The study was carried out for the DoE by the Building Research Establishment (BRE) in response to a recommendation by the official Noise Review Working Party in 1990 (ENDS Report 189, pp 31-32). It was completed last year, but the DoE has persistently refused to make it public. However, the findings have been summarised in a conference paper presented by its author, Colin Grimwood of BRE.
Powers for local authorities to designate NAZs were created by the Control of Pollution Act 1974 and brought into force in 1976. NAZs were designed to supplement their established powers to act against noise under nuisance legislation, which cannot deal with excessive noise caused by a multiplicity of sources or by small increments in noise over time. They were intended to deal with industrial and commercial noise in particular.
In designating an NAZ, a local authority must specify the classes of premises to which it relates. It must then measure noise emissions from all classified premises, and enter the results in a noise level register. The registered levels must not be exceeded without the authority's consent. In addition to this "standstill" provision, the Act empowers local authorities to serve a noise reduction notice on any premises, where a reduction in noise emissions is "practicable at reasonable cost and would afford a public benefit."
The main findings of BRE's survey were as follows:
The study concludes that NAZs have proved unpopular, and won a bad reputation because the large zones initially designated could not be operated at a reasonable cost. Local councils generally claimed that the setting-up and monitoring costs were disproportionate to the benefits to local communities.
Some authorities were also found to have used their powers in such a way as to encourage increases in noise levels within NAZs. For example, some measured noise levels at times of peak emissions and entered these in their registers. Others concerned about the cost of noise surveys allowed businesses to determine their own noise emissions. And a few have rubber-stamped applications to exceed registered noise levels provided that no complaints were likely, regardless of any increase in ambient noise.
However, NAZs have proved successful where they were intended to prevent excessive noise from a small number of premises.
Three years ago, the Noise Review Working Party also found that NAZs were proving difficult to operate. Its report recommended that they should be revived by giving local authorities greater flexibility to devise their own procedures under a framework code of practice rather than being bound by statute. However, the BRE study concludes that the complexity of NAZ procedures is not the only problem, and that a more fundamental reappraisal of the value of NAZs is in order.
The DoE promised in response to the 1990 report that it would "aim to devise simpler and more practical procedures" for NAZs. It has been sitting on BRE's report for many months, and a claim in a parliamentary answer in October by Environment Minister Tim Yeo that it is "considering the effectiveness" of NAZs suggests more activity than appears to be the case.
The Minister's answer offers little prospect of new policy developments. In reaching conclusions on the BRE study, he said, "we must balance the need to limit the regulatory burden on business with the continuing need to deal effectively with noise pollution."
Meanwhile, it should be recalled that NAZs were a response to the upward trend in public complaints about noise from industrial and commercial premises. In 1974, the complaint rate was 312 per million people. It has been on an unbroken upward trend ever since, and reached a record 1,054 per million in 1991/2.