DS?41. UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION

IXPRO1

75 Hawthorne Street San Francisco,

CA 94105-3901 rEnOFFICEOFTHE T D U U £013REGIONALADMINISTRATOR The Honorable Edmund

G. Brown State Capitol Building, Suite #1173 Sacramento, California 95814 Dear Governor Brown: Thank you for your staffs recommendations
dated June 20, 2011 on air quality designations

for the state of California
for the 2010 revision

to the primary National Ambient Air Quality Standard
for sulfur dioxide (SO 2 ). Reducing levels of SO 2 pollution

is an important part of the U. S. Environmental Protection Agency’s (EPA) commitment

to a clean, healthy environment. Exposure

to SO 2 can cause

a range of adverse health effects, including narrowing

of the airways which can cause difficulty breathing and increased asthma symptoms. This letter

is to notify you of the EPA’s preliminary intentions regarding your recommended designations. On June
3, 2010, the EPA strengthened

the health-based

or “primary” standard
for SO 2 by establishing

a standard
for 1-hour average SO 2 concentrations

at a level of 75 parts per billion. The Clean Air Act requires the EPA to complete
the initial designations process within two years of promulgating

a new or revised standard.

If the Administrator

has insufficient information

to make these designations,

the EPA has the authority

to extend the designation process
by up to one year. On July 27, 2012, the EPA announced that
it had insufficient information

to complete
the designations

for the 1-hour SO 2 standard within two years and extended
the designations deadline

to June
3, 2013. At this time the EPA

is proceeding with designating

as nonattainment
most areas
in locations where existing monitoring data from 2009-2011 indicate violations

of the 1-hour SO 2 standard. The EPA intends

to address the designations

for all other areas
in separate future actions. With input from

a diverse group of stakeholders, EPA has developed

a comprehensive implementation strategy for these future actions that focuses resources

on identifying
and addressing unhealthy levels of SO 2 . The strategy

is available

at: www.epa.gov/airguality/sulfurdioxide/implernent.html.

The EPA will continue to work closely with you and our other partners

at the state, tribal and local levels
to ensure healthprotective, common sense implementation

of the 1-hour SO 2 standard. The EPA’s review
of the most recent monitored

air quality data from 2009-2011 shows no violations

of the 2010 SO 2 standard

in any areas
in California. Consequently,

the EPA
is not yet prepared

to propose designation action
in California
and is therefore currently deferring action
to designate areas
in California. The EPA expects

to be able to proceed with designation action
in California once additional data are gathered pursuant

to our comprehensive implementation strategy.

In a separate future action
or Printed
on Recycled PaperactionstheEPAwillnotifryouofourintendeddesignationsfortheseareas,andseekpubliccommentontheseactions,nolaterthan120dayspriortopromulgatinganyfinaldesignations.Welookforwardtoacontinueddialoguewithyouandyourstaffasweworktogethertoimplementthe2010primarySO2standard.ForadditionalinformationregardinginitialdesignationsoftheSO2standard,pleasevisitourwebsiteat:www.epa.gov/so2designations.Shouldyouhaveanyquestions,pleasedonothesitatetocallme,orhaveyourstaffcontactDeborahJordan,Director,AirDivisionat415-947-8715,orjordan.deborah@epa.gov.Sincerely,tfr1_JadBlumenfeldcc:MatthewRodriguez,Secretary,CaliforniaEnvironmentalProtectionAgencyMaryNichols,Chairman,CaliforniaAirResourcesBoardJamesGoldstene,ExecutiveOfficer,CaliforniaAirResourcesBoardLynnTerry,DeputyExecutiveOfficer,CaliforniaAirResourcesBoardKarenMagliano,Chief,AirQualityDataBranch,PlanningandTechnicalSupportDivision,CaliforniaAirResourcesBoardKennethKoyama,ExecutiveDirector,CaliforniaAirPollutionControlOfficersAssociationGinaMcCarthy,AssistantAdministratorforAirandRadiationStephenD.Page,Director,OfficeofAirQualityPlanningandStandards