Suffolk: The burning issue of what to do with our waste

IMAGINE a society with no more rubbish. It’s the vision of those behind a major energy-from-waste facility being built on the outskirts of Ipswich at Great Blakenham.

It’s an impressive construction project in terms of its scale, and the design, with a modernistic structure over a lake created by the designers of the Eden Project, Grimshaw, is set to give it more than just a functional status. A visitor centre has been included within the scheme, in an attempt to engage the public and redefine our relationship with what we throw away.

More than 20 local firms have so far been involved in the £180million building project, providing goods and services worth around £2m.

The work started in May 2012 following the demolition of the old highways depot which once stood on the site.

In February, the chimneys for the furnace, which will burn all our household waste left after recycling, was completed ahead of schedule, and by the summer of next year, the first of this waste should arrive on site to “test drive” the furnace, which is set to become fully operational in December 2014.

Suffolk County Council decided on the project some years ago, after grappling for some time with the headache of how to minimise the amount of waste being sent to landfill sites. Mounting costs and ever-increasing legislation meant it had to act, and its solution was an energy-from-waste plant which will be run by SITA, a waste management company and subsidiary of French group Suez Environnement, part of GDF (Gaz de France) Suez.

According to Suffolk County Council, the plant should work out at least £350million cheaper over its projected 25-year life, compared to continuing to dump our waste in landfill.

In addition, if the plant operates as it has in other areas, it should generate around £1m a year for the local economy, and there will be environmental benefits.

A series of contractors have been helping to turn this aspiration into reality, including Lagan Construction, which has been responsible for the main building work. The principal contractor on site has now switched from Lagan to CNIM, which will provide the process equipment.

Once operational, the site will take household and some business waste from across Suffolk and convert it into enough electricity for 30,000 homes.

Overseeing the project is Cliff Matthews, regional manager for energy-from-waste with SITA UK.

He explains how the trucks laden with waste will arrive on site and tip their loads into a bunker, where a grabber will mix the waste up to ensure that it burns as evenly as possible. It will head to a furnace where it will be burnt down, leaving ash. The smoke and steam created heads through a series of filters to prevent poisons from entering the atmosphere before it is emitted through the tall chimney stack, around 81metres in height.

Meanwhile, the ash heads along conveyor belts, where metal is removed using a magnet and sent for recycling. The bottom ash remaining can be used as an aggregate for building.

The structure itself is held up with several hundred foundation piles, some of which are 13metres deep, and reinforced concrete, and the main building will, when finished, be just over 37metres tall at its highest point.

As a waste management company, SITA deals with everything from bin services to landfill, plastic waste, diesel waste and merfs (materials reclamation facilities). It also deals in scrap metal, and landfill power generation.

Cliff has worked for the company for the past six years and was national operations manager for landfill power generation, working across every SITA landfill site.

SITA has experience in energy-from-waste plants in the UK, and runs one in the Tees Valley in Middlesbrough, which is 15 years old, a 10-year-old plant at Kirklees in Huddersfield and another on the Isle of Man which is seven years old.

“We have got 57, including in the UK, in Europe. About 43 of these are in France. I know we are building in Poland, he says.

“We are building this one, another at Tees Valley and another in Cornwall.”

Local authorities are turning to companies like SITA for very clear reasons, both environmental and financial.

“Landfill tax currently is £64 a tonne and it has been going up in £8 increments year on year so this year it will be £72 and the year after £80 so there’s an increasing pressure on landfill,” explains Cliff.

“That’s before you even pay the landfill operator. At that sort of level, alternatives become economic, which is why around the country around 20 energy-from-waste plants are being built.”

In Suffolk, the need to do something was becoming increasingly pressing when councillors decided to opt for an energy-from-waste plant.

Space for landfill was running out, national recycling targets were going up, and economically it was getting more and more expensive because of spiralling landfill charges.

“They needed to find an alternative to landfill that was cheaper and greener and that’s what they felt energy from waste provided for them,” says Manda Henry, SITA communications officer.

On all the costings, this solution worked out cheaper in the long run. SITA was awarded the contract to build the incinerator and run it for 25 years after which it goes back into Suffolk County Council ownership. The cost of building it – £180million – is coming out of SITA’s pockets.

SITA will be paid by the council to dispose of our household waste. Its profits will come from its industrial and commercial customers, electricity income and small amounts from heat energy, scrap metal and aggregates.

The incinerator, which has the capacity to deal with 269,000 tonnes of waste a year, will take household waste and some business waste.

“We produce something like 180,000 tonnes, after recycling, of black bin waste,” explains Cliff.

There is capacity to take the business waste, but for that, SITA faces competition from other contractors.

Unlike plans to build an incinerator at Kings Lynn in Norfolk, the Suffolk project has not faced major opposition, although at the start of the process, many years ago, there were some objections.

“The main controversy that there has been here has been about traffic implications,” says Cliff.

“Whether people in Suffolk are sensible or Suffolk County Council are good at consulting or SITA are good at communicating, we have ended up with a project that’s had less opposition than other projects.”

People are being pragmatic about it, he says.

“We are all creating that waste and somehow we have got to deal with it.”

SITA has put on public exhibitions both in the village, and county-wide. It regularly sends out newsletters to around 9,000 homes around the site, and holds community liaison meetings with representatives from the various parish councils, which have been ongoing for the past couple of years.

“There has been a lot of effort in trying to explain exactly what we are doing and why. In other areas, the opposition is based on total misconceptions,” he says.

Cliff has long experience in the energy industry, having started his career in coal, and believes that the safeguards to ensure plants such as his are properly run are iron-clad.

“In this industry we are heavily regulated by the Environment Agency. You must ensure the combustion completes so you take very great care in the design of these plants to ensure you hit the right temperature and you have the right amount of air to complete the combustion,” he says.

At the back end of the process, lime scrubbing takes place. In effect, the gas is sprayed with lime and urea and filtered to ensure that anything noxious is caught. Emissions monitoring equipment in the stack provides a continuous picture of the gases which come off.

Burning waste at high temperatures (900 degrees) helps to prevent emissions forming in the first place and the trace amounts that remain are thoroughly cleaned, using scrubbers and filters, he says.

The rigorous cleaning process means what comes out of the chimney is largely steam, oxygen, nitrogen and carbon dioxide with tiny amounts of pollutants, but these will be “well below” the strict levels set by the Environment Agency, he adds.

Monitors at the base of the chimney continuously check emission levels and if they start to rise, adjustments are made to the cleaning process. In the unlikely event they continue to rise, or if the monitoring equipment fails, the facility will automatically shut down.

Monitoring information from the chimney will be displayed in the visitors’ centre and on the SITA website. It also has to be sent to the Environment Agency, which carries out its own unannounced spot checks.

Switching to energy from waste will mean greenhouse gases will be reduced by an estimated 75,000 tonnes a year over the life of the contract, the equivalent to switching off Ipswich for two years.

In fact, says SITA, there will be more pollution from traffic on the A14 than there will be from the chimney on site.

The energy the plant produces will be connected into the National Grid 12 miles from the site at Stowmarket. There is also the potential to use surplus heat to help other businesses, and SITA is currently working with two farmers on a large tomato greenhouse scheme (see inset), which it is hoped will come to fruition at the same time as the plant becomes operational. Other businesses may also be able to benefit from the heat supply.

“We need to get the customers. It makes the whole thing even better environmentally,” says Cliff.

The estimated 70,000 to 80,000 tonnes which will come out as aggregate or bottom ash will go into road building.

The site will have a screening process that will separate the bottom ash into its different sizes. The bigger lumps will be taken away by wagon to be crushed off site.

Clive estimates the site will produce around 9,000 tonnes of ferrous scrap and non ferrous scrap a year which will go to SITA Metals. Of course, there is no guarantee on prices with commodities such as scrap metal but you have to take the rough with the smooth, he says.

There is a lime silt that is produced by the process called fly ash. Because it’s heavily limed or very alkaline metal, it’s very difficult to do anything with it at the moment, so that may end up as landfill, although SITA is in talks about making it into masonry blocks, which would give the plant about 100% avoidance of landfill.

“We are contracted to achieve about 94% avoidance of landfill and most of the 6% is about the fly ash and a little bit of bottom ash,” he says.

The furnace will be fired into action using oil, which will be used to get it up to temperatures of around 900 degrees.

In those kind of temperatures, anything that is flammable will rapidly dry up and burn.

It’s the industrial equivalent of using firelighters, and once fired up, the furnace will remain in action until it has to be shut down - generally for about two weeks a year for general maintenance.

“I visited one plant in Paris and they use a lot of waste wood. It’s anything that will burn readily,” he says.

“The good thing about oil is we can thereby guarantee that if we get any kind of problem with some part of the process we can maintain the temperature while we sort the problem out because it’s maintaining the temperature that is the big thing.”

The site will employ 43 staff, and these will need to be skilled, but the technologies and equipment used at the plant are known within the industry, and therefore there is a bank of knowledge about how to run them.

“It’s a power station. It’s the same technology as you have in a power station. Running power stations is known across British industry,” says Cliff.