Young Professional

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.