JORDAN VAN BEEK
Project Engineer – Wessex Water
Somerton Sewer Rehab
Proactive CCTV inspection of the foul sewer identified the need to repair significant structural defects (grades 4 and 5) in the vitrified clay sewers in Somerton, covering a total of 571 metres of pipe ranging in sizes from 225mm to 375mm in diameter. The sites are located in a residential area and within private fields.
I obtained permission from landowners to access their private land. Accessing certain lengths was challenging due to steep terrain and woodland cover. As work was scheduled for May 2024, I sought advice from an ecologist to survey the woodland. They confirmed no active protected habitats for nesting birds, badgers, and great crested newts. Additionally, there was also an absence of invasive species that could be disturbed. A tree arboriculture surveyor provided specialist advice on our working area and the ecological constraints to follow whilst working around the tree branches and roots.
Flow management was a challenge at 81.95 l/s. It combined the existing local service with two rising mains from neighbouring pumping stations, discharging into a single manhole chamber where the lining was being installed. The flow rate was calculated using telemetry readings from our network sensors. I was responsible for the over-pumping design, and it was decided to implement a combination of flow management methods, including overland pipe and the use of tankers, due to the terrain not supporting a solely over-pumping method.
A desktop survey using hydraulic models, followed by a discussion with the technical manager identified two critical assets within the catchment, a bifurcation and combined sewer overflow (CSO). These assets posed a potential pollution risk if not properly managed during renovation due to the possibility of spills. A site survey confirmed the asset’s locations and current conditions, and an assessment on the impact of lining on pass-forward flows (PFF) was carried out. It was agreed that modification of the weir height was necessary to ensure that the consented PFF was met and that there was no deterioration in performance compared to pre-lining.
Before construction, health and safety documents were managed in accordance with CDM (Construction and Design Management) Regulations 2015. Effective communication and quality assurance from stakeholders played a crucial role in the overall success of the renovation project. This was evident through all planned lining work completed on time and within budget. We received positive feedback from customers.
Bedminster Bristol Sewer Rehab
Another interesting project I delivered was in Bedminster, Bristol where the scope of work comprised of 50 metres of 450mm brick foul sewers. Results from the CCTV revealed significant structural defects grade 4. The site was located in the road and a closure was required.
The decision to use UV (Ultraviolet) liner for the repairs was based on several reasons. First, polyester resin produces an odour that could become an airborne pollutant. The sewer was situated at the head of the network branch in a densely populated residential area, characterised by low flow rates. These conditions increased the risk of odorous gases travelling up private lateral connections and entering residential homes.
Secondly, UV offers several benefits. Its accelerated curing speeds can shorten the working hours needed to achieve the repair. This will be particularly beneficial in the coming years as the demand for water bodies to improve their existing assets increases. A quick repair comparing to water curing led to the early re-opening of the road, reducing residential disturbances. It also saved operational energy on-site (welfare facilities, over pumping system) and minimized idle vehicle traffic, cutting carbon emissions.
Conclusion
If the CSO had overflowed in Somerton, resulting in a pollution incident, the consequences would have been severe from both financial and public relations perspectives. The public would likely view this as further evidence of mismanagement of the sewer network, leading to pollution of the extensive green lands and woodlands that define the countryside town of Somerton. This would undermine public confidence in our commitment to environmental improvement. Financially, addressing the incident would require extensive clean up efforts to mitigate contamination, followed by the restoration of the affected areas to their original condition. The costs associated with these activities, along with potential regulatory fines and reputational damage, would be substantial.
Customer satisfaction is a top priority for Wessex Water, and we are committed to going beyond expectations to ensure it remains a constant. Before starting any projects, we provide advanced notice to all affected customers through various media channels, such as mailed letters, warning signs, council announcements, and personalised notices for our priority customers, such as those who are water-dependent or disabled. Throughout the construction phase, I take calls from concerned customers. I address their concerns and work with them to find a satisfactory solution, from relocating waste bins for weekly collection, using quieter generators for night work, and conducting personal site visits to provide a visual explanation face-to-face.
What is next for me?
I am currently a BEng student at the University of the West of England, pursuing a degree apprenticeship in Civil Engineering, and I am continually seeking opportunities to expand my knowledge in the sector. As part of my CPD (Continuing Professional Development), I have attended training courses on trenchless technology by IKT (Institute for Underground Infrastructure) in Germany and participated in UKSTT masterclasses to stay updated on innovative industry techniques. Additionally, I take secondments within Wessex Water to understand the methodologies used by our internal departments, attending sites to see the combination of theory and practical application.
In the future, I intend to utilise my knowledge and experience to assist third-world countries. A reliable sanitary network is a crucial necessity often not prioritised, affecting billions of people who lack the resources to maintain their assets and draw attention to this need.
KIRAN ALYA KHAN
Gate-Keeper – Cappagh Group of Companies
The Hedingham Road project was the result of severely deformed and deteriorating pipes, requiring continuous over-pumping until completion and customer escalation. Initially, 30 meters of re-rounding and lining were completed in June 2023, followed by 38 meters of sewer re-lay in September 2023. During inspection, additional sections of mass pitch fibre and misshapen pipe were identified. We collaborated with the client to repair all defective sewer pipes on this street, transforming it into a project that impacted 17 properties and covered six sections totalling 140 meters. To minimize risk and maximize effectiveness, we used a combination of trenchless and civil methods, aiming to rehabilitate the sewer line before further deterioration.
Planning Stage
The project began on February 1, 2024, with a four-week deadline. Working across multiple properties posed challenges, so I prioritized face-to-face customer contact to build trust and provide a personal connection. The onsite supervisor and I answered customer questions and provided letters with an overview of the work. I maintained ongoing engagement and planned the work around customer availability to minimize disruption.
Due to the pipe condition and sewer layout, we installed three manholes on private lines for re-rounding and full-length lining. Two customers agreed immediately, while the third initially resisted. After a meeting with our technical specialist and the client, the customer understood the benefits and agreed under specific conditions for work on her property.
Method
Selecting the appropriate method for full-length lining was crucial. I determined that LED lining using the Magnavity system was the most suitable option, offering several advantages:
• Faster curing times
• Cost-effectiveness and eco-friendliness, with no by-products
• Absence of residual odour which is important when working near multiple properties
• Lower risk of errors due to UV light-activated liner and chemicals
• Self-setting control box system for pre-calculated curing speed
• Easy transportability due to its modular, lightweight construction
Materials
Choosing materials required careful consideration of each line’s condition, depth, diameter, bends, and overall state. Using our bespoke liner design table, I identified Brawoliner at a standard 3mm thickness paired with Brawo SRR resin as the perfect fit for all six sections, working seamlessly with the Magnavity system.
Installation Process
The project was completed in15 days which included everything from enabling to installation of manholes and lining of all sections. We utilised a recycler unit for extensive cleaning on all lines, removing mass amounts of debris. We then used a solo pro to review the condition of the lines ensuring there was minimal points of risk for re-rounding. The line was severely blistered and deformed in some areas proving difficult to reround. In some section, we used a picote maxi miller to carefully cut back some of the pitch fibre blisters. We used the combi unit in intervals to provide a light clean after each time the pig was winched through the pitch fibre line. After re-rounding each section removing blisters and restoring as much of the shape as possible, Brawoliner was installed using the magnavity curing system. The ims comfort was then used to reopen any laterals on each line. Finally, a post survey was completed using the solo pro.
Safety Compliance
Field engineers carried safety folders with COSHH assessments, risk assessments, emergency contacts, NRSWA code of practice, and daily/site-specific safety assessments, including:
• Point of work risk assessments
• Confined space entry permits and logs
• Confined space equipment pre-checks
• Work equipment inspection records
• Jetting unit checklists
• Site visitor records
Documents were reviewed by the site supervisor and stored for six months. The system we use to document work (Salesforce) required engineers to complete checklists before updating job statuses with notes, pictures, and closure details. For materials and installation, a strict process ensured suitability for the sewer repair type, diameter, depth, and environment, including liner installation check sheets, wet-out protocols, downloadable installation protocols, and testing samples for structural integrity, leak-tightness, and flexural modulus.
Contribution to the Project
Before the project, I met with the client to discuss pitch fibre issues across North London. We identified problematic streets and suggested rehabilitating entire sections to reduce repeat complaints, blockages, and extend asset lifespan. This approach generated multiple small projects for trenchless repairs before full deterioration necessitated civil work.
Throughout management and planning of the project, I provided the client with daily updates on our onsite progress, keeping them informed and allowing for any questions. The client was pleasantly surprised by the project’s efficiency and the cost savings achieved by combining the two methods. The estimated cost for full excavation was £54,665.30, but using the combined method, we reduced the expense to £15,604.00, saving the client £39,061.30.
Contribution to the Industry
Since April 2023, I have continued educating clients and employees about trenchless methods, promoting long-term solutions like full-length sewer lining over temporary fixes. The Hedingham Road project exemplifies this effort and aligns with other projects I have led.
In June 2023, I began focusing on combining trenchless and civil work, converting civil work to trenchless where possible. Reviewing countless surveys, I identified methods for combined works to fully utilise the practice of trenchless methods. This practice breaks the notion that work must be exclusively trenchless or civil. From September 2023 to June 2024, this approach saved the client £725,300.00, demonstrating the benefits of merging methods.
Vision for the Future
Trenchless technology offers many advantages over traditional civil work, but it is often underutilized. My vision is to educate clients and contractors about the benefits of addressing defective and pitch fibre pipes before full deterioration. Proactively rehabilitating entire lines and combining methods rather than point repairs can effectively reduce the need for large excavations. This approach will lead to:
• Reduced costs
• Lower carbon footprint
• Less time on site
• Fewer customer escalations by addressing issues early
• Minimal to no excavation required
• Increased sewer line lifespan
Furthermore, I am eager to collaborate internationally, sharing UK practices and learning from peers worldwide. Building connections and learning from diverse practices are essential for growth and development in this field, and I hope to further my career and passion for trenchless work through these opportunities.
