Sewage sludge, also known as biosolids, has been recycled to
agricultural land for many decades throughout Europe. This is the
Best Practicable Environment Option (BPEO) in most circumstances,
adding plant nutrients and humus-forming material to enrich the
soil, and is supported by the UK government, and European
Commission. In the UK over 1 million tonnes dry solids) of sludge
is produced every year of which 55% is recycled to agricultural
land. This represents about 2% of the total quantity of organic
material being applied to land with 94% being animal manure and
slurry, and the remaining 4% other industrial waste.
Top of page
Recycling sludge is a regulated process. Current controls are
based on a 1986 EU Directive (Sludge Directive 86/278/EEC) which
was implemented in the UK in 1989 through the Sludge (Use in
Agriculture) Regulations.
The regulations are supported by a Code of Practise which
details all aspects of sludge recycling to land, setting
application rates, information requirements and guidelines for best
practise. Revisions to the regulations are expected to come in
force in 2002 and will be introduced by the Department for
Environment, Food and Rural Affairs (DEFRA) for England and the
Scottish Executive and National Assembly for Wales for the devolved
administration. These amendments will introduce microbiological
limits for the final sludge product, formalise the record keeping
and introduce critical control point procedures to ensure improved
quality control. The relevant environment agency will maintain its
statutory duty to undertake audits of compliance with process
standards and will continue to audit recycling operations.
Top of page
A voluntary agreement, the “Safe Sludge Matrix” has been in
place throughout the UK since 1999. The agreement, made between
Water UK and sewage operators and the British Retail
Consortium (BRC), anticipates the revision to the Sludge (use in
Agriculture) regulations 1989 and has influenced the ongoing
revision of the EU Sludge Directive.
The Safe Sludge Matrix included inputs from the Environment
agencies, DEFRA and the Foods Standards Agency (FSA) with intensive
consultation with other stakeholders such as the National Farmers
Union (NFU), Country Land and Business Association (CLA), food
manufacturers and processors.
The Matrix requires strict controls on the quality of sludge and
the correct procedures to be adopted for its application to
agricultural land used to grow food crops. In addition the use of
untreated sludge on land growing crops phased out in December
1999. The water industry has made a substantial investment to meet
the objectives of the matrix and the controls are being applied
ahead of the requirements of the revised regulations. The matrix
provides robust safeguards for all stakeholders-farmers, food
retailers and processors and consumers.
Top of page
There has been extensive and continuing research into the use of
sludge on agricultural land over the last forty years. In
particular considerable additional research has been conducted in
order to underpin the provisions of the Safe Sludge Matrix and the
proposed standards in the revised Regulations.
The work confirms that any risk to the food chain or the
environment from recycling treated sludge to land is exceedingly
small provided it is carried out in accordance with the
Regulations, the Code of Practise and the Safe Sludge Matrix. In
addition there has been no instance in the UK in which a link has
been established between the controlled application of sewage
sludge and the occurrence of disease in the general population
through food or water contamination. All research reports are in
the public domain and can be examined if required. The results from
on-going research will also be published.
Top of page
Recycling biosolids to land is a controlled and well regulated
process and provided the controls are followed presents minimum
risk to humans, animals and the environment. The recent
developments in the Safe Sludge Matrix and the proposed new
Regulations provide additional safeguards for a process that has
been strictly controlled in the UK 1989. Recycling biosolids to
land is a sustainable option, utilising its beneficial properties
by providing nutrients and organic matter for soil and plants. It
is supported by the Government at national and European Level.
The development of the new Regulations and Safe Sludge Matrix
involves a wide range of organisations representing different
stakeholders to provide everyone with the reassurance that
recycling biosolids to land in line with controls does not place
public health at risk.
The Organisations listed below have contributed to the content
of this briefing note:
- ADAS
- British Rail Consortium
- Country Land and Business Association
- Department for Environment Food and Rural Affairs
- Environment Agency
- Foods Standards Agency
- Forum for the Future
- National Farmers Union
- Scottish Environment Protection Agency
- Scottish Executive
- The Natural Step
- Water UK
Top of page
