Bonnycraig Water Treatment Works, Peebles, Scotland

NEC has been used to procure a new £31 million modular treatment works at Peebles in Scotland. NEC Users’ Group gold member Scottish Water let six separate NEC contracts for the 4 Ml/day plant, which is only the second in the UK to use state-of-the-art ceramic membrane filters.

Mechanical, electrical, instrumentation, control and automation (MEICA) contractor Ross-shire Engineering was engaged in August 2019 under an NEC3 Engineering and Construction Contract (ECC) Option C (target contract with activity schedule) for the process design stage, and Option A (priced contract with activity schedule) for plant manufacture, construction and commissioning. Civil engineering contractor Amey was then engaged in January 2021 under ECC Option E (cost-reimbursable contract) for the civil engineering design stage and Option C for construction. Client designer Mott MacDonald and NEC project manager Turner and Townsend were each appointed under an NEC3 Professional Service Short Contract (PSSC).

The project involved replacing a life-expired 1970s treatment plant with a more compact and energy-efficient design featuring four ceramic membrane filters. It was built offsite by the MEICA contractor’s Muir of Ord factory in the Highlands, over 360 km away, and delivered and installed in 17 sections weighing up to 36 t – saving around 18 months compared to traditional on-site construction. Greenhouse gas emissions were further reduced by installing 288 rooftop solar panels, electric vehicle charging points and reusing the spoil on site to help reduce vehicle movements and screen the plant.

The works were completed to the agreed contract schedules and budgets and the plant was successfully commissioned in April 2023.

Experienced client

Scottish Water is an experienced user of NEC contracts, with recent examples including the challenging Lochmaddy water treatment works in the Outer Hebrides and the 42 km long Katrine Aqueducts refurbishment near Glasgow. Senior project manager John Shaw says, ‘The NEC requirement to work in a “spirit of mutual trust and co-operation” helps ensure that our project teams work collaboratively to deliver the best possible outcomes for our customers.’

He says the design phase of the Peebles project was mostly undertaken during the Covid-19 lockdowns in 2020. ‘This highlighted the power of NEC-inspired collaboration and communication between project team members. Incorporating new technologies into modular solutions was not easy, especially during lockdowns, but the outcome was highly satisfying.’

Shaw says NEC also provided a range of appropriate procurement options to engage with its tier 1 contractors. ‘On this project we used a mix of ECC Option C and E for our MEICA and civil contractors respectively in the early contractor involvement phase. We then moved to ECC Options A and C for the construction work, where the risks were more clearly defined.’

Managing change

He says there were still a number of changes required during construction. ‘Thanks in part to NEC there was a strong relationship between the parties, and we all used the NEC contract processes to manage the works changes as effectively as possible.’

Shaw says use of NEC early warnings and regular risk-reduction meetings were the key to ensuring a successful outcome. ‘These collaborative processes helped us jointly manage project risks and issues. While there were some disagreements on compensation event valuations, the NEC requirement for clear communications and constructive dialogue ensured that solutions were found to keep the project on track.’

He says the CCM online contract management system was used across the project. ‘In line with the NEC ethos, the system provided complete transparency on project-related issues and ensured that project team members were working from one source of truth. Overall everything was well managed and processed effectively.’

On successful completion of the project, director of capital investment Mark Dickson said, ‘We are delighted to have finished the new water treatment works in Peebles. The team have done a fantastic job in building a modern works which uses lower carbon construction techniques while reducing the amount of disruption caused by the work.’

Benefits of using NEC

• NEC requirement to act in a ‘spirit of mutual trust and co-operation’ helped to ensure the civil and MEICA contractors worked collaboratively, particularly during the Covid-19 lockdowns.

• NEC provided appropriate procurement options for the various phases of innovative project, ranging from cost-reimbursable during the design stage to target cost and fixed price for construction.

• NEC early warning mechanism and risk-reduction meetings ensured that risks were managed proactively, helping to ensure successful completion on time and budget.