PRO't UNITED

STATES

ENVIRONMENTAL

PROTECTION

AGENCY

RESEARCH TRIANGLE

PARK, NC 27711

November 5, 2008 OFFICE OF

AIR QUALrrY PLANNING

AND STANDARDS

MEMORANDUM

SUBJECT:

FROM: Nitrogen

Dioxide

(NO2) Descriptive

Statistics

Tables

Rhonda Thompson

••_•.

4- •

Air Quality Analysis

Gr6up (C304-0)

TO: NO2 NAAQS

Review Docket

Nitrogen Dioxide

(NO2) monitoring

data for 2004-2006

were pulled from the Air Quality

System (AQS). Alternative

NO• design values were calculated

for monitors

that were at least 75

percent complete

for hours in a day and days in a quarter and had all 4 quarters

and all 3 years.

Table shows the percent of U.S. counties

with monitors

(and percent of population

in counties

with monitors)

that did exceed alternative

NO2 standards.

The alternative

forms are the 3-year

average of either the 99 th

or 98 th percentiles

of the daily 1-hour maximum.

The alternative

levels

for either form are 0.20, 0.15, 0.10,

or 0.05. Population

is in millions

and the number of counties

is in the top

row and percentages

are in the tables.

For the 17 areas in Tables 2 and 3, the monitoring

data were aggregated

to either the

Consolidated Metropolitan

Statistical

Area (CMSA)

or, if no CMSA, the Metropolitan

Statistical

Area according

to the 1999 Office of Management

and Budget definitions

(January

28, 2002

revision). The monitoring

site within an area that had the highest 1-hour design value on a given

metric was chosen as the source of that metric value for the area. Table 2 has the 2 na through

9 th

highest and the 99 th and 98 th percentiles

of the daily maximums

for each of the areas. Table 3

shows the ratios of all of the possible

metrics (both the 99 th and 98 th percentiles

of the daily

maximum and daily average)

with each other and the current metric (annual average)

for the 17

areas. Each ratio is rounded

to the nearest hundredth.

For the alternative

daily metrics,

the

statistics were computed

for each year and then averaged

over 2004-2006;

while the form of the

current metric, the annual average,

is the maximum

of the annual averages

over 2005-2006.

Three of the 17 areas did not meet all completeness

requirements

above and, therefore,

only the

complete year data were used in the calculations.

Detroit monitors

261630016

and 0019 were complete for 2006 but only monitor

0019 was complete

for 2004 and 0016 for 2005; as such,

Intemet Address (URL) http://www.epa.gov

Recycled/Recyclable Printed with Vegetable Oil Based Inks on Recycled Paper (Minimum 25% Postconsumer)only

the 2 complete

years were included

in the averages.

The Jacksonville

monitor

was only

complete for 2006. The Provo monitor

was only complete

for 2004 and 2005.

Attachment: Tables 1-3

cc:. Phil LorangTable 1 Predicted percent of counties with monitors (andpercent of population in counties with monitors) exceeding alternative NO2standards.Number of counties with monitors (population in 1000s)AlternativeStandardsand Levels(ppm)Total counties(population inmillions)NortheastSoutheastIndustrialMidwestUpperMidwestSouthwestNorthwestSouthernCAOutsideRegions**138 (93.9)31322012920131Percent of counties, total and by region, (and totalpopulation) not likely to meet standard and level*3 year 99th percentile daily 1 hour max:0.200000000000.150000000000.100000000000.0559 (79.6)7741801756557703 year 98th percentile daily 1 hour max:0.200000000000.150000000000.100000000000.0546 (63.4)553460174445690* Based on 2004-2006 data for sites that are at least 75% complete for hours in a day and days in a quarter and has all 4 quarters and all 3 years.As such, these estimates are not based on the same air quality data that would be used to determine whether an area would attain a givenstandard or set of standards. These estimates can only approximate the number counties that are exceeding the given standardsand should be used with caution.** "Outside Resions" includeHawaii.Table 2. NO2Daily Maximums and Percentiles for 2004-2006.2004-2006NO2Daily MaximumsPercentilesLocation2nd3rd4th5th6th7th8th9th99th98thAtlanta0.0830.0790.0780.0740.0730.0720.0700.0700.0780.071Boston0.0690.0670.0640.0630.0620.0600.0590.0590.0640.059Chicago0.1030.0940.0930.0900.0900.0880.0880.0880.0930.088Cleveland0.0750.0740.0720.0700.0690.0660.0650.0640.0720.065Denver0.0940.0890.0860.0820.0790.0770.0730.0720.0860.077El Paso0.0850.0800.0750.0720.0710.0680.0670.0660.0750.067Las Vegas0.0420.0400.0390.0390.0380.0380.0370.0370.0390.037Los Angeles0.1100.0950.0950.0890.0880.0840.0830.0810.0950.083Miami0.0650.0600.0590.0580.0570.0560.0540.0530.0590.056New York0.1120.0990.0930.0900.0860.0840.0820.0810.0930.083Philadelphia0.0650.0620.0600.0590.0580.0570.0560.0540.0600.056Phoenix0.1070.0970.0930.0900.0890.0860.0840.0830.0930.085St. Louis0.0660.0650.0640.0640.0630.0630.0630.0630.0640.063Washington DC0.1020.0880.0790.0750.0720.0660.0650.0630.0790.065These are 14 of the 17 areas in the Draft REA; 3areas did not meet completeness requirements:Detroit, Jacksonville, and Provo.Based on 2004-2006 data for sites that are at least 75% complete for hours in a day and days in a quarter and has all 4 quarters and all 3 years.As such, these estimates are not based on the same air quality data that would be used to determine whether an area would attain agivenstandard or set of standards. These estimates can only approximate the number counties that are exceeding the given standardsand should be used with caution.2004-2006NO2Daily MaximumsPercentilesLocation2nd3rd4th5th6th7th8th9th99th98thDetroit *0.0620.0600.0580.0570.0560.0540.0540.0530.0580.054Detroit **0.0590.0570.0540.0530.0520.0520.0500.0500.0540.051Jacksonville ***0.0540.050.0490.0490.0490.0480.0480.0480.0490.048Provo ****0.0710.0660.0650.0650.0640.0630.0630.0620.0650.063* Detroit monitor 261630016 was complete for 2005 and 2006, 2004 was ignored in the averages.** Detroit monitor 261630019 was complete for 2004 and2006, 2005 was ignored in the averages.*** Jacksonville was only complete for 2006.**** Provo was only complete for 2004 and 2005.Table 3. Ratios of proposed alternatives and the current NO2standards.2004-2006Daily2004-2006Daily2004-20062005-20062004-20062005-20062004-20062005-20062004-20062005-2006Max24 hravgRatMax24 hravgRatDailyMaxAnnRatDailyMaxAnnRat24 hravgAnnRat24 hravgAnnRatLocation99th99th98th98th99th98th99th98thAtlanta0.0780.0421.840.0710.0381.880.0780.0184.360.0710.0184.000.0420.0182.370.0380.0182.13Boston0.0640.0431.500.0590.0391.500.0640.0232.730.0590.0232.500.0430.0231.810.0390.0231.66Chicago0.0930.0521.800.0880.0501.770.0930.0313.030.0880.0312.860.0520.0311.680.0500.0311.62Cleveland0.0720.0431.680.0650.0381.700.0720.0223.350.0650.0223.030.0430.0221.990.0380.0221.78Denver0.0860.0501.730.0770.0461.680.0860.0204.220.0770.0203.780.0500.0202.440.0460.0202.25El Paso0.0750.0381.990.0670.0351.910.0750.0184.090.0670.0183.650.0380.0182.050.0350.0181.91Las Vegas0.0390.0133.040.0370.0123.100.0390.0058.650.0370.0058.210.0130.0052.840.0120.0052.65Los Angeles0.0950.0611.560.0830.0551.500.0950.0313.060.0830.0312.700.0610.0311.970.0550.0311.79Miami0.0590.0301.970.0560.0272.060.0590.0087.410.0560.0087.030.0300.0083.760.0270.0083.42New York0.0930.0601.550.0830.0561.480.0930.0322.900.0830.0322.600.0600.0321.880.0560.0321.75Philadelphia0.0600.0401.510.0560.0351.610.0600.0173.620.0560.0173.340.0400.0172.400.0350.0172.07Phoenix0.0930.0571.630.0850.0531.600.0930.0322.950.0850.0322.700.0570.0321.810.0530.0321.69St. Louis0.0640.0341.910.0630.0312.030.0640.0173.820.0630.0173.740.0340.0171.990.0310.0171.84Washington DC0.0790.0451.760.0650.0401.610.0790.0213.700.0650.0213.020.0450.0212.100.0400.0211.88These are 14 of the 17 areas in the Draft REA; 3 areas did not meet completeness requirements:Detroit, Jacksonville, and Provo.Based on 2004-2006 data for sites that are at least 75% complete for hours in a day and days in a quarter and has all 4 quarters and all 3 years.As such, these estimates are not based on the same air quality data that would be used to determine whether an area would attain a givenstandard or set of standards. These estimates can only approximate the number counties that are exceeding the given standardsand should be used with caution.2004-2006Daily2004-2006Daily2004-20062005-20062004-20062005-20062004-20062005-20062004-20062005-2006Max24 hravgRatMax24 hravgRatDailyMaxAnnRatDailyMaxAnnRat24 hravgAnnRat24 hravgAnnRatLocation99th99th98th98th99th98th99th98thDetroit*0.0580.0381.530.0540.0351.540.0580.0192.980.0540.0192.780.0380.0191.950.0350.0191.80Detroit**0.0540.0341.570.0510.0321.560.0540.0143.810.0510.0143.600.0340.0142.430.0320.0142.31Jacksonville***0.0490.0271.840.0480.0241.980.0490.0124.220.0480.0124.140.0270.0122.290.0240.0122.09Provo****0.0650.0541.200.0630.0471.340.0650.0213.130.0630.0213.040.0540.0212.600.0470.0212.27* Detroit monitor 261630016 was complete for 2005 and 2006, 2004 was ignored in the averages.** Detroit monitor 261630019 was complete for 2004 and 2006, 2005 was ignored in the averages.*** Jacksonville was only complete for 2006.**** Provo was only complete for 2004 and 2005.