Automating air injection during tourism bursts

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Vacuum sewer systems are highly resilient and adaptable, and the Water Corporation in Western Australia has shown how they have used technology in a clever way with the help of Flovac.

The Water Corp had a unique situation with one of their remote vacuum systems in the  town of Exmouth on Ningaloo Reef.

Regularly listed as one of the top 10 destinations in Australia, tourism pressures has led to increased flows in the town during peak tourism seasons.  In particular, this year saw the towns population increase from 3000 people to 30,000 people as it became the centre of a solar eclipse global event. This included a great video incorporating the 50th anniversary of Pink Floyds, Dark Side of the Moon 

Exmouth WA

How does any sewage system cope with massive variations in population? If you size it for peak, then sewage will not flow during the off peak periods. If there is a big increase in flow there could be overflows. Overflows in such a pristine location was not an option. Vacuum systems operate on a pressure differential which manages a complex mix of air and water. Systems are all designed for a specific air to liquid ratio. If there is too much air, then either you get very high energy costs with increased pump runs, or flows that don’t carry efficiently to the station. Too much liquid and there is a risk of overflows, or capacity issues at the rising main (force main) or treatment plant (discharge point).

Flovacs wireless monitoring system has a unique feature. The ability to alter the air to liquid ratios within the system. Programmed into the networks, different valves can be programmed to alter the mix to either increase or decrease the amount of air required along the vacuum main, changing the air liquid ratio. In dealing with seasonal issues, like Exmouth, or in areas that can get inundated by too much water via hurricanes or storm surges like Key Largo, Florida, the ability to change the air to liquid ratio becomes an important tool for managers and operators. It is fantastic that monitoring can identity infiltration, but it is essential that we give the operators the tools to handle the system when it occurs.

Rajiv Narendranathan

Last month Rajiv Narendranathan , from the Asset Management Team for the Water Corporation presented a paper at the AWA (Australian Water Association) conference in Darwin. The title was IMPROVED PERFORMANCE OF VACUUM SEWERS WITH PRESSURE MONITORING ALONG VACCUM MAINS AND PROGRAMMED AIR INJECTIION BASED ON PRESSURE TRENDS.

In his talk Rajiv said

Exmouth is approximately 1,100 Kms north of Perth and about 550Kms south-west of Karratha and the remoteness of this town makes it challenging to operate. Exmouth has a population of 2,500 people however as a tourist town the population can increase to about 6,000 people during peak holiday periods. The extreme variability in population results in unpredictable flow patterns which make the vacuum system in Exmouth near impossible to tune. Without appropriate levels of air being sucked into the system to cater for increased flows the vacuum lines are flooded and the pressures crash resulting in wastewater overflows.

Flovac AAI air injection success

The FLOVAC system monitors pressures along the Vacuum line in Exmouth and this improved visibility has enabled the system to be tuned to respond to variable flows from the catchment. The ability of this system to monitor pressures and inject air into the line appropriately has resulted in the air/liquid ratio being maintained during peak demand periods and maintain pressures throughout the vacuum line preventing wastewater overflows.

 

The project and rollout was a tremendous success and is being rolled out to numerous other projects in Western Australia. Flovac has used automated air injection systems at many projects around the world over the last twenty years. If you would like to learn more about setting up intelligent operations of your vacuum systems please let us know. Air Injection Systems

Sheltering Sewers from the Rain

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Pacific Northwest community optimizes its vacuum sewer system with cutting-edge telemetry monitoring

Full Article Click here

Making the switch from a purely septic-based wastewater handling model to a publicly owned and operated vacuum sewer system solved problems for the small community of Miles Crossing, Oregon. It also brought unforeseen inflow and infiltration issues.

Rain events revealed the need for tracking down operational overload issues in the system, which could only effectively be accomplished via automation tools. Retrofitting a monitoring system has given the district’s operators a real-time view of their system, potential sources of I&I, and a means to protect the mechanical health of this key community infrastructure investment.

Below sea level

The Miles Crossing Sanitary District is fairly new, incorporated when the community decided to shift from private septic systems to a public sewer system. The decision to convert the community — home to a population of approximately 800 — was based upon several factors:

• The town’s topography — situated on Youngs Bay, between the Youngs River and the Lewis and Clark River, is completely flat with elevation from 1 to 10 feet below sea level.

• Dikes are situated between properties to prevent them from going underwater during high tide or rain events.

• The high-water table was causing the area to experience a rapidly rising number of septic system failures, affecting groundwater quality.

The district opted for an vacuum sewer system versus a traditional gravity system. The latter would not have been feasible due to the depths required for installation combined with high-water table levels. The vacuum system implementation process, which cost the community approximately $4 million, began in 2000 and was fully in service by 2010. It comprises 372 gravity pit connections (323 of these being residential), and a single pump station that receives the entire flow from 7.25 miles of vacuum mainline. From the pump station, two 75 hp pumps move the effluent 1.75 miles under Youngs Bay to the town of  Astoria, Oregon, for treatment.

Not quite right

On normal, dry days, Miles Crossing would pump an average of 36,000 gallons per day; but during rain events, that would jump dramatically, sometimes by more than 150,000 gallons. Unlike a traditional system where I&I can exist between joints, cracks in manholes or other conveyance structures, a vacuum system is closed. Brandon Smith, pump station operator, and Carl Gifford, superintendent for the Miles Crossing Sanitary Sewer District, suspected stormwater was entering the system.

“One of the biggest challenges with a system like this is that not only do we not want the stormwater — the system simply cannot handle it indefinitely — but since we don’t handle our own treatment, we were sending extra effluent to Astoria that created extra costs,” Smith says. “Our job became finding out where that excess water was entering the system, and then correcting it.”

Gifford and Smith learned that when the system was put in place, contractors had taken each line that was tied into the property’s existing septic, severed it, and then tied it into the new vacuum system. On many properties, storm drains and gutters, as well as other forms of outside drainage, had been run into the septic system. The impact of bringing all these lines into the new vacuum system — instead of just the sanitary line — was unknown to the contractors.

These extra tie-ins created an unnecessary burden on the system and the pump station operations, so they needed to be located and removed. The task of finding the sources of these I&I culprits was labor-intensive and slow, so the district began looking for a technology solution that would assist in this discovery process.

Trial and error

As a first attempt, Gifford and Smith utilized individual pit-fire counters. Each time an individual property’s vacuum pit fired, it would trigger an analog or digital display to track the number of firings. This method proved expensive and unreliable as a measurement or pinpointing technique. As they continued to research other solutions, they were contacted by FLOVAC.

FLOVAC had been well established globally in the field of successful vacuum sewer system installations and was seeking connections in the North American market. It was able to offer Miles Crossing a telemetry system that could be connected to each vacuum pit and would deliver the detailed data the district needed to help pinpoint and mitigate its I&I issue.

Each vacuum interface valve or connection has a magnet located inside of the top section of the valve body. The FLOVAC monitoring system works by attaching a special sensor to the valve body to detect the movement of this magnet. It detects each time the valve opens and closes, as well as how long each valve stays open.

Numbers tell all

As vacuum valves tend to fire when 10 gallons of effluent have entered the sump, the volume of flows can be calculated from the number of activations. When an unusually high volume of water enters the sump, the valve will take in a larger quantity of fluid during that one cycle. The district could detect such occurrences by how long the valve stayed open. Depending on how many properties are connected to a single collection pit, they would be able to narrow down the point of infiltration to a small area.

Related: Flood Affected Sewer Systems

With the installation of the FMS, monitoring and telemetry data now lets operators see what the entire system is doing in real time. It allows them to view individual homes and their pits, and provides information on how many times it has fired, and when.

“This is especially helpful during a rain event,” Smith says. “We can see average trends for a property. For example, if a home that normally fires 30 times a day during a weather event starts showing 5,000 fires instead, we know there’s a problem and can deploy immediately to the property while the rain event is still happening to see exactly what’s taking place.”

One big discovery uncovered by monitoring involved a property with a partially collapsed lateral. Although it was functioning sufficiently to serve the home, it had been crushed in some areas. Where it ran from the home under the rock driveway, it was acting like a natural storm drain, pulling water straight from the surface into the sewer system pit. Using CCTV push cameras to inspect and document the line’s condition, the utility team was able to show the property owner the extent of the damage, its effects, and then work with them to develop a plan of action to resolve it.

Subtle adjustments

Normally, the monitoring units are connected to a transmitting antenna that sends data to the central monitoring system wirelessly. Due to the flat terrain and steel manhole covers on the pits, Miles Crossing ran conduit pipe out to a utility pedestal at the roadsides and installed the wireless telemetry equipment there. Everything works wirelessly through the latest Gateway, Bluetooth and LoRaWAN technology and is tied into the district’s SCADA system.

“We can set parameters as far as what we are asking it for, and to send us text messages when there are different alarms. This extra information is especially helpful when we are experiencing a lot of rainfall,” Smith says.

Since its installation, the system has required minimal maintenance. A yearly visual inspection of each valve pit is typically all that has been needed. Rare mishaps can occur, but — due to the very nature of the sealed system’s construction — if things happen, the pumping equipment operation and vacuum attributes make pinpointing issues quick.

Moving forward

Nearly 60{f2ac4d1e1d40dc2e2d9280a1dfa90d854b2d8c80eba743affa37fc4ce2e16def} of the system has been fitted with the telemetry monitoring system, and phase two of the project, a complete system rollout, is commencing shortly.

“By retrofitting the entire system with the FMS, we will know when there’s a problem before the homeowner does,” Gifford says. The monitoring system also provides a high-level float that can alert the operators when a pit begins to have an issue. Now Gifford and Smith can be more proactive versus reactive in keeping the system in peak operating status, while cutting down on field time and hunting down overflows.

With just a little more than half the system being monitored, the district has already seen significant savings in treatment costs, Gifford says.

“The vacuum system was a great solution for this community and now with the telemetry tools, we will have a sustainable, high-performing and affordable sanitary system for our district for generations to come.”

Related: Information about Flovacs Monitoring System

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.

Growing Pains or Growing Old Pains – What best describes your old gravity sewer?

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What happens when your sewerage network gets too old? Your old clay pipes have cracked or are filled with roots, every time it rains it seems like its a direct line from the clouds to the Treatment Plant. People in the community start asking why you are spending a load of money on treating rainwater instead of just sewerage.

If you are part of a coastal community it could be worse, your old broken  pipes could be letting seawater into the system every time there is a high tide or major storm. Salt water can cause major problems at the Treatment Plant. For communities like Miami Beach who get storm surges flooding their sewers and closing their beach on an increasingly regular basis it can cause major economic and health risks. Santa Pola in the Alicante area of Spain found that the impact of global warming and rising sea levels caused a complete failure of their old sewer system.

The town of Santa Pola with over 10,000 homes replaced their whole gravity sewer system with a Flovac vacuum sewerage system. As vacuum mains are laid in shallow trenches it was possible to skirt around, above and below exiting infrastructure and eventually replace the network. You can read more about that project here.

It could be that the old gravity sewer system with large heavy pipes just wasn’t suited to the ground conditions that are often found near the coast or in swampy area’s and that over time they no longer have the correct grade to remove the sewage or have pipes that continually break allowing ground water into the system as well as blockages. This occurred at Hope Island on Queensland’s famous Gold Coast.  Gold Coast Council have developed a Master Plan and slowly replaced a number of area’s with vacuum sewers. When the original gravity sewer was laid, there was no choice, developers were racing to put up houses and council at that stage had no experience with vacuum sewers and so deep gravity mains were installed. Almost immediately problems were noticed as the ground subsided in different area’s. Sewage backed up in pipes and was unable to flow as the grades first allowed for in the networks were no longer the same.

When looking at upgrading a gravity sewer, pipe relining can be an option, but in many cases this becomes an ongoing expensive option and be too difficult in a large network. Some utilities just look to replace the old pipework, but in most communities this is just not practical. This could mean uprooted gardens, roads out of use for a number of months, noise, dust and a huge cost.

For many communities it is the size of the town that has changed dramatically over the years. In most cases this has meant an increase in the population as people move from the city to the coast. Developers move into the fringes of the town. Planning regulations change allowing for sub dividing of the old large land blocks or height and density changes. This puts pressure on existing sewers that are already not coping due to age and lack of maintenance. This has happened, not only in small coastal towns but in larger developed cities like Abu Dhabi and New Delhi. Vacuum sewers can be used to supplement the towns aging sewer system, loads can be taken off the main system by a series of collection pits and shallow pipework.

Flovac vacuum sewers have shown time and again, their versatility. This means either their ability to handle density changes or climate changes. It might even mean changes in ground conditions as happened in Christchurch New Zealand when they suffered from a terrible earthquake. The old gravity sewers in the city and surrounding suburbs broke and left residents with no service for months. Vacuum sewers have now replaced a large portion of the gravity sewers in Christchurch and although difficult has proved to be a better long term  solution for the residents and operators. Christchurch systems

Vacuum sewers should not be looked at as the only solution in many of these towns. In some cases a combination of grinder pumps, gravity and vacuum is going to be the better result for the community. Whether the problem is growing pains, or growing old pains a vacuum solution might offer the versatility that you need.

First FLOVAC vacuum sewer project in Norway at the innovative Center for Animal Research

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NORWAY WELCOMES FLOVAC VACUUM SEWERAGE SYSTEMS

Flovac’s Antje Adler on right

The Innovation team from Flovac’s German Unit under the management of Antje Adler has been appointed by Norway’s leading engineering design firm STATSBYGG to supply a Flovac vacuum sewerage system for inclusion in the new Center for Animal Research at Campus Ås. Based outside of Oslo, Campus Ås will become Norway’s largest interdisciplinary academic Center for the environmental and life sciences and for landscape architecture.

The Center is affiliated with the Norwegian Environment and Biological Sciences University, NMBU and will be the national plant for research and education in livestock production in Norway. Ås gård has become an environmentally friendly facility with a great focus on animal welfare.

There are space for 1200 animals on Ås farm, which consists of five buildings totaling 16,400 square meters . Small sheep (sheep and goats) have been accommodated in an airy barn of 1630 sqm, while the pigs have got their own 1740 sqm building with warmth in the floor. The entire livestock unit of 7140 sqm is equipped with two fully automatic milking robots, an advanced robot that can supply feed to the cows throughout the day.

As disease control and prevention is of utmost importance, the Flovac system was chosen to ensure that any waste from the animals is collected in a safe way. A Flovac pump station which generates the vacuum pressure in the wastewater collection network is situated remotely from the animals with flexible pipe installed underneath the livestock units. All waste is collected via floor drains throughout the facility. Flovac valves are housed in the floor drains and operate pneumatically with no need for an electrical connection. This reduces the carbon footprint of the facility. To ensure as little disruption as possible for the livestock all valves are remotely monitored and crucial data can be collected by the management team.

The STATSBYGG design group chose to work with Flovac after a close study of the Veterinary University of Hanover’s epidemic disease prevention unit’s use of the Flovac vacuum sewerage system installed in 2015. They cited the speed of installation, flexibility and that there had been virtually no operational issues and no contamination occurrences as the reason for choosing Flovac.

Information about the Hanover project can be read here.

A number of tests on the vacuum system were done, including a leakage test to show that if the vacuum mains were broken in anyway there would still be no blockage. A video of that test is available here if you would like to watch it. Flovac Leakage Test

If you have a specific wastewater problem that needs some out-of-the-box thinking, then please contact us and we can see if there is some way in which a Flovac vacuum sewerage system might be the best solution for you.

Flovac System handles Radioactive Waste at Hospital

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Flovac’s engineering group in Poland, working in conjunction with The Medical University in Bialystok have developed a unique solution that has broad applications for Hospitals around the world.

The problem that many hospitals face, particularly those focused on cancer wards is the radioactive wastewater that is held for long periods of time in storage tanks. The use of vacuum toilets in the cancer wards reduces the amount of water flushing to 1 litre per flush reducing the water usage and the space required for storage tanks.

VS and storage tanks

Another main problem that the Flovac engineers resolved was in how to get the radioactive waste from the cancer treatment rooms to to storage tanks located in the basement. An initial gravity design by the hospital proved difficult as not only were the treatment rooms spread out throughout the hospital there was also no room to fit the gravity pipes due to congested corridors already taken up with other pipework and power cables.

The Flovac system that was installed used small diameter PVC pipe with glued joints. The small slope that was required made it easy to avoid obstacles and helped get around difficult area’s. Small grey water collection sumps and vacuum toilets ensured that no digging through floors needed to be done. The vacuum pump station which generates the vacuum energy throughout the pipe network was housed in the basement right next to the storage tanks. This meant that no valuable space was taken up with sewage infrastructure. The Chancellor of the University was particularly happy with the speed of construction and the limited impact the installation had on the working of the hospital.

One of the most important elements that the Flovac system delivered was the security in knowing that no radioactive materials could leak out of the pipework anywhere else within the hospital. As the vacuum pipework is always under negative pressure if a break in the pipe occured air would be sucked into the pipe and no wastewater could exit. As more vacuum would be required at this point the operator would be immediately notified and repairs made.

rotator_4

A number of hospitals in Poland, working in conjunction with the University are planning to utilise this technology.

If you would like more information on this please contact [email protected]

 

 

Center for Preventing Disease Epidemics in Animals using a Flovac System

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The highly reputed Veterinary University of Hanover is, among others, engaged in the Pathology and Epidemiology of livestock, especially domestic cattle and pigs. After 2.5 years of construction time, the first part of the new research Center for Emerging Infections and Zoonoses (RIZ), with a total investment of 37 mill. Euro was opened in the end of 2014. The second part of the complex, with total 2000 sqm and 40 laboratories will open beginning of 2015.

UntitledFor the need of a safe dewatering of the potential contaminated wastewater from the test fields and laboratories, a vacuum sewer system was chosen. A vacuum system is the first choice for such a demand, due to the fact that in any case of leakage no liquids can emerge.

Totally 19 collection units, with FLOVAC  3” vacuum valves, are installed in the different stables and 85 wash bowls are dewatered with FLOVAC vacuum dewatering boxes. Also special designed vacuum floor drains are built in.  In addition FLOVAC stainless steel vacuum toilets are used. The vacuum piping, with a total lengths of 800 m is installed in the cellar of the building.

A small vacuum station, for generating the needed vacuum, completes the system. Only this component of the system needs power supply, all other components are operated pneumatically by vacuum.

Under the aspect of epidemics protection, a vacuum sewer system is the best opportunity for transporting waste water in the research center.

Flovac Train Project Canada

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Flovac has just completed its first train extraction system in Canada at the Willowbrook Maintenance facilities for the Go Transit group in Toronto.

 

As trains come into the yard maintenance crews can hook up a vacuum hose via a fitting to the trains sewage holding tanks. The tank is evacuated via a push button control on the Flovac Valve. Sewage goes via a vacuum main back to a series of vacuum pumps and then discharged to the gravity network.

The whole system has monitoring so that operators can see exactly what is happening within the facility to control the amount of flow that is occurring at any one time.

The management team and operators at Willowbrook were particularly impressed with the speed of the evacuation of the trains as the process took a matter of seconds rather than the extensive delays that they have previously had. This meant that money was saved in labour costs but more importantly in the amount of time that it took to get the trains back into service.

Flovac has now installed extraction systems for a number of  clients in particular for the Deutsche Bahn’s ICE network, including systems in Frankfurt, Cologne and Dusseldorf.

Projects have also been done for Irish Rail, SBB Swiss, RENFE Spain, OBB Austria and France SNCF.

The system can handle either single or multiple suction points even up to 60 extraction points.