Supply Chain - Reservoirs - Raw Water - Pipework & Fittings

The village of Longwood is located in south-west County Meath, Ireland, approximately 15km south of the town of Trim and 50km north-west of Dublin. In March 2023, construction started on a 500m3 above-ground treated water storage tank at the site of the existing Longwood Water Treatment Plant, which will ensure that Uisce Éireann can secure supplies to over 1,244 customers in the Longwood Water Supply Zone; providing a safe and sustainable source of drinking water. Project background

The Longwood Water Supply Zone (WSZ) had been identified as having insufficient capacity and before the construction of the new treated water storage tank, there were no storage facilities for the Longwood WSZ. To ensure security of supply, it was necessary for Longwood WTP to be upgraded to provide 24-hours of storage, more flexibility and network management.

Ensuring the additional storage required constructing a new 500m3 treated water storage reservoir, replacing the two existing borehole pumps to improve efficiency and longevity of the units, and constructing a high-lift network pumping station designed to maximise the efficiency of the pumping system.

[caption id="attachment_21002" align="alignnone" width="1200"] The existing water treatment plant prior to the construction of the clean water storage tank - Courtesy of Uisce Éireann[/caption] Project design

The detailed design works included the following for the structural works, drainage, mechanical and electrical installation, and the photovoltaic system:

A 500m3 capacity drinking water storage reservoir at the Longwood WTP, including pipework connections, scour and overflow. Replacement of two number existing borehole pumps (both boreholes were in operational use on a duty/standby rota system; programmed to change duty every 12 hours). High-lift network pumping station kiosk for the Longwood WSZ, containing three booster pumps (duty/duty/standby). Integration into the existing Longwood WSZ Distribution Network. Modifications to the existing chlorine dosing and control system to ensure adequate disinfection contact time is provided within the new storage reservoir in compliance with Uisce Éireann’s Primary Disinfection Specification (IW-TEC-900-05 & IW-TEC-900-05-01) and Uisce Éireann’s Design Specification: Disinfection: Secondary Chlorination (Document No: IW-TEC-900-05-02). Provision of free chlorine residual monitoring system. Provision for emergency generator connection. All automation and control including modifications to the existing SCADA/HMI system. Design of a de-chlorination chamber. Design of a photovoltaic system. Associated site works including landscaping, site fencing and surface water drainage system. [caption id="attachment_21000" align="alignnone" width="1200"] Kiosk housing three booster pumps - Courtesy of Uisce Éireann[/caption] Longwood Treated Water Storage Tank: Supply chain - key participants Client: Uisce Éireann Employer representative: Nicholas O’Dwyer Ltd Civils designers: McAdam Principal contractor: BSG Civil Engineering Ltd Mechanical & electrical design/construction: EPS Water PV system: Solmatix Renewables Ltd Concrete testing: Mattest Ireland Ltd CBR plate bearing tests: Construction Testing Services Ltd Control system programming: ECN Technologies Control panel: Motrol Steel fixing, formwork and concrete: ONCCE Ltd Davit sockets: Columbus McKinnon Corp Ltd Booster pumps: DP Pumps Borehole pumps: Xylem Water Solutions Pump & control panel kiosk: Shanette Sheds Ltd Ductile iron pipework: APP Fusion Group Oil interceptor: Kingspan Klargester Precast manholes: FP McCann Ltd Drainage & manhole covers: J McAleer & Sons Ltd Handrails & access system: MEGS Fabrication Ltd Haulage & disposal: J Ryan Haulage Ltd Access covers: Technocover Ltd Rebar: Walter Watson Concrete & stone: Kilsaran Tarmacadam: Mitchell Macadam Ltd General hardware: Murdocks Builders Merchants Sustainability measures - PV system and carbon reduction

The photovoltaic system was designed to provide around 10% of the Longwood Water Treatment Plant’s annual power consumption. The system, supplied by Solmatix Renewables Ltd, is expected to generate approximately 5,168 kWh per annum; resulting in Uisce Éireann reducing the carbon emissions generated from the Longwood WTP by approximately 1,170 kg annually.

Through design of the landscaping and planting elements, a biodiversity net-gain was achieved at the site. This included the planting of approximately 65m of mixed native hedgerow to bolster an existing hedgerow and to protect an existing open drain at the rear of the site.

[caption id="attachment_20999" align="alignnone" width="1200"] Photovoltaic system on the roof of the new treated water tank - Courtesy of Uisce Éireann[/caption] Project construction

BSG Civil Engineering Ltd was employed as the main contractor and construction started on site in March 2023. The construction works included:

Construction of in situ concrete 500m3 capacity dual cell water storage reservoir. Installation of the inlet and outlet pipework to each of the storage reservoir cells, overflow and scour pipework into each cell linking it to the existing outfall, and interconnecting pipework and pressure regulating valves linking the storage reservoir to the Longwood WSZ. Installation and construction of four openings to the new storage reservoir, two for each cell. One opening in each cell is provided with a davit socket and a permanent internal access ladder. Construction of a de-chlorination chamber. Installation of a secured external staircase for access to the roof of the storage reservoir. Installation of a high-lift network pumping station kiosk for the Longwood WSZ. Installation of three booster pumps (duty/duty/standby within a new pumping station kiosk. Site drainage pipework including seven manholes, an oil interceptor, a de-chlorination chamber and a new headwall to allow discharge to existing outfall. Replacement of two existing borehole pumps along with associated pipework, sensors and cabling. Installation of a photovoltaic system and associated electrical works. Installation and upgrade of external generator connection point. Construction of roadway, footpaths and landscaping around the site. [caption id="attachment_21025" align="alignnone" width="1200"] The completed water treatment plant site - Courtesy of Uisce Éireann[/caption] Final considerations

The project was successfully completed and handed back to Uisce Éireann in December 2024 and was a testament to the skill of all involved.

Nicholas O’Dwyer’s initial design concept, which was carried forward by BSG Civil Engineering Ltd, met all of Uisce Éireann requirements and the upgrades at the water treatment plant provide a safe, secure and sustainable source of drinking water to the Longwood Water Supply Zone for years to come.

Utilising a photovoltaic system will ensure a continued reduction of Uisce Éireann’s carbon footprint, and reusing all the excavated materials generated from the construction at a local sports facility for use in future development works has benefited the local community by enhancing the sports facility and the community as a whole, due to the fact the excavated material is not going to landfill.

Clough Bottom Impounding Reservoir (IR) is an earth-fill embankment reservoir located on the eastern edge of the West Pennine Moors, around 4km north east of Rawtenstall, Lancashire. The reservoir is currently used for public water supply and compensation flows. The reservoir was formed by the construction of an earth embankment across the Whitewell Brook and Clough Bottom.  The dam is an earth embankment with puddle clay core approximately 23m high and 381m long. The embankment has a clay core shown to extend into the foundation over the central section of the dam through the original stream channel. Current facilities and reason for work The main objective of the work was to future-proof the existing dam structure and Victorian spillway, increasing resilience and helping to mitigate against the potential impacts of climate change, while meeting United Utilities’ requirements and regulatory commitments. The scope of work included: Construction of a new wave wall structure. Lining of the existing spillway including along with construction of a portal opening across the scour entrance to the spillway. Removal of the existing gauging weir and replacing with newly constructed flow monitoring. Redesign and rebuild and the lower access bridge to a more accessible location. There was an obligation for United Utilities to achieve the scope of improvements to meet regulatory commitments, while ensuring the integrity of the reservoir structure and maintaining supply and compensation flows to the water course throughout the works. The project set out to achieve the objectives and project requirements by applying a culture of efficiency and collaboration through collaborative design and construction. Collaborative design process Due to the complex nature of the work and site constraints, there was a clear need to innovate in both solution and design. From the outset, the team established a culture of collaboration, engaging at the earliest opportunity to identify constraints and opportunities. The initial design solution was undertaken by United Utilities in collaboration with the reservoir panel engineer. Upon instruction, Costain’s in-house engineering team developed the detailed designs working collaboratively with the United Utilities engineering team to ensure design efficiencies, constructability and timely construction. The team undertook extensive method and temporary works/enabling works planning to ensure the work could be undertaken safely, both in terms of conventional construction safety, and also considering dam safety constraints, through appropriate dialogue with the resident panel engineer. Clough Bottom Reservoir: Supply chain - key participants Client & outline designer: United Utilities Designer: Costain Wave wall design: GHD Civil sub-contractor: JVT Electrical connections: Water Engineering Services Ltd Bridge & electrical diversions: Pure Utilities [caption id="" align="alignnone" width="1200"] (left) The new wave wall upon completion, (top right) construction of the wavewall and, (bottom right) construction work on the spillway - Courtesy of Costain[/caption] Construction of the wave wall In terms of legacy, the most visual aspect of the project is the new wave wall, designed with a high-quality stone finish, in keeping with in keeping with the local context and area which is overlooked by a small residential community and used regularly for recreation purposes. Initial investigations were undertaken to explore the possibility of retaining the existing dry-stone wall while meeting safety requirements. However, as the original wall had little or no structural integrity this was not deemed possible. Different options were evaluated and assessed again the criteria set by the client. A concrete wall solution was agreed which would be built into the clay core and then upwards to create a new wave wall, with a stone facing tied into both sides and using the original 1895 topping stones to cap the wall. Dam safety was at the forefront of solution development, for example how could crest loading be limited during construction, and how could the length of time excavations being left open be minimised. The solution was to prefabricate the reinforcement cages in 5m sections, so that the removed area could be closed off quickly in the event of a storm in accordance with flood protection requirements. The new wave wall structure was built into the existing clay core through excavation, the prefabricated rebar was placed in the excavation, formwork installed and checked prior to pouring. The linear nature of the construction allowed learning and efficiencies to be implemented progressively. This approach reduced construction time along the 370m wave wall from an initial 7-day turnaround of each 5m section, to 4 days (-40% efficiency). Lean construction techniques such as these, where adjustments were made to the construction process in response to previous results, were testament to the success of the project as a whole. Considering the environment A project carbon baseline was established at an early stage which looked at the proposed materials and operational carbon. This formed a strategy to target and achieve reduction during the programme. The project targeted a 10% reduction vs the baseline. This included the use of use fibre concrete in the lower section reducing the amount of rebar required. The works were also connected to the mains power supply, which prevented the use of a diesel generator for the site welfare. Upon completion of the works, the haul road to the far side of the spillway was retained to give better permanent access to the client in the future. Another key priority was consideration of the environment used socially by walkers in such a scenic location. Investment in the design phase to consider visual impacts and legacy led to the design of a stone-clad wave wall utilising a combination of re-used and sourced stonework selected to be in keeping with the existing natural environment. The overall product was built to a high operational and aesthetic quality, providing a real tangible benefit for the surrounding community and those visiting the area for recreation. Completion Works were completed in a live reservoir environment, so it was important to ensure that operational access was maintained during the works. This required a collaborative approach to allow access for monitoring and regular statutory inspection of the dam. The works were delivered to a high standard of health and safety throughout, in accordance with the plan and ensuring regular communication with all stakeholders. An excellent Health & Safety record was maintained with no reported incidents throughout the project. The finished product provides not only the function but also in terms of the wave wall, a visually enhancing product in keeping with the environment. This asset was delivered with a real focus on efficiency through a ‘production thinking’ approach. From the outset, the team adopted collaborative behaviours during an ECI phase prior to the main D&B contract award, which enabled a ‘production thinking’ approach to maximise efficiency and dam safety considerations. Planning and production control techniques were developed throughout construction to ensure efficiency and enable the team to learn from one section to the next. Through this effort the team were able to reduce the construction duration by over 15%.

Llyn Bran is located in Denbighshire, north-east Wales and was a natural lake that was raised in 1899 by a concrete dam. The reservoir was used to supply water to the North Wales Hospital in Denbigh. The hospital closed in 1995 and Llyn Bran has not been used for drinking water since. As part of a separate discontinuance scheme at Llyn Anafon, Llyn Bran was identified as a ‘compensatory site’ for the loss of habitat at Anafon. One element of turning Bran into a compensation site was the removal of the dam, as well as other ecological enhancements. Through careful restoration work, Llyn Bran will eventually become a Special Area of Conservation. The reason for Llyn Bran discontinuance Llyn Bran Reservoir is required as a ‘compensatory site’ for the loss of habitat area that will be caused by discontinuing the dam at Llyn Anafon Reservoir, as required by the Habitats Directive. Llyn Anafon Reservoir was originally a natural lake which was raised by 1.4m in 1931 through the construction of an embankment dam. The use of this site for local water supply ended in 2002. A 2016 S10 inspection of Llyn Anafon resulted in a MITIOS (Measures in the Interests of Safety) to “develop a long-term solution to the poor and deteriorating condition of the dam”. In January 2019, it was agreed with relevant regulators that to provide a long-term solution, the reservoir would need to be decommissioned, with the dam structure removed and the lake lowered by 1.4m. [caption id="" align="alignnone" width="1200"] Llyn Bran before discontinuance - Courtesy of Welsh Water[/caption] Llyn Anafon is nationally and internationally protected for specific conservation features. This means prior to any project taking place, a full Habitats Regulation Assessment (HRA) had to be undertaken. The outcome of this assessment was that it was not possible to avoid adverse impacts to protected features and as such, the only route to proceed with the project was under the “Imperative Reasons of Overriding Public Interest (IROPI)” (Article 6.4 of the Habitats Directive) on the grounds of public safety. The Anafon Dam Discontinuance Scheme is the first IROPI case of its kind in the UK and has recently been approved by Welsh Government. To satisfy the IROPI case, Welsh Water was required to secure ‘compensatory measures’ for the loss of habitat at Anafon. Using a set of criteria agreed with National Resources Wales (NRW), Llyn Bran was identified as the most suitable site to provide the necessary compensation. A key element of the work was to ‘restore and maintain hydrological functioning’ i.e., removal of the dam to create a natural lake and restore connectivity to the downstream watercourse. Although the primary reason for discontinuing Llyn Bran was for compensation, it also had the added benefit of removing a dam which was no longer needed for operational purposes. [caption id="" align="alignnone" width="1200"] Llyn Bran dam before discontinuance - Courtesy of Welsh Water[/caption] Scope of works Create temporary construction access using bog mats. Draw down the reservoir by means of siphon pipes and pumps. Remove silt from the area immediately upstream of the dam. Demolish the entire dam and remove arisings for disposal off-site. Restore the watercourse channel downstream of the retained natural lake, incorporating silt management and retention measures. Create new water vole habitat along the shore areas of the retained natural lake using coir matting. Demolish outbuildings and associated structures with all building waste removed for disposal off-site. Remove exposed sections of pipework. Buried pipework to be sealed and filled by grouting. Install new roadside fencing along the north end of the reservoir. Install rip-rap protection around the upstream end of the B4501 culvert. [caption id="" align="alignnone" width="1200"] Ground conditions - Courtesy of Welsh Water[/caption] As with all discontinuance schemes the various surveys, permits, consents and negotiations in advance of the physical works were particularly complex, taking more than two years to complete. An overview of the consents and constraints required is below: Impoundment Licence and SSSI consent from Natural Resources Wales (NRW). Permitted Development Certificate from Denbighshire CC. Ordinary Watercourse Consent from Denbighshire CC. Protected species licence required for trapping and temporarily removing water voles (this was needed before permitted development could be granted). Annex 1 Habitats present around lake margins. Reservoir drawdown rate limited to 120 l/s. HRA level 1 & 2 required. Peat bog deposits along route of temporary access track. Bat surveys required prior to demolition of valve house & boat house. Challenges & constraints Site access With no formal access track to the dam, and the surrounding land being designated as Annex 1 Habitat due to the presence of peat, access was one of the main challenges. With 140 peat depths probes taken along the route of the proposed access track, and working closely with NRW, a methodology was developed for installing over 280m of bogmats to the dam without the need to excavate and remove the top layer of peat. This minimised the potential damage to the peat and made site reinstatement far easier. [caption id="" align="alignnone" width="1200"] (left) Bog mat access track and (right) amphibious excavator used to load barge with coir matting - Courtesy of Welsh Water[/caption] Peat The extent of peat encountered on site was far greater than expected once construction began. This resulted in an entire change in the contractors methodology for the coir matting. It was initially planned to use Bog Master excavator and tracked dumper to access the western shore of the reservoir, however it quickly became clear this was not practical. Thanks to the contractor being proactive, the methodology was quickly changed to using an amphibious excavator and barge, to transport the coir matting across the reservoir. Water voles Water voles were identified on site during the early site survey stages, meaning a licence was required to temporarily remove the voles during construction. Six water voles were captured by specialists and were transferred to a facility in Kent, where they were looked after while the work took place. A condition of the licence was that there must be 5-days with no water voles captured before it could be concluded that all voles were removed from site. Rather unluckily, there were two occasions where a vole was captured at the end of the fifth day, meaning the process took far longer than expected and the licence had to be extended. The voles are due to return home to Llyn Bran this summer. [caption id="" align="alignnone" width="1200"] Water voles were captured and transferred to a facility in Kent for the duration of the works - Courtesy of Welsh Water[/caption] Compensation flow A condition of the NRW impoundment licence was for a continuous compensation flow of at least 20 l/s for the duration of the works. This meant pumping to the watercourse, which had to be continually monitored. It was hoped to use a cloud-based telematics tool that makes it easy to monitor the pumps off-site but unfortunately, due to lack of signal, this did not work meaning William Hughes Civil Engineering needed to attend site over the weekends to check on the compensation flows. The summer of 2022 proved to be exceptionally dry, which crated a challenge in meeting compensation flows whist also not allowing the remaining lake to become too low. Flood risk The existing reservoir provided significant flood attenuation meaning the discontinuance increased the flood risk to a downstream highway culvert. Initially, there were concerns from the highways department that the culvert would need to be upsized, which would have added significant costs to the project. Following a detailed flood risk and stability assessment, Welsh Water were able to prove that the increased flood risk would not adversely affect the culvert and only minimal slope protection work around the culvert was required. [caption id="" align="alignnone" width="1200"] Amphibious excavator forming the new channel connecting to the downstream watercourse - Courtesy of Welsh Water[/caption] Llyn Bran Reservoir Discontinuance Project Construction timeline: 16 May 2022 - 4 November 2022 Project cost: £1.7m Drivers: Dam safety | Habitats Directive | Reducing costs | Ecological compensation measures Supply chain - key participants Principal Contractor: William Hughes Civil Engineering Design Partner: Stillwater Associates Environmental Consultants: Ricardo Energy & Environment Ecology/water vole licensing: Wildwood Ecology Ltd Silt management: Salix River and Wetland Services Amphibious excavator hire: Land and Water Plant Opportunities & Savings Forestry culvert At the design stages there were concerns about the condition of a nearby downstream forestry culvert and its ability to accommodate the reservoir outflows during emptying. Expertise within Welsh Water was utilised by requesting a CCTV survey of the culvert via the wastewater team. The team provided a prompt and efficient service and enabled us to confirm the capacity and condition of the culvert. [caption id="" align="alignnone" width="1200"] Cores being drilled through concrete dam to allow any extreme storm flows to pass through - Courtesy of Welsh Water[/caption] Dam safety mitigation During detailed design, the Dam Safety Team suggested coring holes though the concrete dam once the reservoir was drawn down to the required level. This would mitigate the risk of the reservoir refilling during severe weather, before the dam was fully demolished. Fortunately, on this occasion the weather was favourable and the cores were not needed. This approach will be considered for any future concrete dam discontinuances. Waste removal It was agreed with NRW that the stone from the haul road and compound could be transferred to a nearby quarry, just down the road from site. This was done under a waste transfer notice, saving costs. The arisings from the dam were removed off site. The dam was demolished far easier and quicker than expected, making the removal of concrete straightforward. [caption id="" align="alignnone" width="1200"] Dam demolition in progress - Courtesy of Welsh Water[/caption] Coir matting Due to the silt being drier than anticipated, there was spare rolls of coir matting left over. Rather than this being wasted, it was moved to nearby Alwen WTW where it is being stored before being used for silt management on the upcoming Cilcain Discontinuance Scheme which is due to start this spring. The future for Llyn Bran The discontinuance will give significant biodiversity opportunities in relation to the marginal areas around the retained natural lake and with the restored connectivity to the watercourse. The retained lake will also be used as a receptor site for aquatic plants translocated from Llyn Anafon. Long term ecological monitoring of the lake is required to ensure the compensatory criteria are met. This includes water quality and macrophyte monitoring as well as botanical surveys to check the natural regeneration of exposed shore habitats. A condition of the water vole licence is that activity is monitored until 2034. Through careful management and monitoring of the site, it is hoped that Llyn Bran will become recognised as a Special Area of Conservation.

The challenge The reservoir had an estimated 180 meters of cracks that needed repair, as well as the main element of the concrete that required coating to waterproof and add durability to the concrete structure. The reservoir was taken out of commission but it needed to be returned to service as soon as possible. To do this, we looked at the order of the processes to ensure the tight time frames could be met. The Xypex Solution In accordance with the Reg. 31 IFU (Instructions For Use) all cracks were broken out to a minimum depth of 37mm and a width of 25mm. The walls were prepared by removing the laitance and the whole area was saturated. To stem the ingress of water, every crack that showed moisture was sealed with Xypex Patch’n Plug which sets in seconds stemming the flow. To meet the required time frame, the Xypex Concentrate coating work was then undertaken to allow it to air cure for the specified time. Once applied, the crystalline technology takes time to migrate deep into the concrete and become fixed within the concrete matrix as a permanent solution. When the curing is complete the coating could be removed if required, in this instance it remained. During the curing process of the coating, the crack repairs were then filled using Xypex Concentrate as a Dry Pack and then finally topped off with a thin layer of Xypex Patch’n Plug to enable the fast return to service. [caption id="" align="alignnone" width="1200"] The Xypex solution; Concentrate and Patch'n Plug - Courtesy of SMR Projects Ltd - Xypex UK Distributors[/caption] The results The allowed time frame meant undertaking the processes out of the normal sequence, but this allowed the repairs to be to be delivered on time. The coating was undertaken to increase the durability but also to pick up any minor unidentified cracks. The larger cracks were repaired and sealed using the standard Xypex repair methodology, however ultimately over 300 metres of crack repairs were completed.   For more information: SMR Projects Ltd - XYPEX UK Distributors: +44 (0)1295 279747 | www.smrxypex.co.uk

 

Scope of works Excavation works began in 2017 at the Dancing Hill Reservoir site as part of a £6 million project to upgrade the Water Supply GRID for Bridgwater and the surrounding areas. Major upgrades are required due to large-scale developments in the area. Issues & solutions The design was particularly challenging due to the complicated nature of the ground surrounding the reservoir tank. A sizeable berm was built on the ground profile around Cofferdam 4 to ensure a safe and stable excavation. This exaction also had to accept other loadings from Cofferdams 1, 2 and 3. Multiple 203UC tank brace frames were used due to the strict lift plan limit of 1 tonne. Larger or heavier brace systems could risk the collapse of existing foundations. Vibration pile driving was not permitted due to the detrimental effect it could have on the high-pressure water mains that supplies customers. There was also a HV cable running through the site that had to be avoided. The exact location of other services created additional challenges and ongoing surveys had to be monitored throughout the duration of works. As of 2017 there are four connected cofferdams in place allowing safe working space to combine new pipeworks to the main reservoir tank. Multiple back-to-back 203UC tank braces with special alignment of bracing has been key in the design, combined with KKD 600 sheets to secure the trench. Several Lightweight DavitSafe systems allow safe access into the 10m deep cofferdams. Sector: Water & Utilities Client: Wessex Water Location: Bridgewater, Somerset Scheme: Water Supply GRID Upgrade MGF depot: Bristol Products hired: Multiple 203UC brace, KKD 600 sheets, lightweight davit [caption id="" align="alignnone" width="1200"] Dancing Hill - Courtesy of MGF Ltd[/caption] For more information: MGF Ltd | +44 (0)1942 402700 | www.mgf.co.uk    

The challenge The South East Water contact tank has a constant output of 18.1 million litres per day, it contains water which is treated with Sodium Tripolyphosphate and sodium hypochlorite before entering the distribution network. The structure is of a ‘certain’ age and has a number of active leaks that have progressively worsened over time. As the tank is in constant use, it cannot be taken off-line and so a solution was required which could be undertaken against heavy flow of water with the tank still in use. The Xypex solution Xypex not only likes water, but the repair method requires a wet environment therefore an active leaking tank is not a problem. The cracks were chased out in accordance with the DWI Reg. 31 approved Instructions for Use Document i.e. a minimum of 37mm depth and 25mm wide, following the line of the crack. Either side of the crack was cleaned and the laitance removed to expose the capillary and pore network. [caption id="" align="alignnone" width="1200"] The Xypex solution; Concentrate and Patch'n Plug - Courtesy of SMR Projects Ltd - Xypex UK Distributors[/caption] A bleed pipe was installed and secured with Xypex Patch’n Plug at the lowest point of the crack where water flow was at its greatest. Then the base of the crack was plugged using Xypex Patch’n Plug to stop the flow of water. This was then left to see if there were any additional issues that manifested themselves over night. Once the flow was proven to have stopped, the repair was finished using Xypex Concentrate both as a dry pack and a slurry in line with the IFU and Xypex’s standard repair methodology. The results The Xypex methodology using Xypex Patch’n Plug stopped the flow of water instantly and allowed the repair to be undertaken. The crystalline chemistry within the Xypex Concentrate will migrate deep in to the concrete matrix around the repair, driving water out and increasing the life and durability of the tank in those areas. [caption id="" align="alignnone" width="1200"] Courtesy of SMR Projects Ltd - Xypex UK Distributors[/caption] As the original repairs were undertaken, additional pressure was transferred to other cracks that were visible, but not leaking, and these were all repaired using the same method. In all, only 2 materials were used on site and no specialist methods were used. SMR Projects Ltd attended and were on hand for technical help throughout the installation.   For more information: SMR Projects Ltd - XYPEX UK Distributors: +44 (0)1295 279747 | www.smrxypex.co.uk