## CALPIN E TW O ATLANTI C WI-. M I THIR D FLOO R BOSTON . MASSACHUSETT S 0211 0 617.723.720 0 617.723.763 5 (MAI N FAX ) Februar y 20 , 200 4 Kare n L . Rega s DEP/BWP/Busines s Complianc e Divisio n On e Winter Street, 8t h Floo r Boston , M A 0210 8 Re : Propose

d Changes t

o 31 0 CM R7.0

0 Dea r M s Regas : Th e purpos e o f

thi s letter

i s to submi

t comment s on th e propose d change s to 31 0 CM R 7.0 0 o n behal f o f Dighto n Powe

r Associate s (DPA) , awholl y owne d subsidiar

y o f Calpin e Corporatio n (Calpine) . Th e DP A facilit y i n Dighto n Massachusett s i s anatura

l ga s fired combined cycl e powe r plan t generatin g anomina

l 17 0 megawatt

s o f electricit y fo r distributio n to th

e wholesal e powe

r market . I n general , w

e suppor t th e Department' s change s to th e rules , a s they clarif

y severa l definition s an

d incorporat

e recen t regulator y change s a t th e Federa l level . Ou

r commen t focuse s o n on

e issu e o f concer n relate d to th

e propose d chang e to th e continuou s emission s monitorin g syste m(CEMS ) requirements , a s describe d i n th e followin g paragraphs . Calpin e respectfull y urge s th

e Departmen

t to eithe r simplif y o r delet e th e proposed change s to Appendi x C (9)(c)(2 ) o f 31 0 CM R7.0

0 regarding th

e applicabilit

y o f Federa l performanc e an

d sitin g requirements fo r

CEMS . W

e believ e tha

t th e propose d changes to thi s section creat

e unnecessar

y confusio n ove

r applicable CEM S requirements , restrict s th e Department' s flexibility i n makin g decision s to resolve conflict s betwee n 4 0 CF R Par t 6 0 an d Par t 75 , an d provid e th

e potentia l fo r unwarranted changes t

o CEM S requirements a

t existin g permitte d facilities . Calpin e suggest s tha t th e Departmen

t kee p th e original language i n Appendi x C (9)(c)(2) , ad d areferenc e to 4

0 CF R Par t 75 , an d replace th e word s ".. . a

s applicable " t

o ".. . a s determined b y th

e Department, " o

r delet e Appendi x C(9)(c)(2 ) altogether . Eithe r o f ou r proposal s provide s th

e necessar

y linkag e t o th e tw o Federa

l CEM S requirements an

d retain s th

e Department' s flexibilit y to interpre t thes e requirement s an

d provide clea

r guidanc e t o permittee s regardin g their monitorin g obligations . Ou r specifi c concer

n wit h th e propose d change s t o Appendi x C (9)(c)(2 ) i s tha t i t applie s t o facilitie s i n whic h th

e Departmen

t ha s mad e aprio r determination t

o apply th e federa l regulation s ". . .independen t o f th e terms o f th e applicabl e requirements promulgate d o r approve d b y EPA. . .Suc

h determination s shall b

e mad e usin g apermi t

issuance , renewal , o r majo r modificatio n process... " Ther e i s nothin g i n th

e paragrap

h tha t protect s facilitie s currentl y holdin g vali d operating permit s fromhavin g t o repea t th e approva l an dpubli c commen t proces s durin g eac

h operating permi t

renewa l after th e proposed regulatio n i s promulgated . Facilitie s lik e DP A hav e mad e majo r investment s i n CEM S technolog y o n the basi s o f specifi c CEM S requirements establishe d i n operatin g permit s b y th e Department . Althoug h we believ e tha t i t i s reasonabl

e fo r th e Departmen

t t o revis e it s regulation s to incorporat e additiona

l Federa l requirements an

d suppor t th e specifi c inclusio n o f

Par t 7 5 CEM S requirements , w e d o no t believ e i t i s fai r t o expos e permittee s to potentia

l majo r operating o

r capita l expens e durin g eac

h permi t renewal . O n behal f o f Calpine , I woul d lik e t

o than k th e Departmen

t fo r th e opportunit

y to commen t o n th e propose d change s to 31 0 CM R7.00 . I f

yo u requir

e furthe r informatio n o r clarificatio n o f

ou r comment s please cal l m

e a t 617-557-5333 . Sincerely , Donal d Nea

l Safety , Healt

h an d Environmenta

l Manage r cc : Mat

t Palmer, DP

A Joh n Winkler , DE

P Southeas

t Regio n Ai r

Qualit y Sharo n Weber, DE

P Ai r Assessmen

t Branch