Mr. Richard C. Chism 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGIONS 

1445 ROSS AVENUE, SUITE 1200 

DALLAS TX 75202-2733 

OCT 2 6 2015 

Director, Monitoring Division (MC 165) 

Texas Commission on 

Environmental Quality 

Post Office Box 13087 

Austin, TX 78711-3087 

Dear Mr. Chism: 

Thank you for your correspondence submitting the Texas Commission on Environmental Quality's 

(TCEQ) 2015 Annual Monitoring Network Plan. Thank you also for your letter dated April 7, 2015, 

regarding your air monitoring network. The U.S. Environmental Protection Agency (EPA) has 

completed its review of the TCEQ's 2015 Annual Monitoring Network Plan to ensure it meets the 

requirements of 40 Code of Federal Regulations (CFR) Part 58 that are under the oversight of the 

Regional Administrator. At EPA Region 6, approval authority for annual monitoring network plans is 

delegated to the Associate Director for Air Programs. 

We appreciate your cooperation and work to submit your 2015 network plan. The network assessment 

process presents an opportunity for the EPA Region 6 and the TCEQ to collaborate on the air 

monitoring network design. See 40 CFR Part 58 Appendix D, Section 1.1.2. I am pleased to inform you 

that your 2015 ambient air monitoring network plan is approved in accordance with 40 CFR §58.1 0. 

Also, as requested in your Five Year Ambient Monitoring Network Assessment, your requests to renew 

lead waivers for the Lower Colorado River Authority Fayette Power Plant in Fayette County and the 

United States Department of the Army Fort Hood facility near Killeen are approved. We note an area in 

your PM network requiring immediate attention: the need for a continuous PM2.s monitor in Texarkana. 

Details of our review of your air monitoring network plan are provided in the enclosure. 

The EPA appreciates the TCEQ's use of the revised Metropolitan Statistical Area definitions and 2014 

population estimates from the U.S. Census Bureau. We look forward to our continued collaborative 

work with the TCEQ on your 2016 ambient air monitoring network plan. If you have any questions, or if 

you would like to discuss our comments, please contact me at (214) 665-7 548, or your staff may contact 

Ms. Frances Verhalen, Air Quality Analysis Section Chief, at (214) 665-2172. 

Enclosure 

Since/§' .4 ///' ' ~ ~y//4- kHansen Associate Director for 

Air Programs 

lntemet Address (URL) • http://www.epa.gov/region6 

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Texas Commission on Environmental Quality 

2015 Annual Ambient Air Monitoring Network Plan Technical Comments 

The 2015 Texas Annual Monitoring Network Plan (AMNP), dated June 30, 2015, was received on 

July 1, 2015. This plan will be referred to as the "2015 Plan" throughout the remainder of this document. 

In accordance with the requirements of 40 Code of Federal Regulations (CFR) Part 58 and its 

appendices, the U.S. Environmental Protection Agency (EPA) bas reviewed the 2015 Plan and our 

comments are provided below. The comments below reflect the EPA's efforts in collaboration with the 

Texas Commission on Environmental Quality (TCEQ) to maintain an accurate and efficient ambient air 

monitoring network. 

General Comments 

We appreciate the TCEQ's annual air monitoring network review for 2015, and acknowledge the 

TCEQ's finding that "After consideration ofthe federal regulations, 2014 U.S. Census Bureau 

population data, and 20 15 design values, the TCEQ will meet or exceed all monitoring requirements 

with the above mentioned recommendations for next year." We note that in order to meet federal 

monitoring requirements, there is a need for a continuous PM2.s monitor in Texarkana. This is discussed 

further in the section "Particulate Matter (PM) Monitoring" below. We request that the TCEQ continue 

to include an assessment of its plan's conformance with 40 CFR58 and its appendices in next year's 

review, and references to the CFR for network changes. 

For future plans, at the time the proposal becomes available for public review, we request that a web link 

to the annual monitoring network proposal be provided to Ms. Frances Verhalen at 

verhalen.frances@epa.gov and Ms. Ellen Belk at belk.ellen@epa.gov. 

Also, we appreciate that the TCEQ has been providing an electronic version of the AMNP and 

encourage you to continue to provide an electronic version in addition to the hardcopy. For future plans, 

we ask that the TCEQ also provide an Excel spreadsheet of its site list, which for the 2015 Plan was 

provided in Appendix A: TCEQ SLAMS, PAMS, NATTS, NCore, and SPM Site List. Electronic copies 

may be sent to Ms. Frances Verhalen and Ms. Ellen Belk at the email addresses above. 

Nitrogen Dioxide (N02) Monitoring 

Area-wide N02 Monitors 

The EPA Region 6 acknowledges that the N02 area-wide monitors for the Houston-The WoodlandsSugarland [Clinton, Air Quality System (AQS) #48-201-1 035], Dallas-Fort Worth-Arlington (Hinton, 

AQS Site ID: 48-113-0069), San Antonio-New Braunfels (Northwest, AQS Site ID: 48-029-0032), and 

Austin-Round Rock (Northwest, AQS Site ID: 48-453-0014) core-based statistical areas, as required by 

the 40 CFR, Part 58, Appendix D, Section 4.3.3, were approved in the 2013 AMNP response letter from 

EPA Region 6 dated May 28, 2014. 

Regional Administrator Required Monitoring (RA40) Monitors 

The EPA Region 6 acknowledges that the N02 monitors (i.e. El Paso Ascarate, AQS Site ID: 
48-141-0055, Houston Clinton, AQS Site ID: 48-201-1035, Arlington Municipal Airport, AQS Site ID: 

48-439-3011 and Beaumont Nederland High School, AQS Site ID: 48-245-1 035) for use to help protect 

susceptible and vulnerable populations under the "RA40" national requirement (40 CFR Part 58, 

Appendix D, Section 4.3.4) were approved in the 2013 AMNP response letter from EPA Region 6 dated 

May 28, 2014. 

Near-Road Monitoring Sites 

In an email dated December 3, 2014, the EPA Region 6 approved the phase II near-road site locations 

for Dallas-Fort Worth (i.e. the Fort Worth California Parkway North site, AQS Site ID: 48-439-1 053) 

and for Houston (i.e. the Houston North Loop site, AQS Site ID: 48-201-1052). Both sites were 

deployed in 2015 as required by 40 CFR Part 58, Appendix D, Section 4.3.2. We acknowledge that the 

Fort Worth California Parkway North and Houston North Loop sites also house, in addition to the 

required N02 monitors, required PM2.s and CO monitors in accordance with 40 CFR Part 58, Appendix 

D, Sections 4.7 and 4.2.1. Additional PM2.s and CO monitors will be required to be deployed by 

January 1, 2017, at the existing near-road sites in Austin and San Antonio. 

Sulfur Dioxide (S02) Monitoring 

The TCEQ operates 25 S02 monitors, 3 of which are at National Core multipollutant monitoring station 

sites. No additional monitors are required according to the S02 Population Weighted Emission Index. 

The TCEQ is meeting the network design requirements for ambient air quality monitoring for S02. See 

40 CFR Part 58, Appendix D Section 4.4. 

Lead (Pb) Monitoring 

Pb Waivers 

The TCEQ has submitted five Pb waivers for source-oriented monitoring since 2010, and all have been 

granted by EPA Region 6. Three of these waivers are no longer required because source emissions have 

decreased below the 0.50 tons per year threshold. 

Requests to renew Pb waivers for the Lower Colorado River Authority (LCRA) Fayette Power Plant in 

Fayette County, Texas, and the United States Department of the Army Fort Hood facility near Killeen 

were included in the TCEQ's Five Year Network Assessment, submitted to EPA Region 6 on 

June 30, 2015. Based on the data and modeling discussion provided by TCEQ in Appendix E of the Five 

Year Network Assessment, these Pb waiver renewal requests are approved. For the LCRA facility, the 

sources were modeled in 2009; since then there have been no changes to the modeled source parameters 

and the reported emissions were lower in 2013 than in 2009, which would correspond with lower 

predicted Pb concentrations than previously modeled. For the Fort Hood facility, the sources were 

modeled in 2012; since that time there have been no changes to the modeled source parameters and the 

2015 permit allowable emission rates were shown to correspond with a maximum predicted modeled 

concentration of less than half the Pb NAAQS. 

Pb Collocation 

The TCEQ is currently operating thirteen Pb monitoring sites, three of which have collocation. The 

TCEQ is currently exceeding the required number of collocated Pb monitors as detailed in 40 CFR 

Part 58, Appendix A, Section 3.3.4.3. With collocation at the Frisco Eubanks site (AQS Site ID: 

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48-085-0009), the requirement for collocation at the highest concentration site is currently being met. 

Because the design value (DV) of this site is expected to drop dramatically in 2016, please ensure the 

collocation requirements continue to be met. 

Ozone (03) Monitoring 

The EPA Region 6 acknowledges that no changes occurred in the Texas ozone monitoring network in 

2015 . 

Carbon Monoxide (CO) Monitoring 

EPA Region 6 acknowledges the following end dates in AQS for the nine CO monitors approved for 

discontinuation in the 2013 AMNP response letter from the EPA Region 6 dated May 28, 2014. 

According to AQS, the end date for CO monitoring was June 30, 2014, for the Houston Aldine site 

(AQS Site ID: 48-201-0024), the Arlington Municipal Airport site (AQS Site 10: 48-439-3011), and the 

Austin Northwest site (AQS Site ID: 48-453-0014). Also in AQS, the end date for CO monitoring was 

December 31 , 2014, for the El Paso UTEP site (AQS Site ID: 48-141-003 7), the El Paso Skyline site 

(AQS Site ID: 48-141 -0058), the Houston Lang site (AQS Site ID: 48-201-0047), the Houston Texas 

Avenue site (AQS Site ID: 48-201-0075), and the Houston Park Place site (AQS Site ID: 48-201-0416). 

The Fort Worth Northwest site (AQS Site ID: 48-439-1 002) has an end date in AQS of 

October 31,2014. 

Particulate Matter (PM) Monitoring 

Particulate Matter of 10 Microns or More (PM10) 

EPA Region 6 notes that in the letter responding to your 2014 Plan (dated January 14, 20 15), the EPA 

approved the proposal to deploy the required State or local air monitoring stations PMto monitor at the 

Brownsville (AQS Site 10: 48-061-0006) site in the Brownsville-Harlingen Metropolitan Statistical 

Area (MSA) and at the Edinburg East Freddy Gonzalez Drive (AQS Site ID: 48-215-1046) site in the 

McAllen-Edinburg-Mission MSA as meeting the requirements of 40 CFR Part 58, Appendix D, Section 

4.6. Please notify EPA Region 6 which PM to monitoring method is used at these sites and when the 

monitors were deployed and became operational. Please ensure this information is reflected in the 

TCEQ's 2016 AMNP. 

EPA Region 6 acknowledges that the following PM to monitors were replaced with PM10 method 062 

monitors as noted in AQS: Socorro Hueco (AQS #48-141-0057) primary and collocated QA samplers 

and Laredo Vidaurri (AQS# 48-479-0016) primary and collocated QA samplers. · 

For the Tyler MSA, the table in Appendix H indicates that there are 0 required PM10 monitors and 

1 existing monitor. The EPA agrees that no PM10 monitors are required in the area but notes a 

discrepancy with Appendix A, which does not list any PM to monitors in the Tyler area. Please verify the 

number of existing PM10 monitors, and update Appendix A or Appendix H as appropriate. 

PM10 Collocation 

Based on review of the number of collocated PM to monitors, the EPA clarified that collocation is 

required for 15% ofthe entire manual network. Based on the current network of27 monitors, the TCEQ 

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is required to have 4 collocated monitors and currently operates 8. The EPA is open to discussions or 

proposals for reducing the number of collocated monitors. 

Particulate Matter of 2.5 Microns or Less (PMz.s) 

In the El Paso MSA, the table in Appendix I indicates that there are 3 required monitors and 2 existing 

monitors. Population and design value requirements would support a finding that 2 National Ambient 

Air Quality Standard PM2.s monitors are needed in the El Paso area. Please verify the number of 

required and existing PM2.s monitors, and update Appendix I as appropriate. 

In the 2014 AMNP, the TCEQ proposed to operate the Brownsville PM2.s monitor on a 116 schedule. 

The EPA did not approve of this schedule due to lack of current data and the TCEQ agreed in the 

response letter, dated April 7, 2015, to operate this monitor on a 1/3 schedule. Examination ofthe data 

indicates that this monitor is running on a 1/3 schedule but in Appendix A the operating schedule is 

listed as 1/6. Please verify the operating schedule of this monitor. After TCEQ has submitted their PM2.s 

network evaluation, including the PM2.s tapered element oscillating microbalance (TEOM) network, as 

part of the 20 15 TCEQ Five Year Network Assessment, changes in the sampling schedule of these 

monitors can be requested after consideration of factors including, but not limited to, the historical PM2.s 

data quality assessments, the location of current PM2.s DV sites, and their regulatory data needs as 

provided by 40 CFR §58.12(d)(l)(ii). · 

PMz.s Collocation 

The TCEQ deployed 4 new Phll.s Federal reference method (FRM) monitors which increases the 

number of monitors to 25: Fort Worth California Parkway North (AQS 484391053), Houston North 

Loop (AQS 4820 11052), Edinburg East Freddy Gonzalez Drive (AQS 482151046), and Brownsville 

(AQS 480610006) using sampling method 145. According to 40 CFR Part 58, Appendix A, Section 

3.2.5, 15% ofthe primary monitors for each sampling method are required to be collocated. The TCEQ 

currently has three collocated monitors to meet the 15% collocation requirements for method 145. 

These monitors are at the following sites: the Dallas Hinton site (AQS #48-113-0069), the Houston 

Clinton site (AQS #48-201-1035) and the Corpus Christi Huisache site (AQS #48-355-0032). However, 

the addition of the PM2.s FRM sites proposed for deployment in the Brownville-Harlingen and the 

McAllen-Edinburg-Mission MSAs and the two near-road PM2.s monitors now require the TCEQ to have 

an additional collocated monitor. The EPA concurs with the TCEQ recommendation of the addition of a 

PM2.s FRM gravimetric sampler to the El Paso Chamizal (AQS 48-141-0044) site to meet the 

collocation requirement. 

PMz.s Continuous Network 

For the Texarkana MSA, according to 40 CFR Part 58, Appendix D, Section 4.7.2, the TCEQ is required 

to operate continuous PM2.s monitors equal to at least one-half the minimum required sites listed in 

Table D-5 of 40 CFR Part 58, Appendix D. Since the TCEQ operates a SLAMS PM2.s FRM at the 

Texarkana site (AQS #48-037-0004), the TCEQ is also required to operate a continuous monitor within 

the Texarkana MSA. We understand that the TCEQ is unable to deploy a TEOM monitor at the 

Texarkana site (AQS #48-037-0004) due to logistical issues. Based on a conversation between Frances 

Verhalen and Patti de Ia Cruz on October 5, 2015, we understand that the TCEQ plans to relocate the 

monitoring station in fiscal year 2016 and install a continuous PM2.s monitor by December 31, 2015. 

Please notify EPA Region 6 where the TCEQ is planning to locate the PM2.s continuous monitor and 

which method will be used. Once EPA Region 6 has approved the site location and method in 

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accordance with 40 CFR Part 58 and its appendices, the TCEQ will need to notify EPA Region 6 when 

the monitor is deployed and operational. Please ensure that this change is reflected in the TCEQ's 2016 

AMNP and also in AQS. 

In accordance with 40 CFR Part 58, Appendix D, Section 4.7, during the transition to the new site 

we request that the TCEQ continue to operate the PM2.s FRM monitor at the Texarkana site (AQS 

#48-037-0004), which will continue to sample once every third day, for continuity of data. 

The TCEQ is also required to operate PM2.s monitors for the Air Quality Index system for any MSA 

with a population exceeding 350;000. See 40 CFR §58.50(b). The TCEQ's continuous PM2.s network 

currently meets, and in some cases, exceeds this requirement. We suggest the TCEQ reassess their 

continuous PM2.s network for efficiency and coverage. Further discussion will be needed before changes 

are made to the TCEQ continuous PM2.s network. 

We note that the PM2.s TEOM at the Wichita Falls site (AQS #48-485-0315) was approved for 

discontinuation in an email to the TCEQ on March 31, 2014, and acknowledge the end date of 

February 24,2015, as provided in your letter dated April 7, 2015. 

In the Laredo MSA, the table in Appendix I indicates that there are 0 required monitors and 2 existing 

monitors. The EPA agrees that no continuous PM2.s monitors are required in the area but notes a 

discrepancy with Appendix A, which lists only 1 continuous PM2.s monitor in the Laredo area. Please 

verify the number of existing PM2.s monitors, and update Appendix A or Appendix I as appropriate. 

Volatile Organic Compounds (VOCs), Carbonyls and Meteorology 

The EPA Region 6 acknowledges that no changes occurred in the TCEQ Automated Gas 

Chromatograph (Auto-GC), canister, carbonyl and meteorology networks in 2015. 

Photochemical Assessment Monitoring Stations (P AMS) 

In Appendix A there are some Photochemical Air Monitoring Station (P AMS) meteorological 

parameters that need to be changed from Special purpose monitor (SPM) to P AMS under the column 

titled "AQS Network & Monitor Type". 

Please make the following changes in Appendix A and the AQS for the following four monitors: 

1. Relative Humidity needs to be changed from SPM to PAMS at the Dallas Hinton site (AQS Site 

ID: 48-113-0069) 

2. UV Radiation needs to be changed from SPM to P AMS at the El Paso UTEP site (AQS Site ID: 

48-141-0037) 

3. Solar Radiation needs to be changed from SPM toP AMS at the El Paso Chamizal site (AQS Site 

ID: 48-141-0044) 

4. Relative Humidity needs to be changed from SPM to PAMS at the Houston Aldine site (AQS 

Site ID: 48-201-0024). 

The following changes to the P AMS network were approved by the EPA by letter dated 

January 29, 2015: 

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• The decommissioning of the Reactive Oxides of Nitrogen (NOx) monitor at the SETRPC 4 0 

Sabine Pass site (AQS Site ID: 48-245-0101 ). 

• There-designation of the carbonyl monitors at the Fort Worth Northwest site (AQS Site ID: 48-

439-1002) and the El Paso Ascarate Park SE site (AQS Site ID: 48-141-0055) from PAMS to 

SPM. 

• There-designation of the radar profiler at the EJ Paso UTEP site (AQS Site ID: 48-141-0037) 

from PAMS to SPM. 

The EPA previously concurred with there-designation of the dew point monitors to SPMs in the 2013 

AMNP response letter from EPA dated May 28,2014. We appreciate the TCEQ updating AQS with 

these SPM designations beginning with a start date of July 1, 2014. 

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