One of Defra's new technology demonstration projects has been ordered to dispose of its residues, because they are not considered fit for restoring landfills, writes Emily Ross.

Premier Waste has been refused permission by the Environment Agency to use the output from its aerobic digester in Thornley, County Durham, for land restoration and it has been instructed to send 10,000 tonnes of the material to landfill.

Material is not being treated at a high enough temperature in the PARC system, the Agency has ruled

The Agency said yesterday that the material has too much glass and plastic in it, and has not been processed to a high enough temperature to be safe for spreading onto land.

The situation has arisen following local residents' complaints surrounding the odour coming from the Todhills landfill site, where the residues of the so-called PARC system had been stockpiled. The complaints were highlighted in a BBC documentary that aired last month.

Premier Waste, which is owned by Durham county council, had intended to use the material in restoring the landfill from this Spring. However, following an investigation, the Agency revealed last night that the material is unsuitable for this purpose.

A spokesman from the Environment Agency explained: "As a result of our investigations of the 'compost-like output' (CLO) deposited at the Todhills landfill site, the Environment Agency has concluded that this CLO was not suitable for site restoration. The registration of Premier Waste as a company that can spread CLO at Todhills has been refused.

"The Environment Agency has therefore today (Wednesday 19th March) instructed Premier Waste Management to dispose of all of the CLO deposited at Todhills at a suitably permitted landfill site," the Agency spokesman confirmed.

Demonstrator

The Premier Advanced Recycling Centre (PARC) system began its commissioning in May 2007. It uses aerobic digestion to process up to 20,000 tonnes of municipal solid waste per year through a vertical invessel composting tower.

It works through the biological digestion of the biodegradable components of mixed residual waste, which turns the material into a light fibrous material. Once the waste is digested, the metals, plastic bag fabric, glass and compost are segregated. The metal, plastic bag fabric and glass is sold on for recycling.

Defra, which has part-funded the plant through its New Technologies Demonstrator Programme, has said of the system that: "The Parc system allows the capture of around 40% of the carbon in waste, thus massively reducing emissions and the carbon footprint of any Local Authority."

Commenting on the Agency's order to landfill its residues, Premier Waste chief executive Les Grant said: "Information received today, March 19, from the Environment Agency indicates that such material must now be landfilled. In addition the Environment Agency has drawn our attention a need to reduce the amount of plastics and glass in the CLO.

"We have immediately taken steps to comply with this request and 10,000 tonnes of affected CLO will be removed from Todd Hills and Joint Stocks and moved to the landfill at the Joint Stocks facility," Mr Grant added.

Re-engineered

Despite the problems, Mr Grant insisted that the company remains commited to the technology, and he said that he believes that the problems "can be quickly and effectively eliminated."

He went on to explain how the Thornley digester will be re-engineered. This will involve the following steps:

• Installation of a new temperature monitoring system
• Installation of a substantial heater phase in the bottom compartment of each tower, which will ensure absolute achievement of Animal Products temperature requirements.
• The application of insulation to the outer skin of the metal towers to improve heat retention.
• The installation of a new trommel screen to improve the CLO segregation stage and reduce physical contaminants. This equipment "is actually being delivered today", the company noted.

Mr Grant said: "We are very confident that these various measures can address the difficulties that the plant has experienced over recent months.

"We will be working closely with Defra Animal Health and the Environment Agency throughout this period to ensure that they are content with the results of the programme and that we have a clearly agreed basis for future commercial operations of the
plant.

"Once the plant is back on-line it will be producing outputs to a standard which is acceptable to our regulators and our clients, and which addresses any public concerns about the technology," Mr Grant said.