' ' > c UNrTED STATES ENVIRONMENTAL PROTECTION AGENCY 

f ^ '\^ REGIONS 

1595 Wynkoop Street 

DENVER. CO 80202-1129 

Phone8(»-227-8917 

http://www.epa.gov/region08 

"•' f>p.ooRef: 8P-AR ^ I ? 20tn 

Brian Gustafson, Administrator 

Air Quality Program 

South Dakota Department of Envirorunent and Natural Resources 

523 East Capitol Avenue 

Pierre, SD 57501-3182 

RE: EPA Preliminaty Comments on August 2010 

Draft Regional Haze State Implementation Plan 

(Public Comment Version) 

Dear Mr. Gustafson: 

EPA has completed a preliminary review of South Dakota's August 2010 draft Regional 

Haze State Implementation Plan (SIP). Our comments and questions are detailed in Enclosures 1 

through 3 to this letter. 

We understand that you intend to consider all comments received on this public comment 

version of the Regional Haze SIP prior to finalizing and adopting the documents for submission 

to EPA. We emphasize that we will only reach a fmal conclusion, and perform our complete 

review, regarding the adequacy of South Dakota's Regional Haze SIP when we act on the South 

Dakota Regional Haze SIP revision through our own public notice and comment mlemaking. 

We look forward to continued communications to resolve the remaining concems with 

the Regional Haze SIP. If you have any questions on EPA's comments, please contact me at 

303-312-6434, or your staff may contact Gail Fallon at 303-312-6281. 

Sincerely, 

X ' '- ^ ' / 

ii-——Canie A. Videtich, Director 

Air Program 

Enclosures 

cc: John Bunyak, NPS 

Sandra Silva, USFWS 

Thomas Dzomba, USFS 
ENCLOSURE 1 

EPA Region 8 Preliminary Comments on the August 2010 Draft Regional Haze SIP 

(Public Comment Version) 

Summary of Major Concems - (see detailed comments for more information); 

• Many comments from our March 12,2010 letter were not sufficiently addressed. All of 

the detailed preliminary comments below pertain to those previous comments and 

provide additional information on areas which are still problematic. 

• Insufficient details were provided on how the best available retrofit technology (BART) 

emission limits will be made enforceable as a practical matter. See conunents #1, #4 and 

#7 below. 

a No identification of the number of years to reach natiu^ conditions was provided as 

required when the Reasonable Progress Goal is less than the Uniform Rate of Progress. 

See comments #5 and #8 below. 

• No four-factor Reasonable Progress analysis was completed. See comment #6 below. 

• Recommend reviewing ARSD regulation references for typographical errors throughout 

both the response to comments (for future clarity in the SIP record) as well as the main 

SIP dociunent. There are numerous errors likely due to the addition of 74:36:21:06, 

which changed the numbering of the subsequent chapters. 

Detailed Comments; 

1. Executive Summary, pp. vii-viii: Additional details are necessary to ensure that BART 

emission limits will be enforceable as a practical matter. The BART emission limits, 

compliance schedules, monitoring, recordkeeping, and compliance determining methods for 

Big Stone I must be specified in the text of the Regional Haze SIP or in a permit that is 

incorporated into the SIP. For example, in your response to our comment on this issue (#1 

and #39 from Appendix D), you relied heavily on requirements of your Title V program 

(ARSD 74:36:05). As this program is not part of the SIP, our concems with reliance on the 

Title V program in this area remain. Two examples of all the various elements of adequate 

language that were coordinated with the States of Wyoming and Colorado are provided in 

Enclosures 2 and 3 for reference. 

2. Table 6-9, p. 91: Footnote 5 references a 1999 EPA Techiucal Bulletin on NOx controls as 

justification for the 35%-90% control efficiency range for the top three options. The large 

range in EPA's bulletin is due to inclusion of selective catalytic reduction (SCR), selective 

non-catalytic reduction (SNCR), and fuel rebuming for wet-bottom boilers. It is well 

documented that SCR achieves the high end of the range. The EPA bulletin also lists a 30%-

70% control efficiency for a group of temperature-reducing controls, including over-fire air. 

Therefore, the proposed BART determination of SCR plus separated over-fire air (SOFA) 

should be better than the 90% control efficiency of SCR alone. In your response to this 

comment (#31 from Appendix D), there was no discussion regarding how the addition of 

1 
SOFA would not contribute to a better than 90% control efficiency. This needs to be 

addressed. 

3. Section 6,3.5, BART Emissions Limits for Big Stone I, pp. 99-103: In order for EPA to 

entertain the establishment of separate BART limits for startup and shutdown conditions, an 

adequate record showing that the otherwise applicable limits are not achievable and that the 

separate startup/shutdown limits constitute BART is required as justification. Your response 

to this comment (#38 fh}m Appendix D) does not provide sufficient justification for 

establishing the separate startup/shutdown limits. We continue to offer to work closely with 

you to establish appropriate 30-day rolling average emissions limits for particulate matter, 

sulfiir dioxide and nitrogen oxides that allow for startiqi/shutdown conditions to help ensure 

SIP approvability. 

4. Section 6.4, BART Requirements, p. 103: According to your proposed revisions to the South 

Dakota Administrative Rules, Chapter 74:36:21:10, a permit modification will be required 

for your BART determination on Otter Tail's Big Stone I. Without seeing the details of such 

permit, it is difficuh to determine whether this section of the SIP adequately addresses 

requirements for enforceability, including appropriate averaging times, compliance 

verification procedures, and recordkeeping and reporting requirements, and proper operation 

and maintenance procedures. As noted in comment #1 above, these requirements must be 

specified either in the text of the Regional Haze SIP or in a permit that is incorporated into 

the SIP. Your response to this comment (# 39 from Appendix D) relied heavily on your 

Title V program which is not part of the SIP and does not fully address this issue. 

5. Section 7.2.1, Breakdown of CMAQ Modeling Results, pp. 106-107: Your response (#47 

from Appendix D) addressed most of our questions with one exception. The SIP must 

provide the number of years necessary to reach natural conditions, as required by 40 CFR 

51.308(d)(l)(ii) when the reasonable progress goal (RPG) is less than the uniform rate of 

progress (URP). While you state in Section 10.3 on page 127 that you believe South Dakota 

can still meet the reasonable progress goals and achieve natural conditions by 2064, the data, 

as currently presented, does not support this proposed conclusion. 

6. Section 7.2.2, Four Factor Analysis, pp. 107-109: DENR's determmation that a four-factor 

analysis is not warranted at this time is not acceptable. A four-factor analysis must be 

completed in establishing the RPGs for Class I areas impacted by South Dakota emissions, as 

well as in justifying a RPG that is less than URP. Despite your response to this comment 

(#49 from Appendix D) regarding minimal contribution fi-om point sources to visibility 

impairment, a four-factor analysis is required to Justify this conclusion. Again, we suggest 

looking for additional reductions fi-om GCC Dacotah, Ben French, and Pete Lien as well as 

the potential from the close proximity of Rapid City to Badlands. 

7. Section 8.5.6, Enforceable Emission Limits and Control Measures, p. 116: Though this 

section was slightly reworded per your response (#56 from Appendix D), your intention to 

establish the Big Stone I BART limits and control measure requirements in an ah quality 

permit requires the permits' incorporation into the SIP. The South Dakota draft construction 
permit program regulations are currently under review by otu- office. Until this has been 

approved mto the SIP, it mil not be appropriate to rely upon the program for your BART 

permits. 

Section 10.3, Public Input, pp. 126-127: As noted in comment #5 above, the SIP must 

provide the public with a calculation of the number of years required to reach natural 

conditions if the RPG provides a slower rate of improvement than that needed to attain 

natural conditions by 2064 per 40 CFR 51.308(d)( 1 )(ii). We understand your concems 

regarding assumptions for other states included in the WRAP analysis; however, this SIP 

must include your best estimate of number of years to reach natural conditions with the 

proposed RPGs. Though this section was slightly reworded per your response (#48 from 

Appendix D), the number of years is still lacking. 

ARSD Chapter 74:36:21:12, Federal Land Manager Notification and Review: Your response 

(#65 from Appendix D) did not adequately address our concem related to FLM consultation 

on BART permit reviews. As required by the Regional Haze Rule, the Federal Land 

Managers must be provided a 60-day consultation period prior to any public hearing on the 

Regional Haze SIP. Since a BART permit is an integral part of the Regional Haze SIP, this 

60-day consultation period must extend to FLM BART permit review as well. In addition, 

since any BART permit must be incorporated into the Regional Haze SIP, the 30-day public 

notice for the SIP needs to identify the inclusion of any BART permits. 
ENCLOSURE 2 

EPA Regions - [Preliminary Comments on Wyoming's Regional Haze Monitoring, 

Recordkeeping, and Reporting Requirements (MRR) 

Please note: This document is divided into two sections. The first section provides 

comments on the current MRR language in the State's Regional Haze SIP. We have included 

comments (in italics) and in some instances suggested language. The second section of this 

document contain.s information on SIP MRR elements that need to be added ta the SIP and 

suggested language. 

I I. Current SIP Language for Pacificorp Unit 

The State of Wyoming considers the control effectiveness of a control technology to be 

equivalent to the BART-determined permit limit ..^a m l.ihic \ \ (H.K:\%. I he Male 

siuHilJ cluumc Ihc prL^^:c(iln^ wmencc to road "the .Slate t>l W yumin^ unisidcrs llic BAR 1-

Jclcrniiiicil IXTT!::' ' , ' ' • • •' •; i *•• : i" , i ' 

!i'5rl]ni.'lL'j;i The limit is ba.sed on continuous compliance when Che contrcl equipment is 

well maintained and operated in a manner consistent with gaod air pollution control practices 

for minimizing emissions, iiu- .),ii' inu.^t nuitiuw iiiui iiu- .V/i</n' \uu ^i.>iHpi\ ,\nn U.\H1 ui 

. • i/n l\. hfliiuj 

I iahlf W Unit-by-unit BART determinations for NOx and PM/PMio: 

Unit 

3 

PM/PMioi.. 

4 

P.M/PMioc. 

Pollutant Control Type 

NOx LNB/OFA 

Fabric Filter 0.015 

NOx LNB/OFA 

Fabric Filter 0.015 

Ib/MMBtu 

0.28 (3()-day 

rolline) 

42.1 

0.15 (.10-day 

rolling) 

61.5 

Ib/hr 

784 (.10-day 

roiling) 

615 {.lO-day 

rolling) 

tpy 

3.434 

184 

2.694 

269 

III. Expeditious Installation and Operation of BART 

Uw Srnh' lutih lo induiilf in llii.\ sri. tinn tluii ilw li.'\RTdciermnuittnn I.s ilfrh'nJtrii on 

r/f)/'riii til l>\ /:/' t Ihc Siiiif iiiii\l also prinidi- .i dalf In " hn It il'.f \our, <• nn'tls U> tiwiall 

iind t oni/ih II nil llw ll.\Kr limils, noi iiisi ilw rfi/uinnifni lo insudl ilu iifttipnwn!. /'('/" Ilw 

1{.\RI (iiiidrlincs, \oiint.\ slundj insttdl it>nlrol\ • .../•'.,. ' • priHihiddv. hut no IUIIT 

iliiinjn,- uyit', iiji, r l\l'\ <ii>pro\iii llf ihf SW The State of Wyoming pnnxi^cs that 

PacifiCorp in.stall new low NOx bumers with advanced OFA on Units 3 and 4, in accordance 

with the Division's BART determination, and conduct the required initial performance tests 

no later than December 3!, 2010 and December 31, 2009. respectively. The State of 

Wyoming that PacifiCorp install new full-.scale fabric filters on Units 3 and 4, in 

accordance with the Division's BART determination, and conduct the initial performance 

tests required no later than December 31, 2010 and December 3!, 2012, respectively. _^^ 

iHiioiimini I- U'sttm:. liw ii(>nlicaidi' t.f'.X test nicilwd niiisi he sptu ificd cdimv \\iili ihr 

irftiiitiHV (<l U'siinM and oilier irh'vani infornuilion. 
IV. Proper Maintenance and Operation of Control Equipment 

.\[ all liincN iil'ler the cmiiphance deadline specified in Kspefifv sectionll. ilic 

tmncr/o|)craiur of each B.AK I unit shall maintain, eaiihnite. and t)perate a C'LMS, in lull 

compliance with the requirements found at 40 CFR part 7.S, lo aecurateK mea.sure SOI. 

NOx, diluent iCO; or Oo. and slack ijas \t>lunielric How rale Irom each B.ARl unil. the 

( |;M S shall be used Ui detennine ccmpliuncc with tlie SOI and .NOx B.AK I ciius.sitin 

linuts lor each B.XRI unil 

In deierniinini; eonipiianee wilh ihe S()2 and NOx BARl liniiis. all IXTJIKIS t)teniissii)iis 

shall tx.- included, inclmimi; slarlups. sluiulnwns. emergencies, .uuJ riiallunelnins 

\()Ti:: l\r section .W2(k) of the ('\.\. liXRT litnit<i must he nut coiitinn(H4\lv. The 

ii.i K /' limits section of ihe SI!' need to state that the tt \ K T limits appl\ nt all limes, 

tncliidini: periods of SSM. 

The State of Wyoming :ini[T<»se- that PacifiCorp conduct initial NOx performance tests on 

Units 3 and 4 after the installation of low NOx burners and advanced OFA, within 30 days of 

achieving a maximum design rate, but not later than 90 days following initial start-up. / or 

^ .,. ; '...;;, ...::.,,.: J^J-^- • '•^-^'-- 1--- _- -_ j. ^- il-- -A -L ''J LLIIK 

l'requenc\ of icMina and other reicvoni infornuition. 

Owner/operulur shall suhmil reports ul aii\ requirctl }V'i'"".i ^i ,. l i vi, i,.i \( iv 

wilhin hOe.ilendar il.iNs aftei mmpleluMi ul ihe tcsi If a maximum design rate is not 

achieved within 90 days of start-up. the AQD Administrator may require testing be done at 

the rate achieved and again when u maximum rate is achieved. . ^ ^ "iii > " • • < i '' •' 

init. Ill theprt vhni\ st/i.'»vur >\itii duiH '. II a inaxiinuni desijii lale is imt .lehievetl 

within 'XI davs ot starl-up, ihc AQD Admniisinilor shall require lesiine he tlone .ii the lale 

ayhir' I i: ! . •.- i-: .,,,;..,....,.,.. . i,... . i A test protocol shall be submitted 

for Division approval prior to testing and a written report of the test results shall be .submitted 

to the Division. Testing required by the WAQSR Chapter 6. Section 3 operating permit r 

I • \i.i.yi< • ii.ij'u I '». sccin'O - »'i sci.>iiiii -* may be submitted to 

.satisfy the testing required, llic prior u nient e i\ o relcrcm e to all lIu o;u r.iiun^ lunnu 

rci{uUtti<ms. fhis needs to he replaced with a provision iliat will he in die SIP. 

The State of Wyoming propose that PacifiCorp conduct initial PM/PM 10 performance 

tests on Units 3 iind 4 after the installation of fabric filters within 30 days of achieving a 

maximum design, rate, but not later than 9() days following initial start-up. 

performanie ttstim:. the upplicahle El'A test method must he specified alon\i with the 

treipieih\ of U'\tin<i and other relevani infornuition. 

11 a ma.vinium design rale is noi achieved wiihin ^ ) du\s ot suin-up. ihe .\(.)D 

.Xdmniisiratur shall require lestini; he done at the rale achieved and aizaiii when a 

maximum rate is aehieved. ^.)^ller.^^pel^ator shall suhinii re[H>rt.s of any required 

[X-'rlormance slack lests tor particulate matter, wiihin 60 eaiendar days after complelioii 

otlhe fcsi. In addiliu[i lo annual stack tests, owner/ot>eralor shall Ili!]n'.!'irj^!'riity.!;Llc: 

emissions lor compliance wilh (he 13,\R I" emission limils in accortiaiice wiih ihe 
applicable (\>iiipliaiiee As-uiaiiee Moniiorin'j K\\.V11 plan develo|X'tl ami .ipprose<I HI 

iceofdance w iih 40 (TR part 64. A test protocol shall be submitted for Division approval 

prior to testing and a written report of the test results shall be submitted to tho Division. 

Testing required by the WAQSR Chapter 6, Secdon 3 operating permit may be submitted to 

.satisfy the testing required. Delete ihe prior senieiicc. This is a reteienee lo all ihe 

iper.iiiiiL; ['">•""" 'e::uiaiions. This needs lc> he replaced wilh a provision ihai will be m 

Ihe SIP. 

The State of Wyoming i • i performance tests and compliance with the BART limits for 

N0.< be determined for Units 3 and 4 using a continuous emissions monitoring system 

(CEMS). .iM.JLiii A Illi liii.- pioviMtiiis ill iliis •.Ci-iiiHi. certified in accordance with 40 CFR 

part 60 and data from the CEMS ^h.tll ijw. r tUv requiix' , : 40 CFR part 75. The State of 

Wyoming iniios^^ performance tests for compliance with Lie BART limits ior PM/PMio 

conducted annually following 40 CFR 60.46 and EPA Reference Test Methods 1-4 and 5. 

itii t 

W. .\i)iicndi\ .\ 

\ lesi '.hall coiisi>i iifihree runs, wiiheaeh run .it ieasi 120 miiiuies iii ihu-ihi'• 

,vi!,-,i,n^ . .,,,,,,1, ,r/,n,i,v .i,,,,i,r,| nhi. ! ,•. TestiHg fcquifcd by the WAQSR Chapter 

6. Section 3 operating permit may be submitted to satisfy the testing required. IVIcie ihe 

prior sentence. I his is a lelereiice lo all the opcraling t)eriitil iciiuiatioiis. I his needs to he 

replaced wilh a provision lhat will he in the SIP 

II. SIP Elements that must be added: 

• ^-ji-iL^ •"• •' -j ^•- " , .miiiii; lime lot ihe various emission Jiiiiits. including 

• SIP must contain monitoring and compliance determination specifics. {See 

Section at the end of this analysis} 

• The SIP mu.st also contain the specific recordkeeping and reporting requirements. 

(See Footnote 1 for suggested language) 

« The SIP must explicitly state those records the sources are required to keep to assess 

compliance for the time frame specified in the SIP. Records must be commensurate 

with regulatory requirements. Records must be available for examination upon 

request. (See Footnote 1 for suggested language) 

• The SIP must give reporting .schedules and reporting formats. 

• Recordkeeping 

o The recordkeeping must be required such that failure to do so would be a 

.separate violation. 

o Preferably, the SIP should specify that records must be kept for at least 

five years' 

Suggested language - Owner/operator shall maincuin the following records for ut lea.st live years, ami they 

must be availahle on request: 

1. All CE.MS data, stack test data, and data collected pursuant to the CAM plan, including the date, 

place, and time of sampling, measurement, or testing; parameters sampled, measured, or tested and results; 

ihe company, entity, or perstin that performed the testing, if applicable; and any tield daia sheets from 

testing. 
The SIP should require periodic reporting.' 

The SIP should require timely deviation reporting.'^'* 

Include definitions for. (1) boiler operating day^; (2) CEMS^; and (3) substitute 

hourly emission rates^ 

Suggested language for monitoring and compliance determinations: 

1. Pounds Per Hour And Tons Per Year Limits 

For any hour in which fiiei is combusted in the boiler, owner/operator shall 

calculate hourly S02 and NOx emissions in pounds at the CEMS in accordance with the 

monitoring procedures and requirements of 40 CFR part 75. In calculating hourly mass 

emissions and emissions rate.s, owner/operator shall use the conversion procedures 

specified in 40 CFR part 75, Appendix F. For any hour that valid, quality assured CEMS 

data are unavailable, emissions shall be calculated in accordance with the mis.sing data 

substitution procedures in 40 CFR part 75. subpart D. These hourly values shall then be 

used to determine compliance in accordance with the particular limit's averaging period, 

as follows: 

3. Recofd.s of quality cs.surance and quality control activities fbr emissions measuring systems 

including, but nut limited to, any records required by 40 CFR Pan 73. 

i. Records of all major maintenance activities conducted on emission units, air pollution control 

equipment and CEMS. 

4. Any other records required by 40 CHR parts 64 and 75. 

' Suggested language - Owner/operator shall also submit quarterly CEMS performance reports, to include 

dates and duradon of each period during which the CEMS was inoperative (except for zero and span 

adjustments and calibradon checks). rea.son(s) why the CEMS was inoperative and steps taken to prevent 

recurrence, any periods for which missing data substitution procedures were used, any CEMS repairs or 

adjastmcnts. and results of any CEMS performance tests required by 40 CFR pan 75 (Relative Accuracy 

Test Audits. Relative Accuracy Audits, and Cylinder Gas Audits). 

' Suggested language - Owner/operator shall submit quarterly excess emissions repuns no later than the 

.10^ day following the end of each calendar quarter. Excess emissions means emissions that exceed the 

emis.sions limits specified in above. 

' Sugge.sted language - Owner/operator shall also submit quarterly reports of any exceedances or excursions 

under the approved CAM plan, and steps taken to correct the exceedances or excursions, in accordance 

widi40CI-'R64.<i(a). 

' Define boiler operating day as "any 24-hour period between 12:U0 midnight and the following midnight 

during which any fuel is combusted at any time at the steam generating unit." See. 40 CFR part 51, 

Appendix Y. section V. 

" Suggested language - Continuous emission monitoring system" or "CEMS" means the equipment 

required by Ithis section | to sample. unalyTC, measure, and provide, by means of readings recorded at least 

once every 15 minutes (using an automated data acquisition and handling system (DAHS)). a permanent 

record of S02 or NOx emissions, other pollutant emissions, diluent, or stack gas volumetric flow rate. 

Suggested language - "Substitute hourly emission rates" or "substitute hourly emission values" meaas 

any hourly emission rates or values calculated in accordaiKc with the missing data substitution procedures 

of 40 CHR part 75. subpart D, where valid, quality a.ssured CEMS data for that hour are unavailable. 
a. Pounds Per Hour LimiLs, If the limit [in Table (cross-ref BART limit 

talile)|is expressed as a Ib/hr limit, owner/operator shall calculate average Ib/hr emissions 

over the appropriate averaging period, as follows: 

i. Limits with a 30-day averaging period: Emissions shall be calculated on a 

30-day rolling average basis. At the end of each boiler operating day, owner/operator 

shall calculate a new 30-day rolling average emission rate in Ib/hr from the arithmetic 

average of all valid and substitute hourly emission values from the CEMS for the most 

recent 30 boiler operating days 

ii. LimiLs with a 12-month averaging period: emissions shall be calculated 

on a 12-month rolling average basis. At the end of each month, owner/operator shall 

calculate a new 12-month rolling average emission rate in Ib/hr from the arithmetic 

average of all valid and substitute hourly emission values from the CEMS for the most 

recent 12 months, 

b. Tons Per Year Limits, If the limit [in Table (cross-ref BART limit table)]is 

expressed as a ton.s/yr limit, rolling 12-month total, total emissions in tons/yr shall be 

calculated on a i 2-month rolling basis. At the end of each month, owner/operator shall 

calculate a new 12-month emissions total, in tons/yr, using all valid and substitute hourly 

emission values from the CEMS for the most recent 12 months. 

2. Pounds Per Million Btu Limits 

For any hour in which fuel is combusted in the boiler, owner/operator shall 

calculate hourly average S02 and NOx concentrations in pounds per million Btu at the 

CEMS in accordance with the requirements of 40 CFR part 75. For any hour that valid, 

quality assured CEMS data are unavailable, emissions shall be calculated in accordance 

with the mis.sing data substitution procedures in 40 CFR part 75 subpart D. These houriy 

averages shall then be used to determine compliance in accordance with the particular 

limit's averaging period, as follows: 

a. Limits with a 3-hour averaging period: emissions shall be calculated on a 3-hour 

rolling average basis. At the end of each hour, owner/operator shall calculate a new 3-

hour average emission rate in Ib/MMBtu from the arithmetic average of the valid and 

substitute hourly emission rates from the CEMS for the most recent three hours. 

b. Limits with a 30-day averaging period: emis.sions shall be calculated on a 30-day 

rolling average basis. At the end of each boiler operating day, owner/operator shall 

calculate a new 30-day rolling average emission rate in Ib/MMBtu from the arithmetic 

average of all valid and substitute houriy emission rates from the CEMS for the most 

recent 30 boiler operating days. 

c. Limils with a 90-day averaging period: emissions shall be calculated on a 90-day 

rolling average basis. At the end of each boiler operating day. owner/operator shall 
calculate a new 90-day rolling average emission rate in Ib/MMBtu from the arithmetic 

average of all valid and substitute hourly emission rates from the CEMS for the most 

recent 90 boiler operating days. 

d. Limits with a 12-month averaging period: emissions shall be calculated on a 12-

month rolling average basis. At the end of each month, owner/operator shall calculate a 

new 12-month rolling average emission rate in Ib/MMBtu from the arithmetic average of 

all valid and substitute hourly emission rates from the CEMS for the most recent 12 

months. 

e. Limits with an annual calendar averaging period: emissions shall be calculated on 

a calendar year ba.sis. At the end of each calendar year, owner/operator shall calculate a 

new emission rate in Ib/MMBtu from the arithmetic average of all valid and substitute 

hourly emission rates from the CEMS for the preceding year. 
ENCLOSURE 3 

DRAFT COMPLIANCE DETERMINATION LANGUAGE FOR COLORADO 

BART LIMITS 

2/11/10 

I. Monitoring, Recordkeeping, and Reporting 

A, Definitions 

"BART unit" means any unit subject to a BART emission limit in Table 

"Boiler operating day" means any twenty-four-hour period between midnight and 

the following midnight during which any iliel is combusted at any time in a BART unit. 

"Continuous emission monitoring system" or "CEMS" means the equipment 

required by [this section] to sample, analyze, measure, and provide, by means of 

readings recorded at least once every 15 minutes (using an automated data acquisition 

and handling system (DAHS)), a permanent record of S02 or NOx emissions, other 

pollutant emissions, diluent, or stack gas volumetric flow rate. 

"Substitute hourly emission rates" or "substitute hourly emission values" means 

any hourly emission rates or values calculated in accordance with the missing data 

substitution procedures of 40 CFR part 75, subpart D, where valid, quality assured CEMS 

data for that hour are unavailable. 

B, Monitoring/Compliance Determination: S02 and NOx BART Limits 

At all times after the compliance deadline specified in [[specify sectionll. the 

owner/operator of each BART imit shall maintain, calibrate, and operate a CEMS, in fiill 

compliance with the requirements found at 40 CFR part 75, to accurately measure S02, 

NOx, diluent, and stack gas volumetric flow rate from each BART unit. The CEMS shall 

be used to determine compliance with the S02 and NOx BART emission limits for each 

BART unit. 

In determining compliance with the S02 and NOx BART limits, all periods of 

emissions shall be included, including startups, shutdovms, emergencies, and 

malfimctions. 

NOTE: Per section 302(k) of the CAA, BART limits must be met continuously. The 

BART limits section of the SIP and Reg. 3 need to state that the BART limits apply 

at all times, including periods of SSM. 

1. Pounds Per Hour And Tons Per Year Limits 

For any hour in which fiiel is combusted in the boiler, owner/operator shall 

calculate hourly S02 and NOx emissions in pounds at the CEMS in accordance with the 

monitoring procedures and requirements of 40 CFR part 75. In calculating hourly mass 
emissions and emissions rates, owner/operator shall use the conversion procedures 

specified in 40 CFR part 75, Appendix F. For any hour that valid, quality assured CEMS 

data are unavailable, emissions shall be calculated in accordance vn\h the missing data 

substitution procedures in 40 CFR part 75, subpart D. These hourly values shall then be 

used to determine compliance in accordance with the particuleu: limit's avereiging period, 

as follows: 

a. Pounds Per Hour Limits. If the limit [in Table ^(cross-ref BART limit 

table)]is expressed as a Ib/hr limit, owner/operator shall calculate average Ib/hr emissions 

over the appropriate averaging period, as follows: 

i. Limits with a 30-day averaging period: Emissions shall be calculated on a 

30-day rolling average basis. At the end of each boiler operating day, owner/operator 

shall calculate a new 30-day rolling average emission rate in Ib/hr fh>m the arithmetic 

average of all valid and substitute hourly emission values fi'om the CEMS for the most 

recent 30 boiler operating days 

ii. Limits with a 12-month averaging p)eriod: emissions shall be calculated 

on a 12-month rolling average basis. At the end of each month, owner/operator shall 

calculate a new 12-month rolling average emission rate in Ib/hr from the arithmetic 

average of all valid and substitute hourly emission values from the CEMS for the most 

recent 12 months. 

b. Tons Per Year Limits. If the limit (in Table (cross-ref BART limit table) jis 

expressed as a tons/yr limit, rolling 12-month total, total emissions in tons/yr shall be 

calculated on a 12-month rolling basis. At the end of each month, owner/operator shall 

calculate a new 12-month emissions total, in tons/yr, using all valid and substitute hourly 

emission values from the CEMS for the most recent 12 months. 

2. Pounds Per Million Btu Limits 

For any hour in which fiiel is combusted in the boiler, owner/operator shall 

calculate hourly average S02 and NOx concentrations in poimds per million Btu at the 

CEMS in accordance with the requirements of 40 CFR part 75. For any hour that valid, 

quality asstired CEMS data are unavailable, emissions shall be calculated in accordance 

with the missing data substitution procedures in 40 CFR part 75, subpart D. These hourly 

averages shall then be used to detennine compliance in accordance with the particular 

limit's averaging period, as follows: 

a. Limits with a 3-hour averaging period: emissions shall be calculated on a 3-hour 

rolling average basis. At the end of each hour, owner/operator shall calculate a new 3-

hour average emission rate in Ib/MMBtu from the arithmetic average of the valid and 

substitute hourly emission rates from the CEMS for the most recent three hoiu^. 

b. Limits with a 30-day averaging period: emissions shall be calculated on a 30-day 

rolling average basis. At the end of each boiler operating day, owner/operator shall 
calculate a new 30-day rolling average emission rate in Ib/MMBtu fix)m the arithmetic 

average of all valid and substitute hourly emission rates from the CEMS for the most 

recent 30 boiler operating days. 

c. Limits with a 90-day averaging period: emissions shall be calculated on a 90-day 

rolling average basis. At the end of each boiler operating day, owner/operator shall 

calculate a new 90-day rolling average emission rate in Ib/MMBtu fix)m the arithmetic 

average of all valid and substitute hourly emission rates from the CEMS for the most 

recent 90 boiler operating days. 

d. Limits with a 12-month averaging period: emissions shall be calculated on a 12-

month rolling average basis. At the end of each month, owner/operator shall calculate a 

new 12-month rolling average emission rate in Ib/MMBtu firom the arithmetic average of 

all valid and substitute hourly emission rates from the CEMS for the most recent 12 

months. 

e. Limits with an aimual calendar averaging period: emissions shall be calculated on 

a calendar year basis. At the end of each calendar year, owner/operator shall calculate a 

new emission rate in Ib/MMBtu from the arithmetic average of ail valid and substitute 

hourly emission rates from the CEMS for the preceding year. {[Need to address 

bubbled units.}} 

C. Monitoring/Compliance Determination: Particulate BART Limits 

1. EGU Particulate BART Limits. 

Compliance with the particulate BART emission limits for each EGU BART unit 

shall be determined from armual performance stack tests. Within 60 days of the 

compliance deadline specified in , and on at least an annual basis thereafter, the 

owner/operator of each EGU BART unit shall conduct a stack test on each unit to 

measure particulate emissions using EPA Method 5, 5B, 5D, or 17, as appropriate, in 40 

CFR part 60, Appendix A. A test shall consist of three runs, with each run at least 120 

minutes in duration and each run collecting a minimum sample of 60 dry standard cubic 

feet. 

In addition to annual stack tests, owner/operator shall monitor particulate 

emissions for compliance with the BART emission limits in accordance with the 

applicable Compliance Assurance Monitoring (CAM) plan developed and approved in 

accordance with 40 CFR part 64. 

2. CEMEX Particulate BART Limits. [[Need to address CEMEX particulate 

limits - 20% opacity and lb/ton of dry feed.}} 

D. Recordkeeping 

Owner/operator shall maintain the following records for at least five years: 
1. All CEMS data, stack test data, and data collected pursuant to the CAM plan, 

including the date, place, and time of sampling, measurement, or testing; parameters 

sampled, measured, or tested and results; the company, entity, or person that performed 

the testily, if applicable; and any field data sheets from testing. 

2. Records of quality assurance and quality control activities for emissions 

measuring systems including, but not limited to, any records required by 40 CFR Part 75. 

3. Records of all major maintenance activities conducted on emission imits, air 

pollution control equipment, and CEMS. 

4. Any other records required by 40 CFR parts 64 and 75. 

E. Reporting requirements 

Owner/operator shall submit quarterly excess emissions repKJrts no later than the 

30"' day following the end of each calendar quarter. Excess emissions means emissions 

that exceed the emissions limits specified in above. Owner/operator shall submit 

reports of any required performance stack tests for particulate matter, within 60 calendar 

days after completion of the test. Owner/operator shall also submit quarterly reports of 

any exceedances or excursions under the approved CAM plan, and steps taken to correct 

the exceedances or excursions, in accordance with 40 CFR 64.9(a). 

Owner/operator shall also submit quarterly CEMS performance reports, to include 

dates and duration of each period during which the CEMS was inoperative (except for 

zero and span adjustments and calibration checks), reason(s) why the CEMS was 

inoperative and steps taken to prevent recurrence, any periods for which missing data 

substitution procedures were used, any CEMS repairs or adjustments, and results of any 

CEMS performance tests required by 40 CFR part 75 (Relative Accuracy Test Audits, 

Relative Accuracy Audits, and Cylinder Gas Audits),