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SCHEDULE 5 continued PART 4
7. The minimum number of sampling points for fixed measurement of ozone to assess compliance with the target values, long-term objectives and information and alert thresholds where continuous measurement is the sole source of information is set out in the following table—
(1)
At least 1 station in suburban areas, where the highest exposure of the population is likely to occur. In agglomerations at least 50% of the stations shall be located in suburban areas. |
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(2)
1 station per 25,000 km² for complex terrain is recommended by Directive 2002/3/EC. |
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| Population of zone (thousands) | Agglomerations (urban and suburban)(1) | Other zones (suburban and rural)(1) | Rural background |
|---|---|---|---|
| 0–249 | 1 | 1 | 1 station/50,000 km² as an average density over all zones in England(2) |
| 250–499 | 1 | 2 | |
| 500–999 | 2 | 2 | |
| 1,000–1,499 | 3 | 3 | |
| 1,500–1,999 | 3 | 4 | |
| 2,000–2,749 | 4 | 5 | |
| 2,750–3,749 | 5 | 6 | |
| 3,750 or more | 1 additional station per 2 million inhabitants | 1 additional station per 2 million inhabitants | |
8. In cases where zones attain the long-term objectives, the number of sampling points for ozone shall, in combination with other means of supplementary assessment such as air quality modelling and co-located nitrogen dioxide measurements, be sufficient to examine the trend of ozone pollution and check compliance with the long-term objectives.
9. The number of stations located in agglomerations and other zones may be reduced to one-third of the number specified in the Table in Part 4. Where information from fixed measurement stations is the sole source of information, at least one monitoring station shall be kept. If, in zones where there is supplementary assessment, the result of this is that a zone has no remaining station, adequate assessment of concentrations of ozone against long-term objectives shall be ensured through co-ordination with the number of stations in neighbouring zones.
10. The number of rural background stations shall be 1 per 100,000 km².
Regulation 15(3) and (8)Regulation 19(2)(b)Regulation 20(3)(b)
1. Sampling points directed at the protection of human health shall be sited to provide data on—
(a) the areas within zones where the highest concentrations occur to which the population is likely to be directly or indirectly exposed for a period which is significant in relation to the averaging period of the relevant limit value; and
(b) concentrations in other areas within the zones which are representative of the exposure of the general population.
2. Sampling points shall in general be sited to avoid measuring very small micro-environments in their immediate vicinity. Where possible, the Secretary of State shall locate sampling points so as to be representative of air quality in a surrounding area of no less than 200 m² at traffic-orientated sites and of several square kilometres at urban-background sites.
3. Sampling points shall also, where possible, be representative of similar locations not in their immediate vicinity.
4. Account shall be taken of the need to locate sampling points on islands, where that is necessary for the protection of human health.
5. Sampling points targeted at the protection of ecosystems or vegetation shall be sited more than 20 km from agglomerations or more than 5 km from other built-up areas, industrial installations or motorways. Where possible, the Secretary of State shall locate sampling points so as to be representative of air quality in a surrounding area of at least 1000 km². A sampling point may be sited at a lesser distance or to be representative of air quality in a less extended area, taking account of geographical conditions. Account shall be taken of the need to locate sampling points on islands.
The Air Quality Standards Regulations 2007