### Page 1 of 5 Generated: August 22, 2014 Source: U.S. EPA AirData <http://www.epa.gov/airdata> This report is based on monitor-level summary statistics. Air quality standards for some pollutants (PM2.5 and Pb) allow for combining data from multiple monitors into a site-level summary statistic that can be compared to the standard. In those cases, the site-level statistics may differ from the monitor-level statistics upon which this report is based. Readers are cautioned not to rank order geographic areas based on AirData reports. Air pollution levels measured at a particular monitoring site are not necessarily representative of the air quality for an entire county or urban area. AirData reports are produced from a direct query of the AQS Data Mart. The data represent the best and most recent information available to EPA from state agencies. However, some values may be absent due to incomplete reporting, and some values may change due to quality assurance activities. The AQS database is updated daily by state, local, and tribal organizations who own and submit the data. Please contact the appropriate air quality monitoring agency to report any data problems. <http://www.epa.gov/airquality/airdata/ad_contacts.html> Get detailed information about this report, including column descriptions, at http://www.epa.gov/airquality/airdata/ad_about_reports.html#mon 

# Monitor Values Report Geographic Area:Washington-Arlington-Alexandria, DC-VA-MD-WV Pollutant:Ozone Year:2011 Exceptional Events:Included (if any)

Page 1 of 5 Generated: August 22, 2014 Source: U.S. EPA AirData <http://www.epa.gov/airdata> This report is based on monitor-level summary statistics. Air quality standards for some pollutants (PM2.5 and Pb) allow for combining data from multiple monitors into a site-level summary statistic that can be compared to the standard. In those cases, the site-level statistics may differ from the monitor-level statistics upon which this report is based. Readers are cautioned not to rank order geographic areas based on AirData reports. Air pollution levels measured at a particular monitoring site are not necessarily representative of the air quality for an entire county or urban area. AirData reports are produced from a direct query of the AQS Data Mart. The data represent the best and most recent information available to EPA from state agencies. However, some values may be absent due to incomplete reporting, and some values may change due to quality assurance activities. The AQS database is updated daily by state, local, and tribal organizations who own and submit the data. Please contact the appropriate air quality monitoring agency to report any data problems. <http://www.epa.gov/airquality/airdata/ad_contacts.html> Get detailed information about this report, including column descriptions, at http://www.epa.gov/airquality/airdata/ad_about_reports.html#mon 

# Monitor Values Report Geographic Area:Washington-Arlington-Alexandria, DC-VA-MD-WV Pollutant:Ozone Year:2011 Exceptional Events:Included (if any)

Duration Description=1 HOUR

Duration Description Obs First

Max Second Max Third Max Fourth Max Actual Exc Est Exc Required Days Valid

Days Percent Days Missing

Days Exc EventsMonitor Number Site ID Address City County State EPA Region

1 HOUR 85700.101 0.099 0.096 0.095 0 0.00 214 209 98 0 None 1 110010041 420 34th Street N.E.,Washington, Dc 20019Washington District of Columbia DC 03

1 HOUR 84340.107 0.101 0.101 0.096 0 0.00 214 204 95 0 None 1 1100100432500 1st Street, N.W. Washington Dc Washington District of Columbia DC 03

1 HOUR 5031 0.109 0.107 0.107 0.095 0 0.00 214 210 98 2 None 1 240090011 350 Stafford Road Prince Frederick Calvert MD 03

1 HOUR 49640.108 0.098 0.096 0.095 0 0.00 214 206 96 0 None 1 24017001014320 Oaks Road Charlotte HallCharles MD 03

1 HOUR 5117 0.09 0.089 0.084 0.083 0 0.00 214 214 100 0 None 1 240210037Frederick County Airport ,180 E Airport Drive Frederick Frederick MD 03

1 HOUR 50840.097 0.097 0.096 0.092 0 0.00 214 211 99 2 None 1 240313001 Lathrop E. Smith Environmental Education Center, 5110 Meadowside Lane Rockville Montgomery MD 03

1 HOUR 79890.114 0.109 0.093 0.093 0 0.00 214 190 89 3 None 1 240330030Howard University'S Beltsville Laboratory, 12003 Old Baltimore Pike Beltsville Prince George's MD 03

1 HOUR 5107 0.11 0.11 0.106 0.105 0 0.00 214 213 100 1 None 1 240338003Pg County Equestrian Center, 14900 Pennsylvania Ave. Greater Upper Marlboro Prince

George's MD 03

1 HOUR 58400.113 0.102 0.097 0.095 0 0.00 214 185 86 3 None 1 240339991 Powder Mill Rd, Laurel, Md 20708 Not in a city Prince George's MD 03

1 HOUR 51040.109 0.103 0.102 0.098 0 0.00 214 212 99 2 None 1 510130020S 18th And Hayes St Arlington Arlington VA 03

### Page 2 of 5 Generated: August 22, 2014 Source: U.S. EPA AirData <http://www.epa.gov/airdata> This report is based on monitor-level summary statistics. Air quality standards for some pollutants (PM2.5 and Pb) allow for combining data from multiple monitors into a site-level summary statistic that can be compared to the standard. In those cases, the site-level statistics may differ from the monitor-level statistics upon which this report is based. Readers are cautioned not to rank order geographic areas based on AirData reports. Air pollution levels measured at a particular monitoring site are not necessarily representative of the air quality for an entire county or urban area. AirData reports are produced from a direct query of the AQS Data Mart. The data represent the best and most recent information available to EPA from state agencies. However, some values may be absent due to incomplete reporting, and some values may change due to quality assurance activities. The AQS database is updated daily by state, local, and tribal organizations who own and submit the data. Please contact the appropriate air quality monitoring agency to report any data problems. <http://www.epa.gov/airquality/airdata/ad_contacts.html> Get detailed information about this report, including column descriptions, at http://www.epa.gov/airquality/airdata/ad_about_reports.html#mon 

# Monitor Values Report Geographic Area:Washington-Arlington-Alexandria, DC-VA-MD-WV Pollutant:Ozone Year:2011 Exceptional Events:Included (if any)

Duration Description=1 HOUR

Duration Description Obs First

Max Second Max Third Max Fourth Max Actual Exc Est Exc Required Days Valid

Days Percent Days Missing

Days Exc EventsMonitor Number Site ID Address City County State EPA Region

1 HOUR 5115 0.11 0.106 0.1 0.096 0 0.00 214 212 99 2 None 1 510590030Sta. 46-B9, Lee Park, Telegraph Road Groveton Fairfax VA 03

1 HOUR 50950.077 0.076 0.074 0.069 0 0.00 214 213 100 1 None 1 510610002Rt651 C Phelps Wildlife Management Area Not in a city Fauquier VA 03

1 HOUR 51040.098 0.086 0.085 0.084 0 0.00 214 212 99 2 None 1 51107100538-I, Broad Run High School, Ashburn Not in a city Loudoun VA 03

1 HOUR 5007 0.083 0.08 0.078 0.077 0 0.00 214 209 98 0 None 1 511530009James S. Long Park Not in a city Prince William VA 03

1 HOUR 5107 0.097 0.097 0.085 0.084 0 0.00 214 214 100 0 None 1 511790001 Widewater Elem. Sch., Den Rich Road Aquia Harbour Stafford VA 03

1 HOUR 50540.109 0.103 0.102 0.096 0 0.00 214 212 99 2 None 1 515100009517 N Saint Asaph St, Alexandria Health Alexandria Alexandria City VA 03

### Page 3 of 5 Generated: August 22, 2014 Source: U.S. EPA AirData <http://www.epa.gov/airdata> This report is based on monitor-level summary statistics. Air quality standards for some pollutants (PM2.5 and Pb) allow for combining data from multiple monitors into a site-level summary statistic that can be compared to the standard. In those cases, the site-level statistics may differ from the monitor-level statistics upon which this report is based. Readers are cautioned not to rank order geographic areas based on AirData reports. Air pollution levels measured at a particular monitoring site are not necessarily representative of the air quality for an entire county or urban area. AirData reports are produced from a direct query of the AQS Data Mart. The data represent the best and most recent information available to EPA from state agencies. However, some values may be absent due to incomplete reporting, and some values may change due to quality assurance activities. The AQS database is updated daily by state, local, and tribal organizations who own and submit the data. Please contact the appropriate air quality monitoring agency to report any data problems. <http://www.epa.gov/airquality/airdata/ad_contacts.html> Get detailed information about this report, including column descriptions, at http://www.epa.gov/airquality/airdata/ad_about_reports.html#mon 

# Monitor Values Report Geographic Area:Washington-Arlington-Alexandria, DC-VA-MD-WV Pollutant:Ozone Year:2011 Exceptional Events:Included (if any)

Page 3 of 5 Generated: August 22, 2014 Source: U.S. EPA AirData <http://www.epa.gov/airdata> This report is based on monitor-level summary statistics. Air quality standards for some pollutants (PM2.5 and Pb) allow for combining data from multiple monitors into a site-level summary statistic that can be compared to the standard. In those cases, the site-level statistics may differ from the monitor-level statistics upon which this report is based. Readers are cautioned not to rank order geographic areas based on AirData reports. Air pollution levels measured at a particular monitoring site are not necessarily representative of the air quality for an entire county or urban area. AirData reports are produced from a direct query of the AQS Data Mart. The data represent the best and most recent information available to EPA from state agencies. However, some values may be absent due to incomplete reporting, and some values may change due to quality assurance activities. The AQS database is updated daily by state, local, and tribal organizations who own and submit the data. Please contact the appropriate air quality monitoring agency to report any data problems. <http://www.epa.gov/airquality/airdata/ad_contacts.html> Get detailed information about this report, including column descriptions, at http://www.epa.gov/airquality/airdata/ad_about_reports.html#mon 

# Monitor Values Report Geographic Area:Washington-Arlington-Alexandria, DC-VA-MD-WV Pollutant:Ozone Year:2011 Exceptional Events:Included (if any)

Duration Description=8-HR RUN AVG BEGIN HOUR

Duration Description Obs First

Max Second Max Third Max Fourth Max Actual Exc Est Exc Required Days Valid

Days Percent Days Missing

Days Exc EventsMonitor Number Site ID Address City County State EPA Region

8-HR RUN AVG BEGIN HOUR 86200.085 0.0840.082 0.08 6 6.20 214 207 97 0 None 1 110010041 420 34th Street N.E.,Washington, Dc 20019 Washington District of Columbia DC 03

8-HR RUN AVG BEGIN HOUR 84660.092 0.087 0.086 0.085 11 11.60 214 203 95 0 None 1 1100100432500 1st Street, N.W. Washington Dc Washington District of Columbia DC 03

8-HR RUN AVG BEGIN HOUR 5023 0.093 0.092 0.087 0.082 6 6.20 214 206 96 0 None 1 240090011 350 Stafford Road Prince Frederick Calvert MD 03

8-HR RUN AVG BEGIN HOUR 4957 0.098 0.087 0.086 0.085 7 7.30 214 205 96 0 None 1 24017001014320 Oaks Road Charlotte Hall Charles MD 03

8-HR RUN AVG BEGIN HOUR 5121 0.085 0.082 0.078 0.077 6 6.00 214 214 100 0 None 1 240210037Frederick County Airport ,180 E Airport Drive Frederick Frederick MD 03

8-HR RUN AVG BEGIN HOUR 50790.088 0.085 0.082 0.081 5 5.10 214 210 98 0 None 1 240313001 Lathrop E. Smith Environmental Education Center, 5110 Meadowside Lane Rockville Montgomery MD 03

8-HR RUN AVG BEGIN HOUR 79460.094 0.091 0.088 0.083 7 8.20 214 182 85 0 None 1 240330030Howard University'S Beltsville Laboratory, 12003 Old Baltimore Pike Beltsville Prince George's MD 03

### Page 4 of 5 Generated: August 22, 2014 Source: U.S. EPA AirData <http://www.epa.gov/airdata> This report is based on monitor-level summary statistics. Air quality standards for some pollutants (PM2.5 and Pb) allow for combining data from multiple monitors into a site-level summary statistic that can be compared to the standard. In those cases, the site-level statistics may differ from the monitor-level statistics upon which this report is based. Readers are cautioned not to rank order geographic areas based on AirData reports. Air pollution levels measured at a particular monitoring site are not necessarily representative of the air quality for an entire county or urban area. AirData reports are produced from a direct query of the AQS Data Mart. The data represent the best and most recent information available to EPA from state agencies. However, some values may be absent due to incomplete reporting, and some values may change due to quality assurance activities. The AQS database is updated daily by state, local, and tribal organizations who own and submit the data. Please contact the appropriate air quality monitoring agency to report any data problems. <http://www.epa.gov/airquality/airdata/ad_contacts.html> Get detailed information about this report, including column descriptions, at http://www.epa.gov/airquality/airdata/ad_about_reports.html#mon 

# Monitor Values Report Geographic Area:Washington-Arlington-Alexandria, DC-VA-MD-WV Pollutant:Ozone Year:2011 Exceptional Events:Included (if any)

Duration Description=8-HR RUN AVG BEGIN HOUR

Duration Description Obs First

Max Second Max Third Max Fourth Max Actual Exc Est Exc Required Days Valid

Days Percent Days Missing

Days Exc EventsMonitor Number Site ID Address City County State EPA Region

8-HR RUN AVG BEGIN HOUR 5087 0.095 0.092 0.09 0.086 14 14.10 214 213 100 0 None 1 240338003Pg County Equestrian Center, 14900 Pennsylvania Ave. Greater Upper Marlboro Prince

George's MD 03

8-HR RUN AVG BEGIN HOUR 58450.092 0.086 0.085 0.084 7 8.30 214 181 85 0 None 1 240339991 Powder Mill Rd, Laurel, Md 20708 Not in a city Prince George's MD 03

8-HR RUN AVG BEGIN HOUR 5101 0.1 0.093 0.089 0.087 8 8.10 214 212 99 0 None 1 510130020S 18th And Hayes St Arlington Arlington VA 03

8-HR RUN AVG BEGIN HOUR 51190.099 0.096 0.09 0.087 11 11.10 214 212 99 0 None 1 510590030Sta. 46-B9, Lee Park, Telegraph Road Groveton Fairfax VA 03

8-HR RUN AVG BEGIN HOUR 51180.067 0.065 0.065 0.063 0 0.00 214 212 99 0 None 1 510610002Rt651 C Phelps Wildlife Management Area Not in a city Fauquier VA 03

8-HR RUN AVG BEGIN HOUR 5113 0.086 0.081 0.08 0.075 3 3.00 214 212 99 0 None 1 51107100538-I, Broad Run High School, Ashburn Not in a city Loudoun VA 03

8-HR RUN AVG BEGIN HOUR 5017 0.079 0.073 0.071 0.071 1 1.00 214 208 97 0 None 1 511530009James S. Long Park Not in a city Prince William VA 03

### Page 5 of 5 Generated: August 22, 2014 Source: U.S. EPA AirData <http://www.epa.gov/airdata> This report is based on monitor-level summary statistics. Air quality standards for some pollutants (PM2.5 and Pb) allow for combining data from multiple monitors into a site-level summary statistic that can be compared to the standard. In those cases, the site-level statistics may differ from the monitor-level statistics upon which this report is based. Readers are cautioned not to rank order geographic areas based on AirData reports. Air pollution levels measured at a particular monitoring site are not necessarily representative of the air quality for an entire county or urban area. AirData reports are produced from a direct query of the AQS Data Mart. The data represent the best and most recent information available to EPA from state agencies. However, some values may be absent due to incomplete reporting, and some values may change due to quality assurance activities. The AQS database is updated daily by state, local, and tribal organizations who own and submit the data. Please contact the appropriate air quality monitoring agency to report any data problems. <http://www.epa.gov/airquality/airdata/ad_contacts.html> Get detailed information about this report, including column descriptions, at http://www.epa.gov/airquality/airdata/ad_about_reports.html#mon 

# Monitor Values Report Geographic Area:Washington-Arlington-Alexandria, DC-VA-MD-WV Pollutant:Ozone Year:2011 Exceptional Events:Included (if any)

Duration Description=8-HR RUN AVG BEGIN HOUR

Duration Description Obs First

Max Second Max Third Max Fourth Max Actual Exc Est Exc Required Days Valid

Days Percent Days Missing

Days Exc EventsMonitor Number Site ID Address City County State EPA Region

8-HR RUN AVG BEGIN HOUR 5127 0.086 0.08 0.075 0.074 2 2.00 214 214 100 0 None 1 511790001 Widewater Elem. Sch., Den Rich Road Aquia Harbour Stafford VA 03

8-HR RUN AVG BEGIN HOUR 5065 0.1 0.095 0.09 0.084 7 7.10 214 212 99 0 None 1 515100009517 N Saint Asaph St, Alexandria Health Alexandria Alexandria City VA 03