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

Regulation 31

PART 1Information 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

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

(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.

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 2Criteria 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/EC21 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 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)

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).