4 Residual waste treatment |
waste for energy recovery
56. Importing and exporting waste for recovery is
generally permitted, depending on country controls, waste type
and destination. Refuse derived fuel (RDF) is low grade fuel processed
specifically for consumption in energy-from-waste facilities.
There has been a marked increase in exports of RDF from England
to Europe since 2010 (when there was virtually nil).
In 2013, England and Wales exported a total volume of 1,157,895
tonnes of RDF, primarily to the Netherlands (69.6%) and Germany
57. This relatively new practice seems to have sprung
up in reaction to a lack of available energy-from-waste infrastructure
in England. David Palmer-Jones, CEO of SITA UK, explained that
the export of RDF is:
probably more of a temporary market, and it is
because we are diverting more away from landfill without the infrastructure
there is absolutely a position for that over a
period of time, as we make this adjustment in terms of infrastructure
58. CIWM share this view about availability of infrastructure
capacity and explain that:
the rapid development of the energy-from-waste
export market from England suggests that inadequate energy recovery
Long term reliance on exports of waste for
energy recovery open up the risks of that capacity not being available
to English markets-possibly at short notice-and denies the use
of waste derived fuels in England as part of a diverse and secure
energy supply mix.
59. Many witnesses called for more infrastructure
capacity to treat waste in England. Different technologies are
needed to treat different types of waste, but all share the common
trait of needing a significant amount of investment and relatively
long lead-in times. The National Association of Waste Disposal
Officers warned that "without an overview of the number and
location of the various processing options, the risk of creating
over-capacity in some methodologies, which would in turn threaten
the viability of others, will be a risk".
Dr Liz Goodwin at WRAP looked to Defra to play a role in ensuring
that the right amount of the right type infrastructure is available:
Defra has a role to play in understanding the
waste flows and the materials flows in the economy, and thinking
about what makes sense to be exported, what should be reprocessed
in the UK and how we help ensure that infrastructure is present
in the UK.
60. We recommend that Defra analyses data on waste
flows and waste flow forecasts in order to provide the waste sector
with clear guidance on how much energy-from-waste infrastructure
capacity is needed in England to gain an optimal balance between
export and local treatment.
61. Some witnesses were also concerned that the practice
of exporting RDF does not adhere to the principles of the waste
hierarchy and can have adverse impacts on the economy due to the
loss of resources and loss of potential investment in infrastructure,
employment and associated community benefits in England.
The export of RDF also impacts on energy security and Defra acknowledges
additional concerns around minimally treated RDF which contains
significant quantities of recyclable materials being produced
62. In response to the various concerns surrounding
the practice of exporting RDF, Defra issued a call for evidence
in March 2014 to determine whether there is a case for Government
action to ensure that export of RDF is the best treatment option
in terms of the environment. Defra is still analysing the feedback.
63. We commend Defra for issuing a call for evidence
on the practice of exporting RDF and we look forward to Defra's
response in due course.
64. We recommend that, in its response to this
Report, Defra include an assessment of the economic impact of
building the infrastructure needed to treat the RDF currently
exported compared with the economic impact of the current practice
of exporting RDF from England to other countries in Europe.
65. In the anaerobic digestion (AD) process, food
waste and other wet biowaste (e.g. manures, slurries and sludges)
is broken down by micro-organisms in enclosed containers in the
near absence of oxygen. Defra has scientific evidence, based on
life-cycle analysis, which shows that anaerobic digestion is environmentally
better than composting and other recovery options for food.
This is an example of an acceptable departure from the waste hierarchy
where a clearly better environmental outcome can be shown.
66. Defra worked with industry to develop the Anaerobic
Digestion Strategy and Action Plan 2011, with an aim of overcoming
the barriers to the deployment of AD. There are currently 145
operational AD plants in the UK with an installed electrical capacity
over 150MW. Of these 145 plants, 44% treat agricultural waste
such as farm manures and slurries, 38% treat food waste from municipal
and commercial sources, while the remaining 18% process industrial
waste such as brewery effluent.
The Anaerobic Digestion and Biogas Association notes that there
is still significant potential for the AD industry to expand as
only 7% of all waste is currently processed through AD.
67. Evidence we received predominantly praised the
effectiveness of Defra's Anaerobic Digestion Strategy and Action
Plan 2011 and welcomed the clear central Government commitment
it demonstrated, although some witnesses pointed to DECC's renewable
energy incentives as much more of a driver towards building new
68. Despite its growing deployment, AD operators
still face a number of challenges, including access to regular
and appropriate waste feedstock over the life of the AD plant.
Some witnesses, including Dr Goodwin at WRAP, endorsed separate
food waste collections, to get the food out of landfill and to
use it to generate energy and biogas through the anaerobic digestion
about four million tonnes of food waste still gets sent to landfill
but, as discussed in paragraph 32 above, separate food collection
services for domestic households have varying levels of success
and can be disproportionately costly. We also received evidence
that it is very difficult to separate food waste out at the right
quality, quantity and in the right place to feed an AD plant.
Mechline Developments Ltd were particularly concerned about separate
food waste collections for onward use as AD feedstock and identified
a range of associated risks, including contamination levels; carbon
emissions from the consequential higher road traffic; and reducing
the incentive to minimise food waste and redistribute edible food.
69. In certain circumstances, purpose-grown crops
or biomass such as maize, grass silage or whole-crop cereals are
used as a feedstock for anaerobic digesters. Defra's Anaerobic
Digestion Strategy and Action Plan 2011 explains that:
it is not the Government's policy to encourage
solely purpose-grown crop-based AD systems, particularly when
these are grown to the exclusion of food producing crops, or where
growth of these crops might adversely affect biodiversity or deter
optimal use of waste materials.
70. We agree with Defra that the greatest benefit
of anaerobic digestion is in dealing with waste feedstock, not
purpose-grown crops. However, sourcing appropriate waste feedstock
on a consistent basis remains a significant challenge for AD operators
and more work is needed to address the issues surrounding separate
food waste collections.
71. The Government must find ways of diverting
more food waste out of the residual waste stream by methods which
are economically and environmentally viable and suitable to local
circumstances. Where food waste is separately collected it should
be treated at local AD plants whenever possible to address the
problem of sourcing waste feedstock.
72. Anaerobic digestion produces biogas and digestate.
Biogas can be used to generate renewable heat and power, which
helps to reduce the use of fossil fuel and reduce greenhouse gas
emissions. Digestate is rich in nutrients, so it is a valuable
bio-fertiliser which can be used instead of fossil fuel-intensive
fertilisers. The nutrient composition of the digestate depends
on the feedstock but must comply with the PAS 110 standard to
meet with national requirements in Britain. Meeting this standard
requires source segregation of food waste. However, CIWM highlighted
that despite the requirements, the markets for digestate were
not always secure as demand was seasonal and the nutrients in
digestate were needed in different ratios and quantities in different
soils. This can be compounded by a lack of confidence by some
important agricultural customers in the digestate, due to the
lack of information available about its long-term effects.
As further explained by Defra:
digestates derived from purpose-grown crops,
food wastes and other inputs are often regarded as novel by the
market, which is wary of accepting them until evidence of their
quality and benefits can be provided.
73. In order to improve the confidence of agricultural
customers and improve the stability of the market for digestate,
we recommend that further research is undertaken to determine
the long-term effects of AD digestate on the quality and composition
of soil and crops.
Incineration with energy recovery
74. Incineration with energy recovery is generally
placed higher up the waste hierarchy than landfill in terms of
environmental performance and is considered by Defra to be the
best waste management option for most genuinely residual waste.
It is a waste treatment process where organic substances contained
in waste materials are burnt and converted into ash, flue gas
and heat. The incineration bottom ash goes to landfill or can
be reused as construction aggregate material; the flue gases must
be cleaned of gaseous and particulate pollutants before being
dispersed into the atmosphere; and the heat can be used as heat
and/or to generate power.
75. Incinerators with energy recovery are typically
cited to have electric efficiencies of up to approximately 27%
but can be much more efficient if the heat energy is used for
local district heating or nearby industrial processes. Steve Lee,
CEO of CIWM, referred to the inclusion of heat recovery as the
"secret difference between being 25% or 26% efficient and
75% to 80% efficient".
However, in most instances, electricity alone is recovered from
incineration as it can be easily distributed and sold via the
national grid. Dr Colin Church, Director of Resource, Atmosphere
and Sustainability at Defra told us that there are currently 42
incinerator plants in England and all those that Defra supports
have the capacity to use heat; but only a very small number"a
76. The Government should encourage the use of
heat outputs from incinerators for local district heating for
buildings and/or for industrial processes to gain maximum efficiencies
from incineration processes. Defra should explore the barriers
to using heat recovery and collaborate with DECC and DCLG to ensure
that Government policies, planning permissions, permits and incentives
are all aligned to enable higher efficiencies for incineration
77. The use of incinerators for waste treatment can
be controversial due to worries over health and environmental
risk from the pollutants that can be released into the atmosphere
(most significantly, dioxin and furans) and concerns that availability
of incinerator capacity could have a negative impact on recycling
rates. UKWIN told us that recycling is harmed by incineration
for various reasons, including the presence of incineration capacity
and government subsidies for incineration discouraging investment
in recycling, the long-term lock-in of money and feedstock to
existing and proposed incineration capacity, and the fact that
the true costs of incineration are not reflected in the price
UKWIN also provided us with data showing an apparent correlation
between high rates of incineration and low rates of recycling.
78. In response to the concerns about harmful emissions
and environmental impact, witnesses including ESA and CIWM assured
us that this is one of the most tightly regulated industrial process
in Europe. Public
Health England's position is that modern, well-managed incinerators
make only a small contribution to local concentrations of air
pollutants and that the risks to human health from these plants
are likely to be very small and not detectable.
79. Concerns about the possible negative impact on
recycling rates tend to focus on the typically long-term contracts
entered into by local authorities for the supply of waste feedstock
to the incinerator. Once the incinerator infrastructure exists
it needs to be fed with waste so local authorities commonly agree
to supply a minimum or fixed tonnage of waste to the incinerator
(or pay a fine). This is referred to as "put or pay".
The commercial risk of higher recycling rates and changing waste
legislation or policy (i.e. banning incineration of food waste)
is therefore also taken by the local authority. Some witnesses,
such as Zero Waste England and UKWIN, argued that "put or
pay" leads to a perverse incentive for local authorities
to withdraw recycling schemes to ensure that they can comply with
their contractual obligations for waste supply to incinerators.
Similarly, Oxfordshire County Council told us that they have no
minimum tonnage contracted with the energy-from-waste facility
they use which enables the council to reduce and recycle as much
waste as possible. Consequently, its recycling rates are around
80. Conversely, the Resource Association believe
high levels of recycling are not incompatible
with the use of thermal treatment for some municipal waste alongside
the near elimination of landfill as an option, but we should be
wary of the problem of over-capacity in incineration now being
faced by some European colleagues.
This view is reinforced by evidence showing that
the four top performing EU countries with over 50% recycling rates
also operate some of the highest levels of energy-from-waste capacity.
81. When we asked the Minister how the Government
ensures that only genuinely residual waste is sent to incinerators,
he told us that the key pressure is gate feesi.e. the charge
that must be paid to dispose of waste in an incineration facility.
However, we are concerned about the effectiveness of this singular
mechanism following evidence we received about "put or pay"
contracts and negative impacts on recycling rates.
82. In most cases, the environmental benefits
of recycling household waste are higher than sending it to energy-from-waste
technologies such as incineration. However, we do not think that
high levels of recycling are incompatible with the use of incineration
for genuinely residual waste.
83. We urge Defra to ensure that waste sent to
energy-from-waste plants such as incinerators is only genuinely
residual waste. We ask Defra to assess whether the use of gate
fees is sufficient to achieve this aim and to confirm whether
additional interventions, such as regulatory requirements to remove
dry recyclables or higher gate fees have been fully considered.
84. During 2012 and 2013, 595 incidents of fire were
reported at privately operated waste management sites. This represents
an average of one fire for every 18 such sites.
Waste fires can burn for days and have significant impacts, including:
- polluting the environment;
- harm, cost and inconvenience caused to local
- public health issues;
- firefighter safety; and
- straining the resources of local authorities,
the fire service and the Environment Agency.
In addition, it is often valuable recyclates which
burn causing significant financial loss to the owner of the site.
85. The Environment Agency regulates waste management
facilities, including monitoring and enforcement issues, and licensing
and monitoring transport of waste. The operator of a waste management
site holds a permit issued by the Environment Agency, setting
out the measures that must be taken to minimise pollution and
harm to health, including carrying out risk assessments and putting
in place an accident plan to reduce fire risk. In response to
the numerous occurrences of waste fires, the Environment Agency
issued fire safety guidance for waste and recycling site operators
in October 2013.
The guidance addresses fire prevention as the key for operators
of waste sites. It recommends keeping sources of ignition at least
six metres away from stacks of combustible material and introducing
a regular maintenance and inspection programme. Storage times
is another area identified as a risk. The guidance sets a six-month
limit on how long RDF and smaller fractions of waste (known as
'fines') can be stockpiled.
86. More recently, the Chief Fire Officers' Association
addressed the All-Party Parliamentary Group for Fire Safety and
Guidance to inform members of both Houses of the collaborative
work being undertaken with the Environment Agency and the waste
sector to develop a fire code of practice; to share data and information;
and to revise national operational guidance on fighting fires.
87. The Minister acknowledged that there are issues
around the resources of fire and rescue services, as well as the
fact that some operators are not complying with the conditions
of their permits. He also confirmed that Defra has secured an
extra £5 million to deal with waste crime (including waste
fires) and was working with the Environment Agency to work out
how to make the best use of that money.
In order to tackle the problem of waste fires, he explained that
"it is important that we get tough on the operators that
are not living up to their permits".
88. We commend the work of the Environment Agency
assisting operators with the problem of waste fires and we support
the work being undertaken by the Chief Fire Officers' Association
in relation to this serious issue.
89. We expect Defra and DCLG to take action to
address the frequent occurrence of fires at waste management sites
and to support the development of the fire code of practice by
the Chief Fire Officers' Association. Defra must ensure that additional
resources are deployed in the best way possible to monitor and
enforce the conditions of the requisite permits.
79 Defra [WME 0072] para 4.7 Back
SITA UK [WME 0075] para 6 and 7 Back
Chartered Institution of Wastes Management [WME 0073] para 52 Back
National Association of Waste Disposal Officers [WME 0011] para
See Q76 [Dan Cooke] Back
Defra [WME 0072] para 4.7 Back
Defra, Refuse-derived fuel market in England: call for evidence,
12 March 2014 Back
Defra [WME 0072] para 1.5 Back
Anaerobic Digestion and Biogas Association [WME 0060] para 5 Back
Ibid., para 6 Back
See Q24; Resource Association [WME 0068] para 15; Eunomia Research
& Consulting [WME 0055] para 32 Back
WRAP, Love food hate waste; Q352 and Q21 Back
Mechline Developments Ltd [WME 0079] paras 4, 5, 7 and 8 Back
Defra, Anaerobic Digestion Strategy and Action Plan, para 55 Back
Chartered Institution of Wastes Management [WME 0073] para 57 Back
Defra, Anaerobic Digestion Strategy and Action Plan, paragraph
Defra [WME 0072] para 6.5 Back
Defra, Incineration of Municipal Solid Waste, February 2013, p13 Back
UKWIN [WME 0025] para 2 Back
UKWIN [WME 0025] para 6.40. For example, based on 2012/13 data,
Westminster City Council incinerate 82.46% and recycle 13.15%
of collected waste. Back
Q31 and Q34 Back
Public Health England Position Statement, Impact on health of emissions to air from municipal waste incinerators
Oxfordshire County Council [WME 0013] para 3.1 Back
Resource Association [WME 0068] Executive summary Back
SITA UK [WME 0075] para 2; Veolia [WME 0050] para 5.3 Back
HC Deb, 8 April 2014, Col 211W
[Commons written answer] Back
Environment Agency Technical Guidance Note (TGN7.01) Back