1 June 2012

Diversion from landfill

Tara Donaghy of McGrath Group explains how incremental changes in technology and government support helped her company achieve its goal to develop a fully sustainable recycling system that diverts all but hazardous waste from landfill.

In March 2008 the Chancellor, Alistair Darling announced the biggest hike in landfill tax since its inception in 1996 a whopping 8 per tonne increase taking it beyond the 30 barrier for the first time.

This, combined with increasing environmental pressure from industry to provide more sustainable waste management solutions, provided the stimuli for the McGrath Brothers, David and Patrick, to set-out plans to develop a completely sustainable recycling solution that diverts all wastes they handle from landfill. With advances in technology and pre-recession funding available for environmental developments they figured a genuine Zero-to-Landfill solution could be developed in 4 years.

A bespoke wrapping/baling plant installed in 2011 allows residues to be collected and sent for energy recovery

A bespoke wrapping/baling plant installed in 2011 allows residues to be collected and sent for energy recovery

At the time the McGrath Group was recycling around 75 per cent of the 370,000 tonnes of materials it was processing through its two licensed Recycling Facilities in London (Hackney) and Essex (Barking).

The companys association with the construction industry and, in particular, demolition (Demo One was assimilated into the Group in 1981) had cultivated the philosophy of material as a resource i.e. an asset to be exploited rather than problem to be disposed. After all, the disposal of waste is a demolition contractors single biggest cost so it made commercial as well as environmental sense to re-use or recycle as much of it as possible.

Concrete

McGrath were believed to be the first company in the UK to set-up a permanent concrete crushing plant in the late 1970s and in 1985 became the first to have its recycled aggregate certificated to Department of Transport standards. The development of the UKs first licenced aggregate washing plant in 2007 enabled the McGrath Group to decontaminate and therefore recycle all inert construction and highway utility wastes which resulted in a quantum leap in our recycling rates from 50 to 75 per cent.

We successfully applied to the Waste & Resources Action Programme (WRAP), a non-profit organisation backed by Government and EU finance, for funding to develop two state-of-the-art recycling facilities at our 11-acre site in Barking.

Timber

A 250k grant was provided to design and install bespoke plant and equipment to process timber products on-site. The facility consisted of specially-designed equipment to remove contaminants such as screws, bolts etc and two shredding machines that process wood into various grades.

The facility gave us an auditable process which enabled us to provide material for a number of uses. We grade materials according to the system devised by the Wood Recyclers’ Association. Grade A (clean wood) derived from pallets, retail packaging and building offcuts will be supplied as feedstock for the manufacture of consumer products such as animal bedding and horticultural mulches. Grade B, which mainly comes from demolition arisings, is provided for industrial wood processing operations including the manufacture of panel products, chipboard and medium density fibreboard (MDF).

Funding from WRAP facilitated the development of the company's bespoke timber recycling facility in 2008

Funding from WRAP facilitated the development of the company’s bespoke timber recycling facility in 2008

Timber which is coated with paints coatings, glues, and other coverings will typically be classed as Fuel Grade (C) and used as Biomass fuel for use in the generation of electricity.

We also obtained a further 350k funding from WRAP to develop our rubber recycling facility at Barking to accommodate a range of rubber products including playground surfacing, used tyres and produce different grades of processed material.

Tyres

Bespoke equipment was designed to enable us to remove rims from tyres and the shredding plant was customised to allow us to produce material to various sizes from 100mm diameter to 25mm, 8mm and crumb size.
We also enhanced the electro-magnetic conveyor-system that removes metal contaminants and invested in a new mechanical process for collecting and baling wire and small metals removed from the rubber shred which along with the metal rims is assimilated into our ferrous metals recycling process.

These enhancements allowed us to obtain accreditation to the industry standard PAS 107 and expand our customer-base for processed rubber. Different grades of processed material are now provided for equestrian arena surfacing and manufacture of fibre matting for outdoor playgrounds. Our work with the National Industrial Symbiosis Programme (NISP) resulted in us supplying rubber aggregate to provide infill and drainage material for the Cambridgeshire Guided Busway scheme.

Picking station

The next major development in diverting wastes from landfill occurred in October 2010 when we installed a picking station at our Barking MRF to segregate the increasing volumes of office and household wastes generated by our move into the commercial sector.

The facility, which was fully integrated into our existing mechanical sorting system, feeds loose materials via a conveyor belt into a cabin with 30 stations where operatives remove items that are placed into discrete material bays where they are baled and removed for reprocessing. We also developed a supply-chain of partners that could provide closed-loop techniques to reprocess these commercial wastes such as paper/card, metal (cans) and plastics into new products.

These initiatives had raised our recycling rates to within 9% of the magic 100 by the end of 2010. To reduce the gap further we needed to find a way of addressing the increasing volumes of food-contaminated waste that our municipal contracts were generating.

The installation of a picking station enabled McGrath to segregate and recycle household and municipal wastes

The installation of a picking station enabled McGrath to segregate and recycle household and municipal wastes

Nearly three-quarters of food waste currently goes to landfill but as much as 90% is recoverable and can be recycled.

We approached a number of food recyclers with view to setting-up a joint-venture to provide a sustainable solution for black bag waste. We selected Midlands-based PDM as they had developed the most robust and advanced techniques for segregating packaging and other contaminants.

Large items of plastic, glass or paper packaging or contamination are separated at our MRFs and the residue is collected and removed to PDM where further de-packaging is carried out. Proteinrich food waste puree is typically pumped into a combined heat and power (CHP) plant while non-protein rich material is pasteurised and pumped into anaerobic digesters.

Residues

By the time we expanded our picking station to accommodate 12 new bays at the end of 2010 the organisations recycling rate stood at 95%. The only obstacle now preventing us from diverting all material from landfill were the residues generated at the MRFs. These consist of small particles that have passed through our entire sorting system and cannot be segregated into individual material streams. Discussions with a number of energy-recovery specialists convinced us that a solution could be found if we could supply the material in a robust format.

In June 2011 we invested nearly half a million pounds in a state-of-the-art baling/wrapping system that would enable us to collect residues and package them in strong plastic bales that could be transported in-situ to be processed using Combined Heat and Power technology. This proved to be the final piece of the jigsaw and following a thorough test period and scrutiny of data we were ready to formally announce in February 2012 that our four-year journey to Zero-to-Landfill was complete.

Apart from the environmental achievement the considerable commercial benefits we can pass on to our clients by recycling all of their non-hazardous wastes has taken on added significance since April when landfill tax increased to 64 per tonne.

0COMMENTS

To post your comment, please login or signup.

Login Sign up