Grand Case St Martin Caribbean

When Hurricane Irma wreaked havoc through the Caribbean Islands in 2017 leaving a trail of destruction, it was clear that many towns would need to be completely rebuild many of their buildings but also their water and sewage infrastructure.

Having already been engaged in other Caribbean countries to install Flovac vacuum sewerage systems the engineers in Grand Case on Saint Martin approached Flovac to see if a vacuum sewerage system would be the best technology for the island.

This area is very flat and has a high water table, which meant that you could not dig more than one meter without finding salt water that would damage a system using gravity piping networks. Until now Grand Case had a network based on septic tanks that was not adequate. After the damage caused by Hurricane Irma, Saint Martin needed urgent repairs and a new, more efficient sanitation system. Work began in Grand Case (Saint Martin)  towards the end of 2019 and it was clear that a vacuum sewerage system was essential in the area.

Shallow Vacuum Main Installation

Often working in narrow streets with other cables and pipes already installed it was clear that a vacuum system was the only system that could be installed with the least amount of impact on the local community. The people of Saint Martin were also very happy to hear that there would be no odors from the system as well as no potential of sewer leaks from the pipes.

As the region had experienced more major storms and hurricanes in recent years it was also important that the system was resilient and would still operate during extended power outages.

Being a remote community with little experience with vacuum sewer technology the local managers and operators were very happy that Flovac installed a monitoring system throughout the network that could be watched and supported by the Flovac operations group in Europe. If there is ever a low vacuum or breakdown, Flovac’s experienced operators could assist.

The main design and installation was handled by Flovac’s project group based out of Barcelona as they had recently installed a system nearby in Canouan. This group, headed by Bruno Galindo and Francisco Rodríguez  is now supporting Saint Martin’s operators.

Grand Case St Martin

Hilton Salwa Beach Resort Qatar

The Hilton Salwa Resort is designed to become one of the largest resorts and residential projects in Qatar. Utilizing a Flovac vacuum sewer system the resort is constructed on 257 acres of land in the Salwa area. The beach resort and villas is a massive project that includes a water park, marina, dive center, cinemas, pools, a health club, spa and a considerable retail space. In addition to the rooms and suites in the main hotel building, the resort will also include two small “villages” of family villas.

Flovac was asked to design and supply a vacuum system that would be able to handle the high flows that will ultimately be handled by the Resort. The vacuum system needed to facilitate not only the hotel but also residential areas, restaurants and the marina. The client was aware of the good work which Flovac had done at Reef Island in Bahrain and was particularly impressed with the monitoring system that had been installed. The monitoring allows operators to see exactly what was happening anywhere in the network including the operation of the vacuum pump station. Mr Willem Gooren one of the founders of Flovac managed the project and was based in the Middle East for extensive periods during the projects establishment and finalization.

Smart and Safe Installation

In sandy soils, especially areas where there is a high water table vacuum systems are ideal as all of the pipework is installed at a shallow depth in the ground. A stepped profile within the pipeline design allows for some utilization of gravity while keeping the pipe shallow. Installation of vacuum mains is a lot faster than the installation of gravity sewers as there is less requirement to de-water or pre-load the land. HDPE pipe is used often when installing in hot climates and where soil conditions are unstable.

Leak Proof

The use of a Flovac system was also important to ensure that there would be no potential leaks from the system. As all vacuum pipework is under a negative pressure sewage cannot leak from the pipe in the event of a break.

The Vacuum Pump Station is one of the largest stations in the world. Housed in a dry and air conditioned environment the two large collection tanks are connected to five large Busch Mink MM 1202 vacuum pumps. Flovac has used Mink pumps since before 2005 and so has great experience in the correct set up to maximize the ability to handle the large flows required in this project.

Prestons Christchurch New Zealand

The Flovac Vacuum Pump Station was installed in 2015 to service the Prestons residential development in Marshlands Christchurch and has continued to grow with house sales in the area ahead of schedule.

Every effort has been made by the developer Ngai Tahu to ensure that this medium priced housing development for 8,000 residents is world class.

Environmentally Sensitive Development at Prestons

Right next to the vacuum pump station, the Marshland School for children aged 5-13 has been completed. When Master Planning a vacuum sewer system it is always important to consider that any flows from schools will be interrupted during school holidays and weekends. So to ensure that plenty of air is entering the system, especially close to the station the system needs to be tuned correctly or have an automatic air inlet system that can be programmed to take the change into account.The vacuum sewerage system is the ideal technology for a development like this as it can be very flexible with new additions over time and is resilient to damage from earthquakes. Unlike low pressure pump systems, the only power requirement is at the vacuum pump station, so if an earthquake interrupts power supply the vacuum sewerage network at Prestons will continue to work as there is a back up generator located at the station.

Another resilient feature of the Flovac system is that if any of the vacuum mains break or rupture during an earthquake, the negative pressure in the pipe ensures that no sewage will leak out. A low pressure pump system operates on positive pressure, so if a pipeline breaks sewage will surcharge from the pipe into the surrounding area. In an environmentally sensitive area like Prestons, that could be a disaster.

Another benefit of the vacuum sewer system is its ability to handle high flows into the collection system. A large supermarket complex is being planned in the neighbourhood complete with a Foodstuffs supermarket, cafe’s and restaurants. Already built is a large BP service station which houses a cafe and a Jetwash. The Flovac system handles the commercial premises and can handle any flows from the car washing facility.

On the right side of the BP Jetwash you can see three of the Flovac pillars that house the air vents that are required to admit air into the vacuum sewer. These are connected to three separate valve pits which are served via a splitter to handle the high flows. The pillars will also house the wireless monitoring system that is being rolled out. The monitoring system will alert operators to any valve faults or potential overflows from the pit.

The operators looking after the system have been very happy with the operational benefits and have had very few callouts. As the operators have little to no contact with sewage and have no requirements to enter the property of the residents they see real benefits relative to how the low pressure pumps have performed. Many low pressure pumps are located on the property of the resident and any maintenance often leaves residual sewage on the lawns of the residents.