Contamination - how the scheme works
Finding your way round the Maximise Recycling Scheme
When a material is presented in the incorrect bin, or is
presented in the bin incorrectly, then this is referred to as
‘contamination’. Examples of contamination include placing food in
the recyclables bin instead of the compostables bin, and
recyclables which have been placed into the recyclables bin inside
a plastic carrier bag (bagged), rather than loose.
Recyclables
The recyclables collected from the kerbside are taken to a
Materials Recycling Facility, or MRF, in Tilbury where they are
sorted both mechanically and manually. If the facility sees that a
vehicle arrives with significant levels of materials which they
cannot take to their re-processors (i.e. the facilities that
actually recycle each type of material), or there are any black
sacks or bagged materials then they may not let the vehicle tip as
they will be unable to handle the material.
The cost of contamination
The Materials Recycling Facility have reported to Rochford
Council that an average of 117 tonnes per month of materials
collected in the recyclables bin is actually not recyclable. They
are unable to handle the material and it therefore has to be sent
to landfill. This represents a cost to the Council of approximately
£8500 per month- over £100,000 per year.
Why can’t the MRF take black sacks?
The problem with black sacks is that they are generally used as
a standard way of disposing of general rubbish (non-recycling). If
a facility sees a black sack it cannot take the risk and assume
that it contains recycling, as it may also be likely that it
contains non-recycling. The MRF therefore specifies that they
cannot take black sacks so that they can minimise the chances of
contamination. Black sacks can therefore only be placed in the
non-recyclables bin.
Why can’t the MRF take bagged recycling?
Shopping carrier bags are too small for the bag splitter found
at the beginning of the sorting process. This means that the
splitter may not necessarily make contact with the bags. Therefore,
there is a significant chance that they may get missed by the bag
splitting stage and the material inside them does not get separated
and can not be sorted properly. The MRF can however take loose
plastic shopping carrier bags so these can be placed in the
recyclables bin loose.
Why can’t the MRF handle the contamination?
The types of machinery used to sort the various materials use a
variation of technologies to differentiate plastic bottles from
plastic packaging, or paper from plastic, for example. Introducing
another material into the sorting process without calibrating the
machinery to detect that material can cause significant problems.
‘Contaminants’ also result in the plant having to be shut down for
periods of time so that the machinery can be cleaned (for example
if food has got on there, or dirty recycling has stained it).
Contaminants also affect the quality of the end material- for
example, food on newspapers is not ideal when they are destined to
be recycled back into newsprint.
It is because of all these issues that we may have to leave your
bin uncollected if there is anything in it which cannot be
recycled.
My bin only had a few wrong items in - why can’t it be
collected anyway?
The problem with even small amounts of contamination is that
when this is multiplied by the number of households on a round,
which can reach in the region of 1500, then you are looking at
significant levels in one vehicle load. This is why the operatives
are so careful about what they collect.
See the related documents below for photos of contaminated
recycling at the MRF before it has been sorted.
Compostables
Compostables collected from the kerbside are taken to an
In-vessel composting (IVC) facility. In-vessel composting
facilities can compost biodegradable materials ranging from grass
cuttings to raw meat because the material is composted in enclosed
‘vessels’ where everything is regulated and controlled closely. Air
temperature, moisture levels and air flow are all monitored to
optimise the composting process.
Because it is a process which composts down biodegradable,
organic materials, then it is important that other materials, such
as plastics, glass or cans, for example, do not find their way into
the compostables bin. For similar reasons as the MRF, the facility
will not accept material that is contaminated as they will not be
able to handle it, and it will affect the quality of the end
product- nobody wants to buy compost which has flakes of plastic
bags in it, or metal cutlery!
Why can’t the IVC take black sacks?
The problem with black sacks is that they are generally used as
a standard way of disposing of general rubbish (non-recycling). If
a facility sees a black sack it cannot take the risk and assume
that it contains recycling, as it may also be likely that it
contains non-recycling. The IVC therefore specifies that they
cannot take black sacks so that they can minimise the chances of
contamination. Black sacks can therefore only be used in the
non-recycling bin.
Why can’t the IVC take material bagged in plastic shopping
carrier bags?
This is because plastic carrier bags are not BIO-degradable.
Beware of sacks which say they are degradable - this is misleading
as all plastic degrades and breaks down into smaller pieces of
plastic over time.
Biodegradable material is generally organic matter, and
biodegradable liners are made from either cornstarch or paper so
that they break down chemically and become part of the compost
itself.
How can I be sure whether a sack or liner is
biodegradable?
The packaging tends to say whether or not they are
bio-degradable. If they just say that they are degradable then do
not use them in the compostables bin. You can also check whether
they have the seedling symbol on them
Why can’t you collect compost or soil in the compostables
bin?
This is because it is a waste of money and resources to both
collect and reprocess soil, as it is ultimately the material that
the composting process is hoping to produce at the end of the
process. Please reuse soil wherever possible, or small amounts can
be recycled at the Recycling Centre for Household Waste at Castle
Road, Rayleigh. Please contact Essex County Council’s Waste &
Recycling helpline on 0845 603 7625 for more information.
See the related documents below for photos of contaminated
compost once the composting process has been completed. It is clear
from the pictures that black sacks, cartons and knives do not break
down and remain identifiable even once all the material has been
through the facility.
See the related documents below for photos of quality compost
without any contamination once compostable material has been
processed at the IVC.
If your bin is found to be contaminated then it will be left
with a contamination sticker on it. Please remove this sticker and
remove any contaminants before the next scheduled collection. If
your bin is found to be continually contaminated, then your bin
will not be collected.
It is therefore extremely important that the correct materials
are presented in the correct bins.
If a contamination sticker has been stuck to your bin and you
would like more information then please contact SITA UK (the
Councils collection contractors) on 01702 533880.