Longue Hougue

LONGUE HOUGUE: WASTE TRANSFER STATION

When the States of Guernsey committed to a new waste strategy for the island, attention turned to the logistics of how to provide it. The Longue Hougue site on Guernsey’s eastern seaboard had previously been allocated as the area for waste management facilities, so the challenge was in building a facility there that met all the island’s needs. Local contractors, Geomarine, worked as the delivery partner with the UK specialist and lead contractor, Wood plc, to build the waste transfer station that deals with islanders’ rubbish.

Guernsey’s waste transfer station was completed in February this year at the end of a build that had started in May 2017. But while the construction work took less than two years, the planning of the project had taken a lot longer.

Tom Whitmore is the managing director of Geomarine in Guernsey. He said the time taken in planning was crucial to ensure that the plant met all of the States’ requirements. “We had three criteria when it came to designing the plant: its affordability; its value for

money; and its engineering. It was vital to prove both value for money during that period and that the plant would meet all the States’ needs.”

With a £25million budget, it was clearly an important project for the States. The general manager of States Works, Paul Lickley, explained how they managed the potential costs of the project: “During the process we had a huge focus on value engineering and making sure that our contractors gave us the best value throughout the project. We invested in having our own quantity surveyor, and had a rigorous approach to financial and contract management. When the original design came in outside of our budget, through the value engineering process we managed to re-evaluate the plans and come up with an innovative solution that was more cost-effective.” Once the plans were in place, work could finally start on site. There the contractors were meeting a remit for the waste transfer station that included the main facility with its sophisticated processing equipment and all the associated infrastructure that needed to be installed on the site, including telecoms, pumping mains, foul water drainage, weighbridges, roads and a facilities building.

The remit for the waste transfer station itself was a plant that could deal with 26,000 tonnes of black bag waste, 4,000 tonnes of food waste and 2,500 tonnes of glass per year. It’s a lot of rubbish, and as a crucial component of the island’s waste strategy, the infrastructure had to be right.

One of the first challenges Geomarine faced was the land they were working on. The Longue Hougue site comprises land that has been reclaimed from the sea using inert waste material from local construction projects. The issue for the contractors was that they didn’t know what was in the ground, and asbestos was a major concern. Luckily with a protocol in place and constant monitoring of airborne particles, that didn’t prove too much of a problem.

But while asbestos in the ground wasn’t an issue, other things were. Gary Stevenson is the operations director at Geomarine. He explained what they had to deal with: “When you have landfill like that, there can be a lot of voids that you are unaware of until you come across them while building. At the same time, there was a lot of steel etc. which had been put in the ground over the years, so it was definitely a challenge. We did a lot of piling in the area to ensure that the foundations of the building were secure.”

DURING THE PROCESS WE HAD A HUGE FOCUS ON VALUE ENGINEERING AND MAKING SURE THAT OUR CONTRACTORS GAVE US THE BEST VALUE THROUGHOUT THE PROJECT.

While the ground was an issue, so too was the location of the site itself. There are few areas on the island as exposed as Longue Hougue, and the contractors were working through some of the worst weather conditions the island had seen in years. When snow hit in February 2018, those on site were trying to erect the large steel frame and roof.

Gary said that, despite losing a few days to high winds, the breadth of their mandate meant that the poor weather didn’t hinder them as much as it could have done: “The advantage of this project was that we had a lot of different work in different areas running at the same time. Many construction projects are very linear but due to the size of the site, it had the capacity for us to change our workflow. The building itself was obviously a linear project, but outside of that we were working on the electrics, the telecoms, the roads etc. so we were often able to continue with other work even when the weather was very poor.” 14 The Longue Hougue site is a prominent feature of Guernsey’s eastern seaboard, and one that is clearly seen when anyone arrives by boat to the island. While practicality was clearly the priority, planners had made it clear that thought needed to be given to making the site as attractive as possible.

A number of measures were put into the design and build to try to soften the appearance of the industrial site.

For Paul, it was something that had to be considered at every stage of the planning process: “The design was a huge part of the planning for the site, and we had a comprehensive dialogue with planners regarding its appearance as they had clear expectations as to what they wanted. If you look at the building, there are a number of features that are there simply to make it more attractive, such as the two tone cladding to blend it into its surroundings, and the curved rather than flat roof.”

WE SPENT 180,000 HOURS ON THIS PROJECT AND ONLY HAD ONE LOST TIME INCIDENT. WITH THE RISK LEVELS WE WERE FACING, THAT’S A GREAT RECORD AND WE’RE VERY PROUD OF IT. Geomarine’s role also included external work to ensure the landscaping would help add to Longue Hougue’s appearance, as Tom explained: “There is extensive landscaping that has been done on site, with large vegetated earth banks combined with a major planting scheme. In another year, once it is fully planted, it will actually be quite a green site which will hopefully help it look more attractive. A lot of money has been spent on these design details but they should make it look a lot nicer when people are approaching the island and seeing this landmark.”

While appearances mattered with this project, so too did health and safety – and many features of the plant were thought about from an environmental health perspective. As with any waste plant, odour control was an issue. The main building has a large extraction system which runs through its centre, taking the air from the building and filtering it before emitting it again.

According to Gary, one prominent feature of the building doesn’t serve the purpose you might imagine: “The large chimney which is so prominent on the site is not for smoke, as many might initially think but is for the odour control system. The odours are taken out with the carbon filters before the air is expelled so there should be no detrimental effect for the neighbours due to the site’s location.”

While the chimney may not be for smoke, fire control was a major part of the design. The organic waste in the rubbish has a risk of self-combusting, so an extensive sprinkler system was installed in the building to ensure

that any fires can be effectively extinguished.

The long-term safety of the facility was clearly a major priority, but so too was the safety of those working on site. For Tom, it was an exemplary project for Geomarine: “One of the major issues for all of us working in construction is our safety record, and there is a huge onus on us to keep our employees safe at work. We measure safety through how much time is lost due to incidents where somebody has acquired a serious enough injury to take time off work. We spent 180,000 hours on this project and only had one lost time incident. With the risk levels we were facing, that’s a great record and we’re very proud of it.”

While the majority of the work was done by Geomarine’s staff on site, there were some areas in which other specialist contractors got involved. AFM provided a substantial package of electrical work, including the feeds for the waste processing plant.

With the work finished and the plant fully operational, Tom and his team are now looking back at the project with pride: “We’ve not only shown the breadth of our capabilities as a firm, but we have delivered an important piece of infrastructure for the island, which is central to the implementation of the waste strategy.

“The handover of the plant marked a substantial shift away from landfill and towards a more sustainable future for the island. It’s only been running for a few months and already the island is delivering some of the best household recycling rates in Europe. I’m very proud of the facility we’ve delivered, but also the fact that we’ve helped contribute to a more sustainable future for the island.”

LONGUE HOUGUE: HOUSEHOLD WASTE & RECYCLING CENTRE

Alongside the waste transfer station, the States needed provision at Longue Hougue for a household waste and recycling centre (HWRC). The previous temporary provision had been well-used by islanders for a decade, but posed real issues due to its makeshift design. The new facility, however, was carefully planned from the start, with contractors Rihoy & Son ensuring that they built a fit for purpose centre on the site.

As with the waste transfer station, the States completed a tender process for the HWRC. But with this project they were happy for contractors to show some independent creativity with their plans for the site.

Rob Roussel is the senior project manager at States Works. He explained the process: “We came up with a suggested design and system for everyone to tender against and all tenderers had to submit a bid against that, but they could also propose alternative designs if they had come up with a proposal that they believed could make better use of the site.”

Working with a UK expert, that was exactly what local contractor Rihoy & Son did. Operations director Robin Le Page said there were a number of advantages to their alternative proposal: “The original remit was a modular system which involved importing a significant package from a sub-contractor in Scandinavia. We believed our proposed scheme was much more flexible and had the advantage of using on-island sub-contractors and suppliers.”

For the States it made sense, as Rob explained: “When we saw their alternative proposal we thought it was the best solution. On a cost value assessment, it seemed to represent the best value for money for the island.”

On site, Rihoy’s first had to prepare the ground for the new facility. For Robin, that was a fairly simple procedure: “The land had been heavily trafficked by vehicles over a significant number of years so

WE WERE VERY KEEN ON THE IDEA OF SPLIT LEVELS WITH A ONE WAY SYSTEM IN PLACE FOR USERS TO NAVIGATE THEIR WAY AROUND. IT HELPS WITH THE EASE OF USE BUT ALSO WITH THE SAFETY OF THE ENTIRE SITE

the compaction of the ground was very good. We completed a full site investigation but ended up just needing to put a fairly simplistic reinforced concrete slab over the entire area.”

With that done, further work could start. The facility provides a number of skips and bins for various types of household waste, which needs to be segregated by users for recycling. One of the key differences from the island’s previous facilities is the multilevel nature of the site, which means that users can access receptacles from above – making it safer and easier for them to unload their items. A covered canopy provides storage for more high risk items such as batteries and fire extinguishers which could be susceptible to damage from the elements if left exposed.

For Rob, that two level system was key to the usability of the site: “We were very keen on the idea of split levels with a one way system in place for users to navigate their way around. It helps with the ease of use but also with the safety of the entire site. It also allowed us to segregate service vehicles from the public, which is again an important safety measure.”

Rihoy’s built a continuous circulation route for vehicles as well as public footpaths around the whole facility, making it easy to access by vehicle or foot.

Alongside the roadways, Robin said they also installed permanent buildings: “We provided a pre-fab reception hut that was bespoke for this project and gives the staff members on site some office space. We also provided units for the GO store, which collects items to be sold on behalf of the charity. Again, we ensured flexibility here as it is a space which can be added to if necessary.”

For Rihoy’s, the job went very much to plan, with no significant problems except for the weather and location issues that had also affected the building of the waste transfer station. “It was a nice job to manage because it was all sequential work,” said Robin. “We were laying down a large area of concrete in a very ordered patterned fashion from one side to the other. From a procedural point of view, it’s a good process as it’s quite repetitive and a good way to run a building side. Our main challenges certainly came from the location and its exposure to the weather. We weren’t just dealing with rain but with seawater and wind which did make things difficult.”

That seawater entailed a change to the original plans, when the drainage designs had to be amended to deal with the overspill of water from the sea on to the site. Aside from that, only very minor changes were made to the original plans, such as putting some protection around the base of the gantries to protect them from vehicle accidents.

The centre took exactly a year to construct, with Rihoy’s starting on site on 24 May 2018, and completing on 24 May this year.

Now it’s hoped it will be used by islanders for many years to come, and Rob said the signs couldn’t look more positive: “The new site speaks for itself in terms of user feedback and popularity. There is already a significantly higher general throughput than there was on the previous site. It is clearly working for those who use the site, and that’s good for the island.”

The household waste recycling centre is open to the public every day except Thursday. For a full list of the items that can be recycled and disposed of on site, visit www.gov.gg/hwrc