Growing use for sludge

Many years of research show that using biosolids should be a highly attractive environmental option - yet doubts persist, writes Barrie Clark

Has demand for thematic picture calendars passed its peak? Obviously the National Trust and Robbie Williams will go on forever, along with babes and beefcake (caps off in 2006 Freddy Flintoff).

The market must be declining though: how else to explain why The Biosolids Year failed to appear? It’s a pity really because 2006 promises real progress in overcoming doubts about the use of treated sewage sludge in agriculture.

The positive case is strong on grounds of sustainability. Research over many years has shown that recycling sludge as a soil improver and fertiliser is the best practicable environmental option. It is supported by Government and regulators over alternatives like landfill and incineration and 62% of the annual 1.3M tonnes dry solids produced by wastewater companies are used in this way (see chart below).

The companies have invested heavily in the treatment process and agreed a Safe Sludge Matrix with stakeholders, including food retailers. No adverse effect on human health has ever been identified resulting from use of biosolids according to the matrix.

Yet doubts persist and are undermining this sustainable practice by gradually

reducing the area of land where biosolids are used. Let us accept that such doubts

are understandable.

The main problems are the human experience we know as faecal aversion and the perception that, whatever the science says, any association could be presented by suppliers of alternative products or the media as a threat to health. There are no magic wands to wave away such fears. What we need is continued, honest and painstaking communication and a regulatory framework built on sustainability. How will things move forward in 2006?

First, government is likely to consult on and pass revised sludge regulations. The amendments will introduce microbiological limits for the final product, formalise record keeping and improve quality control procedures. They will incorporate the current voluntary use of the Safe Sludge Matrix. Ministers began working towards the new regulations in 2002, and since then companies have been meeting the new requirements. However formal regulation is a very important reassurance because it makes compliance audits a statutory requirement.

Second, along with the revised regulations the Code of Practice for Agricultural Use of Sewage Sludge will be updated and strengthened. It is expected that new good practice measures will be included together with hazard analysis critical control point (HACCP) procedures familiar to food and drink companies. The industry published a HACCP Guide for biosolids recycling in 2003 and the new code should underpin existing methods and build confidence.

Third, the European Commission has indicated its aspiration that over 75% of sewage sludge produced in member states should be made suitable (that is treated) for recycling to land in 20 years. The UK is arguably ahead of legislation, particularly with regard to microbiological safety through the matrix and the updated regulations. It now appears that the primary directive (86/278/EEC) will also be revised in 2006 to include in quality standards a reduction in permitted levels of certain metals. It is likely that the EC will emulate the good practice demonstrated by the UK and introduce formal, specific pathogen standards and controls.

Reforms begin to bite

Fourth, reforms to EU agriculture policy will begin to bite. Since January 2005, CAP payments to farmers have depended on “cross compliance” – the achievement of baseline standards for environmental and public health. Farmers must ensure that nutrient application rates are consistent with crop need and environmental legislation and any transgression could mean lower payments. But the policy makes the sludge-in-agriculture regulations a statutory management requirement. So, with UK practice being more stringent than the EU, those who use biosolids in accordance with UK standards automatically meet the demands of cross-compliance.

Finally, the water industry and stakeholders will combine to build an even more substantial case. Next month a new improved Water UK Biosolids Briefing Pack will be published. Everything you need to know – the law, the science, the investment and the A-list supporters – will be available on line and in print. In the spring a new industry pamphlet on wastewater treatment highlights the natural role of recycling in managing one of society’s most basic needs.

Supportive initiatives from Green Alliance and Forum for the Future are being planned for later in the year. We can’t guarantee that sludge cake will rival beefcake (sorry), but a good year for sustainability is in prospect.

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