What happens to my recycling and residual waste once collected from the kerbside?
Recycling and residual waste material collected in Powys is delivered to the nearest regional transfer station to be bulked prior to onward haulage to reprocessors.
How is it processed?
Where possible, all of Powys' kerbside materials are sent for processing within Wales, but some material is processed in England. No material travels further than this to be completely recycled or disposed of.
Food Waste
Our County's food waste is currently taken to anaerobic digestion (AD) plants in Bridgend, Staffordshire and Oxfordshire.
Here, bacteria breakdown the solid food waste in the absence of oxygen. This is a highly efficient process allowing for upwards of 98% of inputted food waste to be directly recycled.
The end product is fertiliser feedstock for direct reuse in the agricultural sector. Due to the AD process, a considerable quantity of methane is also produced, which is harvested and used as biogas to generate electricity for the National Grid.
All of the recycling processes, as well as the use of the resulting gases, is conducted at the same site. The remaining material (less than 2%, typically made up of large bones, plastic and other contaminants that did not break down during the slurry process) is sent for incineration, also to produce electricity for the National Grid, but at various facilities in Wales and England.
There is a further recycled component from the bottom ashes produced post-incineration, which is used as a component in cement manufacture.
Paper/Card
Collected mixed, our kerbside paper/cardboard is currently sent to a large paper producing mill in Kent. The material is turned back into pulp to be fed back into the manufacture of new paper and cardboard.
This is also a very efficient process with upwards of 94% of this material being recycled directly back into paper and card. Around 3-4% consists of non-recyclable paper/cardboard, but although this can't be turned back into paper or cardboard, it is still recycled, being sent for composting instead.
The remaining 2-3% consists of adhesive tape and staples etc., separated from the paper and cardboard. This is sent to landfill and/or incineration, the latter provides energy to power cement manufacturing plants.
Glass
Our glass is currently sent to a reprocessor with facilities in Cwmbran, Torfaen and Ellesmere Port, Cheshire.
The majority of our material ends up in Cwmbran, with Ellesmere primarily used when the former is at capacity. At these sites, the material is crushed and undergoes magnetic and 'eddy current' sorting to separate any metal components from the glass. Further mechanical sorting removes plastic or paper (from bottle lids, caps and labels etc.). The crushed glass, known as 'cullet', is then either sorted by colour, then made into new glass bottles or containers, or more commonly is sent mixed to fibre glass insulation manufacturers as feedstock for their production process.
For poorer quality material, the glass can be graded by grain size and used as a component in construction aggregates. Given the very small size, poor quality and mixed composition of the paper/plastic fraction, this is usually incinerated for electricity production but can sometimes be landfilled. As with other incinerated reject material, the bottom ashes are recovered and used as raw material in cement manufacture. The metals are bulked up and sent on to reprocessors to be shredded and smelted back into metal feedstock.
The amount of incinerated/landfilled material rarely exceeds 5% resulting in an average recycling rate for our glass material collected of upwards of 95%.
Cans, Plastics and Cartons
Our co-mingled cans, plastics and cartons are delivered to our transfer station in Llanwern, Brecon, where magnetic and 'eddy current' separation is used to isolate the steel and aluminium cans, respectively, from the plastics and cartons. Obvious non-recyclable material is hand-picked from the stream and mixed with the other residual waste on site for disposal. Additionally, the cartons are hand-picked and separated for recycling, and the remaining material is a relatively clean plastics stream. These four recycling sub-streams are then baled and sent for further processing.
The aluminium cans are shredded and smelted back into new aluminium feedstock at facilities in the North of England. They are most commonly turned back into aluminium cans, but can also become car parts and other aluminium items.
The steel cans are currently processed by a metal reprocessor in South Wales, and are similarly shredded and smelted into new cans or other steel products.
The food and beverage cartons are collected by ACE UK, which is a consortium of the main composite food and beverage carton manufacturers operating within the UK. They have created a dedicated facility in Halifax, Yorkshire that shreds and pulps the cartons down to delaminate the various plastic film, foil and paper layers of the carton structure. Each component can then be separated, with the plastic being recycled back into film feedstock, the foil being sent for smelting, and the paper is turned back into sheet feedstock at the adjacent paper mill on site. Lids and hard plastic spouts are also separated for recycling back int plastic flake or pellets ready for remanufacture.
The plastics are currently taken to a Materials Recovery Facility (MRF) in Greater Manchester, which optically separates them into the individual polymer types, where possible. The same company is also able to directly recycle the recovered PET [1] into new products at their sister site in the Newport. This polymer typically makes up around 35% of the plastics stream and is shredded into pellets which are melted and extruded into new products.
HDPE [2] milk bottles are sent onward to a processor in Redcar near Middlesbrough and are directly recycled back into new milk bottles. Any other HDPE [2] material is sent on to a company in Lincolnshire that make plastic pipework for the civil construction industry.
PP [5] pots, tubs and trays are sent to a company in Warwickshire who clean and shred them into pellets, which are provided as feedstock to manufacturers of PP sheet rolls to be used to create new pots, tubs and trays.
Despite Powys sorting the cans from the plastics at our MRF, some metals do make it through to the plastics stream, and so there is also a minor output of metal material from this company's MRF, which is also sent for recycling.
Any remaining material, such as PVC [3], PS [6], non-recyclable coloured plastics, fines (sub-50mm material) and other reject (paper labels, film bottle wraps etc.) are sent to be turned into Solid Recovered Fuel. This is then used by various UK Energy from Waste facilities or cement manufacturers to either add electricity to the National Grid, or power their on-site kilns, respectively. Any ashes produced from incineration are recycled into construction-ready aggregates, or used as raw material replacement within the cement manufacture itself, adding an additional layer of material recovery. Because the proportions of the different plastic polymers in the mixed plastics stream varies month by month, so too does the recovery rate of this material stream. Typically, it will vary between 75 - 90% and is the most variable kerbside material stream in terms of quality and recyclability.
Garden Waste
Our garden waste is currently taken to a composting facility in Carmarthenshire.
Here it is shredded prior to undergoing 'open windrow' composting. This process involves mixing the shredded material and storing it in large openair bays.
The material is turned periodically to aerate it and allow full breakdown throughout the load, and the process can take several months (typically around 16 weeks) to produce the final compost output.
Residual Waste
As of November 2021, none of our residual (non-recyclable) waste goes to landfill anymore. Instead, it goes to an Energy from Waste (EfW) facility in Merseyside. Here, the waste is incinerated to produce heat, the heat is used to boil water, and the resulting steam is used to drive a turbine which generates electricity for the National Grid.
This is a very traditional process for electricity generation; the same as is utilised by natural gas, coal, biomass and nuclear power plants, but here uses household and business residual waste as the fuel.
Incinerating any material is not a clean process, and so the plant utilises 'scrubbers' to clean the exhaust gases as much as possible prior to being expelled.
This involves the gases being passed through a mix of ammonia, lime and activated carbon that captures some of the harmful gas compounds, reduces the acidity of the remaining gases, and adsorbs the heavy metals and dioxins present in the exhaust gases. This drastically reduces the levels of pollutants expelled to the atmosphere, though it does not eliminate them entirely.
The leftovers from this process are called Air Pollution Control Residues (APCR), and are, at this stage, considered hazardous waste. However, this material is sent to a specialist and pioneering company, which is able to render this material safe and recycle it. They do this by breaking apart the larger harmful molecules into smaller ones, and binding them up into engineered aggregate material, which is effectively a manmade limestone material. This process is called Accelerated Carbonation Technology (ACT), and the outputs can be used as aggregate material in road-building and concrete manufacture, for example.
Naturally, not everything contained within residual waste is combustible, or at least not entirely, and so there is an output from the incinerator of ashes known as 'Incinerator Bottom Ashes (IBA)', as well as concentrated metals.
Having had most of the harmful heavy metals and other compounds vapourised and expelled from the residual waste during incineration, the IBA is not considered hazardous. As such, this is sent on an aggregates processor to be graded by size, and like the APCR, is also used as road construction base fill material, raw material in cement manufacture and raw material for the manufacture of bricks, among other things.
The metals undergo magnetic and 'eddy current' separation to isolate the ferrous (iron-containing) and non-ferrous grades, which are sent on to smelting facilities to be turned back into new metal feedstock and products.
The proportion of residual waste that remains as APCR, IBA and metals after incineration varies over time, depending on the composition of the input material. Typically however, the APCR constitutes between 2 and 6%, the IBA between 13 and 20%, and the metals between 1 and 4%. As such, the recovery rate of the incineration process from the recycled IBA/APCR and metals can vary between 15 and 25%. This means that as well as providing an energy source, some of the residual waste is also recycled.