Waste not, want not

The government’s aspiration for a ‘zero waste economy’ places increased pressure on waste producers and the UK’s £9bn waste management industry. Ian Rippin discusses the regulatory drivers and how laboratory analysis can help keep materials out of landfill As a hot topic for the coalition government, waste management is now an issue which affects many stakeholders, including ourselves as consumers. With the majority of local councils now only collecting fortnightly, many households have had to review and adapt the way that they manage their waste.

The recent unveiling of the government’s Waste Review explains the policies and a series of actions designed to support the aspiration of a 'zero waste economy'. Caroline Spelman, environment secretary – who requested the review shortly after coming to office – shared the review recommendations in her keynote speech to the Chartered Institution of Waste Management (CIWM) annual conference, held in June this year. The message was clear; waste prevention is best and if not preventable, then reuse, recycle and recover – throw away only as a last resort. The old saying, ‘waste not, want not’ still appears to hold true.

Businesses in the UK now recycle more of their waste than ever before. In England, recycling accounts for 50% of the waste produced, however the volume of waste produced still tops 45 million tonnes every year. The government and a persuasive green lobby still claim that far too much of what is left after reuse and recycling still ends up in the country’s landfill sites.

The latest Waste Review centres specifically on commercial and household waste, highlighting the need to improve the UK’s recycling capabilities, waste-to-energy technologies and to further restrict the illegal exports of waste materials. The illegal trade in waste exports recently came under scrutiny in the BBC’s Panorama exposé entitled Track my Trash. Broadcast in May, the programme revealed how many of the UK’s broken and untested electrical items find their way to toxic dumps in countries in West Africa.

“The waste hierarchy should reduce the amount of waste in its early stages, to reach the government’s ultimate target of eventually not sending any waste to landfill. However, any future landfill bans are likely to be extremely problematic to regulate”

Although still in the early stages, the government’s plans to steer the UK closer to a ‘zero waste economy’, have been broadly met with disappointment from business leaders and the waste management industry. For many, the review is a missed opportunity, as it simply re-states many of the plans already in place at the start of the process a year ago. The Waste Framework Directive, the primary European legislation for the management of waste, was revised earlier this year and was imposed as law at the end of March. If you are responsible for producing, storing, transporting, recycling, recovering or disposing of waste, then the Directive is likely to apply to you.

The revised Directive places greater emphasis on what is referred to as the ‘waste hierarchy’.  From the end of September 2011, six months after the revised Directive, anyone attempting to manage waste will need to acknowledge the waste hierarchy by declaring compliance on transfer and hazardous waste consignment notices. This enforcement of the Directive aims to ensure that waste is dealt with in a priority order: (1) prevention, (2) preparing for re-use, (3) recycling, (4) other recovery – for example, as a material for energy generation – and finally (5) waste disposal.

Further changes have been planned for the controls of what is classified as ‘hazardous waste’. Hazardous waste refers to types of waste that are harmful to human health, or to the environment, either immediately or over an extended period of time. In addition to this, changes to the specification of certain scrap metals will see some ceasing to be classified as waste at all, as long as they meet the required standards. The Waste Review explains how the use of the waste hierarchy should reduce the amount of waste in its early stages, to reach the government’s ultimate target of eventually not sending any waste to landfill. However, any future landfill bans are likely to be extremely problematic to regulate, as many believe that the steady increases in landfill tax have already created a large enough disincentive. Introduced in 1996, landfill tax was the UK's first environmental tax with a standard rate of £7 per tonne of waste, since then the levy has reached £56 per tonne. Under the coalition government’s emergency budget, landfill tax is set to increase further by a minimum of £8 per tonne each year until 2014; by which time landfill tax is expected to have soared to £80 per tonne.

A lower rate of £2.50 per tonne applies to less polluting wastes described as ‘inert wastes’. This category of waste includes materials such as rocks, clean soils, ceramics and concrete.

With two categories of waste that carry two vastly different tax levies, waste operators are extremely keen to avoid landfill disposal altogether, and only use landfill as a cost effective option for ‘so-called’ inert waste.

Wastes must be tested by the waste producer to classify them as either hazardous, non hazardous or inert, and to decide whether it is suitable for landfill in line with the Waste Acceptance Criteria (WAC).

“Waste prevention is best and if not preventable, then reuse, recycle and recover – throw away only as a last resort”

Certain types of inert waste can be accepted at landfills without the need for testing; however waste suspected of being contaminated must be proven as acceptable for landfill by its producers.

In 2005 stricter controls were applied to the waste disposal process, following a revision of both the Hazardous Waste and Landfill Regulations. The new regulations, which have been relatively effective, include the requirement for the WAC to be applied to the different landfill types and the expulsion of certain wastes from all landfills. Banned wastes include liquids, waste that is infectious from a medical or veterinary source, whole or shredded used tyres and hot or chemically active waste. Under the new guidelines, these types of waste must be recovered, recycled or alternatively disposed of, e.g. through incineration.

Hazardous wastes that fail the WAC are also prohibited from being deposited at landfill. If a waste cannot be treated, they can be sent to landfill after stabilisation by turning them into a monolith – a single uniform block. Monolithic wastes are subject to a different set of WAC to the majority of wastes, classed as ‘granular’.

Standard laboratory based WAC testing provides a level playing field for the waste industry – helping prevent unsuitable, dangerous or polluting waste from being deposited in the wrong class of landfill.

WAC is primarily a compliance test – pass or fail – against regulatory limit values. There are three sets of WAC for inert, hazardous and non-reactive hazardous waste, each with a different limit value for the required parameters. These tests largely consist of numerical limits for leachable substances and organic content, with limit values for some key contaminants.

The leaching test specified for use in waste acceptance testing is prescribed within the landfill directive to provide comparable and consistent results between laboratories. The test used is the BS EN 12457 1, or 2 stage leaching test at a liquid to solid ratio of 10:1. This leaching test consists of the preparation of an eluate for analysis by agitating a pre-weighed sample of specified particle size in water for a total of 24 hours. The eluate is then extracted by filtration at 0.45um.

The main elements of concern for WAC testing are Antimony (Sb), Arsenic (As), Barium (Ba), Cadmium (Cd), Chromium (Cr), Copper (Cu), Lead (Pb), Mercury (Hg), Molybdenum (Mo), Nickel (Ni), Selenium (Se) and Zinc (Zn). These parameters are analysed in the eluate by Inductively Coupled Plasma Mass Spectrometry (ICPMS), or an equivalent technique.

The test for organic content involves total combustion in oxygen in a specialist analytical instrument and is a particularly important analyte as key limit values are placed on it to meet a definition of an ‘inert’ waste, or to prevent potentially reactive wastes from entering hazardous landfills. Often the types of waste being analysed can present specific analytical problems that make an accurate diagnosis difficult to achieve. It is essential that a laboratory undertaking WAC testing has the sufficient expertise and experience to overcome these issues.

The costs involved in sending a large consignment of waste to a higher class of landfill than necessary can be extremely large. On the other hand, there are severe penalties for depositing a consignment of waste at the wrong class of landfill, making it imperative to use an efficient testing service. Contact:

t: 0113 231 2177

w: www.natlabs.co.uk Author:

Ian Rippin, commercial director of the National Laboratory Service (NLS)