��TCEQ – (APGG D874vD, Revised 0) Modeling and Effects - PDF document

��TCEQ – (APGG D874vD, R
��TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage Air Perµit Reviewer Reference GuideAPGG D874Modeling and Effects Review Applicability (MERA) Air Perµits Givision Texas Coµµission on Environµental Quality March 2018 ��TCEQ – (APGG D874vD, Revised 03) Modeling and Effects Review ApplicabilityPage Table of ContentsIntroduction 1Suµµary of Significant Changes 2How to Geterµine the Scope of Modeling and Effects Review for Air Perµits 3Step 0: Applicability and Procedures 3Step 1: No Net Increase DStep 2: Ge Miniµis Increase DStep 3: 10% of ESI Evaluation 6Step 4: Projectwide Modeling 8Step D: MSS Evaluation 9Step 6: Ratio TestStep 7: Sitewide Modeling.Step 8: GocuµentationAppendix A: GlossaryAppendix B: Toxicology Eµissions Screening IistAppendix C: Screening TablesAppendix G: Toxicology Effects Evaluation ProcedureAppendix E: MERA Flowchart�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.95; 3;.01; 55;.08;&#x 46.;≈&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.95; 3;.01; 55;.08;&#x 46.;≈&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 1 of IntroductionThe Texas Coµµission on Environµental Quality (TCEQ) regulates air quality in the state of Texas through the Texas Clean Air Act (TCAA), located in Chapter 382 of the Texas Health and Safety Code and rules, including those in Title 30 Texas Adµinistrative Code (TAC)Chapter116.The TCEQ staff conducts a preconstruction technical review during the air perµitting process. This review ensures that the operation of a proposed facility will coµply with all the rules of the TCEQ and intent of the TCAA, and not cause or contribute to a condition of air pollution. A review of an air perµit application involves an assessµent of huµan health and welfare effects related to eµissions froµ production and planned µaintenance, startup, and shutdown (MSS) activities.The huµan health and welfare effects are evaluated for applications withnew andCor µodified sources of aircontaµinants, as well as in perµitting actions involving retrospective reviews or previously unevaluated eµissions. Contaµinants for which stateair quality standardsor National Aµbient Air Quality Standards (NAAQS) exist are evaluated using a coµparison between predicted concentrations and the standards.The evaluation procedures for these contaµinants are covered in detail in the TCEQ Air Quality Modeling Guidelines – APGG 6232If there are no state or national aµbient air quality standards for a contaµinantit is evaluated through the TCEQ’s Modeling and Effects Review Applicability (MERA) process. Guring the course of the MERA process, the scope of air dispersion µodeling and effects review is deterµined.While thisdocuµent provides a general process and defines µiniµuµ considerations for agency staff’s air quality iµpacts analysis, this docuµent is not regulatory and does not liµit the perµit reviewer’s ability to require the applicant to provide additional inforµation. In addition, the perµit reviewer and Air Perµits Givision () µanageµent have the discretion to perforµ an effects review outside of the MERA process.The MERA process begins with Step 0, which inforµs the user of the general procedures and practices to be followthroughout the MERA process. Steps 1 through 7 detail the criteria used to evaluate the health effects of an air contaµinant. The initial steps in the MERA process are designed to be siµple and conservative. As one progresses through the process, the steps require µoredetail and result in a µore refined (less conservative) analysisSitewide air dispersion µodelingis conducted at Step 7e results are evaluated usingthe Toxicology Effects Evaluation Procedure in Appendix G. If a contaµinantevaluated on a cheµical species by cheµical species basis, µeets the criteria of a step, the review of huµan health and welfare effects is coµpl

ete. A cheµical species is said to “f
ete. A cheµical species is said to “fall out” of the MERA process at this step, and the MERA docuµent will direct the user to Step to docuµent the evaluation. If a contaµinant does not µeet the criteriaof a step, the docuµent will direct the user to theappropriate next step. It is acceptable toskip stepsthe MERA process and proceed directly to µore detailed steps.This docuµent replaces Modeling and Effects Review Applicability, APGG D874, July 2009.�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 2 of Suµµary of Significant ChangesRevision GateGescription of ChangesFebruary 2018Iµprove ease of use and clarity, reµoved infrequently used steps,revised µultipoint equation in previous Step D.Cheµical species for which there is not an ESI µay be exeµpted froµ a MERA evaluation.July 2009Provided additional clarity pertaining to unevaluated and MSS eµissionsand added Appendix G, Toxicology Effects Evaluation Procedure.August 2008Updated requireµents for APWI Constituents, added criteria for planned MSS and unevaluated eµissions and added the terµ “perµitwide,” established µagnitude and frequency criteria for planned MSS eµissions.October 2001Reµoved special interest constituents, and replaced with Air Pollutant Watch Iist, corrected µultipoint equation in Step D, and added inforµation about single property line designations.August 1998Updated flowchart, added requireµents for constituents of special interest, and added effects evaluation procedures and updated the forµat.July 1993Original MERA Guidance Gocuµent�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 3 of How to Geterµine the Scope of Modeling and Effects Review for Air PerµitsStep 0: Applicability and ProceduresMERA Evaluation ApplicabilityA MERA evaluation µust be conducted for all cheµical species whose shortterµ or longterµ allowable eµission rate will increase froµ any eµission point nuµber (EPN) throughthe project. The change in an allowable eµission rate is calculated as the difference between the proposed µaxiµuµ allowable eµission rate and the currently perµitted µaxiµuµ allowable eµission rate. Throughout the reµainder of this docuµent “allowable eµission rates” will be referred to as eµission rates” or “eµissions.”The followingare exeµpt froµ a MERA evaluation: All cheµical species for which there is a state air quality standard or NAAQS, other than particulate µatterspeciesthat have an Effects Screening Ievel (ESI) published by the TCEQ Toxicology Givision. The ESI database will reference the NAAQS in place of an ESI if a MERA evaluation is not required for a particulate µatterspecies. The “Air Quality Modeling Guidelines” docuµent (APGG 6232) provides the process for evaluating cheµical species for which there is a state air quality standard or NAAQS.Facilities and cheµical species listed on the Toxicology Eµissions Screening Iist (seeAppendixB).Cheµical species for which there is not a current ESI listed in the Toxicity Factor Gatabase, accessed through the Texas Air Monitoring Inforµation Systeµ (TAMIS) database via the Toxicology ESI suµµary and detail reports. While no effects review is required, such cheµical species µust satisfy the BACT and other requireµents. In addition, the perµit reviewer and APG µanageµent have the discretion to

perforµ an effects review outside of t
perforµ an effects review outside of the MERA process.This exeµption does not apply to cheµical species being authorized under cheµical flexibility perµit provisions. General ProceduresThe following appliesto the health effects review described in the MERAprocess, unless otherwise specified:The MERA evaluation µust be conducted for each cheµical species individually(except in cases where the Toxicology Givision has developed an ESI for a blend such as gasoline), and µust include all EPNs in the project with an increasing allowable eµission rate of that cheµical species.A shortterµ iµpacts evaluation µust be conducted for all cheµical species with an increase in shortterµ eµissions. A longterµ iµpacts evaluation µust be conducted for cheµical species with an increase in longterµ eµissions under the following conditions:for all cheµical species with a longterµ ESI that is less than 10 percent of the shortterµ ESI ; if a cheµical species does not have an assigned shortterµ ESI, but does have an assigned longterµ ESI; or �� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 4 of if previous iµpacts were approved based on a liµited frequency of exceedances.For other cases, a longterµ iµpacts is not required unless requested by the perµit reviewer. The input of a screening µodel is an eµission rate in µass per unit of tiµe and the output is a µaxiµuµ 1-hr ground level concentration(GICµax), in units of µicrograµs per cubic µeter (µgCµ3). Therefore, if a longterµ iµpacts evaluation is necessary and screen µodeling is used, an annual GICµaxµust be calculated by µultiplying: an annual unit iµpact µultiplier, an eµission rate representative of the annual eµission ncreaseassociated ith the 1-hr GICµax. For SCREEN3, the annual unit iµpact µultiplier is deterµined by µultiplying the hourly unit iµpact µultiplier by 0.08, which is an annual conversion factor that accounts for the variation in µeteorological conditions throughout the year. For AERSCREEN the annual unit iµpact µultiplier is deterµined by µultiplying the hourly unit iµpact µultiplier by the annual conversion factor 0.1. An annual conversion factor is not needed if a refined µodel that can calculate an annual GICµaxis used. To deterµine the eµission rate representative of the annual eµissions increase, convert the tonperyear increase in eµissions to a poundhour rate using 8760 hours per year and 2000 pounds per ton. As an exaµple, an eµission source has an hourly unit iµpact µultiplier of 100 µgCµ, generated using SCREEN3,and an annual eµission rate of 40 tpy. The annual eµission rate is converted to an hourly rate as shown below:40 tpy x 2000 lbCton C 8760 hoursCyear = 9.134 lbChrThe µaxiµuµ 1hr ground level concentration is µultiplied by 0.08 yield an annual unit iµpact µultiplier: 100 µgCµx 0.08 = 8 µgCµThe annual GICµaxis then calculated by µultiplying that annual unit iµpact µultiplier and that eµission rate representative of the annual eµissions:µgCµx 9.134 pph = 73.1 µgCµESIs should be deterµined froµ the Toxicity Factor Gatabase, accessed through the TAMISdatabase. Instructions for using the database can be found on the Toxicology Givision’s website. If a cheµical species doesnot have an assigned , itµay be exeµpted froµ a MERA effects evaluation,unless an evaluation is requested by the perµit reviewer. However, for certain cheµical species, such as cheµicals to be approved under cheµical flexibility perµit provisions or roprietary µixtures, a new ESIµaybe requested froµ the Toxicology Givision. In addition, a default ESI of 2 µgCµµay be used for a species with an unknown ESI.Unless otherwise stated, each step in theMERA evaluation µust include all eµissions

associated with the project, including:
associated with the project, including: MSS eµissions that will be authorizedunder PerµitBy Rule (PBRs). Eµissions froµ PBRs and Standard Perµits (SPs) that are beingconsolidatedby incorporation into the perµit.�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage D of Cheµical species on the Air Pollutant Watch Iist (APWI) are subject to the requireµents detailed in the “Perµit Application Guidance for Coµpanies Iocated in an Air Pollutant Watch Iist Area” guidance docuµent, and µust also be evaluated usingthe MERA. Also, a casecase analysis not relying on the steps of the MERA µay be required for any specific situation as deeµed appropriate by the perµit reviewer and APG µanageµent. A retrospective MERA evaluation µay be required for correctionsin representations or eµission calculationsThis deterµination will be µade on a casecase basis. All refined µodeling should be conducted in accordance with direction froµ APG staff and the “Air Quality Modeling Guidelines” docuµent (APGG 6232).A pre-µodeling µeeting or teleconference with the applicant, perµit reviewer and µodeling teaµ is recoµµended before refined µodeling is perforµed.Step 1: No Net IncreaseSuµ the proposed eµission increases and decreases froµ each EPN to deterµine the net change in eµissions.Step 1: Is the net change in eµissions less than or equal to zero?If “Yes” Conduct a qualitative analysis to deterµine if the project will result in an increase in the GICµaxat the propertyline. The qualitative analysis should include factors affecting the GICµaxsuch as distance froµ the property line and the type of source (point, area, or voluµe). ubµit the analysis as requested bythe perµit reviewer. Goes the qualitative analysis indicate that the GICµaxwill increase?If “No” The MERA is coµplete. Proceed to Step 8 for docuµentation.If “Yes” Step 2. If “No” →Step 2Step 2: Ge Miniµis IncreaseSuµ the shortterµeµissionincreases froµ each EPN to obtain the total shortterµ project increase. Go not include eµission rate decreasesfroµ any EPNInclude any unevaluated eµissions such as eµissions froµ PBRs, SPs, or any other authorization.If MSS and production eµissions occur siµultaneously, the MSS and production eµissionsinto one eµission rate. Otherwise, calculate separate rates. Step 2: Is the longterµ ESI ≥ 10 % of the shortterµ ESI? Are total shortterµ project increases less thanthe appropriatede µiniµis levelsbelow? If MSS and production eµissions occur siµultaneously, evaluate the coµbined eµission rates against the production de µiniµis levels. Otherwise, evaluate MSS and production eµissions separately against their respective de µiniµis levels. �� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 6 of Shortterµ ESI(μgCµProduction Eµissions Increase (lbChr)MSS Eµissions Increase(lbChr)2 ≤ESI < D00≤ 0.040.1D00 ≤ ESI < 3D00≤ 0.13D00 ≤ ESI ≤ 0.40.4If “Yes” The MERA is coµplete. Proceed to Step 8 for docuµentationIf “No” →Step 3. Step 3: 10% of ESI EvaluationEvaluate eµission increases in this tep. Go not include eµission decreases.For each EPN (EPN), obtain the unit iµpact µultiplier (X), using either the Screening Tables found in Appendix C or an approved EPA µodel.Use the following equation to conservatively predic

tiµpacts froµ the project:�
tiµpacts froµ the project:������ = �=1here:GICµax= The µaxiµuµ offproperty ground level concentration for the appropriate averaging tiµe of the cheµical species eµitted froµ all eµission points in the iµpacts evaluation, in µgCµ. The unit iµpact µultiplier obtained froµ the Screening Tables in Appendix C or an approved EPA Model for EPN, in µgCµper lbChr.Theprojecteµissionrate increase of the cheµical species being evaluated, froµ EPNin lbChr.n = The total nuµber of eµission points. Step 3: Is the following inequality true?������≤��∗here:= The effects screening level for the appropriate averaging tiµe, in gCµfor the cheµical species being evaluated. If “Yes” Step 8. The MERA is coµplete. If “No” → Step 4. �� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 7 of Exaµple:Eµission Rate Increase (lbChr)gCµGistance(feet)Height(feet)X ValuegCµC lbChr)20,00020,000�=10.10.1252µ�ℎ�ℎ�50µ�ℎ�10ℎ��≤0.120000µ�756µ�500µ�000µ�256µ�000µ�In this exaµple, the cheµical species evaluated fallout at Step 3 because the increase in total ground level concentration is less than 10% of the ESI.�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 8 of Step 4ProjectwideModelingModelthe MSS and production eµissionfor the project. Geterµine a GICµaxfor production eµissions and a GICµaxfor MSS eµissions.Modelthe MSS and production eµissions for the project coµbined with all new and increaseeµissions since the µost recent sitewide µodeling. Geterµine a GICµaxfor production eµissions and a GICµaxfor MSS eµissions.Go not include eµission decreases.Historical µodeling records µay be used to deterµine GICµaxvalues for this step.Step : Will the following thresholds be µet at the location of the GICµax? Planned MSS OnlyProduction OnlyGICµax≤D0% ESI for the project and all new and increased planned MSS eµissions since the µost recent sitewide µodelingANGGICµax≤2D% ESI for the projectGICµax≤2D% ESI for the project and allnew and increased production eµissions since the µost recent sitewide µodelingANGGICµax≤10% ESI for the projectIf “Yes” for both Production and Planned MSS Step 8. The MERA is coµplete.If “Yes” for Production and “No” for Planned MSSThe MERA is coµplete for production eµissions. MSS eµission µust be evaluated inStep . If “No” for ProductionStep 6. �� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD,

Revised 0) Modeling and Effects Review
Revised 0) Modeling and Effects Review ApplicabilityPage 9 of Step D: MSSEvaluationStep DA: Is the cheµical species one of thefollowing?AcroleinAcrylonitrileBenzeneBroµine1,3butadieneCarbon disulfideChlorineChloroforµEpichlorohydrinFluorineForµaldehydeHydrochloric acid (HC)Hydrofluoric acid (HF)HydrazineMercaptansMethyl broµideMethylenediphenyl diisocyanate(MGI)PhosgenePhosphineStyrene (odor)Toluene diisocyanate (TGI)Any cheµical species with a shortterµESI <2 µgCµIf “Yes” → Step 6.If “No” →Step DB.Step DBWill the plannedMSS eµissions µeet all of the following thresholdsfor the corresponding coluµn as shown belowGround Ievel Concentration (µgCµExceedances per Year (GICµax≥ 1 × ESIλ ≤ 24GICµax≥ 2 × ESIλ ≤ 12GICµax≥ 4 × ESIλ ≤ 6GICµax≥ 10 × ESIλ =GICµax> 20 × ESIλ = 0If “Yes” → The MERA is coµpletefor the MSS eµissions. If “No” →Step 6. �� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 10of Step 6: Ratio TestSuµ the eµission increases froµ the project to obtain the total project increase, including planned MSS and production increases. Go not include any eµission decreases.Suµ the currently authorized eµissions and all previously unevaluated eµission froµ all eµission points on the site, along with the new and increased eµissions froµ the project to obtain the proposed sitewide eµissions.Step 6: Is the following inequality true? ���where:GICµax = The µaxiµuµ ground level concentration for the appropriate averaging tiµe, in µgCµ. ESI = The effects screening level for the appropriate averaging tiµe, in gCµ. The project increase, in lbChr ortpy. = The proposed sitewide eµissions, in lbChr or tpy.If “No” Step 7.If “Yes” Step 8. The MERA is coµplete.Step : Sitewide odeling.Conduct sitewide µodeling in accordance with AGMT guidance; Update sitewide µodeling froµ a recently approved project to include the project increase and any previously unevaluated eµissions;Subµit µonitoring data per AGMT guidance and deµonstrate that the µonitoring data are representative of near worstcase iµpacts and should be used instead of sitewide µodeling. Contact the perµit reviewer to arrange a µeeting to discuss currently available µonitoring data or to receive guidance forand approval of, a strategy to collect µonitoring data.Sitewide µodeling applies to eµissions froµ all eµission points on propertiesidentified in single propertyline designations between µultiple owners.TCEQ staff will evaluate the µodeling analysis to deterµine if it is appropriate to proceed to Step 8. Step : GocuµentationGocuµent the MERA evaluationand provide all supporting inforµation. The appropriate TCEQ staff will review and evaluate the iµpacts analysis.�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 11of Appendix AGlossaryPlease note that there are often differences in terµ usage and terµ definitions between the state and federal regulatory agencies. However, when conducting a MERA evaluation with this docuµent, please refer to the following definitions.air contaµinantParticulate µatter, radioactive µaterials, dust fuµes, gas, µist, sµoke, vapor, or odor, including any coµbination of those iteµs, produced by processes other than natu

ral (Texas Health andSafety Code (THSC)
ral (Texas Health andSafety Code (THSC) §382.003). ir dispersion µodelµodel ofthe dispersion and transport of contaµinants in the atµosphere, used to estiµate the ground level concentration resulting froµ the eµission of a contaµinant, as further described in the “Air Quality Modeling Guidelines” docuµent (APGG6232).air pollutionThe presence in the atµosphere of one or µore air contaµinants in such concentration and of such duration that are or tend to be injurious to or to adversely affect huµan health or welfare, aniµal life, vegetation, or property, or interfere with the norµal use and enjoyµent of aniµal life, vegetation, or property (THSC §382.003).aµbient aire portion of theatµosphere, external to buildings, to which the general public has access (30 Texas Adµinistrative Code (TAC) § 101.1). For purposes of the MERA, aµbient air is all air outside theproperty line.Air Pollutant Watch Iist (APWI)A list of geographic areas for which aµbient air quality µonitoring data indicates persistent, elevated concentrations of toxic air contaµinants. The list and its accoµpanying prograµs aiµ to reduce eµissions of APWI contaµinants by engaging stakeholders, notifying the public, and requiring additional scrutiny for air perµit applications that propose increases of an APWI contaµinant in an APWI area. This list was established and is µaintained by the TCEQ in coµpliance with the Texas Health and Safety Code, Title D, Subtitle C, Chapter 382. authorizationA µechanisµ to allow the release of eµissions of constituents into aµbient air.Typical authorizations are PBRs, SPs, and casecase NSR Perµits.cheµical speciesAn individual air contaµinant with a specific effects screening level.criteria pollutantA pollutant for which a NAAQS has been defined. µission oint uµber (EPN)A unique identifier for a point of eµission release into the aµbient air.Effects Screening evel (ESI)Screening levels used in TCEQ’s air perµitting process to evaluate the predicted iµpacts of air dispersion µodeling. They are used to evaluate the potential for effects to occur as a result of exposure to concentrations of contaµinants in the air. ESIs are based on data concerning health effects, the potential for odors to be a nuisance, and effects on vegetation. They are not aµbient air standards. If predicted airborne levels of a constituent do not exceed the screening level, adverse health or welfare effects are not expected. If predicted aµbient levels of constituents in air exceed the screening levels, it does not necessarily indicate a probleµ but rather triggers a review in µore depth.facilityA discrete or identifiable structure, device, iteµ, equipµent, or enclosure that constitutes or contains a stationary source, including appurtenances other than eµission control equipµent. A µine, quarry, well test, or road is not considered to be a facility (THSC§382.003 and 30 TAC §116.10).�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 12of round evel oncentration (GICThe ground level concentration f a constituent in µicrograµs per cubic µeter (µgCµ3) as predicted by µodeling or µeasured by µonitoring.GICµaxMaxiµuµ offproperty ground level concentration for the appropriate averaging tiµe of the cheµical species eµitted froµ all eµission points in the iµpacts evaluation, in µgCµGICniMaxiµuµ nonindustrial offproperty ground level concentration for the appropriate averaging tiµe of the cheµical species eµitted froµ all eµission points in the iµpacts evaluation, in µgCµ. longterµAn annual averaging period.National Aµbient Air Quality Standards (NAAQS)Ievels of air quality to protect the public health and welfare (40 Code of Federal Regulations (CFR)§D0.2). Priµary standards are set to pr

otect public health, including the healt
otect public health, including the health of “sensitive” populations such as asthµatics, children, and the elderly froµ the effects of “criteria air pollutants” and certain noncriteria pollutants. Secondary standards are set to protect public welfare, including protection against decreased visibility, daµage to aniµals, crops, vegetation, and buildings.industrial receptorA receptor type such as residential, recreational, coµµercial, business, agricultural, or a school, hospital, daycare center, or church. In addition, receptors in zoned or undeveloped areas are considered nonindustrial. A receptor is a location where the public could be exposed to an air constituent in the aµbient air.refined µodelingAn air dispersion µodel with refined input paraµeters including hourly µeteorological data, µultiple facilities, and facility locations. Ground level concentrations are deterµined across a receptor grid and are µore representative of actual concentrations than those obtained froµ screen µodeling.screen µodelingA siµple air dispersion µodel with liµited input paraµeters that yields a conservative estiµate of the ground level concentration for a single facilityas a function of distance froµ the facility. short terµA onehour averaging period.siteThe total of all stationary sources located on one or µore contiguous or adjacent properties, which are under coµµon control of the saµe person (or persons under coµµon control) (30 TAC § 122.10). sitewide µodelingModeling (refined or screening) of eµissions froµ all eµission points and areas on a contiguous property or at a site. Sitewide µodeling includes all sources authorized under 30 TAC Chapters 106 and 116. Note that de µiniµis eµissions under 30 TAC § 116.119 are not included for sitewide µodeling deµonstrations.sourceA point of origin of aircontaµinants, whether privately or publicly owned or operated (30 TAC § 116.10).unit iµpact µultiplier—An EPN specific factor derived by running a dispersion µodel with a unit eµission rate of 1.0 lbChr or 1.0 gCsec. The unit iµpact µultipliercan be µultiplied by the eµission rate to deterµine the ground level concentration resulting froµ those eµissions. �� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 13of Appendix BToxicology Eµissions Screening IistEµissions froµ the following facilities have been reviewed for health effects and are not expected to cause adverse health effects. These do not require additional review through the MERA process. Odor and particulate eµissions froµ agricultural, food processing, or aniµal feeding or handling facilities.Eµissions of particulates froµ abrasive blast cleaning provided they do not contain any of the following:asbestos;µetalsand µetal coµpoundswith an ESI of less than D0 µgCµ3that are in a concentration of greater than .0%; orcrystalline silica at greater than or equal to 1 percent (weight) of the total particulate weight.Eµissions of particulate µatter, except for µetals, µetal coµpounds,silica, froµ controlled surface coating operations. Controlled surface coating operations are those that capture and abate particulate µatter with a water wash or dry filter systeµ (at least 98% reµoval efficiency) and vent through an elevated stack with no obstruction to vertical flow.Eµissions of particulate µatter froµ rock crushers, concrete batch plants and soil stabilization plants.Eµissions froµ boilers, engines, or other coµbustion units fueled only by pipelinequality natural gasas well as eµissions froµ the coµbustion of natural gas in control devices. Eµissions froµ flares, heaters, therµal oxidizers, and other coµbustion devices burning gases only froµ onshore crude oil and natural gas processing plants, with the excep

tion of eµissions froµ glycol dehydrat
tion of eµissions froµ glycol dehydrators and aµine units. Eµissions of volatile organic coµpounds froµ eµergency diesel engines.Eµissions of freons that have ESIs greater than1D,000 µgCµ3 froµ any facility.Eµissions of the following gases, which have been classified as siµple asphyxiatesfroµ any facility.argoncarbon dioxideethaneheliuµhydrogenµethane nitrogenpropanepropylene�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 14of Appendix CScreening TablesThe screening tables are used to deterµine a conservative estiµate of the ground level concentration of a cheµical species froµ an eµission point. These tables provide conservative unit iµpact µultipliers for a particular eµission point based upon the source’s stack height and distance froµ the nearest property line. The following instructions apply to the selection and use of Tables 1 through 4:Utilize linear interpolation between height and distance paraµeters in the tables to deterµinea µore accurate unit iµpact µultiplier, if desired.Extrapolation with heights or distances greater than the values listed in the tables is not allowed.Assuµe that daytiµe hours are between 6 a.µ. and 6p.µ.Geterµine if the source will be downwashed. Gownwash is a terµ used to represent the potential effects of a structure on the dispersion of eµissions froµ a source. If the source is downwashed, use Table 1 or 3; if the source is not downwashed, use Table 2 or 4. A source is downwashed if each of the three conditions below is satisfied.The source is characterized as a point source. Gownwash does not apply to sources characterized as area or voluµe sources.The stack height of the source is less than the good engineering practice stack height (H). Hdefined as the greater of:6D µeters, µeasured froµ the groundlevel elevation at the base of the stack; For stacks in existence on January 12, 1979 and the owner or operator had obtained all applicable perµits or approvals required under 40 CFR parts D1 : = 2.DH here: H = structure height;For all other stacks= H + 1.DIhere: I = the lesser of the structure height or µaxiµuµ projected width (the width as seen froµ the source looking towards the nearest property line) of the structure; andThe structure is sufficiently close to the stack, as defined whenG ≤ DI,where: G = the distance between the structure and the stack.If the source is located near µore than one structure, deterµine downwash applicability with the structure whose diµensions result in the highest GEP stack height. This structure will cause the greatest downwash effects. Gownwash µay be applicable even in cases where the building is not between the source and the nearest property line.�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [2;.65;„ 3;.81; 77;.64;&#x 61.;瑣&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [2;.65;„ 3;.81; 77;.64;&#x 61.;瑣&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised ) Modeling and Effects Review ApplicabilityPage 1Dof Table 1Gownwash for All Hours (gCµper 1 lbChr)Gistance froµ the Property Iine (feet)Stack Height(feet)9.99.38.79.28.47.87.36.89.48.47.66.96.4D.67.16.4D.8D.DD.14.89.17.96.2D.D4.D4.23.78.77.D6.DD.7D.14.D4.13.73.43.2�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [2;.65;„ 3;.81; 77;.64;&#x 61.;瑣&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [2;.65;„ 3;.81; 77;.64;&#x 61.;瑣&#x ]/S;&#xubty;&#xpe /;

oot;r /;&#xType;&#x /Pa;&#xgina;&#xt
oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised ) Modeling and Effects Review ApplicabilityPage 16of Table 2No Gownwash for All Hours (gCµper 1 lbChr)Gistance froµ the Property Iine (feet)Stack Height(feet)9.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.87.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.98.77.97.D6.6D.9D.29.88.D7.46.66.1D.6D.29.38.37.36.DD.7D.24.89.78.67.86.3D.74.69.68.37.16.1D.D4.64.28.98.27.46.86.1D.D4.94.43.98.87.36.2D.7D.34.94.64.23.98.37.26.2D.34.44.23.93.73.D8.47.46.76.1D.D4.94.43.83.42.92.68.37.26.2D.44.64.23.83.D3.22.82.6�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [2;.65;„ 3;.81; 77;.64;&#x 61.;瑣&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [2;.65;„ 3;.81; 77;.64;&#x 61.;瑣&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised ) Modeling and Effects Review ApplicabilityPage 17of Table 3Gownwash for Gaytiµe (gCµper 1 lbChr)Gistance froµ the Property Iine (feet)Stack Height(feet)9.99.38.79.78.37.87.36.89.48.67.46.96.4D.69.38.67.97.36.76.3D.8D.DD.14.89.48.77.46.86.3D.9D.DD.14.84.D4.23.79.39.39.39.38.67.D6.D6.1D.7D.34.94.64.34.13.83.63.43.2�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [2;.65;„ 3;.81; 77;.64;&#x 61.;瑣&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [2;.65;„ 3;.81; 77;.64;&#x 61.;瑣&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised ) Modeling and Effects Review ApplicabilityPage 18of Table 4. No Gownwash for Gaytiµe (gCµper 1 lbChr)Gistance froµ the Property Iine (feet)Stack Height(feet)9.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.98.77.97.D6.6D.9D.29.88.D7.46.66.1D.6D.29.38.37.36.DD.7D.24.89.78.67.87.06.3D.7D.04.69.68.37.16.1D.DD.04.64.28.98.27.46.86.1D.D4.94.43.98.87.36.2D.7D.34.94.64.23.98.37.26.2D.34.44.23.93.73.D9.48.78.07.46.76.1D.D4.94.43.83.42.92.69.D9.D9.39.38.98.47.97.D7.16.66.2D.8D.4D.04.64.23.83.D3.22.82.6�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;
.64;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;
.64;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 03C18) Modeling and Effects Review ApplicabilityPage 19of Appendix GToxicology Effects Evaluation ProcedureA threetiered approach is used to evaluate the health and welfare effects of cheµical species that undergo sitewide µodeling. A GICµax based on the project eµission increase rather than sitewide eµissions cannot be evaluated under these criteria. These tiers should be used to evaluate both shortterµ and longterµ GICµax values. In describing the results of an effects evaluation, the terµs below are used.Acceptable - adverse health or welfare effects would not be expected as a result of exposure to a given constituent concentration.Allowable - the perµit engineer has provided justification to the Toxicology Givision that the predicted GICs are not likely to occur or that they occur in a location where public access is liµited.Tier I: Is the offproperty GICµaxbelow the ESI?If “Yes → the iµpacts are acceptable.If “No” → Tier II.Tier II: Are both of the following c

onditions µet?GICµax≤ 2 × ESI here:
onditions µet?GICµax≤ 2 × ESI here: the GICµaxoccurs on industrial use propertyThe GIC< ESIhere: the GICis thegroundlevel concentration at the µaxiµally affected, offproperty, nonindustrial receptor.If “Yes” → the iµpacts are acceptable.If “No” → Tier IIITier III: The Toxicology Givisionwill conduct a casecase review of the health and welfare effects of the cheµical species to deterµine if the iµpacts are acceptable, unacceptable, or allowable. The Toxicology Givisionµay consider the following factors.Surrounding land useGICµaxand its frequency of exceedanceMagnitude of the GICPotential for public exposureConservatisµ of the approach use to deterµine the GICµaxExisting concentrations of the cheµical speciesBasis of ESI (odor vs. health, degree of confidence, µargin of safety)Acceptable reductions in existing GICsThis inforµation is analyzedby the toxicologist to develop a final deterµination on the likelihood that eµissions will increase the risk of adverse health or welfare effects.�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;
.64;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;
.64;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 03C18) Modeling and Effects Review ApplicabilityPage 20of Appendix E: MERA FlowchartLT ESL of ST ESLANDST emis ≤ de minimis levels? StartStep Applicability troceduresGLCmaxESLNo5AChemical species on list5BMSS GLCmaxThresholdsNoMeet Ratio TestNoStep EndStep DocumentationYesYeswesults reviewed by TCEQ Stafftrod GLCmaxThresholdsMSS GLCmaxThresholdsYesNoYesIf results are allowableor acceptableNoNoYesNoYesbet emis ≤ 0?NoYesYesKeyemisemissionsincrincreaselongtermprodproductionSTshorttermThis flowch is suµµry of he MERA nd is no inended sue for his guidnceSitewide aodeling�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;
.64;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;
.64;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 03C18) Modeling and Effects Review ApplicabilityPage 20of Appendix E: MERA FlowchartLT ESL of ST ESLANDST emis ≤ de minimis levels? StartStep Applicability troceduresGLCmaxESLNo5AChemical species on list5BMSS GLCmaxThresholdsNoMeet Ratio TestNoStep EndStep DocumentationYesYeswesults reviewed by TCEQ Stafftrod GLCmaxThresholdsMSS GLCmaxThresholdsYesNoYesIf results are allowableor acceptableNoNoYesNoYesbet emis ≤ 0?NoYesYesKeyemisemissionsincrincreaselongtermprodproductionSTshorttermThis flowch is suµµry of he MERA nd is no inended sue for his guidnceSitewide aodeling�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;
.64;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;
.64;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 03C18) Modeling and Effects Review ApplicabilityPage 19of Appendix GToxicology Effects Evaluation ProcedureA threetiered approach is used to evaluate the health and welfare effects of cheµical species that undergo sitewide µodeling. A GICµax based on the project eµission increase rather than sitewide eµissions cannot be evaluated under these criteria. These tiers should be used to evaluate both shortterµ and longterµ GICµax values. In describing the results of an effects evaluation, the terµs below are used.Acceptable - adverse health or welfare effects would not be expected as a result of exposure to a given constituent concentration.Allowable - the perµit engineer has provided

justification to the Toxicology Givision
justification to the Toxicology Givision that the predicted GICs are not likely to occur or that they occur in a location where public access is liµited.Tier I: Is the offproperty GICµaxbelow the ESI?If “Yes → the iµpacts are acceptable.If “No” → Tier II.Tier II: Are both of the following conditions µet?GICµax≤ 2 × ESI here: the GICµaxoccurs on industrial use propertyThe GIC< ESIhere: the GICis thegroundlevel concentration at the µaxiµally affected, offproperty, nonindustrial receptor.If “Yes” → the iµpacts are acceptable.If “No” → Tier IIITier III: The Toxicology Givisionwill conduct a casecase review of the health and welfare effects of the cheµical species to deterµine if the iµpacts are acceptable, unacceptable, or allowable. The Toxicology Givisionµay consider the following factors.Surrounding land useGICµaxand its frequency of exceedanceMagnitude of the GICPotential for public exposureConservatisµ of the approach use to deterµine the GICµaxExisting concentrations of the cheµical speciesBasis of ESI (odor vs. health, degree of confidence, µargin of safety)Acceptable reductions in existing GICsThis inforµation is analyzedby the toxicologist to develop a final deterµination on the likelihood that eµissions will increase the risk of adverse health or welfare effects.�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [2;.65;„ 3;.81; 77;.64;&#x 61.;瑣&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [2;.65;„ 3;.81; 77;.64;&#x 61.;瑣&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised ) Modeling and Effects Review ApplicabilityPage 18of Table 4. No Gownwash for Gaytiµe (gCµper 1 lbChr)Gistance froµ the Property Iine (feet)Stack Height(feet)9.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.98.77.97.D6.6D.9D.29.88.D7.46.66.1D.6D.29.38.37.36.DD.7D.24.89.78.67.87.06.3D.7D.04.69.68.37.16.1D.DD.04.64.28.98.27.46.86.1D.D4.94.43.98.87.36.2D.7D.34.94.64.23.98.37.26.2D.34.44.23.93.73.D9.48.78.07.46.76.1D.D4.94.43.83.42.92.69.D9.D9.39.38.98.47.97.D7.16.66.2D.8D.4D.04.64.23.83.D3.22.82.6�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [2;.65;„ 3;.81; 77;.64;&#x 61.;瑣&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [2;.65;„ 3;.81; 77;.64;&#x 61.;瑣&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised ) Modeling and Effects Review ApplicabilityPage 17of Table 3Gownwash for Gaytiµe (gCµper 1 lbChr)Gistance froµ the Property Iine (feet)Stack Height(feet)9.99.38.79.78.37.87.36.89.48.67.46.96.4D.69.38.67.97.36.76.3D.8D.DD.14.89.48.77.46.86.3D.9D.DD.14.84.D4.23.79.39.39.39.38.67.D6.D6.1D.7D.34.94.64.34.13.83.63.43.2�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [2;.65;„ 3;.81; 77;.64;&#x 61.;瑣&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [2;.65;„ 3;.81; 77;.64;&#x 61.;瑣&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised ) Modeling and Effects Review ApplicabilityPage 16of Table 2No Gownwash for All Hours (gCµper 1 lbChr)Gistance froµ the Property Iine (feet)Stack Height(feet)9.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.87.D6.6D.9D.29.88.D7.D6.6D.9D.29.88.D7.D6.6D.9D.29.98.77.97.D6.6D.9D.29.88.D7.46.66.1D.6D.29.38.37.36.DD.7D.2

4.89.78.67.86.3D.74.69.68.37.1
4.89.78.67.86.3D.74.69.68.37.16.1D.D4.64.28.98.27.46.86.1D.D4.94.43.98.87.36.2D.7D.34.94.64.23.98.37.26.2D.34.44.23.93.73.D8.47.46.76.1D.D4.94.43.83.42.92.68.37.26.2D.44.64.23.83.D3.22.82.6�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [2;.65;„ 3;.81; 77;.64;&#x 61.;瑣&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [2;.65;„ 3;.81; 77;.64;&#x 61.;瑣&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised ) Modeling and Effects Review ApplicabilityPage 1Dof Table 1Gownwash for All Hours (gCµper 1 lbChr)Gistance froµ the Property Iine (feet)Stack Height(feet)9.99.38.79.28.47.87.36.89.48.47.66.96.4D.67.16.4D.8D.DD.14.89.17.96.2D.D4.D4.23.78.77.D6.DD.7D.14.D4.13.73.43.2�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 14of Appendix CScreening TablesThe screening tables are used to deterµine a conservative estiµate of the ground level concentration of a cheµical species froµ an eµission point. These tables provide conservative unit iµpact µultipliers for a particular eµission point based upon the source’s stack height and distance froµ the nearest property line. The following instructions apply to the selection and use of Tables 1 through 4:Utilize linear interpolation between height and distance paraµeters in the tables to deterµinea µore accurate unit iµpact µultiplier, if desired.Extrapolation with heights or distances greater than the values listed in the tables is not allowed.Assuµe that daytiµe hours are between 6 a.µ. and 6p.µ.Geterµine if the source will be downwashed. Gownwash is a terµ used to represent the potential effects of a structure on the dispersion of eµissions froµ a source. If the source is downwashed, use Table 1 or 3; if the source is not downwashed, use Table 2 or 4. A source is downwashed if each of the three conditions below is satisfied.The source is characterized as a point source. Gownwash does not apply to sources characterized as area or voluµe sources.The stack height of the source is less than the good engineering practice stack height (H). Hdefined as the greater of:6D µeters, µeasured froµ the groundlevel elevation at the base of the stack; For stacks in existence on January 12, 1979 and the owner or operator had obtained all applicable perµits or approvals required under 40 CFR parts D1 : = 2.DH here: H = structure height;For all other stacks= H + 1.DIhere: I = the lesser of the structure height or µaxiµuµ projected width (the width as seen froµ the source looking towards the nearest property line) of the structure; andThe structure is sufficiently close to the stack, as defined whenG ≤ DI,where: G = the distance between the structure and the stack.If the source is located near µore than one structure, deterµine downwash applicability with the structure whose diµensions result in the highest GEP stack height. This structure will cause the greatest downwash effects. Gownwash µay be applicable even in cases where the building is not between the source and the nearest property line.�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 13of Appendix BT

oxicology Eµissions Screening IistEµis
oxicology Eµissions Screening IistEµissions froµ the following facilities have been reviewed for health effects and are not expected to cause adverse health effects. These do not require additional review through the MERA process. Odor and particulate eµissions froµ agricultural, food processing, or aniµal feeding or handling facilities.Eµissions of particulates froµ abrasive blast cleaning provided they do not contain any of the following:asbestos;µetalsand µetal coµpoundswith an ESI of less than D0 µgCµ3that are in a concentration of greater than .0%; orcrystalline silica at greater than or equal to 1 percent (weight) of the total particulate weight.Eµissions of particulate µatter, except for µetals, µetal coµpounds,silica, froµ controlled surface coating operations. Controlled surface coating operations are those that capture and abate particulate µatter with a water wash or dry filter systeµ (at least 98% reµoval efficiency) and vent through an elevated stack with no obstruction to vertical flow.Eµissions of particulate µatter froµ rock crushers, concrete batch plants and soil stabilization plants.Eµissions froµ boilers, engines, or other coµbustion units fueled only by pipelinequality natural gasas well as eµissions froµ the coµbustion of natural gas in control devices. Eµissions froµ flares, heaters, therµal oxidizers, and other coµbustion devices burning gases only froµ onshore crude oil and natural gas processing plants, with the exception of eµissions froµ glycol dehydrators and aµine units. Eµissions of volatile organic coµpounds froµ eµergency diesel engines.Eµissions of freons that have ESIs greater than1D,000 µgCµ3 froµ any facility.Eµissions of the following gases, which have been classified as siµple asphyxiatesfroµ any facility.argoncarbon dioxideethaneheliuµhydrogenµethane nitrogenpropanepropylene�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 12of round evel oncentration (GICThe ground level concentration f a constituent in µicrograµs per cubic µeter (µgCµ3) as predicted by µodeling or µeasured by µonitoring.GICµaxMaxiµuµ offproperty ground level concentration for the appropriate averaging tiµe of the cheµical species eµitted froµ all eµission points in the iµpacts evaluation, in µgCµGICniMaxiµuµ nonindustrial offproperty ground level concentration for the appropriate averaging tiµe of the cheµical species eµitted froµ all eµission points in the iµpacts evaluation, in µgCµ. longterµAn annual averaging period.National Aµbient Air Quality Standards (NAAQS)Ievels of air quality to protect the public health and welfare (40 Code of Federal Regulations (CFR)§D0.2). Priµary standards are set to protect public health, including the health of “sensitive” populations such as asthµatics, children, and the elderly froµ the effects of “criteria air pollutants” and certain noncriteria pollutants. Secondary standards are set to protect public welfare, including protection against decreased visibility, daµage to aniµals, crops, vegetation, and buildings.industrial receptorA receptor type such as residential, recreational, coµµercial, business, agricultural, or a school, hospital, daycare center, or church. In addition, receptors in zoned or undeveloped areas are considered nonindustrial. A receptor is a location where the public could be exposed to an air constituent in the aµbient air.refined µodelingAn air dispersion µodel with refined input paraµeters including hourly µeteorological data, µultiple facilities, and facility locations. Ground level concentrations are deterµined across a receptor grid and are µore representative of actual concentrations than those obtained froµ screen µodeling.screen µodelingA siµple

air dispersion µodel with liµited inpu
air dispersion µodel with liµited input paraµeters that yields a conservative estiµate of the ground level concentration for a single facilityas a function of distance froµ the facility. short terµA onehour averaging period.siteThe total of all stationary sources located on one or µore contiguous or adjacent properties, which are under coµµon control of the saµe person (or persons under coµµon control) (30 TAC § 122.10). sitewide µodelingModeling (refined or screening) of eµissions froµ all eµission points and areas on a contiguous property or at a site. Sitewide µodeling includes all sources authorized under 30 TAC Chapters 106 and 116. Note that de µiniµis eµissions under 30 TAC § 116.119 are not included for sitewide µodeling deµonstrations.sourceA point of origin of aircontaµinants, whether privately or publicly owned or operated (30 TAC § 116.10).unit iµpact µultiplier—An EPN specific factor derived by running a dispersion µodel with a unit eµission rate of 1.0 lbChr or 1.0 gCsec. The unit iµpact µultipliercan be µultiplied by the eµission rate to deterµine the ground level concentration resulting froµ those eµissions. �� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 11of Appendix AGlossaryPlease note that there are often differences in terµ usage and terµ definitions between the state and federal regulatory agencies. However, when conducting a MERA evaluation with this docuµent, please refer to the following definitions.air contaµinantParticulate µatter, radioactive µaterials, dust fuµes, gas, µist, sµoke, vapor, or odor, including any coµbination of those iteµs, produced by processes other than natural (Texas Health andSafety Code (THSC) §382.003). ir dispersion µodelµodel ofthe dispersion and transport of contaµinants in the atµosphere, used to estiµate the ground level concentration resulting froµ the eµission of a contaµinant, as further described in the “Air Quality Modeling Guidelines” docuµent (APGG6232).air pollutionThe presence in the atµosphere of one or µore air contaµinants in such concentration and of such duration that are or tend to be injurious to or to adversely affect huµan health or welfare, aniµal life, vegetation, or property, or interfere with the norµal use and enjoyµent of aniµal life, vegetation, or property (THSC §382.003).aµbient aire portion of theatµosphere, external to buildings, to which the general public has access (30 Texas Adµinistrative Code (TAC) § 101.1). For purposes of the MERA, aµbient air is all air outside theproperty line.Air Pollutant Watch Iist (APWI)A list of geographic areas for which aµbient air quality µonitoring data indicates persistent, elevated concentrations of toxic air contaµinants. The list and its accoµpanying prograµs aiµ to reduce eµissions of APWI contaµinants by engaging stakeholders, notifying the public, and requiring additional scrutiny for air perµit applications that propose increases of an APWI contaµinant in an APWI area. This list was established and is µaintained by the TCEQ in coµpliance with the Texas Health and Safety Code, Title D, Subtitle C, Chapter 382. authorizationA µechanisµ to allow the release of eµissions of constituents into aµbient air.Typical authorizations are PBRs, SPs, and casecase NSR Perµits.cheµical speciesAn individual air contaµinant with a specific effects screening level.criteria pollutantA pollutant for which a NAAQS has been defined. µission oint uµber (EPN)A unique identifier for a point of eµission release into the aµbient air.Effects Screening evel (ESI)Screening levels used in TCEQ’s air perµitting process to evaluate the predicted iµpacts of air dispersion µodeling. They are used to evaluate the potential for effects to occu

r as a result of exposure to concentrati
r as a result of exposure to concentrations of contaµinants in the air. ESIs are based on data concerning health effects, the potential for odors to be a nuisance, and effects on vegetation. They are not aµbient air standards. If predicted airborne levels of a constituent do not exceed the screening level, adverse health or welfare effects are not expected. If predicted aµbient levels of constituents in air exceed the screening levels, it does not necessarily indicate a probleµ but rather triggers a review in µore depth.facilityA discrete or identifiable structure, device, iteµ, equipµent, or enclosure that constitutes or contains a stationary source, including appurtenances other than eµission control equipµent. A µine, quarry, well test, or road is not considered to be a facility (THSC§382.003 and 30 TAC §116.10).�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 10of Step 6: Ratio TestSuµ the eµission increases froµ the project to obtain the total project increase, including planned MSS and production increases. Go not include any eµission decreases.Suµ the currently authorized eµissions and all previously unevaluated eµission froµ all eµission points on the site, along with the new and increased eµissions froµ the project to obtain the proposed sitewide eµissions.Step 6: Is the following inequality true? ���where:GICµax = The µaxiµuµ ground level concentration for the appropriate averaging tiµe, in µgCµ. ESI = The effects screening level for the appropriate averaging tiµe, in gCµ. The project increase, in lbChr ortpy. = The proposed sitewide eµissions, in lbChr or tpy.If “No” Step 7.If “Yes” Step 8. The MERA is coµplete.Step : Sitewide odeling.Conduct sitewide µodeling in accordance with AGMT guidance; Update sitewide µodeling froµ a recently approved project to include the project increase and any previously unevaluated eµissions;Subµit µonitoring data per AGMT guidance and deµonstrate that the µonitoring data are representative of near worstcase iµpacts and should be used instead of sitewide µodeling. Contact the perµit reviewer to arrange a µeeting to discuss currently available µonitoring data or to receive guidance forand approval of, a strategy to collect µonitoring data.Sitewide µodeling applies to eµissions froµ all eµission points on propertiesidentified in single propertyline designations between µultiple owners.TCEQ staff will evaluate the µodeling analysis to deterµine if it is appropriate to proceed to Step 8. Step : GocuµentationGocuµent the MERA evaluationand provide all supporting inforµation. The appropriate TCEQ staff will review and evaluate the iµpacts analysis.�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 9 of Step D: MSSEvaluationStep DA: Is the cheµical species one of thefollowing?AcroleinAcrylonitrileBenzeneBroµine1,3butadieneCarbon disulfideChlorineChloroforµEpichlorohydrinFluorineForµaldehydeHydrochloric acid (HC)Hydrofluoric acid (HF)HydrazineMercaptansMethyl broµideMethylenediphenyl diisocyanate(MGI)PhosgenePhosphineStyrene (odor)Toluene diisocyanate (TGI)Any cheµical species with a shortterµESI <2 µgCµIf “Yes” → Step 6.If “No” →Step DB.Step DBWill the plannedMSS eµissions µeet all of the following thresholdsfor the corres

ponding coluµn as shown belowGround Ie
ponding coluµn as shown belowGround Ievel Concentration (µgCµExceedances per Year (GICµax≥ 1 × ESIλ ≤ 24GICµax≥ 2 × ESIλ ≤ 12GICµax≥ 4 × ESIλ ≤ 6GICµax≥ 10 × ESIλ =GICµax> 20 × ESIλ = 0If “Yes” → The MERA is coµpletefor the MSS eµissions. If “No” →Step 6. �� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 8 of Step 4ProjectwideModelingModelthe MSS and production eµissionfor the project. Geterµine a GICµaxfor production eµissions and a GICµaxfor MSS eµissions.Modelthe MSS and production eµissions for the project coµbined with all new and increaseeµissions since the µost recent sitewide µodeling. Geterµine a GICµaxfor production eµissions and a GICµaxfor MSS eµissions.Go not include eµission decreases.Historical µodeling records µay be used to deterµine GICµaxvalues for this step.Step : Will the following thresholds be µet at the location of the GICµax? Planned MSS OnlyProduction OnlyGICµax≤D0% ESI for the project and all new and increased planned MSS eµissions since the µost recent sitewide µodelingANGGICµax≤2D% ESI for the projectGICµax≤2D% ESI for the project and allnew and increased production eµissions since the µost recent sitewide µodelingANGGICµax≤10% ESI for the projectIf “Yes” for both Production and Planned MSS Step 8. The MERA is coµplete.If “Yes” for Production and “No” for Planned MSSThe MERA is coµplete for production eµissions. MSS eµission µust be evaluated inStep . If “No” for ProductionStep 6. �� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 7 of Exaµple:Eµission Rate Increase (lbChr)gCµGistance(feet)Height(feet)X ValuegCµC lbChr)20,00020,000�=10.10.1252µ�ℎ�ℎ�50µ�ℎ�10ℎ��≤0.120000µ�756µ�500µ�000µ�256µ�000µ�In this exaµple, the cheµical species evaluated fallout at Step 3 because the increase in total ground level concentration is less than 10% of the ESI.�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 6 of Shortterµ ESI(μgCµProduction Eµissions Increase (lbChr)MSS Eµissions Increase(lbChr)2 ≤ESI < D00≤ 0.040.1D00 ≤ ESI < 3D00≤ 0.13D00 ≤ ESI ≤ 0.40.4If “Yes” The MERA is coµplete. Proceed to Step 8 for docuµentationIf “No” →Step 3. Step 3: 10% of ESI EvaluationEvaluate eµission increases in this tep. Go not include eµission decreases.For each EPN (EPN), obtain the unit iµpact µultiplier (X), using either the Screening Tables found in Appendix C or an approved EPA µodel.Use the following equation to conservatively predictiµpacts froµ the project:���

D835DC3A;��
D835DC3A;��� = �=1here:GICµax= The µaxiµuµ offproperty ground level concentration for the appropriate averaging tiµe of the cheµical species eµitted froµ all eµission points in the iµpacts evaluation, in µgCµ. The unit iµpact µultiplier obtained froµ the Screening Tables in Appendix C or an approved EPA Model for EPN, in µgCµper lbChr.Theprojecteµissionrate increase of the cheµical species being evaluated, froµ EPNin lbChr.n = The total nuµber of eµission points. Step 3: Is the following inequality true?������≤��∗here: = he effects screening level for the appropriate averaging tiµe, in gCµfor the cheµical species being evaluated. If “Yes” Step 8. The MERA is coµplete. If “No” → Step 4. �� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage D of Cheµical species on the Air Pollutant Watch Iist (APWI) are subject to the requireµents detailed in the “Perµit Application Guidance for Coµpanies Iocated in an Air Pollutant Watch Iist Area” guidance docuµent, and µust also be evaluated usingthe MERA. Also, a casecase analysis not relying on the steps of the MERA µay be required for any specific situation as deeµed appropriate by the perµit reviewer and APG µanageµent. A retrospective MERA evaluation µay be required for correctionsin representations or eµission calculationsThis deterµination will be µade on a casecase basis. All refined µodeling should be conducted in accordance with direction froµ APG staff and the “Air Quality Modeling Guidelines” docuµent (APGG 6232).A pre-µodeling µeeting or teleconference with the applicant, perµit reviewer and µodeling teaµ is recoµµended before refined µodeling is perforµed.Step 1: No Net IncreaseSuµ the proposed eµission increases and decreases froµ each EPN to deterµine the net change in eµissions.Step 1: Is the net change in eµissions less than or equal to zero?If “Yes” Conduct a qualitative analysis to deterµine if the project will result in an increase in the GICµaxat the propertyline. The qualitative analysis should include factors affecting the GICµaxsuch as distance froµ the property line and the type of source (point, area, or voluµe). ubµit the analysis as requested bythe perµit reviewer. Goes the qualitative analysis indicate that the GICµaxwill increase?If “No” The MERA is coµplete. Proceed to Step 8 for docuµentation.If “Yes” Step 2. If “No” →Step 2Step 2: Ge Miniµis IncreaseSuµ the shortterµeµissionincreases froµ each EPN to obtain the total shortterµ project increase. Go not include eµission rate decreasesfroµ any EPNInclude any unevaluated eµissions such as eµissions froµ PBRs, SPs, or any other authorization.If MSS and production eµissions occur siµultaneously, the MSS and production eµissionsinto one eµission rate. Otherwise, calculate separate rates. Step 2: Is the longterµ ESI ≥ 10 % of the shortterµ ESI? Are total shortterµ project increases less thanthe appropriatede µiniµis levelsbelow? If MSS and production eµissions occur siµultaneously, evaluate the coµbined eµission rates against the production de µiniµis levels. Otherwise, evaluate MSS and production eµissions separately against their respective de µiniµis levels. �� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x

58.;艇&#x ]/S;&#xubty;&#xpe /;oot;&
58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 4 of if previous iµpacts were approved based on a liµited frequency of exceedances.For other cases, a longterµ iµpacts is not required unless requested by the perµit reviewer. The input of a screening µodel is an eµission rate in µass per unit of tiµe and the output is a µaxiµuµ 1-hr ground level concentration(GICµax), in units of µicrograµs per cubic µeter (µgCµ3). Therefore, if a longterµ iµpacts evaluation is necessary and screen µodeling is used, an annual GICµaxµust be calculated by µultiplying: an annual unit iµpact µultiplier, an eµission rate representative of the annual eµission ncreaseassociated ith the 1-hr GICµax. For SCREEN3, the annual unit iµpact µultiplier is deterµined by µultiplying the hourly unit iµpact µultiplier by 0.08, which is an annual conversion factor that accounts for the variation in µeteorological conditions throughout the year. For AERSCREEN the annual unit iµpact µultiplier is deterµined by µultiplying the hourly unit iµpact µultiplier by the annual conversion factor 0.1. An annual conversion factor is not needed if a refined µodel that can calculate an annual GICµaxis used. To deterµine the eµission rate representative of the annual eµissions increase, convert the tonperyear increase in eµissions to a poundhour rate using 8760 hours per year and 2000 pounds per ton. As an exaµple, an eµission source has an hourly unit iµpact µultiplier of 100 µgCµ, generated using SCREEN3,and an annual eµission rate of 40 tpy. The annual eµission rate is converted to an hourly rate as shown below:40 tpy x 2000 lbCton C 8760 hoursCyear = 9.134 lbChrThe µaxiµuµ 1hr ground level concentration is µultiplied by 0.08 yield an annual unit iµpact µultiplier: 100 µgCµx 0.08 = 8 µgCµThe annual GICµaxis then calculated by µultiplying that annual unit iµpact µultiplier and that eµission rate representative of the annual eµissions:µgCµx 9.134 pph = 73.1 µgCµESIs should be deterµined froµ the Toxicity Factor Gatabase, accessed through the TAMISdatabase. Instructions for using the database can be found on the Toxicology Givision’s website. If a cheµical species doesnot have an assigned , itµay be exeµpted froµ a MERA effects evaluation,unless an evaluation is requested by the perµit reviewer. However, for certain cheµical species, such as cheµicals to be approved under cheµical flexibility perµit provisions or roprietary µixtures, a new ESIµaybe requested froµ the Toxicology Givision. In addition, a default ESI of 2 µgCµµay be used for a species with an unknown ESI.Unless otherwise stated, each step in theMERA evaluation µust include all eµissions associated with the project, including: MSS eµissions that will be authorizedunder PerµitBy Rule (PBRs). Eµissions froµ PBRs and Standard Perµits (SPs) that are beingconsolidatedby incorporation into the perµit.�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 3 of How to Geterµine the Scope of Modeling and Effects Review for Air PerµitsStep 0: Applicability and ProceduresMERA Evaluation ApplicabilityA MERA evaluation µust be conducted for all cheµical species whose shortterµ or longterµ allowable eµission rate will increase froµ any eµission point nuµber (EPN) throughthe project. The change in an allowable eµission rate is calculated as the difference between the proposed µaxiµuµ allowable eµission rate and the currently perµitted µaxiµuµ allowable eµission rate. Throughout the reµainder of this docuµent “allowable eµission rates” will be referred to as eµission rates” or “eµissions.”The

followingare exeµpt froµ a MERA evalua
followingare exeµpt froµ a MERA evaluation: All cheµical species for which there is a state air quality standard or NAAQS, other than particulate µatterspeciesthat have an Effects Screening Ievel (ESI) published by the TCEQ Toxicology Givision. The ESI database will reference the NAAQS in place of an ESI if a MERA evaluation is not required for a particulate µatterspecies. The “Air Quality Modeling Guidelines” docuµent (APGG 6232) provides the process for evaluating cheµical species for which there is a state air quality standard or NAAQS.Facilities and cheµical species listed on the Toxicology Eµissions Screening Iist (seeAppendixB).Cheµical species for which there is not a current ESI listed in the Toxicity Factor Gatabase, accessed through the Texas Air Monitoring Inforµation Systeµ (TAMIS) database via the Toxicology ESI suµµary and detail reports. While no effects review is required, such cheµical species µust satisfy the BACT and other requireµents. In addition, the perµit reviewer and APG µanageµent have the discretion to perforµ an effects review outside of the MERA process.This exeµption does not apply to cheµical species being authorized under cheµical flexibility perµit provisions. General ProceduresThe following appliesto the health effects review described in the MERAprocess, unless otherwise specified:The MERA evaluation µust be conducted for each cheµical species individually(except in cases where the Toxicology Givision has developed an ESI for a blend such as gasoline), and µust include all EPNs in the project with an increasing allowable eµission rate of that cheµical species.A shortterµ iµpacts evaluation µust be conducted for all cheµical species with an increase in shortterµ eµissions. A longterµ iµpacts evaluation µust be conducted for cheµical species with an increase in longterµ eµissions under the following conditions:for all cheµical species with a longterµ ESI that is less than 10 percent of the shortterµ ESI ; if a cheµical species does not have an assigned shortterµ ESI, but does have an assigned longterµ ESI; or �� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 2 of Suµµary of Significant ChangesRevision GateGescription of ChangesFebruary 2018Iµprove ease of use and clarity, reµoved infrequently used steps,revised µultipoint equation in previous Step D.Cheµical species for which there is not an ESI µay be exeµpted froµ a MERA evaluation.July 2009Provided additional clarity pertaining to unevaluated and MSS eµissionsand added Appendix G, Toxicology Effects Evaluation Procedure.August 2008Updated requireµents for APWI Constituents, added criteria for planned MSS and unevaluated eµissions and added the terµ “perµitwide,” established µagnitude and frequency criteria for planned MSS eµissions.October 2001Reµoved special interest constituents, and replaced with Air Pollutant Watch Iist, corrected µultipoint equation in Step D, and added inforµation about single property line designations.August 1998Updated flowchart, added requireµents for constituents of special interest, and added effects evaluation procedures and updated the forµat.July 1993Original MERA Guidance Gocuµent�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.95; 3;.01; 55;.08;&#x 46.;≈&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.95; 3;.01; 55;.08;&#x 46.;≈&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 1 of IntroductionThe Texas Coµµission on Environµental Quality (TCEQ) regulate

s air quality in the state of Texas thro
s air quality in the state of Texas through the Texas Clean Air Act (TCAA), located in Chapter 382 of the Texas Health and Safety Code and rules, including those in Title 30 Texas Adµinistrative Code (TAC)Chapter116.The TCEQ staff conducts a preconstruction technical review during the air perµitting process. This review ensures that the operation of a proposed facility will coµply with all the rules of the TCEQ and intent of the TCAA, and not cause or contribute to a condition of air pollution. A review of an air perµit application involves an assessµent of huµan health and welfare effects related to eµissions froµ production and planned µaintenance, startup, and shutdown (MSS) activities.The huµan health and welfare effects are evaluated for applications withnew andCor µodified sources of aircontaµinants, as well as in perµitting actions involving retrospective reviews or previously unevaluated eµissions. Contaµinants for which stateair quality standardsor National Aµbient Air Quality Standards (NAAQS) exist are evaluated using a coµparison between predicted concentrations and the standards.The evaluation procedures for these contaµinants are covered in detail in the TCEQ Air Quality Modeling Guidelines – APGG 6232If there are no state or national aµbient air quality standards for a contaµinantit is evaluated through the TCEQ’s Modeling and Effects Review Applicability (MERA) process. Guring the course of the MERA process, the scope of air dispersion µodeling and effects review is deterµined.While thisdocuµent provides a general process and defines µiniµuµ considerations for agency staff’s air quality iµpacts analysis, this docuµent is not regulatory and does not liµit the perµit reviewer’s ability to require the applicant to provide additional inforµation. In addition, the perµit reviewer and Air Perµits Givision () µanageµent have the discretion to perforµ an effects review outside of the MERA process.The MERA process begins with Step 0, which inforµs the user of the general procedures and practices to be followthroughout the MERA process. Steps 1 through 7 detail the criteria used to evaluate the health effects of an air contaµinant. The initial steps in the MERA process are designed to be siµple and conservative. As one progresses through the process, the steps require µoredetail and result in a µore refined (less conservative) analysisSitewide air dispersion µodelingis conducted at Step 7e results are evaluated usingthe Toxicology Effects Evaluation Procedure in Appendix G. If a contaµinantevaluated on a cheµical species by cheµical species basis, µeets the criteria of a step, the review of huµan health and welfare effects is coµplete. A cheµical species is said to “fall out” of the MERA process at this step, and the MERA docuµent will direct the user to Step to docuµent the evaluation. If a contaµinant does not µeet the criteriaof a step, the docuµent will direct the user to theappropriate next step. It is acceptable toskip stepsthe MERA process and proceed directly to µore detailed steps.This docuµent replaces Modeling and Effects Review Applicability, APGG D874, July 2009.��TCEQ – (APGG D874vD, Revised 03) Modeling and Effects Review ApplicabilityPage Table of ContentsIntroduction 1Suµµary of Significant Changes 2How to Geterµine the Scope of Modeling and Effects Review for Air Perµits 3Step 0: Applicability and Procedures 3Step 1: No Net Increase DStep 2: Ge Miniµis Increase DStep 3: 10% of ESI Evaluation 6Step 4: Projectwide Modeling 8Step D: MSS Evaluation 9Step 6: Ratio TestStep 7: Sitewide Modeling.Step 8: GocuµentationAppendix A: GlossaryAppendix B: Toxicology Eµissions Screening IistAppendix C: Screening TablesAppendix G: Toxicology Effects Evaluation ProcedureAppendix E: MERA Flowchart��TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage Air Perµit Reviewer Reference GuideAPGG D874Modeling and Effects Review Applicability (MERA) Air Perµits Givision Texas Coµµission on Environµental Quality March 2018 �� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„

3;.81; 55;
.64;&#x 58.;艇&#
3;.81; 55;
.64;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;
.64;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 03C18) Modeling and Effects Review ApplicabilityPage 20of Appendix E: MERA FlowchartLT ESL of ST ESLANDST emis ≤ de minimis levels? StartStep Applicability troceduresGLCmaxESLNo5AChemical species on list5BMSS GLCmaxThresholdsNoMeet Ratio TestNoStep EndStep DocumentationYesYeswesults reviewed by TCEQ Stafftrod GLCmaxThresholdsMSS GLCmaxThresholdsYesNoYesIf results are allowableor acceptableNoNoYesNoYesbet emis ≤ 0?NoYesYesKeyemisemissionsincrincreaselongtermprodproductionSTshorttermThis flowch is suµµry of he MERA nd is no inended sue for his guidnceSitewide aodeling�� &#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;&#x/Att;¬he; [/;ott;&#xom ];&#x/BBo;&#xx [6;.65;„ 3;.81; 55;.24;&#x 58.;艇&#x ]/S;&#xubty;&#xpe /;oot;r /;&#xType;&#x /Pa;&#xgina;&#xtion;&#x 000;TCEQ – (APGG D874vD, Revised 0) Modeling and Effects Review ApplicabilityPage 3 of How to Geterµine the Scope of Modeling and Effects Review for Air PerµitsStep 0: Applicability and ProceduresERA Evaluation ApplicabilityA MERA evaluation µust be conducted for all cheµical species whose shortterµ or longterµ allowable eµission rate will increase froµ any eµission point nuµber (EPN) throughthe project. The change in an allowable eµission rate is calculated as the difference between the proposed µaxiµuµ allowable eµission rate and the currently perµitted µaxiµuµ allowable eµission rate. Throughout the reµainder of this docuµent “allowable eµission rates” will be referred to as eµission rates” or “eµissions.”The followingare exeµpt froµ a MERA evaluation: All cheµical species for which there is a state air quality standard or NAAQS, other than particulate µatterspeciesthat have an Effects Screening Ievel (ESI) published by the TCEQ Toxicology Givision. The ESI database will reference the NAAQS in place of an ESI if a MERA evaluation is not required for a particulate µatterspecies. The “Air Quality Modeling Guidelines” docuµent (APGG 6232) provides the process for evaluating cheµical species for which there is a state air quality standard or NAAQS.Facilities and cheµical species listed on the Toxicology Eµissions Screening Iist (seeAppendixB).Cheµical species for which there is not a current ESI listed in the Toxicity Factor Gatabase, accessed through the Texas Air Monitoring Inforµation Systeµ (TAMIS) database via the Toxicology ESI suµµary and detail reports. While no effects review is required, such cheµical species µust satisfy the BACT and other requireµents. In addition, the perµit reviewer and APG µanageµent have the discretion to perforµ an effects review outside of the MERA process.This exeµption does not apply to cheµical species being authorized under cheµical flexibility perµit provisions. General ProceduresThe following appliesto the health effects review described in the MERAprocess, unless otherwise specified:The MERA evaluation µust be conducted for each cheµical species individually(except in cases where the Toxicology Givision has developed an ESI for a blend such as gasoline), and µust include all EPNs in the project with an increasing allowable eµission rate of that cheµical species.A shortterµ iµpacts evaluation µust be conducted for all cheµical species with an increase in shortterµ eµissions. A longterµ iµpacts evaluation µust be conducted for cheµical species with an increase in longterµ eµissions under the following conditions:for all cheµical species with a longterµ ESI that is less than 10 percent of the shortterµ ESI ; if a cheµical species does not have an assigned shortterµ ESI, but does have an assigned longterµ ESI; o