PART 2Group A and Group B pollutants and ozone
CHAPTER 4Assessment
Sampling points15.
(1)
Where the Secretary of State assesses concentrations of a Group A or Group B pollutant by fixed measurement he shall, except in cases falling within paragraph (2)(a), install the number of sampling points required for the zone in accordance with the relevant Part of Schedule 5.
(2)
Where the Secretary of State assesses concentrations of a Group A or Group B pollutant by—
(a)
fixed measurement, in cases where he obtains information from modelling techniques under regulation 14(2); or
(b)
combined measurement,
he shall install the number of sampling points he determines is sufficient, taken together with the spatial resolution of the other techniques employed, for concentrations of the relevant pollutant to be established within the zone concerned.
(3)
The Secretary of State shall locate all sampling points for Group A and Group B pollutants in accordance with the requirements set out in the relevant Parts of Schedule 6.
(4)
Where the Secretary of State assesses concentrations of ozone by fixed measurement he shall, except where paragraphs (5) or (6) apply, install the number of sampling points required for the zone in accordance with Part 4 of Schedule 5.
(5)
In the case of zones where—
(a)
five years of measurement have been carried out; and
(b)
during each of those years, concentrations of ozone have been below the long-term objectives,
the Secretary of State may determine the number of sampling points in accordance with Part 5 of Schedule 5.
(6)
In the case of zones in which the Secretary of State supplements the information obtained from sampling points for fixed measurement with information from modelling techniques or indicative measurement in accordance with regulation 14(3)(b), he may reduce the number of sampling points for ozone provided that—
(a)
he considers that the modelling techniques adopted provide an adequate level of information for the assessment of air quality with regard to—
(i)
the target values;
(ii)
the information threshold; and
(iii)
the alert threshold;
(b)
he considers that the number of sampling points to be installed and the spatial resolution of other techniques are sufficient for the concentration of ozone to be established and to enable the compilation of assessment results as specified in Part 3 of Schedule 7;
(c)
the number of sampling points in each zone amounts to—
(i)
at least one sampling point per two million inhabitants; or
(ii)
one sampling point per 50,000 km²,
whichever produces the greater number of sampling points;
(d)
each zone contains at least one sampling point; and
(e)
concentrations of nitrogen dioxide are assessed at all remaining sampling points except rural background stations.
(7)
The Secretary of State shall ensure that—
(a)
except where paragraph (6)(e) applies, concentrations of nitrogen dioxide are assessed at least half of the number of sampling points required to be installed for ozone in accordance with Part 4 of Schedule 5; and
(b)
the measurement of nitrogen dioxide taken at any sampling point is continuous, except at rural background stations where other measurement methods may be used.
(8)
The Secretary of State shall locate all sampling points for ozone in accordance with the requirements set out in the relevant Parts of Schedule 6.