Providing Sewage Infrastructure to Construction Accommodation and LNG Facilities on Curtis Island – Key Challenges and Lessons Learned

1 Abstract The Curtis Island Water and Sewerage Infrastructure Project includes the construction of sewage infrastructure between the Gladstone mainland STP and Curtis Island to support proponents developing liquefied natural gas (LNG) facilities on Curtis Island. Gladstone Area Water Board (GAWB) and Gladstone Regional Council (GRC) commissioned GHD to design and superintend the works. The sewage infrastructure is owned and operated as part of GRC’s sewerage network. The provision of sewage infrastructure, connecting the island to the mainland, eliminates the need for barging and permanent self-contained sewerage solutions for each LNG proponent and reduces the overall impact of potential discharges from these facilities into Gladstone Harbour, which is located within the Great Barrier Reef World Heritage Area and adjacent to the unique Great Barrier Reef The sewerage elements of the project comprised the following: Three sewage pump stations 18 km of HDPE Pipeline up to OD250 HV power generation and reticulation Control and telemetry infrastructure to facilitate operation from the mainland A 6 km access road and associated drainage structures 2.1 km crossing of Gladstone Harbour comprises 2 x 250 OD HDPE pipelines with steel envelopers constructed utilising Horizontal Directional Drilling (HDD) The project also included water infrastructure which is owned and operated by the Gladstone Area Water Board which are not described here. The project addressed the needs of various stakeholders, including GRC, Gladstone Area Water Board, four LNG proponents, the Gladstone Port Corporation and various regulatory agencies. The project was successfully implemented within a compressed timeframe to meet the service requirements of the LNG proponents. The project overcame significant physical challenges including remoteness of the island site, lack of existing infrastructure, constrained construction corridor and difficult topography. The project also addressed the challenges of operating and maintaining infrastructure isolated from the mainland. The crossing of Gladstone Harbour was one of the longest and deepest HDD installations utilising HDPE completed in Australia. The HDD employed a number of innovative techniques never before successfully used in Australia.

GLNG PLANT

INFRASTRUCTURE CORRIDOR SPS L1 SITE OFFICE & MATERIAL LAYDOWN

HDD SITE

Figure 1 Construction footprint southern Curtis Island

Common Water and Sewerage Infrastructure 2 Background Prior to the LNG construction, there was little or no The Queensland Coordinator-General’s evaluation of Environmental Impact Statements (EIS’s) for development on the island. As LNG facility Gladstone LNG (GLNG), Queensland Curtis LNG construction was ongoing prior to this project, initially (QCLNG) and Australia Pacific LNG (APLNG) all the construction water and sewage was contained a requirement to review the feasibility of transported by ferry to and from the island. The provision of piped infrastructure connecting the island co-locating water and sewage services. Gladstone to the mainland eliminates the need for temporary Area Water Board (GAWB) is responsible for bulk water supplies for domestic and industrial use in the barging and permanent self-contained water and Gladstone region. Gladstone Regional Council (GRC) sewerage solutions for each LNG proponent. It also is responsible for the provision of sewerage services. reduces the overall impact of potential discharges GAWB and GRC jointly commissioned Concept from these facilities into Gladstone harbour. Studies for the provision of piped water and sewerage infrastructure. Financial support for these 3 The Need for the Project studies was initially provided by APLNG who, while investigating alternatives to barging and onsite Queensland has significant coal seam gas reserves. treatment, were also interested in alternative To enable the gas to be safely stored and transported solutions for the provision of high water volume and it must first be cooled to the point that it becomes flow rates for pressure vessel testing and liquid natural gas (LNG). commissioning. At the time of the project, three LNG processing and Based upon these studies, GAWB and GRC entered export facilities projects were under construction with into a Common Use Infrastructure Agreement (CUIA) a forth pending final investment decisions. The LNG with APLNG under which they agreed to construct Proponents and respective owners were: infrastructure to serve their LNG facility on Curtis Australia Pacific LNG (APLNG) - a joint Island. At this time other LNG proponents were venture project between Origin, progressing stand-alone infrastructure solutions due ConocoPhillips and Sinopec to the perceived technical difficulties with this project Gladstone LNG (GLNG) - a joint venture and likely timescale required for obtaining approvals, between Santos Ltd, Petronas, Kogas and procurement and construction periods. Total The water and sewerage services were required in Queensland Curtis LNG (QCLNG) - owned two phases: by the Queensland Gas Company QGC (a BG group company) Phase 1 Flows – to meet immediate sewerage Arrow LNG- a joint venture between Shell demands (and eliminate the requirement for and PetroChina now withdrawn from barging of these services across Gladstone constructing a LNG plant on the island. Harbour). Initial milestone dates were set at August 2011 and later amended to May 2012 For each LNG facility, it was estimated that a peak Phase 2 Flows – to meet commissioning construction phase workforce in excess of 2,000 requirements for high water volumes and flow workers would be required. A large proportion of this rates. Initial milestone dates were set at workforce would be resident on the island, housed in January 2012 and later amended August to temporary construction camps. There was a need for 2012. sewerage and water infrastructure to serve construction phase demands (both domestic and The CUIA was structured to allow the other LNG construction related) and longer term operational proponents to accede to it, which they did at a later demands. date. Prior to the concept of providing a sewerage services to the island via pressure mains constructed using Horizontal Directional Drill (HDD) methodology, each 4 Remote Location and Logistics of the individual LNG proponents planned to provide The sewage infrastructure alignment extends across their own self-contained sewage solutions using three main areas: individual sewage treatment plants. Treated sewage 1. Australian Mainland: Located on the RG effluent that was surplus to on-site irrigation needs Tanna Coal Terminal and a Fly Ash Disposal would be discharged to Port Curtis. Area utilised by NRG Power. This infrastructure includes the pipeline discharging to the Gladstone Sewage Treatment Plant.

2. Crossing of Gladstone Harbour: The pipeline was installed using HDD. 3. Curtis Island: The majority of the sewage infrastructure is located on the island, including; three pump stations, power generation systems and sewer connections to the LNG proponents. This alignment is illustrated in Figure 2

Figure 3 Pipeline installation in GPC & NRG haul road

The crossing of Gladstone Harbour was located to provide the shortest route possible; from RG Tanna Coal Terminal to Hamilton Point on the southern end of Curtis Island. On Curtis Island, the sewage infrastructure corridor ran north-south, primarily through a parcel of land owned by the coordinator general. The land was designated as a service corridor and shared with gas proponents for gas trunk pipelines. One of the key project challenges was the 30m corridor available for sewage infrastructure which was primarily located on the side of a ridge with relatively steep cross slopes (up to 24% in some locations). The benching of the cross slopes for the access track coupled with erosion and sediment infrastructure, resulted in a very constrained construction area. The isolation from the mainland presented significant logistical challenges. The project utilised a single barge for most of the project to transfer all equipment and vehicles from the Gladstone Marina to Curtis Island, as illustrated in Figure 4. Multiple contractors Figure 2 Location of sewerage infrastructure utilised this barge and coordination was achieved by the appointment of a single barge master to handle all scheduling. On the mainland, the route selection for the infrastructure was coordinated with numerous stakeholders including the Gladstone Ports Corporation (GPC) and NRG Power, as the pipeline crosses operational facilities of these organisations. The pipeline was generally constructed in a haul road utilised by GPC and NRG. Construction was staged to ensure this supply route was not affected by pipeline installation.

Figure 4 Barge landing on Curtis Island

5 Parallel Approvals and Design island. Of the three pipelines two DN 250 PN25 HDPE pipelines are used for sewerage in a duty To meet the LNG Proponent’s water and sewerage standby arrangement. delivery dates, the approvals had to be undertaken at the same time as detailed design. Given the large linear footprint and the location of the project, this project triggered a large number of approvals including:

Commonwealth CURTIS ISLAND Referral to the Federal Minister Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) Queensland (State) Operational Works permit for earthworks and construction within Gladstone Ports Corporation land

Development Approval, Material Change of Use, assessed by the Co-ordinator General Figure 5 Mainland HDD site and alignment Resource Entitlements from the Department of Infrastructure and Planning and the Department of Environment and Resource The water and sewerage services were required to Management meet immediate sewerage demands from the Tidal Works Permit under the Sustainable construction camps and eliminate the requirement for Planning Act 2009 (SPA) for works carried barging of these services across Gladstone Harbour. out in, on or above land under tidal water The amended milestone date for the operation of the sewerage pipeline was May 2012. Clearing of Native Vegetation permit for

clearing native remnant Regional Concept designs for the crossings were completed in Ecosystems on Curtis Island under late 2010. Following an accelerated design, Vegetation Management Act 1999. approvals and tender process, a contract was let for Protected Species Clearing permit required the pipeline crossings in September 2011. The under the Nature Conservation Act 1992 (NC contract was let to Coe Drilling from Queensland who Act) and Nature Conservation (Protected had formed a joint venture with Mears Directional Plants) Plan 2000 for the clearing of any Drilling from the United States. wildlife, including prescribed plants, and

offset agreements. The drilling contractor completed the crossings within Clearing of Marine Plants as defined under a compressed timeframes. It was one of the longest the Fisheries Act 1994 as plants located and deepest HDD installations of its type in Australia within or adjacent to tidal land. at the time. Cultural Heritage Indigenous Cultural Heritage: Cultural Heritage Management Plan (CHMP) to comply under the ACH Act Challenges with obtaining approvals included their preparation and submission in advance of the works being fully detailed and ensuring that any constraints were included within the contractual terms for the tenders. This was achieved by a proactive approach, keeping relevant parties updated and informed at all stages, and close monitoring of progress. The team benefitted from a number of dedicated individuals with established contracts within the major agencies.

6 Crossing Gladstone Harbour Figure 6 Drill rig on the mainland The success of this project hinged on the three 2.1km parallel horizontal directional drills (HDD) to construct The project used value driven processes that resulted critical pipelines between the mainland and the in innovative approaches and solutions to achieve a 4 number of milestones for HDD technology in pipes provided permanent sewerage services and Australia: interim construction water. The crossing length of 2150m and 74m deep A number of pipe materials were considered for the beneath Gladstone Harbour is one of the HDD, including fusible PVC. However the predicted longest of its type in Australia, requiring the tensile stresses during installation precluded this use of steel enveloper pipes to reduce the material without an envelope pipe. risk of overstressing the HDPE product pipe One of the challenges was the limited geotechnical during installation. information which was due to approvals timeframes Harbour crossings were completed using two and initial funding issues. That precluded of the largest HDD drilling rigs (500 ton) comprehensive overwater drilling investigations. This available in Australia. was mitigated by a bespoke commercial framework The risk of drilling fluid losses into the including contractor incentivisation with a mix of time sensitive harbour environment was mitigated and fixed cost payments to proportion risk equitably. by the contractor’s choice of intersect drilling (drilling from both sides and meeting in the Another challenge was the accelerated construction middle) – the first successful use of this to meet the agreed operational date. This was approach in Australia. achieved by adopting new tooling consisting of An Optical Gyroscope was used for the first lockout swivel which allowed the drill rigs at both the time in Australia to undertake the complex ends of the drill string to assist with reaming of the down hole steering operation, which enabled pilot hole. parallel installations only 4 m apart at Communicating the project drivers resulted in a entry/exit and the successful use of the shared, collective vision which encouraged the teams intersect technology. to work together to seek solutions. Close client involvement in the risk management and decision making process assisted in the successful delivery of the HDD project.

Figure 8 Installation of the steel enveloper

7 Hydraulics The concept stage of the project explored various route selection options to determine the optimum alignment. However, the project was relatively constrained by the service corridor available. The topography of the project alignment can be characterised as follows:

A relatively flat section, at low elevation on Figure 7 HDD drilling head the mainland The HDD crossing under the Gladstone Harbour at a maximum depth of -70 m AHD The first pilot hole and intersect was successfully Highly variable topography across Curtis completed in December 2011 and was followed by Island; both in terms of elevation and the installation of steel envelopers and two DN 250 gradient PN25 HDPE product pipes by May 2012. These

This topography presented a number of challenges These design flow rates were primarily sized to cater for the hydraulic design. The system design was for peak LNG construction loading. When the LNG governed by the following key hydraulic facilities transition to operational phase, the demands considerations: will drop significantly. In sizing the infrastructure a balance was achieved in order to cater for the short Ensuring significant velocity within the term peak construction demands whilst ensuring that sewage pipeline to prevent settlement of the system was not oversized after the transition to solids and movement of air. operational demands. This oversizing could have Ensuring sewage pipelines did not drain on generated significant problems with regards to pump shut-off as a result of the variable sewage age and septicity. topography. This would cause potential pump damage, low pipeline velocities and The hydraulic grade line for the system is indicated in unfavorable transient conditions. Figure 9. Ensuring predictable hydraulic conditions for the pumps to prevent damage from cavitation. Providing a relatively simple and conventional sewage pump station arrangement. The use of booster pumps, control valves or non-conventional high pressure transfer pumps was not preferred due to the operation and maintenance challenges as a result of the isolation from the mainland. Minimising elevation change and therefore lift requirements of the pump stations. Long length of rising main between the island and STP. Figure 9 Hydraulic grade line Allowance for LNG Proponents to discharge flows independently into the operating sewerage system. Informed by these considerations, a solution utilising three pump stations was developed. The sewage is transferred for almost the entire alignment via pressurised rising main. The system configuration includes the following: Pump Station L3 which collects flow from APLNG and QGC; Pump Station L2 which collects flow from PS1 and Arrow; and Pump Station L1 which collects flow from PS3 and GPCL and discharges to the Gladstone STP. Maximum Demands from each proponent are summarised in Table 1.

Table 1 LNG Proponent Design Flows Proponent Maximum Design Flow Figure 10 Installation of the submersible pump (Litres/second) APLNG 11 The 2.1 km HDD crossing reaches a depth of -70 m QGC 10 AHD and provides no air or scour outlets across this distance. This is highly unusual for a pressurised Arrow 10 sewage rising main. The hydraulic design GPC 6 considered: GLNG 1.4 Potential for solids settling in the bottom of the HDD restricting the pipe

Potential for air pockets becoming trapped in allows for the connection of reticluated mains power the pipe as a result of local high and low in the future. points caused by variances in the HDD Power from the generators which are located at the steering. central pumpstation (L2) is reticulated to the two To counter these issues, a relatively high velocity is other sewage pump stations through the pumped through the HDD in combination with underground HV network. The location of the infrastructure to facilitate regular pigging of the main. generators was selected to allow ease of An air movement study was performed on the main to mainatance, refueling and operational flexability. mitigate the potential for air pockets to become The generators are fueled from a double walled trapped, equations given by Escarmeia (2007) where 20,000L deiesel stoarge, whis has 10 days supply. A utilised for this study. fuel tanker is barged to the isalnd weekly which refuels the diesal storage tank. 8 Septicity The sewage produced by the LNG facilities is primarily domestic waste. From the furthest LNG plant, sewage may be pumped for up to 13 km. The hydraulic design ensured that velocity in the main remained high and working storage was minimised in order to reduce the sewage age reaching the Gladstone STP. However, a residual risk remained of odour and corrosion caused by septicity of the sewage. Due to the isolation of the infrastructure alignment, there is a significant buffer from any sensitive receptors. Consequently a ‘wait and see’ approach was adopted for odour nuisance. Connectivity was provided for at every air valve to retrofit odour scrubbing equipment in the future if odour is detected by nearby receptors. The pump wells, collection wells Figure 11 Diesel storage for generators and emergency storages were fitted with odour scrubbers to minimise odours for operation staff during their weekly inspections. 9.2 Communication and Control Due to the risk of corrosion, primarily from Hydrogen Normal operation and monitoring of the overall Sulphide (H2S), the following materials were utilised: system is be done remotely via a PLC and RTU based SCADA system. The island power generation HDPE for all rising mains plant is controlled by a master PLC. The Master PLC Ductile iron pipe with Calcium Aluminate also controls the operation and switching of the island Cement Lining or FBE coating for pump substations. discharge pipework Epoxy coating of internal surfaces of All four substations communicate via point to manholes multipoint radio communication network through HDPE liner (Anchor Knob Sheet) on internal GRC’s Curtis Island Communications Hut, on their surfaces of pump station wet wells and own dedicated channel. The SCADA and Sewerage emergency storage chambers Pump Stations communicate on the other stream on the same channel as the HV system. This allows GRC’s control center to monitor and 9 Power, Communications and remotely control specific components of the Island Control power network and sewerage pumping stations.

9.1 Power 10 Access Track The Curtis Island Power Generation System is a A 6.6km access track was required on the island to semi-automated power generation system that provide access for weekly inspections to the consists of two (duty / stand-by) 800 kVA prime rated sewerage and water infrastructure as well as the diesel engine generators, transformers which transportation of diesel to generators located at stepped up from 415V from the generators to 11 kV sewage pumping station L2. and 5.5km of 11KVA distribution network. The system was desinged for remaote operation and also

Given the topography, it was not possible to comply with Austroads’ sight distance requirements along the entire length of the track. However, Austroads’ standards are generally intended for sealed public access roads with speeds in excess of 50 km/h. The sight distances achieved for the track were deemed suitable. The design also incorporated the use of signage and passing bays to assist in the safe travel of vehicles along the track.

Pavement Design The fast track nature of the project and restrictions in vegetation clearing during the design phase resulted in the designer assuming a number of CBR values and designing pavements to suit. During pipeline Figure 12 Construction of the access track construction it was found that the majority of subgrade CBRs were greater than 10%, (which was previous adopted for the subgrade in the pavement design). In the isolated sections where the CBRs where less than 10%, 125mm of compacted select fill was required below the base course in addition to the sub-grade treatment.

Review of Locally Source Materials Material property investigations were undertaken to assess stockpiled material which was excavated during site levelling of pumping station L3. The investigation focused on the suitability for access track pavement material in an attempt to reduce the costs associated with importing approximately 100,000 tonnes of pavement materials from the mainland. The CBR results from the stockpiled material were Figure 13 Access track guard rails either of culverts less than the minimum CBR requirements for the various pavement layers. Furthermore, the Plasticity Index of these materials was typically higher than the Access was designed to accommodate maximum specified. The risks associated with using approximately two heavy vehicles per week over a these materials were mainly related to inadequate ten year design period. Design Equivalent Standard shear strength when the road is being trafficked Axles was calculated in accordance with the during wet conditions. This would result in potential Transport and Main Roads Road Planning and pavement deformation and/ or failures, requiring Design Manual. The pavement design was based on increased maintenance/repair during the design life Austroads Guide to Pavement Technology Part 6: of the pavement. Based on the material Unsealed Pavements. investigations, it did not appear that the stockpiled materials were suitable for use in the wearing or base The location of the access track was horizontally course when assessed against conventional material constrained to the 30m wide pipeline corridor, which requirements for unsealed roads. had very challenging topography with often steep gradients along the track. Given that the access track will be primarily used for maintenance of Pavement Thickness Design infrastructure and not accessible to the public, a It is standard practice in Australia to adopt a separate maximum design speed of 30 km/h was adopted. wearing and base course configuration. However, The maximum longitudinal gradient for the track was given the location of the project and the logistics generally adopted as 16%. However, given the local involved with importing materials to the island, a topography and restrictions in horizontal alignment combined wearing course and base of 200mm for the track, there were a number of instances where (excluding construction tolerances), constructed in steeper grades were adopted over relatively short two passes was adopted. The material properties of distances (all less than 50m). combined wearing and base course were specifically

8 tailored to the project with a maximum Plasticity accommodated with twin DN1800 or areas dictated Index of 8 and a CBR of 50%. by downstream drainage conditions. The causeway geometry was determined so that during a 1 in 20 Drainage ARI, the flows across the causeway would not exceed the maximum depth and velocity required for Drainage design is critical to the integrity and safe crossing in a 4WD vehicle. performance of the access track. The culverts, diversion banks, and v-drains along the access track were designed to convey a 20 year Average Recurrence Interval (ARI) design storm event. The hydrology and hydraulic software package DRAINS (Version 2011) for steady state flow was used for both the hydrologic and hydraulic design of the drainage network. A standard diversion drain and berm was adopted for diverting the upper catchment stormwater flows away from the road drainage channels. Given the v-drains are only conveying local stormwater from the access track, the standard design was deemed adequate for the majority of the road. However in some sections additional capacity was required and table drains were adopted in these Figure 15 Typical causeway with scour protection locations.

Scour Protection Culverts and Headwalls Scour protection downstream of each culvert were Standardised circular Class 4 reinforced concrete specified with minimum rock sizes and length of rock. culverts of size DN 900 and DN 1800 were adopted Drop rock scour protection was adopted for sections throughout the design. In some case twin DN 1800 of diversion drains and access track drains the where culverts were adopted to convey the design flows. channel velocities exceed 2 m/s. In situ reinforced concrete headwalls were constructed around the upstream and downstream ends of the culvert to provide four functions: anchor 11 Operations and Maintenance the flush joint culverts, retain and protect the track One of key requirements of the project was to ensure embankment, protect the pipeline trench from scour, that the operation and maintenance of the system and increase the efficiency of culverts. The structures was as minimal as possible. This is primarily due to were designed to take into account the remote nature the difficulty in mobilising to Curtis Island in the event of the site and difficulty of future maintenance. of an emergency. The HDD was assessed as a significant risk in the event of a failure underneath Gladstone Harbour. Comprehensive quality control was implemented during construction, however there remained a residual risk to the system if the HDPE pipe under Gladstone Harbour failed. Due to the use of a steel enveloper there remains a possibility that the HDPE pipe could be removed and replaced, however there would be a significant delay in mobilising an appropriate rig and equipment to site. These risks were mitigated by installing a ‘spare’ HDD crossing. There are three pipes that have been installed using HDD under Gladstone Harbour: one water, one sewer and one ‘spare’. In the event of a failure of either the water or the sewer, a cross connection has Figure 14 Culvert headwall construction been installed to allow either system to switch over to the spare. In the early phase of the project, the Causeways ‘spare’ was used to convey construction water until Reinforced concrete causeways were constructed in the larger water pipe was installed. certain locations where the design flow could not be

There is approximately 13 km of HDPE sewer rising main installed using conventional trenching on Curtis 12 Lessons Learned Island and the Mainland. The project developed a repair strategy in the event of a pipe failure during operation. HDPE is relatively challenging to repair The key lessons learned from this challenging project compared to other pipeline materials. Following a included: review of the fittings on the market, the project Delivering large projects under extremely developed a repair strategy using mechanical compressed timeframes requires a proactive couplers to create a robust procedure to ensure the and collaborative approach from both the integrity of the repair, whilst addressing issues such designers and the client to successfully as thermal movement, wall stress and material deliver the project. integrity. Electrofusion welding technologies do not Communicating the project drivers resulted in form part of the emergency repair strategies as they a shared, collective vision which encouraged were evaluated as being more complex with a lower the teams to work together to seek solutions. probability of achieving a successful repair. Approvals are often on the critical path and can be undertake in parallel with design and Emergency Storage tanks were provided at each procurement, by adopting: a proactive pump station to provide a volume of storage in the approach, keeping relevant parties updated event of a system fault. This was important both due and informed at all stages, and close to the mobilisation time to rectify the fault and the monitoring of progress. environmental implications of sewage overflow. Adopting new construction technologies such There is a total of 390 kL of storage between the as lockout swivel for the HDD can reduce three pump stations. This volume was provided using risks and accelerate construction. below ground DN3000 precast concrete pipes, Key operational risks were identification and providing between 6 and 12 hours of storage prior to mitigated in early design. This included the overflow to the environment at operational flows. installation of spare pipeline across the harbour. Construction and operation of pipeline in remote areas are important considerations when selecting the pipe material and jointing methodology. Keeping the hydraulics simple provides operational flexibility.

Figure 16 Emergency storage construction

A leakage monitoring system was provided, utilising flowmeters at upstream and downstream ends of the pipelines. Pigging launch and receival infrastructure was provided to scour the pipelines and avoid the build-up of sludge in order to maintain internal diameters and avoid blockages. This was particularly important to mitigate the risk of blockage or solids settlement in the HDD crossing.

References: Escarameia M (2007). Investigating Hydraulic removal of air from water pipelines. Water Management 160 (Issue WMI) 25-34

The Authors:

Hugh McDonald Senior Civil Engineer – GHD P: 07 3316 3479. E: [email protected] Hugh is a Senior Civil Engineer with 10 years experience on a wide range of water and wastewater projects. Hugh was design manager on the Curtis Island Water and Sewerage Project.

Ben Hoiberg Water Engineer – GHD P: 07 3316 4488. E: [email protected] Ben is a Civil Engineer with GHD’s Water Process and Systems Group. Ben was a design and site engineer for GHD on the Curtis Island Water and Sewerage Project.

Chris Donnelly Principal Project Manager - GHD GHD - P: 07 3316 3235. E: [email protected] Chris is a Principal Project Manager at GHD with over 25 years experience in water and civil projects. Chris was project director for GHD on the Curtis Island Water and Sewerage Infrastructure Project.