UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION 6

1445 ROSS AVENUE, SUITE 1200

DALLAS, TX 75202·2733

,

JAN t 0 ZOIl

Ms. Teresa Marks

Director

Arkansas Department ofEnvironmental Quality

5301 Northshore Drive

North Little Rock, AR 72118-5317

Dear Ms. Marks:

The U.S. Environmental Protection Agency (EPA) Region 6 has completed its

analysis ofthe Arkansas Department ofEnvironmental Quality (ADEQ) 2010 Annual Air

Monitoring NetWork Plan to ensure it meets those requirements of40 CFR Part 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. EPA has

reviewed your air monitoring network. and I am pleased to inform you that your 2010

network plan is approved. Details regarding our review of your air monitoring network

and minor technical changes needed are addressed in the enclosure.

Additionally, in accordance with 40 CFR Part 58 App. D, 4.5(a)(ii), EPA

approves your source-oriented lead monitoring requirement waiver requests at the

following six facilities: Entergy Arkansas Independence, Entergy Arkansas White Bluff,

Georgia-Pacific LLC Crossett Paper Operations, Nucor Steel Arkansas, Nucor Yamato

Steel Company and Quanex Corporation Macsteel 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 CFR Part 58 App. D, 1.1.2. We

look forward to working with you on the implementation ofthe forthcoming ozone

monitoring rule and the reconsidered lead monitoring regulations.

If you have any questions, please contact me at (214) 665-2100 or your staffmay

contact Ms. Maria Martinez ofmy staff at (214) 665-2230.

Enclosure

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Technical Comments on Arkansas Department ofEnvironrnental Quality (ADEQ) 2010

Annual Ambient Air Monitoring Network

Particulate Matter (PM):

According to the latest available census figures, ADEQ is required to have a

minimum oftwo PM2.5 State or Local Air Monitoring Stations (SLAMS) in the

Little Rock-North Little Rock Metropolitan Statistical Area (MSA). This analysis is

based on the 2007 to 2009 design value of 29.3 micrograms per cubic meter (ug'm3) at

the Adams Field site (Air Quality System or AQS #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

current PM2.5 network for this MSA meets the minimum SLAMS sites requirements.

See 40 CFR Part 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 the minimum requirements oftwo

PM2.5 SLAMS sites. This analysis is based on the design value of27.5 ug'rn3 (78% of

the National Ambient Air Quality Standard (NAAQS» for the Marion site (AQS

#05-035-0005), the population 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 monitor at the VA site (AQS #05·119-1007) in the

Little Rock-North Little Rock MSA. ADEQ meets the minimum PMI0 site requirements

for this MSA. This analysis is based on the population estimates from the 2009 U.S.

Census, historical ambient PMI0 data, and 40 CPR Part 58, App. D, 4.6 Table D-4.

Since 2008, ADEQ has operated one PM2.5 sampler in Fayetteville-SpringdaleRoger, AR-MO MSA. According to the 2010 network plan, ADEQ is going to continue

to operate one PM2.5 SLAMS monitor for this MSA. ADEQ should re-evaluate the

number ofPM2.5 sites required for this MSA next year when 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 their design 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-hour
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NAAQS for PM2.5, respectively. ADEQ may want to re-evaluate these sites. Any

request for a system modification under 40 CFR § 58.14(c) should be submitted in

writing to the EPA Region 6.

According to Table 2 in the 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). These two 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 remaining PM2.5 SLAMS sites' design

values are within plus or minus 10 percent ofthe 24-hour NAAQS and operate both

manual and continuous PM2.5 monitors, ADEQ may want to re-evaluate these sites for

an opportunity to reduce sampling frequency and thereby reduce the use ofresources.

ADEQ may request a reduction to a l-in-6 day sampling schedule. Please submit a

written request to the EPA Region 6 if you wish to pursue authorization for a sampling

frequency reduction. See 40 CFR § 58.12(d).

Table IB of your network review has designated the Marion site (AQS

#O5-035'{)005) as the regional transport site for PM2.5. Please clarify whether the PM2.5

SLAMS monitor operating at the 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 for Entergy Arkansas -

Independence, Entergy Arkansas - White Bluff; Georgia Pacific LLC Crossett Paper

Operations, Nucor Steel Arkansas, Nucor Yamato Steel Company, and Quanex

Corporation MacSteel Division. See 40 CFR Part 58, App. D, 4.5(a). With the exception

ofthe two Entergy Arkansas locations (Independence and White Bluff), the draft 2008

emissions inventory discloses that the Pb emissions are lower than 1.0 ton per year (tpy)

from the sources. The waiver approvals for the Entergy Arkansas locations

(Independence and White Bluff) are based on modeling data. We also note that US Army

Pine Bluff arsenal Pb emissions are temporarily lower than 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 significantly change, as might fol1ow from a facility Pb emissions

increase, the waiver requests must be resubmitted sooner. See 40 CFR § 58.1O(b)(10)

and App. D., 4.5(a)(ii). EPA's decision to approve these waivers is based, in part, on the

Pb source emissions (tpy) from the latest 2008 state inventory. Ifcircumstances change

for a source, it must be included in 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 Plasma Mass Spectrometry Pb
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analysis method and the specific collection method. See 40 CFR § 50.16(a). Please note

that the reference methods for Pb analysis and collection both utilize glass-fiber filters.

See 40 CFR Part 50 App. G and Q.

Region 6 airmonitoring stafflooks forward to working with ADEQ on the

implementation ofthe final Pb monitoring requirements. We expect the final lead

monitoring requirements to be addressed as specified in the reconsidered lead monitoring

regulations signed December 14, 2010. We advise all monitoring agencies to refrain

from siting and installing Pb non-source oriented monitors until the final Pb

reconsideration monitoring regulations 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 .the NAAQS. Please note that Pb monitoring sites are expected to he Ph NAAQS

comparable. Furthermore, Table IB in your annual network plan designates 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).