When used correctly it does reduce the problem of odour from wet slurries. However, the spreading of dry sewage cake is not without its problems. The Chartered Institute of Environmental Health Annual Report statistics indicates a steep rise in complaints since 1992. Preliminary figures for the report to be published in September of this year indicate that the trend is continuing to rise at a similar rate. With the further increase of sewage sludge disposal to land post 1998, these figures are set to continue to rise over the next seven years unless consistent attention is paid to controlling odours from the material.
Odour is of course difficult to assess and measure.
Despite the difficulties in measurement no one likes a bad smell and subconsciously it is still linked back to the miasma theories of the last century and that bad smells in some way are associated with the spread of diseases. The Chartered Institute and local authorities accept the need to look at more sustainable and acceptable ways of disposal of sewage sludge. However, it should be borne in mind that local authorities have a statutory duty to investigate complaints of matters which may be prejudicial to health or nuisance. In the case of a nuisance arising from a business premises, the maximum penalty is 20,000 under the Environmental Protection Act 1990. In concluding I have raised a number of points of concern about the acceptability of disposal of sludge to agricultural land.