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Unite d State s Environmenta l Protectio n Agenc y Offic e o fAi rQualit y Plannin g an d Standard s Washingto n D C 2046 0 Stationar ySourc e Complianc e Serie s 

# Technica l Guideline : Alternativ e Procedure s fo r Reductio n an d Reportin g o f Metho d 9 Opacit y Reading s -J* . Specia l Repor t October ! 198 3P. 3

Thi s documen t ha s no t bee n formall yrelease d byEP Aan d shoul d no t b e construe d t o represen t Agenc y policy . I t i s bein g circulate d fo rcommen t o n it s technica l accurac yan d polic yimplications . I 

# Specia l Repor t 

# Technica l Guideline : Alternativ e Procedure s fo rReductio n an d Reportin g O fMetho d 9 Opacit yReading s Fina l Draf t Repor t

U.S . ENVIRONMENTA LPROTECTIO N AGENCY

Offic e o fAi ran d Radiatio n Offic e o fAi rQualit yPlannin g an d Standard s Stationar ySourc e Complianc e Divisio n Washington , D.C . 2046 0 Octobe r198 3P. 4

TABL E O F CONTENTS Pag e 

### Chapte r 1. 0 Introductio n 1 Chapte r 2. 0 Backgroun d 4 Chapte r 3. 0 Preferre d Method s fo r Tim e Exemptio n Regulation s 1 2

3. 1 Frequenc yCoun t Metho d 1 2 3. 2 Metho d 9 1 4 3. 3 Summar

yo fPreferre d Method s fo rTim e Exemptio n Regulation s 1 6 Chapte r4. 0 Preferre d Method s fo rIntermitten tEmissio n Source s 1 8

4. 1 Three-Minut e Averag e 1 8 4. 2 Frequenc yCoun t Metho d 1 9 4. 3 Summar

yo fPreferre d Method s fo rIntermitten tEmissio n Source s 1 9 4. 4 Stopwatc h Metho d 2 1 Chapte r5. 0 Evaluatio n o fShort-Ter m an d Nonaveragin g Opacit y

Readin g Method s 2 2 5. 1 Descriptio n o fReadin g Method s Use d durin g Intermitten tPlum e Fiel d Stud y2 3 5. 2 Intermitten t Emission s Fiel d Stud y2 3 5. 3 Fugitiv e Emission s Stud y2 8 5. 4 Definitio n o fIntermitten tEmission s 34 5. 5 Recommende

d Readin g Method s - Intermitten tEmission s 3 5 5. 6 Recommende

d Readin g Method s - Tim e Exemptio n Regulation s 3 6 5. 7 Accurac yo fth e Frequenc yCoun t Metho d - Al l Plum e Type s 4 0 Chapte r6. 0 Relativ e Stringenc yof-Reading/Dat a Reductio n Method s 46

6. 1 Procedur e fo rEvaluatin g th e Relativ e Stringenc yo fOpacit y4 7 Stan d ard/Rea d in g Metho d Combination s 6. 2 Assumption s Use d fo rRelativ e Stringenc yEvaluatio n 4 9 Chapte r7. 0 Summar yan d Majo rConclusion s 50 Appendi xAFedera l Register , Vol . 39 , No . 219 , Referenc e Metho d 9 A- l Appendi xB Alternativ e Method s fo rVisua l Determinatio n o fth e B- l

Opacit yo fEmission s fro m Stationar ySource s Appendi xC Summar

yo fOpacit yRegulation s (b yRegion ) C- 1

nP. 5

LIS TO F TABLE S Pag e Tabl e 1 Summar

yo fMetho d 9 Requirement s fo rVisua l 6 Determinatio n o fOpacit y Tabl e 2 Opacit yReadin g Metho d Specifie d i n Stat e Regulations , 9

Liste d byTyp e o fOpacit yEmission s Regulatio n Tabl e 3 Intermitten t Plum e Fiel d Stud y- Numbe ro fSix-Minut e 2 7

Dat a Set s b yPlum e Colo ran d Configuration , an d by Readin g Metho d Tabl e 4 Compariso n o fError s fo rDifferen t Opacit yReadin g 2 9

Method s fo rHighl yIntermitten t Plume s - 95t h Percentil e Tabl e 5 Between-Observe rPrecisio n fo rFugitiv e Emission s Dat a 3 2 (Aggregate-Tim e Method ) Tabl e 6 Between-Observe rPrecisio n fo rFugitiv e Emission s Dat a 3 3 (Opacit yAveragin g Method ) Tabl e 7 Erro rStandar d Deviation s b ySmok e Colo r3 7 fo rDifferen tAveragin g Time s Tabl e 8 Differenc e betwee n Observer s fo rFugitiv e Emission s 38

Dat a fo rDifferen t Averagin g Time s Tabl e 9 Dat a Set s Use d t o Evaluat e Frequenc yCoun tMetho d Accurac y4 3 Tabl e 1 0 Accurac yLevel s fo rFrequenc yCoun tMetho d 45 Tabl e 1 1 Relativ e Stringenc yAnalysi s o fIntermitten tFugitiv e 48

Emissio n Dat a

mP. 6

LIS T O F FIGURE S
Figur e 1 Exampl e Visibl e Emission s Repor t For m Figur e 2 Exampl e Dat a Reductio n Calculation s fo r

Frequenc yCoun t Metho d Figur e 3 Exampl e Stri p Char t - Extremel yRapi d Rise/Fal l Plum e Figur e 4 Exampl e Stri p Char t - Rapi d Rise/Fal l Plum e Figur e 5 Stri p Char t Ru n 9 - Slowl yChangin g Plum e Pag e 1 3 1 5 2 5 i 2 6 4 2

i vP. 7

1. 0 INTRODUCTION Buildin g o n prio rFederal , State , and loca l contro l agencylegislatio n an d experience , th e Clea n Ai rAct , as amende d i n 197 0 an d 1977 , authorize d a nationa l progra m o fai rpollutio n preventio n and control . Thi s progra m in - ! elude d nationa l ambien t ai rqualit ystandard s and Stat e Implementatio n Plan s ; (SIPs) ; emissio n standard s fo rmobil e sources ; fue l additiv e standards ; hazard ou s pollutan t standards ; and—-fo rth e firs t time—nationwide , uniform , tech - , nology-base d standard s o fperformanc e fo rne wan d modifie d stationar ysources. ] Th e standard s i n thi s latte rcategory , whic h ar e authorize d b ySectio n 11 1 of , th e Act , ar e commonl yreferre d t o as Ne wSourc e Performanc e Standard s (NSPS) . To suppor t thes e NSPS , referenc e tes tmethod s wer e promulgate d t o assur e consisten t an d accurat e measurement s o femissions . Referenc e Metho d 9—Visual ! i Determinatio n o fEmission s fro m Stationar ySources—provide s fo rth e determina; - tio n o fth e opacit yo femission s byqualifie d observers . Whe n Metho d 9 wa

s revise d an d repromu l gate d i n 1974 , th e procedur e o fdeterminin g averag e opacit y o f2 4 consecutiv e 15-secon d reading s (amountin g t o a six-minut e period ) wa s esftablished . However , th e Preambl e t o th e Metho d recognize d tha t thi s opacity averagin g approac h wa s no t appropriat e fo revaluatin g certai n source s o fpartic ulat e matte rwit h intermitten temission s o rfo renforcin g time-exemptio n regula tion s foun d i n man

ySIPs . Th e Preambl e als o indicate d tha talternativ e proce- ' dure s fo revaluatin g emission s fro m intermitten tsource s woul d b e investigated ^ Fiel d test s o fth e more commonl yused alternativ e opacit yreadin g method s wer e conducte d b yth e Stationar ySourc e Complianc e Divisio n o fEP Astartin g i n 1980 . Thi s guidelin e documen t provide s an evaluatio n o fth e dat a fro m thes e fiel d tests , an d th e relativ e performanc e o fth e thre e majo ralternativ e 

### 1P. 8

opacit yreadin g method s tested--th e frequenc ycoun t (o rtim e distribution ) method , th e stopwatc h method , an d averagin g o freading s fo rperiod s o fthre e minute s and less . Potentia l measuremen terror s fo rth e differen t method s ar e discusse d alon g wit h programmati capproache s fo rtakin g thes e error s int o consideratio n i n th e enforcemen t o fopacit ystandards . Recommendation s and detaile d procedure s ar e include d fo rus e o fthes e methods , wit h a discussio n o fth e circumstance s unde rwhic h eac h shoul d b e used . Thi s technica l guidelin e wa s prepare d t o provid e suppor t and guidanc e t o ai rpollutio n contro l agencyofficial s i n developin g method s and procedure s fo r us e i n determinin g complianc e o fstationar ysource s wit h opacit ystandard s an d rule s containin g tim e exemption s and/o rsource s wit h intermitten tvisibl e emissions . Thi s technica l guidelin e i s divide d int o th e followin g sections : Chapte r1. 0 - - Introduction . Chapte r2. 0 - - Background . Include s a brie fhistor yo fopacit y

regulations . Discusse s difference s betwee n Federa l an d Stat e opacit yregulation s an d readin g methods . Summarize s strength s o feac h approach . Chapte r3. 0 - - Descriptio n o fMethod s fo rTim e Exemptio n Regulations .

Describe s th e tw o recommended opacit yreadin g methods , frequenc ycoun t an d six-minut e averaging . Discusse s circumstance s wher e eac h shoul d b e used . Give s exampl e o fus e o fmetho d accurac yfo rfrequenc ycoun tmethods . Chapte r4. 0 —Descriptio n o fMethod s fo rIntermitten tEmissio n Sources .

Describe s th e tw o recommended opacit yreadin g methods , frequenc ycoun tan d three-minut e averaging . Discusse s circumstance s wher e eac h shoul d be used . Chapte r5. 0 - - Evaluatio n o fShort-Ter m an d Nonaveragin g Opacit y

Readin g Methods . Describe s thre e fiel d studies . Discussse s issue s surroundin g choic e o fmethod s pre sente d i n Chapter s 3. 0 an d 4.0 .P. 9

Chapte r6. 0 - - Relativ e Stringenc yo fReading/Dat a Reductio n Methods .

Discusse s wh

ythi s i s a concern . Describe s step s i n conductin g a stud yt o compare th e relativ e stringenc y o fdifferen t methods . Give s result s o frelativ e stringenc yanalysi s o fon e se to ftypica l opacit y readings . Chapte r7. 0 —Summar yan d Majo rConclusions . Appendi xA—Th e complet e tex to fth e Metho d 9 repromulgation ,

includin g th e Preamble . Appendi xB - - Alternativ e Method s fo rVisua l Determinatio n o fth e

Opacit yo fEmission s fro m Stationar ySources . Pre sent s detaile d procedure s i n forma to fregulations .P.1 0

... T ,....,,-. -

2. 0 BACKGROUN D Regulation s limitin g visibl e emission s wer e amon g th e firs t lega l tool s use d t o reduc e particulat e emission s fro mstationar ysources , an d thes e law s continu e t o pla yan importan t rol e i n moder n ai r pollutio n contro l efforts . Opacit yreading s take n b ytrained , certifie d observer s followin g prescribe d procedure s hav e prove d accurat e an d effectiv e fo r quickl yevaluatin g visibl e emission s and hav e bee n s o recognize d b ymos t courts . Opacit yregulation s and limitation s firs t wer e adopte d b yloca l contro l agencies , primaril yfo r boiler s and incinerators . T o accommodat e necessar yshor t period s o f excessiv e emission s fo r suc hoperation s a s soo t blowing , man yofithes e regulation s allowe d shor t period s abov e th e norma l emissio n limit . A s concer n shifte d t o othe r type s o f emissio n sources , thes e sam e tim e exemption s usuall y wer e kep t t o allo winfrequen t and mino r fluctuation s in proces s operations . A typica l "tim e exemption " regulatio n tha t wa s adopte d b yLo s Angele s i s a s follows :

" Aperso n shal l no t discharg e int o th e atmospher e froman yiw..
- sourc e o f emissio n whatsoeve r anyai r contaminan t fo r a perioc 1 o r period s aggregatin g mor e tha n thre e minute s i n anyon e hou r whic his : (a ) A s dar k o r darke r i n shad e a s tha t designate d a s No . 2 o n th e Ringelman n Chart , a s publishe d b yth e Unite d State s Burea u o f Mines , o r (b ) O f suc hopacit ya s t o obscur e a n observer' s vie wo f a degre e equa l t o o r greate r tha n doe s smok e describe d i n subsectio n (a ) o f thi s section. " Th e Clea n Ai r Act , Sectio n 11 0 require s tha t State s mus t hav e " a pla n whic h provide s fo r implementation , maintenance , an d enforcement " o f applicabl e ambien t ai r qualit ystandards . Stationar ysourc e emissio n standard s are include d a s par t o f al l Stat e Implementatio n Plan s (SIPs) , includin g visibl e emissio n standard s t o limi t particulat e emissions.-
- Mos t State s no t alread yhavin g regulations 

### 1 4 0 CFR , Par t 51 .P.1 1
, 1 l-.fl-- -

adopte d tim e exemption-typ e regulation s simila r t o th e Lo s Angele s example . EP A wa s designate d responsibilit yfo r ensurin g tha t State s di d i n fac t enforc e thei r regulation s an d maintai n clea n air . Th e Clea n Ai r Ac t Amendment s o f 197 0 and 197 7 als o provide d fo r EP At o se t emissio n limit s fo r certai n majo r ne wsources . A s Ne wSourc e Performanc e Standard s (NSPS ) wer e promulgate d b yEPA , tes t method s als o wer e promulgate d t o allo waccurat e and consisten t measuremen t o f differen t pollutan t emissions! . Metho d 9 fo r th e determinatio n o f visibl e emission s wa s firs t promulgate d o n Decembe r 23 , 1971 . Thi s firs t tes t metho d require d tha t a t leas t 2 5 reading s b e average d togethe r (eac hreadin g take n a t 15
- t o 30-secon d inter
vals) . Som e brie f requirement s fo r reade r positionin g and certificatio n wer e als o given . Metho d 9 wa s substantiall yexpande d and repromulgate d o n Novembe r 12 , 197 4 i n respons e t o th e cour t reman d o f th e Portlan d Cemen t Plan t NSP S (Portlan d Cemen t Associatio n v . Ruckelshaus) . Th e revise d Metho d 9 wa s muc hmor e specifi c abou t th e reade r positioning , th e dat a t o b e recorde d durin g a reading , th e dat a reductio n method , and th e conduc t o f th e reade r certificatio n and testin g program . Tabl e 1 summarize s th e majo r require
ment s o f th e revise d Metho d 9 . Th e introductio n t o th e revise d Metho d 9 describe d fiel d trial s tha t wer e i conducte d b

yEP At o establis hth e accurac yand precisio n o f Metho d 9 . Thes e test s gav e measuremen t error s fo r bot hblac k and whit e plume s a t tw o differen t levels , 99 % an d 95 % o f th e dat a sets . Th e introductio n furthe r state d tha t th e accurac yo f th e metho d ha d t o b e take n int o consideratio n whe n determinin g whethe r o r no t a violatio n ha d occurred . Th e Preambl e t o th e Novembe r 12, ! 197 4P.1 2

TABLE 1 . SUMMAR

YO F METHO D 9 REQUIREMENT

S FO R VISUALDETERMINATION O F OPACITY l Reade rposition/technique s Su n mus t b e i n a 140 ° secto rbehin d th e reader . Plum e shoul d be as perpendicula rt o reade rlin e o fsigh tas possible . Plum e mus t b e rea d wher e condense d wate rvapo ri s no tpresent , an d wher e th e plum e i s o fth e greates t opacity . Individua l opacit yobservation s ar e t o b e take n eac h 1 5 seconds , an d recorde d t o th e neares t5 % opacity . Dat a reductio n Twenty-fou rconsecutiv e 15-secon d reading s shal l b e average d (six-minut e averages) . Certificatio n

. Mus t rea d 2 5 differen t whit e an d 2 5 differen t blac k plume s consecutivel y withi n th e followin g erro rmargins .

. N o individua l readin g ma yb e of fb ymore tha n 15 % opacity .

. Th e overal l averag e erro rcanno texcee d 7.5 % opacit yfo reithe rblac k o rwhit e plumes .

. Certificatio n i s vali d fo ra perio d o fsi xmonths .

. Th e smok

e generato rmus tmee t give n specifications , whic h includ e calibratio n error , respons e time , zer o an d spa n drift , an d othe r requirements . 

### I A s repromulgate d o n Novembe r12 , 1974 .P.1 3 • | T| ";>!- ' "

amendmen t mentione d tha t Method* 9 (six-minut e average ) wa s no tcompatibl e wit h tim e exemption-typ e regulations , an d wa s no teffectiv e i n dealin g wit h inter mitten t emissions . Metho d 9 , then , ha s severa l importan tadvantage s and disadvantages : I t i s detaile d an d formall ypromulgated . I t include s opacit yobservatio n procedures , dat a reductio n methods , an d certificatio n requirements . I t i s consisten t wit h NSP S tha tlimi t opacit ybase d o n a six-minut e average . I t has supportin g dat a o n th e accurac yo fth e metho d whic h shoul d b e considere d byth e Agenc yi n determinin g possibl e violations . I t i s no t compatibl e wit h tim e exemptio n regulation s favore d b yman y States . I t doe s no t adequatel yevaluat e some intermitten t emissions . Unti l th e lat e 1970s , almos t al l Stat e an d loca l ai rpollutio n contro l i agencie s used a differen t opacit yreadin g method , calle d th e "frequenc ycount " o r"aggregate-time " method . Thi s metho d i s use d wit h tim e exemption-typ e regulations . I n contras t t o Metho d 9 , wher e 2 4 reading s ar e averaged , wit h th e frequenc ycoun t metho d eac h individua l 15-secon d readin g abov e th e opacit y! limi t i s counte d an d the n multiplie d by1 5 second s t o obtai n th e aggregat e time . I fth e tim e abov e th e opacit ystandar d exceed s th e tim e exemptio n perio d specifie d i n th e regulation , the n the * sourc e coul d b e considere d i n noncompli'ance . Fo rexample , th e previousl ycite d Lo s Angele s regulatio n allow s emission s o fthre e minute s pe rhou rgreate rtha n 40 % opacity . I fa 60-minut e readin g perio d include d fourtee n 15-secon d reading s abov e 40 % opacity , the n th e sourc e i s i n violatio n (1 4 reading s X1 5 seconds/readin g = 3-1/ 2 minutes. ) Administrativ e procedure s fo rtakin g measuremen terro rint o accoun tfo r th e frequenc ycoun t metho d var yamon g agencies , an d appea rt o be se t as a resul tP. M

o f experienc e wit hth e metho d rathe r tha n fro ma statistica l evaluatio n o f any specifi c fiel d study . On e agenc ywit ha 20 % opacit ylimi t an d three-minut e tim e exemption , fo r example , require s fou r minute s o f 30 % opacit yo r mor e befor e enforcemen t actio n i s taken . Startin g i n th e lat e 1970s , man yState s adopte d "Metho d 9 " b

yreferenc e int o thei r regulations. ^ However , man yo f thes e sam e States retaine d thei r tim e exemption-typ e regulation s eve n thoug ha six-minut e averagin g techniqu e a s i n Metho d 9 i s no t compatibl e wit ha two- , three- , o r four-minut e tim e exemption . Appendi xC i s a summar yo f Stat e opacityregulation s includin g specifie d readin g method s a s o f November , 1982.- ^ Thi s lates t studyo f Stat e opacit yre gulation s and method s indicate d increasin g adoptio n o f Metho d 9 , bu t i t als o showe d that , i n practice , State s wit htim e exemptio n regulation s di d no t us e Metho d 9' s specifie d dat a reductio n metho d (six-minute averaging) . Th e on e exceptio n t o thi s i s tha t State s wit ha six-minut e tim e exemptio n ofte n us e th e six-minut e averages . Th e firs t six-minut e readin g o f excess emission s account s fo r th e exemptio n period , th e secon d six-minut e readin g o f excess emission s establishe s th e violation . Tabl e 2 summarize s th e readin g metho d versu s typ e o f regulatio n use d i n th e States . Severa l differen t approaches/technique s fo r tryin g t o fi t Metho d 9 t o tim e exemptio n regulation s hav e bee n use d o n a n informa l basis . Thes e includ e th e following :
1Twenty-thre e state s a s o f Novembe r 17 , 1982 . 2 Take n f*-o

msurve yrepor t prepare d fo r EP Ab yPacifi c Environmenta l Services , Inc . title d "Opacit yRegulations : Summar yo f Regulation s and Rulemakin g Status, " Februar y18 , 1983 .•'•ITH ! P.1 5

TABL E 2 . OPACIT Y READIN GMETHO D SPECIFIE D INSTAT E REGULATIONS ,

LISTE D BY TYP E O F OPACIT Y EMISSIO NREGULATION 1

Opacit yReadin g Metho d Specifie d i n Regulatio n Metho d 9 Othe r Method ' N o Metho d Specifie d

TOTAL 2 

# 1 1Fro mPacifi c Environment ; i 1 Numbe r o f State s wit hEac hTyp e o f Emissio n Regulatio n

Averag e 1 1 1 8 2 0 ' ' ' " ! Tim e Exemption i 6 minutes/hour : 51 Othe r tim e periods : 7

1 4 ! 1 6 '< 3 2 i l Services , Inc . repor t date d Februar y18 . 19^3 . Include s 5 0 States , Puert o Rico , and th e Distric t o f Columbia .P.1 6

. Pic k ou tth e highes t 15-secon d readin g abov e th e standar d require d fo rth e tim e exemption , and the n averag e th e remainin g 2 4 consecutiv e readings .

. Averag e fo ra tim e perio d o fsi xminute s + tim e exemptio n perio d (tha t is , fo ra three-minut e tim e exemption , averag e nine-minut e readings ; i fan yaverag e i s abov e standard , the n i ti s a violation) .

. Us e Method 9 fo rreade rpositionin g an d certification , bu tus e th e standar d frequenc ycoun t metho d fo rdat a reductio n (favore d bymos t States) .

. Averag e six-minut e readings , an d us e on e excessiv e six-minut e readin g fo rtim e exemptio n (regardles s o ftime) ; the n secon d six-minut e averag e above th e limi t establishe s th e violation . I n summary , man

yState s ar e attemptin g t o formaliz e thei rreadin g an d certificatio n procedure s whil e retainin g tim e exemption-typ e regulations . Th e frequenc ycoun t metho d o freadin g opacit yi s stil l widel yuse d byStates , and i t als o has bot h advantage s and disadvantages :

. Th e metho d i s compatibl e wit h tim e exemptio n regulations .

. Althoug h widel yused , thi s metho d (a tleas t th e dat a reductio n part ) i s rarel yinclude d i n th e regulations .

. Frequenc ycoun t metho d and tim e exemptio n regulation s ar e effectiv e tool s i n limitin g excessiv e intermitten temissions .

. Unti l thi s curren t study , th e metho d di d no thav e an establishe d measure o faccurac ytha t coul d b e used i n determinin g whe n t o tak e enforcemen t action . Th e EP Aand Stat e o rloca l official s fac e severa l problem s i n tryin g t o enforc e SI P opacit yregulations . Issue s whic h ma yaris e an d requir e resolutio n includ e th e following :

. I f"Metho d 9 " i s specifie d i n th e SI P bu t ther e ar e tim e exemptio n regulations , wha t dat a reductio n metho d shoul d b e used ?

. I fth e frequenc ycoun t metho d o freadin g an d dat a reductio n i s used , wha t measuremen t erro rshoul d b e use d t o determin e a violation ?

. Fo rintermitten temissio n sources , wha treadin g metho d shoul d b e used ? Thi s technica l guidelin e documen ti s intende d t o provid e suppor t t o ai r 

### 10P.1 7

pollutio n contro l agencyofficial s i n resolvin g question s abou treadin g methods , measuremen t error , an d dat a reductio n methods . Preferre d method s ar e presente d i n th e followin g chapter s alon g wit h recommendation s as t o thei rapplicatio n t o variou s type s o fvisibl e emissions . Documentatio n o fmeasuremen terro ran d technique s fo rtakin g int o consideratio n measuremen terro rar e described .



### 1 1P.1 8

3. 0 PREFERRE D METHOD S FO R TIM E EXEMPTIO NREGULATION S 3. 1 Frequenc yCoun t Metho d

Th e opacit yreadin g metho d o f choic e fo r us e wit htim e exemptio n regu lation s i s basicall ya modificatio n o f Metho d 9 , and i t i s known a s th e frequenc y coun t method . Reade r positioning , plum e observatio n procedures , dat a recording , an d certificatio n requirement s are identica l t o Metho d 9 . Th e onl ydifferenc e occur s i n dat a reductio n and th e relate d accurac yo f thi s modifie d metho d tha t shoul d b e considere d i n determin g whethe r t o procee d wit henforcemen t actions . Th e dat a reductio n metho d i s t o coun t eac h15-secon d readin g abov e th e standard , and multipl yb y1 5 seconds . I f tha t tim e exceed s th e tim e exemptio n specifie d i n th e opacit yregulation , the n a violatio n ma yhav e occurred . Figur e 1 i s a n exampl e o f a complete d opacit yreadin g form . A s par t o f th e EP Aevaluatio n o f alternativ e opacit ymethods , 1,88 0 six
minut e dat a set s wer e evaluate d usin g th e frequenc ycoun t metho d o f dat a re duction . Al l dat a set s wer e o f plume s wher e simultaneou s tiansmissomete r (opacit ymeter ) value s and observe r reading s coul d b e compared . Th e differ
ence s i n th e transmissomete r and observe r reading s giv e th e accurac yo f th e frequenc ycoun t method , whic hshoul d b e considere d prio r t o takin g enforcemen t action . Acombinatio n o f opacit yerro r fo r eac hindividua l 15-secon d readin g plu s a tim e erro r fo r eac hsi xminute s o f readin g wa s chosen. 1 Th e actua l amoun t o f opacit yerro r an d tim e erro r wa s determine d fro mth e 1,88 0 dat a sets . Statistica l analysi s o f th e dat a set s reveale d th e followin g information :
1 Se e Sectio n 5. 5 fo r a furthe r discussio n o f thi s choic e o f th e typ e o f erro r margin . 

### 12P.1 9 T'' ' FIGUR E 1 Exampl e Visibl e Emission s Repor t For m

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### 13P.2 0

. 99 % o fdat a set s showed n o positiv e bias 1 whe n a 10 % opacit y buffe ran d on e minute/six-minut e readin g buffe rwer e used .

. 95 % o fdat a set s showed n o positiv e bia s whe n a 10 % opacit ybuffe r an d 1 5 seconds/six-minut e readin g buffe rwer e used .

. 85 % o fdat a set s showed n o positiv e bia s whe n a 5 % opacit ybuffe r an d 1 5 seconds/six-minut e readin g buffe rwer e used . Figur e 2 show

s a n exampl e o fho

wt o us e th e frequenc ycoun tdat a reductio n metho d plu s erro rmargins . Thi s exampl e use s th e 85t h percentil e erro rmargin s describe d above . 3. 2 Metho d 9 Metho d 9 shoul d no t b e used wit h tim e exemption-typ e regulation s unles s ther e i s a six-minut e pe rhou rtim e exemptio n and Metho d 9 i s specifie d i n th e regulation s as th e readin g metho d t o be used . A s o fNovember , 1982 , Vermon t Virginia , Ohio , Louisiana , an d Nort h Dakot a woul d mee tthes e requirements . Whe n usin g Method 9 wit h a six-minut e pe rhou rtim e exemptio n regulation , tw o six minut e average s abov e th e standar d woul d b e require d fo ra violation ; th e firs t woul d b e fo rth e tim e exemptio n period , and th e secon d woul d documen t th e viola - tion . Th e accurac yo fth e six-minut e averagin g techniqu e shoul d b e considere d befor e an yenforcemen t actio n i s taken . Th e tw o preferre d method s fo rtim e ex emption-typ e regulations , th e frequenc ycoun t metho d an d Metho d 9 , ar e summarize d i n Sectio n 3.3 .



## 1"N o positiv e bias " mean s tha t th e time th e observe r rea dth e plume a t >20 % opacit y

wa s les s tha nth e time th e transmissomete r rea d>20 % opacity .


### 1 4P.2 1

FIGUR E 2 Exampl e Dat a Reductio n Calculation s fo rFrequenc yCoun tMetho d 1 Applicabl e regulation : Emission s fro m an ywood-fire d boile rshal l no tequa l o rexcee d 40 % opacit yexcep t fo rthre e minute s pe rhour . 

### Dat a Set : TIME

9:1 0 

### 1 1 1 2 1 3 1 4 9:1 5 

### 0

3 5 3 5 5 0 7 0 6 5 60 1/ 4 4 0 3 5 60 6 5 6 5 5 0 1/ 2 4 0 4 5 6 5 6 0 6 5 4 5 3/ 4 4 0 4 0 6 5 6 5 60 5 0 Buffer s use d fo r85

% accurac ylevel : 5 % opacit yfo reac h 15-secon d readin g '. Extr a 1 5 second s o fexcessiv e emission s pe rsi xminute s o freadin g Opacit y(actua l valu e rea d minu s 5 % opacity ) # Reading s Minute s Abov e Limi t 30% 35% 3 4 40 % 45 % 50 % 55 % 60 % 65 % 2 3 0 4 7 • 1 Aggregat e tim

e above standard Amoun t o f tim

e allowedabove standard= 3 minute s + extr a 1 5 second s Tim e exemptio n + erro rmargi n i n thi s dat a se texceede d by 

### 1 - 4 - 3 - 1 1/ 2 3/ 4 1 -3/ 4 

### 1/ 4 -1/ 4 -1/ 4 i 

### minut e
Fro m exampl e opacit yreadin g i n Figur e 1 . Onl yth e firs tsi xminute s o fth e reading s ar e used i n thes e sampl e calculations . I n rea l observations , th e t si xminute s wit h th e highes temission s woul d b e chose n fo rinitia l calculations , the n th e nex t highes t si xminute s (i fnecessary) , and so o n unti l eithe ra i violatio n i s demonstrate d o ral l dat a ha s bee n evaluate d and complianc e shown . 

### 15P.2 2

3. 3 Summar

yo fPreferre d Method s fo rTim e Exemptio n Regulation s Frequenc yCoun t Metho d 1 Applicabilit y

. Al l Stat e I regulation s ^ tim e exemptio n an d Metho d 9 i s specifie d i n th e regulation s Al l Stat e Implementatio n Pla n (SIP ) source s t o whic h tim e exemptio n regulation s apply , excep t wher e th e regulation s hav e a six-minute/hou r Description :

. Modificatio n o fMetho d 9 , wit h onl yth e dat a reductio n ste p an d associ ate d accurac yleve l differing . Eac h 15-secon d readin g abov e th e appli cabl e standard s i s counte d and the n multiplie d b y1 5 seconds . Violatio n occur s whe n th e tim e abov e th e standar d exceed s th e tim e exemptio n i n th e regulation , takin g int o accoun tth e accurac yo fth e method . Tes t Dat a o n Accurac yo fMethod :

. 99 % o fdat a set s showed n o positiv e bia s wit h 10 % opacit ybuffe r an d on e minute/six-minut e readin g buffer .

. 95 % o fdat a set s showed n o positiv e bia s wit h 10 % opacit ybuffe r an d 1 5 seconds/six-minut e readin g buffer .

. 85 % o fdat a set s showed n o positiv e bia s wit h 5 % opacit ybuffe r an d 1 5 seconds/six-minut e readin g buffer . Referenc e Metho d 9-

? Applicability :

. SI P source s t o whic h a six-minute/hou rtim e "exemptio n regulatio n applie s an d Metho d 9 i s specifie d i n th e SI P as th e require d method . Description :

. Six-minut e average s ar e calculated . Tw o six-minut e average s abov e th e standar d i n a 60-minut e perio d ar e require d fo ra violation . Th e accurac yo fth e metho d shoul d b e considere d befor e takin g enforcemen t action .
1 Se e Appendi xB fo ra detaile d procedure , 2 See Appendi xAfo ra detaile d procedure . 

### 16P.2 3

- . • r-,.,- r p.,, -

Tes t Dat a o n Accurac yo fMethod :

. 95 % o fdat a set s ha

d n o positiv e bia s i f5 % opacit ywa

s subtracte d fro m six-minut e average .

. 99 % o fdat a set s ha

d n o positiv e bia s i f7.5 % opacit ywa s subtracted , fro m six-minut e average .



### 17P.2 4

4. 0 PREFERRE D METHOD S FO R INTERMITTEN T EMISSIO NSOURCE S Som e type s o f industria l and commercia l processe s are cyclica l an d emi t larg e amount s o f visibl e an d particulat e emission s fo r shor t period s o f time , intersperse d wit hlon g period s o f minima l o r n o emissions . Som e example s o f suc hoperation s woul d includ e soo t blowin g o f boilers , pushin g operation s a t cok e ovens , and pourin g operation s a t foundries . Thes e source s o f intermitten t emission s ca n b e ver ysignifican t fro ma n ai r pollutio n standpoint . I t i s clearl ydesirabl e t o b e abl e t o measur e thes e emission s visuall yand t o limi t the mb yregulation . Th e six-minut e averagin g tim e specifie d i n Metho d 9 i s appropriat e fo r continuou s o r nearl ycontinuou s emissio n sources , bu t no t fo r intermitten t sources . I f th e six-minut e averagin g provisio n o f Metho d 9 i s applie d t o emissio n plume s tha t ar e characterize d b yintermitten t opacit ypeaks , rathe r tha n a sustaine d elevate d opacit ylevel , i t migh t b e impossibl e t o cit e a violatio n becaus e th e pea k opacit yreading s (a t 15-secon d intervals ) woul d b e offse t b

yth e lowe r baselin e opacit yvalue s ove r th e averagin g period . Th e Preambl e t o th e repromulgatio n o f Metho d 9 (Novembe r 12 , 1974 ) indicate d tha t Metho d 9 wa s no t abl e t o evaluat e intermitten t emission s adequately , an d tha t othe r alternativ e readin g method s woul d b e investigated . Thes e studie s hav e bee n completed , an d tw o alternativ e method s are presente d here . I t shoul d b e note d tha t thes e alternativ e method s ma yno t b e adequat e fo r evaluatin g extremel y short-ter memission s suc ha s thos e a t cok e ovens . Intermitten t emission s ar e define d a s emission s abov e th e standar d fo r les s tha n si xcontinuou s minutes . 4. 1 Three-Minut e Averag e Thi s metho d woul d b e use d o n thos e SI P source s wit hintermitten t emission s wher e th e emissio n regulation s d o no t hav e tim e exemptions . Al l provision s o f 1 8p , - -jur
Metho d 9 ar e followe d excep t fo rth e dat a reductio n perio d an d th e associated ! accurac yo fth e method . Twelv e consecutiv e 15-secon d reading s ar e t o b e averaged , rathe rtha n th e 2 4 specifie d i n Metho d 9 . Th e accurac yo fthree-minut e averagin g wa s establishe d byth e studie s reference d i n Sectio n 5.1 . O fth e 1,17 2 six-minut e dat a set s (eac h broke n int o tw o three-minut e dat a set s fo ra tota l o f2,34 4 dat a sets) :

. 95 % o fth e dat a set s showed n o positiv e bia s whe n 11.8 % opacit ywas subtracte d fro m th e observer' s three-minut e averages. 1

. 85 % o fth e dat a set s showed n o positiv e bia s whe n 7.5 % opacit ywa s subtracte d fro m th e observer' s three-minut e averages . 4. 2 Frequenc yCoun t Metho d

Th e frequenc ycoun t metho d fo rintermitten t emission s i s identica l t o tha t describe d i n Sectio n 3.1 . Th e frequenc ycoun t metho d i s t o b e use d o n al l intermitten t emissio n source s wher e th e applicabl e emissio n regulation s ar e o fth e tim e exemptio n type . Th e accurac yo fth e frequenc ycoun tmetho d i s th e sam

e a s tha t describe d i n Sectio n 3.1 . Th e tw o recommended method s fo rintermitten t source s ar e summarize d i n Sectio n 4. 3 an d describe d i n more detai l i n Appendi xB . Th e majo rissue s considere d an d othe ralternativ e method s evaluate d ar e discusse d i n detai l i n Chapte r5.0 . 4. 3 Summar

yo fPreferre d Method s for*Intermitten t Emissio n Source s Definitio n o fintermitten t emissions : Emission s abov e th e opacit y standar d tha t las t fo rles s tha n si xconsecutiv e minutes .


### 1 (Observe ropacit y- 11.8 % opacity ) £transmissomete ropacit yfo r95 % o f three-minut e averages . 

### 1 9P.2 6

Three-Minut e Averagin g Metho d Applicability :

. Al l Stat e Implementatio n Pla n (SIP ) source s no tsubjec tt o tim e exemptio n regulations . T

o b e used whe n emission s fro m suc h source s ar e intermitten t i n nature . Description :

. Identica l t o Metho d 9 , excep t tha tonl ytwelv e 15-secon d reading s take n ove ra three-minut e perio d ar e averaged . Tes t Dat a o n Accurac yo fMethod :

. 85 % o fdat a sets : n o positiv e bia s i f7.5 % opacit yi s subtracte d fro m th e three-minut e average .

. 95 % o fdat a sets : n o positiv e bia s i f11.8 % opacit yi s subtracte d fro m th e three-minut e average . Frequenc yCoun t Metho d Applicability :

. Al l SI P source s t o whic h tim e exemptio n regulation s apply . Description :

. Mino rmodificatio n o fMetho d 9 , wit h onl yth e dat a reductio n ste p an d associate d accurac yleve l differing . Eac h 15-secon d readin g abov e th e applicabl e standar d is.counte d an d the n multiplie d by1 5 seconds . Violatio n occur s whe n th e tim e abov e th e standar d exceed s th e tim e exemptio n i n th e regulation , takin g int o accoun t th e accurac yo fth e method . Tes t Dat a o n Accurac yo fMethod :

. 85 % o fdat a sets : 5

% opacit ysubtracte d fro m eac h 15-secon d readin g an d additiona l 1 5 second s abov e standar d adde d t o eac h six-minut e readin g resulte d i n n o positiv e bia s (85 % o freading s wit h thes e buffer s showed les s tim e abov e standar d tha n transmissometer) .

. 95 % o fdat a sets : 10 % opacit ysubtracte d fro m each . 15-secon d readin g an d additiona l 1 5 second s abov e standar d adde d t o eac h six-minut e readin g resulte d i n n o positiv e bias .

. 99 % o fdat a sets : 10 % opacit ysubtracte d fro m eac h 15-secon d readin g an d additiona l on e minut e abov e standar d adde d t o eac h six-minut e readin g resulte d i n n o positiv e bias . 2 0,; n... ,

4. 4 Stopwatc hMetho d

Th e stopwatc hmetho di s no t recommende da s a genera l methodfo r inte r mitten t emission s becaus e i t doe s no t easil y len ditsel f t o factorin g i na h i erro r buffe r fo r opacit y (se e Sectio n5.2) , althoug hi t ha s a nerro r margi n fo r time comparabl e t o tha t o f th e frequenc y coun t method . However , th e . stopwatc hmetho dha s bee nan dcanb e use

deffectivel y

for measurin g highl y ! intermitten t emissions , provide da nappropriat e erro r margi ni s included . Th e accurac y

o f th e stopwatc hmetho dwa s determine di na fiel dtes t an di s presente dinSectio n5.2 .



### 2 1P.2 8

5. 0 EVALUATIO NO F SHORT-TER MAN D NONAVERAGIN GOPACIT Y READIN GMETHOD S Th e studie s describe d her e wer e intende d t o accomplis htw o importan t objec
tives : 1 ) t o evaluat e differen t method s fo r readin g intermitten t plumes , an d 2 ) t o determin e th e accurac yo f th e frequenc ycoun t metho d fo r al l plum e types . Anumbe r o f differen t opacit yreadin g method s wer e examine d fo r evaluatin g intermitten t plumes . Tw o method s use d fo r intermitten t emission s b yStat e an d loca l ai r pollutio n agencies--th e stopwatc hmetho d and th e frequenc ycoun t method
—wer e evaluated , a s wel l a s short-ter maveragin g (les s tha n si xmin
utes ) fo r varyin g length s o f time . Th e frequenc ycoun t method , whic hi s commonl yuse d b yStat e and loca l agencies , ha s bee n describe d i n previou s sections . I t i s identica l t o Metho d 9 , excep t fo r th e dat a reductio n ste p an d associate d metho d accuracy . I t i s mos t ofte n use d wit htim e exemptio n regulations . Th e stopwatc hmetho d i s use d b ya fe wagencies , primaril yfo r sourc e categorie s wher e emission s ar e highl yintermitten t (suc ha s c.-k? r. •!>*!•• ' , T r thi s method , tw o stopwatche s ar e normall yuse d (o r a stopwatc han d a watc hwit h swee p secon d hand) . On e stopwatc ho r watc hi s use d t o recor d th e tim e o f th e entir e reading . Th e othe r stopwatc hi s use d t o kee p a runnin g tota l o f th e tim e th e emission s unde r observatio n excee d th e opacft ystandard . A s th e emissio n rise s abov e th e standard , th e stopwatc hi s started . When emission s fal l belo wth e standard , th e stopwatc hi s stopped . Thi s proces s i s repeate d fo r th e entir e readin g perio d a s th e plum e opacit yrise s abov e an d fall s belo w th e standard . Th e tota l tim e emission s wer e recorde d abov e th e standar d i s the n compare d t o th e tim e exemptio n perio d allowe d i n th e applicabl e regulation . Th e fina l metho d evaluate d wa s short-ter m averaging . One- , two- , an d three-minut e average s wer e examined . Th e sam e dat a bas e o f 15-secon d reading s 2 2. , . ,,. J- , ,. . „-, ,

wa s use d t o evaluat e th e frequenc ycoun tand averagin g dat a reductio n method,s . Al l thre e method s us e th e Metho d 9 criteri a fo rreade rpositioning . Th e thre e method s ar e summarize d i n Sectio n 5.1 . 5. 1 Descriptio n o fReadin g Method s Use d durin g Intermitten tPlum e Fiel d Stud y i Frequenc yCoun tMetho d 1

. Reade rpositioning : sam e as Metho d 9 , Sectio n 2. 1 (su n i n bac k 140 P sector , plum e a t righ t angle s t o reader , etc.) .

. Dat a recording : same as Metho d 9 , Section s 2. 3 an d 2. 5 (reading s take n an d recorde d eac h 1 5 second s t o neares t 5 % opacity) . '

. Dat a reduction : eac h 15-secon d readin g abov e th e 20 % opacit yleve l i s counte d i n a six-minut e dat a set , an d the n multiplie d by0.2 5 t o determin e th e minutes/six-minut e readin g abov e 20 % opacity . j Stopwatc h Metho d

. Reade rpositioning : sam e as Metho d 9 , Sectio n 2.1 . i

. Dat a recording : stopwatc h i s used t o accumulat e tim e plum e appear s t o be ove r20 % opacit ydurin g th e six-minut e dat a set . Th e stopwatc h i s turne d o n whe n th e plum e i s greate rtha n 20% , an d turne d of fwhe n th e plum e i s belo w20% .

. Dat a reduction : tim e i s rea d of fstopwatc h a tth e en d o feac h six-minut e dat a set . Short-Ter m Averaging l

. Reade rpositioning : sam e as Metho d .9 , Sectio n 2.1 .

. Dat a recording : same a s Metho d 9 , Section s 2. 3 an d 2.5 .

. Dat a reduction : 15-secon d reading s average d ove r1 , 2 , an d 3 minutes . 5. 2 Intermitten t Emission s Fiel d Stud y

Extensiv e fiel d testin g wa s conducte d t o compare thes e thre e method s durin g th e wee k

o fMa y19-23 , 198 0 a t Researc h Triangl e Par k (RTP) , Nort h Carolina . Twelv e participant s observe d fo ra tota l o f1,17 2 six-minut e peribd s 

## I Sam e rawdat a set s o f15-secon d reading s ove rsi xminute s wer e use d 23P.3 0

durin g th e five-da ytest . Th e participants , al l recentl ycertifie d visibl e emissio n observers , had fro m les s tha n on e t o 1 2 year s o fexperienc e i n readin g opacity . Durin g th e test , the yobserve d bot h blac k an d whit e plumes . Rapidl ychangin g plume s were examine d i n th e RT P fiel d test . Th e smok e generato ruse d t o generat e thes e plume s me t al l Metho d 9 criteria , and , i n addition , wa

s modifie d t o permi t more rapi d chang e i n plum e opacit ytha n i s normall ypossibl e wit h th e typ e o fsmok e generato ruse d i n qualifyin g Metho d 9 observers . Example s o fth e tw o plum e type s used fo rth e stud yar e shown i n Figure s 3 an d 4 . Th e extremel yrapidl yrisin g plum e shown i n Figur e 3 change d fro m 10 % opacit yt o 60

% opacit yi n onl y1. 5 seconds . Th e plum e ris e i n Figur e 4 wa s somewha

t slowe rbu t stil l ver yrapid—th e opacit yincrease d fro m 10 % t o 50 % i n 2 4 seconds . Betwee n on e an d thre e plum e rise/fal l cycle s occurre d durin g eac h six-minut e dat a set . Th e da ybefor e startin g th e fiel d experiment , al l participant s wer e shown prac tic e plume s an d the n certifie d b yMetho d 9 criteria . I n addition , th e reader s wer e instructe d i n th e operatio n o fa stopwatc h and ho wt o rea d an d recor d data . Al l ob server s wer e certifie d durin g standar d Metho d 9 smok e readin g certificatio n tests . Hal fo fth e reader s wer e provide d wit h stopwatches . Simultaneou s reading s wer e obtaine d durin g eac h ru n wit h si xreader s usin g th e stopwatc h an d si x reader s usin g th e frequenc ycoun t metho d o freading. 1 Eac h reade rwa s require d t o rea d eithe rbyth e stopwatc h metho d o rfrequenc ycoun tmetho d durin g eac h run . Every10-1 5 dat a sets , th e stopwatche s wer e give n t o thos e wh o had bee n readin g wit h th e frequenc ycoun tmethod , so tha teac h reade rha d abou tequa l tim e readin g wit h th e stopwatc h an d frequenc ycoun t methods . Th e numbe ro fdat a set s b ycolor , readin g method , an d plum e configuratio n ar e give n i n Table . 3 . 7 . • Th e "frequenc ycount " dat a was use d a s th e rawdat a fo rshort-ter m averagin g also . Bot h th e frequenc ycoun t metho d an d Metho d 9 us e discret e observation s made eac h 1 5 second s t o th e neares t 5 % opacity ; onl yth e dat a reductio n ste p varies .

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, -"T" " 1 Minute 2 5h«-2 4 Seconds-*- ! 2 6P.3 3

-

1 2 3 4 " " ' " "' ~" ~ ' " " ""'• " " ••• - »r--.-|;--| T 7

TABLE 3 . INTERMITTEN TPLUM E FIEL D STUDYl . NUMBE R O F SIX-MINUT E DAT

ASET S B YPLUM E COLO R AN D CONFIGURATION , AN D B YREADING METHO

D Plum e Colo r Readin g Method/P I um e Configuratio n Blac k Whit e Frequenc yCount ? Extrem e rapi d rise 3 12 0 180 , Rapi d rise* * 12 1 173 Stopwatc h Method Extrem e rapi d ris e 12 0 179 ; Rapi d ris e 11 1 16 8 TOTA L472 700 ;
t Conducte d Ma

y19-23 , 198 0 i n Researc h Triangl e Park , NC . Discret e 15-secon d reading s taken . Dat a reductio n wa s done i n severa l ways fo rth e same data—frequenc ycoun tan d averagin g fo rdifferen t length s o f1 time .
i Rise/fal l o f50

% opacit yi n 1. 5 seconds . Rise/fal l o f40

% opacit yi n 10-1 2 seconds .

2 7

••..: . 1P.3 4

Weathe rand backgroun d condition s wer e generall yver ygood durin g th e fiel d trial. * Gree n tree s wer e use d fo rbackgroun d o fwhit e plumes , wit h blu e skyuse d fo rblac k

plumes . Th e tes t result s fo rth e thre e differen t readin g an d dat a reductio n method s ar e presente d i n Tabl e 4 . Thes e result s ar e give n i n 95t h percentile s fo r compariso n purposes . Fo rth e stopwatc h method , th e erro ri s give n i n minute s only . Conceivably , a n erro rmargi n consistin g o fa specifie d opacit yleve l plu s a tim e coul d hav e bee n determine d i fth e tes tha d bee n se t u p fo rit . Fo rexample , a 10 % opacit y erro rcoul d have bee n selecte d befor e th e tes t an d the n th e correspondin g tim e erro rdetermine d byinstructin g th e participant s t o includ e onl yth e tim e whe n th e plum e appeare d t o b e equa l t o o rgreate rtha n 30 % opacit y(20 % + 10 % buffer) . Th e choic e wa

s made t o us e onl ya tim e erro rfo rsimplicity . Th e error s fo rshort-ter m average s ar e give n i n percen topacity . Th e frequenc ycoun t metho d erro ri s give n as a combinatio n o fopacit yerro ran d tim e error . (Se e Sectio n 5. 6 fo ra furthe rdiscussio n o fth e us e o fthi s combination. ) 5. 3 Fugitiv e Emission s Stud y

Visibl e emissio n observatio n dat a previousl ytake n a t severa l source s wit h fugitiv e emissions l durin g studie s conducte d byEP Afo rothe rpurpose s wer e als o compile d an d analyzed . The.purpos e o fthi s par to fth e stud ywas t o determin e i fobserve rerro rwhe n evaluatin g fugitiv e emissio n source s unde r actua l fiel d condition s woul d be differen t fro m th e erro rassociate d wit h th e smok e generato rtests . However , i n th e cas e o findustria l proces s fugitiv e sources , n o tru e opacit ymeasuremen t i s availabl e (i.e. , n o transmissomete r T "Fugitiv e emissions " ar e define d a s thos e emission s tha td o no tcom e fro m a stack , an d woul d includ e emission s fro m roo fmonitors , ope n doorways , roc k crushers , etc . 2 8P.3 5

TABLE 4 . COMPARISO N O F ERROR S FO R DIFFEREN

TOPACIT

YREADING METHOD

S FO R HIGHL YINTERMITTENTPLUMES l (95t h PERCENTILE2) Frequenc yCoun t Metho d Blac k Smoke : 5

% opacity , 0.2 5 minutes/six-minut e readin g Whit e Smoke : 5

% opacity , 0.5 0 minutes/six-minut e readin g Stopwatc h Metho d Blac k Smoke : 1. 0 minutes/si xminute s Whit e Smoke : 2. 1 minutes/si xminute s Short-Ter m Averagin g Method 3 

### One-minut

eaverag e Blac k Smoke : 7.2 % opacit y Whit e Smoke : 15.0 % opacit y 

### Two-minut

eaverag e Blac k Smoke : 5.6 % opacit y Whit e Smoke : 12.2 % opacit y Three-minut e averag e Blac k Smoke : 4.8 % opacit y Whit e Smoke : 11.8 % opacit y



# r Based o n fiel d stud yconducte d Ma y19-23 , 198 0 i n Researc h Triangl e Park , NC . I 95 % o fth e dat a set s hav e les s tha n th e indicate d error . Use o fthi s percent i l e i s fo rcompariso n purpose s only , an d doe s no tconstitut e a recommendatio n o faccurac yleve l fo rcomplianc e purposes . ! 3 ; Th e sam e rawdat a se t o f15-secon d reading s wa s use d fo rth e frequenc ycoun t an d short-ter m averagin g dat a reductio n metho d evaluations . 

### 29P.3 6

o r stac k opacit ymonito r i s presen t t o provid e a n instrumenta l measuremen t t o serv e a s th e referenc e opacit yvalue) . Consequently , th e onl ymeasur e tha t coul d b e use d t o asses s observe r erro r i s between-observe r precision . Simul
taneou s opacit yreading s b ytw o observer s wer e use d a s th e basi s o f th e between
observe r precisio n calculations . Som e o f th e fugitiv e emission s dat a use d wer e obtaine d from basi c oxyge n furnac e (BOF ) roo f monitor s and nonmetalli c minera l processin g facilitie s and wer e gathere d i n suppor t o f developmen t o f NSPS . Th e remainde r o f th e fugitiv e emission s dat a use d wer e collecte d b yEP Aregiona l personne l fro m variou s iro n an d stee l source s i n severa l EP Aregion s a s par t o f a V E emission s dat a ban k fo r evaluatio n o f reasonabl yavailabl e contro l technolog y(RACT) . Fo r al l o f th e regiona l fugitiv e emission s data , on e o f th e tw o paire d observer s wa s a nonagenc yperso n eithe r associate d wit hth e sourc e o r contracte d b yth e source . I n total , 31 0 hour s o f observation s (eac hobserver ) wer e evaluated . Eac h run wa s typicall yeithe r fo r a 30-minut e o r 60-minut e observatio n period . Onc e th e initia l dat a se t wa s obtaine d and reviewed , i t becam e apparen t tha t a t som e o f th e source s a disproportionat e amoun t o f th e reading s wer e zer o opacity . Sinc e evaluatio n o f observe r precisio n base d o n observation s a t th e 0-5 % opacit y leve l woul d no t provid e a usefu l indicatio n o f metho d accuracy , a subse t o f th e tota l dat a se t wa s established . Th e dat a subse t mad e up approximatel y80 % o f th e origina l dat a se t (24 0 hour s pe r observer)! .
1 Approximatel y30 % o f th e dat a set s ha d opacitie s nea r o r abov e th e 20 % opacit ylevel .


### 3 0P.3 7 r-rr r| •-;<•• - •

Between-observe rprecisio n fo rth e aggregate-tim e metho d wa' s calculate d fo rth e fugitiv e dat a set . Sinc e n o transmissomete rwa s availabl e t o whic h th e observers ' dat a coul d b e compared , a n actua l composit e erro restimat e (observe r bias , within-observe rprecision , an d between-observe rbias ) canno tb e determined . However , th e between-observe rprecisio n ter m ca n b e determine d and compare d t p th e between-observe rprecisio n ter m calculate d fo rth e RT P dat a tha t wa

s utilize d i n calculatin g a composit e erro restimate . A s illustrate d i n Tabl e 5 , th e mean between-observe rprecisio n fo rth e fugitiv e emission s wa s 166 seconds , wit h a > rang e o f104-239 , whe n determinin g th e aggregat e tim e ove ra rang e o f1 0 t o 25 % opacity . Th e mea

n between-observe rerro ro f166 second s wit h th e fugitiv e emp's sio n dat a se t compare s t o th e between-observe rerro ro f15 9 second s determine d durin g th e RT

P smok e generato rstud y(whit e intermitten t plumes) . Thi s i s a h indicatio n tha t th e observer s performe d abou t a s wel l i n th e fiel d observin g th e fugitiv e emission s as the ydi d observin g th e smok e generato remissions . Between-observe rprecisio n wa s als o examine d whe n opacit yaveragin g method s o fdat a analysi s wer e employed . Tabl e 6 show s tha tth e standar d deviatio n (esti mat e o fbetween-observe rprecision ) i s 2.1 % opacit yfo ra six-minut e averagin g perio d an d 2.4 % fo ra three-minut e averagin g period . I n bot h cases , th e dif- ! ferenc e betwee n observer s i s a ta leve l tha t ca n b e considere d acceptable ; furthermore , onl ya smal l increas e in . between-observe rprecisio n i s note d whe n a shorte raveragin g tim e i s used .



### 3 1P.3 8 ""•'* • * • . «

TABL E 5 . BETWEEN-OBSERVE R PRECISIO NFOR FUGITIV E EMISSION S DAT A

(AGGREGATE-TIM E METHOD )
Variabl e O T 15 2 O T 2 0 O T 2 5 O T 3 0 Mea n Valu e Mea n

\ Aggregat e (seconds ) 

### 52 0 29 6 18 3 12 9 Tim e SD 1

(seconds ) 

### 23 9 19 0 13 0 10 4 16 6



### 1 Between-observe r erro r term . O T 1 5 = observe d tim e >15 % opacity , O T 2 0 = observe d tim e >20 % opacity , etc .


### 3 2P.3 9 r ry e -I ]

TABL E 6 . BETWEEN-OBSERVE R PRECISIO NFOR FUGITIV E EMISSION S DAT A

(OPACIT Y AVERAGIN GMETHOD )

Variabl e SD 1

( % opacity ) Observe r differenc e _<7.5 % opacit y (percen t o f runs ) Three-Minut e Averag e 2. 4 

### 9 2 Six-Minut e Averag e 

### 2. 1 9 3



### 1 Between-observe rerro rterm .

3 3P.4 0

5. 4 Definitio n o fIntermitten t Emission s

Wheneve ran yne

wregulatio n o rmeasuremen t metho d i s proposed , a ke y requiremen t i s tha t th e source s affecte d b e clearl yan d unambiguousl ydefined . Anydefinitio n o fintermitten temission s wil l hav e t o tak e th e followin g int o account :

. Mus t b e clea ra s t o whic h emissio n source s th e metho d applies .

. Must includ e as man ysignifican tsource s o femission s a s possibl e whic h ar e no tadequatel ycovere d bysix-minut e averages .

. Shoul d b e eas yt o understan d an d us e i n th e field . Severa l possibl e definition s wer e examined . The yinclud e definin g bysourc e typ e (i.e. , cok e ove n pushes) ; definin g bytim e abov e th e standar d (les s tha n si x consecutiv e minute s abov e th e standard) ; definin g bytim e whe n emission s ar e greate rtha n zer o (les s tha n si xconsecutiv e minute s o fvisibl e emissions) ; an d definin g byth e statistica l variabilit yo rth e rat e o fris e an d fal l o fth e plume . Th e simples t definitio n tha t applie s t o th e greates tnumbe ro fsource s o f significan t emission s i s th e following :

"Intermitten t emission s ar e thos e emission s tha t excee d th e appli cabl e opacit ystandar d fo rles s tha n si xconsecutiv e minutes. " Determinin g applicabilit ybysourc e typ e coul d als o b e use d i n some circum stance s wher e th e sourc e typ e i s fairV yconsisten ti n producin g intermitten t plumes . Fo rexample , th e amende d NSP S emissio n standar d propose d fo rsecondar y emission s fro m basi coxyge n furnaces , whic h hav e bee n designate d as intermitten t emissio n sources , i s determine d usin g a three-minut e average. 1



### I Propose d Januar y20 , 1983 . 

## 3 4P.4 1

Definin g intermitten t emission s a s thos e emission s tha t ar e greate r tha n 0 % opacit yfo r les s tha n -si xconsecutiv e minute s woul d hav e th e drawbac k o f onl y i coverin g som e intermitten t sources ; i t is , therefore , no t desirabl e a s a mor e genera l definition . i Definin g intermitten t emission s b yth e rat e o f plum e opacit ychang e wa s considered . On e possibl e definitio n woul d b e t o calculat e th e standar d 'deviatio n o f th e opacitie s —i f th e standar d deviatio n exceede d 12% , the n th e plum e woul d b e considere d intermittent . Amajo r drawbac k wit hthi s typ e o f definition ! i s tha t determinatio n o f a violatio n woul d b e difficul t t o mak e i n th e field . Manyaaencie s conside r i t highl ydesirabl e fo r th e inspecto r t o b e abl e to : hav e
, I I immediat e discussion s wit hresponsibl e sourc e official s whe n a violatio n occurs . Knowin g whethe r o r no t a violatio n ha s actuall yoccurre d i s an importan t piec e o f informatio n fo r th e inspecto r i n suc hcircumstances . Therefore , i t was ! determine d tha t usin g th e rat e o f plum e opacit ychang e t o defin e intermitten t emission s i s no t practical . 5. 5 Recommende d Readin g Method s - Intermitten t Emission s '

Th e frequenc ycoun t metho d shoul d b e use d fo r intermitten t emissio n source s whe n tim e exemption-typ e regulation s apply . .Th e rational e fo r thi s i s discusse d i n mor e detai l i n Sectio n 5.6 , bu t th e majo r reason s includ e compatibilit y i o f th e readin g metho d wit hth e standard , a reasonabl e accurac ylevel , an d pas t experienc e showin g tha t th e frequenc ycoun t metho d i s a n effectiv e too l i n evaluatin g intermitten t emission s sources . Th e stopwatc hmetho d ca n b e use d fo r intermitten t sources , and , i n fact , i s ofte n specifie d an d effectiv e whe n dealin g wit hextremel yshort-tor memissio n source s suc ha s cok e ovens . Severa l agencie s us e th e stopwatc hmethod , parti
cularl yi n conjunctio n wit hcok e ovens . A s wit hanymethod , th e stopwatchimetho d 

### 3 5P.4 2

ca n b e used i fi t i s consisten twit h th e applicabl e emissio n standar d an d i fa suitabl e erro rmargi n i s considered . I ti s no tinclude d as a preferre d metho d fo rth e followin g reasons :

. Th e stopwatc h metho d i s no t i n widesprea d us e and require s some trainin g i n additio n t o Metho d 9 trainin g an d certification .

. I t i s desirabl e t o hav e as fe wopacit yreadin g method s as possibl e i n a give n State . Th e tw o preferre d method s fo rintermitten t emissio n source s (frequenc ycoun t an d three-minut e average ) wer e chose n i n par t becaus e the ywer e eithe rth e same o ra mino rmodificatio n o f th e existin g metho d fo rothe rsourc e types . Th e stopwatc h method , however , i s normall yuse d onl yfo rhighl yintermitten tsources , and i t i s substantiall ydifferen t fro m othe rreadin g methods .

. Th e stopwatc h metho d doe s no teasil ylen d itsel ft o factorin g i n a n erro rbuffe rfo ropacity . Three-minut e averagin g shoul d b e use d fo rintermitten t emissio n source s subjec t t o averag e opacity-typ e regulations . One-an d two-minut e averagin g coul d be used , bu t d o hav e slightl yhighe rerro rmargin s (se e Table s 7 an d 8 ) associate d wit h the m tha n three-minut e averaging . Th e three-minut e averag e wa s chose n ove r th e shorte rtime s becaus e i t ha s a greate raccurac ywhil e stil l bein g a shor t enoug h averagin g tim e t o evaluat e mos t intermitten temissio n source s effectively . An yo fthes e method s ca n be used . However , th e reading/dat a reductio n metho d mus t b e specifie d an d mus t b e compatibl e wit h th e applicabl e emissio n regulation , and th e accurac yo fth e metho d shoul d b e considere d befor e makin g a determinatio n o fcompliance . 5. 6 Recommende

d Readin g Method s - Tim e Exemptio n Regulation s Th e frequenc ycoun tmetho d o freadin g an d dat a reductio n wa s recom mende d fo rus e wit h tim e exemption-typ e regulation s fo rth e followin g reasons :

. Frequencycoun t i s ver ycompatibl e wit h tim e exemption s an d i s consisten t wit h wha t i s commonl yunderstoo d whe n on e say s " xminutes " --tha t is , th e su m tota l o fxminute s rathe rtha n a n averag e o fxminutes . 3 6P.4 3



### TABLE - 7 . ERRORSTANDARDDEVIATION S B YSMOK E COLO

R FO RDIFFEREN T AVERAGIN

GTIMES l Averagin gTime , Minute s Smok e Blac k 8.3 0 7.8 7 7.7 3 7.4 8 Co l o r

Whit e 7.8 3 7.0 0 6.8 0 6.4 8 

### 1 2 3 6



# r Researc hTriangl e Institute , Researc hTriangl e Park , NC , Lette r Repor t date dSeptembe r 8 , 1983 . 

## 3 7P.4 4 n ww>"-y



### TABL E 8 . DIFFERENC E BETWEEN OBSERVER S FO

RFUGITIVE EMISSION S DATA l FORDIFFEREN T AVERAGINGTIMES 2 Averagin g Time , Minute s 1 2 3 6 Varianc e 8.4 0 6.7 1 5.7 3 4.4 8 Standar d Deviation 3 2.9 0 2.5 9 2.3 9 2.1 3



# r Ther e ar e no transmissomete r reading s for th e fugitive emission s data ; onl y difference s betwee nobserver s canbe determined . Researc hTriangl e Institute , Researc hTriangl e Park , NC , Lette r Repor t date dSeptembe r 8 , 1983 . StandardDeviatio n= Variance . 

## 3 8P.4 5

. Frequenc ycoun t ha s bee n use d wit htim e exemptio n regulation s fo r at leas t 3 5 years .

. Frequenc ycoun t ha s sufficien t accurac yand ha s prove d a n effectiv e too l i n evaluatin g opacity .

. Frequenc ycoun t work s wel l wit hintermitten t a s wel l a s mor e continuou s emissions . ' Six-minut e averagin g a s specifie d i n Metho d 9 ca n b e use d withou t modifi
catio n onl ywit hsix-minut e tim e exemptions , and onl ywher e Metho d 9 i s include d i n th e regulation s a s th e require d readin g method . Othe r tim e exemptio n period s coul d b e averaged , bu t woul d requir e detaile d and specifie d dat a reductio n methods . Th e accurac yo f eac haveragin g tim e woul d hav e t o b e considere d fo r complianc e evaluatio n purposes ; tha t is , i f th e readin g metho d allowe d a three-minut e ^verag e fo r th e tim e exemptio n perio d and a six-minut e averag e fo r compariso n wit hth e bas e opacit ystandard , the n th e accurac yo f three-minut e averagin g woul d hav e t. c b e considere d fo r th e three-minut e average , and th e accurac yo f th e six-minut e nverag e include d fo r th e six-minut e average . Acombinatio n o f frequenc ycoun t fo r th e tim e exemptio n perio d and six
minut e averagin g fo r th e bas e standar d ca n b e used , bu t wil l b e considerabl y les s stringen t tha n th e straigh t frequenc ycoun t metho d and i s no t recommende d I fo r tha t reason . Whe n usin g th e frequenc ycoun t method , onl yth e tim e exemptio n perio d i s o f concern . Fo r example , a typica l tim e exemptio n regulatio n wil l prohibi t emission s equa l t o o r greate r tha n 20 % opacit yexcep t fo r thre e minute s pe r hour . Onc e th e tim e exemptio n perio d ha s bee n exceede d (wit hth e erro r margi n figure d in) , the n th e sourc e i s i n violatio n eve n i f al l th e othe r opacit yreading s ar e "0" . I f six-minut e averagin g i s attempte d wit ha tim e exemptio n regulation , however , th e sam e tim e exemptio n perio d (wit herror ) woul d b e require d plu s th e remainin g reading s average d togethe r woul d hav e 3 9P.4 6

t o excee d 20

% plu s th e erro rmargi n fo rth e six-minut e average . An yo fth e reading/dat a reductio n method s discusse d i n thi s guidelin e documen t ca n b e use d unde rappropriat e circumstance s subjec t t o th e followin g stipulations :

. Th e dat a reductio n metho d mus tbe specifi can d unambiguous .

. Th e dat a reductio n metho d mus t be consisten twit h th e opacit ystandard .

. Th e accurac yo fth e reading/dat a reductio n metho d mus t be take n int o accoun tbefor e complianc e wit h th e opacit ystandar d ca n b e determined .

. Th e relativ e stringenc yo fth e differen treading/dat a reductio n method s (includin g accurac yo fmethod ) shoul d be considere d befor e choosin g a reading/dat a reductio n method . 5. 7 Accurac yo fth e Frequenc yCoun tMetho d - Al l Plum e Type s

Th e frequenc ycoun t metho d o fopacit yreadin g an d dat a reductio n con tinue s t o b e widel yuse d byStat e an d loca l ai rpollutio n contro l agencies . Althoug h thi s metho d ha s bee n used fo rmore tha n 30 years , n o previou s stud y t o asses s th e accurac yo fth e metho d wa s identifie d prio rt o thi s report . Rather , agencie s have estimate d th e accurac yo fth e metho d base d o n thei rextensiv e ex perienc e wit h it , includin g smok e schoo l results . Th e intermitten temissio n fiel d study l describe d earlie revaluate d th e frequenc ycoun tmetho d o n highl yintermitten tplumes . Tw o othe rbrie ffiel d test s wer e als o carrie d out , on e wit h slowl ychangin g plume s and on e wit h continuou s plumes . Abatter yo fslowl ychangin g plume s wa s shown t o a pane l o fobserver s i n Jacksonville , Florid a o n Januar y17 , 1981 . Te n observer s o fvaryin g experienc e level s rea d a tota l o f18 0 twelve-minut e run s fro m a smok e generato rmeetin g 7 . Conducte d i n Researc h Triangl e Park , NC , Ma y19-23 , 1980 . 40rj- |-,-.,-,T „

Metho d 9 specifications . Si xminute s o fslowl ychangin g opacit ywer e "hidden " withi n eac h 12-minut e period , and onl ythes e six-minut e dat a set s wer e used . Th e opacit ylevel s wer e varie d steadil yove rth e si xminute s i n on e o fthre e patterns : 20

% change , 40

% change , an d 60

% change . Astri p char t showin g plum e opacit yfo ron e o fth e run s i s shown i n Figur e 5 a s a n example . Reade rposi tionin g an d dat a recordin g wer e as pe rMetho d 9 . Al l reader s wer e certifie d th e wee k

befor e th e fiel d tria l accordin g t o Metho d 9 requirements . Asimila rshort-ter m fiel d tes to n continuou s plume s wa s hel d i n Orlando , Florid a o n Octobe r18 , 1980 . Twent yobserver s rea d a tota l o f36 0 twelve-minut e sets . Si xminute s o funchange d opacit yals o wer e "hidden " withi n eac h 12-minut e period , wit h th e si xminute s o fcontinuou s emission s constitutin g th e dat a set s used . Again , th e smok e generato rme t Metho d 9 criteria . Th e observer s had al l bee n certifie d as pe rMetho d 9 specification s th e wee k befor e th e study . Reade r positionin g and dat a recordin g wer e als o accordin g t o Metho d 9 . I n additio n t o thes e thre e studies , dat a fro m th e EP A"Riverbend " stud yo f 197 4 wer e evaluated . Th e Riverben d dat a wer e gathere d as par to fth e Metho d 9 repromulgation . Thes e fou rstudie s o fvaryin g plum e configuration s wer e used t o evaluatj e th e accurac yo fth e frequenc ycoun t metho d o fopacit yobservatio n an d dat a reduction . Som

e descriptiv e dat a on-thes e fou rstudie s ar e liste d i n Tabl e 9 . Frequenc yCoun t Erro rMargi n j Th e frequenc ycoun t metho d erro rcoul d b e describe d thre e ways : 1 ) opatit y erro rfo reac h 15-secon d readin g (i.e. , allo w10 % opacit yerro rfo reac h reading) ; 2 ) tim e erro rfo reac h six-minut e dat a se t (i.e. , allo won e minut e extr a o f[exces s emissions) ; o r3 ) a combinatio n o fopacit yan d tim e errors . 

### 4 1P.4 8

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### 4 2P.4 9 I '

TABL E 9 . DATASET S USE D T O EVALUAT E FREQUENC Y COUN T METHO D ACCURAC Y
1 Name/Locatio n 1 o fStud y Riverben d Stud y 1 RT P Stud y 1 (Researc h Triangl e 1 Florid a I Stud y 1 (Orlando , Florida ) P a

1 Florid a I I Stud y 1 (Jacksonville , Flori d He ,

a ) NC )

TOTA L Descriptio n Coal-fire d powe rplan t Highl yintermitten t emission s - smok

e generato r Continuou s plume s - smok e generato r Slowl ychangin g plume s - smok

e generato r Numbe ro f Dat a Sets l 168 1,17 2 36 0 18 0 1,88 0 Yea ro fStudy !

197 4 1 198 0 | 198 0 I i . 198 1 | [



# r Six-minut e dat a sets . 4 3P.5 0

Ther e ar e tw o concern s wit hth e accurac yo f anyopacit ytes t method : 1 ) tha t th e opacit yreadin g sho wa violatio n when , i n fact , ther e i s one ; and 2 ) tha t th e readin g no t sho wa violatio n whe n ther e i s n o violation . In othe r words , th e tes t metho d (wit herro r margin ) shoul d sho wa s man y"true " violation s whil e showin g a s fe w"false " violation s a s possible . Th e combinatio n o f opacit yand tim e buffer s fo r th e frequenc ycoun t metho d wa s chose n fo r tw o reasons : 1 ) it s current , us e b ycontro l agencies , an d 2 ) a compariso n o f it s relativ e stringenc yi n th e dat a se t evaluate d (se e Chapte r 6.0) . Tw o o f th e leadin g ai r pollutio n contro l agencie s wit hvigorou s enforce
men t program s us e th e frequenc ycoun t metho d wit hth e opacity/tim e buffe r combination , indicatin g tha t i t is , i n thei r experience , th e mos t practica l an d stringen t erro r margin . Also , a compariso n (se e Chapte r 6.0 ) o f th e numbe r o f violation s foun d usin g th e differen t type s o f erro r margin s i n a sampl e dat a se t showe d th e combinatio n o f opacit yand tim e buffer s t o b e th e mos t stringent . Th e actua l amount s o f th e tim e and opacit yerror s wer e calculate d fo r th e fou r dat a set s used . Tabl e 1 0 show s th e accurac ylevels , expresse d b y percentiles . Whe n th e give n opacit yand tim e buffer s wer e use d wit hth e fou r dat a sets , th e associate d percentil e indicate s th e percentag e o f dat a set s wher e ther e wa s n o positiv e bia s (th e observe r tim e wit hbuffer s abov e th e standar d wa s les s tha n th e transmissomete r tim e abov e th e standard) .



### 4 4P.5 1 ' • • r ' 'vi'' -

TABL E 10 . ACCURAC Y LEVEL S FOR FREQUENC Y COUN T METHOD 1
99 % o f dat a sets :

Blac k Smoke : 0. 4 minute/ 6 minutes , 10 % opacit yeac h15-secon d readin g Whit e Smoke : 1. 0 minute/ 6 minutes , 10 % opacit yeac h15-secon d readin g 95 % o f dat a sets :

Blac k Smoke : Whit e Smoke : 85 % o f dat a sets :

Blac k Smoke : Whit e Smoke : 0. 1 minute/ 6 minutes , 10 % opacit yeac h15-secon d readin g

0. 2 minute/ 6 minutes , 10 % opacit yeac h15-secon d readin g
0.0 4 minute/ 6 minutes , 5 % opacit yeac h15-secon d readin g 0. 2 minute/ 6 minutes , 5 % opacit yeac h15-secon d readin g

1,88 0 six-minut e set s o f dat a fro mthes e studies : Park , Florid a I , and Florid a II . Riverbend , Researc hTrilangl e 

### 4 5P.5 2

6. 0 RELATIV E STRINGENC YO F READING/DAT

AREDUCTIO

N METHOD

S Eac h opacit yreadin g an d dat a reductio n metho d wil l hav e some leve l o faccurac yassociate d wit h i ttha t shoul d b e considere d befor e decidin g tha t a violatio n ha s occurred . Agencie s tha t chang e thei rstandard s o rreadin g methods , o restablis h ne

wstandard s o rreadin g method s i n regulations , permits , o r consen t decrees , ar e concerne d abou tth e relativ e stringenc yo fthei rchoices . Fo ra give n sourc e category , fo rexample , wil l ther e b e more violation s foun d i f a three-minut e tim e exemptio n standar d plu s stopwatc h readin g metho d i s used , o ri fn o tim e exemptio n an d a three-minut e averag e i s used ? Ametho d fo rcomparin g differen topacit ystan d ard/rea d in g metho d combina tion s wa

s develope d an d use d i n evaluatin g intermitten tfugitiv e emission s fro m iro n an d stee l an d fro m nonmetalli cminera l processin g facilities. ! Sectio n 6. 1 list s th e step s i n performin g a relativ e stringenc yanalysis . Basically , th e analysi s involve s evaluatin g differen t actua l opacit yreading s and determinin g ho wman y violation s occu rwit h th e differen tmethod/standar d combinations ; th e combinatio n wit h th e mos t violation s i s th e mos t stringent . Fo rthi s analysis , w e compare d th e followin g thre e method/standar d combinations : Canno t excee d 20

% opacity , six-minut e average .

. Canno t excee d 20

% opacity , three-minut e average .

. Canno t equa l o rexcee d 20 % opacit yexcep t fo rthre e minutes/hour , frequenc ycoun tmethod . Th e specifi cassumption s and erro rmargin s fo rthes e combination s appea ri n 

### Sectio n6.2 .
I : Thi s dat a wa

s th e same as tha t use d fo rth e between-observe rprecisio n evaluatio n discusse d i n Sectio n 5.3 , an d i t i s more full ydescribe d there . 

### 4 6Durin g th e analysis , th e opacit yreading s wer e "tested " firs t b yassumin g n o margi n o f erro r fo r th e readin g method , an d the n b yassumin g th e appropriat e margi n o f error . Th e result s sho wtha t th e tim e exemption-typ e regulation ' wit h th e frequenc ycoun t metho d wa s mor e stringen t wit hn o erro r margi n tha n th e three
minut e average , bu t almos t identica l i n stringenc ywhe n th e erro r margi n Wa s figure d in . A s expected , th e six-minut e averag e wa s no t a s stringen t o n thes e intermitten t emissions . Asummar yo f th e analysi s appear s i n Tabl e 11 . Th e ra wdat a use d fo r thi s analysi s ar e considere d typica l fo r intermitten t emissio n sources . Th e nearl yidentica l stringenc yo f th e tw o recommende d methods , i th e frequenc ycoun t an d three-minut e average , indicate s tha t eithe r ca n be ' use d o n intermitten t emissio n sources , provide d th e readin g metho d i s consisten t wit h th e opacit ystandard . Differen t emissio n source s wit hplume s o f differen t vari
abilit yma ysho won e metho d t o b e significantl ymor e stringen t tha n th e other . Stringenc yanalyse s ca n b e performe d followin g th e guideline s i n Sectio n 6. 2 fo r specifi c sourc e categorie s t o determin e mor e precisel yth e mos t stringen t opacit y standard/readin g metho d combination . 6. 1 Procedur e fo r Evaluatin g th e Relativ e Stringenc yo f Opacit yStandard/Readin g Metho d Combination s J

. Obtai n a statisticall ysufficien t bodyo f opacit yreading s a t o r abov e th e opacit ystandar d fro m differen t facilities .

. Brea k th e opacit ydat a int o 60-minut e dat a sets . Assum e a leve l o f accuracy't o b e use d i n comparin g th e method s (say , 85 % accurac ylevel) .

. Determin e on e combinatio n o f opacit ystandard/readin g metho d (say , n o mor e tha n 20 % opacit yexcep t 3 minutes/hour , usin g th e frequenc y coun t method ) t o b e tested .

. Tes t th e opacit ystandard/readin g method , takin g int o accoun t th e |1 eve ! o f accurac yo f th e method . Determin e th e numbe r o f 60-minut e datia sets . i n violatio n o f th e standard . 

### 4 7TABLE 1 1 Relativ e Stringenc yAnalysi s o fIntermitten t Fugitiv e Emissio n Data ! j Opacit yReadin g I Metho d I Frequenc yCoun t Method 1 Violatio n wit h n o 1 erro rmargi n j Violatio n wit h I erro rmargi n I Three-Minut e Averag e 1 Violatio n wit h n o I erro rmargi n I Violatio n wit h 1 erro rmargi n 1 Six-Minut e Averag e 1 Violatio n wit h n o j erro rmargi n I Violatio n wit h 1 7.5 % opacit yerro r Nonmetalli c Source s (2 1 # Set s
2 1 3
6 2
5 2 Minera l

Sets ) %Set s
100 1 4
2 9 1 0
2 4 1 0 Iro n &Stee l Source s

(13 7 Sets ) # Set s % Set s
133 6 9
11 3 6 9
8 4 55 97

50
82 50
6 1 4 0 Al l Source s - - Readin g <30 Minute s T8 9 Sets ) # Set s % Set s
8 6 3 1
5 6 2 6
36 1 5 97

3 5
63 2 9
40 1 7 Al l Source s 60-Minut e Readings(6 9 Sets ) # Set s % Set s
6 8 4 1
6 3 45
5 3 42 9 9

5 9
9 1 65
77 6 1 TOTA

LAl l Al l Rea d i n (15 8 Sets ) # Set s %
154 7 2
11 9 7 1
8 9 5 7 Sources | gs 1 Set s j
9 7 | 4 6 |

7 5 | 45 |
5 6 | 3 6 | 

### 1 51 6 dat a set s total , wit h tw o reading s (tw o observers ) fo reac h o fth e 51 6 dat a sets . Th e firs t readin g o feac h pai rwas chose n fo revaluation . Onl ythos e reading s showin g a violatio n b yan yo fth e thre e method/standar d combination s wer e include d i n th e 158 sets . 4 8. Repea tth e tw o previou s step s wit h othe rcombination s o fopacit y stan d ar d /rea d in g method s unde rconsideration .

. Th e opacit ystan d ard/rea d in g metho d showin g th e mos t violation s is . th e mos t stringent . 6. 2 Assumption s Use d fo rRelativ e Stringenc yEvaluatio n Regulations/readin g metho d compared :

. Shal l no t equa l o rexcee d 20 % opacit yexcep tfo rthre e minutes/hou r ( frequenc ycoun t method) . Shal l no texcee d 20

% opacit y(3-minut e an d 6-minut e averagin g methods) . Confidenc e interva l chose n fo rerro rmargins : a95% . Erro rmargin s used :

. 10 % opacit y+ 1 5 seconds/ 6 minutes : frequenc ycoun tmethod .

. 11.8 % opacity : 3-minut e average . 7.5 % opacity : 6-minut e average . Frequenc ycoun t dat a reduction :

. Fo r1-hou rreadings : 1 4 reading s a t>30 % opacit y( 1 extr a readin g fo r eac h additiona l 6-minut e perio d wher e 15-secon d reading s ar e use d fo r tim e exemption) .

. Fo r30-minut e readings : 8 reading s a t ^30 % opacit y( 1 extr a readin g fo reac h additiona l 6-minut e perio d wher e 15-secon d reading s ar e used , fo rtim e exemption)! . i

. Fo rn o erro rmargin : 1 3 reading s >20 % opacit yfo r1-hou rreading ; 7 reading s >20

% opacit yfo r30-minut e readings . Onl yfirs t readin g o feac h pai rwas evaluated . Onl yreading s wher e on e o rmore method s showed violation s wer e include d i n th e dat a se t(15 8 reading s ou to f51 6 reviewed) .


## 1 Fo r30-minut e readings , a 1-1/2-minut e tim e exemptio n perio d wa s assumed rathe rtha n th e 3 minute s pe rhour . 4 9P.5 6

7. 0 SUMMAR

YAN D MAJO R CONCLUSION

S Opacit yobservation s take n b ycertifie d reader s followin g prope rreadin g procedure s continu e t o b e th e mos teffectiv e metho d o fevaluatin g visibl e emissions . Base d o n th e evaluatio n o fthre e principa l opacit yreadin g method s an d dat a fro m fou rfiel d studies , th e majo rconclusion s ar e a s follows :

. Fo rintermitten t emissio n sources , th e recommended readin g method s are : 1 ) frequenc ycoun tfo rus e wit h tim e exemption-typ e regulations , an d 2 ) three-minut e averagin g fo rus e wit h averagin g opacity-typ e regulations .

. Th e stopwatc h metho d i s i n curren t use , particularl ywit h highl yintermitten t plumes . I t ca n b e used effectively , provide d a n appropriat e erro rmargi n i s included .

. Ausabl e definitio n o fintermitten t emission s i s "emission s i n exces s o fth e opacit ystandar d fo rles s tha n si xconsecutiv e minutes" .

. Th e frequenc ycoun t metho d shoul d b e use d wit h mos ttim e exemption-typ e regulations . Six-minut e averagin g shoul d onl yb e use d whe n th e tim e ex emptio n perio d i s si xminute s an d six-minut e averagin g i s specifie d i n th e promulgate d readin g method . Othe raveragin g method s ar e no t recommended fo rus e wit h tim e exemption-typ e regulations , bu t coul d b e use d i fspeci fie d i n th e promulgate d readin g method .

. Th e leve l o faccurac yi s establishe d an d include d i n thi s documen t fo rth e frequenc ycoun tmetho d (al l plum e types) ; one- , two - an d three-minut e aver agin g (intermitten t plumes) ; an d th e stopwatc h metho d (intermitten t plumes) .

. Th e relativ e stringency-o fdifferen t opacit ystandard/readin g metho d combi nation s i s a n importan t consideratio n whe n ne wregulation s ar e adopted , ol d regulation s ar e changed , o rpermit s o rconsen t decree s ar e negotiated . Aprocedur e fo rcomparin g th e relativ e stringencie s fo rspecifi csourc e categorie s o rindividua l facilitie s i s presente d i n thi s document .

. Th e three-minut e averag e an d frequenc ycoun t method s wer e foun d t o b e almos t identica l i n stringenc ywhe n a typica l dat a se to fintermitten temission s wa s analyzed .

5 0P.5 7



### APPENDI XA Federa l Register , Vol . 39 , No . 219 , Referenc e Metho d 9P.5 8



### Titl e 40
—Protectio no f th e Environmen t CHAPTE R1—ENVIRONMENTA L PROTECTIO NAGENC Y Subchapte r C--Ai r Program s (FR L 391-6 ) PAR T 60—STANDARD S O F PERFORMANC E FORNE WSTATIONAR YSOURCE S

Opacit yProvision s "OnJun e 29 , 1973 , th e Unite dState s Cour t o f Appeal s fo r th e Distric t o f Columbi a i n'PortlandCemen t Associatio nv . Ruckelshaus, ' 48 6 F.2 d37 5 (1973 ) remande dt o EP Ath e standar do f performanc e fo r Portlan dcemen t plant s (4 0 CF R 60.6 0 e t seq. ) promulgate db yEP Aunde r sectio n11 1 o f th e Clea nAi r Act . In th e remand , th e Cour t directe dEP At o reconside r amon g othe r thing s th e us e o f th e opacit ystandards . EPAha s prepare da respons e t o th e remand . Copie s o f thi s respons e ar e availabl e fro mth e Emissio nStandard s andEngineerin g Division , Environmenta l Protectio nAgency , Researc hTriangl e Park , N . C . 27711 , Attn : Mr . Do nR . Goodwin . Indevelopin g th e response , EP Acollecte dandevaluate da sub
stantia l amoun t o f informatio nwhic hi s summarize dandreference di nth e response . Copie s o f thi s informatio nar e availabl e fo r inspectio ndurin g norma l offic e hour s a t EPA' s Offic e o f Publi c Affairs , 40 1 MStree t SW. , Washington , D . C . EP Ade
termine dtha t th e Portlan dcemen t plan t standard s generall ydi dno t requir e re visio nbu t di d(not , sic ) findtha t certai nrevision s ar e appropriat e t o th e opa cit yprovision s o f th o standards . Th e provision s promulgate dherei ninclud e .* i revisio nof

§60.11 , Complianc e wit hStandard s andMaine-- " "' ; -, : 

### . • ••>..-.t'- s , .- • revisio nt o th e opacit ystandar dfo r Portlan dcemen t plants , andrevision s t o Referenc e Metho d9 . Th e base s fo r th e revision s are discusse di ndetai l i nth e Agency' s respons e t o th e remand . The yar e summarize dbelow . Th e revision s t o §60.1 1 includ e th e modificatio no f paragrap h(b ) an dth e additio no f paragrap h(e) . Paragrap h(b ) ha s bee nrevise dt o indicat e tha t whil e Referenc e Metho d9 remain s th e primar yan daccepte dmean s fo r determinin g complianc e wit hopacit ystandard s i nthi s part , EP Awil l accept'a s probativ e evidenc e i n certai nsituation s an dunde r certai ncondition s th e result s o f continuou s monitorin g b ytransmissomete r t o determin e whethe r a violatio nha s i nfac t occurred . Th e revisio nmake s clea r tha t eve ni nsuc hsituation s th e result s o f opacit yreading s b yMetho d9 remai npresumptivel yvali dandcorrect . Th e provision s i nparagrap h(e ) provid e a mechanis m fo r anowne r o r operato r t o petitio nth e Administrato r t o establis ha nopacit ystandar dfo r a naffecte d facilit ywher e suc hfacilit ymeet s al l applicabl e standard s fo r whic ha performanc e tes t i s conducte dunde r §60. 8 bu t fail s t o mee t anapplicabl e opacit ystandard . Thi s provisio ni s intende dprimaril yt o appl yt o case s wher e a sourc e install s a ver v larg e diamete r stac k whic hcause s th e opacit yo f th e emission s t o b e greate r tha n i f a stac k o f th e diamete r ordinaril yuse di nth e industr ywer e installed . Althoug hthi s situatio ni s considere dt o b e ver yunlikel yt o occur , thi s provisio n wil l accommodat e suc ha situation . Th e provisio ncoul dals o appl yt o othe r situation s wher e fo r anyreaso nanaffecte dfacilit ycoul dfai l t o mee t opacit y A- lP.5 9

standard s whil e meetin gmas s emissio nstandards , althoug hn o suc hsituation s ar e expecte dt o occur . A revisio nt o th e opacit y standar dfo r Portlan dcemen t plant s i s promulgate d herein . Th e revisio nchange s th e opacit y limi t fo r kiln s fro m 1 0 percen t t o 2 0 percent . Thi s revisio ni s base do nEPA' s polic y o nopacit y

standard s an dth e ne w emissio ndat a fro m

Portlan dcemen t plant s evaluate dby EP A durin git s reconsidera tion . Th e preambl e t o th e standard s o f performanc e whic hwer e promulgate do n Marc h8 , 197 4 (3 9 FR9308 ) set s fort hEPA' s polic y o nopacit y

standards : (1 ) Opacit y limit s are

independen t enforceabl e standards ; (2 ) wher e opacit y an d mass/concentratio nstandard s ar e applicabl e t o th e sam e source , th e mass/concen tratio nstandard s ar e establishe da t a leve l whic hwil l resul t i nth e design , in stallation , an doperatio no f th e bes t adequatel y demonstrate dsyste m o f emissio n reductio n(takin gcost s int o account) ; an d(3 ) th e opacit y standard s ar e estab lishe da t a leve l whic hwil l requir e prope r operatio nan dmaintenanc e o f suc h contro l systems . Th e ne w dat a indicat e tha t increasin gth e opacit y limits ! fo r kiln s fro m

1 0 percen t t o 2 0 percen t i s justified , becaus e suc ha standar dwil l stil l requir e th e design , installation , an doperatio no f th e bes t adequatel y demonstrate dsyste m o f emissio nreductio n(takin gcost s int o account ) whil e eliminatin go r minimizin gth e situation s wher e i t wil l b e necessar y t o promulgat e a ne w opacit y

standar dunde r §60.11(e) . Inevaluatin gth e accurac y o f result s fro m

qualifie dobserver s followin gth e procedure s o f Referenc e Metho d9 , EP A determine dtha t (som e revision s t o Referenc e Metho d9 are

consistentl y

abl e t o evaluatio nshowe dthat , sic ) observer s traine d an dcertifie di naccordanc e wit hth e procedure s prescribe dunde r Referenc e Metho d 9 ar e consistentl y

abl e t o rea dopacit y wit herror s no t exceedin g+ 7. 5 percent base dupo nsingl e set s o f th e averag e o f 2 4 readings . V--- r : •• ; -io*- " I"'-

' Rs>f > •"••"-ne

e Metho d9 includ e th e following : 1 . Anintroductor y

sectio ni s added . Thi s include s a discussio no f th e concep t o f visibl e emissio nreadin gan ddescribe s th e effec t o f variabl e viewin g conditions . Informatio ni s als o presente dconcernin gth e accurac y ofth e metho d notin gtha t th e accurac y o f th e metho dmus t b e take nint o accoun t whe ndeterminin g possibl e violation s o f applicabl e opacit y standards . 2 . Provision s ar e adde dwhic hspecif y tha t th e determinatio no f opacit y re quire s averagin g2 4 reading s take na t 15-secon dintervals . Th e purpos e fo r takin g 2 4 reading s i s bot ht o exten dth e averagin gtim e ove r whic hth e observation s ar e made , an dt o tak e sufficien t reading s t o insur e acceptabl e accuracy . 3 . Mor e specifi c criteri a concernin gobserve r positio nwit hrespec t t o th e su nar e added . Specifically , th e su nmus t b e withi na 140 ° secto r t o th e observer' s back . 4 . Criteri a concernin ga nobserver' s positio nwit hrespec t t o th e plum e ar e added . Specifi c guidanc e i s als o provide dfo r readin gemission s fro m rectangula r emissio npoint s wit hlarg e lengt ht o widt hratios , an dfo r readin gemission s fro m multipl e stacks . Ineac ho f thes e cases , emission s ar e t o b e rea dacros s th e shortes t pat hlength . 

### A-2P.6 0

5 . Provision s ar e adde d t o mak e clea r th e opacit yo f contaminate d wate r o r stea mplume s i s t o b e rea d a t a poin t wher e wate r doe s no t exis t i n condense d form . Tw o specific instruction s ar e provided : On e fo r th e cas e wher e opacit y ca n b e observe d prio r t o th e formatio n o f th e condense d wate r plume , an d on e fo r th e cas e wher e opacit yi s t o b e observe d afte r th e condense d wate r plum e ha s dissipated . 6 . Specification s ar e adde d fo r th e smok e generato r use d fo r qualificatio n o f observer s s o tha t Stat e o r loca l ai r pollutio n contro l agencie s ma yprovid e observe r qualificatio n trainin g consisten t wit hEP Atraining . In developin g thi s regulatio n w e hav e take n int o accoun t th e comment s receive d in respons e t o th e Septembe r 11 , 197 4 (3 9 F R 35852 ) notic e o f propose d rulemakin g whic hpropose d amon g othe r thing s certai n mino r change s t o Referenc e Metho d 9 . Thi s regulatio n represent s th e rulemakin g wit hrespec t t o th e revision s t o Metho d 9 . Th e determinatio n o f complianc e wit happlicabl e opacit ystandard s wil l b e base d o n a n averag e o f 2 4 consecutiv e opacit yreading s take n a t 1 5 secon d intervals . Thi s approac hi s a satisfactor ymean s o f enforcin g opacit ystandard s i n case s wher e th e violatio n i s a continuin g on e and tim e exception s are no t par t o f th e applicabl e opacit ystandard . However , th e opacit ystandard s fo r stea melectric generator s i n 4 0 CF R 60.4 2 an d flui d catalyti c crackin g uni t catalys t regenerator s i n 4 0 CF R 60.10 2 and numerou s opacit ystandard s i n Stat e Implementatio n Plan s specif yvariou s tim e exceptions . ManyStat e an d loca l ai r pollutio n contro l agencie s us e a differen t approac hi n enforcin g opacit ystandard s tha n th e six-minut e averag e perio d specifie d i n thi s revisio n t o Metho d 9 . EP Arecognize s tha t certai n type s o f opacit yviola
tion s tha t ar e intermitten t in natur e requir e a differen t approac hi n applyin g th e opacit ystandard s tha n thi s revisio n t o Metho d 9 . I t . •• :y?': \ = <.- • n t ;.. • pr-r-pr-i

e an additiona l revisio n t c Metho d 9 specifyin g a n alternativ e metho d t o enforc e opacit y standards . I t i s ou r inten t tha t thi s metho d specif ya minimu mnumbe r o f reading s tha t mus t b e taken , suc ha s a minimu mo f te n reading s abov e th e standar d i n ?.n yon e hou r perio d prio r t o citin g a violation . EP Ai s i n th e proces s o f analyzin g svail
abl e dat a and determinin g th e erro r involve d i n readin g opacit yi n thi s manne r an d wil l propos e thi s revisio n t o Metho d 9 a s soo n a s thi s analysisi s completed . Th e Agenc ysolicit s comment s and recommendation s o n th e nee d fo r thi s additiona l revisio n t o Metho d 9 and woul d welcom e anysuggestion s particularl yfro mai r pollutio n contro l agencie s o n ho ww e migh t mak e Metho d 9 mor e responsiv e t o th e need s o f thes e agencies . Thes e action s are

effectiv e o n Novembe r 12 , 1974 . Th e Agenc yfind s goo d caus e exist s fo r no t publishin g thes e action s a s a notic e o f propose d rulemakin g an d fo r makin g the meffectiv e immediatel yupo n publicatio n fo r th e followin g reasons : (1 ) Onl ymino r amendment s ar e bein g mad e t o th e opacit ystandard s whic h wer e remanded . (2 ) Th e U . S . Cour t o f Appeal s fo r th e Distric t o f Columbi a instructe d EP A t o complet e th e reman d proceedin g wit hrespec t t o th e Portlan d cemen t plan t standard s b

yNovembe r 5 , 1974 . (3 ) Becaus e opacit ystandard s ar e th e subjec t o f othe r litigation , i t i s necessar yt o reac ha fina l determinatio n wit hrespec t t o th e basi c issue s involvin g A- 3P.6 1

opacit ya t thi s tim e i n orde r t o properl yrespon d t o thi s issu e wit hrespec t t o suc hothe r litigation . Thes e regulation s ar e issue d udne r th e authorit yo f section s 11 1 and 11 4 o f th e Clea n Ai r Act , a s amende d (4 2 U.S.C . 1857c- 6 an d 9) . Dated : Novembe r 1 , 1974 . Joh n Quarle s Actin g Administrator. "



### A- 4P.6 2

METHO D 9 —VISUA LDETERMINATIO N O F TH E OPACIT YO F

EMISSION S FRO M STATIONAR YSOURCE S Th e curren t Metho d 9 , publishe d i n th e Federa l Register , Volum e 39 , No . 21 9 o n Novembe r12 , 1974 , i s reproduce d below : "Manystationar ysource s discharg e visibl e emission s int o th e atmosphere ; thes e emission s ar e usuall yi n th e shap e o fa plume . Thi s metho d involve s th e determinatio n o fplum e opacit yb yqualifie d observers . Th e metho d include s pro cedure s fo rth e trainin g and certificatio n o fobservers , an d procedure s t o b e use d i n th e fiel d fo rdeterminatio n o fplum e opacity . Th e appearanc e o fa plum e a s viewe d byan observe rdepend s upo n a numbe ro fvariables , som e o fwhic h ma

y b e controllabl e an d some o fwhic h ma yno tb e controllabl e i n th e field . Vari able s whic h ca n b e controlle d t o a n exten t t o whic h the yn o longe rexer t a sig nifican t influenc e upo n plum e appearanc e include : Angl e o fth e observe rwit h respec t t o th e plume ; angl e o fth e observe rwit h respec tt o th e sun ; poin t o f observatio n o fattache d an d detache d stea m plume ; an d angl e o fth e observe rwit h respec t t o a plum e emitte d fro m a rectangula rstac k wit h a larg e lengt h t o widt h ratio . Th e metho d include s specifi ccriteri a applicabl e t o thes e variables . Othe rvariable s whic h ma yno t be controllabl e i n th e fiel d ar e luminescenc e an d colo rcontras t betwee n th e plum e and th e backgroun d agains twhic h th e plum e i s viewed . Thes e variable s exer t a n influenc e upo n th e appearanc e o fa plum e a s viewe d b

ya n observer , an d ca n affec tth e abilit yo fth e observe rt o accuratel y assig n opacit yvalue s t o th e observe d plume . Studie s o fth e theor yo fplum e opacit yand fiel d studie s hav e demonstrate d tha t a plum e i s mos tvisibl e an d present s th e greates t apparen t opacit ywhe n viewe d agains ta contrastin g back ground . I t follow s fro m this , an d i s confirme d byfiel d trials , tha tth e opacit y o fa plume , viewe d unde rcondition s wher e a contrastin g backgroun d i s presen t ca n b e assigne d wit h th e greates t degre e o faccuracy . However , th e potentia l fo ra positiv e erro ri s als o th e greates twhe n a plum e i s viewe d unde rsuc h contrastin g conditions . Unde rcondition s presentin g a les s contrastin g background , th e apparen t opacit yo fa plum e i s les s and . approache s zer o as th e colo ran d luminescenc e contras t decreas e towar d zero . A s a result , significan tnegativ e bia s an d negativ e error s ca n b e made whe n a plum e i s viewe d unde rles s contrastin g conditions . Anegativ e bia s decrease s rathe rtha n increase s th e possibilit ytha ta plan t operato rwil l b e cite d fo ra violatio n o fopacit ystandard s du e t o observe rerror . Studie s have bee n undertake n t o determin e th e magnitud e o fpositiv e error s whic h ca n b e made byqualifie d observer s whil e readin g plume s unde rcontrastin g condition s and usin g th e procedure s se t fort h i n thi s method . Th e result s o f thes e studie s (fiel d trails ) whic h involv e a tota l o f76 9 set s o f2 5 reading s eac h ar e as follows : 1 ) Fo rblac k

plume s (13 3 set s a t a smok e generator) , 100 percen to fth e set s wer e rea d wit h a positiv e error ! o fles s tha n 7. 5 percen topacity ; 9 9 percen t wer e rea d wit h a positiv e erro ro fles s tha n 5 percen t opacity . 

## I Fc ra set , positiv e erro r= averag e opacit ydetermine d byobserver' s 2 5 observa tion s - averag e opacit ydetermine d fro m transmissometer' s 25 recordings . A- 5P.6 3

2 ) Fo r whit e plume s (17 0 set s a t a smok e generator , 16 8 set s a t a coal
fire d powe r plant , 29 8 set s a t a sulfuri c aci d plant) , 9 9 percen t o f th e set s wer e read wit ha positiv e erro r o f les s tha n 7. 5 percen t opacity ; 9 5 percen t wer e read wit ha positiv e erro r o f les s tha n 5 percen t opacity . Th e positiv e observationa l erro r associate d wit ha n averag e o f twenty-fiv e reading s i s therefor e established . Th e accurac yo f th e metho d mus t b e take n into
accoun t whe n determinin g possibl e violation s o f applicabl e opacit ystandards . 1 . PRINCIPL E AND APPLICABILIT Y 1. 1 PRINCIPL E

Th e opacit yo f emission s fro mstationar ysource s i s determine d visuall yb y a qualifie d observer . 1. 2 APPLICABILIT Y

Thi s metho d i s applicabl e fo r th e determinatio n o f th e opacit yo f emission s fro m stationar ysource s pursuan t t o §60.1 1 (b ) an d fo r qualifyin g observer s fo r visuall ydeterminin g opacit yo f emissions . 2 . PROCEDURE S

Th e observe r qualifie d in accordanc e wit hparagrap h3 o f thi s metho d shal l us e th e followin g procedure s fo r visuall ydeterminin g th e opacit yo f emissions . 2. 1 POSITIO N

Th e qualifie d observe r shal l stand a t a distanc e sufficien t t o orovid e a clea r vie wo f th e emission s wit hth e sun oriente d i n th e 140 ° secto r u - hi s back . Consisten t wit hmaintainin g th e abov e requirement , th e observe r shall , a s mur ha s possible , mak e hi s observation s froma positio n suc htha t hi s lin e o f visio n i s approximatel yperpendicula r t o th e plum e direction , an d whe n observin g opacit yo f emission s fromrectangula r outlet s (e.g . roo f monitors , ope n baghouses , noncircula r stacks) , approximatel yperpendicula r t o th e longe r axi s o f th e outlet . Th e observer' s lin e o f sigh t shoul d no t includ e mor e tha n on e plum e a t a tim e whe n multipl e stack s ar e involved , an d i n an

ycas e th e observe r shoul d mak e hi s observation s wit hhi s lin e o f sigh t perpendicula r t o th e longe r axi s o f suc ha se t o f multipl e stack s (e.g . stu bstack s on baghouses) . 2. 2 FIEL D RECORD S

Th e observe r shal l recor d th e nam e o f th e plant , emissio n location , typ e facility , observer' s nam e an d affiliation , an d th e dat e o n a fiel d dat a shee t (Figur e 9-1) . Th e time , estimate d distanc e t o th e emissio n location , approximat e win d direction , estimate d wind speed , descriptio n o f th e sk yconditio n (presenc e and colo r o f clouds) , and plum e backgroun d ar e recorde d o n a fiel d dat a shee t a t th e tim e opacit yreading s are initiate d and completed .



### A- 6P.6 4

2. 3 OBSERVATIONS Opacit yobservation s shal l be made a tth e poin to fgreates topacit yi n tha t portio n o fth e plum e where condense d wate rvapo ri s no tpresent . Th e observe r shal l no t loo k

continuousl ya t th e plume , bu tinstea d shal l observ e th e plum e momentaril ya t 15-secon d intervals . 2.3. 1 ATTACHE D STEA M PLUME S Whe n condense d wate rvapo ri s presen t withi n th e plum e as i t emerge s fro m th e emissio n outlet , opacit yobservation s shal l b e made beyon d th e poin t i n th e plum e a t whic h condense d wate rvapo ri s n o longe rvisible . Th e observe rshal l recor d th e approximat e distanc e fro m th e emissio n outle tt o th e poin ti n th e plum e a t whic h th e observation s ar e made . 2.3. 2 DETACHED STEA M PLUM E Whe n wate rvapo ri n th e plum e condense s and becomes visibl e a ta distinc t distanc e fro m th e emissio n outlet , th e opacit yo femission s shoul d b e evaluate d a t th e emissio n outle t prio rt o th e condensatio n o fwate rvapo ran d th e formatio n o fth e stea m plume . 2. 4 RECORDIN

G OBSERVATIONS Opacit yobservation s shal l b e recorde d t o th e neares t5 percen ta t15 - secon d interval s o n a n observationa l recor d sheet . (Se e Figur e 9- 2 fo ra n example. ) Aminimu m o f2 4 observation s shal l b e recorded . Eac h momentary observatio n recorde d shal l b e deemed t o represen t th e averag e opacit yo f emission s fo ra 15-secon d period . 2. 5 DAT

AREDUCTIO

N Opacit yshal l b e determine d as a n averag e o f2 4 consecutiv e observation s recorde d a t15-secon d intervals . Divid e th e observation s recorde d o n th e recor d shee t int o set s o f2 4 consecutiv e observations . Ase ti s compose d o fan y2 4 consecutiv e observations . Set s nee d no t b e consecutiv e i n tim e an d i n n o cas e shal l tw o set s overlap . Fo reac h se to f2 4 observations , calculat e th e averag e bysummin g th e opacit yo fth e 2 4 observation s an d dividin g thi s sum by24 . I fa n applicabl e standar d specifie s a n averagin g tim e requirin g more tha n 2 4 observations , calculat e th e averag e fo ral l observation s made durin g th e specifie d tim e period . Recor d th e averag e opacit yo n a recor d sheet . (Se e Figur e 9- 1 fo ra n example. ) 3 . QUALIFICATION S AN D TESTIN G 3. 1 CERTIFICATIO N REQUIREMENT S To receiv e certificatio n a s a qualifie d observer , a candidat e mus tb e teste d an d demonstrat e th e abilit yt o assig n opacit yreading s i n 5 percen tincrement s t o 2 5 differen t blac k

plume s and 2 5 differen t whit e plumes , wit h a n erro rno t t o excee d 1 5 percen t opacit yo n an yon e readin g an d a n averag e erro rno tt o excee d 7. 5 percen t opacit yi n eac h category . Candidate s shal l be teste d accordin g t o th e A- 7P.6 5 i l" i


### procedure s describe di nparagrap h3.2 . Smok t ^>.^ . u..« i . . U 

### a ^ KU1J 1 

### grap h3. 2 shal l b e equippe dwit ha smok e mete r whic hmeet s th e re q paragrap h3.3 . Smok e generator s use dpursuan t t o para i mete r whic hmeet s th e requirements ' o f Th e certificatio nshal l b e vali dfo r a perio do f 6 months , a t whic htim e th e qualificatio nprocedur e mus t b e repeate db yanyobserve r i norde r t o retair i certification . i 3.2 . CERTIFICATIO NPROCEDUR E Th e certificatio ntes t consist s o f showin g th e candidat e a complet e ru n o f 5 0 plume s - 2 5 blac k plume s and2 5 whit e plume s - generate db ya smok e generator . Plume s withi neac hse t o f 2 5 blac k and2 5 whit e run s shal l b e presente di nrandom order . Th e candidat e assign s a nopacit yvalu e t o eac hplum e an drecord s hi s observationo na suitabl e form . A t th e completio no f eac hruno f 5 0 readings , th e scor e o f th e candidat e i s determined . I f a candidat e fail s t o qualify, ' th e complet e ru

no f 5 0 reading s mus t b e repeate di nanyretest . Th e smok e test ' ma y b e administere da s par t o f a smok e schoo l o r trainin g program , andma yb e precede d b ytrainin g o r familiarizatio nrun s o f th e smok e generato r durin g whic hcandidate s ar e shownblac k andwhit e plume s o f knownopacity . ' 3. 3 SMOK E GENERATO RSPECIFICATION S Anysmok e generato r use dfo r th e purpos e o f paragrap h3. 2 shal l b e equippe d wit ha smok e mete r installe dt o measur e opacit yacros s th e diamete r o f thejsmok e generato r stack. . Th e smok e mete r outpu t shal l displa yin-stac k opacit ybase d upo na pat hlengt hequa l t o th e stac k exi t diameter , o na ful l 0 t o 10 0 percen t char t recorde r scale . Th e smok e mete r optica l desig nandperformanc e shall | mee t th e specification s show ni nTabl e 9-1 . Th e smok e met e -?:.-•'' ! '-; - calibrate d?. prescribe d-

nparagrap h3.3. 1 prio r t o th e conduc t o f eac hsmok e readin g test . A t th e completio no f eac htest , th e zer o andspa ndrif t shal l b e checke dan di f th e drif t exceed s ± 1 percen t opacity , th e conditio nshal l b e correcte dprio r t o conductin g an

ysubsequen t tes t runs . Th e smok e mete r shal l b e demonstrate da t th e tim e o f installation , t o mee t th e specification s liste di nTabl e 9-1 . |Thi s demonstratio nshal l b e repeate dfollowin g anysubsequen t repai r o r replacemen t o f th e photocel l o r associate delectroni c circuitr yincludin g th e char t recorde r o r outpu t meter , o r ever y6 months , whicheve r occur s first .

TABL E 9- 1 —SMOK E METE RDESIG NAN D PERFORMANC E SPECIFICATION S Paramete r a . Ligh t source b . Spectra l respons e o f photocel l c . Angl e o f vie w d . Angl e o f projectio n Specificatio n Incandescen t lam

p operate da t nomina l rate dvoltage . Photopi c (dayligh t spectra l respons e o f th e huma ney e - referenc e 4.3) . 15 ° maximu mtota l angle . 15 ° maximu mtota l angle . A- 8

### e . Calibratio nerror f . Zer o andspandrif t g . Respons e tim

e 3.3.1 . CALIBRATION +

_3 % opacity , maximum . +

_1 % opacity , 3 0 minutes , < 5 seconds . Th e smok e mete r i s calibrate dafte r allowin ga minimu m o f 3 0 minute s warmu p b y alternatel y

producin gsimulate dopacit y o f 0 percen t an

d10 0 percent . Whe n stabl e respons e a t 0 percen t o r 10 0 percen t i s noted , th e smok e mete r i s adjuste d t o produc e anoutpu t o f 0 percen t o r 10 0 percen t a s appropriate . Thi s calibratio n shal l be repeate dunti l stabl e 0 percen t an d10 0 percen t reading s ar e produce d withou t adjustment . Simulate d0 percen t an d10 0 percen t opacit y value s ma y

be produce db

y alternatel y

switchin gth e powe r t o the ligh t sourc e o nandof f whil e the smok e generato r i s no t producin gsmoke . 3.3. 2 SMOK E METE REVALUATION Th e smok e mete r desig nan dperformanc e ar e t o b e evaluate da s follows : 3.3.2. 1 LIGH T SOURC E Verif yfro m manufacturer' s dat a an d fro m voltag e measurement s made a t th e lamp , a s installed , tha t th e lam p i s operate d withi n + 5 percen to fth e nomina l rate d voltage . 

### 3.3.2. 2 SPECTRAL RESPONS E O F PHOTOCEL L Verif yfro m manufacturer' s dat a tha t th e photocel l has a photopi cresponse ; i.e. , th e spectra l sensitivit yo fth e cel l shal l closel yapproximat e th e standar d spectral-luminosit ycurv e fo rphotopi cvisio n whic h i s reference d i n (b ) o fTabl e 9-1 . 

### 3.3.2. 3 ANGL E O F VIE W Chec kconstructio ngeometr y t o ensur e tha t the tota l angl e o f view o f th e smok e plume , a s seenb y th e photocell , doe s no t excee d15° . Th e tota l angl e o f view may b e calculate dfrom : 9= 2 tan - 1 

### d/2L , wher e e = tota l angl e o f view ; d= th e su

m o f the photocel l diamete r + the diamete r o f the limitingaperture ; an dL = th e distanc e fro m th e photocel l t o th e limitingaperture . Th e limitin g apertur e i s th e poin t i nth e pat hbetwee nth e photocel l an dth e smok e plume wher e th e angl e o f view

i s mos t restricted . I nsmok e generto r smok e meter s thi s i s normall y anorific e plate . 3.3.2. 4 ANGL E OF PROJECTIO N Chec kconstructio ngeometr y t o ensur e tha t the tota l angl e o f projectio no f the lam po nthe smok e plume doe s no t excee d15° . Th e tota l angl e o f projectio n ma y b e calculate dfrom : 9= 2 tan" 1 

### d/2L , wher e 9 = tota l angl e o f projection ; d= th e su

m o f th e lengt ho f the lam pfilamen t + the diamete r o f th e limiting aperture ; andL = distanc e fro m th e lam pt o th e limitingaperture . 

## A- 9•p--|---:t|-rT -



### 3.3.2. 5 CALIBRATIO NERRO Rj Usin g neutral-densit yfilter s o f know nopacity , chec k th e erro r betwee nth e actua l respons e andth e theoretica l linea r respons e o f th e smok e meter . Thi s chec k i s accomplishe db yfirs t calibratin g th e smok e mete r accordin g t o 3.3. 1 an d the ninsertin g a serie s o f thre e neutral-densit yfilter s o f nomina l opacit yo f 20 , 50 , and7 5 percen t i n th e smok e mete r pathlength . Filter s calibrate d[within , + 2 percen t shal l b e used . Car e shoul db e take nwhe ninsertin g th e filter s t o preven t stra yligh t fro maffectin g th e meter . Mak e a tota l o f fiv e nonconjsecutiv e reading s fo r eac hfilter . Th e maximu merror o n anyon e readin g shal l b e 3 percen t opacity . ' ! 3.3.2. 6 ZER O AN D SPANDRIF T Determin e th e zer o andspa ndrif t b ycalibratin g andoperatin g th e smok e generato r i n a norma l manne r ove r a 1-hou r period . Th e drif t i s measure djb y checkin g th e zer o andspa na t th e endo f thi s period . < 3.3.2. 7 RESPONS E TIM E Determin e th e respons e tim e b yproducin g th e serie s o f fiv e simulate d0 percen t and10 0 percen t opacit yvalue s andobservin g th e tim e require dt o jreach stabl e response . Opacit yvalue s o f 0 percen t and10 0 percen t ma yb e simulate db y alternatel yswitchin g th e powe r t o th e ligh t sourc e of f ando n whil e th e smok e generato r i s no t operating . ' 4 . REFERENCE S | 

### 4. 1 Ai r Pollutio nContro l Distric t Rule s andRegulations , Lo s Angele s Count y Ai r Pollutio nContro l District , Regulatio nIV , Prohibitions , Rul e 50 . 4. 2 Weisburd , Melvi nI. , Fiel dOperation s andEnforcemen t Manua l fo r Air, ] U.S , Environmenta l Protect ' 1972 . pp . 4. 1 - 4.36 . - 

### Environmenta l Protectio nAgency , Researc hTriangl e Park , N . C , APTD-1100, ! Augus t 4. 3 Condon , E.U. , andOdishaw , H. , Handboo k o f Physics , McGraw-Hil l Co. , N,.Y. , N.Y . 1958 , Tabl e 3.1 , p . 6-52. "

A-1 0P.6 8

APPENDI XB
Alternativ e Method s fo r Visua l Determinatio n o f th e Opacit yo f Emission s fro mStationar ySource s

Appendi xB contain s introductor ycomment s and detaile d procedure s fo r th e tw o preferre d methods . Th e method s are drafte d i n a regulator yforma t simila r t o tha t o f Metho d 9 .P.6 9

ALTERNATIV E METHOD S FO RVISUA L DETERMINATIO N O F TH E OPACIT YO F EMISSION S FRO MSTATIONAR YSOURCE S O n Novembe r 12 , 1974 , th e Environmenta l Protectio n Agenc y(EPA ) revise d an d repromulgate d Referenc e Metho d 9 (4 0 CF R60 , Appendi xA ) fo r determinatio n b y qualifie d observer s o f th e opacit yo f visibl e emission s fro mstationar ysources . Th e Referenc e Metho d i s applicabl e t o source s subjec t t o standard s o f performanc e promulgate d unde r Section s 11 1 an d 11 2 o f th e Clea n Ai r Act . Referenc e Metho d 9 include s procedure s fo r th e trainin g an d certificatio n o f observers , a s wel l a s fiel d procedure s fo r th e determinatio n o f plum e opacity . Referenc e Metho d 9 specifie s th e determinatio n of-a n averag e opacit yfro m 2 4 consecutiv e opacit yobservation s take n a t 15-secon d intervals . Th e Preambl e t o Referenc e Metho d 9 recognize s tha t certai n type s o f opacit yviolation s tha t are intermitten t i n natur e o r tha t ar e subjec t t o tim e exemption-typ e regulation s requir e a n approac hi n applyin g th e opacit ystandard ; tii.r. : •...:'.\:'- s •..•;• : ; !• ; >. oi th e six-minut e averag e o f Revise d Metho d 9 . Th e Preambl e furthe r state s EPA' s intentio n t o conduc t mor e stud yan d ultimatel yt o propos e alternativ e method s t o Metho d 9 tha t bette r asses s th e complianc e statu s o f suc hsource s o f particulat e emissions . Tw o acceptabl e procedure s fo r determinin g th e opacit yo f intermitten t emission s i n exces s o f a n applicabl e standar d ar e (1 ) byus e o f Metho d 9 , excep t usin g a three-minut e average ; an d (2 ) byaggregatio n o f discret e measurement s mad e a t 15-secon d interval s t o determin e th e accumulate d tim e th e opacit yexceed s th e standar d (frequenc ycoun t method) .



### B-l•: • .. •p |T,„ , . , m, .

To evaluat e thes e procedures , a serie s o ffiel d experiment s wa s conducte d unde rcontrolle d fiel d conditions , usin g ligh tan d dar k visibl e plume s generate d usin g a smok

e generator , an d wit h a transmissomete rmeetin g th e specification s o f Metho d 9 . Durin g thes e evaluatio n tests , panel s o fqualifie d observer s (certifie d byMetho d 9 procedures ) rea d th e generate d plume s i n 5 % opacit yincrement s an d a t 15-secon d intervals . Th e dat a wer e reduce d usin g th e frequenc ycoun tmetho d an d by averagin g fo rvaryin g length s o ftime . Dat a fro m th e earlie rfiel d trial s als o wer e evaluated . Observe rmeasurement s wer e the n compare d t o th e referenc e value s measure d byth e smok e generato rtransmissometer . Overall , 1,88 0 six-minut e dat a set s wer e evaluated . Th e accurac yo fth e three-minut e averagin g method s fo rthes e dat a set s i s as follows :

. 85 % o fth e dat a set s ha d a n erro ro fles s tha n +7.5 % opacity .

. 95 % o fth e dat a set s ha d a n erro ro fles s tha n +11.8 % opacity . Evaluatin g th e accurac yo fth e frequenc ycoun t metho d i s somewha tmore complicated . Acombinatio n o fopacit yerro ran d tim e erro rwa s determine d t o b e th e mos t practica l measur e o fmetho d accuracy , i n keepin g wit h commo n practic e bythos e Stat e an d loca l ai rcontro l agencie s usin g thi s method . Th e opaciit y erro rfacto r(eithe r5 % o r10 % opacity ) i s applie d bysubtractin g i t fro m eac h 15 - secon d readin g an d the n countin g th e numbe ro f15-secon d reading s abov e the | applicabl e standard . Th e tim e erro rfacto r(1 5 seconds/six-minut e reading ) i s applie d b yrequirin g th e emission s i n exces s o fth e standar d t o b e recorde d fo r i i th e tim e exemptio n perio d specifie d i n th e regulatio n plu s th e adde d tim e erro r period . Fo rth e 1,88 0 dat a set s evaluated : .85 % o fth e dat a set s ha d n o positiv e bia s whe n a 5 % opacit yerro rfacto r an d 1 5 seconds/six-minut e readin g tim e erro rfacto rwer e used . .95 % o fth e dat a set s had n o positiv e bia s whe n a 10 % opacit yerro rfacto r an d 1 5 seconds/six-minut e readin g tim e erro rfacto rwer e used . B- 2P.7 1

I n th e abov e statements , "n o positiv e bias " mean s tha t th e observe d tim e abov e th e standar d (afte r erro r factor s wer e adde d in ) wa s alway s les s tha n th e transmissomete r tim e abov e th e standard . Th e accurac yo f eac hmetho d mus t b e take n int o accoun t whe n determinin g possibl e violation s o f opacit ystandards . Th e three-minut e averag e i s applicabl e t o thos e intermitten t emissio n source s subjec t t o a n average d opacit ystandard , o r whe n th e three-minut e averagin g metho d i s specificall yreferre d t o i n th e regulation . Th e frequenc ycoun t metho d i s applicabl e t o al l tim e exemption-typ e regulations , bot hfo r intermitten t and mor e continuou s plum e types . Th e on e exceptio n i s fo r si xminute s pe r hou r tim e exemptio n regulations ; i n thi s case , a six-minut e average d readin g shoul d b e use d rathe r tha n th e frequenc ycoun t metho d i f Metho d 9 i s specifie d b yregulatio n a s th e metho d t o b e used . 1. 0 PRINCIPL E AND APPLICABILIT Y 1. 1 PRINCIPL E Th e opacit yo f emission s fro m stationar ysource s i s determine d visuall yb ya qualifie d observer . 1. 2 APPLICABILIT Y Thi s metho d i s applicabl e fo r th e determinatio n o f th e opacit yo f emission s fro mstationar ysource s wit hintermitten t plume s and fo r al l plum e type s wher e tim e exemptio n regulation s apply . 'Intermitten t plume s are define d i n Sectio n 2.6. 1 o f thi s method . 2. 0 PROCEDURE S A n observe r qualifie d i n accordanc e wit hSectio n 3 o f Referenc e Metho d 9 (4 0 CF R 60 , Appendi xA ) shal l us e th e followin g procedure s fo r visuall ydeterminin g th e opacit yo f emission s fro mstationar ysource s wit hintermitten t plumes . B- 32. 1 POSITIO N

Th e qualifie d observe r shal l stan d a t a distanc e sufficien t t o provid e a clea r vie wo f th e emission s wit hth e sun oriente d i n th e 140 ° secto r t o hi s o r i he r back . Consisten t wit hmaintainin g th e abov e requirement , th e observer ? shall , a s muc ha s possible , mak e hi s o r he r observation s fro ma positio n suc htha t hi s o r he r lin e o f visio n i s approximatel yperpendicula r t o th e plum e direction , and , whe n observin g opacit yo f emission s fro mrectangula r outlet s (e.g. , roo f monitors , ope n baghouses , noncircula r stacks) , approximatel yperpendicula r t o th e longe r axi s o f th e outlet . Th e observer' s lin e o f sigh t shoul d no t includ e mor e tha n on e plum e a t a tim e whe n multipl e stack s ar e involved , and , i n anycase , th e observe r shoul d mak e hi s o r he r observation s wit hhi s o r he r lin e o f sigh t perpendicula r t o th e longe r axi s o f suc ha se t o f multipl e stack s (e.g. , stub stack s o n baghouses) . 2. 2 FIEL D RECORD S Th e observe r shal l recor d th e nam e o f th e plant , emi i,sio n locoucn , typ e o f facility , observer' s nam e and affiliation , and th e dat e o n a fiel d dat a sheet . Th e time , estimate d distanc e t o th e emissio n location , approximat e win d direction , estimate d win d speed , descriptio n o f th e skyconditio n (presenc e and colo r o f clouds) , and plum e backgroun d ar e recorde d o n a fiel d dat a shee t a t th e tim e opacit yreading s ar e initiate d and completed . 2. 3 POIN T O F OBSERVATIO N Opacit yobservation s shal l b e mad e a t th e poin t o f greates t opacit yi n tha t portio n o f th e plum e wher e condense d wate r vapo r i s no t present . 2.3. 1 ATTACHE D STEAMPLUME S Whe n condense d wate r vapo r i s presen t withi n th e plum e a s i t emerges ' fro m th e emissio n outlet , opacit yobservation s shal l b e mad e beyon d th e poin t i n th e B- 4P.7 3

plume a t whic hcondense dwate r vapo r i s no longe r visible . Th e observe r shal l recordth e approximat e distanc e fro m th e emissio noutle t t o th e poin t i nth e plume a t whic hth e observation s ar e made . 2.3. 2 DETACHE DSTEA M PLUME S Whe nwate r vapo r i nth e plume condense s an dbecome s visibl e a t a distinc t distanc e fro

m th e emissio noutlet , th e opacit y o f emission s shal l b e evaluate da t th e emissio noutle t prio r t o th e condensatio no f wate r vapo r an dth e formatio n o f th e stea

m plume . 2. 4 OBSERVATION

PROCEDURE S 2.4. 1 FREQUENC YCOUN T METHO D Thi s metho d applie s t o al l source s subjec tt o tim e exemptio n regulations , excep t wher e th e tim e exemptio n perio d i s fo rsi xminutes/hou rand Referenc e Metho d 9 i s specifie d a s th e require d readin g method . Th e observe rshal l no t loo k continuousl ya t th e plume , bu tinstea d shal l observ e th e plum e momentaril y a t 15-secon d intervals . 2.4. 2 THREE-MINUTE AVERAGING METHO D Thi s metho d applie s t o intermitten temissio n plume s fro m source s subjec t t o average d opacit yregulations . Intermitten temission s ar e define d i n Sectio n 2.6.1 . Th e observe rshal l no t loo k continuousl ya tth e plume , bu t instea d shal l observ e th e plum e momentaril ya t15-secon d intervals . 2. 5 RECORDINGOBSERVATION S 2.5. 1 FREQUENC YCOUN T METHO D Opacit yobservation s shal l b e recorde d t o th e neares t5 percen ta t15-secon d interval s o n a n observationa l recor d sheet . (Se e Figur e B- l fo ra n example. ) B- 5FIGURE B- l Dat a Reductio n an d Computatio n Form

fo r Frequenc yCoun t Procedur e r , r . . . „,,,, -

vl&itJL e civi.ibiO.N i ut36tKV M I IU M r-L'rti. i SOURC E I-.AM C OBSERVATIO N OAT C ST AR TTIM E STO PTIM E AOORES S SC C MI N 1 3 3 0 \se c M1N \

SOURC E I O NUMBE D POOCCS S EQUIPMEN T CONTRO L EQUIPMEN T OPERATIN G MOD E OPERATIN G MOD E DESCRIB E EMISSIO N POIN T STAR T 1 EIGH TABOV E GROUN D LEVE L DISTANC E FRO M OBSERVE R HEIGH TRELATIV E T O OBSERVE R DIRECTIO N FRO M OBSERVE R DESCRIB E EMISSION S STAR T EMISSIO N COLO R STAR TS T PLUM E TYPE : CONTINUOU S 0 FUGITIV E O INTERMITTEN TQ WATE R OROPLET S PRESENT N O a YE S a I F WATE R DROPLE TPLUME : ATTACHE D O DETACHE D Q POIN TI N TH E PLUM E A TWHIC H OPACIT YWA S DETERMINE D STAR TSTO P DESCRIB E BACKGROUN D DACKAnoUN O COLO R STAR TSTO P SK YCONDITION S STAR TSTO P WIN D SPEE D STAR TSTO P WIN O DIRECTIO N STAR TSTO P AMBIEN TTEMP . STAR T WE TBUL B TEMP . RH , percen t SOURC E LAYOU TSKETC H DRA WNORT H ARRO W



# o

XEMISSIO N POIN T

SU N < > WIN D PLUM E AN O STAC K

COMMENT S OBSERVER S POSITIO N AVERAG E OPACIT YFO R HIGHES TPERIO D X0.2 5 = MINUTF. S EXCES S -.4 0 SU N LOCATIO N LIN E RANG E O F OPACI TYREADING S MINIMU M > 1 AXIMU M OBSERVER' S NAM E (PRINT ) OBSERVER' S SIGNATUR E OR G ANI Z ATIO N I HAV E RECEIVE D ACOP TO TTHES E 0*-*CIT TOBSERVATION S SIGNATUR E CERTIFIE D B Y ;£»lHE O B Y 

### B-6Eac hmomentar yobservatio n recorde d shal l b e deeme d t o represen t th e averag e

opacit yo f emission s fo r a 15-secon d period . • 2.5. 2 THREE-MINUT E AVERAGIN GMETHO D Opacit yobservation s shal l b e recorde d t o th e neares t 5 percen t a t 15-secon d interval s o n a n observationa l recor d sheet . (Se e Figur e B- 2 fo r a n example. ) Eac hmomentar yobservatio n recorde d shal l b e deeme d t o represen t th e averag e opacit yo f emission s fo r a 15-secon d period . 2. 6 DATAANALYSI S 2.6. 1 DETERMINATIO NO F PLUM E TYP E Determin e th e longes t continuou s tim e tha t th e opacit yobservatio n a s recorde d exceede d th e applicabl e opacit ystandards . I f thi s tim e wa s les s tha n si xminutes , th e emission s shal l b e considere d intermittent . 2.6. 2 DAT AANALYSI S (FREQUENC Y COUN T METHOD ) Coun t th e numbe r o f reading s wit hopacit yabov e th e applicabl e standard , and multipl ytha t numbe r b y0.2 5 t o determin e th e minut-v . j •.-. , ; : ^ • , : r>-.^ . th e standard . 2.6. 3 DAT AANALYSI S (THREE-MINUT E AVERAGIN GMETHOD ) Opacit yshal l b e determine d a s a n averag e o f 1 2 consecutiv e observation s recorde d a t 15-secon d intervals . Divid e th e observation s recorde d o n th e recor d shee t int o set s o f 1 2 consecutiv e observations . Ase t i s compose d o f sny1 2 con secutiv e observations . Set s nee d no t b e consecutiv e i n tim e and i n n o cas e shal l tw o set s overlap . Fo r eac hse t o f 1 2 observations , calculat e th e averag e b ysum min g th e opacit yo f th e 1 2 observation s and dividin g thi s su mb y12 . Recor d th e averag e opacit yo n a recor d sheet . 2. 7 OBSERVE R CERTIFICATIO NREQUIREMENT S Al l observer s shal l b e certifie d accordin g t o th e procedure s o f Section s 3.1-3.3 , Referenc e Metho d 9 . B- 7 •FIGURE B-2 Dat a Reductio n an d Computatio n Form

fo r Three-Minut e Averagin g Procedur e P.7 6
•T i I"" '

VISIbL e ei.ll!>S>ilvi\ i UdbcriVA l IU M H-t-rti. i SOURC E NAM E AOORES S

CIT YJSTA7 C 1 PHON E - * I P SOURC E I D NUMBE D PROCES S EQUIPMEN T CONTRO L EQUIPMEN T OPERATIN G MOD E OPERATIN G MOO C DESCRIB E EMISSIO N POIN T STAR TSTO P HEIGH TABOV E GROUN D LEVE L STAR TSTO P DISTANC E FRO M OBSERVE R STAR TSTO P HEIGH TRELATIV E T O OBSERVE R STAR TSTO P DIRECTIO N FRO M OBSERVE R STAR TSTO P DESCRIB E EMISSION S STAR TSTO P EMISSIO N COLO R STAR TSTO P WATE R DROPLET S PRESENT -

N O 0 YE S a PLUM E TYPE l CONTINUOU S 0 FUGITIV E O INTERMITTEN T0 I F WATE R DROPLE TPLUME : ATTACHE D O DETACHE D O POIN TI N TH E PLUM E A TWHIC H OPACIT YWA S DETERMINE D STAR TSTO P DESCRIB E BACKGROUN D STAR TSTO P BACKGROUN D COLO R STAR TSTO P WIN D SPEE. ? STAR TSTO P AMBIEN TTEMP . STAR TSTO P S K YCONDITION S STAR TSTO P WIN D OlRfc.CT.O N STAR TSTO P W C TBUL B TEMP . RH . percen t
SOURC E LAYOU TSKETC H DRA WNORT H ARRO W



# •o

S U N < > AIN O ^ PLUM E AN O STAC K<X Z , ^OBSERVER S POSITIO N

^^^ 0 **'^ ^140-* ^ ^^^-..w ^ S U N LOCATIO N LIN E COMMENT S

1 HAV E RECEIVE D ACOH fO F Tt- t E S E OPACIT YOBSC->V»TiOh S SIGNATUR E TITL E lOAT l OBSERVATIO N DAT E
MIN \ •
2 J
4 s c
7 8 •.
t o 1 1 I z 1 3

* 4 1 S 1 * 1 7 t S i n 2 0 2 1 2 2 2 3 2 4
2 S
2 « 2 7
2 8 2 9 3 0 0 1 5 j 3 0 STAR TTIM E

* 5

AVERAG E OPACIT YFO R HIGHES TPERIO D Mltt V 0 3 , j » 1

3 3 3 4
3 3
3 C 3 7 1 1 3 9
4 0 4 1
4 2 4 3
4 4

« S 4 4
4 7 4 8 STO P TIM E

I s 3 0

_••. ; i . i _

. • t> 2 S 3 5 4

» S 5 K 5 7 S S 4 » C O NUMBE R O F READING S A B

•» . wr.R E RANG E O F OPACl TYREAOlNG S MINIMU M MAXIMU M I S
1 j

1 i 1 J

•' ! !
;

1 1 1 1

r u e |

OBSERVER' S NAM E IPRlNT I > OBSERVER' S SIGNATUR E DAT E ORCANt Z ATIO N CERTIFIE D B Y VCRI fIC O B Y

- DATE .
O A T
B- 8P.7 7

APPENDI XC Summar yo f Genera l Opacit yRegulation s

(b yRegion )Summar yo fr.--<-••-• " o p ;•,.- :

J-J i.cjglon ; j lation s STATE

Ne wJerse y Ne wYor k Puert o Ric o Delawar e Distric t o f Columbi a Marylan d Pennsylvani a Alleghen yCt y Virgini a Wes t Virgini a OPACIT Y

LIMIT 2 TIM E

EXEMPTIO N REGIO N READIN GMETHO D SPECIFIE D I NREGULATION S



### I Connecticu t M a i n e 1 stac k wit h 2 o r mor e source s o r Massachusett s Ne wHampshir e Rhod e Islan d Vermon t Afte r 4/30/7 0 20%/40 %



### 20 % 40 % 80 % 20%/40 % 

### 20 % 20 % 40%/60 % 20%/60 % 5 min./h r

5 min./h r 2 0 min./h r 1 0 min./h r 6 min./h r 3 min./h r 3 min./h r 6 min./h r Metho d 9 Metho d 9 Metho d 9 Metho d 9 

### I I 20 % 3 min./3 0 min . 20 % 20%/60 % 4 min.'/3 0 min . Metho d 9 , minimu m30-minut e readin g 

### II I 20 % 0%/40 % 0%/20 % Metro/Rura l 20%/60 % 20%/60 % 20%/60 % 20%/40 % 3 min./h r O R

1 5 min./2 4 h r 2 min./h r O R 1 2 min./2 4 h r 3 min./h r 3 min./h r 6 min./h r 5 min./h r Metho d 9 , excep t dat a reductio n sectio n



### 1 Fro m"Opacit yRegulations : Summar yo f Re v Environmenta l Services , Inc . fo r Stationa, . Metho d 9 , excep t som e source s instan
taneou s reading s Metho d 9
^on s an d Rulemakin g Status" , prepare d byPacifi c Sourc e Complianc e Division , EPA , Februar y18 , 1983 . Wher e tw o opacit ylimit s ar e given , th e SP . >n d i s a "cap " o r maximu mopacit yneve r t o b e exceeded ; "Connecticut" , forexampleT-aMows
- 5-minutes/hour-of
—emission s -grea t er--than-20%-but
les s tha n 40% ; n o readin g abov e 40 % i s allowed . 

### C- 1STAT E Alabam a Jefferso n Ct y Florid a Georgi a Kentuck y existin g ne w Mississipp i Nort h CaroMn a befor e 7/01/7 1 afte r7/01/7 1 Sout h Carolin a (N o Boiler s (befor e 2/71 ) (afte r2/71 ) Tennesse e attainmen t nonattainmen t Illinoi s Indian a attainmen t nonattainmen t Lake Ct y(prop ) Michiga n propose d Minnesot a existin g ne w Ohi o OPACIT Y LIMIT 2 2U%/40 % 20%/40% 20 % 40 % 40 % 20 % 40 % 40 % 20 % proces s rule ) 40 % 20 % 20 % 10 % 30%/60% 30%/60% 40%/60% 30 % 20%/40% 20%/27% 20%/40% 20 % 20%/60% TIM E

EXEMPTIO

N 6 min./h r 6 min./h r

5 min./h r 2 0 min./2 4 5 min./h r 2 0 min./2 5

5 min./h r O R

h r O R h r

O R 2 0 min./2 4 h r 5 min./h r 2 0 min./2 4

. 8 min./h r 1 5 min./h r 1 5 min./h r 3 min./h r 6 min./h r 4 min./h r 5 min./h r O R

h r

C REGIO N I V

V

2 READING METHO D SPECIFIE D I N REGULATION
Metho d 9 , readin g tim e specifie d Metho d 9 Metho d 9 , wit h exception s fo rspecifie d source s

Metho d 9

6-minut e average , excep t fo rintermitten t emission s (frequenc ycount ) Metho d 9 , excep t fo riro n an d stee l Metho d 9 Metho d 9STAT

E Wisconsi n befor e 4/01/7 2 afte r4/01/7 2 OPACIT Y LIMIT 2 40 % 20 % TIM E

EXEMPTIO N REGIO N

V V I READIN G METHOD SPECIFIE D I N REGULATIO N

Metho d 9 Arkansa s befor e 1/30/7 2 40 % afte r 1/30/7 2 20 % Louisian a 20 % Ne w Mexic o 20 % Oklahom a 20 % Texa s befor e 1/31/7 2 30 % afte r1/31/7 2 20 % flo w>100,00 0 acf m 15 % 5 min./h rO R 1 5 min./2 4 h r 6 min./h r Method 9 Method 9 , excep t10-minut e averag e Method 9 , excep t 5-minut e averag e 

### TT T Iowa Kansa s existin g ne w Missour i Kansa s Cit y Out-of-Stat e existin g ne w Springfield Gree n Ct y existin g ne w St . Loui s Nebraska Ttetho d 9 Method 9 Ringelman n Char t t o b e used , minimu m o fone-hou rreadin g 40 % 40 % 20 % 20%/60 % 40%/60 % 20%/60 % 40%/60 % 20%/60 % 20%/40 % 20 % 6 min./h r

6 min./h r 6 min./h r 6 min./h r 6 min./h r 6 min./h r Ringelman n Char tt o b e used , minimu m o fone-hou rreadin g Method 9 C-3

o o oOPACITY LIMIT 2 TIM E

EXEMPTIO N STAT E REGIO N READIN G METHOD SPECIFIE D I N REGULATIO N T U T Colorad o 20 % Montan a befor e 11/23/6 8 40 % afte r 11/23/6 8 20 % Nort hDakot a existin g 40%/60 % new 20%/40 % Sout hDakot a 20%/60 % Utah20 % Wyom i n g existin g 40 % ne wsingl e sourc e 20 % 6 min./h r

6 min./h r 3 min./h r Metho d 9 , excep t whe n intermitten t emissions , exclud e period s o fn o emission s
Metho d 9

T X Ar i zon a existin g 40 % new/nonpoin t source s 20 % Californi a 40 % Ba y Are a 20 % Sa nBernardin o 20 % SanDieg o 20 % Sout hCoas t 20 % Hawa i i existin g 40 % new 20 % Nevad a 20 % 3 min./h r 3 min./h r 3 min./h r 3 min./h r 3 mjn./h r 3 min./h r Metho d 9

Alask a 20 % 3 min./h r Idah o 20 % 3 min.h r Orego n befor e 6/01/7 0 40 % 3 min./h r afte r6/01/7 0 20 % 3 min./h r Washingto n 20 % 3 min./h r Revise d Metho d 9

C- 4

- o c oUnite d Slate s

Environmenta l Protectio n Agenc y Offic e o l Ai rOualit yPlannin g an d Standard s Stationar ySourc e Complianc e Divisio n Washingto n D.C . 2046 0 Officia l Busines s Penalt yfo rPrivat e Us e S30 0 Publicatio n N o Specia l Repor t Postag e an d Fee s Pai d Environmenta l Protectio n Agenc y EPA33 5

Ifyou raddres s I s incorrect , pleas e chang e o n th e nbov e label ; tea roff ; an d retur n to th e above address . Ifyo u d o no l desir e l o continu e receivin g thi s technica l repor t series . CHEC KHER E D ; tea rof flabel ; an d retur n I t to th e above address .