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Flovac Collection Pits are Preferred by Vacuum Sewer Installers

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Many Contractors find installing vacuum sewers much easier to install than traditional gravity sewers and low-pressure pumping systems.

Vacuum sewers are installed in shallow trenches and have an easy connection point at a property boundary for homeowners to connect up to. Gravity flow from a number of houses, usually between 2 and 6, depending on the flow rate from the property, flows to a collection pit.

The Collection Pit houses the vacuum valve which provides a pneumatic interface between the gravity side of the network and the vacuum, negative pressure, side of the network.

In older systems, concrete manholes were used as well as fibreglass collection pits. Both have had issues with I&I (Infiltration and Inflow) becoming an increasing problem. This has been picked up very well with Flovacs monitoring system. 

The Flovac collection pit has been designed by operators and is built under ISo conditions to a standard for collection pits using PE materials.

Have a look around one of our collection pits recently being installed in Florida.

The first and most applauded by operators is the shut-off valve for testing and service work on the pit. As Flovac is a world leader in vacuum technology, this is now the standard in many countries. The shut-off valve is an essential tool to keep your team safe.

The vacuum stub out is welded to the side of the pit, eliminating inflow to the valve pit and ensuring alignment with the valve is 100{f2ac4d1e1d40dc2e2d9280a1dfa90d854b2d8c80eba743affa37fc4ce2e16def} every time. Thus, reducing instillation errors and eliminating no-hub couplings coming off. Additionally, if the valve closes on water, creating a water hammer, all the energy is suppressed.

Flovac uses either H20 rated hinged or HDPE lids; both seal the valve pit from water getting in. Keeping the upper valve pit dry protects your valve and controller and eliminates operators from having to fish in stagnant water during serving. Additionally, the sump of the valve pit has a 30{f2ac4d1e1d40dc2e2d9280a1dfa90d854b2d8c80eba743affa37fc4ce2e16def} larger holding capacity on average, which is just one of our design philosophies to ensure adequate response time during an emergency.

Lastly, the feedback we receive from contractors includes how easy the pit is to set and connect. With many more connection points, clock position is not an issue.

Hard to believe, but the highest praise from contractors is that our valve pit has lifting lugs, a crucial must-have.

You can read more about our Collection Pit Here

My Vacuum Pumps are Due for an Upgrade – What Next ?

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When a vacuum sewer system was planned in your area, there was probably an options study done showing whole of life costs. There was an expectation that over the life of the system (100 years) there would be items that would wear out and need replacing. Just as there would be components that would needs parts replaced through normal maintenance. (Asset Life)

For the rotary vane vacuum pumps, that would mean oil and filter changes. According to the pump manuals you would expect to do a fairly extensive motor overhaul at year 5 with a possible replacement at year 15. Through good care, we have seen many vacuum pumps have their lives extended considerably. That has been especially true of liquid ring pumps.

Many of the systems built prior to 1996 used liquid ring pumps (the days when water wasn’t considered a scarce resource). Since then, there has been a mixture of mainly rotary vane pumps for larger systems with smaller systems using dry running claw pumps. There have been a few outlier pumps like oil sealed screw pumps and even some rotary lobe pumps.

The vacuum pumps in your system would have been sized based on an air to liquid calculation based on the length of vacuum mains and the volume of the mains. Operationally we always look to the amount of air it takes to move the liquid through the system. A well run fully developed system should run at about an 8 to 1, or 10 to 1 air to liquid ratio. We know that if that creeps up to 30 to 1 that there is too much air in the system, and it should be tuned. A high rate like that would suggest that the vacuum pumps would be running far more than they need to. If the ratio though was lower at about 4 to 1 or 6 to 1, we would know there was too much water relative to air. This might mean the discharge pumps are running longer than they should, relative to the vacuum pumps. This might be due to I&I (infiltration and inflow) or higher flows than expected in the catchment. (Ask us for the calculation sheet for the air to liquid ratio)

With a good air to liquid ratio, we would expect the vacuum pumps to run at about 6 to 8 hours per day, in total, in a fully developed system. If your pumps are running longer than that you should check your air to liquid ratio to see what is impacting your system.

Two of the biggest mistakes that we commonly see when utilities are looking to upgrade their pumps is

  • Increasing the size of the pumps as the current run time is excessively long
  • Changing from a oil lubricated pump (R5) to a dry pump (Mink) to reduce operational costs.

Increasing the size of your pumps

This might be a great idea if done for the right reason. Talk to your engineers. If you can increase capacity at the station maybe that will allow you to accept more flows from subdivisions, new areas, higher density (more revenue).

If though you are only increasing the size because your pumps are running a long time then you need to fix the problem first. Why are the pumps running so long? Is the system tuned correctly? Are there leaks in the valves or pipework? Oversized pumps can increase the problems in a network by creating more leaks.

Once the system is tight and you have an accurate idea of your air to liquid ratio then you can make a more informed decision.

Changing to Mink Pumps

If the change is because you are using too much oil and too many filters, then it would suggest that your pump run hours are too long and you should take the steps mentioned above.

In small systems Mink pumps and their equivalent have improved substantially but in large systems where you are changing over from R5 630 pumps or their equivalent there are a number of downsides that utilities are now discovering.

In the larger sizes the Mink pumps run a lot hotter and potentially noisier. The heat has an impact on pipe materials in the station, venting of the station, and will badly affect odour control measures.

On larger systems there is a limit to the depth of vacuum that these type of pumps will achieve and often the result is an increase in energy use and pump run hours.

Some utilities have also tried the addition of variable speed drives in their pumps as a way of increasing vacuum in the lines and decreasing line flooding. The speed is often varied due to the amount of vacuum pressure in the lines or at the end. It is rare to see this used in wet/sewer type systems and is more common in dry/food processing applications. As vacuum sewers are based on a ratio of air to liquid, the use of a VSD disguises problems in the system and can ultimately increase problems in the networks.

Upgrading of your vacuum pumps is inevitable – we can help you with finding the right solution for your system

Call our Engineering or Operations Group to organise the following as a first step.

  • System Audit To correctly size the vacuum pumps an analysis of the air to liquid ratio is needed. The system needs to be air tight to do this. If there are leaking vacuum valves, due to old age, air leaks in the pump station or elsewhere, these need to be fixed prior to any upgrade as any larger or new vacuum pumps could make these harder to find and just lead to higher energy costs and high oil use. An Audit will check the current state of your system; give you an understanding of what will be required to accomplish the outcomes you want
  • Capacity Audit What was the system designed to handle, what can it potentially handle for the next 15 years.

To read more about Upgrades Click Here

Interview with a Utility Ops Team Leader

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A recent interview with team leader David Parkinson of Byron Shire Council gives insights into their vacuum sewer system and just how installing a monitoring system can have time saving and financial benefits to councils.

The Byron Bay community on the north eastern coast of New South Wales is listed as one of the top ten destinations in Australia for tourists from around the world. Its pristine beaches and popular cafes and restaurants ensured that even through covid, domestic tourism has kept the area as busy as usual.

A vacuum system was installed in 1993 in a section of Byron Bay which encompasses light industrial, commercial and residential users. Increasingly heavy rainfalls on the coast revealed the need to pinpoint operational overload issues in the system, this could only be accomplished via the use of automation tools. Retrofitting their system with a monitoring system has given the Council operators a better overview of their systems operation, and a means to protect the mechanical health of this key community infrastructure investment.

A recent interview with Team leader Dave Parkinson of Byron Bay Council gives further insight into just how installing an electronic monitoring system can have time saving and financial benefits to councils.

  1. What has been your role at Byron Bay Council what has been your involvement in implementing the Flovac Sewerage System there and the monitoring system?

“Essentially my job as Team Leader was to oversee the install of the telemetry pillars to the 89 pits. Also overseeing the installation of antennae to receive telemetry from the pits, and also the roll-out of training and instructions on installation to staff. I deliver an overview to new staff on the system and how it works”.

  1. How long has your Flovac system and the monitoring devices been installed?

“The Flovac system commenced being installed in 1993. The monitoring system in 2020”.

  1. How does your monitoring system work?

“It’s a great system which has empowered staff to monitor the system in operation using their iPads and mobiles on a daily basis. They are able to fix and rectify faults quickly and seamlessly”.

Saving Operational Hours

  1. What, in your opinion is the main advantage of the Flovac system itself, and in particular their monitoring system?

“The main advantage is in time saving after hours. Staff can monitor the issue before leaving home and drive straight to the pinpointed problem pit or pits”.

  1. Is the monitoring device a time and cost saving system?

“Yes, it’s benefits are both; in time and cost savings for operations staff. For example, when it’s extreme weather like our recent big storm event on the East Coast of NSW you can locate the problem much quicker, lessening the time spent in poor weather/working conditions for our teams”.

  1. Would you recommend it to other councils with similar low-lying coastal terrain as you have?

“Absolutely if you’re going to install this type of system, we would recommend you have the monitoring system on it. We asked our maintenance staff to assist us with the choice of systems when we needed to replace the old one and the Flovac system was selected because of the whole package that was offered. After five years we gradually moved over to this system”.

  1.  How did you hear about this system?

“Flovac approached Council when we were deciding to replace the ageing valves. We were impressed by the ongoing support offered by John Radinoff and his team when he presented the Flovac system’s many benefits to the Management and Operational teams”.

  1. Do Flovac provide good operational support when you need it?

“Yes, they have followed through with their ongoing support 24/7. Flovac also offered us the first monitoring service. The company is innovative and developed it to assist us in more efficient delivery of services to our residents”.

  1. Has the addition of a monitoring system helped you operationally? If so, in what way?

“Yes, absolutely it allows the operational team guys to take control of the system themselves. There are definitely long-term savings which we should recoup within a five-to-seven-year period”.

  1. Would you suggest that any new vacuum system automatically should have monitoring built in from the start?

“For sure, it’s helped us considerably”.

  1. Do you prefer having a vacuum system, or would you prefer a low-pressure pump system and why?

“We have both systems in Byron, each has their own specific purpose”.

  1. Would you like to add anything that is not covered in the questions?

“As the monitoring system is more refined we will be able to better assess the current Flovac system for even more benefits”.

 

To read how the monitoring system saved Byron’s vacuum system during major flooding earlier in the year please Click Here

For more information about Flovac’s Wireless monitoring system Click Here

Flovac’s First Project in Botswana

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A Flovac vacuum sewerage system has been installed at the site of one of Africa’s most important infrastructure projects, funded by the African Development Fund.

Kazungula Bridge Connecting Countries

The Kazungula Bridge project which is connecting Zambia and Botswana over the Zambezi River will be a 40{1deaea03afbf3f3fb2d45caffee157f5a0ec73dd837732cad8f5061c47eb75db} boost to the GDP of the countries involved as it opens up the regions for trade all the way to the port at Durban.

The Kazungula Bridge is located at the only area in the world where 4 countries meet together. Zambia, Botswana, Namibia and Zimbabwe. One of the Seven Natural Wonders of the World, the Victoria Falls is located a short 1 hour drive from the project.

As the new Bridge opens up trade and tourism between the four countries it was necessary to set up a new border customs and immigration complex. Zhong Gan, an experienced International engineering and construction company based in Botswana, has done numerous projects for the World Bank and Botswana Government and decided to use a Flovac vacuum sewerage system on this project which services this complex.

Justin Peng the project director of Zhong Gan chose a vacuum sewer as a value engineering proposal to the client as there was a high water table which prevented deep excavations required by the original gravity system proposed. Ensuring that no sewage could overflow to the Zambezi River was also important as the area is home to elephants and others in Africas Big 5.

Installing a Flovac Collection Pit and Valve

Smart Vacuum Sewer System

The Flovac system is the first smart sewer system installed in Botswana which allows the operator to have a complete system overview. The smart system allows the operator to look at the performance of each vacuum valve in the system and independently alert operators to any potential problems.

Mr Peng chose Flovac due to the operator friendly nature of the design and equipment and the overwhelming positive feedback from prior installations that his team visited. The Water Utilities Corporation approved the system who were extremely pleased by the advancement in technology and ease of maintenance compared to other systems that had been installed in Botswana and Southern Africa.

The Flovac Team worked very closely with our local representatives Multi Waste Pty Limited headed by Andrew Davies. Multi Waste are a large domestic company , experts in water, wastewater and energy in Botswana and Southern Africa. Multi waste set up a fabrication plant for the Flovac pits and handled all assembly of the system at their head office in Gaborone prior to delivery to site.

The Multi Waste team will operate and maintain the system for the time being with support from the Flovac International Operations Group via the monitoring system.

 

The Flovac and Multi Waste Design and Install team

 

 

 

 

Why Hilton Resorts chose a Flovac Vacuum Sewerage System

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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. (Hilton Hotels  announcement)

Hilton Salwa Beach Resort and 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 (Read Here) 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.

 

 

 

 

Helping Hurricane affected communities in the Caribbean

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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

Gratulacje Flovac Polska for a new Septic Tank Replacement Scheme

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Flovac Polska, the largest designer and supplier of vacuum sewerage systems in Poland has just completed providing a vacuum sewer system for the small rural town of Zakościele. The community is a ribbon development along the Pilica River.

The small town with about 150 houses is located approximately 60 km south east of  Łódź. Some of the houses are located alongside the river and above the road sloping down towards the river. Between the river and the main road, where most of the houses are located, flooding has become a regular occurrence. It has become a health issue with septic tanks overflowing when the flooding occurs.

At first a tender came out for  a gravity system with a number of pump stations located along the rivers edge. When our colleagues from Flovac Polska contacted the town and contractor (designer) about the benefits of a vacuum system in this location, they were very unsure as they had never heard of vacuum system.

After a whole of life costing analysis and discussions with the contractor about the capital costs it was clearly shown that the vacuum system would be a much cheaper option. More importantly a Flovac system was seen as a much better system to install in an area where flooding was a problem.

Read here about how the Flovac Valve can operate under water

Another major benefit of the system is that it is fully monitored, so all of the collection pits and pump station sends data to the central control system and the operators.

This includes a high level alarm and an alarm that warns of any possible infiltration occurring. All of the monitoring equipment is rated at IP68 so that it can operate under water.

This is shown here on a video taken of one of the Flovac valves operating under water with the MZA monitoring device attached. SEE HERE

Poland has become one of largest countries in the world using vacuum sewerage systems and Flovac Polska has designed and installed more than 60 systems, nearly all of which have been septic tank replacement schemes funded by the European Union.

Upgrading your Vacuum Pump Station

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The Vacuum Sewerage Industry is now 50 years old and for a variety of reasons some of the systems infrastructure will need to be replaced or upgraded. It could well be a move away from old liquid ring pumps. It could be that some of the equipment has just come to the end of its expected life. You may have inherited assets that were never looked after as per the suppliers manuals.

Hopefully you have a station that was designed with the future change out of equipment in mind. Large doors and a cranes to get pumps out of the building. A roof that can be dismantled without too much problem to get the tank out and replaced. Fortunately the building was designed so that upgrades or refurbishment could occur. A new stainless steel tank was installed. An upgrade can give the utility a chance to look carefully at the catchment area with fresh eyes. Have the daily household flow rates gone down, have you installed new monitoring systems that have sorted out any infiltration.

Are there more houses or another developer that you could now accept into your catchment if the pumps were slightly larger? The Flovac Engineering Group is often asked for advise on the upgrading of a vacuum pump station and as the group has designed more than 300 stations and probably designed the one you are now upgrading, they would be the best people to speak to.

The Flovac Operations Group is the next point of call. What changes have there been to suppliers equipment, what lessons have been learned from hundreds of systems around the world. Are there changes to health and safety regulations. What impact will there be on power use, ventilation and odor. The most important aspect is what is your plan to upgrade a system that is now live without major problems.

The operations group have been involved with the installation of more than 300 vacuum stations and the upgrade of more than 50 stations. Flovac can supply containerized vacuum stations to support the upgrade.

For a more in-depth look at what is required when a vacuum pump station is upgraded there are more details here or call our engineering or operations groups.

Versatility for Developers

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A “Plug N Play” Temporary Solution.

Installing infrastructure at the early stages of a residential housing development can often disrupt the staging process and the cash flow of the project. Vacuum sewerage systems can make it easier.

At Flovac, our engineers have used deployable engineering solutions that will be incorporated into long term projects.

The town of Clevedon in Auckland New Zealand is finally beginning the process of eradicating septic tanks which have been causing environmental problems and will install a new Flovac vacuum sewerage system. Growth in the town had been on hold due to the lack of a proper municipal sewerage system. This has impacted on the restaurants and commercial premises and the increased demand on housing which is just a short drive to Auckland City.

Gravity sewers were looked at for the area, but a very high water table made that a very expensive and disruptive alternative. Low pressure Grinder pumps were also looked at but with an ultimate population of more than 6,000 people costs made that prohibitive. There were also other downsides with looking at grinder pumps where the local utility has had some terrible experiences. An increasing number of severe storms meant that power outages left communities with no access to sewer services. Also off sewage during low flow periods put added pressure onto Treatment Plants. The main issue was also the reluctance of the community in having sewerage infrastructure on their properties which would need to be accessed whenever problems arose.

The proposed vacuum sewer system will require only a single vacuum pump station and all sewage infrastructure will be outside the property boundaries. There will also be far less impact on residents as installation can be a lot faster than a gravity installation as all pipework will be shallow in the ground and so less de-watering will be required.

Watercare who are the water and wastewater service provider for the greater Auckland area is leading the project and has had a lot of experience with the successful Flovac vacuum sewerage system at the town of Kawakawa Bay which has won a number of engineering and environmental awards. members of the project team have also visited the successful projects that were installed in Christchurch NZ which replaced systems impacted by large earthquakes. Auckland is also in an earthquake zone, making vacuum systems an even better solution.

As the township of Clevedon connects up to the sewer network a number of new residential developments will also be built and will connect to the system. The vacuum sewerage system is versatile enough to cope with developers adding on new houses as they are built over the coming 10-15 years.

As there are multiple developers involved in the project, the timing of infrastructure installation can be difficult. What roads need to be built first, which group of houses need to be serviced first.

One well know developer with a small block of 26 houses positioned at the very end of the catchment wanted to develop their land well ahead of the infrastructure being ready for connection. As it is a major project it will take over two years to complete and possibly longer before the pipework reaches all the way to the end of the catchment. Working with Flovacs engineers an interim solution was proposed and Watercare was flexible enough to allow the developer the opportunity of utilising short term infrastructure.

Flovac’s deployable sewerage systems have been used in a variety of projects around the world, including at the London Olympics. You can see details of the projects here.

The developer installed the vacuum mains and house connections as well as the Flovac collection pits. A plug and play containerized vacuum pump station was positioned next to a temporary treatment plant and the system was connected up. Once houses are built, local plumbers can connect to the vacuum pits. The system will be operated and maintained by a local operator with support from Flovac. As the station and all of the collection pits have wireless monitoring, Flovac’s operations center in Sydney Australia can provide 24 hour support.

When the time comes, the deployable system can be moved on to the next project and the vacuum mains connected up to the main Clevedon project mains and vacuum pump station 4 km away. The developer has spent a minimal amount of money which allowed them to start selling houses significantly faster than traditional methods would have allowed for.

Water Supply and Sewerage in the 21st Century

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The City of Marki in Poland, north east of Warsaw and Wodociag Marecki the Utility Company that maintains the water and sewerage systems in Marki City are quite unique.

There is a very close relationship between the utility, the City and Warsaw University of Technology. Over the last ten years they have done a number of concepts, designs and installations using a number of different technologies for specific sight conditions throughout their area. These have included vacuum sewers, gravity sewers, pressure systems and even domestic on-site treatment plants.

Prior to this initiative the City had relied on septic tanks so they wanted to ensure that they used the right technology for the right area and community. What has been tremendous about this effort is the city’s willingness to share their experiences with others around the country. Flovac applauds their efforts in this field and have been very happy to support them.

On a periodic basis seminars have been held to discuss their findings, the most recent of which was recently held in Zegrze near Warsaw.  The seminar was titled (Water Supply and Sewerage in the 21st century) and included representatives from a number of local authorities and utilities from the north east of Poland. Experts were invited to talk on different subjects.

On Vacuum Sewerage Systems the speakers were:

Prof. Dr hab. inż. (prof. PhD Eng) Zbigniew Heidrich – Politechnika Warszawska (Warsaw Univerity of Technology)

Dr inż. (PhD Eng) Marek Kalenik – Szkoła Główna Gospodarstwa Wiejskiego (Warsaw University of Life Science)

Dr inż.  (PhD Eng) Jacek Sobesto – Flovac Polska sp. z o.o.

Dr.inż. (PhD Eng) Grzegorz Stańko – Wodociąg Marecki sp. z o.o.

Dr Jacek Sobesto of Flovac Polska

One of the largest Flovac systems in Poland is based in the City of Marki and has over 800 Flovac valves connecting residents to the vacuum sewer. It has proved to be easy to maintain and well accepted by the community.

Vacuum Pump Station in Marki

Inside the Vacuum Pump Station in Marki