The Waste & Resources Action Programme (WRAP) has today (24 April) issued sampling and testing guidance for material facility (MF) operators, to help them comply with the requirements of the new Material Recovery Facility Regulations (MRF Regulations).

Under the MRF Regulations (part of the Environmental Permitting (England and Wales) (Amendment) Regulations 2014), from 1 October 2014, MRFs processing more than 1,000 tonnes of mixed waste per annum will have to test the composition of samples of the material they put into the sorting process (such as glass, metal, paper and plastic), and the useable output, and report them to the Environment Agency (for MRFs in England) or Natural Resources Wales (for MRFs in Wales).

It is hoped that by providing 'robust' data on MRF inputs and outputs, the UK could improve recyclate quality.

Guidance details

Developed by a steering group comprising the environment departments from each of the UK nations – as well as several industry stakeholders and representatives, including Viridor, SITA UK, the Resource Association and Resource Futures – WRAP’s ‘non-statutory, good practice guidance’ has been produced to ‘ensure that the sampling of materials and testing of composition carried out under the regulations is undertaken by MFs in England and Wales to a high and consistent minimum standard using recognised and accepted procedures’.

According to the ‘Sampling and Testing Guidance for Material Facilities’, sampling materials at material facilities (such as MRFs and commercial waste treatment operations, and transfer stations where materials similar to household wastes are sorted into two or more ‘specified output materials’) can help:

• provide the market with the information and transparency necessary to improve recyclate quality whilst at the same time achieving compliance with the regulations;
• demonstrate that sorted recyclables leaving the facilities are suitable for ‘high-quality recycling’ applications in line with industry best practice (thus demonstrating compliance with Article 11 of the revised Waste Framework Directive);
• improve processes and cost efficiency by using data on the quality and composition of materials to manage sorting facility performance and ‘inform investments into operations and technical developments’;
• improve the quality of input materials by providing feedback to suppliers on input material quality to help them improve their collection systems and associated communication activities; and
• increase revenue from output materials by ensuring that output materials ‘meet or exceed reprocessor specifications thereby reducing the likelihood of reprocessors seeking financial recompense due to poor quality, and potentially also increasing their market value’.

Complementing and expanding on summary guidance released by the Department for Environment, Food & Rural Affairs earlier last month, the guidance not only outlines how operators should be collecting samples, but also provides information on:

• the equipment needed to take samples;
• best/good practice for sampling and testing;
• details on how to calculate the relevant statistics (such as deviation) and data input templates;
• suggestions for staff training, including health and safety; and
• suggestions for additional sampling ‘that can be undertaken to help improve the management and performance of a facility’.

WRAP identifies that both incoming and outgoing mixed waste material must be sampled to identify ‘target material’, ‘non-recyclable material’ and ‘non-target material’.

It suggests that although sampling of the residual waste fraction, e.g. MRF residues, is not required under the regulations, it is ‘considered good practice’ as it allows operators to:

• identify the types and quantity of target materials that are being lost during processing (and thus ‘improve operational practice and identify shifts where the equipment is being operated incorrectly and where additional training may be required’);
• identify common types of non-target and non-recyclable material and pass this information back to suppliers for use in communication campaigns;
• perform ‘mass balance calculations’ that might be used for business planning purposes; and
• assess compliance with the legal duty to apply the waste hierarchy as a priority order, by not sending material on to disposal or energy recovery if it can be recycled.

Sampling sizes

Looking to sampling itself, WRAP highlights that although minimum samples are required for certain waste streams, a full sample must be collected in one go.

The document reads: ‘[I]t is not acceptable to take smaller sample sizes at more regular intervals in order to collect a sample, for example it is not acceptable to take six small samples of 10kg to obtain the required 60kg sample size for incoming mixed waste material.’

WRAP says that the reasoning for sampling this way is due to the fact that the size of the samples affects the amount of variation that will show, and larger samples will have ‘less variability, [and will be] more representative of the actual material’.

The guidance also recommends that MF operators ensure the sampling and testing of materials is an ongoing process and that inputs from different suppliers are assessed.

The document goes on to provide step-by-step guidance on suitable minimum methods for obtaining representative samples of incoming mixed waste material and specified output materials, which include:

• planning the sampling schedule and ensuring it is as representative as possible by taking samples at different time, days, and shifts;
• isolating the material in an area that has been cleared of all other material and avoiding contamination;
• taking a random sample and avoiding contamination of the sample (a detailed methodology for this is also included in the guidance);
• labelling the sample with the date of sample, time of sample and sample weight; and
• transporting it to the testing area using a pallet truck or fork lift truck, or, if the container the sample is in has wheels, pushing it.

WRAP adds that samples should be tested as soon as possible after being taken to prevent degradation, and thus should not be taken and stored throughout the week for testing at the end of the week.

Caluclating deviation

Outlining how to calculate standard deviation of the average percentage composition level of target materials in Excel spreadsheets (using =STDEV.S(plus results)), WRAP outlines that the aim for suppliers should be to have 'a high percentage of target material in incoming mixed waste material with a low standard deviation', and for MFs to have 'a high percentage of target material in outgoing materials with a low standard deviation'.

The standard deviation can then be used to 'estimate the confidence intervals of the reported average percentage composition for target materials'.

Good practice examples

Further to this, the guidance outlines several examples of good practice facility operators can take.

Good practices in sampling include:

• ensuring that staff undertaking the sampling and testing are fully trained and have more than one person trained;
• modifying the day and time that incoming samples are taken so that samples are not always taken from the same collection route (which may have particular quality characteristics);
• modifying the day and time that output samples are taken to ensure that variances in staffing, operations and input materials are reflected;
• automating the sampling wherever possible to ensure samples are taken randomly and without human intervention, for example by taking samples directly from a suitable conveyor;
• when sampling bagged materials, picking a range of bags sizes and weights;
• ensuring that samples are correctly labelled and stored in a way that protects them from cross contamination with other materials and the weather;
• marking containers so that handlers know by sight approximately how much material is required for the sample (dependant on weight of material); and
• undertaking regular spot checks to ensure that sampling is being undertaken correctly.

Good practices in testing include:

• locating containers for sorted materials close to the operatives and using a suitably sized table, set at a height where sorting can be done comfortably;
• providing a sufficient number of containers for each operative to sort the sample into all the required material categories;
• ensuring the operatives undertaking the testing are fully trained (including being trained in safe systems of work) and understand the different material categories;
• placing full containers near the scales ready for weighing; and
• keeping containers clean and dry to avoid weight distortion.

Resources for MRF Operators

As well as the guidance, a summary document, Recovering value from MRFs, presents an overview of of key aspects in the specification, operation and costs of MRFs. It draws together the results of three separate studies commissioned by WRAP:

• A MRF comparison study, which looked at material sorting practices and technologies employed at a cross-section of MRFs in England, the USA and Europe;
• MRF cost model and user guide – a costing tool for different materials sorting options; and
• Contractual arrangements between local authorities and MRF operators, which reviewed and assessed existing contractual relationships between MRF operators and local authorities across the UK.

There are also reports, guidance and case studies for municipal MRF operators including:

• MRF output material quality thresholds: a report on materials quality standards, quality measurement techniques and their implementation by UK MRFs and materials reprocessors;
• MRF quality assessment study: material quality assessment of municipal MRFs within the UK; and
• Quality management systems (QMS) for municipal MRFs: practical guidance and templates to assist with the implentation of a QMS.

‘Ensuring a high-quality, consistent approach to sampling’

Speaking of the new guidance, Steve Waite, Sector Specialist for MRFs and Materials at WRAP, said: “The WRAP non-statutory sampling guidance has been developed to support the MRF Regulations which came into force on 5 March 2014, and which requires materials facilities to begin sampling their mixed waste inputs and graded outputs from 1 October 2014.

“This best practice guidance aims to explain the requirements of the regulations and will help ensure a high-quality, consistent approach to sampling. The sampling techniques outlined can be adapted to suit individual MF circumstances. The document was developed with support from a steering group consisting of government, regulators, the waste industry and reprocessors.”

Read WRAP’s ‘Sampling and Testing Guidance for Material Facilities’.