Small-Group Activity: NAAQS Exercise Nate Herbst Southern Ute Indian Tribe

2 NAAQS Introduction What is the NAAQS? Why is the NAAQS important? How is compliance with the NAAQS determined?

3 What is the NAAQS? National Ambient Air Quality Standard Each criteria pollutant has a designated NAAQS NAAQS for ozone is 4 th maximum 8-hr rolling average of 0.084ppm –Also hourly NAAQS of 0.124ppm Fourth highest 8-hr average for a year can’t surpass 0.084ppm Unless otherwise noted, data used in this presentation are in ppm

4 Calculating 1-hr Averages 1-hr NAAQS is 0.124ppm –For any 1-hr period, average shouldn’t surpass 0.124ppm 1-hr NAAQS fazed out 5 years ago Still used in ~100 counties nationwide Main NAAQS for ozone is 8-hr rolling average

5 Calculating 8-hr Averages 8-hr rolling average is average of 8 consecutive 1-hr averages 8-hr avg. for 7am is average of 12:00am – 7:00am; 8-hr avg. for 8am is average of 1:00am – 8:00am. Data are in ppb

6 The Fourth Max 8-hr rolling averages automatically calculated with different DAS software AQS calculates 8-hr averages directly from 1-hr averages At end of a year, AQS will find 4th highest 8-hr average 4 th highest 8-hr average is designated “4 th max” This value should be less than or equal to 0.084ppm

7 June 2002 Ozone 1-hr Avgs. Data are in ppb

8 June 2002 Ozone 8-hr Avgs. Data are in ppb

9 The Design Value Design value used to determine classification Design value is average of 3 consecutive annual 8-hr 4 th max averages Example 8hr 4 th max ppm ppm ppm Average 0.068ppm Average of 3 consecutive annual 4 th max 8-hr averages is design value for that data set

10 Attainment? Area can be classified as 1 attainment, 2 non-attainment or 3 unclassifiable Attainment areas have design values ≤ 0.084ppm Non-attainment areas have design values > 0.084ppm Unclassifiable areas can’t be classified –Insufficient data –Insufficient or failing QA/QC data –Good data which haven’t been submitted

11 Exercise 1 Calculate 8-hr Rolling Avgs.

12 Exercise 2 Determine 4 th Max 8-hr Avg. Data are in ppb

13 Exercise 3 Determine Design Values 4 th max What are the design values for: In Attainment?

14 Summary Ozone NAAQS is annual 4 th max 8-hr rolling average ≤ 0.084ppm. Design value is 3-year average of 4 th max 8- hr averages Design value determines whether an area is in attainment, non-attainment, or is unclassifiable You now know how to make all these computations and understand about all there is to know about the ozone NAAQS