Where there’s muck, there’s brass – but after fifty years of value, is it time for a rethink? Dr Peter Matthews, Past President of CIWEM and former Chair of Natural Resources Wales, reflects on half a century of generating value from waste and asks if policy and priority are really aligned in the biosolids debate.
There was a time when sewage – urban waste water – was simply a problem to be got rid of as fast as practicably possible. But it wasn’t long before some bright spark discovered what had been thought of as waste was anything but. Ever since, we’ve been in a race to extract value from it – for energy, for fertiliser, even for the water it contains. But as the Environment Agency looks again at biosolids policy, are we learning all the lessons of the past that we can?
Fundamentally, sewage is a sustainable resource. For a long time, it and the products of engineered treatment – what we’ve come to call sludge – have been treated and used beneficially on land. There are still memories of the ‘honey cart’ of ‘septage’ in many places in the countryside. And in recent times, almost all the sludge produced by sewage treatment in England and Wales has been used safely and beneficially on agricultural land.
Thus was created the concept of ‘biosolids’: in simple terms, treated sewage sludge used in agriculture in accordance with national regulations and agricultural best practice. Biosolids to land is an excellent example of how a happy alliance of economics and sustainability can work. Biosolids that go to land avert the need for the natural alternatives of carbon intensive incineration, and a reliance on artificial fertilisers.
That said, our senses combined with society’s (quite legitimate) focus on public health occasionally replenish our angst about anything to do with sewage. Concerns such as microplastics, anti-microbial resistance and ‘forever chemicals’ bubble up. And while management practices have evolved to reflect community concerns, fifty years have passed since our current control systems started to form back in 1971. The Biosolids Assurance Scheme, led by the water industry, is one of the most recent moves taken to demonstrate that careful practice can provides the assurance that farmers, regulators and food manufacturers crave.
The birth – and death? – of a national strategy
Our first National Strategy considering all aspects of sludge management was established in 1981 after the formation of a national approach to the delivery of water services in 1974. The next big step in agricultural use was the Sludge (Use in Agriculture) Regulations, and associated Code of Practice in 1989 (supplemented in 1992 by the Safe Sludge Matrix). But since then, there has been a gradual disintegration of the National Strategy, as other sludge management routes became subject to different regulatory regimes.
The Environment Agency has now proposed a fundamental change in sludge regulation. And whilst it is called a Sludge Strategy, it focuses just on biosolids to land. It proposes to bring this into the Environmental Permitting Regulations (EPR) regime, but leaves other aspects of sludge management already within the EPR separate and fragmented. There is not, per se, a National Strategy or regulatory framework.
The EA is right that it is time for a review and refresh – inevitably, incremental change over decades has resulted in inconsistencies which need resolving. But what is proposed departs from what we know works, building on the last fifty years of sludge management. What’s more, it falls short of ‘better regulation’ principles, and abandons the principles of integration. I don’t believe it has to be that way, and there’s no better time than now to rethink the approach.’ Click here to read more