HOPE SPRINGS ETERNAL AT GARDEN
New Covent Garden Market (NCGM) produces 15,000 tonnes of waste a year, which has largely been sent to a Cleanaway landfill site in Rainham.
Yet, change is imminent and the market is currently weighing up its waste management options, according to deputy general manager Robin Hope. According to a trial undertaken in 2003, only 40 per cent of the waste was free organic, with 10 per cent cardboard, 20 per cent wood and 30 per cent plastic or plastic contaminated with organic waste.
The percentages have changed slightly owing to a reduction in the use of cardboard but Hope expects the actual figure for organic waste would be in the region of 75 per cent if it were to be calculated in complete independence from the rest of the waste.
As well as the environmental drawback of landfill, the biggest incentive to find an alternative option is the skyrocketing of landfill costs, says Hope. However, ascertaining the most economically viable solution is a lengthy and complex process, he claims.
Some of the organic waste is taken up by a farm in Oxfordshire, which only incurs a transport cost of around £20 per tonne, which is considerably cheaper than the charge demanded from certain off-site composting companies, says Hope. “The only problem with this is that now spring has arrived the grass has grown and the farm isn’t taking the same degree - about half of our uncontaminated waste - and this still does not tackle the rest of the waste.”
Over the past few months, Hope has attended presentations from various composting companies in order to determine the best solution for New Covent Garden, where space is at a premium, he says. At this point in time, he is favouring the Rotocom system patented by New Zealand-based company Allertex. “It is similar to the Hot Rot system with a long partially open-top tube, a huge axle and a number of tines. The compost slowly moves down to the other end and it is aerated at the same time,” says Hope. “The difference with Allertex is that the body turns instead of the central axle, like a washing machine.”
In addition to the cost incentive, this design seems preferable for the simple reason that the compost is less likely to stick to the sides of a rotating drum, he explains. “It is a proven system which has been used in Japan and Australasia for the last 20 years.” In addition Wyvern District Council is due to implement the first big scale version of the machine in June, which Hope plans to visit.
Despite Rotocom seeming the most attractive solution, there are still various complicated issues to consider before it can be implemented, Hope says. The composition of the waste has to be determined to calculate its carbon-nitrogen mix, as well as the moisture content. If the moisture content is too high sawdust has to be added, but then has to be removed before the end of the process.
In addition, the composting is a two-stage process. “The composting has about a seven-day cycle after which it reaches the stage of maturation. This then takes about five to six weeks during which time it is still being worked on by the microbes. Before that you have a product which is not really a compost but would be considered a soil improver, although if you tried to grow something in it, it would probably kill it off.”
Lacking the space to accommodate the maturation process on-site, Hope says he would either have to sell it as an immature product or send it for maturation off-site. However, the first option raises the question of whether or not there is a market for such a product in the vicinity of central London, and who would be responsible for sales and marketing. Meanwhile the second option would bring the issue of transport costs as well as maturation costs back into focus.
As well as assessing how many cylinders would be needed, the most important factor to consider is the cost of the total on-site composting unit, Hope says. “We need to locate funding or find a partner willing to come in on the cost so that we could have a long-term pay back arrangement.”
“With the landfill charges set to rise again I don’t see any alternative but I don’t know whether it is economically viable at the moment. It may take another couple of years before landfill taxes go up again to make composting more economical,” Hope concludes. “It is a fascinating problem but it is vital that we research all of the technical elements now because if we get it wrong it could be a white elephant. We have got to make sure that if we start we will get a system that will operate correctly for us.”
MANCHESTER’S VERTICAL SOLUTION
New Smithfield market in Manchester has been operating a Vertical Composting Unit (VCU) system since July 2003, commissioned by not-for-profit community-based organisation Fairfield Materials Management (Fairfield).
The system has been expanding with the installation of additional VCUs, provided by UK distributors OrrTec, and has enabled the diversion from landfill of around 2,500 tonnes of waste. Such was the measure of Fairfield’s success that the organisation was presented with an award from the UK Composting Association.
In conjunction with the sustainable waste management system, the market introduced a cardboard bailing facility last year, which has enabled a greater level of recycling, according to Fairfield project development manager, Emma Smith.
The compost is being used by Manchester City Council (MCC) on the city’s parks and gardens, as well as being retailed to local soil processors and landscape gardeners. However, according to Smith, Fairfield is trying to determine additional end markets for the compost. “Fairfield is at the PAS 100 testing stage for the product,” she says. “PAS 100 is a BSI standard for compost administered by the Composting Association. It requires an audit trail for compost - where it came from, the temperatures reached within the composting process and an analysis of the end product.”
Smith says having the accreditation will open a range of markets for Fairfield compost - assuring customers that it contains no pathogens, has passable phytotoxicity levels and the correct carbon-nitrogen ratio, as well as other criteria.
“To support this, Fairfield has applied for funding to provide a marketing team,” she adds. “If we gain accreditation, we can use the BSI tick on our product.”
A number of changes have occurred during the last 12 months, says Smith.
For instance, the skips have been moved nearer to Smithfield’s compost corner. “They were located on the other side of the market to the Fairfield site, so it made it very difficult to persuade traders to bring waste for composting to our site,” Smith claims. “All traders had free access to the skips and this situation fostered a ‘throw it in the skip’ mentality amongst traders.”
Having the skips located near the Fairfield site means traders have to bring their waste directly to the site. “This ensures that we get enough waste to compost and that we can also divert all recyclables (plastic, cardboard, wooden boxes and pallets) from the waste stream and that the skips are filled efficiently, reducing the cost of landfill for the traders,” Smith explains.
With only three VCUs Fairfield can only process half of the fruit and vegetables delivered. However all waste is ‘split-down’ to remove cardboard, hard plastics and pallets for recycling. “This move has drastically reduced the number of skip lifts, and has meant that 99 per cent of cardboard is now recycled or composted, 99 per cent of pallets are either re-used or recycled and all hard plastic brought to the Fairfield site is now recycled,” she says.
Fairfield is now composting a minimum of six tonnes of fruit and vegetable waste daily and continually looking at the entire market to identify additional waste streams that can be diverted away from landfill.
Bureaucratic changes have also taken shape in recent months. “While this physical move has been taking place, Fairfield has tendered for and been awarded a five year contract to process the markets waste,” says Smith. “Up until now Fairfield in a sense was a research and development project in the eyes of the market. This is a massive step forward for Fairfield and a big pat on the back for the dedicated team that has worked tirelessly over the past few years.”
The European tendering process put Fairfield in direct competition with a lot of large waste companies throughout the UK. However, achieving the waste tender provides Fairfield with five-year security and would support any future attempt to apply for financial assistance as well as open the way for additional projects, Smith says. “With one tender successfully won it will increase Fairfield’s presence as a leading composter in Greater Manchester and assist in future local composting initiatives.”
The Smithfield composting system was unveiled as a work in progress and, in partnership with MCC, Fairfield has recently secured funding for the third and final phase which will see the installation of an additional three VCUs in November 2005. “This will actually double the capacity of the system, which will be able to deal with all the fruit and vegetable waste that comes off the market,” says Manchester market director, Krys Zasada.
According to Zasada, the reasons for implementing a waste management system were clear. “We decided to move in this direction after a waste audit revealed we were producing 5,500 tonnes per year which was all going to landfill, despite a large percentage being recyclable,” he says. “With this third phase we will be well on the way to achieving our target of ‘zero recycling to zero waste’ by 2008.”
Smith says Fairfield has also been working with keen supporters of the project, the Adventure Capital Fund, to be able to roll out replications of the model throughout the UK, putting into practice the expertise acquired after three-and-a-half years of hard work.
She says the organisation is keen to help other markets develop a more universally applicable system rather than simply replicate the Manchester site. “We want to identify other markets that want to utilise our knowledge, that are open to supporting and working with social enterprises and we are working with the Adventure Capital Fund on this,” she says. “We need to identify the right replication model that will support knowledge sharing. What Fairfield wasn’t prepared to do was to replicate a system straight away: we want to replicate an efficient system utilising lessons learnt over the past three and a half years.”
GLASGOW TRADERS ARE HOT TO ROT
The installation of two composting units designed by New Zealand-based company, HotRot Exports Ltd, was completed at Glasgow’s wholesale markets in February 2005.
According to Lawrence Boul, the managing director of HotRot Composting Systems, the UK venture recently formed between HotRot Exports and Milbank Industries in Essex, it has been performing well in initial tests and is due to be commissioned fully within the next couple of weeks.
The project has been partly funded by the Scottish Executive Waste Management Innovation Fund and Glasgow City Council as part of its commitment to reducing the amount of waste going to landfill sites. “We’ve been looking at the whole cycle of the fruit market, from every day produce waste, such as cabbages and lemons to cardboard boxes and pallets,” says Lynne Bryce, assistant operations manager at Glasgow market. “We are aiming to produce a unique quality compost product which we can then sell at a high level and maximise the cost efficiency.”
The council is hoping to get PAS 100 accreditation affirming the quality of the compost which should meet the requirements of a number of end markets, she says. “We would like to keep it contained locally within Scotland, for example, by returning the compost to Scottish producers.” In addition, the nutrient-rich product can be used for football pitches, and other instances of remineralisation.
Bryce says Glasgow considered the HotRot waste management system most suitable for a number of reasons. ‘It is a fairly quick process,” she says. “The waste moves through over a period of three weeks and is screened to remove oversized material after composting.”
According to Boul, the system is efficiently monitored using internet technology. “It is live on the internet which means it can be looked at remotely and all data is backed up to a main server in New Zealand,” says Boul. “The advantage of this system is that the people at Glasgow don’t have to worry. Local control is by PLC (programmable local controller) which is a very robust industrial device. The remote link is obviously vulnerable, but the data buffer is large enough that reliable data control is maintained even with intermittent internet service.”
This enables HotRot to provide a greater level of support to users like Glasgow, he claims. ‘In terms of us providing support, I can simply log in from wherever I am and see if there are any problems, and if we need to get up here to sort them out, which makes it much easier to deliver technical support.”
Since the market staff assumes responsibility for waste collection in the market and HotRot operations, the aim for Glasgow has been to feed the system with relatively clean waste and avoid problematic contaminants. As such, the waste bins are tipped onto a broad conveyor where the waste is manually checked to ensure only compostable materials pass through. It is then fed through a SEKO shredder for size reduction, which allows controlled entry to the composting units. After the three-week process of aerated composting, the material is screened on exit.
Boul says further advantages of HotRot systems include its physical appearance. “It is very low profile and not visually intrusive so there’s no problem with planning permission,” he says. “It just sits in the corner on site and the whole thing is automated so there’s no problem with people charging around the place. Also it’s quiet which is another advantage in terms of planning permission so you might say it’s a good neighbour.”
While Glasgow is the first UK wholesale market to adopt the HotRot composting system, Boul says waste management is an issue that is assuming increasing importance. He says interest is steadily increasing and he is hoping other clients will come forward once they have seen it working so well in Glasgow.
