The Air Quality Standards Regulations 2007

Regulation 31

SCHEDULE 12 Collation of information and criteria for aggregating data and calculating statistical parameters

PART 1 Information to be submitted to the Commission

1.  The following information on ozone concentrations shall be obtained and collated—

	Type of station	Level	Averaging/accumulation time	Provisional data for each month from April to September	Report for each year
(1) Maximum daily 8-hour mean.
(2) In this table, “AOT40” has the same meaning as in paragraph 2(d) of Part 4 of Schedule 1.
Information threshold	Any	180μg/m3	1 hour	For each day with any exceedance: date, total hours of, exceedance, maximum 1 hour ozone and related NO2 values when required;	For each day with any exceedance: date, total hours of exceedance, maximum 1 hour ozone and related NO2 values, when required
				monthly 1 hour maximum ozone
Alert threshold	Any	240μg/m3	1 hour	For each day with any exceedance: date, total hours of exceedance, maximum 1 hour ozone and related NO2 values, when required	For each day with any exceedance: date, total hours of exceedance, maximum 1 hour ozone and related NO2 values, when required
Health protection	Any	120μg/m3	8 hours	For each day with any exceedance: date, 8 hours maximum(1)	For each day with any exceedance: date, 8 hours maximum(1)
Vegetation protection	Suburban, rural, rural background	AOT40(2) = 6,000 μg/m3.h	1 hour, accumulated from May to June		Value
Forest protection	Suburban, rural, rural background	AOT40(2) = 20,000μg/m3.h	1 hour, accumulated from April to September		Value
Materials	Any	40 μg/m3	1 year		Value

2.  The Secretary of State shall also ensure that the following information is collated—

(a) for ozone, nitrogen dioxide, oxides of nitrogen and the sums of ozone and nitrogen dioxide (added as parts per billion and expressed in μg/m³ ozone) the maximum, 99.9th, 98th and 50th percentiles and annual average and number of valid data from hourly series; and

(b) the maximum, 98th and 50th percentile and annual average from a series of daily 8-hour ozone maxima.

3.  Data compiled in monthly reports shall be considered provisional and shall be updated where necessary in subsequent submissions.

PART 2 Criteria for aggregating data and calculating statistical parameters

4.  In this Part, percentiles are to be calculated using the method specified in Council Decision 97/101/EC(1) establishing a reciprocal exchange of information and data from networks and individual stations measuring ambient air pollution within member States.

5.  The following criteria are to be used for checking validity when aggregating data and calculating statistical parameters—

Parameter	Required proportion of valid data
(1) In this table, “AOT40”has the same meaning as in paragraph 2(d) of Part 4 of Schedule 1.
(2) In cases where all possible measured data are not available, the following factor shall be used to calculate AOT40 values: AOT40 (estimate) = AOT40 measured x (total possible number of hours ÷ number of measured hourly values). The reference in this formula to the total possible number of hours is to the hours within the time period of AOT40 definition (that is, 8:00 to 20:00 Central European Time from 1 May to 31 July each year, for vegetation protection and from 1 April to 30 September each year for forest protection).
1 hour values	75% (45 minutes)
8 hour values	75% of values (6 hours)
Maximum daily 8 hours mean from hourly running 8 hours averages	75% of the hourly running 8 hour averages (18 8 hours averages per day)
AOT40(1)	90% of the 1 hour values over the time period defined for calculating the AOT40 value(2)
Annual mean	75% of the 1 hour values over summer (April to September) and winter (January to March, October to December) seasons separately
Number of exceedances and maximum values per month	90% of the daily maximum 8 hours mean value (27 available daily values per month) 90% of the 1 hour values between 8:00 and 20:00 Central European Time
Number of exceedances and maximum values per year	Five out of six summer months over the summer season (April to September)

(1)

OJ L 35, 05.02.97, p.14.