A1 The Welsh Government is driving a programme to encourage all local authorities to recycle food (organic) waste into electricity and fertiliser.  This is all part of a UK wide plan to reduce the amount of waste we send to landfill, as this is detrimental to the environment.  To encourage recycling, the Government is increasing landfill taxes year on year so local authorities are forced to seek more environmentally responsible alternatives for disposing of waste. The Welsh Government is leading the way with their policies regarding the treatment of organic waste.

Anaerobic Digestion - AD - is considered to be a win: win process; not only is it a clean, efficient and cost effective method of treating organic waste, it also provides a valuable source of power from the biogas produced and the residual sludge, known in the industry as digestate, can be used as a valuable fertiliser for the land.

Denbighshire, Conwy and Flintshire local authorities have joined together to form what is known as the North East Wales Hub, which has overseen the procurement process for a technology provider to build and manage the operation over a long-term contract.

TEG Environmental, working in partnership with a specialist energy company, Alkane Energy, has been selected as the Preferred Bidder.

A2 Anaerobic digestion - or AD as it is often known - is a process whereby microorganisms break down biodegradable material in the absence of oxygen. The process produces biogas which can be harnessed to produce power.

A3 The AD process is likened to the digestion process of a cow's stomach, in that microorganisms break down organic matter, which in turn produces gases.  These gases can be harnessed and piped into a generator to produce renewable energy in the form of heat and electricity.  The other residues, rather like cow manure, can be used as a valuable fertiliser for the land.  The process takes between 50 and 70 days.

A4 The plant will be built on the site of a former abattoir at Holywell Road, Waen.  This site is just off junction 28 of the main A55 expressway, so ideally placed for access whilst causing minimum traffic disruption to the local neighbourhood.

A5 No, TEG is only using part of the site and is paying a lease for using that part of the land, which remains under local authority ownership.  At the end of the contract term the whole facility will be owned by the NE Wales hub.

A6 Organic waste, mainly kitchen waste collected from households in Denbighshire, Flintshire and Conwy by their local authorities.

A7 The plant has the capacity to process 20,000 tonnes of waste per year.  At least 11,000 tonnes will come from the three local authorities, with the remainder coming from other local authorities and businesses that generate food waste.

A8 TEG's proposal, which is subject to planning permission, is to use about a third of the site.  Denbighshire Council has stated its intention to develop the site to the satisfaction of the local community as well as to realise any potential revenue that can be generated. 

A9 Detailed drawings will be submitted as part of the planning process, but the plant will be designed to be in-keeping with the rural setting and will have the appearance of farm/agricultural buildings.

A10 November/December 2011

A11 Environmental Permit for a waste operation

Animal By-Products Approval

PAS110 Accreditation

A12 Waste processing is expected to commence in Spring 2013, with full operation being achieved in the autumn of the same year

A13 The AD process breaks down organic matter in the absence of oxygen, therefore it needs to be completely sealed.  Microorganisms break down the waste as it is stirred and warmed in the large sealed tanks into which it is loaded.

The main constituents of the biogas produced are odourless (Methane and Carbon Dioxide) however there will be small quantities of other gases present in the biogas that are odourus. 

The biogas will be fully contained and also cleaned and dried before being converted into power. The generation of power is a significant income stream for the operator, so there is every need to ensure no gases escape. The gas pressure inside the sealed system is monitored at all times.

Waste arriving on site will be unloaded within the building and the waste reception area operates under negative pressure, which means that when the door is opened to allow a vehicle to enter or exit, air from outside is sucked in to prevent any odorous air from escaping. All the air from the waste reception building will be treated prior to being released.

The site will be regulated and monitored by the Environment Agency and if any permits are infringed, then the operator's licence can be suspended or revoked.

A14 The AD system comprises of large vessels, which contain the waste whilst it is digested. The temperature is kept at around 40 degrees for optimum performance and it is gently stirred to aid the process, which takes between 50 and 70 days. The process is therefore virtually silent.  The biogas is drawn off through pipes to use as fuel for small electrical generators and these are extremely quiet machines.  They cannot be heard from a distance of 3 metres.

Vehicles using the plant will be no noisier than any other road vehicles and when they discharge waste, this will be done inside the building so again, noise will be minimal. All equipment on site will be selected and designed to minimise noise emissions.

A15 It is envisaged that an average of 15 vehicles a day will use the site. Most of them will be 7.5 tonne vehicles.

A16 As part of the trading contract we will ensure that vehicles are instructed not to use the back roads as a short cut.  However, there will be some vehicles using those roads, as they have to access local households to make collections.

A17 The facility will be open from 08.00 to 17.00, Monday to Friday and potentially on Saturdays from 08.00 to 12.00.  

A18 Although the AD process is continuous, it is fully automated and does not need operatives to monitor progress continually.  However, sophisticated monitoring and warning systems will be installed to alert if there are any systems failures.  In the event of such an occurrence, call-out rotas and procedures will be implemented.

A19 The site will be operated by TEG and Alkane. As both companies are listed on AIM (Alternative Investment Market) it is requirement that they create a separate operating company for such business collaborations.  When financial close has been reached with the NE Wales Hub, a separate company, to be known as Neat Biogas, will be created.  The site will be known as the NEAT Biogas site, but all personnel involved in the project development will be contracted via TEG Environmental and Alkane Energy.

A20 A Site manager and two operatives.

A21 Local construction staff will be used wherever possible. On-site staff will carry out routine maintenance but more detailed maintenance works will require specialist skills.  If local people had those skills, then they would certainly be considered.

A22 Gas engines.

A23 The biogas produced will provide up to 1MW of energy, sufficient to power the plant with enough excess electricity to power up to 2,000 homes.  The excess electricity will be sold to the national grid.

We envisage the plant will produce around £20,000 tonnes of liquid fertiliser. Any remaining waste will be transported to TEG's composting plant in Todmorden, where it will be put through our natural composting process.

A24 Yes, we can. We have pledged to create up to 6 months storage - some enclosed on site - and will identify off-site enclosed storage.  

A25 Unfortunately currently this is neither a practicable or economic option.  The Waen site currently does not have a gas connection, so it would be unable to export gas. The  anticipated methane content of the biogas produced at Waen is <60%. To export gas into the National Grid the methane content has to be above 98%. The cost of 'cleaning' the gas to this quality is currently prohibitive.

A26 A new import /export connection will be ordered ?from Manweb which will be housed in a new substation building, similar in size to the existing  substation on site.

A27 The process has a high temperature flare that is called into operation to maintain the pressure of the biogas in the AD plant systems and thereby allow the anaerobic digester to continue to operate safely and without interruption.  This flare is used to burn off excess gas during breakdown and routine maintenance to ensure that there is not any build up of gas in the system.

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