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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
 

REGION 8
 

1595 Wynkoop Street 

DENVER, CO 80202-1129 

Phone 800-227-8917 

http://www,epa,gov/region08 

Ref: 8P-AR 

The Honorable John Hickenlooper 

Governor of Colorado 

State Capitol 

Denver, Colorado 80203 

Dear Governor Hickenlooper: 

On June 3, 20 I0, the U.S. Environmental Protection Agency (EPA) revised the healthbased National Ambient Air Quality Standard (NAAQS) for sulfur dioxide (S02) by establishing 

a new I-hour standard at a level of75 parts per billion (ppb). This new I-hour standard will 

protect public health by reducing people's exposure to high short-term (5-minutes to 24-hours) 

concentrations of S02. An area meets the new standard when the 3-year average ofthe 99th 

percentile of I-hour daily maximum concentrations does not exceed 75 ppb. 

Within one year of establishing a new or revised standard, each governor must 

recommend a designation of attainment, nonattainment or unclassifiable, with appropriate 

boundaries, for areas within their jurisdiction. Therefore, we ask that your State provide 

designation recommendations, including appropriate area boundaries, for all areas by 

June 3, 2011, with respect to the I-hour S02 NAAQS. Section 107(d)(1) of the Clean Air Act 

(CAA) describes the process EPA follows for designating areas as meeting or no.t meeting a new 

or revised NAAQS. 

The CAA requires that we complete designations by no later than June 3, 2012. We plan 

to announce our intended designations no later than 120 days prior to promulgating final 

designations. Following the announcement of intended designations, states and tribes will have 

the opportunity to comment on any modifications EPA proposes to their recommendations. The 

enclosed memorandum provides guidance to state and local air pollution control agencies and 

tribes on the timeline and process for designating areas under the revised S02 standard. 
Establishing area designations is a key step in the process of providing the health 

protection intended by the CAA. Should you have questions regarding this matter, please do not 

hesitate to contact me or your staff may contact Monica Morales, of my staff, at (303) 312-6936. 

Sincerely, 

James B. Martin 

Regional Administrator 

Enclosure 

cc:	 Martha Rudolph, Executive Director, CDPHE 

Paul Tourangeau, Director, APCD 

2
 
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION 8 

1595 Wynkoop Street 

DENVER, CO 80202-1129 

Phone 800-227-8917 

http://www.epa.gov/region08 

Ref: 8P-AR 

The Honorable Brian Schweitzer 

Governor of Montana 

State Capitol 

Helena, Montana 59620-0801 

Dear Governor Schweitzer: 

On June 3. 2010, the U.S. Environmental Protection Agency (EPA) revised the heathbased National Ambient Air Quality Standard (NAAQS) for sulfur dioxide (S02) by establishing 

a new I-hour standard at a level of 75 parts per billion (ppb). This new I-hour standard will 

protect public health by reducing people's exposure to high short-term (5-minutes to 24-hours) 

concentrations of S02. An area meets the new standard when the 3-year average ofthe 99th 

percentile of I-hour daily maximum concentrations does not exceed 75 ppb. 

Within one year of establishing a new or revised standard, each governor must 

recommend a designation of attainment, nonattainment or unclassifiable, with appropriate 

boundaries, for areas within their jurisdiction. Therefore, we ask that your State provide 

designation recommendations, including appropriate area boundaries, for all areas by 

June 3, 2011, with respect to the I-hour S02 NAAQS. Section I07(d)(l) of the Clean Air Act 

(CAA) describes the process EPA follows for designating areas as meeting or not meeting a new 

or revised NAAQS. 

The CAA requires that we complete designations by no later than June 3, 2012. We plan 

to announce our intended designations no later than 120 days prior to promulgating final 

designations. Following the announcement of intended designations, states and tribes will have 

the opportunity to comment on any modifications EPA proposes to their recommendations. The 

enclosed memorandum provides guidance to state and local air pollution control agencies and 

tribes on the timeline and process for designating areas under the revised S02 standard. 
Establishing area designations is a key step in the process of providing the health 

protection intended by the CAA. Should you have questions regarding this matter, please do not 

hesitate to contact me or your staff may contact Monica Morales, of my staff, at (303) 312-6936. 

Sincerely, 

/!~::!ti7# Regional Administrator 

Enclosure 

cc:	 Richard Opper, Director, DEQ 

Dave Klemp, Bureau Chief, ARMB 

2
 
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION 8 

1595 Wynkoop Street 

DENVER, CO 80202-1129 

Phone 800-227-8917 

http://www.epa. gov/region08 

Ref: 8P-AR 

The Honorable Jack Dalrymple 

Governor of North Dakota 

State Capitol 

Bismarck, North Dakota 58505 

Dear Governor Dalrymple: 

On June 3, 2010, the U.S. Environmental Protection Agency (EPA) revised the heathbased National Ambient Air Quality Standard (NAAQS) for sulfur dioxide (S02) by establishing 

a new I-hour standard at a level of 75 parts per billion (ppb). This new I-hour standard will 

protect public health by reducing people's exposure to high short-term (5-minutes to 24-hours) 

concentrations ofS02. An area meets the new standard when the 3-year average ofthe 99th 

percentile of I-hour daily maximum concentrations does not exceed 75 ppb. 

Within one year of establishing a new or revised standard, each governor must 

recommend a designation of attainment, nonattainment or unclassifiable, with appropriate 

boundaries, for areas within their jurisdiction. Therefore, we ask that your State provide 

designation recommendations, including appropriate area boundaries, for all areas by 

June 3, 2011, with respect to the I-hour S02 NAAQS. Section I07(d)(1) ofthe Clean Air Act 

(CAA) describes the process EPA follows for designating areas as meeting or not meeting a new 

or revised NAAQS. 

The CAA requires that we complete designations by no later than June 3, 2012. We plan 

to announce our intended designations no later than 120 days prior to promulgating final 

desigriations. Following the announcement of intended designations, states and tribes will have 

the opportunity to comment on any modifications EPA proposes to their recommendations. The 

enclosed memorandum provides guidance to state and local air pollution control agencies and 

tribes on the timeline and process for designating areas under the. revised S02 standard. 
Establishing area designations is a key step in the process of providing the health 

protection intended by the CAA. Should you have questions regarding this matter, please do not 

hesitate to contact me or your staff may contact Monica Morales, of my staff, at (303) 312-6936. 

Sincerely, 

James 4~' B. Martin 

Regional Adminis ratol' 

Enclosure 

cc:	 David Glatt, Section Chief, NDDH 

Terry O'Clair, Director, NDDH 

2
 
UNrrED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION 8 

1595 Wynkoop Street 

DENVER, CO 80202-1129 

Phone 800-227-8917 

http://www.epa.gov/region08 

Ref: 8P-AR· 

The Honorable Dennis Daugaard 

Governor of South Dakota 

State Capitol 

Pierre, South Dakota 5750 I 

Dear Governor Daugaard: 

On June 3,2010, the U.S. Environmental Protection Agency (EPA) revised the heathbased National Ambient Air Quality Standard (NAAQS) for sulfur dioxide (S02) by establishing 

a new I-hour standard at a level of 75 parts per billion (ppb). This new I-hour standard will 

protect public health by reducing people's exposure to high short-term (5-minutes to 24-hours) 

concentrations of S02. An area meets the new standard when the 3-year average ofthe 99th 

percentile of I-hour daily maximum concentrations does not exceed 75 ppb. 

Within one year of establishing a new or revised standard, each governor must 

recommend a designation of attainment, nonattainment or unclassifiable, with appropriate 

boundaries, for areas within their jurisdiction. Therefore, we ask that your State provide 

designation recommendations, including appropriate area boundaries, for all areas by 

June 3,2011, with respect to the I-hour S02 NAAQS. Section 107(d)(1) of the Clean Air Act 

(CAA) describes the process EPA follows for designating areas as meeting or not meeting a new 

or revised NAAQS. 

The CAA requires that we complete designations by no later than June 3, 2012. We plan 

to announce our intended designations no later than 120 days prior to promulgating final 

designations. Following the announcement of intended designations, states and tribes will have 

the opportunity to comment on any modifications EPA proposes to their recommendations. The 

enclosed memorandum provides guidance to state and local air pollution control agencies and 

tribes on the timeline and process for designating areas under the revised S02 standard. 
Establishing area designations is a key step in the process of providing the health 

protection intended by the CAA. Should you have questions regarding this matter, please do not 

hesitate to contact me or your staff may contact Monica Morales, of my stafl~ at (303) 312-6936. 

Sincerely, 

L-t~ James B. Mart~ Regional Administrator 

Enclosure 

cc:	 Steven M. Pimer, P.E. Secretary, DENR 

Brian Gustafson, Administrator, AQP 

2
 
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION 8 

1595 Wynkoop Street 

DENVER, CO 80202-1129 

Phone 800-227-8917 

http://W'NW.epa.gov/region08 

Ud) 24 2011 

Ref: 8P-AR 

The Honorable Gary R. Herbert 

Governor of Utah 

State Capitol 

Salt Lake City, Utah 84114 

Dear Governor Herbert: 

On June 3, 2010, the U.S. Environmental Protection Agency (EPA) revised the heathbased National Ambient Air Quality Standard (NAAQS) for sulfur dioxide (SOl) by establishing 

a new I-hour standard at a level of75 parts per billion (ppb). This new I-hour standard will 

protect public health by reducing people's exposure to high short-term (5-minutes to 24-hours) 

concentrations of SOl. An area meets the new standard when the 3-year average of the 99th 

percentile of I-hour daily maximum concentrations does not exceed 75 ppb. 

Within one year of establishing a new or revised standard, each governor must 

recommend a designation of attainment, nonattainment or unclassifiable, with appropriate 

boundaries, for areas within their jurisdiction. Therefore, we ask that your State provide 

designation recommendations, including appropriate area boundaries, for all areas by 

June 3, 2011, with respect to the I-hour SOl NAAQS. Section 107(d)(l) of the Clean Air Act 

(CAA) describes the process EPA follows for designating areas as meeting or not meeting a new 

or revised NAAQS. 

The CAA requires that we complete designations by no later than June 3, 2012. We plan 

to announce our intended designations no later than 120 days prior to promulgating final 

designations. Following the announcement of intended designations, states and tribes will have 

the opportunity to comment on any modifications EPA proposes to their recommendations. The 

enclosed memorandum provides guidance to state and local air pollution control agencies and 

tribes on the timeline and process for designating areas under the revised S02 standard. 
Establishing area designations is a key step in the process of providing the health 

protection intended by the CAA. Should you have questions regarding this matter, please do not 

hesitate to contact me or your staff may contact Monica Morales, of my staff, at (303) 312-6936. 

Sincerely, 

James B. Martin 

Regional Administ 

Enclosure 

cc:	 Amanda Smith, Executive Director, UDEQ 

Cheryl Heying, Director, DAQ 

2
 
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION 8 

1595 Wynkoop Street 

DENVER, CO 80202-1129 

Phone 800-227-8917 

http://www.epa.gov/region08 

Ref: 8P-AR 

The Honorable Matt Mead 

Governor of Wyoming 

State Capitol 

Cheyenne, Wyoming 82002 

Dear Governor Mead: 

On June 3, 2010, the U.S. Environmental Protection Agency (EPA) revised the heathbased National Ambient Air Quality Standard (NAAQS) for sulfur dioxide (S02) by establishing 

a new I-hour standard at a level of 75 parts per billion (ppb). This new I-hour standard will 

protect public health by reducing people's exposure to high short-term (5-minutes to 24-hours) 

concentrations of S02. An area meets the new standard when the 3-year average ofthe 99th 

percentile of I-hour daily maximum concentrations does not exceed 75 ppb. 

Within one year of establishing a new or revised standard, each governor must 

recommend a designation of attainment, nonattainment or uncIassifiable, with appropriate 

boundaries, for areas within their jurisdiction. Therefore, we ask that your State provide 

designation recommendations, including appropriate area boundaries, for all areas by 

June 3,2011, with respect to the I-hour S02 NAAQS. Section 107(d)(l) ofthe Clean Air Act 

(CAA) describes the process EPA follows for designating areas as meeting or not meeting a new 

or revised NAAQS. 

The CAA requires that we complete designations by no later than June 3, 2012. We plan 

to announce our intended designations no later than 120 days prior to promulgating final 

designations. Following the announcement of intended designations, states and tribes will have 

the opportunity to comment on any modifications EPA proposes to their recommendations. The 

enclosed memorandum provides guidance to state and local air pollution control agencies and 

tribes on the timeline and process for designating areas under the revised S02 standard. 
Establishing area designations is a key step in the process of providing the health 

protection intended by the CAA. Should you have questions regarding this matter, please do not 

hesitate to contact me or your staff may contact Monica Morales, of my staff, at (303) 312-6936. 

Sincerely, 

James ~.~ B. Martin 

Regional Administra or 

Enclosure 

cc:	 John Corra, Director, DEQ 

Steven A. Dietrich, Administrator, AQD 

2