9.—(1) The Department shall assess the levels of ozone in ambient air in all zones.
(2) The Department shall ensure that fixed measurements are taken in any zone where the concentrations of ozone have exceeded the long-term objectives specified in Schedule 4 during any of the previous five years of measurement.
(3) Save as provided for in paragraph (4) for the purposes of paragraph (2), measurements shall be taken in accordance with the reference measurement methods specified in point 8 of Section A of Annex VI to the Directive.
(4) Alternative methods to those referred to in paragraph (3) may be used provided the conditions set out in Section B of that Annex are complied with.
10.—(1) The Department shall install sampling points in accordance with the criteria set out in Annex VIII to the Directive.
(2) In zones where fixed measurement is the sole source of information for the assessment of air quality, the number of sampling points shall be more than or equal to the minimum number specified in Section A of Annex IX to the Directive.
(3) In zones where the concentrations of ozone have been below the long-term objectives for each of the previous five years of measurement, the number of sampling points shall be determined in accordance with the criteria set out in Section B of Annex IX to the Directive.
(4) In zones where the information from fixed measurement is supplemented by information from modelling or indicative measurement or both, the number of sampling points referred to in paragraph (2) may be reduced provided that the following conditions are met—
(a)the supplementary methods provide sufficient information for the assessment of air quality in relation to target values, long-term objectives, information and alert thresholds;
(b)the number of sampling points to be installed and the spatial resolution of supplementary methods are sufficient for the concentration of ozone to be established in accordance with the data quality objectives set out in Section A of Annex I to the Directive and to enable assessment results to meet the criteria specified in Section B of the same Annex;
(c)there is at least one sampling point in each zone, with a minimum of one sampling point per two million inhabitants or one sampling point per 50,000 km2, whichever produces the greater number of sampling points; and
(d)nitrogen dioxide is measured at all remaining sampling points except at rural background stations referred to in Section A of Annex VIII to the Directive.
(5) The Department shall ensure that nitrogen dioxide is measured at no less than 50% of the sampling points required under Section A of Annex IX to the Directive.
(6) The measurement referred to in paragraph (5) shall be continuous except at rural background locations.
(7) The Department shall ensure that concentrations of the ozone precursor substances listed in Annex X to the Directive are measured at at least one sampling point.
(8) The Department may choose the location and number of sampling points for measurements of ozone precursor substances and shall take into account the objectives and methods set out in Annex X to the Directive.