Waste technologies submission by GAIN

(Guildford Anti-Incinerator Network)


for consideration by the



5 April 2006


GAIN welcomes the opportunity to contribute to the Committee’s deliberations and notes the terms of reference: -


‘the Committee will only consider evidence or cited evidence as part of the reviews of waste treatment technologies and Surrey’s waste management strategy. People may submit opinions and views as part of the formal consultation around the joint strategy in the summer’




Matching Technology to Separated Waste Streams


Municipal Waste is a challenging feedstock for a treatment plant because it is variable and mixed. Professor Jim Swithenbank, Sheffield University Waste Incineration Centre

The waste industry is remarkable for its ignorance about the composition of the material it is treating.  Brian Jones, Biffa

Waste treatment processes can be made more reliable and the emissions and outputs can be more readily controlled if waste is sorted according to its properties so that any particular stream is more homogenous.  The cocktail effect is also reduced.  Overall, the range of technologies available for treating municipal waste increases if different materials are separated out and some well-established technologies used in other areas, such as in sewage treatment, become available.


There are therefore advantages in identifying which technology might be most appropriate for each type of waste material and in being familiar with overall waste composition.  There are also advantages in determining whether some materials should be phased out of the waste stream over time rather than catered for at currently predicted rates.


Technology Suited to Surrey


Surrey has high levels of NO2 and NOX with high traffic levels, major congested roads including the M25, M3 and A3 and the effects of two major international airports.  It also contains the Thames Basin Heathlands, designated under the European Habitats Directive, which are vulnerable to such pollution.

There would be advantages in avoiding thermal waste treatment processes that make a significant contribution to nitrous oxide emissions.


Surrey has a high population density combined with a large proportion of land – both in the countryside and in settlements – that is designated for its landscape value.  There is therefore a great interest in establishing waste treatment processes that make acceptable neighbours and minimise adverse landscape impacts.  These become important factors in technology assessment.


Hazardous Household Waste


Whatever waste technology is pursued, there would be advantages in removing toxic materials such as batteries, paints, chemicals, medicines and asbestos from the mix.  Such products would cause problems for the quality of waste treatment outputs from thermal or biological processes.  It will therefore be important to ensure that technology is provided for handling hazardous household waste materials and where possible recycling or treating them.  Such facilities are likely to be more suited to a regional scale of operation as envisaged in the draft Regional Waste Strategy.  However, Surrey’s contribution to such infrastructure should not be overlooked in the mix of facilities to be provided.


“Energy from Gas”


Use of the term “energy from waste” for “incineration with energy recovery” could distract attention from the energy generating potential of other waste processes and might usefully be reviewed.  As described in the Draft Regional Waste Strategy, if biodegradable waste is treated in an anaerobic digestion plant, 60% of the output is biogas, which can be cleaned and harnessed for energy.  This is particularly significant when considered alongside the fact that about 80% of Surrey’s municipal waste is biodegradable.  Gas can be harnessed from in-vessel composting or even from undesirable mixed landfill.  The potential of energy from various waste processes is less likely to be overlooked if “…with energy generation” is added to any relevant process be it incineration, anaerobic digestion, in-vessel composting or mechanical and biological treatment.  The potential to produce energy from the biological fraction of residual waste could be valuable in generating energy for cleaning the non-biodegradable fraction in an adjoining plant.        


Treatment of Residual (not Recycled or Composted)


An analysis of the composition of Surrey’s waste remaining, once maximum recycling and composting have been achieved, would be valuable.  It is difficult to undertake an analysis of the most appropriate technology for this residual waste without a better understanding of the materials to be treated.  Working from first principles:

-         the biodegradable residual will be well-suited to biological treatment in a controlled environment,

-         some of the non–biodegradable residual will lend itself to being cleaned and

-         some residual will be best-targeted for being avoided or substituted with materials that are more readily reused, recycled or composted.



Waste Treatment Residues


Surrey’s draft Waste Disposal Plan assumes incinerator ash would have toxicity levels that would enable it to be recycled.  In practice, over 60% of bottom ash is not recycled, (Parliamentary Question by Ann Milton MP) and unacceptable dioxin levels have been recorded in ash that has been used as hard core (at Byker).


By comparison, Surrey’s draft Waste Disposal Plan assumes biological treatment residues will have to be landfilled.  This overlooks the significance of separating out biodegradable wastes into food, garden and less clean.  Much of the output would be a clean and useful compost product if the waste streams were treated separately in this way.  Biological process units tend to be modular and well-suited to segregation of throughput.  Any lower grade compost from a small proportion of less clean biodegradable input would be sufficiently treated that it did not attract high biodegradable landfill tax penalties.


“Clean” Landfill


In considering technology options, it is important not to overlook the potential for clean landfill taking separated, treated or stable material that is not biodegradable.  This could be an environmentally acceptable disposal option for a small and diminishing amount of the non-recyclable, non-biodegradable waste or for the solid output from some biological treatment of less clean biodegradable waste.      






It would be easy to jump straight into the merits, or otherwise, of the ‘big’ and ‘expensive’ technologies. But since we are invited to consider the environmental, health and economic aspects of waste treatment options perhaps we could look at the ‘low tech’ option of home composting in this light.






Provided that people are willing and able to compost, (difficulties for flat dwellers are acknowledged), this methodology ticks all the right boxes: -


Home composting keeps biodegradables out of the waste stream and produces material that will enrich garden or allotment, so it is very environmentally sound. The producer saves money by not having to buy compost and has a vested interest in keeping council tax low.


Collection authorities have started to collect ‘green waste’ to provide a service for residents and to stop it ending up in landfill; home composting prevents this material from ever entering the ‘formal’ waste stream.


Food waste collections will be costly compared to the cost of a ‘green cone’ or similar composter. Defra and WRAP are currently carrying out trials of difference systems. On 5th January 2006 the letsrecycle website reported a study by Dr Alan Knipe [1] showing the potential substantial diversion of food waste and cost savings if households used food digesters. 


WRAP, working with 56 partners in England, aims to sell 500,000 green waste composters in 2006. (


Home composting is the cheapest version of waste management, there are none of the environmental or cash costs associated with collection or transport – we can all become waste managers!


In various countries in the EU there are large government programmes to promote home composting; Flanders in Belgium is cited in an EU document. [2]




The Landfill Directive has given impetus to the introduction of more sophisticated biological treatments in the UK. These are common in Europe. As part of the development of the Thematic Strategy on the Prevention and Recycling of Waste (TSPRW) for Europe a study of biological waste treatment was carried out in the countries of Germany, Italy and the Netherlands. 2    


Biological treatments can be stand alone processes relying on source separated material such as green waste or food waste, or they can be used to treat mixed waste which has undergone mechanical pre-treatment.


Organic waste can be treated aerobically, in the presence of air, for instance, in windrow composting, or in closed systems such as containers, tunnels or housings.


Anaerobic digestion processes take place in closed vessels in the absence of air.




Composting is a flexible waste management treatment. The study of the process in three European countries showed many applications of different sizes and technological complexity. All three countries regarded biological treatment as a tool to reduce landfill reliance.  The study showed that 80% of the German municipalities had decided to establish separate biowaste collections, in Italy it was estimated that 3000 municipalities were running source separation for food waste and in the Netherlands 92% of the population were involved in the separate collection of organic waste as far back as 2002. In Italy the need for organic matter to support horticulture and fruit growing in the south of the country is regarded as a marketing opportunity.  All three countries have established quality standards for compost.


With the anticipated significant increase in composting in the next 5 to 10 years, WRAP has commissioned Enviros to produce draft guidelines on the use of compost, from source-segregated organic municipal wastes, in agriculture and field horticulture. 


In the UK there are many new initiatives to promote centralized composting schemes, on 13th March the letsrecycle website carried news of Minister, Ben Bradshaw, at the opening of a composting facility in North London operated by Agrivert Ltd on behalf of LondonWaste Ltd and the North London Waste Authority, other stories featured Wigan, Swindon, the Wirral (using Merseyside’s in-vessel composting plant at Bidston), Sunderland and Slough.


WRAP has welcomed the news that Agrivert has become the 60th compost producer to join the Composting Association’s quality certification scheme, BSI PAS 100.


Biological treatment producing biogas will be at the heart of Scotland’s Western Isles Council’s new waste management facilities. (Earth Tech Engineering Ltd)


Windrow composting


In the past the windrow method has been the main method of composting green waste. This is a well established, relatively simple process. Any site used must be properly prepared with a hard surface to prevent soil contamination. Well controlled regular aeration, generally carried out by mechanical turning of the heaps, is required to prevent odour and to encourage the swift breakdown of the material. Primary emissions to air are water vapour and CO2, although CO2 is a greenhouse gas it is less potent than the methane that would be released from potential landfilling. Wastewater is dispersed via a sewer. If not well managed windrow sites can be bad neighbours and should not therefore be sited in the vicinity of dwellings. As well as possible odour problems, noise caused by lorry movements and the machinery used on site can be a problem, as can significant traffic movements in narrow country lanes. Windrow, on a small scale, can offer farmers a means of financial diversification and sites can sometimes be appropriately sized to serve a local need, thus avoiding transport costs and lorry movements.   


In-vessel composting


In-vessel composting takes place in an enclosed vessel or tunnel and gives more precise temperature control. Higher temperatures, sufficient to destroy potentially harmful bacteria can enable the requirements of the Animal By-products regulations to be met.  Green and kitchen waste can be treated together. Costs are higher than for windrow composting but since most systems are modular they can be sized according to a local need, thus avoiding transport costs and movements.


Examples of in-vessel composting in the UK include the Wyvern Waste plant at Dimmer, which is run on behalf of Somerset County Council. This plant had to gain the approval of both the Environment Agency and the State Veterinary Service before it could deal with garden and kitchen waste.


In July last year WRAP awarded Jack Moody Ltd funding towards building an in-vessel composting plant at Hollybush Farm, Shareshill, near Wolverhampton. This will enable the company to process a planned 40,000 tonnes of kitchen waste in addition to continuing to windrow compost green waste.


Biffa have outlined plans for an in-vessel composting plant capable of dealing with organic waste covered by the Animal by-Product Regulations at their Poplars landfill and recycling facility near Cannock.


Agrivert are providing in-vessel composting facilities at the LondonWaste EcoPark in Edmonton, with a 30,000 t/pa plant composting green waste and kitchen waste. Agrivert’s website carries the following quote from Dr Stephen Wise-Merry, Head Organics at SITA: - “In-Vessel Composting is one of the most potent weapons available in the fight to reduce the amount of biodegradable waste sent to landfill.”


Liverpool is investing in a £3 million pound in-vessel composter capable of dealing with up to 20,000 tonnes of green and food waste. The technology is based on a New Zealand system from VCU Europa.



Anaerobic digestion


Anaerobic digestion is used to treat wastes with a high organic content in closed vessels in the absence of air (oxygen). The biochemical process results in the formation of a carbon dioxide and methane mixture, ‘biogas’. The proportions of carbon dioxide and methane in the mixture are determined by the waste stream and the temperature of the system. The other output is a semi-solid residue (digestate). Biogas can be used as a natural gas substitute but is generally used to generate electricity to run the plant. In the UK the sale of any surplus electrical power is eligible for the Renewables Obligation Certificate scheme.


As anaerobic digestion only decomposes biodegradable material it is most often used in Europe in conjunction with the mechanical pre-sorting of waste, (MBT).


The main environmental driver towards anaerobic digestion in Europe has been the Landfill Directive. Each of the three European countries studied in the TSPRW 2 has stringent landfill regulation. In Germany the land filling of organic waste was prohibited from June 2005, in Italy there is a ban on the land filling of untreated MSW and in the Netherlands there is a ban on the land filling of combustible waste (except in the case of inadequate incineration capacity), biowaste and untreated MSW.



Environmental Factors: -



For a comprehensive review of all the environmental aspects of Anaerobic digestion read the Friends of the Earth briefing document ‘Anaerobic digestion’ published in November 2004.


Financial factors and markets: - 





There is a full scale anaerobic digestion plant in the UK is run by Biffa at Wanlip in Leicester. As well as processing the biological fraction of MSW from the Leicester area, after ball mill processing, it accepts source separated kitchen and garden waste. There are 5 digester tanks with a total capacity at any one time of 8,000 tonnes.


A small digester, 5,000 tonnes/year operated by Greenfinch is scheduled to open at Ludlow in Shropshire in Spring 2006. This will take source separated kitchen and garden waste collected from local residents and will provide electricity and heat. The heat will be exported to the neighbouring industrial estate. Local farms will receive a pasteurised biofertiliser.


As mentioned earlier, an anaerobic digester is being provided in the Western Isles of Scotland. The project, which is sited near Stornaway on the Isle of Lewis, is led by Earth Tech with anaerobic digestion technology provided by Linde and in-vessel composting equipment from HotRot.




There are currently 18 plants in the UK incinerating Municipal Solid Waste. [4] 9% of MSW is incinerated.


Most of the incinerators currently operated in the UK are ‘moving grate’ plants. These are designed to deal with household waste with no pre-treatment. A continuous stream of waste enters at one end and is propelled through the furnace by a mechanically moving grate with ash being discharged at the other end. Constant close management is required to ensure that the optimum levels of combustion are maintained. 


Environmental and health factors




‘Throughout our review we have stressed the need to clarify the uncertainties inherent in the data in this report and consider the implications this uncertainty has when evaluating the environmental and health effects of waste management. Although the uncertainties have been acknowledged in this report, it is important that anyone using these data takes adequate consideration of its inherent uncertainty.’
















‘Incinerator emissions are a major source of fine particulates, of toxic metals and of more than 200 organic chemicals, including known carcinogens, mutagens, and hormone disrupters’













Economic Factors









We note that the CIWM states that ‘Pyrolysis/gasification remain unproven’ (National Waste Strategy for England 2005 Review – DEFRA/CIWM Regional Workshops to Support Phase 1 of the Strategy Review: ‘Resource Efficiency and Sustainable Waste Management’ – July 2005)




At a recent meeting, the Leader of the Council, Nick Skellett, reminded the Executive that current, and on-going problems with landfill should not be forgotten. GAIN shares his concerns and hopes that your Committee will work with the portfolio holder and the contractor to address these issues as a matter of urgency. 







There has been widespread dismay that Surrey County Council is advocating two incinerators in its recent Waste Disposal Strategy (part of the Joint Municipal Waste Strategy).  This must not be allowed to overshadow the fact that their strategy also includes a great breakthrough in waste thinking.  Surrey now proposes that different types of waste should be collected separately, including biodegradable food waste.  If the full consequences of this are followed through, Surrey will not need incineration as part of its strategy.  The possibility of working with the community on the efficient delivery of an incinerator-free strategy that enjoys significant support and meets targets is within reach.


If, as proposed, the waste materials are separated, it becomes possible to match the waste treatment plant to the material.  This greatly reduces the adverse pollution impacts and also means that simple, proven, affordable waste treatment processes can be used.   By contrast, dealing with mixed waste presents problems for the effectiveness of all waste treatment processes and exacerbates pollution risks.




The level of ignorance about the composition of waste nationally is shocking and is symptomatic of how little effort has been put into cleaning up waste processing.  When it comes to commercial and industrial waste, there are not even good data on the quantities produced.  Surrey has made an excellent start at analysing its waste composition.  It must now use that knowledge to identify the best processes for dealing with the different parts of its waste stream.       


Surrey has discovered that over 60% of our waste is biodegradable and, of that, a lot is food waste.  It is this biodegradable fraction that can no longer be sent to landfill.  Whenever possible, the paper or wood should be recycled.  The rest will be far better suited to some form of biological treatment than to burning.  It makes little sense to waste energy trying to burn a sloppy waste porridge in an incinerator, producing toxic combustion by-products.  Biological treatment offers great flexibility because it works well in smaller units that it would be relatively easy to accommodate in Surrey as long as all parts of the process are sealed.



IN-VESSEL COMPOSTING CAPTURING GAS: facility 1 (scattered distribution)


The first call on funds for new plant under Surrey’s SITA contract should be to establish several in-vessel compost plants with gas captured for energy.  As they will be processing a sorted waste stream, they will produce usable compost and it will be practical to clean the gases resulting from the accelerated in-vessel decomposition to produce energy and heat.  It would be possible to treat garden waste and food waste in different streams at a plant.  This would make it easier to decompose food waste at high temperatures and to keep food-derived compost separate if avoidance of its use on certain types of agricultural land were ever required.  To date, two to three in-vessel compost plants, for food waste only, are being suggested by Surrey, supported by SITA.  Possible sites being proposed are in Guildford, Leatherhead, Shepperton, Longcross and Redhill.




The second call on PFI funds should be a “continuous” anaerobic digestion plant.  This is a biological process that decomposes biodegradable waste in the absence of oxygen.  It fared well in assessments and is encouraged in the draft Regional Guidance.  It has a track record from its use in sewage treatment.  If biodegradable waste is treated anaerobically (without oxygen), 60% of the output is biogas that can be used for energy.  If there is screening at the front of this process and treatment of the output (such as cleaning and stabilizing using energy generated by the plant), this approach becomes known as a type of “non thermal mechanical and biological treatment”.  The quality of the solid output would depend on the mix of materials into the plant.  Cleaner input would produce usable compost and soil conditioner.  More mixed streams would produce stable compost that would be sufficiently decomposed and reduced in volume that it could be landfilled without attracting high Landfill Allowance Trading Scheme penalties.  Communities where incineration is currently planned might not object to a small and appropriate anaerobic facility for a sensible part of Surrey’s waste, subject to all the right conditions being met.        




In order to determine whether there should be an additional larger facility and what type of plant is required, Surrey needs to do further work on its waste stream.  We know 80% of Surrey’s waste is recyclable and compostable.  The question Surrey CC now needs to answer is this: What will be the composition of the remaining waste after maximum reuse, recycling, composting and other biological treatment?


If much of the material is non-combustible, trying to burn it would be unwise.  It is important to realize that if you recycle plastic, paper and wood and compost organic matter, then most of the calorific material an incinerator relies on has been removed.  It becomes hard to keep the fire burning consistently and temperatures drop to levels at which highly toxic, partial combustion compounds are produced such as dioxins and furans.  You end up needing to pump gas into an incinerator to try to maintain temperatures high enough to keep emissions below limits.  This is expensive and breaches occur.  Also, if much of the input to an incinerator is non-combustible, a lot of bottom ash is produced requiring landfill.


Working from first principles, in advance of the missing work on waste composition, it is likely that some form of “mechanical and biological treatment” would be a candidate technology for the second of the larger facilities in Surrey.  This could, as one of the components, include an autoclave facility for cleaning waste.  These require energy, which could potentially be generated by a compost or anaerobic digestion plant on the same site.  The objective for any residues from the plant that could not be used would be to produce a greatly reduced, stable material for clean landfill.  If these outcomes can be achieved without incineration, why employ this deeply unpopular technology with all its associated pollution risks?  Remember, incinerators need to landfill ash.








A summary of unaddressed concerns with incineration is appended.  The Environment Agency reported to Parliament that between 1996 and 2001, there were 899 unauthorized breaches of emission levels from the 10 to 12 incinerators in England and Wales.  The state of the art Lewisham incinerator breached safety limits 111 times during these four years.  The Dundee incinerator had an accidental fire in its first year.  During certain weather

conditions, called temperature inversions, instead of dispersing, incinerator emissions are trapped at ground level and build up to intolerable levels.  Highly toxic fly ash from the Newcastle incinerator was used as hardcore throughout the community over many years.  As confirmed in a recent Parliamentary Question by Anne Milton, over 60% of the bottom ash from incinerators goes to landfill.   There have now been over 85,000 objections to incineration in Surrey.     




No waste processing is impact free.  We call on Surrey to present a proper assessment of a non-thermal strategy for Surrey’s waste so that this option can be fully assessed in the public consultation on the Joint Municipal Strategy.  Given the public and local authority interest in pursuing an incinerator-free option, and that such options fared well in appraisals and consultations, we find it unacceptable that Surrey is only offering a worked-up strategy based on incineration.


We are pleased that certain County Councillors share this concern and are anxious that Surrey is muddling its various waste roles in its zeal to promote incineration.  We are troubled that, when incineration did not come out well in Surrey’s assessment of the Best Practicable Environmental Option, the weighting given to “practicality” was doubled, to elevate incineration to the top ranking.  Problems with incineration are being ignored and problems with other approaches played up in biased reporting.  We need objective analysis to make informed, science-based decisions




The SITA contract is being renegotiated.  Under the terms of the contract, it would be relatively straightforward to substitute, for two incinerators,

-                several in-vessel compost plants with gas capture,

-                an anaerobic digestion plant

-                and a mechanical and biological treatment plant.

The PFI money has hardly been touched because so little progress has been made on delivering waste services (about £3.77 million of £100 million by 2005).  Surrey has agreed a financial mechanism with SITA for providing In-vessel compost plants.


The Waste Contract needs to deliver Surrey’s Waste Strategy and not drive it.  We need reassurance that Surrey is not in the process of renegotiating the contract to deliver two incinerators and only changing the location of the Redhill incinerator to Longcross.  The negotiation is taking place in advance of a Joint Municipal Waste Strategy being agreed.  The old Waste Contract became the de facto Waste Plan.  We should not allow that to happen again.                                                                                                                   




2        Unaddressed problems with incineration

3        Information sources






Appendix 2





          Even modern incinerators have a poor record on emissions


          Studies only look at ideal operating conditions at odds with reality


          NO2 and NOX emissions tip Surrey above limits


          Hazardous landfill site needed in Surrey for toxic ash produced as result of burning process itself


          Waste drawn in from London


          Human body vulnerable to inhaled toxins


          85,000 objections to incineration in Surrey


          Not well suited to Surrey’s waste


          Waste of resources




Appendix 3



Some Useful Sources of Information on Waste


The GAIN website at


CIWM (Chartered Institution of Wastes Management) website -


SLR Consulting Ltd for CIWM ‘Delivering Key Waste Management Infrastructure: Lessons Learned from Europe’ Nov 2005 -


BBC website -


Letsrecycle website -


Defra website – WRAP etc -


Defra – WIP – ‘Options for the Diversion of Biodegradable Municipal Waste from Landfill’ -


Environment Agency website -


Health Protection Agency website -


FOE (Friends of the Earth) website -


Greenpeace website -


GAIA website -




END’s (Environmental Data Services) -


NSCA (National Society for Clean Air and Environmental Protection)  -


SEERA (South East England Regional Assembly) -


Community Recycling Network -


ICE (Institution of Civil Engineers) website -


Europa, an EU website -


Renewable Energy Association website -


SITA website -


BIFFA website -






[1] The Management of Household Food Waste – Dr A D Knipe - 29 November 2005

[2] Support in the Drafting of an ExIA on the Thematic Strategy on the Prevention and Recycling of Waste (TSPRW)

[3] ‘Introductory Guide’, ‘Options for the Diversion of Biodegradable Municipal Waste from Landfill’ - July 2005

[4] SLR Consulting for CIWM– Delivering Key Waste Management Infrastructure: Lessons Learned from Europe November 2005

[5] FOE Media Briefing – Up in Smoke - January 2006

[6] Final report to the European Commission, DG Environment, July 2001 by AEA Technology