### 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:2013 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:2013 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 8460 0.09 0.078 0.078 0.075 0 0.00 214 213 100 1 None 1 110010041 420 34th Street N.E.,Washington, Dc 20019Washington District of Columbia DC 03

1 HOUR 86300.083 0.081 0.079 0.078 0 0.00 214 211 99 3 None 1 1100100432500 1st Street, N.W. Washington Dc Washington District of Columbia DC 03

1 HOUR 55690.081 0.081 0.077 0.074 0 0.00 214 90 42 1 None 1 110010050301 Van Buren Street, N.W. Washington Dc 20012 Washington District of Columbia DC 03

1 HOUR 50980.082 0.077 0.075 0.073 0 0.00 214 211 99 0 None 1 240090011 350 Stafford Road Prince Frederick Calvert MD 03

1 HOUR 4751 0.075 0.073 0.072 0.07 0 0.00 214 199 93 2 None 1 24017001014320 Oaks Road Charlotte HallCharles MD 03

1 HOUR 50160.086 0.081 0.077 0.077 0 0.00 214 207 97 3 None 1 240210037Frederick County Airport ,180 E Airport Drive Frederick Frederick MD 03

1 HOUR 50480.086 0.083 0.077 0.077 0 0.00 214 210 98 1 None 1 240313001 Lathrop E. Smith Environmental Education Center, 5110 Meadowside Lane Rockville Montgomery MD 03

1 HOUR 8717 0.089 0.087 0.079 0.079 0 0.00 214 213 100 1 None 1 240330030Howard University'S Beltsville Laboratory, 12003 Old Baltimore Pike Beltsville Prince George's MD 03

1 HOUR 5112 0.083 0.082 0.078 0.078 0 0.00 214 214 100 0 None 1 240338003Pg County Equestrian Center, 14900 Pennsylvania Ave. Greater Upper Marlboro Prince

George's MD 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:2013 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 74800.102 0.093 0.092 0.091 0 0.00 214 185 86 4 None 1 240339991 Powder Mill Rd, Laurel, Md 20708 Not in a city Prince George's MD 03

1 HOUR 5111 0.092 0.083 0.078 0.077 0 0.00 214 213 100 1 None 1 510130020S 18th And Hayes St Arlington Arlington VA 03

1 HOUR 5115 0.083 0.08 0.08 0.072 0 0.00 214 212 99 2 None 1 510590030Sta. 46-B9, Lee Park, Telegraph Road Groveton Fairfax VA 03

1 HOUR 5055 0.066 0.065 0.063 0.063 0 0.00 214 212 99 0 None 1 510610002Rt651 C Phelps Wildlife Management Area Not in a city Fauquier VA 03

1 HOUR 50890.088 0.078 0.076 0.073 0 0.00 214 214 100 0 None 1 51107100538-I, Broad Run High School, Ashburn Not in a city Loudoun VA 03

1 HOUR 5095 0.078 0.0740.072 0.07 0 0.00 214 214 100 0 None 1 511530009James S. Long Park Not in a city Prince William VA 03

1 HOUR 50960.078 0.071 0.07 0.067 0 0.00 214 214 100 0 None 1 511790001 Widewater Elem. Sch., Den Rich Road Aquia Harbour Stafford VA 03

1 HOUR 48160.088 0.082 0.079 0.077 0 0.00 214 200 93 4 None 1 515100021 3200 Colvin Street Not in a city 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:2013 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:2013 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 85150.071 0.069 0.062 0.062 0 0.00 214 212 99 0 None 1 110010041 420 34th Street N.E.,Washington, Dc 20019 Washington District of Columbia DC 03

8-HR RUN AVG BEGIN HOUR 8672 0.068 0.066 0.066 0.066 0 0.00 214 211 99 0 None 1 1100100432500 1st Street, N.W. Washington Dc Washington District of Columbia DC 03

8-HR RUN AVG BEGIN HOUR 55950.068 0.067 0.067 0.066 0 0.00 214 90 42 0 None 1 110010050301 Van Buren Street, N.W. Washington Dc 20012 Washington District of Columbia DC 03

8-HR RUN AVG BEGIN HOUR 5082 0.072 0.072 0.071 0.067 0 0.00 214 211 99 0 None 1 240090011 350 Stafford Road Prince Frederick Calvert MD 03

8-HR RUN AVG BEGIN HOUR 47280.069 0.066 0.066 0.064 0 0.00 214 193 90 0 None 1 24017001014320 Oaks Road Charlotte Hall Charles MD 03

8-HR RUN AVG BEGIN HOUR 4997 0.076 0.069 0.069 0.069 1 1.00 214 207 97 0 None 1 240210037Frederick County Airport ,180 E Airport Drive Frederick Frederick MD 03

8-HR RUN AVG BEGIN HOUR 50380.072 0.07 0.069 0.069 0 0.00 214 209 98 0 None 1 240313001 Lathrop E. Smith Environmental Education Center, 5110 Meadowside Lane Rockville Montgomery 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:2013 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 87100.074 0.072 0.071 0.068 0 0.00 214 213 100 0 None 1 240330030Howard University'S Beltsville Laboratory, 12003 Old Baltimore Pike Beltsville Prince George's MD 03

8-HR RUN AVG BEGIN HOUR 51150.072 0.07 0.069 0.069 0 0.00 214 214 100 0 None 1 240338003Pg County Equestrian Center, 14900 Pennsylvania Ave. Greater Upper Marlboro Prince

George's MD 03

8-HR RUN AVG BEGIN HOUR 76180.077 0.077 0.074 0.072 2 2.40 214 175 82 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 51060.075 0.07 0.067 0.067 0 0.00 214 212 99 0 None 1 510130020S 18th And Hayes St Arlington Arlington VA 03

8-HR RUN AVG BEGIN HOUR 5113 0.076 0.068 0.067 0.067 1 1.00 214 212 99 0 None 1 510590030Sta. 46-B9, Lee Park, Telegraph Road Groveton Fairfax VA 03

8-HR RUN AVG BEGIN HOUR 50760.064 0.06 0.059 0.059 0 0.00 214 211 99 0 None 1 510610002Rt651 C Phelps Wildlife Management Area Not in a city Fauquier VA 03

8-HR RUN AVG BEGIN HOUR 51150.075 0.071 0.069 0.066 0 0.00 214 214 100 0 None 1 51107100538-I, Broad Run High School, Ashburn Not in a city Loudoun VA 03

8-HR RUN AVG BEGIN HOUR 5121 0.07 0.067 0.066 0.066 0 0.00 214 214 100 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:2013 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 51140.071 0.065 0.064 0.064 0 0.00 214 213 100 0 None 1 511790001 Widewater Elem. Sch., Den Rich Road Aquia Harbour Stafford VA 03

8-HR RUN AVG BEGIN HOUR 47400.075 0.071 0.066 0.063 0 0.00 214 194 91 0 None 1 515100021 3200 Colvin Street Not in a city Alexandria City VA 03