Supply Chain - Wastewater Treatment - Contractors

Beckton Sewage Treatment Works (STW) is the United Kingdom’s largest STW serving a population equivalent of over four million. The AMP7 project is a major £185m investment to increase the site’s treatment capacity for growth, by a population equivalent of 200,000, by extending the existing activated sludge plant (ASP). Beckton STW will receive stormwater from the Thames Tideway Tunnel ‘Super Sewer’ when it is commissioned in 2024. The project will improve resilience of the inlet works by providing more screening and grit removal plant to increase redundancy, the improvements will deliver on a Regulatory Performance Commitment. The project also includes elements of capital maintenance; mainly on electrical infrastructure and sludge treatment, to ensure resilience and effluent quality is maintained. The existing plant The first works at Beckton was built in 1864 by Sir Joseph Bazalgette as part of the revolutionary Victorian sewer network, which drastically improved water quality in the River Thames. The plant has since been extended numerous times and covers over 100 hectares (250 acres). Sewage is received from a large collection of sewers and pumping stations, which all connect to the Northern Outfall Sewer (NOS) that comprises five large brick barrels. Beckton’s flow to full treatment is 27m3/s, with peak storm flow of 32m3/s. The preliminary treatment is by coarse and fine screens, with grit removal located between the screens. Primary treatment is by two banks of rectangular primary settlement tanks (PSTs), each consisting of eight PSTs. The secondary treatment is by a conventional activated sludge process with three separate streams ranging in age, numbered ASP2, ASP3 and ASP4. Each of the ASPs include a set of final settlement tanks (FSTs). Final effluent is discharged to a common channel that leads to the main outfall to the River Thames, upstream of the Barking Creek Barrier. Sludge is treated through a process of anaerobic digestion and thermal hydrolysis. Biogas is captured from the digestion process and generates electricity and heat through combined heat and power engines (CHP). Beckton can produce half of the required electricity to run the treatment process from the CHP engines, and an on-site wind turbine. Digested cake is exported from the site to agriculture and there is an option to process the sludge in the sludge powered generator that also provides electricity for the site. [caption id="" align="alignnone" width="1200"] ASP4 South Tank twin wall under construction - Courtesy of Laing O’Rourke[/caption] What’s being provided? Thames Water has appointed Laing O’Rourke to deliver the project, with multidisciplinary design services being provided by Atkins (SNC Lavalin). The contract was awarded in July 2020, with construction works starting in April 2021 and the works will be completed and handed over in phases throughout 2024. New and existing inlet works A new inlet works will be constructed comprising three lanes that contain coarse (50mm) and medium screens (20mm) provided by Huber Technology, and grit removal plant. One of the existing inlet works lanes will be sacrificed to provide the feed to the new lanes, hence the provision of two additional lanes in terms of redundancy. The constant velocity grit channels have a capacity up to 15m3/s with SAVECO Environmental Ltd supplying traditional grit bridges with an alternative method of grit suction. The associated instrumentation is from Vega Controls Ltd and the automation and control panels for the grit bridges has been designed and built by Te-Tech Process Solutions. Grit classifiers with combined output of up to 88 tonnes/hour and launder channels in this process stream are being supplied by FLSmidth, and Fluid Sealing & Engineering (FSE) Ltd respectively. The process streams for screening and grit removal along with the associated handling plant for the new inlet works follow a similar arrangement to the existing inlet works. The existing inlet works will be supplemented with medium screens, supplied by Huber Technology, in the remaining five lanes to reduce the load passed forward to the fine screens and to improve the reliability of the existing grit removal plant. A significant upgrade to the electrical infrastructure is required with a large glass reinforced plastic switchroom supplied by Morgan Marine. Winder Power Group are supplying the transformer and electrical installation has been subcontracted to AVRS Systems. The new switchroom houses the new high voltage (HV) and low voltage (LV) electrical panels, provided by Siemens and Total Automation & Power (TAP) respectively, supplemented by a new diesel operated generator to improve resilience. [caption id="" align="alignnone" width="1200"] New inlet works under construction - Courtesy of Laing O’Rourke[/caption] ASP4 extension and sludge improvements ASP4 was installed under the last major upgrade at Beckton (by Laing O’Rourke), which completed in 2014 and currently treats up to 8m3/s. This project will provide two new aeration lates in separate tanks, referred to as the North and South Tank. Each are 85m long, 41m wide and 8.5m deep. Four new FSTs will be provided; each being 45m diameter and 5m deep. A new aeration building is required to house blowers for the new aeration lanes with the aluminium clad structural steel building envelope installed by Galloway Construction Ltd. The aeration blowers are supplied by Howden, diffusers by Xylem Water Solutions and new transformers by Winder Power Group as part of a substantial upgrade to the existing electrical infrastructure for the new ASP. The sludge improvements include new Huber Technology raw sludge screens to remove rags and improve resilience in the sludge treatment stream. Sludge treatment capacity improvements, surplus activated sludge (SAS) thickening, is by new gravity belt thickeners (GBTs), supplied by Kent Stainless Ltd in a new building. An extension to the existing sludge cake barn building to increase sludge cake storage capacity is required. The sludge steam has further resilience work by the provision of a polymer dosing facility, new electrical infrastructure, new sludge holding tanks from Stortec Engineering Ltd, and an upgrade to existing tanks. [caption id="" align="alignnone" width="1200"] ASP4 North Tank completed and new blower building cladding underway - Courtesy of Laing O’Rourke[/caption] Capital maintenance There are a number of improvements to the existing site wide electrical infrastructure such as the refurbishment of existing LV panels. The other key element is replacing the outfall channel flap valves to prevent site flooding. Fibre optic network upgrade The site-wide fibre optic network will be replaced as it has reached its design limit and has no capacity to be extended to accommodate the growing operational and performance requirements. Laing O’Rourke and Atkins are working with Thames Water to develop a new network architecture based upon the utilisation of a ‘Layer 3’ backbone network. The design will incorporate four ‘Layer 2’ process networks with firewalls between each Layer 2 network and the backbone Layer 3 network. The updated network architecture will improve resilience and security of the network. Design Around 40% of the project’s civil works have been designed using DfMA (design for manufacture and assembly). The lessons learnt from using DfMA method of construction completed in the previous Beckton upgrade project were implemented in this project. The lessons included manufacturing methods, reinforcement design and detailing, and the use of leaner temporary works required for reinforced concrete structures. Digital Build models produced by Laing O’Rourke have been used to understand the steps involved in the precast construction and identify hazards during pre-construction reviews. [caption id="" align="alignnone" width="1200"] (left) 3D BIM model of new inlet works and (right) new inlet works under construction - Courtesy of Laing O’Rourke[/caption] Another lesson learnt applied was to implement solutions with Engineered Safety in mind, both for temporary and permanent works. Engineered Safety is Laing O’Rourke’s approach, which aims to improve health and safety outcomes for those who design, construct, use, maintain and dismantle the assets (examples outlined later). This approach has helped to identify key hazards further to which simple but effective solutions have been implemented to eliminate or mitigate risks. Notwithstanding the above implemented lessons, one of the key ethos of this project is capture and disseminate new lessons learnt during the design, construction, commissioning, and handover stages of the Beckton STW upgrade and future projects. Digital tools Federated model for coordination and collaboration With the three main organisations (Thames Water, Laing O’Rourke and Atkins) exchanging information, it was necessary to use a common platform to record and share design progress on a regular basis. As such a project 3D federated model has been published on a regular basis and shared via BIM360 and Asite. The model has also been used as a collaborative tool to identify and resolve clashes and for use in workshops and presentations. The model has been produced to BIM Level 2, with Level of Detail 3 (LOD3) for the mechanical and electrical elements of the design, and LOD4 for civil and structural design where third party designs are not required. Whilst Laing O'Rourke's Asite and Thames Water’s TWEXnet Business Collaborator has been used to record outcome of technical assurance and approvals, BIM Collab has been used to monitor resolution of clashes and record actions from pre-construction model reviews. Although traditional spreadsheets were originally developed for reporting design progress, this has gradually been migrated to a Power BI based system. The lessons learnt from this process is now being implemented to monitor and close out HAZOP/OPMAN actions and to plan and monitor progress for handover documentation. [caption id="" align="alignnone" width="1200"] (left) Extract from 3D BIM model: raw sludge screens and (right) raw sludge screen civil works - Courtesy of Laing O’Rourke[/caption] Digital build Laing O'Rourke’s construction assurance procedure requires the use of digital build models prior to construction. Whilst the federated model aims to show the permanent works, the digital build process aims to incorporate both permanent and temporary works requirements by reconstructing the model using 2D outputs from detail design. This has allowed Laing O'Rourke to minimise health and safety risks by planning the build with better accuracy. Drone deploy To monitor progress in construction, drone technology has been used to capture photos and videos. Drone Deploy platform which utilises the rich data captured also allows superimposition of detail design drawings showing outline of permanent works. This tool has been used effectively in collaboration meetings to demonstrate progress or to resolve complex engineering problems, and to plan construction activities. Point Cloud surveys Point Cloud surveys have been used to inform the detail design. This method of survey that capture fine details of location of civil assets and MEICA plant and equipment in 3D format. Although, it requires careful treatment before incorporating into the 3D model. In particular, areas with high density of MEICA plant and equipment such as the sludge tanks, existing grit channel at the inlet works, and existing cake barn ventilation were surveyed using Point Cloud surveys. Design challenges due to scale - constant velocity channel and grit bridges design The scale of the works at Beckton STW created several design challenges around plant sizing, meeting performance requirements and space constraints. One example of this being the grit removal solution on the new inlet works. Conventional design methods for calculating grit channel lengths have been challenged. CFD modelling has been used to size the constant velocity grit channels and to demonstrate the proposed location of flow measurement devices are acceptable. This has reduced the length of the channel by 23m and hence the cost of civil infrastructure. The pumps in the grit bridges are specified to remove up to 3.5kg/s and calls for an automatic system with level instrumentation to detect grit. This would make the classifiers ones of the largest in Europe. Borger Pumps and SAVECO Environmental Ltd are providing rotary lobe type pumps to achieve the specified rate. This design rate of removal is exceptionally high, taking into consideration the incoming grit from the Tideway Tunnel. As detection systems in this scenario are not usually required in the UK, market research had to be undertaken to select the detection system in discussion with the supply chain with their experience from other industries to reach to a solution. [caption id="" align="alignnone" width="1200"] (left) 3D BIM model of new inlet works screens and (right) new inlet works forebay with coarse and medium screens upstream of the constant velocity grit channels - Courtesy of Laing O’Rourke[/caption] Beckton STW: Supply chain - key participants Main contractor: Laing O’Rourke Designer: Atkins UXO pile probing: Safelane Global Limited Piling & earthworks: Expanded Piling Sheet piling: Sheet Piling (UK) Ltd Mini piling: Keller Limited Tunnelling works: Joseph Gallagher Ltd Diving support: DiveCo Marine Limited Structural steelwork & cladding: Gallaway Construction Pipelaying: J Murphy & Sons Limited Structural steel: Reidsteel Precast walls to the FST tanks: A-Consult Ltd Blockwork: Pyramid Builders Limited Precast tank walls: Explore Manufacturing Access steelwork (ASP4): Steelway Fensescure Limited Specialist cable installation: Elsym Installations Limited Electrical installation inlet & ASP4: AVRS Systems Fibre optic installation: VVB Low voltage assembly (inlet): Total Automation & Power Transformers: Winder Power Group Mechanical installation: Fluid Sealing & Engineering Ltd Desalination pipeline diversion: Franklyn Yates Engineering HV switchboard & switchgear: Baldwin & Francis Power management: Regulateurs Europa Ltd HV switchboard & installation: Siemens PLC Inlet works & raw sludge screens: Huber Technology Grit bridges: SAVECO Environmental Ltd Grit bridges control panel design/build: Te-Tech Process Solutions Grit bridges instrumentation: VEGA Controls Ltd Rotary lobe pumps: Borger Pumps Grit classifiers: FLSmidth Blowers: Howden UK Limited Aeration diffusion grid: Xylem Water Solutions SAS gravity belt thickeners: Kent Stainless Ltd Glass coated steel tanks: Stortec Engineering Ltd Odour covers: MSD Design Limited Penstocks & stoplogs: Glenfield Invicta Ltd Scraper bridges: Jacopa Limited Valves: AVK UK Ltd Tank mixing: System Mix Limited Inlet washwater booster set: Crown House Technologies Odour control: Odour Services International Ltd CTM screenings belt conveyors: CTM Systems Ltd Diesel generator: DTGen GRP LVA inlet kiosk: Morgan Marine Limited Polymer plant: Richard Alan Engineering Company Limited Overhead cranes: Bramley Engineering (Lifting Gear) Ltd Skip compactors: Thetford International Compactors FE washwater break tank: Forbes Technologies Ltd Welfare & plant: Select Plant Hire Construction Collaboration The team have strived to maintain collaboration at all levels throughout the project to support health and safety focus, sustainability and dealing with site challenges. In line with the approach in design development and approvals, collaborative planning sessions and workshops have provided great insights in problem solving and the planning of complex tasks, for example the diversion of a 132kV cable, tie in details of the new inlet works to the existing inlet works channel and materials management plan (MMP) for dealing with excavation arisings. [caption id="" align="alignnone" width="1200"] ASP4 North Tank under construction - Courtesy of Laing O’Rourke[/caption] Sustainability The project aims to minimise off-site landfill disposal by re-using spoil for engineering works or redistributing it on site through landscaping activities and creating additional biodiverse habitats. This has been the strategy included in the MMP from the inception of the project. This has been reviewed and updated with new information rising during the construction activities. Any contaminated sections of the excavated materials were monitored with greater scrutiny, supported by chemical testing and analyses. Localised treatment has been implemented complying with environmental standards. For instance, the identification and safe method of disposal of soil contaminated with Japanese knotweed has been carefully selected with engagement from all stakeholders and planning requirements. The above measures have assisted in ensuring construction activities are conducted in a sustainable manner. Another area where sustainability has been considered is in concrete mix design. Due to the large volume of concrete required on site, the use of ground granulated blast furnace slag (GGBS) has been maximised in line within the parameters defined in the project specifications. This has assisted in reducing carbon footprint of the project. Overcoming challenges - Cadent gas main diversion An example how a complex engineering problem was solved in close collaboration with key stakeholders is the resolution of the crossing of the Cadent gas mains to enable the construction of the new inlet works channel. The new structure had to cross an intermediate pressure steel 600mm diameter gas main and a medium pressure 30” cast iron main which then split into two polyethylene (PE) mains. The mains then cross beneath the historical Victorian NOS brick barrels. Engagement with Cadent instigated extensive and detailed assessments of the existing gas mains, this identified the need for the MP cast iron main to be replaced due to excessive ground settlement driven by changes in ground levels. The medium pressure gas main was replaced with a new 750mm steel main, which included a section inserted into a microtunnelled concrete sleeve underneath the NOS. In addition, pipe protection measures using polystyrene blocks and lightweight fill were required to minimise the loadings on the intermediate pressure mains. [caption id="" align="alignnone" width="1200"] New 45m diameter FSTs under construction - Courtesy of Laing O’Rourke[/caption] Engineered safety - DfMA DfMA has effectively been driven by Laing O’Rourke as part of their design development. The level of detail and timing of coordination required between the manufacturing team and designer was clarified early in the programme to ensure an alignment of principles, opportunities, and understanding of the likely constraints. Following are some examples of the benefits that DfMA has given. Aeration tanks and FSTs Precast concrete water retaining solutions are common within the water industry. At Beckton STW, the project has benefitted from incremental innovation of the previous project solution for the construction of the aeration tanks. The twin wall solution has incorporated lessons that resulted in modifying the lateral support beam tie-in arrangement, simplifying the formwork for the pouring of concrete in between the twin wall, and minimising site effort by reducing the complexity at the concrete panel connection interface points. These provided benefit in requiring less working space, plant, and labour, thereby also improving productivity. Furthermore, regarding embedded carbon, the DfMA solution is carbon neutral compared to an in situ tank. Though the same materials are used in similar quantities there has been a 5% reduction in wastage. DfMA has also been used in the design and construction of the final settlement tanks, where post-tensioned precast walls have been utilised by A-Consult Ltd. [caption id="" align="alignnone" width="1200"] Engineered safety: (left) use of access hatch to internally access FST during precast wall installation  and (right) use of RMD soldiers for aeration tank construction - Courtesy of Laing O’Rourke[/caption] ASP4 tank walkway handrailing The installation of walkway handrailing from Steelway Fensecure Ltd has been developed for this project and proven to reduce the site installation period and improved safety by reducing the working at height requirements. The lifting operations have benefitted from the site already having large lift capacity craneage and the construction logistics have enabled access into the working areas to align with the civil engineering works. Systemising pipework and cable containment onto the walkways for future projects are the next generation opportunities to be investigated. Use of RMD soldiers for twin wall propping A simple solution to negate the use of inclined props to create more workspace and reduce hazards is to use RMD soldiers. This required careful planning from the design of twin wall during temporary phase and ensuring appropriate measures are in place within the panels to allow safe fixing of the RMD soldiers in place. Access hatch to FST walls Another example of a simple solution to reduce safety risk is the provision of an access hatch to enable access during the erection of the precast panels, which was developed with the precast wall supplier A-Consult Ltd. This negated the need for providing high level access through temporary staircases and reduced risk of working from height. The above examples emphasize the benefits of DfMA accrued at Beckton STW of an improved product, reduced installation period, and the on-going development opportunity that has made construction activity safer. The project has demonstrated how incremental innovation can be achieved on a relatively new and stable construction method using twin wall construction techniques. [caption id="" align="alignnone" width="1200"] Precast construction of 45m diameter FST - Courtesy of Laing O’Rourke[/caption] Use of non-piled solution As old structures have been historically filled with mass concrete to significant depth, the reuse of these mass fill structures as foundation for new structures was explored as a safer and more sustainable solution. This enabled the project team to avoid the need for mobilising piling rigs, reduce lifting requirements and need for heavy plant and equipment. High-risk service diversions of were also avoided. The SAS thickening system comprising the GBT building, polymer facility, potable water supply facility and the SAS storage tank all are founded on the existing mass concrete foundations. The choice of foundations was supported by structural analyses and further ground investigations. Designer tours To instill a culture of continuous improvement, designer tours encouraged the main designer and those from trade contractors to visit the site, inspect works being undertaken and provide feedback on how hazards are being mitigated on site. The aim being to capture feedback and consider them in future design work on Beckton STW and other projects. Commissioning and handover Preparation for commissioning started well in advance with different sequencing of activities and scenarios discussed with Thames Water and factored in the programme. Several factory acceptance tests (CFATs) have successfully been undertaken for the diffusers in the aeration tanks, inlet works screens, grit classifiers and transformers. The sequence of commissioning activities will lead to a ‘power on’ milestone, followed by dry and wet commissioning when flows are allowed to pass through the works. With a large pool of subcontractors and four main sections of work, Laing O’Rourke are setting up tools and systems to track and collate documentation which will in turn be required to be handed over to Thames Water and for Laing O’Rourke records. This ranges from records of testing, operation and maintenance manuals, training documents, to design assurance documents and quality records. The philosophy adopted is to aim for a continuous handover of documents as and when they are ready, instead of waiting up to the end of the project. [caption id="" align="alignnone" width="1200"] New FSTs with backfilling underway - Courtesy of Laing O’Rourke[/caption] Construction progress The construction of the new inlet work is progressing well with most of the channel structure completed. The upstream and downstream connections to the existing channel will be the last activity before wet commissioning. The new inlet works has transitioned into the mechanical and electrical phase with the installation of the plant items underway. Good progress has been made with the new aeration tanks that are fully constructed and water tested, with diffuser pipework and diffusers installed. The blower house and final settlement tanks have been constructed. The focus is on progressing the aeration blower installation and associated electrical works. The civil works for the sludge area is underway in preparation for the mechanical and electrical plant installation. Overall, the project is on track to complete various works elements throughout 2024 and will be handed over in a phased approach.

Southern Water’s Lingfield Wastewater Treatment Works (WwTW) is located approximately 2km north of Lingfield Park Racecourse in Surrey and serves the population of Lingfield and surrounding villages. An upgrade project is currently taking place which, once complete, will improve the quality of treated water going back to the environment and make sure Southern Water can meet the new environmental standards set out by the Environment Agency in the Water Industry National Environment Programme (WINEP3). The project started on site in August 2023 and the main works are due to be complete in December 2024. Project drivers The Lingfield upgrade was required to fulfill the following drivers: WINEP - P removal (regulatory date 22 December 2024): Lingfield WwTW is already required to achieve P removal, but a more stringent permit will be introduced at the site this AMP. New assets are required to meet the revised permit conditions (phosphorus standard of 0.3mg/l (mean), Fe: 4mg/l (95%) 8mg/l (U/T)) as identified in the Water Framework Directive (WFD) IMPg-P driver in the Water Industry National Environment Programme (WINEP3). U_iMP5 Programme - increased flows (regulatory date 31 March 2025): As well as the Water Framework Directive quality driver, a further project driver is to implement improvements at the site to facilitate an increase of the full flow to treatment (FFT) from 83 l/s to 127 l/s. This will involve the installation of new process assets to provide additional biological treatment capacity and accommodate projected population growth to the design horizon of 2035. The projected population equivalent (PE) at the design horizon is 13,390. Project scope

This work is being undertaken by CMDP, a joint venture between Costain and MWH Treatment. As one of Southern Water’s Delivery Partners for its AMP6 and AMP7 Capital Investment programmes, CMDP is delivering a range of schemes to maintain and improve Southern Water’s water supply and waste water treatment works, including Lingfield WwTW.

[caption id="attachment_15885" align="alignnone" width="1200"] (left) New trickling filter pumping station pipework and (right) chemical dosing facilities - Courtesy of CMDP[/caption]

P removal: The main components of scope to address the P removal driver are as follows:

Upgrade the existing 30m3 ferric dosing facilities to incorporate a second dosing location: Point of Application 1 for ferric is as existing at the end of inlet flume. Point of Application 2 for ferric will be into a static mixer on the new tertiary treatment feed pipework. New 40m3 sodium hydroxide dosing facility with a single point of application at the settled sewage pumping station (upstream of the biological treatment stage). New tertiary treatment plant (TTP) comprising a Bluewater Bio Ltd FilterClear package. Make the existing moving bed filters redundant. Convert the existing sand filter pumping station (PS) into TTP Feed PS (sized to accommodate new peak flow through works). New low voltage assembly and control panel to serve the above.

U_IMP5: The main components of scope to address the U-IMP5 driver are as follows:

Replace crude sewage pumps with larger capacity units and modify pipework and access to accommodate and enable certification of inlet flow meters at FFT. New 12.5m diameter radial humus settlement tank with half bridge scraper. Replace final effluent/outfall pumps with larger capacity units. New biological trickling filter feed pumping station. New 31m diameter biological trickling filter with a working volume 1377m3. Cross-site pipework to integrate the new filter into the existing treatment works.

Other works: In addition to the above, the following site-wide improvements form part of the project:

Upgrade the site power supply. Upgrade site telemetry system. Replace the existing standby generator with a larger capacity unit. [caption id="attachment_15880" align="alignnone" width="1200"] Trickling filter tank precast panel installation - Courtesy of CMDP[/caption] Lingfield WwTW: Supply chain - key participants Client: Southern Water Delivery contractor: CMDP Costain MWH Treatment JV Civils engineering works: Coleman Utilities & Construction FilterClear tertiary treatment plant: Bluewater Bio Ltd Trickling filter bed construction: Day Contracting Mechanical contractor: Pipe Systems Ltd Electrical contractor: Field Systems Design LVA/systems integration: TAP - Total Automation & Power Chemical dosing (ferric): Lintott Control Systems Chemical dosing (caustic): Bridges Electrical Engineers Ltd Humus tank & filter arms: Tuke & Bell Filter media: Day Aggregates Scraper bridge: Jacopa Flow meters: Siemens Pumps: Xylem Water Solutions Generators: P&I Generators Ltd [caption id="attachment_15875" align="alignnone" width="1200"] Trickling filter pipework - Courtesy of CMDP[/caption] New biological trickling filter bed and feed pumping station

Part of the project is to install a new 31m biological trickling filter to supplement the existing secondary treatment capacity at the site. Space limitations at the site necessitated re-development of an area previous occupied by sludge storage bays. The existing structure was broken out only where required, with the aim of minimising the volume of waste generated for off-site disposal.

The filter construction comprised reinforced concrete base slab and precast wall sections/tiles, blast furnace slag media, new motor driven distribution arms, and inlet and outlet pipework. Also required is the installation of a new feed pumping station, consisting of a new wet well, duty/standby variable speed pumps and the associated pipework, including a cross site rising main to the new filter.

New humus tank

A new below-ground 15m radial humus tank has been installed as part of the upgrade. The tank is 7m at its deepest point i.e. the central sludge hopper and is fitted with a conventional half-bridge rotating scraper.

Construction of the tank was significantly constrained due to the close proximity of existing assets and size of the site, as well as the enormity of buried services in this area, meaning a traditional rectangle cofferdam was not viable. Therefore, a circular pre-driven sheet with an external ring beam was designed to utilise the available space on site and overcome the multiple constraints.

[caption id="attachment_15881" align="alignnone" width="1200"] New Humus tank construction and temporary works access - Courtesy of CMDP[/caption] Tertiary treatment plant

A new tertiary treatment media filter plant was supplied by BlueWater Bio Ltd and included four multimedia filter cells, backwash and sludge transfer pumps, clean and dirty backwash tanks, and interconnecting pipework.

As mentioned previously, in relation to the trickling filter, the new tertiary plant was located in an area previously occupied by sludge storage bays to make best use of available land within the existing site boundary.

The existing electrical distribution system at Lingfield WwTW requires upgrading to incorporate the new and retained process loads. The existing system consists of a main distribution board housed within the main control building and fed from a 315kVA 11kV/433V transformer. The existing main distribution board will be retained and back fed from a new main LV assembly switchboard LVA1 to increase the capacity of the site.

Challenges

One of the main challenges facing the site team at Lingfield was the considerable number of previously unidentified services in the area where construction was required.

There were approximately 140 services which needed to be found and avoided, and this unexpected challenge was overcome by the diligence and professionalism of the site team, who utilised Cable Avoidance Tools (CATs) and Signal Generators (Gennys) and Vac EX as well as multiple trial holes. There have been and estimated 45 permits to dig raised in order to safely establish the whereabouts of these buried services.

[caption id="attachment_15874" align="alignnone" width="1200"] Clean and dirty backwash tanks and the FilterClear tertiary package plant - Courtesy of CMDP[/caption]

Another key challenge faced by the team at Lingfield was posed by the lack of space available on site. To overcome this challenge, the team utilised the expertise of CMDP parent company Costain in the design a circular retaining wall for the new humus tank.

The site itself is also on a flood plain and due to the increased rainfall and weather conditions earlier in the year the site was in fact flooded and needed to be pumped out to allow works to continue. In addition, this site only has one access road in and out therefore meaning careful planning of deliveries and visits is required to minimise any traffic issues being raised.

The challenges themselves became somewhat of a success for the team and can be used as a benchmark for overcoming similar constraints in future projects.

Social value

Social value is an important part of all projects, and both Southern Water and CMDP maintain a commitment to improve the communities in which they operate. The aim is to capture the most relevant information of how communities are impacted and the social value portal’s Themes, Outcomes and Measures (TOM) system was used to measure and report on the worth of the social value activities undertaken by both the project team and CMDP as a whole.

Southern Water and CMDP’s aspiration is to act beneficially and integrate into community life by contributing to environmental improvements and deterring any negative impact, using a local workforce and encouraging individuals into work while maintaining a high level of wellbeing for staff and visitors.

[caption id="attachment_15878" align="alignnone" width="1200"] Lingfield WwTW - Courtesy of CMDP[/caption]

It is important to establish meaningful opportunities for volunteering and donating which can leave a lasting legacy when work is complete and the site team has moved on. Fundamentally, Southern Water and CMPD want to ensure that each site has a robust communications plan which can include a social value tracker where actions can be measured and their impact quantified.

The area in which the works are being conducted has little residential impact due to the location of the site, however the following areas were identified in which positive impact could be made:

Supporting the community by, where possible, employing local people to join the team and make a positive impact. As part of our commitment to positive change in construction, CMDP have registered with the Considerate Constructors Scheme and achieved a score of 45 out of 45 for the site’s most recent assessment visit earlier this year. The assessor noted that due to the isolated location of the works, and its location in the countryside, the team have the responsibility to make sure there is no detrimental effect on or caused to the area, which they advised the team clearly demonstrated. Bats were nesting/roosting behind the site cabins and to minimise the noise impact and any disturbance to the bats, acoustic barriers were installed. Project engineer (Xenia Magdaleno-Tseng) is registered as a STEM ambassador and has judged a local school engineering competition. The STEM Ambassador Programme is an important part of CMDP’s work to inspire the next generation into the industry and capture interest. Where there currently is a skills gap, the need to be inclusive and promote not only the water sector but construction as a whole drives CMDP to enter into volunteering opportunities and learning goals for students within the local community and adjoining areas. The CMDP project engineer has won an award within the parent company of Costain, which recognises staff that live the core values and behaviours of the business; a difficult award to win due to the competition involved, but this highlights the dedication and commitment of the Lingfield WwTW project team. [caption id="attachment_15876" align="alignnone" width="1200"] Project Engineer Xenia Magdaleno-Tseng in front of the new trickling filter bed - Courtesy of CMDP[/caption]

There is also an aim, in collaboration with CMDP’s Environmental Manager, to install bat boxes upon completion of the works which will aid local natural habitats and act as an environmental enhancement. The Lingfield WwTW site team continue to seek further opportunities to contribute to the ecological maintenance of the area, such as litter picking the site. The wider team at CMDP also scope the areas further afield (due to the isolated nature of this site) to maximise engagement with schools and local charities.

Conclusion

At the time of writing (August 2024), the Lingfield WwTW upgrade goes from strength to strength, meeting milestones and continuing to have minimal impact on the surrounding area and community. The project has overcome a variety of challenges through thoughtful design and on-site innovation and is on schedule to achieve completion within the regulatory programme dates.

In accordance with our commitment to reduce carbon footprint, suppliers have been sought where possible from within a 20-mile radius of the site. The site team has also used local amenities and services throughout the duration of the project which should have a positive impact not only through engagement but also the financial injection into the community.

With the civil construction stage almost complete, work is currently being undertaken on the Humus de-sludge chamber construction and continuation of site wide ducting installation. Mechanical installation work is ongoing, with a sodium hydroxide dosing kiosk access platform to be installed with tertiary area and final effluent pumping station pipework to be completed. Electrical installation is ongoing with cable glanding continuing for the new LVA panels and the tertiary treatment area. This will be the final part of the construction phase.

The project benefits from continued collaboration of the Southern Water and CMDP teams. In addition to virtual communications, the teams have regular face to face meetings to discuss the project and make any improvements required; benefiting not only the current works but the legacy which is left for local customers.

Monkmoor Sewage Treatment Works currently serves a catchment of 116,000 (PE) in Shrewsbury, which is expected to grow to 146,000 by 2033. The works is a conventional activated sludge plant (ASP) and treats a combination of domestic and trade waste, consisting of landfill leachate, wastewater from other traders, meat process wastewater and sludge imports. The existing site consists of an inlet works, four storm tanks, four primary settlement tanks, four ASP lanes, four final settlement tanks, and a sludge treatment facility, which digests indigenous and imported sludge from surrounding sites. Tightened permits

The table below shows the current and revised:

Current permit Revised permit BOD 25 mg/l BOD 25 mg/l SS 45 mg/l SS 45 mg/l NH3 10 mg/l NH3 10 mg/l P - P 1 mg/l Fe - Fe 4 mg/l

The solution to meet the tightened P permit was to provide a new chemical dosing facility and additional final effluent monitoring equipment. In order to meet the growth driver, Membrane Aerated Biofilm Reactor (MABR) units were to be installed into the existing anoxic zones.

The aim was also to reduce the mixed liquor concentration within the ASP, thereby reducing the load to the final settlement tanks, helping to counteract the additional solids produced by chemical dosing. Installing MABR also had a CAPEX and OPEX saving over building new ASP lanes. The total value of the project was £6.2m.

[caption id="attachment_14838" align="alignnone" width="1200"] (left) Google Maps image showing Monkmoor STW and (inset) the existing anoxic zone - Courtesy of Mott MacDonald Bentley[/caption] Chemical dosing and FE monitoring

Two 60m3 ferric sulphate storage tanks were installed to meet the new phosphorous consent. The dose location was at the top of the ASP feed screw pumps as this is a turbulent area.

Existing ducts were used to cross the road to avoid breakout of concrete. The tanks were placed in a bund and instead of a delivery lay-by, sleeping policemen were used to contain the drainage in the delivery area from the rest of the road. As traffic will be stopped during delivery, this separates the delivery personnel from the live traffic.

The drainage is designed to gravitate from the chemical dosing area to the settled sewage. This is beneficial as the alternative location, the inlet works, is well over 300m away. This prevented additional excavation and removed the need for an additional pump station.

In the existing final effluent chamber, new iron and phosphorus monitors were installed. The existing kiosk was replaced, and existing monitors were relocated to the new kiosk, which was placed on the opposite side of the chamber to the existing, which allowed reuse of existing cables.

[caption id="attachment_14840" align="alignnone" width="1200"] (left) MABR blower from Aerzen Machines and (right) two 60m3 ferric sulphate storage tanks installed in the chemical dosing area - Courtesy of Mott MacDonald Bentley[/caption] Introduction to Membrane Aerated Biofilm Reactor

The Membrane Aerated Biofilm Reactor (MABR) from OxyMem Ltd uses gas permeable polydimethylsiloxane (PDMS; also known as silicone) hollow fibre membranes, which supply oxygen for aerobic oxidation as well as providing a surface for the growth of the biofilm.

PDMS membranes are dense; meaning they have no pores. Process air is fed to the PDMS hollow fibres and the oxygen diffuses through the PDMS by molecular diffusion into the biofilm. This can simply be described as bubble-less aeration. The biofilm, which receives its oxygen directly from the surface on which it is growing, performs biological treatment for carbon and nitrogen removal, the two major pollutants in municipal wastewater.

Each OxyMem MABR module is made up of individual membrane fibres grouped together into bunches containing 550 fibres. A cassette is made up of 25 of these bunches, each potted into a PVC header. A number of cassettes are then placed into a module and connected to the inlet and outlet distribution manifolds.

As process air is fed to the module through the top distribution manifold, it travels through the fibres and is collected at the bottom manifold. The exhaust air collected is used to power two airlift pumps, so no moving parts or extra power is required. The airlift pumps ensure the zone below the modules is mixed and helps to ‘pull’ MLSS into each module. The MABR modules are designed with a top cowling that prevents bypass and ensures all the flow must travel vertically past an established biofilm on the network of high surface area membranes before it can exit the module and MABR zone.

Scouring the biofilm with air is essential to remove excess sludge and keep the biofilm thickness optimal during operation, maximising the MABR performance. Scouring is achieved using a dedicated scour blower, which supplies air through a distribution grid, installed at the bottom of the MABR modules, at a high flow rate in discontinuous mode. This grid is integrated within the module. [caption id="attachment_14826" align="alignnone" width="1200"] (left) MABR units being readied for crane lift and (right) lowering an MABR module into the support steelwork installed on the ASP anoxic zone - Courtesy of OxyMem Ltd[/caption]

The MABR system implemented at Monkmoor is an MABR integrated with activated sludge (called MABR-IFAS or Hybrid-MABR), where the modules are dropped into the existing ASP anoxic zone. There are several key benefits to using an MABR system:

Additional biological capacity. Minimal to zero additional footprint. No need to drain tanks (in most cases). Reduction of process spikes. Ease stress on existing assets. Low process emissions. Resilient process.

At Monkmoor, due to the growth driver, more ammonia needed to be removed from the ASP lanes. One option was to build more lanes, but the MABR solution allowed a retrofit of the existing tanks.

The requirement was that 162 kg N-NH4/d must be removed from the anoxic zones. Therefore, 48 (No.) OxyMem MABR units were installed; 12 per lane. The modules were grouped into banks of three; with each lane having four groups. Process air is supplied continuously to each module and the scour cycle operates periodically on each bank. To provide both process and scour air to the modules, four 15 kW blowers were installed. The process blowers were sized to provide 712 Nm3/hr of air and the scour blowers sized for 577 Nm3/hr of air.

MABR technology has previously been installed at Spernal STW but only ten OxyMem and five Veolia units had been installed as part of a trial. Monkmoor was the first large-scale installation of MABR within the UK.

[caption id="attachment_14839" align="alignnone" width="1200"] MABR installation - Courtesy of OxyMem Ltd[/caption] Monkmoor STW: Supply chain - key participants Client: Severn Trent Principal designer & contractor: Mott MacDonald Bentley MABR technology: OxyMem Ltd Mechanical installation: Alpha Plus Ltd Electrical installation: Lloyd Morris Electrical Ltd Chemical dosing: Colloide Quality monitoring: Servitech International Ltd MCC: CEMA Group Blowers: Aerzen Machines MCC kiosk: Dutypoint Ltd Design decisions

Throughout the design process, MMB liaised with the Severn Trent operations team, to ensure they were onboard with the new assets, helping to give the team confidence in the design.

The mechanical installation was completed by Alpha Plus Ltd, who worked with MMB to design and install the steelwork to support the modules, and the pipework connecting the modules to the blowers. The design of the steelwork required consideration of the interfacing with the existing walkways. The key benefit of the MABR solution is the modifications to the ASP enabled the whole install to be undertaken whilst keeping the existing process live. This was a key consideration when deciding how to support the modules.

The final design involved steelwork spanning across the existing anoxic zones and dropping down underneath the existing walkways, to be supported by the concrete walls of the ASP. Structural checks were completed to ensure the existing ASP walls were suitable.

[caption id="attachment_14827" align="alignnone" width="1200"] MABR support steelwork - Courtesy of OxyMem Ltd[/caption]

Access was required in order to make the connections for the process and scour air. There were many options considered in terms of how access should be provided. By holding a design sprint, it was decided that in order to avoid installing walkways over aerated water, the existing walkways would be used as the main access. Installing additional walkways would reduce the area in which MABR units could be installed and would provide an access platform that would require authorised entry only.

The modules were installed using a lifting frame that enabled installation without needing access to the top of the modules. The pipework was made using a man riding basket. After installation, limited access is required so a non-permanent, temporary access solution can be used. By considering the interfaces with the existing walkways and the access challenges they posed, it was possible to complete the installation without draining the lanes. The modules were lifted into the tank using a crane and the existing crane pads on site were reused for this.

Flexible hosing attached to the module, supplied by OxyMem Ltd, was attached using a camlock to the process and scour air manifolds. Banks of three modules were connected to these manifolds. The manifolds were connected to common pipe runs back to the duty/standby process and scour blowers. It was important to ensure the aeration pipework had falls to low points to enable condensate collection and drains. When designing the pipework and steelwork, consideration for operator access for maintenance was also a priority. For example, the existing mixers within the anoxic zones were retained and need still to be able to be lifted out for maintenance, the layout of the new process enabled this. The pipework was designed so that it creates a vertical gallery on the main ASP walkway, enabling access to both new and existing equipment.

[caption id="attachment_14822" align="alignnone" width="1200"] MABR module being lowered into place within a bespoke steelwork frame - Courtesy of OxyMem Ltd[/caption]

For the steelwork, there were three options; 316 stainless steel sections, a 316 stainless steel lattice or FBE coated mild steel. It was not possible to procure the stainless-steel section sizes required. A stainless-steel lattice would be more readily available than stainless steel sections. However, there would be an increased risk of ragging, a lot of welding required, and it would be difficult to keep in tolerance due to the tendency of stainless steel to warp/pull forwards following welding. Additionally, if there was any ragging, this could lead to the water becoming stagnant and therefore corrosive to the stainless steel. In the end, despite possible re-coating being required if cut or drilled, FBE coated mild steel was selected. This was because the section sizes were more readily available, pipe support attachments would be easier as they could be bolted onto the beam flange, there would be possible cost savings over stainless steel and there was no increased risk of corrosion.

In order to monitor the performance of the MABR units, DO, redox and pH meters were installed into the anoxic zone on one lane. Additionally, an ammonia monitor was installed on the ASP distribution chamber and at the end of one of the anoxic zones.

These monitors were designed to be moved between lanes in to enable a performance assessment of each lane if required. An additional off-gas pipe was added to the first bank of modules on each lane so that if required, in the future, additional monitoring of the off-gas could be completed to determine the potential of MABR units to remove NOx.

The MABR units were constructed off-site in OxyMem Ltd’s factory. On site, the top cowling was installed, and the units were lowered into the lanes.

Conclusions/summary

A successful large-scale installation of MABR was completed, along with chemical dosing and FE monitoring equipment. Data is still being collected to show the performance of the MABR units but initial results are showing that the units are meeting the required ammonia removal target. The biofilm grew quickly and the required removal was taking place within a month.

North-west of Nottingham and separated by the River Erewash, two of Severn Trent’s sewage treatment works are situated within 2.5km of each other; part of the legacy of the times of the public statutory undertakers. Heanor Milnhay STW in Derbyshire has a dual-stream process, with part of the flows going through trickle filters and the rest being treated in a conventional activated sludge plant. It treats up to 258 l/s from a population equivalent of 41,000 from the Heanor catchment. Newthorpe STW in Nottinghamshire, which also serves a PE of approximately 41,000, is a filter treatment process with a maximum capacity of 324 l/s. Project objectives The objectives of the project are to improve the quality of the effluent at Heanor Milnhay STW and Newthorpe STW to meet the Water Framework Directive (WFD) requirements set out in the National Environmental Programme (NEP). This is to be achieved through the transfer of flow to full treatment (FtFT) from Heanor Milnhay STW to Newthorpe STW for combined treatment. As part of the NEP commitments to meet the obligations of the WFD in AMP7, a new phosphorus (P) permit of 0.2 mg/l will be introduced on 22 December 2024. The target price of the project is £35.8m. Project summary Heanor Milnhay: Heanor Milnhay will be decommissioned once construction at Newthorpe is complete, with the site only retaining its storm tanks. The storm capacity will be increased from 2,000m3 to 7,000m3 by the transformation of its two primary settlement tanks into new storm tanks and the construction of an extra blind tank. A combined sewage overflow chamber will split the storm flows from the flows to be treated at Newthorpe, which will be pumped through a dual rising main to the new works. [caption id="" align="alignnone" width="1200"] Google Maps image showing general scheme overview - Courtesy of Mott MacDonald Bentley[/caption] Newthorpe: At Newthorpe, the secondary and tertiary treatment will be decommissioned. Only the preliminary treatment (screening and grit removal) and the primary settlement tanks will be retained as part of the new process stream. The extension, which will be built on the field adjacent to the existing works, will use an Enhanced Bio-Phosphorus Removal (EBPR) process, in a modified University of Cape Town (UCT) configuration. This process aims to reduce chemical consumption using polyphosphate-accumulating organisms (PAO) to eliminate phosphorus. Newthorpe STW extension Newthorpe STW will see a complete transformation. The new process will be capable of treating double the flow in a similar footprint to the existing works. The extension will consist of: New inlet works to treat the flows transferred from Heanor Milnhay STW: While the Newthorpe flows will still be treated at the existing inlet works on site, Heanor Milnhay flows, which will arrive at the site crude, will go through a 2D 6mm escalator fine screen provided by Longwood Engineering and a Crossflow grit detritor provided by Tuke & Bell, before entering the new treatment. Combination chamber with a high flow overflow: The new chamber will combine the flows coming from Newthorpe, which have been settled in the existing primary settlement tanks, with the flows coming from Heanor Milnhay. Heanor Milnhay flows will not be settled before entering the secondary treatment to provide the EBPR with the right level of load. However, the process is protected from highly diluted load flows with a high-flow overflow, that will allow flows above 66% of FtFT to bypass the anaerobic and anoxic section and go directly to the aerobic treatment. [caption id="" align="alignnone" width="1200"] Newthorpe STW extension Revit model - Courtesy of MMB[/caption] An anaerobic and anoxic tank, with a capacity of 2,438m3 per section (4,876m3 in total): To provide the right level of tank in series and mixing in the system, each tank consists of three equal pockets with submersible mixing. The recirculated active sludge (RAS) and the liquors from the thickening of the surplus active sludge (SAS) will join the process in an intermediate chamber located between the anaerobic and the anoxic sections. The tank is a 40m long, 25m wide and 6.5m high structure. A 4-lane activated sludge plant (ASP) holding a total process volume of 20,000m3 (5,000m3 per lane): This is the biggest structure on site; 90m x 42m and a height of 6.5m. Each line has a swing zone that turns 3,000m3 of volume from aerobic to anoxic in summer. Sulzer are providing the blowers and Xylem Water Solutions provides the aeration grid and pipework for the tank. Final settlement tanks: 3 (No.) 33m diameter final settlement tanks designed and built by Tank Consult Ltd, with full scraper bridges designed by EPS Water. Mixed media filtration: Consisting of four horizontal vessels supplied by Bluewater Bio Ltd, this is the largest plant of this kind for the treatment of wastewater installed in the UK. Sludge thickening: Comprising Alfa Laval gravity belt thickeners aided by polymer dosing by Richard Alan Engineering. Chemical dosing: Alkalinity dosing to limit ammonia from Lintott Control Systems and ferric dosing to trim P to meet the new tightened permit of 0.2mg/l from Colloide. [caption id="" align="alignnone" width="1200"] Anaerobic & anoxic tank construction progress - (July 2023) - Courtesy of Mott MacDonald Bentley[/caption] Newthorpe STW: Supply chain - key participants Client: Severn Trent Principal designer & contractor: Mott MacDonald Bentley FRC: Bell Formwork Services Ltd Design/build of FRC final settlement tanks: Tank Consult Ltd Rising main HDD: Johnston Trenchless Solutions (JTS) Tertiary solids removal: Bluewater Bio Ltd Gravity belt thickeners: Alfa Laval Inlet screens: Longwood Engineering Company Ltd Grit removal plant: Tuke & Bell Scraper bridges: EPS Water Glass-coated steel tanks: Goodwin Tanks Aeration diffusers for ASP: Xylem Water Solutions MCCs: CEMA Ltd Kiosks: Morgan Marine Coated pipework & wall starters: George Green (Keighley) Ltd Polymer dosing: Richard Alan Engineering Alkalinity dosing: Lintott Control Systems Ferric dosing: Colloide Mixers, blowers & submersible pumps: Sulzer Pumps Wastewater Ltd Progressive cavity pumps: NOV Booster pumps: Grundfos Valves: AVK UK Ltd Lifting equipment: T Allen Engineering Services Ltd Steelwork: Galliford Try Fabrications Fencing: Town & Country Fencing (Midlands) Ltd Carbon reduction One of the main aims for the Newthorpe delivery team has been minimising the carbon footprint of the project, using the PAS2080 carbon hierarchy. Build nothing: The original scope of works included new inlet works to treat Newthorpe STW flows. However, after a structural inspection of the existing inlet works, and given that the design flows were not increased, it was proposed to reuse the existing structure, with some minor modifications, just replacing the mechanical equipment. The estimated carbon saving was circa 250 tonnes of CO2. Build less: A joint effort of the Mott MacDonald Bentley process and structural team lead to a big carbon saving in the ASP structure. The process team identified the opportunity of reducing one lane from the outline design, with no detriment to the process. At the same time, the structural team developed a solution with variable wall and slab thickness to optimise the concrete. In total, it was estimated that the embodied carbon of the structure was reduced by 400 tonnes. [caption id="" align="alignnone" width="1200"] Final settlement tanks construction progress July 2023 - Courtesy of Mott MacDonald Bentley[/caption] Build smart: Due to the depth of the final settlement tanks into the ground, flotation was the limiting factor in the design. In the preliminary calculations, the estimated slab thickness required for the tank to float in a maintenance scenario was above 1000mm. The project team, therefore, challenged themselves to try to achieve a more sustainable solution. The outcome was to install an active drainage system that, in case of maintenance, would lower the groundwater level to 2m below the final ground level. That reduced the slab thickness to 400mm, without having a major impact on the operation of the plant, as this drainage system will only be required during maintenance scenarios where the tank needs to be emptied. Build efficiently: To carry out the earthworks for the new site, the site team has used GPS-intelligent plant that, utilising a 3D model of the ground, reduced the plant-operator interface on site, improving H&S as well as efficiency. The excavated ground has been re-used to screen the site and provide biodiversity net gain, instead of having to transport it off-site. Progress to date Construction started in the summer of 2022 and at the time of writing, July 2023, is progressing well: The ASP slab is complete and the ASP walls are 70% complete and there is similar progress on the anaerobic/anoxic tank. Both structures will be ready to start hydrostatic testing and installation of M&E equipment by early Autumn. [caption id="" align="alignnone" width="1200"] ASP Tank construction (July 2023) - Courtesy of Mott MacDonald Bentley[/caption] FST1 is now completed and undergoing hydraulic test and FST2 and FST3 are under construction. Construction of the inlet works for the Heanor Milnhay flows and the MCC basement are due to start shortly. The first section of the rising main connecting Heanor Milnhay and Newthorpe are underway with a planned completion by the end of 2023. The rising main design has been challenging due to the number of features and a large number of external stakeholders requiring complex management by MMB. While half of the rising main will be installed by open trench methodologies, almost 1.2km will be built using directional drill, in two separate sections. The first section will cross the River Erewash, the Erewash Canal, and the disused Nottinghamshire Canal. The second section will follow the alignment of Newmanleys Road and will avoid any need for road closures or traffic management in the area. Particularly challenging is the section closer to the works, which has old mine works recorded, and therefore needs special measures to minimise the risk of encountering unknown mining features. In Heanor Milnhay STW, the redundant assets in the area where the new assets will be built have been demolished, however, the construction on site is subject to the completion of the first directional drill shot and has not yet progressed. [caption id="" align="alignnone" width="1200"] (left) Ground modelling to explore coal seams and (right) detail of rising main welding area - Courtesy of Mott MacDonald Bentley[/caption] Summary Newthorpe and Heanor Milnhay STWs are being merged together in one of Severn Trent's major AMP7 projects, with Mott MacDonald Bentley as principal designer and contractor. The expansion of Newthorpe STW will make it one of the largest enhanced bio-phosphorus treatment sites in the region, covering a population equivalent of 100,000; achieving a tightened permit of 0.2 mg/l while minimising the use of chemicals to remove phosphorus. The construction of the project is ongoing with the biggest structures set to be completed in Autumn 2023. The expected completion date of the project, including the biological maturation of the EBPR is December 2024.

Guildford town and the surrounding residential areas are currently served by an existing sewage treatment works (STW) located adjacent to the River Wey, just north of the town centre. The land which this occupies has been identified as part of the Slyfield Area Regeneration Project (SARP), which includes the new Weyside Urban Village (WUV). This mixed-use regeneration project will include circa 1,500 new homes, new community facilities and 6,500m2 of commercial space to improve the local area. Thames Water Utilities Ltd (TWUL) is working in partnership with Guildford Borough Council (GBC) to move the STW to a new location, which is not suitable for housing.

The location chosen is on the north-east extent of the existing Slyfield Industrial Estate and is on an area previously used as a landfill site. In August 2023 Water Projects published a case study which provided insight into the extensive pre-construction design for civil and process engineering elements of the project. This article delves into the construction of the project and provides an update on the significant progress made to date on site.

Site historical use

The site for the new STW is approximately 70,000m2 and was previously used as a landfill site. It had originally been used as sand and gravel quarries and then subsequently used as landfill from the 1960s to the 1980s.

The landfill material is generally domestic and light industrial. It consists of black bag waste, timber, plastics, fabrics but contains fragments of asbestos and other materials.

The site was capped off with a granular layer in the early 1980s and has laid dormant ever since. The landfill depth varies across the site from between 2m and 6m thick. This then overlies an alluvium layer, sands and gravels and London Clay. The depth of the London Clay is approximately 10m below existing ground level.

[caption id="attachment_16131" align="alignnone" width="1200"] A screenshot of the 3D model used for design and construction - Courtesy of Bam Nuttall Ltd[/caption] Civil engineering: Basis of the design

Typically, major structures within a sewage treatment works are built below or partially below ground level to maximise gravitational energy. The new Guildford STW differs in that the strategy is to deliberately design and build above ground as far as practicable.

This is to minimise the disturbance to, and removal of the existing landfill thereby reducing the impact on the environment and the cost of disposal.

Undertakings

After a period of Early Contractor Involvement, Thames Water awarded a contract to BAM-Enpure Joint Venture (BEJV) in 2021 to design, build and commission this significant new works and once operational, to de-commission the existing works.

BEJV is a non-integrated joint venture, formed specifically to combine the excellence of experienced civil engineering contractor Bam Nuttall Ltd and the process engineering/MEICA specialism of Enpure Ltd to deliver a turnkey solution for Thames Water. The workscope split is as follows:

Bam Nuttall Ltd: Civil engineering workscope Principal contractor Civil engineering design Ground stabilisation & piling Structures Underground pipework Tunnels, shafts and connections Buildings Outfall pipeline & structure Roads, fencing & general civil engineering works [caption id="attachment_16143" align="alignnone" width="1200"] Construction of the high level inlet works structure - Courtesy of Bam Nuttall Ltd[/caption] Enpure Ltd: Process engineering/MEICA workscope Principal designer MEICA design Process design Mechanical works Electrical works Control systems Commissioning

Decommissioning of the existing STW will also be undertaken by BEJV, in addition to working collaboratively with TWUL operational and networks teams to integrate existing TWUL operational assets into the new sewage treatment works.

Site trials

BEJV undertook a series of site trials in 2021/2022. The purpose of this was to investigate the proposed ground improvement techniques further in order to validate proposals and inform detailed design. There are a combination of techniques which interface with each other in a complex manner.

The trials also gave important information about potential effects to both leachate levels and ground gas within the existing landfill to ensure there would be no impact on environment, ecology and human health.

Four trial areas were chosen, to provide a variety of conditions and in each of these areas a set of boreholes was established at increasing offsets away from the trial areas. These boreholes contained monitors for both leachate levels and ground gas volumes and were monitored 24/7. In addition, noise and vibration monitoring was also undertaken. [caption id="attachment_16140" align="alignnone" width="1200"] (left) Rapid impact compaction underway and (right) a selection of site plant in use - Courtesy of Bam Nuttall Ltd[/caption]

The three techniques tested, and subsequently used within the works were as follows.

1. Rapid impact compaction (RIC): RIC was undertaken to remove the risk of long-term settlement to the landfill. Whilst the main structures would be supported on piles, this was to remove the risk of long term ground settlement underneath and around the structures. RIC is a method of imparting energy to the ground using a repeated but relatively short drop-weight, where a base plate is in constant contact with the ground. It is undertaken on a pre-determined grid pattern. At Guildford a 9T hammer was chosen, fitted to a 35T base machine and working on a 2.5m x 2.5m grid. Each ‘pass’ of the technique used 40 blows at each point.

Within the trial areas the technique was tested with 1, 2 or 3 passes (ie, 40, 80 or 120 blows per location). Cone penetrometer tests were used to measure the extent of deep level ground compaction before and after the trials. The continuous monitoring from the boreholes demonstrated that at each ‘thump’ of the ground there was no discernible change in leachate levels or ground gas volumes, and that there was no dispersal of leachate happening throughout the landfill.

From the trials it was determined that all areas of the site that are being built on should receive either 1 or 2 passes of RIC for the permanent works.

[caption id="attachment_16135" align="alignnone" width="1200"] (left) Driving precast concrete piles and (right) vertical rigid inclusion installation - Courtesy of Bam Nuttall Ltd[/caption] 2. Precast driven piling: The main structures and pipelines are founded on precast driven piles. These are end-bearing into the London Clay, approximately 10m below ground level. Precast driven piles were chosen as the solution as the operation does not bring any landfill to the surface. Various size piles were driven to various depths and tested with both dynamic and static tests. Borehole monitoring showed that there was no discernible change to leachate and ground gas levels and that there was no dispersal of leachate happening throughout the landfill.

3. Vertical rigid inclusions (VRI): VRIs are mass concrete piles which are used for lightly-loaded structures and areas such as roads and hardstandings. They are a displacement pile, with the surrounding soil pushed sideways by an auger. As the auger is withdrawn the resulting void is filled with concrete up to ground level. They therefore work by increasing the density of the ground. A granular layer is then installed above to remove any ‘hard spots’. Again, this technique does not bring landfill material to the surface. It was trialled in two areas and found to be suitable for use, without causing any effects to leachate levels or ground gases. It is therefore being used as part of the permanent works over the whole site wherever there are not piled structures.

The trials of all three techniques, together with the subsequent site testing proved that the design principles were correct, and gave information on how to refine the solutions further. It also demonstrated that the techniques would not cause any adverse environmental effects.

[caption id="attachment_16142" align="alignnone" width="1200"] (foreground) Ferric mixing and flocculation chambers and (background) concrete bases for sludge tanks - Courtesy of Bam Nuttall Ltd[/caption] Guildford STW: Civils works supply chain - key participants Main contractor: Bam Nuttall Ltd Planning consultant: Adams Hendry Consulting Ltd Civil engineering design: Arcadis Group Ltd Boreholes & testing: Geo-Environmental Services Ltd Asbestos monitoring: Socotec Ltd Rapid impact compaction: Cofra Ltd (Boskalis Group) Vertical rigid inclusions: Foundation Piling Ltd Concrete piling: Aarsleff Ground Engineering Ltd Temporary works specialist: Mabey Hire Ltd Temporary works specialist: MGF Ltd Tunnels & shafts: Joseph Gallagher Ltd In situ concrete works: Kelly Formwork Ltd Precast concrete works: DJ Civils Ltd Precast concrete manufacturer: FLI Precast Solutions Precast concrete manufacturer: A-Consult Ltd Soil processing: Remediation Waste Management Services Concrete supplier: Heidelberg Materials Gas protection: PAGeo Contracting Ltd Crane supply: Delden Cranes Enabling works

Enabling works took place during Spring 2023 and consisted of site clearance, setting up the site offices and welfare and establishing fencing. The whole site was then covered with a 100mm thick layer of imported granular material to provide further protection against the risk of asbestos within the existing capping layer.

A series of 20 further boreholes were installed around the perimeter of the site to enable daily monitoring of both leachate and ground gas within the landfill and to ensure that none was being mobilised by our works. Mobile monitoring stations for noise, dust, vibration and asbestos were all set up, which are monitored continuously throughout the works. Over half a million data points have already been captured.

[caption id="attachment_16138" align="alignnone" width="1200"] Piles and blinding concrete for the four final settlement tanks and (left) temporary ground support for pipelaying into the centre of the tanks - Courtesy of Bam Nuttall Ltd[/caption] Guildford STW: MEICA works supply chain - key participants Main designer/contractor: Enpure Ltd CFD analysis: The Fluid Group Cake silo: Saxlund International PST scrapers & ferric dosing plant: Colloide Inlet works & PST odour covers: Power Plastics Ltd Grit remover plant: Jacopa Escalator screens: Longwood Engineering Imported sludge Strainpress: Huber Technology Sludge thickening & dewatering: Kent Stainless Ltd Odour control plant: Odour Services International Ltd FBDA grids & blowers: Xylem Water Solutions Cloth pile filters: Eliquo Hydrok Ltd Storm tank cleaning system: Sulzer Pumps Wastewater Ltd Tank logging system (WASP): JR Pridham Services Ltd Glass lined steel tanks: Balmoral Tanks Ltd Sludge tank mixing: Landia UK Ltd Groundworks and foundations

The permanent works started in earnest in Summer 2023 and in August, rapid impact compaction was conducted over the site, with a combination of one or two passes, as informed by the results of the previous site trials. In total the ground was hit 360,000 times! Precast piles were then driven for the major structures and pipelines. These were all 250mm square piles and varied in length from 16m to 20m. A total number of 3,422 piles have been driven using three piling rigs.

Vertical rigid inclusion installation is currently underway, with a total of 1,700 out of 9,000 already completed. The works are sequenced to avoid clashes with other work areas, on what is a congested site. Following installation, each work area is left for the piles to cure for the following seven days, thus effectively sterilising large areas of the site at a time. This therefore requires detailed collaborative planning on all work fronts to ensure that the site can remain operational.

[caption id="attachment_16136" align="alignnone" width="1200"] Activated sludge plant precast walls erected, prior to pouring base slab and concrete stitches - Courtesy of Bam Nuttall Ltd[/caption] Concrete structures

Of the 59 concrete structures, some are simple reinforced bases, however ‘the big 5’ are significant structures:

Inlet works. Primary settlement tanks (PSTs). Activated sludge plant (ASPs). Final settlement tanks (FSTs). Tertiary treatment plant (TTP).

Due to the repetitive nature of their construction, BEJV chose to construct the PST and the ASP using precast concrete techniques, which are then stitched together on site. The four FSTs and two storm tanks are also being constructed using precast panels which are then post-tensioned.

The inlet works and TTP are complex, bespoke structures with very little repetition and so are more suited to traditional in situ concrete construction. The inlet works is a particularly complex structure, and is the tallest structure on site at 13m above ground level and being formed of five separate elements.

As of August 2024, the inlet works concrete structure is half complete and the TTP structure underway. The PST precast walls are mostly in place and stitched together, with roof beams now being installed. Works have also started on the ASP walls.

Pipework to the FSTs is underway, which will then allow the construction of the bases to follow on. To date (August 2024), 4,000m3 out 14,000m3 of concrete has been poured, and 205 out of 454 precast wall elements installed.

[caption id="attachment_16141" align="alignnone" width="1200"] (foreground) PST precast walls with concrete stitches and bases and (background) ASP precast walls - Courtesy of Bam Nuttall Ltd[/caption] Transfer tunnel

The flows to the existing STW enter at the southern end of the works. A new transfer tunnel has therefore been constructed to intercept this and transport the flows to the new STW. This tunnel is 1.4km long, 1.5m internal diameter and flows by gravity. It is formed at an invert depth of 10.6m to 15.7m below existing ground level, entirely within the London Clay.

To construct the tunnel a series of six shafts were sunk. The largest of these is 12.5m diameter and forms the inlet shaft in the new STW. The raw sewage will then be pumped from this to the inlet works, from where it will then flow by gravity through the new STW. The remaining five shafts were used to launch or receive the tunnel boring machine (TBM) and pipe-jack, as well as being used for auxiliary connections to sewers in the existing network which don’t get picked up by the main connection.

The tunnel was constructed using the pipe-jacked method using a tunnel boring machine. This was named ‘Daphne’ in a competition by Bisley Church of England School. Daphne Jackson was the first female physics professor in the UK and taught and researched in Guildford. The tunnel consists of four straight sections, one curved section and one short hand-dug section to connect to the existing network.

Current progress is that all of the shafts have been sunk, the main tunnel is complete and fit out the shafts has commenced.

[caption id="attachment_16139" align="alignnone" width="1200"] Safdar Ali, Andrew Dawes and Izhar Ahmad from the BAM team at the completion of the tunnel - Courtesy of Bam Nuttall Ltd[/caption] Outlet

The outlet for the new STW consists of a 750mm diameter pipe from the TTP and a 1050mm diameter pipe which acts as a storm overflow during extreme weather events. These pipes are laid across a floodplain to the River Wey, a distance of approximately 330m before discharging via a bespoke headwall into the River Wey. This has been designed in conjunction with Environment Agency to minimise erosion in what is classified as a salmon river.

Due to Environment Agency and Local Authority permitting requirements as well as practical requirements of working on a floodplain with underlying running sand, these works are practically restricted to a short duration in the summer. This is being undertaken during Summer 2024 and the works are on target for completion within this period.

Below-ground pipework

The majority of underground assets in the new works are being constructed within the existing landfill. This brings plenty of challenges in both design and construction. Assets must be designed to withstand both differential settlement and potential degradation from existing contaminants in the land fill material.

A variety of ductile iron, carbon steel, and concrete pipes are being used with various protection methods. The work is being self- delivered by the BAM workforce and the installation of below-ground pipework is underway with a focus on where it interfaces with the new structures. This requires extensive temporary works solutions to provide a safe working environment for the workforce within the band of landfill material.

Steel sheet piles are being used to provide temporary ground support and excavated landfill material is being sorted in a material handling area on site. This is being done to reduce the amount of hazardous material being sent off site, halving the amount of excavation and disposal required using traditional open cut methods.

[caption id="attachment_16133" align="alignnone" width="1200"] Threading buried process pipework between new structures requires extensive temporary works - Courtesy of Bam Nuttall Ltd[/caption] Integration of existing assets

As well as the main connection taking flows form the existing works to the new, there are three other existing assets which are to be integrated into the new system, at various points along the length of the new tunnel. This involves extensive research and planning in an open and collaborative approach with TWUL networks teams.

Bowers Farm Main was successfully diverted in November 2023, and has been constructed such that the final connection and commissioning to the new system will be a more straightforward operation. Planning works are currently underway on both Stokes Road syphons and Abbotswood syphons in order to construct similar scenarios for future connection and commissioning.

The main connection to the existing Guildford Main at the head of the new scheme entails connecting into an existing 10m deep concrete and brick built chamber, which carries live flows 24/7. The site team have undertaken several successful drawdowns in conjunction with TWUL to ascertain the dimensions and condition of the chamber in order to plan the final breakthrough works in great detail. This design work is currently underway and the new tunnel hand drive has been stopped a few metres short of the final breakthrough and shored up, prior to the final connection to the existing network.

[caption id="attachment_16164" align="alignnone" width="1200"] (left) Concrete bases for the tertiary treatment plant, (top right) cross-sectional view through the primary settlement tank, showing the piles and gas dispersal layer beneath the base, and (bottom right) precast wall panels are joined with an in situ concrete stitch - Courtesy of Bam Nuttall Ltd[/caption] Future works

Construction works of the ‘Big Build’ are continuing at pace and the BEJV Team are now focusing on ensuring a safe, effective and efficient integration of civils and MEICA elements. This will start in late 2024 and continue throughout 2025.

Following successful completion of commissioning of the new sewage treatment works in 2026, the existing works will be de-commissioned making way for the next stage of the Weyside Urban Village, providing homes and leaving a true legacy for local people and businesses.

Project Information Location: Swansea End client: Welsh Water Main contractor: Morgan Sindall Scope of works: Design, manufacture, delivery and installation of the PFET and Blending Chamber structures for Gowerton WwTW Background The reasoning behind the works at Gowerton was a requirement to meet permit conditions in South Wales by 2020. It is a cost-effective approach to challenging flow management at Water Treatment works which enables DCWW to meet their spill permit regulations as laid down by the Welsh Government and Natural Resources Wales. The client was working to an extremely tight programme to achieve consent dates, which meant that the FLI Precast Solutions precast construction methods delivered key advantages over the traditional build process. On completion of the design the precast panels were produced off site at the same time as the 500,000m3 excavation was undertaken to receive the panels. The area was suitably prepared for the delivery of the panels which was coordinated with the site team and the client’s operators to facilitate the existing treatment process. Key drivers for the scheme included the requirement for complex M&E integration which also lends itself to the FLI Precast Solutions design and production philosophy for off-site manufacture. [caption id="" align="alignnone" width="768"] Precast concrete structures under construction - Courtesy of FLI Precast Solutions[/caption] The Gowerton scheme is the first project in the UK to utilise American company WesTech’s Flexfilter technology. Solution Controlled production of elements to a very high standard. Integration of complex M&E systems. Reduced H&S risk on site. Programme savings in the works through a shorter construction programme. Reduced workforce on site resulting in reduced main contractor preliminaries. Reduced construction traffic for the local area, meaning less disruption for residents. Lower carbon footprint as a result of the FLI Precast Solutions construction methodology, which is typically half that of traditional in situ build. Flexibility for programme phasing on site, if necessaryAll units manufactured off-site and called in as dictated by the programme. FLI Precast Solutions provide a secondary sealing system which traditional methods do not offer. Clear works development through Building Information Modelling (BIM) and cutting-edge design capability. [caption id="" align="alignnone" width="768"] Precast concrete structures under construction - Courtesy of FLI Precast Solutions[/caption] A word from our client: Kevin James, Project Manager - Wastewater Infrastructure, Welsh Water Capital Delivery Alliance:

“The scheme involved installing various complex precast structures to house a new flexseal treatment system that will deal with foul water storm flows before discharging to the consented outfall, the first of its kind in Europe. The PFET structure alone was 27m x 26m x 8m deep (at the deepest part), consisting of 3 different levels and various interconnecting chambers.

Due to the high priority of the scheme and the tight deadlines to meet NRW consents, a precast option was progressed. This enabled the design of the structure to be passed to FLI Precast which released our design team to concentrate on other areas of the scheme, showing significant programme savings on the design.

Due to the competency and efficiency of the FLI Precast team the precast installation was completed on time with zero accidents/incidents and to the end client’s satisfaction.”

  For more information: FLI Precast Solutions: +44 (0)1279 423303 | www.fliprecast.com    

The Opportunity Following a number of successful frameworks bids across the water industry, and in preparation for the most challenging AMP ever, we are expanding our high-performing engineering teams across the country. In Newcastle, we are excited to have been appointed as a Strategic Technical Partner by Northumbrian Water for the AMP8 period. Stantec provide a range of technical enabling, solution delivery and design services to support Northumbrian Water in achieving its vision to be the leading provider of sustainable water and wastewater services. As part of our long-standing relationship with Northumbrian Water, including the ongoing ESH-Stantec joint venture, we will continue to develop innovative solutions to support their delivery of capital investment across both infrastructure & non-infrastructure projects. In order to continue providing our clients with our expert service, we are looking to recruit a Senior Civil Engineer into our team Newcastle on the picturesque Quayside. You will become part of an international team, redefining our landscape with sustainability, the environment and the communities we serve at the heart of everything we do. As a Senior Civil Engineer, you will work across the entire project lifecycle in asset planning, strategy, concept design, outline design & detailed design. You’ll be responsible for delivering civil engineering solutions, guided by our Principal Engineers & Design Leads, whilst also supporting & mentoring our more junior engineers.

You can find out more about our work in the water sector here: Stantec H2O+U - UK.

About You We are interested in speaking with passionate engineers with design experience within the UK water industry. You’ll hold a degree in Civil Engineering and ideally have achieved Chartered status with a relevant professional body such as ICE or CIWEM. You will have gained experienced delivering community focused projects, whilst working collaboratively with multi-disciplinary teams to delivery innovative solutions. We will support your growth & development through training & project exposure, though prior experience within storm overflows, SUDS, surface water management & sewage treatment would be beneficial.   About Stantec The Stantec community unites more than 31,000 employees working in over 450 locations across 6 continents. We have been working with our clients and communities in the UK for over 150 years. We plan, design, deliver and manage the development and infrastructure needed to support the creation of sustainable, healthy and prosperous communities.  Our teams provide effective and relevant solutions, translating our clients’ vision into valued consents, deliverable plans for projects and programmes, and efficient designs for delivery, based on technical excellence and deep market insights. We deal with today’s challenges, but also keep a fairer, better tomorrow in sight, looking at how we deliver clean growth, support radical changes in our economy and meet the needs of future communities.  Stantec provides equal employment opportunities to all qualified employees and applicants for future and current employment and prohibit discrimination on the grounds of race, colour, religion, sex, national origin, age, marital status, genetic information, disability, sexual orientation, gender identity or gender expression. We prohibit discrimination in decisions concerning recruitment, hiring, referral, promotion, compensation, fringe benefits, job training, terminations or any other condition of employment. Stantec is in compliance with laws and regulations and ensures equitable opportunities in all aspects of employment. Building an inspired, inclusive work environment that attracts, supports, and develops world-class talent is a crucial key to our success. If you are excited by this role but worry that your experience doesn’t exactly align, we encourage you to apply.

The opportunity Do you have a passion for Civil Engineering ? Are you driven to create solutions for the unprecedented climate, environmental, and efficiency challenges facing our clients and the wider community? Then make a real difference and join us at Stantec! We are excited to continue our growth journey in Ireland and Northern Ireland and we have exciting plans for expansion in 2025 and beyond. We look forward to continuing our work with Uisce Eireann on the Engineering Design Services Framework and in Northern Ireland, we are proud to have been appointed to Northern Ireland Water’s IF182 Professional Services Framework. Taoiseach Simon Harris recently opened our new Dublin office, and we have now also moved to a new city center office in Belfast. This exciting pipeline of work, coupled with the scale of opportunity across the AMP8 cycle in the UK means that we seeking Civil Engineers at all levels with experience in the water/wastewater industry to join us. We are flexible with location so the position can be based in Dublin, Belfast or elsewhere. You will have the opportunity to join a dynamic team spread across the UK and Ireland, supporting the delivery of a variety of projects as part of a major capital investment programme. You will play an important role in the team, developing technical solutions & providing advice to our clients. You will provide technical expertise to ensure projects are delivered to cost, schedule & quality standards and work collaboratively amongst multi-disciplinary teams to ensure first class delivery of our projects.  You will work closely with external stakeholders & clients to develop long term relationships. About You You will be Degree qualified (or equivalent) in Civil Engineering or other relevant subject and have some experience of working within the regulated water industry. You will have knowledge of water and wastewater infrastructure/networks and treatment. Due to the nature of upcoming projects, ideally, you will also have experience in areas such as Clean Water and Wastewater Treatment, Trunk Mains and Large Diameter Pipeline Design. Ideally, you’ll have previous consultancy experience in a design role. Most importantly, you’ll embody our values and ethos of client focus and service excellence and have a passion for making a difference in the Water sector. Why Join us? Our People Culture: We're a close knit team and very proud of our friendly and collaborative environment Growth: We're on an exciting growth journey in Ireland and Northern Ireland - we want you to be part of it! Awards: Stantec were awarded the International Consulting Firm of the Year and Best place to work - Large Consulting Firms at the 2024 NCE awards as well as being consistently recognised in the top 10 Corporate Knights most sustainable companies in the world. Great Benefits: Competitive salary, pension plan, holidays, free private medical insurance, discounted gym membership and lots more. Flexible working arrangements Great Projects: We have secured positions on both the Uisce Eireann and NI Water Frameworks and are delivering a wide variety of projects that will make a real difference to our communities Industry leading training and development as well as paid for professional subscriptions To hear what some of our employees say about life at Stantec, please click on My Stantec Stories.   About Stantec The Stantec community unites more than 31,000 employees working in over 450 locations across 6 continents. We have been working with our clients and communities in the UK for over 150 years. We plan, design, deliver and manage the development and infrastructure needed to support the creation of sustainable, healthy and prosperous communities.  Our teams provide effective and relevant solutions, translating our clients’ vision into valued consents, deliverable plans for projects and programmes, and efficient designs for delivery, based on technical excellence and deep market insights. We deal with today’s challenges, but also keep a fairer, better tomorrow in sight, looking at how we deliver clean growth, support radical changes in our economy and meet the needs of future communities.  Stantec provides equal employment opportunities to all qualified employees and applicants for future and current employment and prohibit discrimination on the grounds of race, colour, religion, sex, national origin, age, marital status, genetic information, disability, sexual orientation, gender identity or gender expression. We prohibit discrimination in decisions concerning recruitment, hiring, referral, promotion, compensation, fringe benefits, job training, terminations or any other condition of employment. Stantec is in compliance with laws and regulations and ensures equitable opportunities in all aspects of employment. Building an inspired, inclusive work environment that attracts, supports, and develops world-class talent is a crucial key to our success. If you are excited by this role but worry that your experience doesn’t exactly align, we encourage you to apply.