1 Technical Support Document for 2008 Ozone NAAQS Designation for Puerto Rico



### Puerto Rico Area Designations f or the

20 08 Ozone National Ambient Air Quality Standard s

No areas of Puerto Rico violate the 2008 National Ambient Air Quality Standards for 2008 ozone NAAQS. Two monitors constitute the EPA

- approved ozone network in Puerto Rico and both have design values well under the 0.075ppm NAAQS.

Technical Analysis for Puerto Rico

Since the air quality from the EPA

- approved network is attainment at all the sites in Puerto Rico, the only factors to review are 1) the air quality data and 2) whether Puerto Rico impacts any nonattainment

areas.

In a February 4, 2009 letter to the USEPA, Puerto Rico recommended that all of Puerto Rico be designated as attain ment for the 2008 ozone NAAQS b ased on air quality data from 2006

- 2008. These

data are from Federal Reference Method ( FRM ) monitors sited and operated in accordance with 40 CFR

Part 58

.

No comments or additional correspondence from Puerto Rico were rec eived after EPA proposed these designations.

After considering Puerto Rico’s recommendation and b ased on EPA's technical analysis described below, EPA will designate all of Puerto Rico as attainment/unclassified for the 20 08 o zone NAAQS

.

Factor Assess ment



### Factor A : Air Q uality D ata

For this factor , we considered 8

- hour o zone design values (in ppm ) for air quality monitors in Puerto

Rico based on data for the 2008

- 2010 period (i.e., the 2010 design value, or DV) , which are the most

recent years with fully

- certified air quality data

. A monitor’s DV is the metric or statistic that indicates whether that monitor attains a specified air quality standard. The 2008 o zone NAAQS are met when the

annual f ourth

- highest daily maximum 8

- hour average concentrat ion, averaged over 3 years is 0.075 ppm or less

. A DV is only valid if minimum data completeness criteria are met. See 40 CFR part 50 App endix P . Where several monitors are located in a county (or a designated nonattainment area or maintenance area ), th e DV for the county or area is determined by the monitor with the highest level.

The 2010 DVs for the o zone NAAQS for counties in Puerto Rico a re shown in Table 2

.

Table 2 . Air Quality Data

. Location 2008

- 2010 Design Value (ppb)

Catano 40

Juncos 402 Data for these two sites meet EPA’s completeness requirements and are well under the 75ppb ozone NAAQS. See the attached report from EPA’s Air Quality System for the data used for this table.

PR-VI O3.pdf



### Factor B : Impact on othe r areas

As part of EPA’s evaluation of Section 110 ozone transport State Implementation Plans, EPA determined that Puerto Rico is too far from any other nonattainment areas to cause to contribute to violations of the ozone NAAQS in these areas. The neare st nonattainment areas are in the eastern portion of the continental United States, over a thousand m iles from San Juan, Puerto Rico.

PR_110(a)(2)(D)(i) letter_Nov 29.pdf



### Conclusion

Based on the assessment of factor s described above EPA concludes that Puer to Rico has met the CAA

criteria for attainment of the 2008 ozone NAAQS, as all monitors in its EPA

- approved ozone network show attainment of the ozone standard. In addition, Puerto Rico is far enough from other ozone

nonattainment areas that is does not cause or contribute to any nonattainment for the 2008 ozone NAAQS.