Supply Chain - Wastewater Treatment - Preliminary Treatment
- Ballygowan WwTW (2023)
- Hawkchurch STW (2024)
- The Woodlands Water Recycling Centre (2024)
- Macclesfield WwTW (2024)
- Horsham New WwTW (2024)
- Ballina Wastewater Treatment Plant (2024)
- Perth (Bertha Park) WwTW (2024)
- Ards North Wastewater Improvement Scheme (2023)
- Guildford STW (2024)
- Newthorpe STW (2024)
- Ballyronan WwTW (2024)
- Derrycrin WwTW (2024)
- Inlet Enhancement Projects (2024)
- Beckton STW (2023)
- Boherbue Wastewater Treatment Plant (2024)
(left) Existing Ballygowan WwTW - Courtesy of NI Water and (right) demolition in progress: (top) the existing storm tank and (bottom) the existing CAS basin tank - Courtesy of GEDA Construction[/caption]
CAS basins - Courtesy of NI Water[/caption]
New storm tank being utilised during construction - Courtesy of GEDA Construction[/caption]
Ballygowan WwTW under construction (December 2021) - Courtesy of NI Water[/caption]
Interface between new and old works during construction
The majority of the new WwTW works was to be built on a greenfield site which allowed GEDA Construction to build most of the new structures without having to work around existing infrastructure.
However, in order to construct pipelines which would eventually take the flow into the new works, and to construct the new WwTW access road, it was necessary to demolish the existing storm tank in the old works prior to the new works becoming live. GEDA Construction carried these works out by utilising the newly-constructed storm tank and incorporating a carefully developed phasing plan.
A temporary 300mm gravity fed sewer was laid from the existing inlet works to the new storm tank, which in turn rendered the existing storm tank surplus to requirements, as all storm flows had been diverted away from it. GEDA Construction also had to lay a temporary 200mm pumped sewer from the new storm tank complete with temporary pumps to send the storm flows back to the existing pumping station in order for the influent to then go through the treatment process. This in turn allowed us to demolish the existing storm tank and construct the new permanent inlet sewers to the new works ahead of turning flows. This process had to be carefully managed both hydraulically and biologically to ensure the treatment process was optimised and effluent compliance was maintained at all times.
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New permanent high-level sewer under construction - Courtesy of GEDA Construction[/caption]
Turn of flows
Influent flows were successfully diverted into the new works in early May 2022. In order to bring the new biological treatment process online, several tanker loads of seeded sludge were brought to site from another treatment facility and were introduced into the new CAS basin tanks to promote bacteria growth. With flows diverted, and effective treatment established through a rigorous sampling regime, approval was received from NI Water to proceed with the demolition of the remainder of the existing treatment works. Once the existing works were decommissioned and demolished, the entire new WwTW site was able to be finished and access roads completed.
Demolition
Post turn of flows in early May 2022, the existing treatment works was decommissioned and then demolished. Reusable mechanical and electrical assets from the old treatment process were removed for future use by NI Water, while the effluent left in the old CAS basin and pumping station was removed from the site to allow demolition to commence. Effluent was filtered through the new treatment process to minimise unnecessary removal and disposal from site.
CAS basins in operation - Courtesy of NI Water[/caption]
Solmatix Renewables Ltd solar farm - Courtesy of NI Water[/caption]
Ballygowan WwTW nearing completion - Courtesy of NI Water[/caption]
(left) Piling rig set up, (middle) piling reinforcement, and (right) piles cropped - Courtesy of Galliford Try[/caption]
(left) Base shuttered and wall starters, and (right) steelwork for base slab - Courtesy of Galliford Try[/caption]
(left) Jacopa wave screen in the storm tank, (top right) Inlet screen installation in the channel, and (bottom right) inlet screen in action - Courtesy of Galliford Try[/caption]
Rendered 3D model of The Woodlands WRC - Courtesy of EPS Water[/caption]
View of the main MBBR treatment block - Courtesy of EPS Water[/caption]
Noggerath® inlet fine screens at The Woodlands WRC - Courtesy of EPS Water[/caption]
View of the clarifier, sludge thickener & MCC kiosk - Courtesy of EPS Water[/caption]
Chemical dosing plant at The Woodlands WRC - Courtesy of EPS Water[/caption]
Tertiary solids removal plant - Courtesy of EPS Water[/caption]
Inlet works screens - Courtesy of United Utilities[/caption]
Drone image over the MOBTM plant cells - Courtesy of C2V+[/caption]
(left) MOBTM briquettes, (top right) fully developed biofilm on MOBTM media and (bottom right) MOBTM media - Courtesy of Nuvoda[/caption]
Mecana tertiary pile cloth filters - Courtesy of United Utilities[/caption]
MOBTM plant - Courtesy of United Utilities[/caption]
MOBTM plant - Courtesy of United Utilities[/caption]
New inlet screens supplied by Hydro International UK Wastewater Services division - Courtesy of CMDP JV[/caption]
The existing deep bed sand filter is being extended with three additional cells to enhance the tertiary treatment process - Courtesy of CMDP JV[/caption]
The two new Moving Bed Biofilm Reactors (MBBR) to remove ammonia from the final effluent returning to the River Arun - Courtesy of CMDP JV[/caption]
DN900 outlet pipework installed on one of the newly constructed MBBRs - Courtesy of CMDP JV[/caption]
(left) One of the two existing inlet screens being removed, (middle) one of the new 12.8m long Alpha Beta Escalator Screens being lifted carefully into place, and (right) the new inlet screens installed - Courtesy of CMDP JV[/caption]
Inside one of the new MBBRs as its installation approached completion - Courtesy of CMDP JV[/caption]
Setting out for piling works in alkalinity dosing area with sheet piling in place for bank stability - Courtesy of CMDP JV[/caption]
The new MBBR blowers are fitted with acoustic barriers to minimise any possible impact on nearby residential properties - Courtesy of CMDP JV[/caption]
(left) Garry Burgess, CMDP Construction Manager, receiving the award for the efforts of the Horsham New WwTW team and (right) CMDP JV and Southern Water staff pictured volunteering to support local charity, Ten Little Toes - Courtesy of CMDP JV[/caption]
Construction work underway at Ballina - Courtesy of Shay Murtagh Precast[/caption]
New inlet works under construction - Courtesy of Ward & Burke[/caption]
New final settlement tank under construction - Courtesy of Ward & Burke[/caption]
Scope of works (continued)
New storm water tank under construction - Courtesy of Ward & Burke[/caption]
New outfall under construction - Courtesy of Ward & Burke[/caption]
Perth WwTW photographed from Kinnoull Hill Tower in 1971 - Courtesy of Scottish Water[/caption]
MView model showing birds-eye view of proposed design for Perth (Bertha Park) WwTW - Courtesy of ESD JV[/caption]
FST4 under construction - Courtesy of ESD[/caption]
A new distribution system will also be installed. This includes adjustable weirs and flow meters on each outlet to the FSTs. The construction will be staged, incorporating tie-ins to both existing and new pipelines, ultimately ensuring equal distribution among the four FSTs upon completion.
Google Earth image of Perth (Bertha Park) WwTW (2024) - Credit: Google Earth[/caption]
(left) Aeration lanes and (right) well-pointing to aid the construction of FST4 - Courtesy of ESD[/caption]
MView close up of existing FSTs deep tie-ins - Courtesy of ESD[/caption]
Bulk excavation - Courtesy of BSG Civil Engineering Ltd[/caption]
Ards North WwTW - Inlet works overview - Courtesy of BSG Civil Engineering Ltd[/caption]
Inlet works side view - Courtesy of BSG Civil Engineering Ltd[/caption]
Screened raw sewage continues to the grit removal plant. The grit settles in a sump underneath the grit paddle. Any grit that settles in this sump is periodically aerated using the grit blower and then removed. From here the grit is transported out of the grit plant by the grit classifier and is deposited into the grit skip. From here it is removed off site for disposal.
After the wastewater has passed through the grit removal plant, flow continues to the FFT pumping station. Here influent is collected, and FFT of 48.2 l/s (summer) & 29.6 l/s (winter) is pumped to the PST flow splitting chamber.
(left) Ards North WwTW - Courtesy of NI Water, and (right) storm tanks tipping bucket installation - Courtesy of BSG Civil Engineering Ltd[/caption]
Aeration plant air manifold control valves and instrumentation - Courtesy of BSG Civil Engineering Ltd[/caption]
RAS/SAS pumping station - Courtesy of BSG Civil Engineering Ltd[/caption]
The thin sludge tank is equipped with an external mixer for the blending of the tank’s contents to feed the sludge thickening plant. A level ultrasonic with low and high-level floats are used in the control of the mixer.
Mixed sludge from the thin sludge tank is pumped to the sludge thickening plant via the two thickeners feed pumps. These pumps are progressive cavity pumps and are arranged in duty/standby configuration. The pumps are VSD controlled to allow the flow to the thickening plant to be controlled.
There are two sludge thickeners, with an individual throughput of 8.3 m3/hr @ 1.3% DS with a discharge of no more than 6%, based on a 5-hour day, 7-days per week operation at 100% of the maximum design load. The thickeners are arranged in a duty/standby configuration with two actuated isolation valves installed on the feed pipework allow this to be fully automated. If one thickener was to develop a fault, the standby thickener can resume operations without manual intervention.
Polyelectrolyte is made up on site to be added to the sludge fed to the sludge thickening plant. The addition of this chemical aids flocculation and makes thickening easier.
This plant is a liquid polymer set. The liquid poly is delivered within IBCs for the makeup process. The set mixes the poly from the IBC with water to a preset concentration rate and is then transferred to the poly storage tank. The duty poly dosing pump doses to the thickener’s sludge feed pipework from here.
Thickened sludge from the sludge thickening plant is transferred to the thick sludge tank. Here thickened sludge is stored for removal off site. A collection tanker removes the tank’s contents off site by coupling to the tank’s Bauer Coupler connector.
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PST No 1 & control building - Courtesy of BSG Civil Engineering Ltd[/caption]
The tank is equipped with a decant valve arrangement to facilitate settlement of the tank’s contents. The tank is also equipped with a level ultrasonic, low and high-level floats for level status and control of an externally fitted mixer for tank agitation.
The return liquors pumping station receives liquors from the following areas: inlet works drains, thin sludge tank decants and overflow, thick sludge tank decants and overflow, sludge thickening plant bund, FE and washwater drains and odour control plant drains. The station comprises of two fixed speed pumps, which are arranged in duty/standby arrangement. These return liquors to the activated PST splitting chamber.
Low level structures RC concrete installation - Courtesy of BSG Civil Engineering Ltd[/caption]
(left) Ballywhiskin TPS - Courtesy of NI Water, and (right) Carrowdore WwPS - Courtesy of BSG Civil Engineering Ltd[/caption]
(left) Sandycove WwPS and (right) Ballywalter Fowler Way TPS - Courtesy of NI Water[/caption]
NI Water, TetraTech, BSG Civil Engineering Ltd and Farrans along with local elected representatives to mark completion of the £18m Ards North Wastewater Improvement Scheme - Courtesy of NI Water[/caption]
A screenshot of the 3D model used for design and construction - Courtesy of Bam Nuttall Ltd[/caption]
Construction of the high level inlet works structure - Courtesy of Bam Nuttall Ltd[/caption]
(left) Rapid impact compaction underway and (right) a selection of site plant in use - Courtesy of Bam Nuttall Ltd[/caption]
(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.
(foreground) Ferric mixing and flocculation chambers and (background) concrete bases for sludge tanks - Courtesy of Bam Nuttall Ltd[/caption]
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]
Activated sludge plant precast walls erected, prior to pouring base slab and concrete stitches - Courtesy of Bam Nuttall Ltd[/caption]
(foreground) PST precast walls with concrete stitches and bases and (background) ASP precast walls - Courtesy of Bam Nuttall Ltd[/caption]
Safdar Ali, Andrew Dawes and Izhar Ahmad from the BAM team at the completion of the tunnel - Courtesy of Bam Nuttall Ltd[/caption]
Threading buried process pipework between new structures requires extensive temporary works - Courtesy of Bam Nuttall Ltd[/caption]
(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]
Newthorpe STW: (left) site compound and storage, (top) existing site, and (bottom) the new expansion (August 2024) - Courtesy of MMB[/caption]
Heanor flows inlet works (August 2024) - Courtesy of MMB[/caption]
Enhanced Bio Phosphorus Removal UCT configuration - Courtesy of MMB[/caption]
Installation of the tertiary solids removal units (August 2024) - Courtesy of Mott MacDonald Bentley[/caption]
Heanor site overview (September 2024) - Courtesy of MMB[/caption]
Rising main site just outside Newthorpe (August 2024) - Courtesy of MMB[/caption]
Sodium hydroxide (left) and ferric sulphate (right) dosing systems
(left) Existing site on western shores of Lough Neagh, (top right) existing PSTs, and (bottom right) existing percolating filters - Courtesy of NI Water[/caption]
Early excavation works with compound set up - Courtesy of NI Water[/caption]
The contract delivery team worked in a collaborative manner with NI Water, project managers RPS, and key suppliers and subcontractors to deliver a robust, effective and modern treatment solution which allows for future growth in the catchment area and protects the environment by adhering to a tighter discharge consent.
Excavation of FSTs to depth of 5m - Courtesy of NI Water[/caption]
Bottom section of FSTs installed - Courtesy of GEDA Construction[/caption]
Make up of the FSTs from KEE Process - Courtesy of GEDA Construction[/caption]
Installation of RBCs - Courtesy of GEDA Construction[/caption]
Construction of inlet works, sludge tank & storm tank - Courtesy of NI Water[/caption]
Completed Ballyronan WwTW - Courtesy of GEDA[/caption]
The existing Derrycrin WwTW located near the Ballinderry River - Courtesy of NI Water[/caption]
Derrycrin during construction (August 2023) - Courtesy of NI Water[/caption]
Temporary treatment plant used at Derrycrin - Courtesy of DLJ Water Ltd[/caption]
Derrycrin WwTW inlet works - Courtesy of DLJ Water Ltd[/caption]
The new rotating biological contactors - Courtesy of NI Water[/caption]
Flow split chamber - Courtesy of DLJ Water Ltd[/caption]
MCert chamber - Courtesy of DLJ Water Ltd[/caption]
Desludge valves - Courtesy of DLJ Water Ltd[/caption]
NI Water Capital Delivery and Operations personnel pictured with the contract team from DLJ Water and RPS - Courtesy of NI Water[/caption]
The new screen, LISEP and grit trap at Moreleigh STW - Courtesy of Galliford Try[/caption]
Drewsteignton STW screen in foreground and LISEP tucked behind - Courtesy of Galliford Try[/caption]
East Ogwell STW: (left) overall view of inlet and (right) new screen in place - Courtesy of Galliford Try[/caption]
ASP4 South Tank twin wall under construction - Courtesy of Laing O’Rourke[/caption]
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.
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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.
(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.
(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.
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(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]
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.
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New 45m diameter FSTs under construction - Courtesy of Laing O’Rourke[/caption]
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.
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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.
New FSTs with backfilling underway - Courtesy of Laing O’Rourke[/caption]
Google Earth image of Boherbue[/caption]
Inlet works preliminary treatment - Courtesy of Glanua[/caption]
Secondary aeration treatment - Courtesy of Glanua[/caption]
Cloth filter tertiary treatment - Courtesy of Glanua[/caption]
Sludge drying reed beds to process wastewater sludge naturally - Courtesy of Glanua[/caption]
Solar panels for clean, renewable energy - Courtesy of Glanua[/caption]
(left) Precast concrete aeration tanks reduced construction time and safety risks and (right) view of final clarifiers and cloth filters - Courtesy of Glanua[/caption]
Off-site fabrication of steel building, fully assembled as works have been completed (April 2024) - Courtesy of Glanua[/caption]
- HUBER Belt Screen EscaMax®
HUBER Belt Screen EscaMax®Melton Mowbray STW is a medium sized activated sludge works, treating a PE approx. 68,000. The works treats a combination of both domestic and trade effluents. The new Melton Mowbray STW is designed to cater for increased treatment flows equating to a design horizon population equivalent of 123,328 (82% growth) and a tightening of the phosphorus and ammonia permits. A significant proportion of the influent is from trade waste. Huber Technology was heavily involved in the design and planning of the new inlet works with MWH and Severn Trent Water to replace the two existing 6mm screens with three 6mm screens and installation of wash compactors.
Early involvement with MWHT, through site visits and meetings enabled a proven solution to be designed for both screenings and screenings handling requirements. Severn Trent should hopefully see the huge benefit this technology brings to the downstream process very quickly.
Huber was involved in part of the innovative solutions to ensure the re-use of the existing inlet structure in lieu of a new structure. The existing two HUBER screen installation with centre by-pass channel was designed to be replaced by three new HUBER Belt screens EscaMax® and two HUBER Wash Press WAP® L compactors. This was further complicated as the refurbishment had to fit the existing inlet works. This was achieved by the provision of a new bypass pipe outside the inlet works structure and the use of the existing centre bypass channel to house the third screen. Huber worked collaboratively with MWHT to ensure that this was achieved.
[caption id="attachment_16201" align="alignnone" width="1200"]
HUBER Belt Screen EscaMax[/caption]
HUBER Technology supplied
- 2 x HUBER Belt Screen EscaMax® 4000x752/6 60°.
- 1 x HUBER Belt Screen EscaMax® 4000x952/6 60°.
- 2 x HUBER Wash Press WAP® L 8.
- Interconnecting launder.
HUBER Belt Screen EscaMax® Product Profile
-
- World class screening efficiency: 84% average solids capture ratio.
- Unique sealing design ensures continued efficiency with minimal maintenance.
- No requirements for self-adjusting brush due to innovative design.
- Range of perforation sizes & screen installation angles available.
- 300+ installations UK & Ireland.
HUBER WAP®L Wash Press Product Profile
-
- Screenings from launder systems or direct from screens where screen wash water rate is high.
- Wet screenings throughput up to 24m3/hr.
- Volume, weight & disposal cost reduction up to 85%.
- Low power & wash water consumption.
- 600+ installations UK & Ireland.
Details of the process including for screens:
- Total flow rate 548 l/s. Peak flow per screen 183 l/s duty/assist/assist.
- Screen width 752 = 2.85 m3/h and screen width 952 = 3.6m3/h, total capacity 9.3 m3/h all @ 50% blinded.
Details of the process including for screenings handling:
- 9.4 m3/hr duty/standby.
- Screens 0.733 l/s @ 5 Bar. Screening handling Peak 1.5 l/s at 2 bar in operation.
Interconnecting launder[/caption]
Objective & Solution
The main objective was the efficient refurbishment of the inlet works with installation of three new HUBER screens and two HUBER wash compactors on a phased changeover at the inlet. HUBER completed the mechanical installation over three stages with commissioning being completed in stages (in between the install stages) before the next machine was installed as the site needed to have at least one EscaMax® running throughout the installation process.
David Foster McBride (Area Sales Manager) commented on the project:“Early engagement with the customer allowed for a suitable innovative solution to be selected to handle the design parameters and be successfully delivered within the existing inlet works limitations. The project was delivered on time and to budget and is an excellent demonstration of close involvement with Severn Trent Water and MWHT.”
For more information: Huber Technology | +441249 765000 | www.huber.co.uk
- Greenham Common STW
Greenham Common STWThames Water’s Greenham Common Sewage Treatment Works (STW) is situated in the shadow of a former US Air Force base in Bishops Green, Newbury, and alongside the River Enborne. The untreated wastewater that Greenham Common receives has a high rag content and repeated screening carry over was affecting the full treatment process, the overall performance of the site and risked that the site would go out of environmental compliance. Thames Water approached Hydro International’s UK Wastewater Services team, M&N, to evaluate the site and propose a robust solution. The team installed the MNSS Combined Screen, to capture larger influent materials at the front end of the wastewater treatment process, protecting and improving the efficiency of the downstream treatment system. Due to the site hydraulics/flows, there was no reliable wash water system for the MNSS Combined Screen, so the team found an innovative way to solve this. They created a bespoke system, including pumps, to use the effluent from the site’s primary settlement tank. The spray nozzles on the MNSS Combined Screen were also altered to accommodate the change. [caption id="" align="alignnone" width="1200"]
Greenham Common STW MNSS Combined Screen[/caption]
Simon Brum, Project Manager, Hydro International’s UK Wastewater Services Team, said:
"We needed to find a quick and effective solution for the Greenham Common STW to prevent any overflows, and designed and installed a robust, reliable inlet works system that combines screening, washing, transport, compaction and dewatering in a single cost-effective standalone solution.”
Henry Crompton, Lead Project Engineer at Thames Water Utilities Ltd, commented:“We needed a suitable solution that was effective and within budget, and the team delivered that. We are very happy with the work undertaken on this site and will be using it as an example to our other Thames Water teams who may encounter the same issues.”
Handling flows of up to 150 l/s, the MNSS Combined Screen is designed for smaller plants and those facilities that require a more cost-effective screening solution - helping engineers, operators, and site owners to maintain treatment effectiveness even at remote and budget - constrained sites. [caption id="" align="alignnone" width="1200"]
Greenham Common STW MNSS Combined Screen[/caption]
Optimised for reduced maintenance and extended component lifetimes by the UK Wastewater Services team, only the MNSS Combined Screen achieves a screenings capture ratio of 53%, the highest of any independently tested 6mm combined screen.
To learn more about how our inlet works specialists can help you with your wastewater needs
M&N Electrical & Mechanical Services Ltd | +44 (0)1305 821142 | www.hydro-int.com/ukwws
- Carbarns WwTW
Carbarns WwTWCarbarns Wastewater Treatment Works (WwTW) is located in Wishaw, to the South-East of Glasgow, within the Clyde River valley. The site is part of the ‘Clyde 7’ group of Scottish Water treatment facilities, serving a population of over 54,000 from Wishaw and Overtown areas. Along with the inlet works, the site has primary and secondary treatment and phosphorous removal. Treated water from the plant is discharged into the River Clyde. The 6mm fine inlet screens at Carbarns WwTW were failing regularly as the screen panels were plastic and very prone to breaking, particularly following storm events when flows were higher than usual and contained more debris. Scottish Water was having to stock spare panels on site and replace them as often as every week, depending on the weather. When the inlet screens failed, a considerable amount of rag was feeding through to the primary settlement tanks, causing chokes in the sludge pumps. When the screens tripped out in storm conditions the bypass screen would blind up in minutes, not allowing enough time for standby operators to reach the site, and causing flooding at a nearby property. The result was a significant amount of time and resources spent on clearing these chokes and blockages and cleaning up by the operations team. The biggest impact of this inlet issue was the financial and carbon implications. Carbarns WwTW would normally send sewage sludge directly to the Daldowie fuel plant, near Glasgow, which processes it into a renewable, low carbon form of biomass fuel pellet. However, because of the high content of rag in the sludge caused by the inlet screen failures, it could not be sent directly to Daldowie Fuel Plant but had to be taken for further processing to Shieldhall WwTW, some 20 miles away on the other side of Glasgow. This involved up to 23 tankers a week transporting the sludge to Shieldhall for additional treatment, before it could be pumped over to Daldowie. The associated costs of transporting the sludge to Shieldhall WwTW were considerable. [caption id="" align="alignnone" width="1200"]
Carbarns WwTW inlet works screens[/caption]
Scottish Water worked with Hydro International’s UK Wastewater Services team, M&N, to evaluate the site and propose a solution. The team installed a Kuhn KHU-S Multirake Boomerang 70mm coarse screen to provide protection to the FSM escalator screens by removing the larger coarse screenings. Two FSM FRS 111 escalator screens were then fitted at 60°, providing an impressive maximum flow capacity of 770 l/s each, to provide fine screening of the sewage inflow.
The screens are running in a duty standby mode, conducted automatically by the control panels which were supplied for all equipment. Each of the screens has capacity to take the full flow to treatment, should one need to be taken off-line for service, maintenance, or repair. The strong screen panels are stainless steel so able to withstand storm flows, combatting the initial issue of weak plastic-based material screens. A launder system was installed to transport rag to two Kuhn KWP-HD 400/1200 wash presses to process, wash and compact the rags.
Once the new inlet works package was installed, the primary settlement tanks and aeration tanks were cleaned to ensure that no rag was left in the system. This was an additional cost of £106K before Daldowrie Fuel Plant could accept the sludge again.
Simon Light, National Sales Manager for Hydro International, said:
“We needed to find a high-quality effective solution for the Carbarns WwTW to prevent any further overflows, and to help reduce the high cost and carbon impact the high content of rag in the sludge was creating. Our specialist inlet works team designed and installed a robust, reliable inlet works system that combines screening, washing, transport, compaction and dewatering in a single cost-effective and sustainable standalone solution.”
Stephen Heatley, WW Operations Team Leader at Scottish Water, comments:“Knowing the team for over 20 years, we were confident that they would provide a solution that works exceptionally to meet our needs. Since the project’s completion in September 2020, there has been a significant reduction in costs and carbon use now that the sludge can be transported directly to Daldowie Fuel Plant for processing. The amount of reactive time that operation staff previously needed to spend dealing with chokes and cleaning up has dramatically reduced, with a knock-on effect that morale has improved, providing more time to spend on proactive tasks.”
Moving forward, the UK Wastewater Services team will service the screens every year and provide maintenance to ensure the equipment is operating at optimum performance.
To learn more about how our inlet works specialists can help you with your wastewater needs
M&N Electrical & mechanical Services Ltd | +44 (0)1305 821142 | www.hydro-int.com/ukwws
- Ground-breaking project leads to advanced wastewater grit removal system
Ground-breaking project leads to adv...Suspended solids carried in water can cause a range of harmful effects in rivers, lakes and oceans, making the capture and removal of these solids critical for effective environmental protection. To address this problem, the project focused on optimising the stacked trays that remove high levels of suspended solids from wastewater. Combining optimisation methods and computational fluid dynamics (CFD), the project was able to derive new designs for hydrodynamic solids removal components that would have been difficult or impossible to achieve using traditional engineering methods. The research was part of a Knowledge Transfer Partnership (KTP), supported by the UK government’s innovation body Innovate UK, which began in July 2019 and ran until September 2021. It builds on years of collaboration between Hydro International and the University of Exeter in the field of CFD. The core of the project involved the optimisation of stacked trays that enable the removal of high levels of suspended solids in wastewater, with the primary objectives being to improve performance and reduce maintenance requirements. This was a complex, multi-objective, high-dimensional problem, so the team needed to adopt an unconventional approach in order to solve it. To tackle the problem the project team coupled Bayesian optimisation techniques and CFD modelling, using a Bayesian optimisation toolset originally developed by the world-renowned Machine Learning Group at the University of Exeter. Bayesian optimisation was selected as it can be an order of magnitude more efficient than alternative approaches, such as genetic algorithms, on such complex design problems. The Bayesian optimisation toolset was then connected to CFD simulations, allowing the team to use computing power to automate the design and evaluation process. The team ran the CFD simulations using supercomputers in Exeter and Bristol, with each optimisation run modelling some 300 designs at a time. This would have been impossible to achieve using other optimisation techniques. The team was one of the first in the world to use these techniques on new GW4 Isambard super-computing architectures. The team subsequently corroborated simulation results through physical testing of prototypes in Hydro International’s hydraulics laboratory in Clevedon. The outcome of the project was a new stacked tray design that improves grit removal performance and enables the production of more compact systems that can handle higher wastewater flows and requires less maintenance—an excellent example of combining academic research with commercial incentives to address real-world challenges. Although the project was focused on improving technologies that will be applied to future iterations of the HeadCell® advanced grit removal system, the findings are fundamental to Hydro International’s core technologies, and will be applicable to other products that rely on the same hydrodynamic principles such as Downstream Defender® and First Defense®. In addition, not only did the project apply methods for complex design optimisation already developed by the University of Exeter, but it also drove new developments in multi-objective optimisation and constraint handling, resulting in new advances in expertise and understanding. Following completion of the project, Innovate UK assessed the KTP and awarded it a Grade A, or “Outstanding”. Dan Jarman, Hydro International’s Group Technical Manager said:“We have a long history of investing in new science and new technologies to help our customers, and this project continues that tradition. This is the first time that Bayesian optimisation and CFD techniques have been applied in the water sector, which represents a significant step forward in product design excellence. In a sector that has been unfairly criticised for being slow to adopt new technologies and techniques, we’ve shown that there are teams out there willing to push boundaries in order to benefit utilities, consumers and the environment.”
Jonathan Fieldsend, Professor in Computational Intelligence at the University of Exeter said:“This project is an excellent example of what can be achieved when a KTP involves such a wide range of talent and experience. To achieve its outcome, it has needed academics from the Computer Science and Engineering departments, specialists from industry, and support from a highly-skilled impact and business team. It has delivered significant enhancements for an important Hydro International product - in the crucial area of wastewater management - and has also led to advances in applied optimisation techniques and algorithms which have use more broadly in CFD-driven design.”
About Hydro International
Hydro International is a global company that provides advanced products, services and expertise to help municipal, industrial and construction customers to improve their water management processes, increase operational performance and reduce environmental impact. With over 40 years of experience and a reputation for engineering excellence, businesses and public organisations all over the world rely on Hydro International products and services to reduce flood risk, improve water treatment and protect the environment from water pollution. Headquartered in Clevedon, UK, Hydro International has a network of over 80 distribution partners and serves customers in more than 40 countries.About the University of Exeter
The University of Exeter combines world-class research with excellent student satisfaction, ranking in the Top 150 of the THE and QS World University Rankings. We are one of the very few universities to be both a member of the Russell Group and have a Gold award from the Teaching Excellence Framework (TEF), evidencing our international reputation for excellence in teaching and research. Each year, the University of Exeter delivers over 1500 projects with industry and generates over £52m from this work. We believe impact is about making a difference, and our world-class researchers have an excellent track record in making valuable contributions to our society, economy and the environment. Our dedicated KTP team - based at the University’s Innovation, Impact and Business directorate - is the leading Knowledge Base partner in South West England and has successfully delivered over 100 KTP projects to date, with 85% of these rated good to outstanding.
To learn more about how our inlet works specialists can help you with your wastewater needs
M&N Electrical & mechanical Services Ltd | +44 (0)1305 821142 | www.hydro-int.com/ukwws
- Grit Removal Travelling Bridges at Beckton STW
Grit Removal Travelling Bridges at B...The project scope includes:- 3 (No.) travelling bridges (57 m long) supplied by SAVECO Environmental Limited
- 3 (No.) rotary lobe pumps supplied by Boerger LLC
- 3 (No.) level probes supplied by VEGA Level and Pressure
- 3 (No.) PLC control panels supplied by Te-Tech Process Solutions
How they work
PVD grease and grit removal travelling bridges are used to remove grease and grit from rectangular tanks in both municipal and industrial wastewater treatment plants. The travelling ridges consist of a movable truck lying on two traction trolleys. One surface scraper and one bottom scraper are installed underneath the truck. The bridge is operated by a central gearbox connected to trolley drive wheels. The tank is divided in two main parts: one for grit settling, the other one for grease collection. An air injection system installed inside the grit channel generates a circular movement, thus separating organic and floating particles from the grit. By this movement scum is conveyed into the grease collecting channel, while grit continues to settle. The bridge travels back and forth. Travelling one way, it conveys the settled grit into the grit collection hopper through the bottom scraper. Running in the opposite direction it collects scum and floating particles by means of a surface scraper. The scrapers are operated by one gear motor only. [caption id="" align="alignnone" width="1200"]
Courtesy of SAVECO Environmental Limited[/caption]
Features
- Available for up to 8m wide and 50m long tanks
- Grit removal device
- Scum removal device
- Festooned cables
- Control panel
- Hot dip-galvanised carbon steel / 304 L / 316 L SS
- Quick installation
- High efficiency grit and grease removal
- Easy installation even into existing tanks
- Cable holding chain
Courtesy of SAVECO Environmental Limited[/caption]
For more information contact SAVECO Environmental Ltd | +44 (0)1684 299104 | https://saveco-water.co.uk
