TO: R. Scott Davis, Chief 

Air Planning Branch 1. 

FROM: Gregg M. Worley, Chief bCXJ >'I\·~ 

Air Toxics & Monitoring Branch 

DATE: August 8, 2014 

SUBJECT: Data Completeness for Certain Georgia Areas 

The following areas in Georgia have invalid design values for particulate matter less than 2.5 microns 

(PM2.s) for the 2011-2013 design value period but may have valid 2012-2014 design values once 2014 

data is certified by the state: Augusta, Columbus, Savannah, Valdosta, and Washington County. The 

2011-2013 design values for these areas are invalid due to incomplete data during this time period 

resulting primarily from the January 9-10, 20 11, winter storm that encompassed large portions of north 

and central Georgia causing power outages affecting monitoring sites and the state's laboratory (see 

Appendix A for a map showing snow and ice accumulation across the state). 

The Georgia Environmental Protection Division (GEPD) laboratory is located in northeast Atlanta in 

Norcross, Georgia (Gwinnett County). This laboratory provides the PM2.s gravimetric weighing service 

for GEPD's PM2.s ambient air monitoring program. Most PM2.s filter samples across the state were 

affected from January 9 through February 23, 2011. The actual number of missed sampling days due to 

the ice storm varies by monitoring site, because all sites are not on the same sampling frequency. This 

can range from 8 to 45 missed samples per monitor. The impact of the storm on the laboratory is 

illustrated by the amount of data invalidated by GEPD in the first quarter versus the second quarter of 

2011. In the first quarter of 2011 when the storm occurred, GEPD flagged 650 out of 1371 total samples 

across the state (47.4%) in AQS for laboratory error. In the second quarter of 2011, GEPD flagged one 

of 1367 total samples across the state (0.00073%) in AQS for laboratory error. 

GEPD included the following information on the impacts of the storm in a draft technical analysis 

provided to Region 4: 

"It is important to note that all of the Georgia monitors, except for South DeKalb. have 

incomplete data for the first quarter of 2011. This was due to circumstances out of EPD's 

control that resulted from a snow and ice storm from January 9 through 11, 2011. The storm 

caused problems with the power and environmental control systems for the EPD Laboratory 

which lost power on and off during the following week. The systems were brought back on line 

by Friday, January 14; however, the weighing rooms could not be stabilized until February 2. 

twenty four days after the storm began. In order to meet federal ambient monitor sampling 

Internet Address (UAL) • http://www.epa.gov 

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deadlines, both pre-and post-sample weighing had to be conducted during this period. 

Furthermore, samples could not have been prepared or taken through the preparation process at 

another laboratory (commercial, federal, state or academic) and still meet federal sampling 

requirements." 

While GEPD was able to open a large portion of the laboratory shortly after the storm, the state 

indicated in its report that the temperature and humidity of the PM2.s gravimetric weigh lab was not able 

to be stabilized until February 2, 2011. After reviewing the number of days GEPD invalidated samples, 

the EPA Region 4 believes the weigh lab was experiencing temperature and humidity control issues 

through February 23. Temperature and humidity control ranges are among parameters identified as 

"critical criteria" in the federal reference method for PM2.s found in 40 CFR Part 50, Appendix L. 

Accordingly, when filters are weighed outside of these allowable ranges, the associated data should be 

considered invalid for regulatory purposes unless there is a compelling reason and justification for not 

doing so. These issues affected sample preparation (i.e., pre-weighs) and analysis (i.e., post-weighs) 

through February 23 for all sites in the state except the South DeKalb site which has a continuous 

federal equivalent method monitor. GEPD, as part of their normal quality assurance procedures, 

invalidated the data from January 9 through February 23, 2011, that was impacted by the storm and 

entered "null codes" for these data in AQS. PM2.s data for the second, third, and fourth quarters of 2011 

is complete for many areas, including Augusta, Columbus, Savannah, Valdosta, and Washington 

County. 

While the majority of the data issues for the 2011-2013 design value period were due to the 2011 winter 

storm, several sites across the state, including the Columbus, Savannah, and Valdosta areas, experienced 

additional data completeness issues in 2012. There are no data completeness issues in 2013 for the 

Augusta, Columbus, Savannah, Valdosta, or Washington County areas. GEPD invalidated an unusually 

high percentage of PM2.s data from several sites in 2012 because of damage to the PM2.s filters. Upon 

discussing this with GEPD, EPA understands that several factors may have contributed to this high rate 

of invalidation due to filter damage, including sample handling procedures (GEPD was freezing its 

PM2j filters before they were used, which is not common), site operator procedures, a change in the 

national manufacturer of PM2.s filters in 2012, and the acceptance criteria established by the GEPD for 

filter damage. In July 2013, GEPD contacted EPA's Office of Air Quality Planning & Standards about 

the filter damage issue that it experienced at several sites across their network in 2012 and the 

procedures that it is using to minimize filter damage during shipping and handling. GEPD adopted a 

number of corrective actions that appear to have greatly mitigated this problem at most sites in 2013 to 

present. 

As you are aware, GEPD is the only agency in Georgia with an ambient air monitoring program. There 

are no local agencies to take on managing remote sites in the network. In some areas where monitoring 

is conducted but may not be federally required, GEPD may experience other issues affecting data 

completeness. It is possible that changes in the shipping and handling procedures incorporated in other 
year because a majority of the data completeness issues for these areas is associated with the 2011 

winter storm discussed above. Furthermore, based on the changes to the filter handling procedures 

mentioned above and the improved data completeness percentages in 2013, EPA has no reason to 

believe at this time that the 2014 data will be incomplete. 

Let us know if there is any other information needed by you or your staff.