\1€° UNITED STATES ENVIRONMENTAL PROTECTION AGENCY______

REGION

IXFRO

75 Hawthorne Street San Francisco,
CA 94105-3901 FEB

0 6 2013 OFFJCEOFThE REGIONAL ADMINISTRATOR The Honorable Eddie Baza Calvo Ricardo

J. Bordallo Governor’s Complex Adelup, Guam 96910 Dear Governor Calvo: Thank you for your staff’s recommendations dated June
6, 2011 on air quality designations

for the territory
of Guam 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 2009-20

11 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/airquality/sulfurdioxide/irnplernent.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 Guam. Consequently,

the EPA
is not yet prepared

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

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

to our comprehensive implementation strategy.

In a separate future action or actions the EPA Printed
on Recycled Paperwillnotifyyouofourintendeddesignationsfortheseareas,andseekpubliccommentontheseactions,nolaterthan120dayspriortopromulgatinganyfinaldesignations.Welookforwardtoacontinueddialoguewithyouandyourstaffasweworktogethertoimplementthe2010primarySO2standard.ForadditionalinformationregardinginitialdesignationsoftheSO2standard,pleasevisitourwebsiteat:www.epa.gov/so2designations.Shouldyouhaveanyquestions,pleasedonothesitatetocallme,orhaveyourstaffcontactDeborahJordan,Director,AirDivisionat415-947-8715,orjordan.deborah(iepa.gov.Sincerely,fiJaredBlumenfeldcc:EricPalacios,Administrator,GuamEnvironmentalProtectionAgencyConchitaTaitano,Administrator,AirandLandDivision,GuamEnvironmentalProtectionAgencyPeterCruz,AirPollutionControlProgramManager,GuamEnvironmentalProtectionAgencyGinaMcCarthy,AssistantAdministratorforAirandRadiationStephenD.Page,Director,OfficeofAirQualityPlanningandStandards