# OAR Box 1313 PreppedbyLaTeiaShed



### Document

Number: 

# 57 ) ll-B-3 1 Docket Number: 

# A-88-0 2

Printed 6/12/20089:03:29AM Sheet 57 of 99 P. 1- P. 2 

## A-88-02 / ^ \ UNITE D STATE S ENVIRONMENTA LfAnd ySmit h (MD-13) | kMK. 1 Office ofAi rQualityPlannin g a.. « . \lSZ*J

Researc h Triangl e Park , Nort h Carolin a2771 1 DEC 1 7 198

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7; ' : . \r. , , \ 0 , '. - -'•' • MEMORANDUM' nXL— \ „.Z.- - • """"* " SUBJECT : Screening Metho d Result s fromRol l Technology

Corporatio n FROM : Frank R . Clayyy^LL Emissio n Measuremen t Branc h TO : Chromiu

mElectroplater s Genera l Fil e Th e screening metho d sample s take na t Rol l Technology Corporatio n (formerl yCarolin a Platers ) ar e th e bes t i n th e serie s t o b e performe d b yth e Emissio n Measuremen t Branch . Sampl e result s ar e al l th e same orde r o f magnitud e an d ther e appear s t o b e a modicu mo f consistenc yt o th e data . Whil e th e degre e o f accurac yo f th e metho d i s no t wha t i s desired , ther e ar e step s tha t ca n b e take n t o improv e accuracy , and th e effor t is , a t least , encouraging . I t appear s tha t severa l o f th e earlie r problem s wit hth e metho d hav e bee n solved . Th e waitin g perio d betwee n sampl e collectio n an

d sampl e result s ha s bee neliminate d b yperforming sampl e analysi s o n site . I t als o appear s tha t problem s du e t o poo r sampl e recoverytechniqu e hav e bee neliminate d a s well . Th e majo r proble mtha t remain s i s tha t o f sampl e volume . An effor t wa s mad e prio r t o th e tes t a t Rol l Technologyt o insur e accurat e sampl e volumes . Befor e th e test , al l Thomas® pump s wer e run fo r on e hou r whil e being connecte d t o a we t tes t meter . Th e sampling apparatu s (cassett e filte r o r Teflon® tubing ) wa s als o connecte d t o th e pump . We t tes t mete r volume s wer e determine d an d correcte d fo r temperatur e an d pressur e t o ascertai n th e standard cubi c fee t pe r hou r sampling rate . Th e rotamete r adjustmen t knob s wer e the nfixed int o positio n b yusing silicon e rubbe r cement . Th e sampl e volume s determine d i n th e laboratorywer e use d fo r fiel d calculation s o f chromiu m concentration s fro

m screening metho d runs . Upo n retur nfro mth e field , th e pump s wer e run agai ni n th e laboratoryt o se e i f th e sampl e volume s wer e unchanged . Unfortunately , the ywer e not , an d th e tru e volume s sample d i n th e fiel d remai nunknown .

/ •P. 3

Althoughth e tru e volume s sample d i nth e fiel d remai n unknown , some o f th e pump s wer e relativel yclos e whe n a compariso n wa s mad e betwee n th e initia l volum e an d th e pos t tes t volume . Th e closes t inle t numbe r wa s 2 % high , an d th e closes t outle t numbe r wa s 3 % low . (Thi s compariso nuse s th e initia l number s a s th e standard o r numerator. ) Th e larges t variatio nfo r the inle t pump s wa s 53 % lowwhil e th e greates t variatio na t th e outle t wa s 47 % low . Thre e o f th e eigh t pump s use d fo r th e screening sample s wer e fairl yclos e i n pretes t an d post-tes t volumes . On e wa s a t th e inle t an

d tw o wer e a t th e outlet . I f i t i s possibl e t o conside r dat a fromthes e thre e pump s a s goo d (whichi t probabl yi s not) , the n comparing thes e number s wit hth e Metho d 13- B value s maygiv e some indicatio n a s t o ho waccurat e th e screening metho d is . Th e accurac yrang e o f th e inle t pum p varie d fro

m84 % belo w the Metho d 13- B numbe r t o 395 % abov e th e 13- B number . Th e averag e o f th e positiv e an d negativ e percen t value s i s 73.7 . Th e absolut e averag e i s 112.8 . Eithe r way , th e value s ar e something greate r tha n th e desire d accurac yo f ±50% . A t th e outlet , two o f th e pump s ha d volume s afte r th e tes t tha t wer e clos e t o th e origina l volume s determine d prio r t o th e test . Emissio n number s determine d fro mthes e pump s varie d fro m •31.0 % t o +121 % fo r on e o f th e pump s an d 5.7 % t o 119.2 % fo r th e othe r pump . Th e averag e absolut e value s fo r thes e tw o pump s wer e 54. 9 an d 54 % respectively , an d th e averag e o f th e value s wa s 42. 5 an d 54 % respectively . During th e las t ru

no f th e test , tw o spar e pump s wer e operate d a t th e outle t i n additio n t o th e four regula r pumps . Th e spar e pump s wer e ru n fo r 29 2 minute s ( 4 hr s 5 2 minutes) . Thes e pump s di d no t incorporat e surg e tank s o r rotameter s a s use d on th e regula r screening trains , bu t simpl yran a t maximu m capacit yduring th e run . Tapere d tube s wer e use d fo r sampl e extraction , an

d whil e th e spar e pump s wer e simila r insize , on e pum p sample d a volume abou t te n time s tha t o f th e other . Withou t a surg e tank onth e inle t sid e o f the pump , th e ne t effec t o f th e pum

p i s t o extrac t a sample , bu t i n the process , th e pum p pulse s an

d puff s i n th e inle t direction . Thi s ma ymak e i t difficul t t o determin e th e directio no f flo wo f the pum

p an d i s probabl yth e reaso n tha t on e o f tw o pump s tha t sample d a t maximu mvolume had th e flowdirectio nmarke d backwards . A s a resul t o f thi s mismarking o f th e pump , th e pum p wa s hooke d u

p .

SLP. 4

backwards . Thus , ambien t ai r wa s being pumpe d int o the outle t stac k instead o f being extracte d fro mit . Nevertheless , the sampl e collecte d fro mthi s trai n wa s withi n75 % o f th e rea l concentratio n determine d fro m th e 13- B trai nan d wa s lowb

yonl y 25% . Th e othe r pump , throughextracting a smalle r sample , sample d i n th e righ t directio nan d wa s onl y2 % greate r tha nth e rea l (13-B ) number . Dat a fromth e tw o unrestricte d pump s wer e base d o na sampl e rat e determine d i n th e la bfro m 1 5 minute s o f pum p operation . During th e test , thes e tw o pump s ran fo r ove r four hours , s o a 15-minut e run mayno t hav e give na n accurat e sampling volume . Th e variation , however , woul d no t hav e bee nsufficien t t o chang e th e dat a significantly . Thus , th e pum p tha t ble wambien t ai r int o th e stac k provide d some o f th e mos t accurat e dat a o f all . Fro mth e abov e discussio nof

- th e tw o pumps , i t i s possibl e t o conclud e tha t i t i s mor e accurat e t o extrac t a sampl e fro mth e stac k rathe r tha n t o blo wambien t ai r int o i t i f th e determinatio n o f chrome 6 concentration s i s th e goal . Thi s i s jus t anothe r wayi n whic hscienc e work s fo r yo u her e a t the Unite d State s Environmenta l Protectio nAgency . I f th e percen t erro r o f th e screening runconcentration s i s averaged , i t i s possibl e t o se e howclos e th e screening metho d come s overal l t o th e concentratio ndetermine d fro mth e Metho d 13- B trains . Th e averag e an d absolut e averag e have bee n determine d fo r eac hlocatio nusing th e two set s o f Thoma s ®pum p volumetri c flowrate s determine d i nth e labbot hbefor e an d afte r th e test . A t th e inlet , th e averag e erro r o f th e screening metho d during th e tes t whe n compare d t o the 13- B concentration s wa s +59.6% . Th e valu e o f th e absolut e averag e wa s +93% . Afte r the tes t (an

d using post-tes t sampling volumes ) th e averag e erro r a t the inle t wa s 143 % an d th e valu e o f th e absolut e averag e wa s 172.5% . At th e outlet , th e average s looke d muc hbetter . Th e averag e erro r o f th e screening metho d during th e test , whe n compare d wit h the 13- B concentrations , wa s +40.3% . Th e valu e o f the absolut e averag e wa s 49.2% . Afte r th e tes t (an d using post-tes t sampling volumes ) th e averag e erro r a t th e outle t wa s 32.4 % whil e th e valu e o f th e absolut e averag e wa s 43.9% .P. 5

Th e rang e o f th e number s varie d quit e a bit . Fo r th e inle t locatio n during th e test , percent s varie d fro ma higho f +404 % to . a lo wo f -87.1% . Usin g th e volume s determine d afte r th e test , inle t value s varie d fro ma higho f 787.4 % t o a lowo f 83.9% . A t th e outlet , th e rang e wa s smaller . During th e test , the percent s varie d fro ma higho f 125.4 % t o a lowo f -30.8% . Using sampl e volume s determine d i n th e labafte r th e test , value s range d fro

m a higho f +121 % t o a lowo f -40.7% . Clearly , th e inle t number s ar e les s accurat e tha nth e outle t numbers . Normally , thi s woul d no t b e expecte d sinc e inle t concentration s ar e highe r tha nth e outle t an d a large r sampl e i s usuall ymor e accurate . Ther e mayb e man yreason s fo r thi s anomaly . Th e inle t locatio nwa s verypoo r an d di d no t mee t the criteri a o f Referenc e Metho d I . I t i s als o possibl e tha t th e poin t o f averag e velocit ywa s no t sampled . Th e outlet , onth e othe r hand , wa s an idea l locatio n wit ha bette r velocit yprofile . A t th e outlet , eve n a poin t tha t wa s no t o f averag e velocit y woul d probabl ygiv e goo d results . Fo r th e nex t phas e o f thi s project , some procedura l change s wil l b e made . First , n o sampl e wil l b e take nwithou t determining tha t th e sampl e poin t represent s a poin t o f averag e velocity . Second , onl ysample s using tapere d tubing wil l b e collecte d an d tubing holder s wil l b e modifie d t o insur e tha t th e tubing face s directl yint o th e stac k flows . Third , onl yhypodermi c needle s encase d i n epox

ywil l b e use d a s flowregulating devices . Needl e gaug e wil l b e chose n base d o nvelocitie s determine d o nth e pretes t surveyvisit . Fourth , pum p volume s wil l b e determine d i n th e labbefor e an

d afte r th e tes t wit heac hpum p i nit s sampling configuration . Fifth , th e same sampl e recoveryprocedure s tha t wer e use d i n Greenville , SC , wil l b e use d again . Fo r th e nex t test , onl ytapere d tubing wil l b e use d t o collec t th e samples . Thi s i s no t becaus e th e tapere d tubing i s bette r fo r collecting a sampl e than th e cassett e filter , bu t i t i s easie r t o use . O n th e upcoming test , th e goa l wil l b e t o achiev e reproducibilit yfirs t an d accuracysecond . Usin g al l tapere d tubing sample s wil l als o giv e a bette r statistica l number . Hypodermi c needle s giv e accurat e an d reproducibl e volume s i n th e la b- eve n whe n use d wit hour wornou t pumps . I t i s possibl e t o selec t on e o f thre e needl e gauge s t o sampl e withi n± 30 % isokineti c o f th e rang e o f flowencountere d i nchromiu mplating operation s (Th

e gaug e siz e assume s a 1/8 " diamete r tapere d tube) . Acassett e filte r wil l b e use d a s a protectiv e devic e fo r th e

/ •P. 6

hypodermi c needle , an d gaug e siz e fo r th e nex t tes t wil l b e determine d whe n th e tes t sit e i s selecte d an d th e pretes t survey ha s bee n completed . Prio r t o th e test , Thomas® pump s wil l b e checke d fo r sampl e volume s i nth e tes t apparatu s configuration , an d during th e 13- B tes t run s a t th e facility , anattemp t wil l b e mad e t o ge t 8 on e hou r sample s a t bot hth e inle t an d outle t locations . Thi s wil l provid e a tota l o f 2 4 sample s a t eac h location . Upo n retur n t o th e lab , Thomas ® pump s wil l agai nb e checke d fo r sampl e volume . I f th e upcoming tes t wor k i s successful , ther e ar e some question s tha t stil l remain . Ho wspecifically , wil l th e screening metho d b e used ? Wil l ther e b e a specificatio n a s t o tank loading an

d ampere s tha t mus t b e me t befor e th e screening metho d ca n b e used , an d lastly , i f th e techniqu e i s successful , ho wmuc hadditiona l testing wil l b e neede d t o showtha t th e metho d i s accurate ?

cc : John Brow

n (MD-19 ) Bil l DeWee s (Entropy ) Bil l Grimley(MD-19 ) Gai l Lacy(MD-13 ) Robi n Segal l (Entropy ) Rand yStraight . (MRI ) A l Vervaer t (MD-13 ) And y Smit h(MD^13 )

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