UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 6 1445 ROSS AVENUE, SUITE 1200 DALLAS, TX 75202·2733



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Ms. TeresaMarks Director Arkansas DepartmentofEnvironmental Quality 5301 Northshore Drive North Little Rock, AR 72118-5317

DearMs. Marks:

The U.S. Environmental Protection Agency (EPA) Region 6 has completed its analysis ofthe Arkansas Department ofEnvironmental Quality (ADEQ) 2010 Annual Air MonitoringNetWorkPlan to ensure it meets those requirements of40 CFRPart 58 and its appendices that confer approval authority on the Regional Administrator. We appreciate your cooperation and work to prepare and submit your 2010 network plan. EPAhas reviewed your airmonitoring network. and I am pleased to inform you that your 2010 networkplan is approved. Details regarding ourreview ofyour air monitoring network and minortechnical changes needed are addressed 

### in the enclosure.
Additionally, 

### in accordance with 40 CFRPart 58 App. D, 4.5(a)(ii), EPA approves your source-oriented leadmonitoring requirement waiverrequests at the following six facilities: EntergyArkansas Independence, Entergy Arkansas White Bluff, Georgia-Pacific LLC CrossettPaper Operations, Nucor Steel Arkansas, NucorYamato Steel Company and Quanex CorporationMacsteel Division. Approved lead monitoring waivers are required to be renewed once every five years as part ofthe network assessment required under 40 CPR 

### § 58.l0(d).

The network assessment process presents an opportunity for EPA and ADEQ to collaborate on air monitoring network design. 

### See 40 CFRPart 58 App. D, 1.1.2. We look forward to working with you on the implementation ofthe forthcoming ozone monitoring rule and the reconsidered leadmonitoring regulations.

Ifyou have any questions, please contact me at (214) 665-2100 or your staffmay contactMs. Maria Martinez ofmy staffat (214) 665-2230.

Enclosure

Recycledt'Recyclat* • Pmted Wfth V8Q8I8t*t 01 Based InIl!I on 100% Recydad Paper (40% POsloonsumer)Technical Comments on Arkansas Department ofEnvironrnental Quality (ADEQ) 2010 Annual Ambient AirMonitoring Network

Particulate Matter (PM):
According to the latest available census figures, ADEQ is required to have a minimum oftwo PM2.5 State or Local AirMonitoring Stations (SLAMS) in the Little Rock-North Little Rock Metropolitan Statistical Area (MSA). This analysis is based on the 2007 to 2009 design value of29.3 micrograms percubic meter (ug'm3) at the Adams Field site 

### (Air Quality System orAQS #05-119-1004), the 685,488 population estimate from the 2009 U.S. Census, and 40 CFR Part 58, App. D, 4.7.1 Table D-5. The currentPM2.5 network for this MSA meets the minimum SLAMS sites requirements. 

### See 40 CFRPart 58, App. D, 4.7.1.

A review ofthe PM2.5 data for the Memphis MSA shows PM2.5 monitors in the following counties: one in Crittenden County, AR, one in De Solo County, MS, and two in Shelby County, TN. The Memphis MSA meets theminimumrequirements oftwo PM2.5 SLAMS sites. This analysis is based on the design value of27.5 ug'rn3 (78% of the National Ambient AirQuality Standard (NAAQS» forthe Marion site (AQS #05-035-0005), thepopulation estimates from the 2009 U.S. Census, and 40 CFR Part 58, App. D, 4.7.1 Table D.5.
ADEQ operates collocated PMI0 manual monitors at the PARR site (AQS #05-119-0007) and a PMI0 manual monitorat the VA site (AQS #05·119-1007) in the Little Rock-North Little RockMSA. ADEQ meets the minimum PMI0 site requirements for this MSA. This analysis is based onthe population estimates from the 2009 U.S. Census, historical ambient PMI0 data, and 40 CPRPart 58, App. D, 4.6 Table D-4.

Since 2008, ADEQ has operated one PM2.5 samplerin Fayetteville-SpringdaleRoger, AR-MO MSA. Accordingto the 2010 networkplan, ADEQ is going to continue to operate one PM2.5 SLAMS monitor forthis MSA. ADEQ shouldre-evaluate the number ofPM2.5 sites required for this MSA next yearwhen there are three years ofdata in AQS. 

### See 40 CFR Part 58, App. D, 4.7.1(a).
ADEQ PM2.5 SLAMS monitors are reporting low ambient concentrations at the following sites: the Conway site (AQS# 05-045·0002), tlle DSR site (AQS # 05-119-1008), the EI Dorado site (AQS # 05-139-0006), the Hot Springs site (AQS #05-051-0003), the Russellville site (AQS #05·115-0003), the Stuttgart site (AQS #05-001-0011), the Crossett site (AQS #05-003-0005), the Newport site (AQS #05-067-0001), the Helena site (AQS #05·107·0001), the Mena site (AQS #05-113-0002), and the Searcy site (AQS #05-145-0001). Based on 2007-2009 data in AQS theirdesign values are 23.5 ug'm3 (67%), 26.8 ug'rn3 (77%),23.4 ug'rn3 (67%), 24 ug'm3 (69%),25 ug'm3 (71 %), 25.7 ug'rn3 (74%), 22.4 ug'm3 (64%),25 ug'm3 (72%),25 ug'm3 (71 %),23.8 ug'm3 (68%), and 26.3 ug'rn3 (75%) ofthe 24-hour2

NAAQS for PM2.5, respectively. ADEQ may want to re-evaluate these sites. Any request for a system modificationunder40 CFR 

### § 58.14(c) should be submitted in writing to the EPA Region 6.
According to Table 2 inthe annual network review, ADEQ operates all oftheir PM2.5 SLAMS monitors on a l-in-3 day sampling schedule except for the PARR site (AQS #05-119-0007) and the DSR site (AQS #05-119-1008). Thesetwo sites have a l-in-l day sampling schedule. Please note that manual PM2.5 SLAMS monitors must operate on at least a l-in-3 day sampling schedule at the following sites: National Core, Speciation Trends Network, and required regional background and regional transport sites. 

### See 40 CFR 

### § 58.12(d)(2) and (3). Ifthe remainingPM2.5 SLAMS sites' design values are within plus orminus 10percent ofthe 24-hourNAAQS and operateboth manual and continuous PM2.5 monitors, ADEQ may wantto re-evaluate these sites for
an opportunity to reduce sampling frequency and thereby reduce the use ofresources. ADEQ mayrequest areduction to a l-in-6 day sampling schedule. Please submit a written request to the EPARegion 6 ifyou wish to pursue authorization for a sampling frequency reduction. 

### See 40 CFR 

### § 58.12(d).

Table IB ofyour networkreview has designated the Marion site (AQS #O5-035'{)005) as the regional transport site for PM2.5. Please clarify whetherthe PM2.5 SLAMS monitor operating atthe Mena site (AQS #05-113-002) is the regional background 

### site. See 40 CFR Part 58, App. D, 4.7.3.


### Lead (Pb)
ADEQ's six Pb monitoring waivers are approved forEntergy Arkansas

- Independence, EntergyArkansas

- WhiteBluff; GeorgiaPacific LLC Crossett Paper Operations, Nucor Steel Arkansas, Nucor Yamato Steel Company, and Quanex Corporation MacSteel Division. 

### See 40 CFR Part58, App. D, 4.5(a). With the exception ofthe two EntergyArkansas locations (Independence and White Bluff), the 

### draft 2008 emissions inventory discloses thatthe Pb emissions are lowerthan 1.0 tonper year (tpy) from the sources. The waiver approvals for the Entergy Arkansas locations (Independence and White Bluff) are based onmodeling data. We also note that US Army Pine Bluffarsenal Pb emissions are temporarily lowerthan 1.0 tpy. Approved Pb monitoring waivers are required to be renewed once every five years in compliance with 40 CFR 

### § 58.lO(b)(IO) and 40 CFR 

### § 58.1O(b)(11). Ifthe approved Pb waiver circumstances significantlychange, as might fol1ow from a facility Pb emissions increase, the waiverrequests must be resubmitted sooner. 

### See 40 CFR 

### § 58.1O(b)(10) and App. D., 4.5(a)(ii). EPA's decision to approvethese waivers is based, in part, on the Pb source emissions (tpy) from the latest 2008 state inventory. Ifcircumstances change for a source, itmustbe includedin the state emissions inventory; therefore, it is critical that ADEQ maintain its state emissions inventory to support future decision making and review ofthese waivers. 

### See 40 CFR 

### § 51.20 and 

### § 51.30.
ADEQ must apply to EPA's Office ofResearch and Development for Pb Federal Effective Methods for their specific Inductively Coupled PlasmaMass Spectrometry Pb

### 3

analysis method andthe specific collection method. 

### See 40 CFR 

### § 50.16(a). Please note that the reference methods for Pb analysis and collectionboth utilize glass-fiberfilters. 

### See 40 CFRPart 50 App. G and Q.
Region 6 airmonitoring stafflooks forward to working withADEQ on the implementationofthe final Pb monitoring requirements. We expectthe final lead monitoringrequirements to be addressed as specified in

### the reconsidered leadmonitoring regulations signed December 14, 2010. We advise all monitoring agencies to refrain from siting and installing Pb non-source orientedmonitors until the final Pb reconsiderationmonitoringregulations are promulgated. ADEQ has listed the PARR site (AQS#05-119-0007) as a non-source oriented Pb monitoring site and as not comparable to.theNAAQS. Please note that Pb monitoring sites are expectedto he Ph NAAQS comparable. Furthermore, Table IB inyourannual networkplandesignates the operating schedule for Ph as daily l-in-3. Note the regulations allow for l-in-6 day sampling schedule for Pb manual methods. 

### See 40 CFR 

### § 58.12(b).