Kemps Creek wastewater pressure main, Sydney, Australia

NEC has been used to deliver a vital wastewater pressure main in the Kemps Creek suburb of Sydney, Australia. Client Sydney Water awarded the project to Quickway Constructions Pty Ltd in April 2024 under an AU$80 million (£40 million) NEC4 Engineering and Construction Contract (ECC) Option A (priced contract with activity schedule). 

Construction started in July 2024 and the scheme was completed under budget and three months ahead of approved programme in June 2025 – a performance strongly aligned with the NEC ethos of proactive management, collaboration and clarity of obligations. 

The contract involved building 6.8 km of dual 0.6 m diameter wastewater pressure mains from a sewage pumping station in Gurner Avenue, Austral to the new Upper South Creek advanced water recycling centre (AWRC), which on completion in July 2026 will produce recycled water, renewable energy and bioresources. Together with the AWRC, the pressure main will support population growth in New South Wales’ South West Growth Area, which is set to increase from 2,300 homes in 2022 to around 38,000 by 2056. 

Over 5 km of 20 bar polyethylene pipes were laid in three open-trench sections while horizontal directional drilling was used to install an 852 m section under the Kemps Creek nature reserve. Two micro-tunnelling sections totalling 615 m were also installed, from Exeter Road to Pratten Street and across Elizabeth Drive, using polyethylene-lined steel pipes encased with 1.04 m diameter reinforced concrete, to minimise impact on the environment and communities. 

Sydney Water was the NEC project manager. Designer WSP was initially engaged under an NEC4 Professional Service Contract (PSC) prior to novation to the ECC contractor, a deliberate strategy to balance early design progression with later clarity of risk transfer.

Experienced user

Sydney Water is now an experienced user of NEC4 contracts, have first adopted them in 2019 for its 2020–2030 construction works and service frameworks, which are worth up to AU$4 billion (£2 billion). In 2021 it began using NEC4 for major projects too, starting with the AU$280 million (£140 million) ProMac water supply upgrade, which was completed in 2025. 

Senior commercial manager Surabhi Kashyap says Sydney Water has developed a tailored template for each NEC4 ECC contract option. ‘For this project, NEC4 ECC Option A was selected due to the relative simplicity of the scope both in terms of site constraints and construction methodology.’

She says the most significant risk for the project was meeting the AWRC commissioning flow requirement within the specified timeframe. ‘To mitigate this, we progressed with design development under a separate NEC4 PSC contract. This approach allowed design and procurement activities to run in parallel, easing pressure on the procurement team during the expression of interest and selective tender process.’ 

Kashyap says since the design was developed to 80% before novating it to the winning bidder, this provided scope clarity and enabled contractors to offer more competitive pricing. ‘Furthermore, design risks were transferred to the delivery contractor through the deed of novation in accordance with NEC4 principles of clearly allocated responsibilities and well-defined scope. The novation process was used not just as an administrative step but as a risk-management tool, ensuring that design liability, interfaces and residual risks sat unambiguously with the party best placed to manage them.’

She adds that option X5 on selective completion was also introduced – a first for Sydney Water – along with option X7 on delay damages to ensure the AWRC commissioning flow requirement date was met. ‘However, any scope independent of flow requirements was excluded from delay damages. This maintained a fair balance between the contractor’s risk exposure and associated costs and ensured that X7 incentivised the correct outcome rather than creating disproportionate risk premiums.’

Collaborative working

Senior project manager Layla Hosseini says it was the contractor’s first NEC project. ‘To support collaboration and build the contractor’s understanding of NEC principles, we provided the contractor’s team with a full-day training session. Together with a co-located project team and regular NEC meetings, this fostered a collaborative working environment with transparency and open communication between all parties.’

She says the NEC early warning mechanism promoted proactive issue identification and resolution, helping to mitigate risks and avoid delays. ‘The commercial team ensured early warning meetings focused on solutions and mitigation plans, discouraging commercial negotiations to uphold early warning principles and the contractual requirement for “mutual trust and co-operation”.’

Hosseini says the NEC programme management principles also helped to manage changes on the project. ‘NEC compensation events were managed efficiently and fairly through clear procedures, supporting timely agreement and cost control. This avoided unnecessary commercial tension and ensured that compensation event pricing reflected true impact, not positional bargaining.’

One-team culture

She concludes, ‘The Kemps Creek project redefines how major infrastructure can be delivered – three months ahead of schedule, significant savings against the approved budget and with community and environment at its heart. The NEC4 collaborative contract gave us the framework, but it was our culture that made it work.

‘Following NEC principles, we built a one-team culture based on trust, shared accountability and proactive problem-solving. Diversity and inclusion were central to our approach, with strong female representation across leadership and engineering roles driving innovation and balanced decision making. 

‘The novation of the PSC design into the ECC contract reinforced this integrated team structure, enabling a seamless transition from design development to construction execution without the fragmentation often seen under traditional procurement models.’

Benefits of using NEC

• NEC4 ECC Option A was considered the most appropriate procurement route due to the relative simplicity of the scope both in terms of site constraints and construction methodology.
• NEC option X5 on selective completion and option X7 on delay damages helped to ensure the commissioning flow requirement date was met.
• NEC early warning mechanism promoted proactive issue identification and resolution, helping to mitigate risks and avoid delays.
• NEC compensation events were managed efficiently and fairly through clear procedures, supporting timely agreement and cost control.
• Early designer engagement via NEC4 PSC and later usage of the novation mechanism ensured design maturity and clearer risk transfer.
• The project was completed under budget and three months early.