Supply Chain - Sewerage
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Related Content
Case Studies
- Ards North Wastewater Improvement Scheme (2023)
- Marchmont Road Flood Alleviation Scheme (2024)
- Stroud Sewerage Strategy Project: Part 2 (2023)
- Saltcoats Rising Main (2024)
- Arklow Long Sea Outfall (2023)
- St Augustines Road Flood Alleviation (2023)
- Guildford STW (2024)
- Newthorpe STW (2023)
- Galmpton Catchment (2024)
- Grays Sewer Rehabilitation (2024)
- Norton, Presteigne & Weobley WwTWs (2023)
- Event Duration Monitoring Programme (2024)
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]
Google Maps image showing location of the site[/caption]
Storm tank under construction - Courtesy of Paul Milligan & CWA[/caption]
Marchmont FAS project site - Courtesy of Paul Milligan & CWA[/caption]
Storm tank roof installation - Courtesy of Paul Milligan & Caledonia Water Alliance[/caption]
Customer information event - Courtesy of Scottish Water[/caption]
(left) The launch of TBM Marvellous Mining Molly and (right) shaft with pipe jacks installed about to be benched - Courtesy of Galliford Try[/caption]
Due to varying local topography and numerous obstacles along the route the team opted for a combination of open cut and pipe jack tunnelling techniques for the trunk sewer - details below.
TBM Marvellous Mining Molly in position to start mining - Courtesy of Galliford Try[/caption]
(left) Installation of prefabricated chamber within live sewer line and (right) inside the prefabricated chamber - Courtesy of Galliford Try[/caption]
Construction of bypass channel and (inset) installation of the temporay PortaDam from OnSite Central Ltd - Courtesy of Galliford Try[/caption]
(left) Excavation of shaft and (right) preparations for open cut rising main installation - Courtesy of Galliford Try[/caption]
(left) Aerial view of the project and (right) rising main failure - Courtesy of Caledonia Water Alliance[/caption]
Pipe delivery - Courtesy of Caledonia Water Alliance[/caption]
Assembly of overhead pipe bridge - Courtesy of Caledonia Water Alliance[/caption]
Bypass pit showing pipework cut out and a new ‘T’ piece and valve arrangement - Courtesy of Caledonia Water Alliance[/caption]
Liner installation - Courtesy of Caledonia Water Alliance[/caption]
Drone image showing the scaffold tower and the liner installation operation underway - Courtesy of Paul Milligan, Caledonia Water Alliance[/caption]
CCTV output pre and post lining - Courtesy of Caledonia Water Alliance[/caption]
Outfall pipe arrival from Norway by sea to the dock in Arklow for preparation and assembly - Courtesy of Van Oord Ireland[/caption]
The proposed outfall pipeline was required to discharge the treated effluent from the wastewater treatment plant to receiving waters. Both marine and river outfall options were initially considered for the proposed development.
However, hydrodynamic and water quality modelling demonstrated that the wastewater discharge standards required for a river outfall would be much more onerous than that of a marine outfall. For that reason, the river outfall was not considered further.
Outfall pipe floated along the quay wall in Arklow prior to preparation and assembly works - Courtesy of Pipelife Norge AS[/caption]
The marine outfall was also designed to be stable in the ‘worst case’ design loads for current and wave loading conditions provided. It was therefore necessary to weight the pipeline with concrete collars and subsequently concrete kennels after installation (float and flood method), to provide a specific gravity of not less than 1.35 that could be achieved without any reliance on backfill material.
This installation weight was provided with 1015kg (290kg/m) (in air) fixed weight concrete collars at 3.5m centres and to satisfy the permanent on bottom stability, 2292kg (654.86kg/m) (in air) concrete kennels were provided at 3.5m centres in between the fixed weight concrete collars. The collars and kennels were provided by Tracey Concrete.
Welding of risers for diffuser section of outfall pipe - Courtesy of Van Oord Ireland[/caption]
Excavation of trench at the onshore connection point using the backhoe dredger ‘Razende Bol’ - Courtesy of Van Oord Ireland[/caption]
(left) Outfall pipe during sinking operation and (right) outfall pipe aligned prior to sinking operation - Courtesy of Van Oord Ireland[/caption]
Outfall pipe concrete collars being fitted in water with special lifting equipment - Courtesy of Van Oord Ireland[/caption]
Once the outfall pipeline had been sunk to the sea bottom and pressure tested, concrete kennels, each weighing 1 tonne were placed in between the concrete collars at 3.5m centre to centre spacings to provide additional permanent weighting. Additionally, six diffusers were installed from the backhoe dredger platform by divers. Each diffuser comprised of a flanged PE pipe, fittings and a riser with a four-port crosshead, each with a flange allowing for Tideflex S35 valves to be fitted directly. Included as part of the diffuser installation, was a removable access flange at the top of the riser to enable access inside the riser.
After completing the diffuser and kennel installation, the pipe was backfilled over its full length to provide 1.5m cover. Rock armour protection was further provided extending approximately 7m around the diffuser section from its centre to protect the area around the diffuser from scour. Also provided was a steel protection frame for the diffuser, fitted with sacrificial anodes to allow a 50yr design life for protection from dropped objects, anchors, trawlers and fishing nets. Finally, on the offshore end a marker buoy and on the onshore end a Saint Andrews Cross were installed to mark the pipeline location.
Due to the turbulent weather at the site location, including hold points in the working method, so that each installation step could be paused at planned intervals, allowed Van Oord to work around the weather. Additionally, working with local contractors who helped to adjust and adapt work methods and techniques within the limited amount of space, allowed the team to prepare and install the outfall system using specialised equipment and marine vessels, with minimal disruption to the environment and public. In particular, a bespoke rigging system was designed and fabricated using a local yard to assist with the efficient installation of the collars whilst working from the water.
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Outfall pipe during sinking operation - Courtesy of Van Oord Ireland[/caption]
(left) The preferred option and (right) flooding on St Augustines Road - Courtesy of Galliford Try[/caption]
Outfall under construction - Courtesy of Galliford Try[/caption]
Poor ground and underfoot conditions adjacent to the River Rother proved too risky and problematic for traditional mobile crane lifts, so all lifts of the precast sections were to be undertaken with a tracked excavator. This further constrained the design and restricted the maximum mass of each section to 13 tonnes. Consequently, in its final iteration the precast headwall was designed in two sections and was combined with an in situ toe and infill slab/wall which completed the structural design.
(left) Installation of drive pit on St Augustines Road, (middle) guided auger bore rig, and (right) the transition between 600mm and culverts - Courtesy of Galliford Try[/caption]
Settlement calculations were undertaken using the “Guide to best practice for the installation of pipe jacks and microtunnels technique” and a predicted settlement of <3mm was deemed to be acceptable. The pre-condition surveys highlighted only minor cosmetic issues and were used as reference to the state of repair of the properties prior to construction work commencing.
The majority of the civil design was undertaken in house. This element included a design coordination role combining and processing the information received from the consultants and stakeholders. An example of the numerous stakeholders which were consulted is that of the Coal Authority. Initial searches indicated the presence of historical coal workings. More detail was sought and records indicated the presence of an adit within 20m of the proposed pipeline. A coal permit was sought from the Coal Authority and the design progressed whilst this was processed.
Service detection - Courtesy of Galliford Try[/caption]
Cofferdam and silt curtain - Courtesy of Galliford Try[/caption]
Cofferdam
A cofferdam was required to retain the River Rother and this was designed and supplied by National Trench Safety UK and installed by the primary subcontractor Arthur Civil Engineering. The cofferdam was unique in design in that it utilised Larsson piles in a trapezium shape (plan) to minimise over-dig yet still accommodate the headwall and first culvert.
The cofferdam was installed by Ivor King Piling using a 35t excavator with a Movax side grip pile driver attachment. The cofferdam was effective but 4” end suction pumps supplied by Selwood Ltd were still required to maintain the cofferdam and keep water levels low.
Headwall installation
Once the cofferdam was watertight, the headwall toe was cast in situ, after which the precast headwall arrived in two sections as planned. It was lifted into position by Arthur Civil Engineering using a 50t tracked excavator. An administrative issue led to the need to negotiate a 2-week FRAP extension with the EA and the headwall was completed and the cofferdam removed by 14 October in accordance with the conditions of the revised FRAP.
Pipeline works
Construction works on the remainder of the project continued in March 2022. A temporary one-way system was implemented to provide a safe working area to install the remainder of the pipeline with open cut works commencing on 14 March. The open cut works progressed steadily with over 100 services safely crossed. The later spring and summer months provided excellent conditions for online sewer relay with drought-like conditions, culminating in hosepipe bans for the majority of the UK.
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Open cut pipelaying - Courtesy of Galliford Try[/caption]
Prior to the tunnelling works commencing, concern was raised over the proximity of the tunnel as it crossed under a 225mm foul water sewer in Derby Road. With a clearance of just 300mm, the existing foul sewer was inspected by CPS Drainage Solutions using CCTV and a precautionary 5m cured-in-place patch liner was installed to strengthen the sewer prior to the guided auger bore operation. No-dig works commenced in early June and progressed well without incident and were completed towards the end of the summer. No settlement was detected during the installation and no visual deformations were reported from the nearby structures.
Open cut works continued late into the summer with flooding benefits delivered by 5 October. Significant rainfall events have since occurred and the feedback from residents previously affected by the flooding has been positive.
900mm Ridgistorm pipe from Polypipe Civils ready for installation - Courtesy of Galliford Try[/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]
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 Revit model - Courtesy of MMB[/caption]
Anaerobic & anoxic tank construction progress - (July 2023) - Courtesy of Mott MacDonald Bentley[/caption]
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.
ASP Tank construction (July 2023) - Courtesy of Mott MacDonald Bentley[/caption]
(left) Ground modelling to explore coal seams and (right) detail of rising main welding area - Courtesy of Mott MacDonald Bentley[/caption]
Aerial shot showing Galmpton STW on the right and rising main scar through the fields on the left - Courtesy of Galliford Try[/caption]
Galmpton stormwater storage tank following the installation of the flushing bell and air valve release pipework - Courtesy of[/caption]
Storm tank roof installation main beam lift - Courtesy of Galliford Try[/caption]
Galmpton storm tank with the precast concrete roof installed - Courtesy of Galliford Try[/caption]
Overpumping pipework - Courtesy of @one Alliance[/caption]
Vanderkamp UK’s temporary overpuming pipework while OnSite Cental undertake the CIPP lining works - Courtesy of @one Alliance[/caption]
OnSite Central’s CIPP lining operation - Courtesy of @one Alliance[/caption]
Traffic management during the works - Courtesy of @one Alliance[/caption]
Customer information boards - Courtesy of @one Alliance[/caption]
Norton SPS progressive cavity pumps - Courtesy of Morgan Sindall Infrastructure[/caption]
Norton SPS: MCC kiosk and Haigh Engineering inlet screen - Courtesy of Morgan Sindall Infrastructure[/caption]
Spider plough operation to construct the Norton WwTW pump away rising main - Courtesy of Morgan Sindall Infrastructure[/caption]
Presteigne WwTW: Ferric point of application (PoA) unit - Courtesy of Morgan Sindall Infrastructure[/caption]
Alkalinity dosing was required as a result of the new ferric dosing. The identified solution for this was a small bag dosing plant with on-site mixing to create a liquid dose. A new point of application facility located on the side of the existing PST which discharges to the biological filter. It was determined that this point had enough hydraulic mixing for an effective alkalinity dose.
The new works is achieving its ammonia consent with the current loading, but it had been identified that ammonia compliance could be a risk during AMP9. Nitrifying sand filters have been proposed as a technology to treat the ammoniacal nitrogen as a tertiary treatment solution. This has an added benefit of tertiary solids removal to give confidence in the total phosphorus consent. However, given the excellent performance of the works against consent and nitrifying capacity of the existing biofilters, the nitrifying sand filters will be phased into the works when required.
Works included a new sampling arrangement with sampling kiosk, complete with an upstream diversion and reception chamber for when the nitrifying sand filter is constructed.
Presteigne WwTW: Ferric dosing system and safety shower - Courtesy of Morgan Sindall Infrastructure[/caption]
Weobley WwTW: (left) Huber Technology inlet screen and (right) flow to full treatment pump station - Courtesy of Morgan Sindall Infrastructure[/caption]
This provided significant cost and embodied carbon savings compared to a completely new screening installation. Downstream of the screen, an inlet flume was provided for flow measurement and control of the downstream lift pumping station. The flume was constructed off-site, allowing for greater dimensional accuracy than an on-site constructed flume, as well as reduced downtime for the site.
A new lift pumping station for all incoming flows for treatment was required to provide a separate lift to the balancing tanks then the unscreened storm flows. The existing inlet pumping station was re-purposed as the storm pumping station, meaning the more efficient pumping station was operating for more of the time compared to the older storm pumping station, which only operated intermittently - hence saving on energy usage and operational carbon.
An existing multi-use returns pumping station was used to pump humus returns and storm returns to the head of the works. This asset consisted of outdated and poorly operating pumps and valve work. A solution was developed to replace mechanical equipment within the existing dry-well, saving the need for a new complete pumping station.
Weobley WwTW: Ferric point of application units - Courtesy of Morgan Sindall Infrastructure[/caption]
(left) New ultrasonic head in existing tank and (right) new ultrasonic head at existing spill point - Courtesy of Galliford Try[/caption]
New level controller - Courtesy of Galliford Try[/caption]
Innovations
- Detecting Hydrocarbon Contamination (2023)
Detecting Hydrocarbon Contamination ...A municipal wastewater treatment plant in Poland was struggling with a persistent issue; hydrocarbon contamination in the wastewater coming into the plant. The plant had not been designed to deal with high levels of hydrocarbon contamination, such as that coming from untreated industrial wastewater, which meant that every time there was a contamination event in the sewerage system, the WwTP performance was affected and, in the worst case, contamination was also released into the environment and regulations were broken. Moreover, the activated sludge performance was affected and, if the levels were high enough, this could lead to the process needing to be stopped altogether.The solution
In the spring of 2022, Multisensor Systems Ltd’s Polish distributor (GREMES) was contacted to review options and following preliminary discussions, engineers at GREMES proposed an MS1800 VOC gas analyser to be installed directly above the sewage line. The MS1800 is designed to monitor VOC concentration in the headspace above the wastewater and from this, calculate the hydrocarbon contamination within the wastewater. [caption id="" align="alignnone" width="1200"]
Installation diagram - Courtesy of Multisensor Systems Ltd[/caption]
The instrument was installed in a temperature controlled cabinet, ensuring that the analyser’s technical specifications were met in the open air. The system was linked to a remote control system to provide a live data feed and allow the user to generate reports and alarms.
The site selected for the installation is a wastewater pumping station, the last before the intake of the WwTP. This has made the installation more straightforward and, with a constant flow of wastewater, reduced the risk of H2S build-up that could be detrimental to the longevity of the system.
The data
The instrument was installed in July 2022 and, aside from a brief pause, has (at the time of writing - April 2023) been working non-stop ever since. The data below shows how the instrument has clearly identified several peaks over the course of several months. These peaks have been positively associated with contamination events and corroborated by analysis carried out by the WwTP. After several months of testing the client is extremely satisfied with the results and is in active discussions with GREMES to develop the next phase of the project that will consist in deploying a network of analysers across strategic points in the sewerage network. [caption id="" align="alignnone" width="1200"]
Graph showing hydrocarbon readings from September 1, 2022-March 1, 2023 (graph produced by independent software) - Courtesy of Multisensor Systems Ltd[/caption]
Uses
The MS1800 in this installation will be mainly used to identify contamination events and locate the source of pollution but also to protect the WwTP by diverting industrial wastewater for separate treatment.Strengths
This system allows the accurate on-line monitoring of hydrocarbon contamination in the sewage system, without touching the water, designing out of the equation words such as 'cleaning', 'maintenance' and 'filtering'.Conclusion
As can be seen from the data above, the MS1800 is an excellent solution for the monitoring of hydrocarbon contamination in any sewerage network. If your operations are suffering from unexpected hydrocarbon contamination at the raw wastewater intake of your WwTP, you can get in touch and discuss your case with our consultants.
This article was prepared by Multisensor Systems Ltd Alexandra Court | Carrs Road | Cheadle | SK8 2JY P: +44 (0)161 491 5600 | E: [email protected] | www.multisensor.co.uk
Mini CS & Company News
- Thames Tideway Tunnel - West Section
Thames Tideway Tunnel - West SectionThe waterproofing challenge
Thames Tideway is London’s new “super sewer” which will run from Acton to Beckton and prevent millions of tonnes of pollution reaching the River Thames. The West Section is being It is constructed by the joint venture between BAM, Morgan Sindall and Balfour Beatty. During the design phase, technical discussions were held between SMR Projects and the JV designers Morgan Sindall Underground Professional Services to explore how Xypex’s crystalline technology could assist in reducing the permeability of the concrete. This was especially important across the construction joints. Trials were undertaken in conjunction with a ready mix company to establish how the crystalline technology behaved within the very specific mix design. In addition this was to prove its water tightness over standard tunnel construction methods. A number of trials were set up with and without Xypex products for a clear comparison.Successful trials
The trial results proved that the addition of Xypex C-Series Admix to the concrete gave the greatest protection against permeability. The growth of the crystals across the joint gave a seal in excess of what was thought possible. When tested across the 45 degree “day” joint, cores were taken through the joint in 3 axis to test for water permeability and the results were more than enough to confirm that this technology was superior. [caption id="" align="alignnone" width="1200"]
Courtesy of SMR Projects Ltd - Xypex UK Distributors[/caption]
Change of design
The western section was originally planned to be constructed using a sprayed concrete primary liner and a cast in situ secondary liner with a waterproof membrane placed in between the two layers. The addition of Xypex C-Series Admix meant that, following the trials, the stakeholders were satisfied enough to remove the membrane in the Hammersmith connection tunnel. The proven benefits of using Xypex C-Series Admix lead to its use throughout the whole of the Western Section.Added benefits of Xypex
The Xypex C-Series Admix waterproofed the concrete and the joints during the hydration period of the concrete. It also provided additional benefits over and above non-active pore blocking admixtures by having the ability of self-heal cracks up to 0.4mm. Furthermore, microbial induced corrosion is common to sewage collection and wastewater treatment structures. It’s a challenge well known to engineers as they address the ever-increasing requirement for structures that will meet the growing demands of industry, the environment, economics, and the need for improved water supply and sanitation. Xypex is proven in new sewage and wastewater treatment structures. It is excellent at handling chemical attack in severe biochemical conditions. [caption id="" align="alignnone" width="1200"]
The Xypex solution; Xypex C-Series Admix - Courtesy of SMR Projects Ltd - Xypex UK Distributors[/caption]
The final specification
SMR Projects supplied 100,000 kilograms of Xypex C-Series Admix. This was used on the primary liner incorporated within the sprayed concrete, awaiting the secondary liner to be cast directly against it.
For more information: SMR Projects Ltd - XYPEX UK Distributors: +44 (0)1295 279747 | www.smrxypex.co.uk
- Circular Pipe Mounted Gratings
Circular Pipe Mounted GratingsAlthon circular pipe mounted gratings are manufactured as standard in galvanised mild steel for pipe diameters from 300mm up to 1500mm. Designed to be mounted inside the opening of the pipe, they are ideal for bagwork or vegetated headwalls and made to suit your pipe diameter.
Pipe mounted gratings are hot dip galvanised to BS EN 1461 after fabrication as standard, but they can also be manufactured in stainless steel on request. The gratings in the photos have been installed at a Wildlife Park in Suffolk. Hoping for some animals in the photos next time, so stay tuned!
For more information please contact our sales team by emailing [email protected] or call us on 01603 488700
- East Budleigh Culvert Re-lining
East Budleigh Culvert Re-liningEast Budleigh is a small village in East Devon, UK located about 2 miles (3.2km) north of Budleigh Salterton. The village features a bypass culvert, constructed in the 1970s. The culvert is approximately 280 metres in length, of Armco construction, oval shaped and constructed from corrugated metal sheeting (with a concrete floor laid over it during the last 10 years). The existing culvert was in a poor condition, with joints failing and large voids appearing in the material outside the culvert structure. These failures led to a small localised collapse in the road above during flooding in 2012 and there were concerns that in the future that a larger collapse could occur, causing a failure in the highway surface. It was decided that this culvert required structural strengthening due to minimal cover to the busy road above, and to maintain flows through the culvert in storm conditions. [caption id="" align="alignnone" width="1200"]
(left) Host pipe inspection and (right) site preparation - Courtesy of MDA Ltd[/caption]
Project scope
The Environment Agency employed Atkins to design the culvert rehabilitation, with Kier appointed as main contractor who in turn appointed specialist contractor Matt Durbin Associates to consult on rehabilitation options and carry out the work. Given that the location was a highly trafficked residential area with minimum cover to the road, it was decided that lining with a structural GRP segment lining system offered the best solution and Amiblu‘s NC Line, non-circular GRP Structural Relining system was selected for the project. In total some 300 metres of Amiblu NC Line Arch Shape liner, 2360mm wide x 1350mm high was manufactured to the required WRC Type II standard and ISO 16611. Amiblu’s application engineers worked in partnership with Matt Durbin Associates to understand specific performance criteria required in order to create the optimal shaped pipe to fit the needs of the project and production started in January 2022 at Amiblu’s Gdansk factory in readiness to commence February deliveries. The culvert meandered with the local water course, and on inspection for the design of the linings was found to include long radius bends which were designed for pre-manufacture so that they would install without issue on site. Despite the apparent loss of cross-section in the culvert the design and smooth internal finish of the linings ensured that the flow capacity requirements for the culvert would be met. Given the small village size and the traffic management requirements for the installation works, coordination with local residents and parish councils regarding the large deliveries to site was essential and worked extremely well. [caption id="" align="alignnone" width="1200"]
Amiblu NC Line 2360 x1350mm ready for installation[/caption]
Work commenced on site on 14 February with site preparation works. Installation into the culvert commenced in March. In total, all installation and annulus grouting operations were completed in just 8 weeks.
Amiblu’s NC Line provides structural rehabilitation to existing non- circular culverts and host pipes that have reached a point in their service life where the asset owner must decide to renovate or replace.
GRP pipe systems made by Amiblu maintain excellent long-term stiffness, corrosion and abrasion resistance and are engineered for 150 years‘ service life.
Project parameters
- Country: UK
- City: East Budleigh
- Year: 2022
- Application: Culvert reline
- Installation: Trenchless
- Technology: Amiblu NC Line
- Total length of pipe: 300m
- Nominal Diameter DN (mm): 2360 x 1350mm
- Nominal Pressure PN (bar): PN1
- Nominal Stiffness SN (N/mm2): As per design criteria
Supply chain
- Client: Environment Agency
- Contractor: Matt Durbin Associates Ltd
- Consulting engineer: Atkins
- Structural GRP pipe liner: Amiblu
Completed installation - Courtesy of MDA Ltd[/caption]
What they said
Daniel Gay, Project Manager for the Environment Agency:“From a client perspective, the GRP liner solution has provided a cost and time-effective approach to prolonging the asset life. We were hopeful to avoid any requirement for open cut solutions to minimise the impact to the local community and meet delivery deadlines. We also needed to ensure that the flood risk standard of protection was not altered to upstream or downstream receptors. The structural GRP liner allowed for a bespoke unit to be installed which optimised the culvert capacity to retain the flow performance and extended the life. The outcome of improvements to the culvert have reduced flood risk to 27 residential properties, significantly reduced future maintenance costs and health and safety risks to the public.”
Adrian Parker, Senior Project Manager, Kier:“This project is a great example of how accelerated delivery can be achieved under the Environment Agency’s Collaborative Delivery Framework. From identification of the scheme for fast tracking in June 2021, the scheme was on the ground in February 22 and complete by June 22. MDA have done a great job and thanks also to Amiblu.”
For more information: Amiblu UK | +44 (0)7786 013574 | www.amiblu.com
- Raigersfeld Culvert Re-lining
Raigersfeld Culvert Re-liningKent County Council‘s programme of planned highways maintenance works to be carried out during 2019 – 2021 included strengthening works to structures such as the Raigersfeld Culvert situated beneath the A20 Ashford Road, Maidstone, Kent. Following on from previous culvert rehabilitation works for Kent County Council, Steadline Ltd. were once again commissioned to make the required improvements to an existing historical brick and steel beamed culvert which was showing signs of deterioration resulting the restriction of flow capacity. With the same project team comprising Steadline Ltd., BdR (Civil & Structural Engineering) Ltd. and Amiblu, a bespoke, non-circular GRP liner was designed with specific challenges to overcome, including:- Steel cross sections to the soffit of the culvert
- Inconsistent shape
- Traffic loads
- Restricted access
- Environmental considerations
Existing Raigersfield culvert - Courtesy of Steadline Ltd[/caption]
The result, 16m x 1m length sections, 1244mm x 754mm Eliptical shaped NC Line with a 27mm wall weighing just 175kg per metre with a push fit bell & spigot socket, was designed to maintain the required cross section and flow capacity.
Steadline Ltd and BdR (Civil & Structural Engineering) Ltd worked in conjunction with Kent County Council, to ensure all works were carried out safely and efficiently whilst meeting the requirements set out by the client in respect of strength, durability and finished aesthetics.
Forward planning of this scheme was critical as the culvert runs beneath the main A20 which is a major arterial route through Maidstone and a road closure was never an option, so the team at Steadline worked closely with park rangers within Mote Park to secure the downstream access and with residents of a gated housing estate for the upstream access.
The stream was damned and over-pumped with precautions in place to ensure that no unwanted debris found its way into the natural water course. The 1m long NC Line sections were then craned onto the upstream landing area before being installed using a purpose built roller system to accommodate for the inconsistent internal condition of the existing culvert.
Once all 16m of NC Line had been installed, grouting was carried out in stages as per Amiblu’s recommendations and the headwalls were finished in keeping with the original culvert construction.
Amiblu relining pipes are particularly suitable for pipe and culvert rehabilitation, as they are light in weight, corrosion resistant, quality assured, easy to install and engineered to give 150 years’ service life, they are manufactured in a wide range of sizes in both circular and non-circular options and with varying strengths to cater for all locations and performance criteria.
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NC Line example shape options[/caption]
Amiblu NC Line pipes are produced to ISO16611. The non-circular cross-sections are ideal for relining and strengthening aging sewer networks, culverts and channels. Non-circular pipes are also used for open trench applications where capacity is required, but allowable depth to invert is limited. They can be customised according to project requirements and easily be adapted to different types of shapes and geometries.
Project parameters
- Country: UK
- City: Maidstone
- Year of construction: 2021
- Application: Storm sewer
- Installation: Trenchless
- Technology: Amiblu NC Line
- Total length of pipe: 16m
- Nominal diameter DN: 1244mm x 754mm
- Nominal pressure PN (bar): PN1
- NC Line shape: Elliptical (1m lengths)
Supply chain
- Client: Kent County Council
- Contractor: Steadline Ltd
- Engineer: BdR (Civil & Structural Engineering) Ltd
- NC Line relining pipe: Amiblu
(left & right) Finished Ragstone headwalls courtesy of Steadline Ltd and (middle) Amiblu NC Line Raigersfield design drawing - Courtesy of Amiblu[/caption]
What was said
Aaron Harber, Contracts Manager, Steadline Ltd.” All in all the scheme was very successful and certainly improved the flow of the stream/small river and with the new rag stone head walls looked very pleasing to the eye.”
For more information: Amiblu UK | +44 (0)7786 013574 | www.amiblu.com
- Gipsy Patch Lane (Bristol) Sewer Rehabilitation
Gipsy Patch Lane (Bristol) Sewer Reh...Gipsy Patch Lane, Bristol is a main road forming part of a new Cribbs Patchway Metrobus route in South Gloucestershire. As part of an asset assesment programme a few years ago, a CCTV survey showed many defects throughout the length of the surface water culvert at Gipsy Patch Lane. The defective sections ran under the busy carriageway so, as an interim maintenance measure the local authority excavated a section of the road and installed a concrete slab over the pipe to protect it from further deterioration or collapse. During heavy rainfall over the summer of 2020, the same pipe was found to have suffered structural defects and root ingress through open joints and connecting laterals resulting in localised blockages of up to 90%. A new man-entry survey showed the pipe beneath the concrete slab to be deformed. Major works were already under way in the area to replace a railway bridge on Gipsy Patch Lane, so South Gloucestershire Council took the opportunity to make improvements to the sewer in conjunction with the Network Rail works to minimise disruption, which was further aided by lighter traffic due to the regulations set in place for Covid-19 pandemic. Under the Council’s Climate Resilient Scheme, the task was to find and deliver a suitable solution before opening the road up to traffic and risking a pipe collapse; two options were considered; open-cut to replace the section of pipe or trenchless technology to reline the affected pipe with little disruption to the area. [caption id="" align="alignnone" width="1200"]
First post-Brexit delivery of Amiblu pipes (January 2021)[/caption]
Doug MacKay, Project manager, South Gloucestershire Council consulted with Julian Britton, Critical Sewers Manager, Wessex Water and Matt Durbin Associates; specialist confined space and GRP structural relining installer to determine the most efficient and economic technique. As with many suburban roads, Gipsy Patch Lane is laden with many services within the carriageway, so rehabiliatation of the existing pipeline through trenchless installation of 210m x DN800 structural GRP jacking pipe supplied by Amiblu was decided upon. As the contract was classed as emergency works, subject to time constraints and speed of execution the use of Amiblu’s GRP pipes meant that MDA were able to remove the need for costly over-pumping and install the pipes in live flows, whilst minimising their work area to a single lane closure for uninterupted access to local businesses.
During the installation of the initial contracted 210m, a further 70m section of the pipe downstream required attention, so MDA undertook the additional works saving additional costs and disruption at a later date.
Amiblu jacking pipes are often utilised in pipe rehabilitation projects such as this as they offer a high compressive strength and, compared with conventional materials, an improved hydraulic coefficient. The hydraulic analysis carried out for Gipsy Patch Lane showed no reduction in hydraulic performance and as the pipes are designed to offer a service life in excess of 150 years with minimal maintenance, the life expectancy of this asset is greatly improved.
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(left) GRP pipe installation and (right) the completed relining - Courtesy of MDA Ltd[/caption]
Doug MacKay, Project Manager with South Gloucestershire Council, commented:
"For this project, the Council had concerns about the risk of potential pipe collapse under traffic loading. The fact that road was already under a full closure due to an adjacent project to replace an old railway bridge meant that timing was critical for this project. It was essential that the work had to be completed before the proposed re-opening of the carriageway. Additionally, there was a limit to the funds available through the Climate Resilience budget to complete the scheme. We worked very closely with MDA and our designers to review the site constraints, risks to programme delivery and budget constraints to determine the most appropriate remedial solution. I was grateful for the time, input and patience spent by MDA during this period to explain the construction process and provide answers to all our questions and concerns in advance of making the final decision on the preferred option.
Once the decision was made to proceed with the pipe-jacking option the process was relatively straight-forward and stress-free from the Council side of things. In the main this was down to the excellent communication, planning and execution of the works by MDA. Both projects were completed on-time, within budget and with minimal disruption to the public and businesses that rely on using Gipsy Patch Lane.”
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Amiblu pipes require minimal site storage - Courtesy of MDA Ltd[/caption]
Project details
- Country / city: UK, Bristol
- Year of construction: 2021
- Installation time: 4 weeks
- Application: Sewer rehabilitation
- Installation: Trenchless technology
- Technology: Hobas
- Total length of pipe: 280m
- Nominal diameter DN (mm): DN800
- Nominal pressure PN (bar): PN1
- Nominal stiffness SN (N/mm²): 32,000
Supply chain
- Client: South Gloucester Council
- Contractor: Matt Durbin Associates Ltd
- Consulting engineer: South Gloucester Council
- Structural GRP jacking pipe: Amiblu
Amiblu Structural Relining Pipes
Amiblu pipes have a smooth, resin rich internal surface with high abrasion resistance which consistently prevents fouling and build up, leading to low maintenance costs and high flow rates even at low gradients. Both Jacking and relining pipes are supplied with in-line flush joints which prevent the intrusion of roots and further ensure the integrity of the asset. Available in diameters from DN300 to DN3600, in varying strengths and lengths. Amiblu’s systems are cost effect, durable alternatives to traditional pipe systems.
For more information: Amiblu UK | +44 (0)7786 013574 | www.amiblu.com