UNITEDSTATESENVIRONMENTALPROTECTIONAGENCYREGION5-AUG1 92.014TheHonorableScottWalkerGovernorofWisconsin115EastCapitolMadison,Wisconsin53702DearGovernorWalker:77WESTJACKSONBOULEVARDCHICAGO,IL60604-3590REPLYTOTHEATTENTIONOFThankyouforyourrecommendationsdatedNovember25,2013,ofairqualitydesignationsforthe2012revisedprimaryammalfineparticle(PM2s)NationalAmbientAirQualityStandard(NAAQS)throughoutWisconsin.Iappreciatetheinforn1ationWisconsinsharedwiththeU.S.EnvironmentalProtectionAgencyaswemoveforwardtoimprovePM2.sairquality.ThisletteristonotifyyouofEPA'spreliminaryresponsetoWisconsin'srecommendationandtoinformyouofourapproachforcompletingtheinitialareadesignationsforthe2012revisedplimaryannualPM2.sstandard.OnDecember14,2012,EPApromulgatedarevisedprimaryannualPM2.sNAAQS(78FR3086,January15,2013).Inthataction,EPArevisedtheprimaryannualPM2.sstandard,strengtheningitfrom15.0microgramspercubicmeter()lg/m3)to12.0)lg/m3;retainedtheexisting24-hourPM2.sstandardat35)lg/m3;retainedtheexisting24-hourPM10(coarseparticle)standardat150)lglm3;andretainedthecurrentsuiteofsecondaryPMstandards.EPArevisedtheprimaryannualPM2.sstandardbasedonanintegratedassessmentofanextensivebodyofnewscientificevidence,whichsubstantiallystrengthensourbodyofknowledgeregardingPM2.5-relatedhealtheffects.TherevisedprimaryannualPM2.sstandardwillprovideincreasedprotectionforchildren,olderadults,personswithpre-existingheartandlungdisease,andotherat-riskpopulationsagainstanarrayofPM2.s-relatedadversehealtheffects,includingprematuremortality,increasedhospitaladmissionsandemergencydepartmentvisits,anddevelopmentandexacerbationofchronicrespiratorydisease.Historyshowsusthatbetterhealthandcleanerairgohand-in-handwitheconomicgrowth.Workingcloselywiththestatesandtribes,EPAisimplementingthestandardsusingacommonsenseapproachthatimprovesairqualityandminimizestheburdenonstate,local,andtribalgovernments.Aspartofthisprocess,EPAisworkingwiththestatesandtribestoidentifyareasinthecountrythatmeetthestandardsandthosethatneedtotakestepstoreducePM2.5airpollution.Withinoneyearofpromulgationofaneworrevisedairqualitystandard,theCleanAirActrequirestheGovernorofeachstatetosubmittoEPAalistofallareasinthestate,withadesignationrecommendationforeacharea.Asafirststepinimplementingthe2012annualPM2.sstandard,Governorsweretosubmittheirdesignationrecommendations,includingappropriateareaboundaries,byDecember13,2013.Recycled/Recyclable•PrintedwithVegetableOilBasedInkson100%RecycledPaper(100%Post-Consumer)

# As required

by the Clean

Air Act, EPA then promulgates

de

s ignation

s for all areas across

the country.

EPA designates

an area

as

" nonattainment

" if
it is violating

the 20

1 2 annual
PM2

. s NAAQS

or if
it is contributing

to

a vio

l ation

of the NAAQS

in

a nearb

y area. Cons

i ste nt w ith de

s ignati

o n s for previous

PM

2.s standards

, EPA intends

to use

a designation category

of "unc

l assifiable/attainm

ent

" for areas that are monitoring attainment

or do not have monitors,

but for which EPA has reason

to believe

are likely attainment

and are not contributing

to nearby violations. Additionally,

EPA intends

to designate

as

" unclassifiable

" those areas where EPA cannot determine
based

on available information whether

the area

is meeting

the NAAQS

or where EPA
has not determined

that the area contributes

to

a nearby violation.

At this time, EPA is proceeding

with initial area designations

u sing quality-assured,

certified

air quality monitoring data from 2011

to 2013. EPA has reviewed Wisconsin's November

25

, 2013, annual PM2.s designation recommendations and other relevant technical information, including 2011-2013

ai

r quality
data. These data

do not indicate

any vio

l ation

of th

e 20

1 2 annual
PM2

. s NAAQS

in Wisconsin

o r contribution

to any nearb

y area. Accordingly,

EPA intend

s to

d es

i g n ate the entire state

of Wisconsin

as uncla

ss ifiable

/a ttainment. EPA will make

its proposed designation decisions

and supporting documentation

ava ilabl

e to the genera

l public

for review

and comment.

We will

be announcing

a 30-day public comme

nt period shortly

in the 

# Federal Register.

After considering

any additional information

we

r ece ive

, EPA plans

to promulgate

final annual PM2.s designations

in December of2014. EPA

is committed

to working

with
the states
and tribes

to

s hare
the

r esponsibi

lit
y of reducing PM2.

s air pollution. Current

and upcoming federal standards

and safeguards

- including pollution reduction

rules

for power plants

, vehicles

, and fuels-

will ensure steady progress

to reduce
PM2

.s -forming

po

ll ution
and will protect public health

in communiti

e s across

th

e country. We look forward

to

a continued dialogue

w

i th yo

u and your staff

as we wo rk together

to impl ement

the 2012 annual

PM

2

. s standard.

If you any question

s

, please contact

me
or your staff may contact Ronna Beckmann

or

E il een Deamer

, the Region

5 Intergovernmental

Liaisons, at (312) 886-3000

. Sincerely, Susan Hedman Regional Administrator cc:

Cathy Stepp Secretary, Wisconsin Department ofNatural Resources Pat Stevens Admini

s t r ator

, Divi

s ion of Air and Waste Wisconsin Department ofNatura

l Resources