In 2021 WCI developed a foul drainage strategy to support ambitious plans for a ten-year renovation of the iconic Burgh Island Hotel in South Devon. This was to be the first major development of the hotel to come for 90 years and, as such, would require significant upgrades to its services and infrastructure.
With the hotel’s grand plans in mind, WCI’s proposed solution allowed for all important future buildability while meeting the demanding treatment standard associated with adjacent bathing waters. Fast forward to 2024 and WCI was thrilled to win the contract to complete construction of the design.
Our initial drainage strategy considered three possible options but concluded that a discharge of treated effluent to the sea, under an Environment Agency permit was the only viable solution. The design was based around a modular series of tanks that could be transported from the mainland over the tidal sand causeway. The tanks would then be hauled up a disused WW2 slipway that we would reinstate for construction purposes, thereby avoiding the listed Pilchard Inn on the main slipway. Even on paper it promised to be one of our most challenging projects!
WCI selected a WCSEE HiPAF sewage treatment plant having considered access restrictions and seasonality of flows – as well as environmental factors such as noise, visual footprint and energy consumption.
The Marine Management Organisation (MMO) were contacted to obtain the necessary permissions for the work along and close to the foreshore. Once granted, the temporary reinstatement of the WW2 slipway was completed so that the main works could begin.
The first phase of construction, arguably the hardest, was the accumulation of materials to the island. Circa 160 tonnes of aggregates were imported to the main carpark in Bigbury on Sea before being transported across to the island in a succession of dumper trucks and tractors. The logistics involved in traffic and people management, not to mention consideration of tide times, presented a significant challenge.
Once materials were received on the island the second phase was the installation of the below ground primary tank. Measuring more than five metres in length the excavation to connect to the existing drainage was around four metres. During the dig we encountered a large seam of rock which required an additional excavator with a pecker to be imported to the island to get the job done. Once dug the tank was carefully lowered into place, ballasted and backfilled with a granular fill.
A duplex pumping station was installed to pump from the primary tank to the above ground treatment plant and a concrete slab was constructed above the tank for protection and to allow vehicles access over the tank.
Next up, was the construction of a split-level concrete slab that would eventually receive the two overground tanks.
The WCS treatment plant was transported to Bigbury and then carefully taken across to the island. With the holiday season in full swing, minimising disruption was essential, so the tank was delivered and offloaded early in the morning. This timing allowed for a smooth crossing to the island, completed before the tide came in and before the car park and island filled up with tourists.
Once the split-level concrete slab was completed the tanks were carefully lowered into place ensuring that they were able to meet up exactly with the inspection chambers, sludge return, pump station and the outlet.
A trench of some 90 metres was dug back to the electrical feed and a three-phase connection was made by our electricians. Two kiosks were installed alongside the treatment plants containing the necessary control panels to run the treatment plant.
The final phase of the construction was the completion of the outlet. Heavy-duty cast-iron pipe was laid firstly down over the cliff and then across to the low tide level. Once complete the commissioning of the treatment system could take place by a WCI British Water accredited Service Engineer marking the culmination of this ambitious project.
Burgh Island Hotel now benefits from a robust, sustainable wastewater solution that meets rigorous environmental standards and supports the hotel’s future development. Overcoming logistical challenges, including tide-dependent transport, site restrictions, and complex installation requirements, WCI delivered a fully integrated system designed to handle the hotel’s wastewater needs efficiently for years to come. This project is a testament to WCI’s commitment to innovative, site-sensitive engineering, ensuring that this historic landmark can continue to welcome guests while protecting the surrounding environment.
