Composting takes an urban twist in Manchester, explains TEG Environmental chief executive Mick Fishwick.
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Composting is usually associated with rolling stretches of the UK’s countryside but the inner city locations of Rochdale, Stockport, Trafford and Bolton are set to receive their very own composting facilities over the next few years.
“They are all within the M60, while normally they would be found in rural areas,” says TEG chief executive Mick Fishwick. As part of the Greater Manchester waste PFI project TEG Environmental is bringing its unique in vessel composting (IVC) technology to the city in a £38M contract. “Our technology is taking organic waste, food waste and green waste and turning it into compost, it is a recycling technology,” explains Fishwick.
Traditionally composting has been done by putting large piles of green waste over a huge site and turning it periodically, but IVC contains the process, in turn reducing the footprint of operations and enabling more diverse waste streams to be processed.
“Material is loaded into the top of the vessel and composted inside vertical process cages which accelerate the composting process reaching temperatures of up to 800C,” says Fishwick. In fact a total of 175,000t of material per year will be loaded in to the IVC plants producing 125,000t of compost .
After around 12 days in the cages the semi finished compost is removed from the bottom of the vessel and allowed to mature. After a further four weeks it can be sent to agricultural customers as a fertilizer and some goes to horticultural and landscaping customers and for land remediation.
“Our technology is taking organic waste, food waste and green waste and turning it into compost, it is a recycling technology.”
TEG Environmental chief executive Mick Fishwick
“The Greater Manchester plants are all fully enclosed high specification buildings with two stage scrubbers making them odour free. We are so close to local residents they had to be designed this way,” says Fishwick According to Fishwick the four sites are progressing well. The Rochdale plant began in June 2008 and is almost complete. Through Costain, TEG secured an advance works contract prior to financial close being reached in April 2009, ensuring that the programme did not slip behind as negotiations over financing continued.
Commissioning at Rochdale is complete and the IVC facility will sit alongside the already completed household waste recycling (HWRC) facility and a transfer loading station (TLS). At the second site at Bredbury near Stockport, construction began in August and concrete pours are currently underway for the base slabs. Completion is scheduled for November 2010.
Bredbury is one of the larger sites on the project housing HWRC, TLS and mechanical biological treatment (MBT) processing facilities. The HWRC is already complete, next will be the TEG IVC unit with the TLS completing in May 2010 and the MBT plant in January 2012.
Challenging ground works
The third facility in Trafford will begin in the next few months and is scheduled for completion in April 2011. The site is a standalone facility at Nash Road, as is the final IVC facility in Bolton, to be completed by October 2011.
“The main challenge has been to do with the sites themselves. A lot of the sites in the PFI are reclaimed sites that are being regenerated so the ground works were a challenge,” says Fishwick. At Rochdale in particular this is a former landfill site meaning that extensive piling, gas membranes and large raft foundations were required for the new facilities.
“When we arrived at the site we literally had a field on a closed landfill and it has been absolutely transformed.”
TEG Environmental chief executive Mick Fishwick
Costain project director John Boyd explains: “At Rochdale due to the excessive depth and variable nature (domestic and industrial waste) of the existing landfill material overlying the existing ground it was necessary to pre auger and backfill every pile location using a cased bored piling rig to ensure removal of all obstructions before installing 750mm diameter CFA piles to depths of up to 31m. This piling solution was also used under the IVC and TLS facilities.
The result, says Fishwick is a remediated and regenerated site. “When we arrived at the site we literally had a field on a closed landfill and it has been absolutely transformed.
“It has been piled, concreted, has a transfer loading station and waste recycling facility built, and all of this in the last 18 months. When you consider what the conditions were like before, these sites are really very high quality now.”
For TEG Environmental a side effect of using their technology is a boost to the local economy. “It is very pleasing as a local supplier to be supporting a prestigious project within the North West and this contract is a boost to the local economy. In TEG Environmental alone an additional 10 jobs have been created and our own subcontractors have also boosted their workforces to meet the upsurge in business,” says Fishwick.