The DoE's figures are based on quarterly returns from local authorities. Early returns, as well as a joint survey conducted by the National Society for Clean Air and the Association of Metropolitan Authorities, indicated either that the DoE had seriously overestimated the number of processes which would be caught by the new controls, or that many operators had not submitted applications by the due date, or both.
When the legislation was introduced, the DoE estimated that it would apply to some 27,000 processes, of which about 12,000 were small waste oil burners. Operators were due to apply for authorisations in three blocks ending on 30 September 1991, 31 March 1992, and 30 September 1992.
At the very least, more than 11,000 applications were expected in the first two blocks. However, the AMA/NSCA survey revealed that only just over 6,000 applications for processes in these blocks had been received by last May (ENDS Report 209, p 7 ).
The DoE's figures for the 12 months ending 31 March 1992 broadly confirm this picture. The results include some extrapolation for the last quarter, when only 336 (75%) councils sent in returns, in contrast to the 98% response rate for the three earlier quarters.
The figures show that a total of 6,312 applications for authorisation were received in the first 12 months of the new control system. More than half were made in the last quarter (see table ).
Under the 1990 Act, applications are to be determined within 12 months of submission except in the case of small waste oil burners, for which the determination period is four months. A total of 1,356 authorisations - equivalent to 21% of all applications - had been issued by 31 March 1992. Since only 545 of these were for waste oil burners, a large number of applications are apparently being determined well within 12 months.
However, the performance of different kinds of local authority in determining applications varies markedly. The proportion of applications determined by 31 March 1992 varied from 0% among port health authorities to 34% among London boroughs (see table ).
This variation can in part be explained by the profile of industrial processes in different areas, and by the extent to which authorities have actively looked for processes for which operators had failed to submit applications. One or both of these factors may explain why 84 of the 91 applications submitted to port health authorities were received in the last quarter.
However, when the pattern of applications across the four quarters is taken into account, Welsh districts and metropolitan boroughs appear to be determining applications at a significantly slower pace than London boroughs and English districts.