With any new project there are always questions. Here are some answers to commonly asked questions. Please feel free to ask if you have other questions relating to the facility.
What is Anaerobic Digestion?
Anaerobic digestion (AD) is a series of natural biological process whereby biodegradable material, such as food waste, is broken down by micro-organisms in the absence of oxygen (anaerobic conditions). This process takes place in sealed vessels. As the food is digested by micro-organisms in these vessels odourless methane gas is produced and fed into an engine. The engine uses the gas as fuel and drives an electricity generator, which produces electricity.
As with any engine, the cooling system and exhaust get hot. Heat is a by-product of almost all energy generation methods. The heat generated by the facility here at Queen Charlton Quarry will be used to dry wet wood, making it into a useful fuel when burned in domestic and commercial biomass boilers.
Once the food waste digestate has stopped decomposing and producing gas, it becomes an odourless, sustainable fertiliser for farmers, full of valuable nutrient and trace elements, thus replacing the need for artificial fertilisers, which have a high carbon footprint.
What are the benefits locally?
1. Renewable Energy supply
The plant will produce 17,000 MWh of electricity per year. Ofgem gives UK household electricity consumption as 3.3 MWhr per year, which is therefore 5,151 households’ worth. Keynsham had 6,545 households in the 2001 census, so we will generate electricity for 79% of the households in Keynsham.
The plant will also produce a similar amount of heat per year. Ofgem gives UK heat consumption at 16.5 MWh per year, which means the site will produce enough heat to heat 1,030 households.
The AD facility has increased local employment from a staff of 5 to a staff of approximately 20.
3. Environmental enhancement
The site will be opened up to create a nature walk through the on-site woodland and will include natural ponds and a nature area. The woodland will be enlarged and the hedges improved and maintained, increasing biodiversity on the site.
The education centre to be built on site will provide a space for local schools, colleges and organisations to learn about the merits of waste as a resource and there will be opportunities for students to carry out projects, dissertations and work experience. We are already working closely with educational and conservation bodies to create a site of enormous ecological and environmental value both physically and educationally.
Shouldn’t we try to avoid generating any food waste at all rather than creating a need for it?
The ideal would be to avoid the generation of food waste completely but there will always be some waste from the food production industry or from catering leftovers, etc. AD uses waste which is not suitable for other waste re-capture options such as animal feed or redistribution due to health and safety restrictions or animal by-products regulations.
Is the gas dangerous?
There is no risk to the public from this facility. As always with industrial processes, those who work on the site will take the usual precautions.
Does the process cause pollution?
No, in fact the facility will reduce pollution by correctly processing organic waste and reducing greenhouse gases. All of the material being processed is held within sealed vessels.
The odourless digestate produced adheres to Animal By-Product Regulations (ABPR) as well as BSi Quality Assurance Standards. It is a valuable fertiliser with many benefits to agricultural land.
Why build in a Green Belt area?
Much of BaNES is within Green Belt. The facility demonstrates the very special circumstances that are necessary for a development within the Green Belt. The South West Regional Core Waste Strategy identifies the need for us to deal with our waste within our catchment areas. AD is an ideal way of dealing with food waste without reverting to landfill, as well as creating renewable energy and a sustainable fertiliser, all within our community.
Will there be an Environmental Impact?
The Secretary of State has confirmed that our AD facility is not a development which requires an Environmental Impact Assessment (EIA). It operates under an Environment Agency Standard Permit.
Will the facility affect wildlife?
No. Because of its long industrial history, wildlife has been confined to the field boundary hedgerows and woodland rather than the site. The facility will not affect the existing wildlife in any way. In fact the site will be ecologically improved through the extension of the existing woodland and improvement of the hedgerows as well as the installation of natural ponds, thus improving and increasing biodiversity on the site.
Will the site be noisy?
Noise levels will be below current day to day noise levels. Machinery will be in buildings, acoustic enclosures or deep into the site so that the sounds which reach the nearest house will be quieter than the noise levels that occur, day or night, already.
Does it smell?
No. All of the processes will take place inside sealed vessels. Vehicle deliveries will pass through an air lock into the Feedstock Building, which will be controlled so that only one of the doors may be open. The building will be kept under negative pressure which removes all odours. The Environment Agency will regulate and monitor all operations.
Will there be an increase in Traffic?
About 3 trucks an hour will enter and leave the site from the A37 via Charlton Road, which carries about 500 vehicles per hour. No lorries are allowed into Keynsham from Charlton Road because of the 7.5 tonne weight restriction at Redlynch Lane.
Once built, all roads and turning areas will be finished in tarmac or concrete so vehicles will not become muddy. Wheel washing will be provided for all vehicles.
Will it impact the area visually?
The visual impact of the proposal has been modelled and accepted by BaNES.
The facility will not be visible from anywhere to the south because the hill immediately behind. It will not be visible from any historic place, such as Queen Charlton Conservation Area, the Wansdyke mediaeval earthworks ancient monument or the World Heritage city of Bath.
Occasionally you might catch a glimpse: computer generated images of the facility are shown to scale in photographs from places where such views may be had, such as from houses on Bifield Road in Stockwood and Wellsway in Keynsham.
To help the facility blend into its surroundings, the colours and shapes of the design have been chosen to match the existing landscape. The existing trees and hedgerow which bound the site will be enhanced and additional trees will be planted on top of new mounding which will mostly hide the development.
During operational hours the facility will only require external lighting at dusk in winter in order to illuminate the loading apron for safety purposes. External lighting will adhere to the dark skies lighting principles. After hours, the site will remain dark unless disturbed.
Who is building the AD facility?
The developer of the project is a local team, comprising engineers, architects and operators with experience in AD and composting facilities.
What do local people feel about it?
A Residents’ Liaison Group was formed in 2011 to facilitate strong communication links with local residents and to allow them to keep abreast of developments on the site over the past few years. The past, present and future input from this group, and support from many local residents has, and continues to be, invaluable for the project.