umstan es, thereby providing a ‘margin of safety’ to dete t, avoid or mitigate the likelihood and/or impa ts of the event or ir umstan e;

b) spe ifying management triggers (measurable events orir umstan es) that dete t a tual or potential issues in a timelymanner to avoid, minimise or mitigate adverse impa ts;

) ensuring the monitoring program in ludes a tivities to dete t management triggers, and explaining how monitoring a tivities may

inform thesele tion andimplementation of orre tive a tions; d) detailing effe tive ontingen y responses and orre tive a tions

that may be implemented if a management trigger is realised; and e) monitoring the effe tiveness of orre tive a tions and implementing

a ‘stop work’ response in the event orre tive a tions are noteffe tive.

9. The program ide tifies a d ma ages u certai ty. To this end theprogram spe ifies: a) key data/information used to formulate the program; b) the limitations and/or un ertainty asso iated with the use of that

data/information; and ) how limitations and/or un ertainty, and asso iated risks, are

mitigated during program implementation. For example, where a margin of safety is applied to management measures until

a) 1.3.1

b) 1.4

) 1.4.3

d) 1.4.3

1.4.3

7.2

7.3

9



Where Grou dwater Ma ageme t Pla (GWMP) (derived from EMP

addressed i Guidelines)

GWDMP

un ertainty is redu ed to an a eptable level or performan e targets are attained/maintained.

10.The program in ludes a data ha dli g program for data storage and prote tion, data extra tion, quality ontrol, analysis, interpretation,

reporting and presentation. Data ownership and distribution, availability and li ensing to the Department for omplian e and re overy planning purposes, must be spe ified. Timelines for the data handling, analyses

and delivery should be spe ified.

11.The program outlines a periodic tech ical review a d evaluatio of the program and the likely omposition of the review ommittee(s).

12. The program is required under EPBC Act approval co ditio s, and in ludes a table ontaining:

a) approval ondition requirements; b) se tion and page numbers whi h address the approval onditions; ) key ommitments for meeting ea h ondition requirement.

13. The program in ludes a s hedule and triggers for auditi g the implementation and effe tiveness of the program, and outlines auditable

systems forre ording program implementation.

14. The program in ludes an adaptive impleme tatio program to ensure un ertainty is redu ed over time, and that program obje tives are

a hieved. The program therefore in ludes arrangements for: a) ensuring new data/information is olle ted and in orporated into the

program, as a result of implementing the program and from new information derived from external sour es (e.g. a ademi literature,

EPBC poli y statements); b) effe tively oordinating, s heduling and/or triggering monitoring,

risk management, auditing and reporting a tivities; ) periodi ally reviewing risks, in luding in response to the risk level,

hanging ir umstan es or the results from implementing ontingen y responses;

d) frequent review ofthe effe tiveness of management measures with signifi ant levels of un ertainty, relatively long implementation

timeframes, and upon whi h the program is highly dependent; e) addressing the onsequen es of signifi ant environmental in idents

(pre-determined and unanti ipated); and f) reviewi g the program under the following ir umstan es:

• perfor ance reports indicate perfor ance targets ay not be achieved; • according to approved ti efra es; and • the i pacts of significant environ ental incidents.

15. The program spe ifies reporti g commitme ts, in luding: a) reporting required under EPBC onditions of approval; b) an outline of the standard report ontent; and ) a s hedule and triggers for reporting.

16. The program spe ifies accou tabilities for implementing the program, in luding risk management, reporting, review and auditing.

5.5

5.6

9

This table and Table 9

Table 9

5.4

5.4, Table 9

Table 9



Grou dwater Ma ageme t Pla (GWMP) (derived from EMP

Guidelines)

Where

addressed i

GWDMP

17. Maps, pla s, figures, images and sectio s used in the plan: a) shows the monitoring area in a state and regional ontext; b) must be learly legible, in luding fine print, when printed on A4; ) shows areas with differing environmental ondition or quality; d) shows the lo ation of stati monitoring plots and/or the general

lo ation of random monitoring/survey a tivities that will be undertaken;

e) are s aled to enable the reader to learly identify, based on lo al landmarks (trees, fen es, stru tures) the lo ation of management features being shown on the map;

f) in lude appropriate standard metri s ales to represent the information (for example 1:100 000). Datum – plans and ross se tions refer to AHD;

g) have metri measurements, graphi bar s ales, lo al grid lines and standards and north point or orientation of se tions (in lude a key) are used throughout; and

h) in lude title blo ks in the lower right hand orner with the following information: EPBC number and proje t name, title and number of the plan, author, s ale, date, sour e and date of data.

18. The program refere ces scie tific, legal or other claims or stateme ts that support the effe tiveness of the program, e.g. referen es to s ientifi literature, published guidelines, legislation, onservation advi e, re overy plans, threat abatement plans.

19. The program uses the terms ‘will’ and ‘must’ when ommitting to a tions, instead of ‘where possible’, ‘as required’, ‘to the greatest extent possible’, ‘should’ or ‘may’.

20.The footer or header of ea h page of the program states the name of the proje t, EPBC #, date of the program and sequential page numbering.

21. The program in ludes a glossary of terms omprised of a ronyms, terms open to different interpretations, not in ommon use, te hni al or defined in the approval onditions.

22. The program in ludes risk assessment and management, monitoring and reporting s hedules prepared in a ordan e with Appendix A.

Appendix A

10

Whole Do ument

Whole Do ument

Page i

1.4.3

Further spe ifi requirements may be added subje t to the Minister’s onditions of approval.

2.1.2 Lice si g

2.1.2.1 Mo itori g bores

Intera tions, a ess and /or impa ts to groundwater require NSW State li ensing or approvals or both prior to intera ting with it.

A Water A t 1912 li en e is no longer required for monitoring bores that are:

• Associated with State Significant Develop ent, State Significant Infrastructure and Public Priority Infrastructure Projects; o r



• Located outside of the Great Artesian Basin, that are less than 40 deep, provided they are constructed in accordance with the Mini u Construction Require ents for Water Bores in Australia 2012.

• Any ‘bored’ investigation that is greater than 3 below the surface or encounters or has the potential to encounter groundwater ust be conducted in ac cordance with the “Mini u Construction Require ents for Water Bores in Australia “3rd Ed 2012 (Federal legislative docu ent) and any State specific require ents. This includes but is not li ited to the following:

• Ensuring drilling ac tivities do not cause har to the gr oundwater environ ent; • Including avoiding interconnection of separate aquifers; • Spreading conta ination or interconnecting conta inated and non-conta inated aquifers

• Construction of bores in accordance w ith required s tandards; and • Deco issioning of boreholes in accordance with Mini u Construction Require ents for Water Bores in Australia. Note: this applies to geotechnical boreholes that hav e intersected o r the potential to i ntersect groundwater not just water bores.

The Proje t is lo ated outside the Great Artesian Basin and has bores that are less than 40m deep and will therefore not require monitoring bore approvals to drill or li ensing, but all bores must be onstru ted in a ordan e with the Minimum Constru tion Requirements for Water Bores in Australia 2012.

2.1.2.2 Dewateri g

Dewatering a tivities will be undertaken during onstru tion and a li ense is required under the NSW Water Manage ent Act 2000 . An appli ation for groundwater dewatering has been submitted to WaterNSW. This appli ation is pending assessment of the potential dewatering volumes as part of the detailed design phase. This se tion will be updated when the appli ation is approved.

Disposal of dewatering water may also require a li ense under the NSW Protection of the Environ ent Operations Act (1997) for dis harge of water from a point sour e, the proje t is investigating whether this is required.



3 Hydrogeological Se ing

3.1 Hydrogeology

The proje t site is lo ated on the south eastern side of Ourimbah Creek with Chittaway utting a ross the southern end of the site and Bangalow Creek to the south west. The majority of the site sits on a slightly elevated hill adja ent to the Ourimbah Creek flood plain.

3.1.1 Aquifers

The site is underlain by quaternary alluvium and Terrigal Formation bedro k. These two geologi al units form two separate aquifer systems:

• Quaternary Alluviu for s an unconfined, low to oderate per eability shallow water table aquifer consisting of sand, gravel and silty clays.

• Terrigal For ation for s an unconfined to confined low per eability aquifer with groundwater flow ainly through secondary per eability. The for ation is described as interbedded silt and fine sandstone, shale, and fine to coarse grained quartz to quartz-lithic sandstone w ith inor red sandstone.

3.1.2 Recharge a d Discharge

Groundwater re harge to both aquifers is through rainfall infiltration. The alluvial aquifer may also re eive re harge from surfa e flows. Groundwater dis harge o urs through evapotranspiration, baseflow to reek and groundwater pumping. Groundwater may also transfer from the underlying Terrigal Formation to the alluvium where a positive head exists.

3.1.3 Gradie t a d Flow D irectio

The groundwater level is expe ted to be a subdued version of topography with flow from areas of higher elevation towards the drainage lines. Gradients within the alluvium are expe ted to be relatively small due to the high permeability. The gradient within the Terrigal Formation may be mu h higher in the surrounding hills, espe ially to the south and southeast of the site.

Within the site boundary groundwater flows are predominantly towards Bangalow and Ourimbah Creeks to the west, north and north east. Groundwater may move from the higher ground to the south and south east through the site and likely onstitutes upgradient flow in the Tuggerah Formation. Within the alluvial aquifer upgradient ba kground water may be en ountered south west of the site.

The interpreted groundwater elevation, based on observations in the geote hni al data report (Coffey 2016), is shown on Figure A-5 for the shallow alluvial / olluvium / residual soil aquifer. The Terrigal Formation and asso iated deeper groundwater aquifer is not anti ipated to be interse ted.

3.1.4 Depth to Water

Groundwater levels have been re orded in a series of open standpipe piezometers installed during the on ept design phase investigations (Coffey 2016) and additional standpipes by SMEC in 2018, reported in the groundwater monitoring report NIF-SMEC-RPT-GE360002.

The water table under the site is noted as being generally shallow, with groundwater ranging from the existing ground surfa e to approximately 6.26 (BH01) meters below ground level (mbgl). The groundwater elevation ranges from 3m AHD to 13.37m AHD. The site generally sits above the 10m AHD ontour.

The baseline monitoring results show a large natural variation in groundwater level linked to limati trends. Review of the data showed water levels near ground surfa e following a period



of above average rainfall in early 2016. The 2018 monitoring shows lower groundwater levels (up to 3m lower) following a trend of lower rainfall.

3.1.5 Grou dwater Quality

Water quality information from registered bores indi ates groundwater is relatively fresh in the alluvial aquifer and generally fresh to slightly bra kish in the Terrigal Formation.

Con ept design stage durability analysis (Coffey 2016) indi ates (BH1, 3, 5 and 19) the following:

• pH – 4.9 to 5.8 • EC (µS/c ) – 240 to 460 • Sulphate ( g/L) – 14 to 77 • Chloride ( g/L) – 5.8 to 55

The SMEC 2018 baseline groundwater quality sa pling rounds show the following ranges:

• pH – 4.4 to 6.2 • EC (µS/c ) – 138 to 1420 • Sulphate ( g/L) – 3 to 189 • Chloride ( g/L) – 28 to 424

3.1.6 Grou dwater Depe de t Ecosystems

As stated in Se tion 1.4.1.6, the REF e ologi al studies identified two plant ommunities within the Proje t site as being groundwater dependent onsisting of the following:

• Melaleuca biconvexa – Swa p Mahogany – Cabbage Pal Forest • Jackwood – Lilly Pilly – Sassafras Rainforest.

From a groundwater perspe tive, the proje t may impa t the above identified GDE’s on site. Within the proje t boundary land learing will remove vegetation from these GDE’s and land modifi ations may hange the hydrogeologi al regime however, any dewatering during onstru tion will be temporary.

The lo ation of three GDE ex lusion zones relative tothe proposed infrastru ture is shown on Figure A-2.

Further details of regarding GDE’s are dis ussed in Se tion 4.

3.1.7 Be eficial Use

The REF (TfNSW 2016) identified 23 registered groundwater bores within approximately one kilometre of the site. However, the REF stipulates that only two of the nearby bores (GW078813 and GW067278) are in the shallow aquifer and only pose a potential for some impa t as they are in lose proximity to the main building, where dewatering is expe ted. The impa t is onsidered negligible as the groundwater levels at these bores are between approximately three and six metres below ground level and the maximum depth of ex avation at the main building is approximately two metres below ground level.

Dewatering has anestimated maximum radius of influen e of 60m, under the worst ase (e.g. high water table and high permeability). During these times re harge is anti ipated to offset any drawdown and the hange in groundwater level at the private bore lo ations is expe ted to be minimal and likely not dis ernible from natural variations.

In addition, the groundwater in the ex avation area appears to be semi isolated from the main alluvial flood plain groundwater asit forms a slightly elevated mound with flow outwards tothe south west, west, north and north east. The impa ts of any dewatering are anti ipated to be minimal due to this slight groundwater mound and there is minimal to no through flow from up



gradient. Most private bores are lo ated at lower elevations to the site with a deeper depth to water. Removal of water from a higher elevation may redu e the re harge to the system down-gradient however the area of the site is signifi antly smaller than the overall re harge area. The private bore losest to the ex avation area has been pur hased by the proje t.

Where registered bore owners are willing to parti ipate, a bore survey of the above two bores (and any other nearby registered bores onsidered to be potentially impa ted) will be arried out to assess the status of these registered bores. Registered bore lo ations are shown on Figure A-4.

3.1.7.1 Registered bore status

To be updated after bore survey.



4 Groundwa er Dependen Ecosys ems

4.1 Summary

The proje t is due to impa t 26.6 he tares of Swamp Forest GDE (WSP, 2017) in the form of two plant ommunity types that onform to the Swamp Forest GDE:

• Melaleuca biconvexa – Swa p Mahogany – Cabbage Pal Forest • Jackwood – Lilly Pilly – Sassafras Riparian War Te perate Rainforest.

In addition, the ground water dependent spe ies Melaleuca biconvexa, listed as vulnerable under the Biodiversity Conservation Act 2016 and Environ ent Protection and Biodiversity Conservation Act 1999, is present on site. Approximately 1,030 Melaleuca biconvexa individuals are due to be retained onsite in distin t prote tion areas, shown in Figure A-2.

All vegetation monitoring during and after onstru tion shall be ondu ted in a ordan e with the Flora and Fauna Management Plan (FFMP). As part of the vegetation monitoring ondu ted an e ologist shall provide an overall assessment on GDE’s health in a ordan e with the FFMP.

Condition monitoring of the retained stands of Melaleuca biconvexa will be ondu ted in the form of a BACI (Before After Control Impa t) monitoring program.

The threatened frogs, Mahony’s Toadlet (Uperoleia ahonyi) and Wallum Froglet (Crinia tinnula), are onsidered to be sensitive to ground water hanges (being adapted to a id swamp onditions) and foraging and shelter habitat will be impa ted in the form of learing 13.8 he tares of Mahony’s Toadlet habitat and 2.4 he tares of Wallum Froglet habitat. A monitoring program will be ondu ted for these spe ies and is detailed in the Conservation Management Plan (CMP) for Mahony’s Toadlet and Wallum Froglet. As part of the monitoring, management triggers are proposed. Further remedial a tions are proposed should management measures implemented as part of the proje t be found notbe su essful.

4.2 Mo itori g for Grou dwater Depe de t Ecosystems

Quantitative monitoring of terrestrial biodiversity values with potential to be impa ted will be undertaken in the proje t area using a modified Before-After Control-Impa t (BACI) design. Data olle ted as a part of the proje t Spe ies Impa t Statement will be supplemented with additional monitoring prior to dewatering to provide a baseline. Additional survey will be undertaken during onstru tion at maximum six month intervals and for a suitable period during operations. The duration of operational monitoring is determined based on results of annual analysis of data as well as observed impa ts to surfa e features and other monitoring (e.g. groundwater). If data analysis indi ates hanges are o urring, impa ts to surfa e features are observed or hanges to other monitoring programs indi ate impa ts may have or are o urring, monitoring will ontinue for a suitable period, determined in onjun tion with TfNSW.

Data is olle ted at ontrol (referen e) site in the same manner and for the same duration as impa t sites. Control sites are those that are to have a low likelihood of impa t due to the proje t. This site provides data against whi h potentially impa ted sites an be analysed. The use of ontrol sites allows us to distinguish between impa ts asso iated with the proje t and those asso iated with broader environmental and anthropomorphi variables (observed at both ontrol and impa t sites).

The lo ation of the ontrol site is the northernmost GDE ex lusion zone as shown in Figure A-2.

Monitoring of the following biodiversity values in the retained areas proje t area and referen e sites will be undertaken annually in the following areas:



• One vegetation plot in each retained area of Melaleuca biconvexa – Swa p Mahogany – Cabbage Pal Forest and Jackwood – Lilly Pilly – Sassafras Riparian War Te perate Rainforest;

• Retained and translocated Melaleuca biconvex; and • Mahony’s Toadlet and Wallu Froglet.

GDE Mo itori g

Impa ts to GDE vegetation may be eviden ed by a hange to the number of spe ies at different sites, or an overall hange in the spe ies omposition, as some spe ies may be less affe ted than others. In affe ted areas, these impa ts may manifest asthe following:

• Change in floristic Total Species Richness (TSR): the nu ber of individual species and is calculated by su ing the total nu ber of unique species detected at each onitoring point during each season and year. This is a si ple presence-absence easure and does not account for the relative abundance of each species; and

• Changes in the floristic species co position: the asse blage of different individual plant species that ake up a vegetation co unity.

Data is analysed statisti ally by al ulating the TSR for ea h monitoring site through the sum of the number of spe ies dete ted at ea h transe t for ea h survey. Exploratory data analysis of this data is then undertaken whi h involves the plotting on a graph of the TSR for ea h survey year from when monitoring first ommen ed up to the urrent date of data olle tion to provide a visual indi ation of trends between impa t and ontrol sites, as well as trends prior to and following onstru tion. To formally quantify whether trends dete ted visually represent a tual hanges in TSR, generalised linear mixed models (Bolker et al. 2009) are then tested for all sites.

Trends in floristi spe ies omposition is analysed at ea h transe t within GDE’s to determine whether there is a shift in the type of spe ies dete ted before onstru tion and following onstru tion.

As part of the vegetation monitoring ondu ted an e ologist shall provide an overall a qualitative health assessment of the GDE’s

Melaleuca Bico vex Mo itori g

Qualitative assessment of Melaleuca biconvexamonitoring data is also undertaken looking for hanges in retained and translo ated stands of Melaleuca biconvexa, in luding redu tion in or impa ts to suitable habitat. A range of monitored parameters will be olle ted to inform hanges to ondition of retained and translo ated Melaleuca biconvexa. These in lude:

• Area of stands; • Height and DBH of selected individuals; • Plant health / dieback; • Leaves yellowing; and • Evidence of yrtle rust.

Additional details on the data olle ted and the timing of Melaleuca biconvexa monitoring are detailed in the CMP.

Maho y’s Toadlet a d Wallum Froglet Mo itori g

Qualitative assessment of frog monitoring data is also undertaken looking for hanges in frog habitat, in luding redu tion in or impa ts to suitable habitat (note that these ould likely be the same measurements as for other vegetation monitoring). Data olle ted will be ompared to baseline and previous years to allow analysis of temporal hanges. The report will:

• Describe any spatial and te poral changes in the distribution and abundance of Mahony’s Toadlet and Wallu Froglet;



• Describe any spatial and te poral changes in the distribution, abundance and co position of plant co unities;

• Describe the condition of a phibian populations in exclusion zones; • Describe the condition of plants co unities in exclusion zones; • Outline any changes to Mahony’s Toadlet and Wallu Froglet habitat that ay have resulted fro project related i pacts;

• If any i pacts have occurred, describe what itigation easures were used to itigate the i pact;

• Outline any adaptive onitoring or additional onitoring protocols developed as a consequence of annual onitoring; and

• Provide reco endations (where necessary) for updating this CMP based on the outco e of annual onitoring.

Further details on the data olle ted and the timing of vegetation monitoring are detailed in the Conservation Management Plan for Mahony’s Toadlet and Wallum Froglet.

GDE management a tions, triggers, mitigations and ontingen ies are presented in Se tion 9.



5 Moni oring Program

5.1 I troductio

This se tion outlines the intended groundwater monitoring program, lo ations, frequen y and data requirements.

5.2 Pre-Co structio Mo itori g

5.2.1 Co cept Desig Stage

Con ept design monitoring was undertaken as part of the geote hni al field investigations undertaken by Coffey (2016). Ten open standpipe piezometers were installed, four in January 2016 and an additional six in June 2016. Fortnightly water level monitoring was undertaken from June to September 2016.

Four groundwater samples were olle ted and analysed for Chloride, Condu tivity, pH and Sulphate during this period for durability purposes.

5.2.2 Pre-Co structio Detailed Desig Stage

Existing piezometers are to be monitored throughout the detailed design and onstru tion phase until the piezometers are de ommissioned as required by the onstru tion programme.

5.3 Lo g Term Mo itori g Locatio s

New long term monitoring bores are to be installed up and down gradient from the site. Lo ations are shown in Figure A-2.

Groundwater monitoring lo ations have been hosen to allow assessment of proje t impa ts to groundwater. Monitoring bores shall be lo ated upgradient, within-site and down gradient within site onstraints.

There are six groundwater monitoring bores to be installed within the proje t boundary. These bores are lo ated outside the onstru tion foot print and will be used for pre, onstru tion and operational monitoring purposes. The groundwater monitoring bore lo ations are indi ated on Figure A-2 and the details provided in Table 5-1. The lo ation of long term monitoring bores have taken into a ount the lo al and regional hydrogeologi al setting (Se tion 3) and proje t onstru tion onstraints. The monitoring bores are all installed in the shallow alluvial/ highly weathered residual material of the un onfined aquifer.

Table 5-1: Groundwater onitoring bore details

Total Scree

ID

P101

Easti g

Northi g

RL TOC (mAHD)

13.13

Depth from TOC

(m)

9

Scree Le gth (m)

3

i terval (mbTOC)

(m to m)

4.7 - 9

Notes / Justificatio

Up Gradient Monitoring

P102

P103

12.35

14.94

7.3

8.8

3

3

3.5-7.3

4.8-8.8

Site Monitoring

Up Gradient Monitoring

Existing

BH01_P 11.46 7 6 1–7 Piezometer - Adopt

as long term up gradient monitoring



Total Screen

ID Easting Northing RL TOC (mAHD)

Depth from TOC (m)

Screen Length

(m)

interval (mbTOC) (m to m)

Notes / Justification

BH03_P 11.17 8 6 2–8 Existing

Piezometer - To be decommissioned

BH05_P 10.68 5.9 3 2.9–5.9 Existing


BH10_P 13.7 10 3 7–10 Existing


BH11_P 13.34 3 2 1–3 Existing


BH12_P 13.34 8 3 5–8 Existing


BH16_P 11.41 7 3 4–7 as

Existing Piezometer - Adopt

long term down gradient monitoring

BH19_P 9.95 6 3 3–6 as


long term down gradient monitoring

BH30_P 12.41 4 3 1–4 Existing


10.2 7 3 4–7 as


BH37_P long term down

gradient monitoring

5.4 Monitoring Frequency & Reporting Requirements

The reporting requirements under this management plan are listed in Table 5-2. Reporting will be undertaken quarterly, unless additional reporting is triggered by exceedances of the trigger values or contamination. Monitoring reports will be provided at 12 monthly intervals from the start of construction. Water level measurements will be recorded continuously in the monitoring bores with the use of electronic data pressure transducer loggers and manual measurements and retrieval of data will be undertaken at the frequency indicated in Table 6.

Operational reporting requirements will be determined once the construction reporting has been completed.



Table 5-2: Monitoring frequency and require ents

Freque cy

Ma ual

Water Level (1)

Water

Quality

A alysis

GDE

Ecologist

Survey

Reporti g Comme t

Preco structio

Monthly X X

3 rounds of Pre onstru tion monitoring

(in addition to 2016 results)

Prior to dewatering

X Supplementary baselin

New Intercity Fleet Maintenance Facility …...Dewatering to install the track subsurface drainage is expected to have a minor, short term impact onthelocalwatertable levelduring construction,

Documents