It has been five years since Envac's underground automated vacuum waste system was launched in the UK after it was designed into Wembley City's landmark sustainable regeneration scheme. Joakim Karlsson, Envac's Regional President for the North European Countries, explains how airflow is being used to reduce lorry miles and make modern day waste collection a sustainable proposition.
Sustainability in its widest sense is a priority and people are now, more than ever, aware of their environmental impact on society. It wasn't always like this. In fact, 50 years ago waste and recycling was perceived as more of a hindrance than a priority.
Now, recycling rates are rapidly increasing and waste has now gone full circle to the point where it is now viewed as a valuable resource. So, what has changed?
Firstly, urban density is rapidly increasing in line with an expanding global population. Secondly, the importance of creating a sustainable legacy is now widely recognised throughout the world at every level of society. Waste management has never before been such a crucial component in achieving this legacy and is now an essential part of any long-term sustainability strategy.
Throughout the world, we are currently experiencing a sea change in the way in which waste is addressed from cradle to grave and the Envac system is testament to this. Incorporated into the initial design phases, Envac tackles waste management limitations inherent within densely populated residential developments.
The system works when waste inlets, one for each type of waste being collected, are placed in groups at various points throughout the site, which can range from large developments or even cover an entire city. A computer-controlled system monitors the waste levels along with programmed emptying times and when required the airflow is established, the valve opens and the waste is sucked into a pipe system. Once in the pipe network, waste is sucked at speeds of up to 70kph over distances as long as 2km. Diverting valves ensure that the waste type being collected is directed into its correct container at a central point. The waste is then automatically fed into large containers, which are then hoisted onto collection vehicles when full and taken away by the local council or waste management company.
Envac is a vehicle for environmental and social change. It increases recycling rates, reduces the amount of carbon emissions created by waste collection vehicles and makes developments and cities more appealing to their residents, businesses and visitors.
At Wembley City, for example, the system will reduce the number of waste collection lorry miles from 99,874km to 29,661km and has already increased Brent Council's recycling rates by 50%. Diesel consumption will be reduced from 33,571 litres to 9,970 litres per annum and the total kg CO2 per annum will decrease from 141,272 to 109,941.
With an underground pipe network spanning 2,500 metres at Wembley City and a single waste collection station servicing the entire development, each collection cycle lasts only a few minutes making waste collection more efficient and cost effective. More importantly, the process is mainly driven by electricity instead of diesel-powered vehicles. On completion, the system at Wembley City will remove over 400 tonnes of carbon emissions from the local environment each year and manage approximately 160 tonnes of waste on a weekly basis.
Whilst the system's ability to cut carbon emissions forms a key part of a local authority's decision to install a system, we also need to explore the wider issues currently facing recycling and waste management such as the conflict between preserving the narrow, crooked streets of historical towns and cities and the need for waste vehicles to access them.
In the medieval Spanish town of Vitoria, 35,000 residences ' 25% of Vitoria's urban population ' are now connected to the Envac system. Unlike Envac's integration into Wembley City, which has been driven by the developer's commitment to delivering 85 acres of sustainable development, Vitoria's challenge was largely down to the old infrastructure associated with historic towns and, significantly, the challenges this presents for traditional manual waste collection. The physical limitations of large waste collection trucks in narrow streets, increasing government targets and a universal acceptance that providing clean, accessible and attractive environments helps increase a city's global competitiveness, has become the backbone of Envac's latest waste management solution: the self-emptying litterbin system.
Transported by air
Launched in Mariatorget (Sweden) city centre in 2011, the system ensures that public litterbins are never overfull. Litter is placed in bins connected to and emptied by an automated collection system. Each bin contains a level sensor and once full, a valve beneath the bin opens, the litter is sucked into an underground pipe network and transported, by air, to a designated storage container.
In Mariatorget, the storage container is located underground and lifted to ground level by a hydraulic lift table for emptying. Rather than relying on manual waste collection methods, which traditionally involves multiple vehicles and people making multiple collections each day, the storage container is emptied once every 14 days. On collection day, one vehicle transports a single container to the Högdalen incinerator in southern Stockholm, where the waste is converted to energy. Importantly, Mariatorget's six-litterbin system handled over two tonnes of waste throughout last summer and processed an average of 170kg of public waste each week.
Envac is in the process of launching the system in the UK, which will represent a huge turning point for local authorities, particularly in relation to major sporting events and venues or areas where there can be a rapid influx of people, a high intake of waste in a short space of time and where waste collection vehicles struggle to gain access.
The self-emptying litterbin represents a sustainable alternative to the large numbers of collection vehicles that operate in city centres throughout the world at peak hours. If we consider that there are over 300 Local Authorities in the UK, this equates to significant levels of fuel usage and pollution ' particularly when industrial vehicles can average 3-4 mpg.
Whilst other services and utilities such as sewerage, water, drainage and now modern day telecommunications have been designed to be out of sight in the underground infrastructure, solid waste collection has remained much the same, evolving only from the dustcart to the modern day refuse vehicles we see today.
Of course, in a capricious economic climate there is the issue of financing infrastructure. Pre-recession, one of the main factors that prevented automated vacuum waste technology from becoming more commonplace in the UK was arguably an overdependence on the tried and tested formula of conventional waste collection and a reluctance to try a new approach. Now, the levels of finance available to take it forward are low and a key question that must be addressed is how can we ensure a sustainable long-term future for innovative waste management technologies long beyond the short-term economic challenges of today?
Despite being new to the UK, Envac has been in operation since 1961 when the system made its debut in a hospital in Sollefteå, Sweden. It has since completed 600 installations in 20 countries across Europe, Asia, the Middle East and North and South America covering high-profile developments including Barcelona's Olympic Village, Ferrari World, Abu Dhabi's F1 race track, and Hammarby Sjöstad, Sweden's flagship sustainable development, where it serves 8,000 residential units. Envac has now proven that it too is a tried and tested formula. In order to continue succeeding and be adopted as a natural waste management solution it has to work in partnership with a waste contractor. It can never completely replace the waste collection vehicle ' and nor should it. However, traditional waste collection and the infrastructure that has supported it for the last three centuries needs to evolve if we are to meet carbon reduction targets and create a sustainability legacy worth leaving.