UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595 Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://wvvw.epa.gov/region08

". Ref: 8P-AR The Honorable A. T. "Rusty" Stafne, Chairman Assiniboine & Sioux Tribes POBox 1027 Poplar,MT 59255-1027 Dear Chairman Stafne: The purpose ofthis letter is to provide you with information and guidance on the U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (S02) National Ambient Air Quality Standard (NAAQS). Your Tribes may find it important to engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offer you consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised S02 standard. OnJune 3, 2010, EPA added a new primary NAAQS for S02 in orderto provide increased protection ofpublic health from S02pollution. The new standard of75 parts per billion (ppb), is attained when the 3-year average ofthe 99th percentile ofI-hour daily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary

.standard. In this action EPA is only designating for the new, I-hour 75 ppb S02 standard. Establishing area designations is a key step in the process ofprovidingthe health protection intended by the Clean Air Act (CAA). Within two years ofpromulgation ofa new or revised NAAQS, section 107(d)(l)(A)ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areasthat meet the standard; Nonattainment-areasthat either do not meet the standard, or are contributing to a nearby area that does not meet the standard; or Unclassifiable-areas where there is insufficient informationto make a determination. These designations are based on current air quality information, recommendations from State Governors and Tribal Leaders, and otherrelevant information discussed in the enclosed guidance document. We request and encourage your recommendation for designation ofyour area for consideration in this process.While tribes are not obligated to participate inthe designations process, we invite and encourage you to do so. Please notify us ifyou are interested participating in the designations process and/or receiving consultation regarding the process. Ifyouchoose to participate, we ask that you provide yourdesignations recommendation to EPA by June 3, 2011. We are required to issue final designations by no laterthan June 3, 2012. We plan to announce our intended designations as early as possible after receipt ofrecommendations, but no later than 120 days prior to promulgating the final designations. Following the announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may propose to a tribe's original recommendation. The enclosed memorandum provides guidance on the process for designating areas under the new S02NAAQS. Ourdesignations will be based on the most recent three calendar years of certified, quality-assured monitoring data available, and any otherrelevant information that is provided, including refined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance or other support activities. We look forward to working with you and your staffto develop area designations under the new S02 standard in a timely manner. IfyourTribes are interested in consultation or participating in further discussions or meetings with EPA officials about the designations process, please do not hesitate to contact me oryour staffmay contact Alfreda Mitre, at (303) 312-6343 orMonica Morales, at (303) 312-6936.
Sincerely,

James B. Marti Regional Admin

Enclosure Cc: DebMadison, Environmental DirectorUNITED 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 Willie A. Sharp, Chairman BlackfeetTribe POBox 850 Browning, MT 59417-2029 Dear Chairman Sharp: The purpose ofthis letter is to provide you with information and guidance on the U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (SOl) National Ambient Air Quality Standard (NAAQS). Your Tribe may find it important to engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offeryou consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised SOl standard. On June 3, 2010, EPA added a new primary NAAQS for SOl in orderto provide increased protection ofpublic health from SOlpollution. The new standard of75 partsper billion (ppb), is attained when the 3-yearaverage ofthe 99th percentile ofI-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. In this action EPA is only designating for the new, I-hour 75 ppb S02 standard. Establishing area designations is a key step in the process ofproviding the health protection intended by the Clean AirAct (CAA). Within two years ofpromulgation ofa new or revised NAAQS, section 107(d)(1)(A) oftheCAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areasthat meet the standard; Nonattainment-areasthat eitherdo not meet the standard, or are contributing to a nearby area that does not meet the standard; or Unclassifiable-areaswhere there is insufficient information to make a determination. These designations are based on current airquality information, recommendations from State Governors and Tribal Leaders, and otherrelevant information discussed in the enclosed guidance document. We request and encourage your recommendation for designation ofyour area for consideration in this process.While tribes are not obligatedto participate in the designations process, we invite and encourage youto do so. Please notify us ifyou are interested participating in the designations process and/or receiving consultationregarding the process. Ifyou choose to participate, we ask that you provide your designations recommendation to EPA by June 3, 2011. We are required to issue final designations by no later than June 3,2012. We planto announce our intended designations as early as possible after receipt ofrecommendations,but no later than 120 days prior to promulgatingthe final designations. Following the announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may propose to a tribe's original recommendation. The enclosed memorandum provides guidance on the process for designating areas under the new S02NAAQS. Our designations will be based on the most recent three calendar years of certified, quality-assured monitoring data available, and any other relevant infonnationthat is provided, includingrefined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance or other support activities. We look forward to working with you and your staffto develop area designations under the new S02 standard in a timely manner. Ifyour Tribe is interested in consultation or participating in further discussions or meetings with EPA officials about the designations process, please do not hesitate to contact me oryour staffmay contact Alfreda Mitre, at (303) 312-6343 or MonicaMorales, at (303) 312-6936.
Sincerely,

James B. Martin Regional Administrator

Enclosure Cc: Gerald Wagner, Environmental DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08

Ref: 8P-AR The Honorable Kevin C. Keckler, Chairman Cheyenne River Sioux Tribe POBox 590 Eagle Butte, SD 57625-0590 Dear Chairman Keckler: The purpose ofthis letter is to provide you with information and guidance onthe U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (SOz) National Ambient Air Quality Standard (NAAQS). Your Tribe may find it important to engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offeryou consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised SOz standard. OnJune 3, 20I0, EPA added a new primary NAAQS for SOz in orderto provide increased protection ofpublic health from SOzpollution. The new standard of75 parts per billion (ppb), is attained when the 3-yearaverage ofthe 99th percentile ofI-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. In this action EPA is only designating for the new, I-hour 75 ppb SOz standard. Establishing areadesignations is a key step in the process ofprovidingthe health protection intended by the CleanAirAct (CAA). Within two years ofpromulgation ofa new or revised NAAQS, section 107(d)(l)(A) ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areasthat meet the standard; Nonattainment-areas that either do not meet the standard, orare contributing to a nearby areathat does not meet the standard; or Unclassifiable-areaswhere there is insufficient information to make a determination. These designations are based on current air quality information, recommendations from State Governors andTribal Leaders, and other relevant information discussed in the enclosed guidance document. We request and encourage your recommendation for designation ofyour area for consideration in this process.While tribes are not obligated to participate in the designations process, we invite and encourage youto do so. Please notify us ifyou are interested participating in the designations process and/or receiving consultation regarding the process. Ifyou choose to participate, we ask that you provide your designationsrecommendation to EPA by June 3, 2011. We are required to issue final designations by no laterthan June 3, 2012. We plan to announce our intended designations as early as possible after receipt ofrecommendations, but no later than 120 days prior to promulgating the final designations. Followingthe announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may propose to a tribe's original recommendation. The enclosed memorandum provides guidance onthe process for designating areas under the new S02NAAQS. Our designations will be based onthe most recent three calendaryears of certified, quality-assured monitoring data available, and any other relevant informationthat is provided, includingrefined air quality dispersion modeling. As the process moves forward, we will keep you andyour statTinformed ofany additional guidance orother support activities. We look forward to working with you and your staffto develop area designations under the new S02 standard in a timely manner. Ifyour Tribe is interestedinconsultation orparticipating in further discussions ormeetings with EPA officials about the designations process, please do not hesitate to contact me or your staffmay contact AlfredaMitre, at (303) 312-6343 or MonicaMorales, at (303) 312-6936.
Sincerely,

# J~~ Regional Administrator

Enclosure Cc: David D. Nelson, Environmental DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08

Ref: 8P-AR The Honorable Raymond Parker, Chairman Chippewa-Cree Tribe POBox 544 Rocky Boy Route Box Elder, MT 59521-0544 Dear Chairman Parker: The purpose ofthis letter is to provide you with information and guidance onthe U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (S02) National Ambient Air Quality Standard (NAAQS). Your Tribe may find it important to engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offer you consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised S02 standard. On June 3, 2010, EPA added a new primaryNAAQS for S02 in orderto provide increased protection ofpublic health from S02pollution. The new standard of75 parts per billion (ppb), is attained when the 3-year average ofthe 99th percentile of 1-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. In this action EPA is only designating for the new, 1-hour 75 ppb S02 standard. Establishing areadesignations is a key step in the process ofprovidingthe health protection intended by the Clean Air Act (CAA). Within two years ofpromulgation ofanew or revisedNAAQS, section 107(d)(1)(A) ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areas that meet the standard; Nonattainment-areasthat either do not meet the standard, or are contributing to a nearby areathat does not meet the standard; or Unclassifiable-areas where there is insufficient informationto make a determination. These designations are based on current air quality information, recommendations from State Governors and Tribal Leaders, and other relevant information discussed in the enclosed guidance document. We request and encourage your recommendation for designation ofyour area for consideration in this process. .While tribes are not obligated to participate in the designations process, we invite and encourage you to do so. Please notify us ifyou are interested participating in the designations process and/or receiving consultation regarding the process. Ifyou choose to participate, we ask that youprovide your designations recommendation to EPA by June 3, 2011. We are required to issue final designations by no later than June 3, 2012. We plan to announce our intended designations as early as possible after receipt ofrecommendations, but no later than 120 days priorto promulgating the final designations. Following the announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may propose to a tribe's original recommendation. The enclosed memorandum provides guidance onthe process for designating areas under the new S02NAAQS. Our designations will be based on the mostrecentthree calendar years of certified, quality-assured monitoring data available, and any other relevant information that is provided, including refined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance or other support activities. We look forward to working with you and your staffto develop area designations under the new S02 standard in a timely manner. Ifyour Tribe is interested in consultation or participating in further discussions or meetings with EPA officials about the designations process, please do not hesitate to contact me or your staffmay contact Alfreda Mitre, at (303) 312-6343 or Monica Morales, at (303) 312-6936.
Sincerely,

James B. Martin· ...nv,"--­ Regional Adminis rator

Enclosure Cc: Jonathan Jay Eagleman, Environmental DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08



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Ref: 8P-AR The Honorable E.T. "Bud" Moran, Chairman Confederated Salish & Kootenai Tribes POBox 278 Polson, MT 59860-0278 Dear Chairman Moran: Thepurpose ofthis letter is to provide you with information and guidance on the U.S. Environmental Protection Agency's (EPA) designations processfor the revised sulfur dioxide (SOz) National Ambient Air Quality Standard (NAAQS). Your Tribes may find it importantto engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process andto offeryou consultation. We wantto ensure early, transparent and effective communication in proposing area designations for the revised SOz standard. On June 3, 2010, EPA added a new primary NAAQS for SOz in order to provide increased protection ofpublic health from SOz pollution. The new standard of75 parts per billion (ppb), is attained when the 3-year average ofthe 99th percentile ofI-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. In this action EPA is only designating for the new, I-hour 75 ppb SOz standard. Establishing area designations is akey step in the process ofprovidingthe health protection intended by the Clean AirAct (CAA). Within two years ofpromulgation ofa newor revised NAAQS, section 107(d)(l)(A) ofthe CAArequires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areasthat meet the standard; Nonattainment-areasthat eitherdo not meet the standard, orare contributingto a nearby area that does not meetthe standard; or Unclassitiable-areas where there is insufficient information to make a determination. These designations are based on current airquality information, recommendations from State Governors and Tribal Leaders, and otherrelevant information discussed in the enclosed guidance document. We request and encourage yourrecommendation for designation ofyour area for consideration in this process.While tribes are not obligated to participate in the designations process, we invite and encourage you to do so. Please notify us ifyou are interested participating in the designations process and/or receiving consultation regarding the process. Ifyou choose to participate, we ask that you provide your designations recommendationto EPA by June 3, 2011. We are required to issue final designations by no laterthan June 3, 2012. We plan to announce our intended designations as early as possible after receipt ofrecommendations, but no later than 120 days prior to promulgating the final designations. Followingthe announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may propose to a tribe's original recommendation. The enclosed memorandum provides guidance on the process for designating areas under the new S02NAAQS. Our designations will be based on the mostrecent three calendar years of certified, quality-assured monitoring data available, and any otherrelevant information that is provided, including refined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance or other support activities. We look forward to working with you and your staffto develop area designations under the new S02 standard in a timely manner. Ifyour Tribes are interested in consultation or participating in further discussions or meetings with EPA officials about the designations process, please do not hesitate to contact me or your staffmay contact Alfreda Mitre, at (303) 312-6343 orMonica Morales, at (303) 312-6936.
Sincerely,

James B. Martin Regional Administrator

Enclosure Cc: Mike Durglo, Environmental DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08

Ref: 8P-AR The Honorable Duane Big Eagle, Chairman CrowCreek Sioux Tribe P

# a Box 50 Fort Thompson, SO 57339-0380 Dear Chairman Big Eagle: The purpose ofthis letter is to provide you with information and guidance on the U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (S02) National Ambient Air Quality Standard (NAAQS). Your Tribe may find it important to engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offer you consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised S02 standard. OnJune 3. 2010, EPA added a newprimary NAAQS for S02 in order to provide increased protection ofpublic health from S02pollution. The new standard of75 parts per billion (ppb). is attained when the 3-year average ofthe 99th percentile ofI-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. 

### In this action EPA is only designating for the new, I-hour 75 ppb S02 standard. Establishing area designations is a key step in the process ofprovidingthe health protection intended by the Clean Air Act (CAA). Within two years ofpromulgation ofa new or revised NAAQS, section 107(d)(1)(A) ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areasthat meet the standard; Nonattalnment-areasthat either do not meet the standard, or are contributing to a nearby area that does not meet the standard; or Unclassifiable-areaswhere there is insufficient information to make a determination. These designations are based on current air quality information, recommendations from State Governors and Tribal Leaders, and other relevant information discussed in the enclosed guidance document. We request and encourage yourrecommendation for designation ofyour area for consideration in this process.While tribes are not obligated to participate in the designations process, we invite and encourage you to do so. Please notify us ifyou are interested participating in the designations process and/or receiving consultation regarding the process. Ifyou choose to participate, we ask that you provide your designations recommendation to EPA by June 3, 2011. We are required to issue final designations by no later than June 3,2012. We plan to announce our intended designations as earlyas possible after receipt ofrecommendations, but no laterthan 120 days prior to promulgating the final designations. Followingthe announcement of intended designations, tribes will have an additional opportunityto consult on any modifications EPA may propose to a tribe's original recommendation. The enclosed memorandum provides guidance on the process for designating areas under the new S02NAAQS. Our designations will be based onthe most recent three calendaryears of certified, quality-assured monitoring data available, and any other relevant informationthat is provided, including refined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance or other support activities. We lookforward to working with you and your staffto develop areadesignations underthe new S02 standard in a timely manner. IfyourTribe is interested in consultation or participating in further discussions ormeetings with EPA officials about the designations process, please do not hesitate to contactme oryour staffmay contact Alfreda Mitre, at (303) 312-6343 orMonicaMorales, at (303) 312-6936.
Sincerely,

James B. Marti Regional Adminis rator

# ~~

Enclosure Cc: Marie Charger, Environmental DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08 l;' ,. 1"", n LLi**':.~** \. ",..; .;;. i , Ref: 8P-AR The Honorable Cedric Black Eagle, Chainnan Crow Tribe POBox400 Crow Agency, MT 59022-0400 Dear Chairman Black Eagle: The purpose ofthis letter is to provide you with infonnation and guidance on the U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (S02) National Ambient Air Quality Standard (NAAQS). YourTribe may find it important to engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offeryou consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised S02 standard. On June 3, 2010, EPA added a new primary NAAQS for S02 in order to provide increased protection ofpublic health from S02pollution. The new standard of75 parts per billion (ppb), is attained whenthe 3-yearaverage ofthe 99th percentile ofI-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. In this action EPA is only designating for the new, I-hour 75 ppb S02 standard. Establishing area designations is a key step in the process ofprovidingthe health protection intended by the Clean Air Act (CAA). Within two years ofpromulgation ofa new or revised NAAQS, section I07(d)(l)(A) ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areasthat meet the standard; Nonattainment-areasthat eitherdo not meet the standard, or are contributingto a nearby area that does not meet the standard; or Unclassifiable-areaswhere there is insufficient infonnation to make a detennination. These designations are based on current air quality infonnation, recommendations from State Governors and Tribal Leaders. and otherrelevant information discussed in the enclosed guidance document. We request and encourage your recommendation for designation ofyour area for consideration in this process.While tribes are not obligated to participate in the designations process, we invite and encourage you to do so. Please notify us ifyou are interested participating in the designations process and/orreceiving consultation regarding the process. Ifyou choose to participate, we ask that you provide your designations recommendationto EPAby June 3, 2011. We are required to issue final designations by no later than June 3, 2012. We planto announce our intended designations as early as possible after receipt ofrecommendations, but no later than 120 days priorto promulgatingthe final designations. Following the announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may propose to a tribe's original recommendation. The enclosedmemorandumprovides guidance on the process for designating areas under the new S02NAAQS. Our designations will bebased onthe most recent three calendaryears of certified, quality-assured monitoring data available, and any other relevant informationthat is provided, including refined air quality dispersion modeling. Asthe process moves forward, we will keep you and your staffinformed ofany additional guidance or other support activities. We look forward to working with you and your staffto develop areadesignations underthe new S02 standard in a timely manner. Ifyour Tribe is interested in consultation orparticipating in further discussions ormeetings with EPAofficials about the designations process, please do not hesitate to contactme or your staffmay contact AlfredaMitre, at (303) 312-6343 orMonicaMorales, at (303) 312-6936.
Sincerely,

# J~~ Regional Administrator

Enclosure Cc: Myron 1. Shield Jr., Environmental DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08

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..**~,,;** < Ref: 8P-AR The Honorable Mike Lajeunesse, Chairman Eastern Shoshone Tribe POBox 538 Fort Washakie. WY 82514-0217 Dear Chairman Lajeunesse: The purpose ofthis letter is to provide you with information and guidance on the U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (SOz) National Ambient Air Quality Standard (NAAQS). Your Tribe may find it importantto engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offer you consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised SOz standard. On June 3. 2010, EPA added a new primary NAAQS for S02 in orderto provide increased protection ofpublic health from S02pollution. The new standard of75 parts per billion (ppb), is attained when the 3-year average ofthe 99th percentile ofI-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. In this action EPA is only designating for the new, I-hour 75 ppb S02 standard. Establishing area designations is a key step in the process ofproviding the health protection intended by the Clean Air Act (CAA). Within two years ofpromulgation ofa new or revised NAAQS, section 107(d)(l)(A) ofthe CAA requires EPA to list and designate all areas in the country, including Indian country. as either: Attainment-areasthat meet the standard; Nonattainment-areasthat either do not meet the standard, or are contributingto a nearby area that does not meet the standard; or Unclassitiable-areas where there is insufficient information to make a determination. These designations are based on current air quality information, recommendations from State Governors and Tribal Leaders, and other relevant information discussed in the enclosed guidance document. We request and encourage your recommendation for designation ofyour area for consideration in this process.While tribes are not obligated to participate in the designations process, we invite and encourage youto do so. Please notify us ifyou are interested participating in the designations process and/or receiving consultationregarding the process. Ifyou choose to participate, we ask that you provide your designations recommendation to EPA by June 3, 2011. We are required to issue final designations by no later than June 3, 2012. We plan to announce our intended designations as early as possible after receipt ofrecommendations, but no later than 120 days priorto promulgating the final designations. Followingthe announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA maypropose to a tribe's original recommendation. The enclosed memorandum provides guidance on the process for designating areas under the new S02NAAQS. Ourdesignations will be based on the mostrecent three calendaryears of certified, quality-assured monitoring dataavailable, and any otherrelevant informationthat is provided, including refined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance or other support activities. We look forward to working with you and your staffto develop area designations under the new S02 standard in a timely manner. IfyourTribe is interested in consultation or participating in further discussions or meetings with EPA officials about the designations process, please do not hesitate to contact me or your staffmay contact AlfredaMitre, at (303) 312-6343 orMonicaMorales, at (303) 312-6936.
Sincerely,

# .LJ1~ James B. Martin· Regional Administ tor

Enclosure Cc: Don Aragon, Environmental Directori '; UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www

.epa.gov/region08

Ref: 8P-AR The Honorable Anthony Reider, President Flandreau Santee Sioux Tribe POBox 283 Flandreau, SO 57028-0283 Dear President Reider: The purpose ofthis letter is to provide you with infonnation and guidance on the U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (S02) National Ambient Air Quality Standard (NAAQS). YourTribe may find it important to engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offer you consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised S02 standard. On June 3, 2010, EPA added anew primary NAAQS for S02 in orderto provide increased protection ofpublic health from S02pollution. The new standard of75 parts per billion (ppb), is attained when the 3-yearaverage ofthe 99th percentile ofI-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hoursecondary standard. In this action EPA is onlydesignating for the new, I-hour 75 ppb S02 standard. Establishing area designations is a key step in the process ofproviding the health protection intended by the Clean AirAct (CAA). Within two years ofpromulgation ofa newor revised NAAQS, section 107(d)(l)(A) ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areasthat meet the standard; Nonattainment-areasthat either do not meet the standard, or are contributing to a nearby area thatdoes not meet the standard; or Unclassifiable-areaswhere there is insufficient infonnation to make a detennination. These designations are based on current air quality infonnation, recommendations from State Governors and Tribal Leaders, and otherrelevant information discussed in the enclosed guidance document. We request and encourage your recommendation for designation ofyour area for consideration in this process.While tribes are not obligated to participate in the designations process, we invite and encourage you to do so. Please notify us ifyou are interested participating in the designations process and/or receiving consultation regarding the process. Ifyou choose to participate, we ask that you provide your designations recommendation to EPA by June 3, 2011. We are required to issue final designations by no later than June 3, 2012. We plan to announce our intended designations as early as possible after receipt ofrecommendations, butno later than 120 days prior to promulgating the final designations. Followingthe announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may proposeto a tribe's original recommendation. The enclosed memorandum provides guidance on the process for designating areas under the new S02NAAQS. Ourdesignations will be based on the mostrecent three calendar years of certified, quality-assured monitoring data available, and any other relevant informationthat is provided, including refined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance or other support activities. We look forward to working with you and your staffto develop area designations under the new S02 standard in a timely manner. IfyourTribe is interested in consultation orparticipating in further discussions or meetings with EPA officials about the designations process, please do nothesitate to contact me or your staffmay contact Alfreda Mitre, at (303) 312-6343 orMonica Morales, at (303) 312-6936.
Sincerely,

# ~~~ James B. Martin Regional Admini

Enclosure Cc: Mark Allen, GAP CoordinatorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www

.epa.gov/region08 r'\ "

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.. Ref: 8P-AR The Honorable Tracy King, President Gros Ventre and Assiniboine Tribes RR I Box 66 Harlem, MT 59526-9455 Dear President King: The purpose ofthis letter is to provide you with information and guidance onthe U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (S02) National Ambient Air Quality Standard (NAAQS). YourTribes may find it importantto engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offer you consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised S02 standard. On June 3, 2010, EPA added a new primary NAAQS for S02 in orderto provide increased protection ofpublic health from S02pollution. The new standard of75 parts per billion (ppb), is attained when the 3-yearaverage ofthe 99th percentile ofI-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. In this action EPA is only designating for the new, I-hour75 ppb S02 standard. Establishing area designations is a key step in the process ofprovidingthe health protection intended by the Clean AirAct (CAA). Within two years ofpromulgation ofa new or revised NAAQS, section I07(d)(1)(A) ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areasthat meet the standard; Nonattainment-areasthat eitherdo not meet the standard, or are contributing to a nearby areathat does not meet the standard; or Unclassifiable-areas where there is insufficient informationto make a determination. These designations are based on current airquality information, recommendations from State Governors and Tribal Leaders, and otherrelevant information discussed in the enclosed guidance document. We request and encourage yourrecommendation for designation ofyour area for consideration in this process.While tribes are not obligatedto participate in the designations process, we invite and encourage you to do so. Please notify us ifyou are interestedparticipating in the designations process and/or receiving consultation regarding the process. Ifyou choose to participate, we ask that you provide your designations recommendation to EPAby June 3, 2011. We are required to issue final designations by no laterthan June 3, 2012. We plan to announce our intended designations as early as possible after receipt ofrecommendations, but no later than 120 days priorto promulgating the final designations. Followingthe announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPAmay propose to a tribe's original recommendation. The enclosed memorandum provides guidance onthe process for designating areas under the new S02NAAQS. Our designations will be based onthe mostrecentthree calendar years of certified, quality-assured monitoring data available, and any other relevant informationthat is provided, including refined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance or other support activities. We lookforward to working with you and your staffto develop area designations under the new S02 standard in a timely manner. Ifyour Tribes are interested in consultation orparticipating in further discussions ormeetings with EPA officials about the designations process, please do not hesitate to contact me oryour staffmay contact AlfredaMitre, at (303) 312-6343 or MonicaMorales, at (303) 312-6936.
Sincerely,

# ~~ James B. Martin Regional Adminis ator

Enclosure Cc: InaNezPerce, Environmental DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://'NWW.epa.gov/region08

Ref: 8P-AR The Honorable Michael B. Jandreau, Chairman Lower Brule Sioux Tribe 187 Oyate Circle Lower Brule, SO 57548 Dear ChairmanJandreau: The purpose ofthis letter is to provide you withinformation and guidance on the U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (S02) National Ambient Air Quality Standard (NAAQS). YourTribe may tind it important to engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offer you consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised S02 standard. On June 3, 2010, EPA added a newprimaryNAAQS for S02 in orderto provide increasedprotection ofpublic health from S02pollution. The new standard of75 parts per billion (ppb), is attained when the 3-year average ofthe 99th percentile ofI-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. In this action EPA is only designating for the new, I-hour 75 ppb S02 standard. Establishing area designations is a key step in the process ofproviding the health protection intendedby the Clean Air Act (CAA). Within two years ofpromulgation ofa new or revised NAAQS, section 107(d)(l)(A) ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areasthat meet the standard; Nonattainment-areas that eitherdo not meet the standard, or are contributing to a nearby areathat does not meet the standard; or Unclassitiable-areas where there is insufficient information to make a determination. These designations are based on current airquality information, recommendations from State Governors and Tribal Leaders, and otherrelevant information discussed in the enclosed guidance document. We request and encourage your recommendation for designation ofyour area for consideration in this process.While tribes are not obligated to participate in the designations process, we invite and encourage you to do so. Please notify us ifyou are interested participating in the designations process and/or receiving consultation regarding the process. Ifyou choose to participate, we ask that you provide your designations recommendation to EPA by June 3, 2011. We are required to issue final designations by no later than June 3, 2012. We planto announce our intended designations as early as possible afterreceipt ofrecommendations, but no later than 120 days prior to promulgating the final designations. Following the announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may propose to a tribe's original recommendation. The enclosed memorandum provides guidance on the process for designating areas under the new S02NAAQS. Our designations will be based on the most recent three calendar years of certified, quality-assured monitoring data available, and any otherrelevant informationthat is provided, including refined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance orother support activities. We look forward to working with you and your staffto develop area designations underthe new S02 standard in a timely manner. Ifyour Tribe is interested in consultation or participating in further discussions or meetings with EPA officials about the designations process, please do not hesitate to contact me or your staffmay contact Alfreda Mitre, at (303) 312-6343 orMonicaMorales, at (303) 312-6936.
Sincerely,

James B. Martin Regional Adminis

Enclosure Cc: George Honeywell, Environmental DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595 Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www,epa,gov /region08 1**UI~' r-~**  

### lVtHt\ ,; ''': ,_.." i
Ref: 8P-AR The Honorable Kim Harjo, Chairperson Northern Arapaho Tribe POBox 396 Fort Washakie, WY 82514-0217 Dear Chairperson Harjo: The purpose ofthis letter is to provide you with information and guidance onthe U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (S02) National Ambient Air Quality Standard (NAAQS). Your Tribe may find it important to engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offeryou consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised SOz standard. On June 3, 2010, EPA added a newprimary NAAQS for S02 in orderto provide increased protection ofpublic health from S02pollution. The new standard of75 parts per billion (ppb), is attained when the 3-year average ofthe 99th percentile ofI-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. 

### In this action EPA is only designating for the new, I-hour 75 ppb S02 standard. Establishing area designations is a key step in the process ofproviding the health protection intended by the Clean Air Act (CAA). Within two years ofpromulgation ofa new or revised NAAQS, section I07(d)(1)(A) ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areas that meet the standard; Nonattainment-areasthat either do not meet the standard, or are contributingto a nearby area that does not meet the standard; or Unclassifiable-areaswhere there is insufficient information to make a determination. These designations are based on current air quality information, recommendations from State Governors and Tribal Leaders, and otherrelevant information discussed in the enclosed guidance document. We request and encourage your recommendation for designation ofyour area for consideration in this process.While tribes are not obligated to participate inthe designations process, we invite and encourage you to do so. Pleasenotify us ifyou are interested participating in the designations process and/or receiving consultationregarding the process. Ifyou choose to participate, we ask that youprovide your designations recommendationto EPA by June 3, 2011. We are required to issue final designations by no later than June 3, 2012. We plan to announce ourintended designations as early as possible after receipt ofrecommendations, but no later than 120 days prior to promulgating the final designations. Followingthe announcement of intended designations, tribes will have an additional opportunity to consult onany modifications EPAmay propose to a tribe's original recommendation. The enclosed memorandum provides guidance on the process for designating areas under the new S02NAAQS. Ourdesignations will be based on the most recent three calendaryears of certified, quality-assured monitoring data available, and any other relevant information that is provided, including refined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance or other support activities. We look forward to working with you and your staffto develop area designations under the new S02 standard in a timely manner. Ifyour Tribe is interested in consultation orparticipating in further discussions or meetings with EPA officials about the designations process, please do not hesitate to contact me or your staffmay contact AlfredaMitre, at (303) 312-6343 or MonicaMorales, at (303) 312-6936.
Sincerely,

James B. Martin

# ~­ Regional

## AdminisVrat~r

Enclosure Cc: Don Aragon, Environmental DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08



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.. i Ref: 8P-AR The Honorable Leroy Spang, President Northern Cheyenne Tribe PO Box 

### 128 Lame Deer, MT 59043-0128 Dear President Spang: The purpose ofthis letter is to provide you with information and guidance on the U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (S02) National Ambient Air Quality Standard (NAAQS). Your Tribe may find it important to engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offeryou consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised S02 standard. OnJune 3, 2010, EPA added a new primary NAAQS for S02 in orderto provide increased protection ofpublic health from S02pollution. The new standard of75 parts per billion (ppb), is attained when the 3-year average ofthe 99th percentile ofI-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. In this action EPA is only designating for the new, I-hour 75 ppb S02 standard. Establishing area designations is a key step in the process ofproviding the health protection intended by the Clean Air Act (CAA). Within two years ofpromulgation ofa new or revised NAAQS, section 107(d)(l)(A) ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areas that meet the standard; Nonattainment-areas that either do not meetthe standard, or are contributingto a nearby areathat does not meet the standard; or Unclassifiable-areas where there is insufficient information to make a determination. These designations are based on current air quality information, recommendations from State Governors and Tribal Leaders, and otherrelevant information discussed in the enclosed guidance document. We request and encourage your recommendation for designation ofyour area for consideration in this process.While tribes are not obligated to participate in the designations process, we invite and encourage you to do so. Please notify us ifyou are interested participating in the designations process and/or receiving consultationregarding the process. Ifyou choose to participate, we ask that youprovide your designations recommendationto EPA by June 3, 2011. We are required to issue final designations by no later than June 3, 2012. We plan to announce our intended designations as early as possible afterreceipt ofrecommendations, but no later than 120 days priorto promulgating the final designations. Following the announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may propose to a tribe's original recommendation. The enclosed memorandum provides guidance onthe process for designating areas under the new S02NAAQS. Our designations will be based on the most recent three calendar years of certified,quality-assured monitoring data available, and any other relevant information that is provided, includingrefined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance orother support activities. We look forward to working with you and your staffto develop area designations under the new S02 standard in a timely manner. Ifyour Tribe is interested in consultation orparticipating in further discussions ormeetings with EPA officials about the designations process, please do not hesitate to contact me or your staffmay contact Alfreda Mitre, at (303) 312-6343 or Monica Morales, at (303) 312-6936.
Sincerely,

# M~ James B. Martin 

# + Regional Administrator

Enclosure Cc: Charlene Alden, Environmental DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595 Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08

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....**J'-,~~:lo ~,,;1** **'~** r.....,.• ...,**~,** Ref: 8P-AR The Honorable Gwen T. Davis, Chairwoman Northwestern Band ofthe Shoshoni Nation 353 E. Lander St. Pocatello, ID 83205 Dear Chairwoman Davis: The purpose ofthis letter is to provide you with information and guidance on the U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (SOz) National Ambient Air Quality Standard (NAAQS). YourTribe may find it important to engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offeryou consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised SOz standard. On June 3, 20I0, EPA added a newprimary NAAQS for SOz in orderto provide increased protection ofpublic health from SOlpollution. The new standard of75 parts per billion (ppb), is attained when the 3-year average ofthe 99th percentile ofI-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. 

### In this action EPA is only designating for the new, I-hour 75 ppb SOz standard. Establishing areadesignations is akey step in the process ofprovidingthe health protection intended by the Clean AirAct (CAA). Within two years ofpromulgation ofanew or revised NAAQS, section I07(d)(I)(A) ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areasthat meet the standard; Nonattainment-areasthat either do not meetthe standard, orare contributingto a nearby area that does not meet the standard; or Unclassifiable-areaswhere there is insufficient information to make a determination. These designations are based on current air quality information, recommendations from State Governors and Tribal Leaders, and otherrelevant information discussed in the enclosed guidance document. We request and encourage yourrecommendation for designation ofyour area for consideration in this process.While tribes are not obligated to participate in the designations process, we invite and encourage you to do so. Please notify us ifyou are interestedparticipating in the designations process and/or receiving consultation regarding the process. Ifyou choose to participate, we ask that you provide your designations recommendation to EPAby June 3, 2011. We are required to issue final designations by no later than June 3, 2012. We planto announce our intended designations as early as possible after receipt ofrecommendations, but no later than 120 days priorto promulgating the final designations. Followingthe announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may propose to a tribe's original recommendation. The enclosed memorandum provides guidance on the process for designating areas under the new S02NAAQS. Our designations will be based on the most recent three calendaryears of certified, quality-assured monitoring data available, and any other relevant information that is provided, includingrefined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance orother support activities. We look forward to working with you and your staffto develop area designations underthe new S02 standard in a timely manner. Ifyour Tribe is interested in consultation or participating in further discussions or meetings with EPA officials about the designations process, please do nothesitate to contact me oryour staffmay contact Alfreda Mitre, at (303) 312-6343 or MonicaMorales, at (303) 312-6936.
Sincerely,

James B. Martin Regional Admini

Enclosure Cc: Jason Walker, GAP CoordinatorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08 r " f;, 0;-. (,

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... t**~.** ':. "•.1 .,:**"~-'** Ref: 8P-AR The Honorable John Yellowbird Steele, President Oglala Sioux Tribe POBox 2070 Pine Ridge, SO 57770-2070 Dear President Yellowbird Steele: The purpose ofthis letter is to provide you with information and guidance onthe U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (S02) National Ambient Air Quality Standard (NAAQS). Your Tribe may find it importantto engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offer you consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised S02 standard. On June 3, 2010, EPA added a newprimary NAAQS for S02 in orderto provide increased protection ofpublic health from S02pollution. The new standard of75 parts per billion (ppb), is attained when the 3-yearaverage ofthe 99th percentile ofI-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. In this action EPA is only designating for the new, I-hour 75 ppb S02 standard. Establishing area designations is a key step in the process ofprovidingthe health protection intended by the Clean Air Act (CAA). Within two years ofpromulgation ofa newor revisedNAAQS, section 107(d)(1)(A) ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areasthat meet the standard; Nonattainment-areas that either do not meet the standard, or are contributingto anearby area that does not meet the standard; or Unclassifiable-areas where there is insufficient information to make a determination. These designations are based on current airquality information, recommendations from State Governors and Tribal Leaders, and otherrelevant information discussed in the enclosed guidance document. We request and encourage yourrecommendation for designation ofyour area for consideration in this process.While tribes are not obligated to participate in the designations process, we invite and encourage you to do so. Please notify us ifyou are interested participating in the designations process and/or receiving consultation regarding the process. Ifyou choose to participate, we ask that you provide your designations recommendation to EPA by June 3, 2011. We are required to issue final designations by no laterthan June 3, 2012. We plan to announce our intended designations as early as possible after receipt ofrecommendations, but no later than 120 days priorto promulgating the final designations. Following the announcement of intended designations, tribes will have an additional opportunityto consult on any modifications EPA may proposeto a tribe's original recommendation. The enclosed memorandum provides guidance on the process for designating areas under the new S02NAAQS. Ourdesignations will be based on the mostrecent three calendar years of certified, quality-assured monitoring data available, and any otherrelevant informationthat is provided, includingrefined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance or other support activities. We look forward to working with you and your staffto develop area designations under the new S02 standard in a timely manner. Ifyour Tribe is interested in consultation or participating in further discussions or meetings with EPA officials aboutthe designations process, please do not hesitate to contactme or your staffmay contact AlfredaMitre, at (303) 312-6343 or MonicaMorales, at (303) 312-6936.
Sincerely,

James B. Martin Regional Adminis

Enclosure Cc: Robert Pille, Environmental DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08**~!.l":'.** r· .**~\;~ii** ... '"

.. a ...**~'-""** • .Ii Ref: 8P-AR The Honorable Jeanine Borchardt, Chairwoman Paiute Indian Tribe ofUtah 440 North Paiute Dr CedarCity, UT 84720-6181 Dear Chairwoman Borchardt: The purpose ofthis letter is to provide you with information and guidance onthe U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (S02)National Ambient Air Quality Standard (NAAQS). Your Tribe may find it importantto engage in the process ofassigning designations for Indian country. Therefore, we would like to invite youto participate in the designations process and to offer you consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised S02 standard. On June 3, 2010, EPA added a new primary NAAQS for S02 in orderto provide increasedprotection ofpublic health from S02pollution. The new standard of75 partsper billion (ppb), is attained when the 3-year average ofthe 99th percentile ofI-hour daily maximum concentrationsdoes not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. In this action EPA is only designating for the new, I-hour 75 ppb S02 standard. Establishing area designations is a key step in the process ofproviding the health protection intended by the Clean Air Act (CAA). Within two years ofpromulgation ofa new or revised NAAQS, section 107(d)(1)(A) ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment--areasthat meet the standard; Nonattainment-areasthat either do not meet the standard, or are contributingto a nearby area that does not meetthe standard; or Unclassifiable-areas where there is insufficient informationto make a determination. These designations are based oncurrent air quality information, recommendations from State Governors and Tribal Leaders, and otherrelevant informationdiscussed in the enclosed guidance document. We request and encourage your recommendation for designation ofyour areafor consideration in this process.While tribes are not obligated to participate in the designations process, we invite and encourage you to do so. Please notify us ifyou are interested participating in the designations process and/or receiving consultationregarding the process. Ifyou choose to participate, we ask that you provide yourdesignations recommendation to EPA by June 3,2011. We are required to issue tinal designations by no later than June 3, 2012. We plan to announce our intended designations as early as possible after receipt ofrecommendations, but no later than 120 days prior to promulgating the tinal designations. Followingthe announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may propose to a tribe's original recommendation. The enclosed memorandumprovides guidance on the process for designating areas under the new S02NAAQS. Our designations will be based on the most recent three calendaryears of certified, quality-assured monitoring data available, and any other relevant information that is provided, including refined airquality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance or other support activities. We look forward to working with you and your staffto develop area designations under the new S02 standard in a timely manner. Ifyour Tribe is interested in consultation or participating in further discussions ormeetings with EPA officials about the designations process, please do not hesitate to contact me or your staffmay contact Alfreda Mitre, at (303)312-6343 or MonicaMorales, at (303) 312-6936.
Sincerely,

James B. Marti Regional Adminis

Enclosure Cc: Gaylord Robb, Environmental DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://'NWW.epa.gov/region08

Ref: 8P-AR The Honorable Rodney Bordeaux,President Rosebud Sioux Tribe POBox430 Rosebud, SO 57570-0658 Dear President Bordeaux: The purpose ofthis letter is to provide you with information and guidance on the U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (S02) National Ambient Air Quality Standard (NAAQS). YourTribe may find it important to engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to otferyou consultation: We want to ensure early, transparent and effective communication in proposing area designations for the revised S02 standard. On June 3, 2010, EPA added a new primary NAAQS for S02 in orderto provide increased protection ofpublic health from S02pollution. The new standard of75 parts per billion (ppb), is attained when the 3-year average ofthe 99th percentile ofI-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. In this action EPA is only designating for the new, I-hour 75 ppb S02 standard. Establishing area designations is a key step in the process ofprovidingthe health protection intended by the Clean Air Act (CAA). Within two years ofpromulgation ofa new or revised NAAQS, section 107(d)(1)(A) ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areasthat meet the standard; Nonattainment-areasthat either do not meet the standard, or are contributing to a nearby area that does not meet the standard; or Unclassifiable-areas where there is insufficient informationto make a determination. These designations are based on current air quality information, recommendations from State Governors and Tribal Leaders, and otherrelevant information discussed in the enclosed guidance document. We request and encourage your recommendation for designation ofyour area for consideration in this process.While tribes are not obligated to participate in the designations process, we invite and encourage you to do so. Please notify us ifyou are interested participating in the designations process and/or receiving consultation regarding the process. Ifyou choose to participate, we ask that you provide your designations recommendationto EPAby June 3, 2011. We are required to issue final designations by no later than June 3, 2012. We plan to announce our intended designations as early as possible afterreceipt ofrecommendations, but no laterthan 120 dayspriorto promulgating the final designations. Following the announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA maypropose to a tribe's original recommendation. The enclosed memorandum provides guidance on the process for designating areas under the new S02NAAQS. Our designations will be based onthe mostrecent three calendar years of certified, quality-assured monitoring data available, and any otherrelevant information that is provided, including refined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance or other support activities. We look forward to working with you andyour staffto develop area designations underthe new S02 standard in a timely manner. Ifyour Tribe is interested in consultation orparticipating in further discussions ormeetings with EPA officials about the designations process, please do nothesitate to contact me oryour staffmay contact Alfreda Mitre, at (303) 312-6343 orMonica Morales, at (303) 312-6936.
Sincerely,

James B. Martin_ Regional AdminGft'ator

Enclosure Cc: Kevin Kvame, Environmental DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595 Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08**'\~** A!"'>, ,... (' . " lVi;:"u

## <**t:"·~ ~;.;**  j Ref: 8P-AR The Honorable Robert Shepherd, Chainnan Sisseton-Wahpeton Oyate POBox 509 Agency Village, SD 57262-0509 Dear Chainnan Shepherd: The purpose ofthis letter is to provide you with infonnation and guidance onthe U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (S02) National Ambient AirQuality Standard (NAAQS). YourTribe may find it importantto engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offeryou consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised S02 standard. On June 3, 2010, EPA added a new primary NAAQS for S02 in orderto provide increased protection ofpublic health from S02pollution. The new standard of75 parts per billion (ppb), is attained when the 3-year average ofthe 99th percentile ofI-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. In this action EPA is only designating for the new, I-hour 75 ppb S02 standard. Establishing areadesignations is a key step in the process ofproviding the health protection intended by the Clean AirAct (CAA). Within two years ofpromulgation ofa new or revised NAAQS, section 107(d)(I)(A)ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areasthat meet the standard; Nonattainment-areasthat either do not meet the standard, or are contributingto a nearby areathat does not meetthe standard; or Unclassifiable-areaswhere there is insufficient infonnation to make a determination. These designations are based on current air quality infonnation, recommendations from State Governors and Tribal Leaders, and otherrelevant infonnation discussed in the enclosed guidance document We request and encourage yourrecommendation for designation ofyour area for consideration in this process,While tribes are not obligated to participate in the designations process, we invite and encourage you to do so. Please notify us ifyou are interested participating in the designations process and/or receiving consultation regarding the process. Ifyou choose to participate, we ask that you provide your designations recommendation to EPAby June 3, 2011. We are required to issue final designations by no later than June 3, 2012. We plan to announce our intended designations as early as possible after receipt ofrecommendations, but no later than 120 days prior to promulgating the final designations. Followingthe announcement of intended designations, tribes will have an additional opportunityto consult on any modifications EPA may propose to a tribe's original recommendation. The enclosed memorandum provides guidance on the process for designating areas under the new S02NAAQS. Our designations will be based on the most recent three calendar years of certified, quality-assured monitoring data available, and any otherrelevant information that is provided, including refined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance or other support activities. We look forward to working with you and your staffto develop area designations under the new S02 standard in a timely manner. Ifyour Tribe is interested in consultation orparticipating in further discussions ormeetings with EPA officials about the designations process, please do not hesitate to contact me or your staffmay contact AlfredaMitre, at (303) 312-6343 orMonica Morales, at (303) 312-6936.
Sincerely,

James B.

## Ma~~~ Regional Administrator

Enclosure Cc: MyrnaThompson, Environmental DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08

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.**~,""** ....**~.-#** .. i 

### Ref: 8P-AR The Honorable Lori Bear, Chairwoman Skull ValleyBand ofGoshute Indians P.O Box 448 Grantsville, UT 84029 Dear Chairwoman Bear: The purpose ofthis letter is to provide you with information and guidance on the U.S. Environmental ProtectionAgency's (EPA) designations process for the revised sulfur dioxide (S02) National Ambient Air Quality Standard (NAAQS). YourTribe may find it important to engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offeryou consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised S02 standard. OnJune 3, 2010, EPA added a new primary NAAQS for SOl in orderto provide increased protection ofpublic health from SOlpollution. The new standard 01'75 parts per billion (ppb), is attained when the 3-yearaverage ofthe 99th 

### percentile ofl-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. In this action EPA is only designating for the new, l-hour75 ppb SOl standard. Establishing areadesignations is a key step in the process ofprovidingthe health protection intended by the Clean Air Act (CAA). Within two years ofpromulgation ofa new or revised NAAQS, section 107(d)(1 )(A) ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areas that meet the standard; Nonattainment-areas that either do not meet the standard, orare contributingto a nearby areathat does not meet the standard; or Unclassifiable-areas where there is insufficient information to make a determination. These designations are based on current air quality information, recommendations from State Governors and Tribal Leaders, and otherrelevant information discussed in the enclosed guidance document. We request and encourage your recommendation for designation ofyour area for consideration in this process.While tribes are not obligated to participate in the designations process, we invite and encourage you to do so. Please notify us ifyou are interested participating in the designations process and/orreceiving consultationregarding the process. Ifyou choose to participate, we ask that youprovide your designations recommendation to EPA by June 3, 2011. We are required to issue tinal designations by no later than June 3, 2012. We plan to announce our intended designations as early as possible after receipt ofrecommendations, but no later than 120 days prior to promulgating the final designations. Following the announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may propose to a tribe's original recommendation. The enclosed memorandum provides guidance on the process for designating areas under the new S02NAAQS. Our designations will be based on the mostrecent three calendaryears of certified, quality-assured monitoring data available, and any otherrelevant information that is provided, including refinedairquality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance or other support activities. We look forward to working with you and your staffto develop area designations under the new S02 standard in a timely manner. IfyourTribe is interested in consultation orparticipating in further discussions ormeetings with EPA officials about the designations process, please do not hesitate to contact me or your staffmay contact AlfredaMitre, at (303) 312-6343 or MonicaMorales, at (303) 312-6936.
Sincerely,

James B. Martin**-"""'~'-_** Regional Admini

Enclosure Cc: Nicole Howell, Environmental DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08

Ref: 8P-AR The Honorable Jim Newton, Acting Chairman Southern Ute Indian Tribe POBox 737 Ignacio, CO 81137-0737 Dear Acting ChairmanNewton: The purpose ofthis letter is to provide you with information and guidance on the U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (S02) National Ambient Air Quality Standard (NAAQS). Your Tribe may tind it important to engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offeryou consultation. We want to ensureearly, transparent and effective communication in proposing area designations for the revised S02 standard. OnJune 3, 2010, EPA added a new primary NAAQS for S02 in orderto provide increased protection ofpublic health from S02pollution. The new standard of75 parts per billion (ppb), is attained when the 3-year average ofthe 99th percentile of 1-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. 

### In this action EPA is only designating for the new, 1-hour75 ppb S02 standard. Establishing areadesignations is a key step in the process ofproviding the health protection intended by the Clean Air Act (CAA). Within two years ofpromulgation ofa new or revised NAAQS, section 107(d)(1)(A) ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areasthat meet the standard; Nonattainment-areasthat either do not meet the standard, or are contributing to a nearby area that does not meet the standard; or Unclassifiable-areas where there is insufficient informationto make a determination. These designations are based on current air quality information, recommendations from State Governors and Tribal Leaders, and otherrelevant information discussed in the enclosed guidance document. We request and encourage your recommendationfor designation ofyour area for consideration in this process.While tribes are not obligatedto participate in the designations process, we invite and encourage youto do so. Please notify us ifyou are interested participating in the designations process and/or receiving consultation regarding the process. Ifyou chooseto participate, we ask that you provide your designations recommendation to EPA by June 3,2011. We are required to issue final designations by no later than June 3, 2012. We plan to announce our intended designations as early as possible after receipt ofrecommendations, but no laterthan 120 days priorto promulgating the final designations. FoJlowing the announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may propose to a tribe's original recommendation. The enclosed memorandum provides guidance on the process for designating areas under the new SOzNAAQS. Our designations will be based on the mostrecentthree calendaryears of certified, quality-assured monitoring data available, and any otherrelevant informationthat is provided, including refined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance or other support activities. We look forward to working with you and your staffto develop area designations underthe new SOz standard in a timely manner. Ifyour Tribe is interested in consultation or participating in further discussions ormeetings with EPA officials about the designations process, please do not hesitate to contact me or your staffmay contact Alfreda Mitre, at (303) 312-6343 or MonicaMorales, at (303) 312-6936.
Sincerely,

James B. Martin c--r,-'_ Regional Administ

Enclosure Cc: Thomas (Tom) Johnson, Division HeadUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08



### Ref: 8P-AR The Honorable Myra Pearson, Chairwoman Spirit Lake Nation POBox 359 Fort Totten, ND 58335-0359 Dear Chairwoman Pearson: The purpose ofthis letter is to provide you with information and guidance on the U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (S02) National Ambient Air Quality Standard (NAAQS). Your Tribe may find it important to engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offer you consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised SOz standard. On June 3, 2010, EPA added a new primaryNAAQS for S02 in orderto provide increased protection ofpublic health from S02pollution. The new standard of75 parts per billion (ppb), is attained when the 3-year average ofthe 99th 

### percentile ofI-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. In this action EPA is only designating for the new, I-hour 75 ppb S02 standard. Establishing area designations is a key step in the process ofprovidingthe health protection intended by the CleanAir Act (CAA). Within two years ofpromulgation ofanew or revised NAAQS, section 107(d)(l)(A) ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areasthat meet the standard; Nonattainment-areasthat either do not meet the standard, or are contributing to a nearby areathat does not meet the standard; or Unclassifiable-areaswhere there is insufficient informationto make a determination. These designations are based on current air quality information, recommendations from State Governors and Tribal Leaders, and otherrelevant information discussed in the enclosed guidance document. We request and encourage your recommendation for designation ofyour area for consideration in this process.While tribes are not obligated to participate in the designations process, we invite and encourage you to do so. Please notify us ifyou are interested participating inthe designations process and/or receiving consultation regarding the process. Ifyou choose to participate, we ask that youprovide your designations recommendation to EPA by June 3, 2011. We are required to issue final designations by no later than June 3, 2012. We plan to announce our intended designations as early as possible after receipt ofrecommendations, but no later than 120 days priorto promulgating the final designations. Followingthe announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may propose to a tribe's original recommendation. The enclosed memorandum provides guidance on the process for designating areas under the new S02NAAQS. Our designations will be based on the most recent three calendaryears of certified, quality-assured monitoring data available, and any otherrelevant informationthat is provided, including refined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance or other support activities. We look forward to working with you and your staffto develop area designations under the new S02 standard in a timely manner. Ifyour Tribe is interested in consultation orparticipating in further discussions or meetings with EPA officials about the designations process, please do not hesitate to contact me or your staffmay contact Alfreda Mitre, at (303) 312-6343 or Monica Morales, at (303) 312-6936.
Sincerely,

# ~~.r James B. Martin Regional Administ or

Enclosure Cc: Silas Ironheart, Environmental DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08
("\ /

Ref: 8P-AR The Honorable Charles W. Murphy, Chairman Standing Rock Sioux Tribe P

## a Box 0 Fort Yates, ND 58538-5516 Dear Chairman Murphy: The purpose ofthis letter is to provide you with infonnation and guidance onthe U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (S02) National Ambient Air Quality Standard (NAAQS). YourTribe may find it important to engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offer you consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised S02 standard. OnJune 3, 2010, EPA added a new primary NAAQS for S02 in orderto provide increased protection ofpublic health from S02pollution. The new standard of75 parts per billion (ppb), is attained when the 3-year average ofthe 99th percentile of 1-hour daily maximum concentrations does notexceed 75 ppb. No changes were made to the existing 3-hour secondary standard. In this action EPA is only designating for the new, I-hour 75 ppb SOz standard. Establishing area designations is a key step in the process ofprovidingthe health protection intended by the Clean Air Act (CAA). Within two years ofpromulgation ofa newor revisedNAAQS, section 107(d)(l)(A)ofthe CAArequires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areasthat meet the standard; Nonattainment-areasthat either do not meetthe standard, orare contributingto a nearby areathat does not meetthe standard; or Unclassitiable-areas where there is insufficient infonnation to make a detennination. These designations are based on current air quality infonnation, recommendations from State Governors and Tribal Leaders, and otherrelevant infonnation discussed in the enclosed guidance document. We request and encourage your recommendationfor designation ofyour area for consideration in this process.While tribes are not obligated to participate in the designations process, we invite and encourage you to do so. Please notify us ifyou are interestedparticipating in the designations process and/or receiving consultationregarding the process. Ifyou choose to participate, we ask that you provide yourdesignations recommendation to EPA by June 3, 2011. We are required to issue final designations by no later than June 3, 2012. We plan to announce our intended designations as early as possible after receipt ofrecommendations, but no later than 120 days priorto promulgating the final designations. Followingthe announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may propose to a tribe's original recommendation. The enclosed memorandum provides guidance on the process for designating areas under the new S02NAAQS. Our designations will be based on the most recent three calendaryears of certified, quality-assured monitoring data available, and any otherrelevant information that is provided, including refined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance or other support activities. We look forward to working with you and your staffto develop area designations under the new S02 standard in a timely manner. Ifyour Tribe is interested in consultation orparticipating in further discussions ormeetings with EPA officials. about the designations process, please do not hesitate to contact me oryour staffmay contact AlfredaMitre, at (303) 312-6343 or MonicaMorales, at (303) 312-6936.
Sincerely,

James B. Martin Regional Administ ator

Enclosure Cc:

.Troy Davis, Environmental DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08

Ref: 8P-AR The Honorable Tex Hall, Chainnan Three Affiliated Tribes 404 Frontage Road NewTown, ND58763-9404 Dear Chainnan Hall: The purpose ofthis letteris to provide you with infonnation and guidance onthe U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (SOz) National Ambient Air Quality Standard (NAAQS). YourTribes may find it important to engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offeryou consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised SOz standard. On June 3, 2010, EPA added a new primary NAAQS for SOz in orderto provide increasedprotection ofpublic health from SOzpollution. The new standard of75 parts per billion (ppb), is attained when the 3-yearaverage ofthe 99th percentile ofI-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. In this action EPA is only designating for the new, I-hour 75 ppb SOz standard. Establishing area designations is a key step in the process ofproviding the health protection intended by the Clean Air Act (CAA). Within two years ofpromulgation ofa new or revisedNAAQS, section I07(d)(l)(A) ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areasthat meetthe standard; Nonattainment-areas that either do not meet the standard, or are contributing to a nearby areathat does not meet the standard; or Unclassifiable-areas where there is insufficient infonnationto make a detennination. These designations are based on current airquality infonnation, recommendations from State Governors and Tribal Leaders, and otherrelevant infonnation discussed in the enclosed guidance document. We request and encourage your recommendation for designation ofyour area for consideration in this process.While tribes are not obligated to participate in the designations process, we invite and encourage you to do so. Pleasenotify us ifyou are interestedparticipating in the designations process and/or receiving consultation regarding the process. Ifyou choose to participate, we ask that you provide your designations recommendation to EPA by June 3, 2011. We are required to issue final designations by no laterthanJune 3, 2012. We planto announce our intended designations as early as possible after receipt ofrecommendations, but no later than 120 days priorto promulgating the final designations. Following the announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may propose to a tribe's original recommendation. The enclosed memorandum provides guidance on the process for designating areas under the new S02NAAQS. Ourdesignations will be based on the most recent three calendaryears of certified, quality-assured monitoring data available, and any otherrelevant information that is provided, including refined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance orother support activities. We look forward to working with you and your staffto develop area designations under the new S02 standard in a timely manner. Ifyour Tribes are interested in consultation orparticipating in further discussions or meetings with EPA officials about the designations process, please do not hesitate to contactme oryour staffmay contactAlfredaMitre, at (303) 312-6343 or MonicaMorales, at (303) 312-6936.
Sincerely,

James B. Martin Regional Administr

Enclosure Cc: Joe Gillies Jr., Environmental DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www

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### r Ref: 8P-AR The Honorable Merle St. Claire, Chairman Turtle Mountain Band ofChippewa POBox 900 Belcourt, ND 58316-0730
Dear

### Chairman St. Claire: The purpose ofthis letter is to provide you with information and guidance onthe U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (S02) National Ambient Air Quality Standard (NAAQS). YourTribe may find it importantto engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offeryou consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised S02 standard. On June 3, 2010, EPA added a new primary NAAQS for S02 in orderto provide increased protection ofpublic health from SOzpollution. The new standard of75 parts per billion (ppb), is attained when the 3-yearaverage ofthe 99th 

### percentile of I-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. 

### In this action EPA is only designating for the new, I-hour 75 ppb SOz standard. Establishing areadesignations is a key step in the process ofproviding the health protection intended by the Clean AirAct (CAA). Withintwo years ofpromulgation ofa new or revised NAAQS, section 107(d)(1)(A) ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areasthat meet the standard; Nonattainment-areasthat either do not meetthe standard, orare contributing to a nearby areathat does not meet the standard; or Unclassifiable--areas where there-is insufficient informationto make a determination. These designations are based on current airquality information, recommendations from State Governors and Tribal Leaders, and otherrelevant information discussed in the enclosed guidance document. We request and encourage your recommendation for designation ofyour area for consideration in this process.While tribes are not obligated to participate in the designations process, we invite and encourage you to do so. Please notify us ifyou are interested participating in the designations process and/orreceiving consultationregarding the process. Ifyou choose to participate, we ask that you provide your designations recommendation to EPA by June 3, 2011. We are required to issue final designations by no later than June 3, 2012. We plan to announce our intended designations as early as possible after receipt ofrecommendations, but no later than 120 days priorto promulgating the final designations. Following the announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may propose to a tribe's original recommendation. The enclosed memorandum provides guidance on the process for designating areas under the new S02NAAQS. Ourdesignations will be based on the most recent three calendaryears of certified, quality-assured monitoring data available, and any otherrelevant information that is provided, including refined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance or other support activities. We look forward to working with you and your staffto develop area designations under the new S02 standard in a timely manner. Ifyour Tribe is interested in consultation or participating in further discussions'or meetings with EPA officials about the designations process, please do not hesitate to contactme oryour staffmay contact AlfredaMitre, at (303) 312-6343 or MonicaMorales, at (303) 312-6936.
Sincerely,

James B. Martin Regional Administ tor

# ~~

Enclosure Cc: Rhonda Azure, Environmental DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595 Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08**p,~~** 

### ,." /.

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.. <'#" ;. j Ref: 8P-AR The Honorable Richard Jenks, Chainnan Ute Indian Tribe POBox 190 Fort Duchesne, UT 84026-0460 Dear ChainnanJenks: The purpose ofthis letter is to provide you with infonnation and guidance on the 

## u.s. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (S02) National Ambient Air Quality Standard (NAAQS). YourTribe may find it important to engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offeryou consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised S02 standard. On June 3, 2010, EPA added a new primary NAAQS for S02 in orderto provide increased protection ofpublic health from S02pollution. The new standard of75 parts per billion (ppb), is attained when the 3-yearaverage ofthe 99th percentile on-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. In this action EPA is only designating for the new, I-hour 75 ppb S02 standard. Establishing area designations is a key step in the process ofprovidingthe health protection intended by the Clean Air Act (CAA). Within two years ofpromulgation ofa new or revised NAAQS, section 107(d)(I)(A)ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areas that meet the standard; Nonattainment-areasthat eitherdo not meet the standard, orare contributing to a nearby area that does not meet the standard; or Unclassifiable-areas where there is insufficient infonnationto make a detennination. These designations are based on current air quality infonnation, recommendations from State Governors and Tribal Leaders, and other relevant infonnation discussed in the enclosed guidance document. We request and encourage your recommendation for designation ofyour area for consideration in this process.While tribes are not obligated to participate in the designations process, we invite and encourage you to do so. Please notify us ifyou are interestedparticipating in the designations process and/or receiving consultation regarding the process. Ifyou choose to participate, we ask that you provide your designations recommendation to EPA by June 3, 2011. We are required to issue final designations by no later than June 3, 2012. We plan to announce our intended designations as early as possible after receipt ofrecommendations, butno later than 120 days priorto promulgating the final designations. Followingthe announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may propose to a tribe's original recommendation. The enclosed memorandum provides guidance on the process for designating areas under the new S02NAAQS. Ourdesignations will be based on the most recent three calendar years of certified, quality-assured monitoring data available, and any other relevant information that is provided, including refined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance orother support activities. We look forward to working with you and your staffto develop area designations underthe new S02 standard in a timely manner. Ifyour Tribe is interested in consultation or participating in further discussions or meetings with EPA officials about the designations process, please do not hesitate to contact me or your staffmay contact Alfreda Mitre, at (303) 312-6343 or Monica Morales, at (303) 312-6936.
Sincerely,

James B. Martin Regional Adminis rator

Enclosure Cc: Mike Natchees, Environmental Coordinator Manuel Myore, Energy, Minerals, & Air DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08

Ref: 8P-AR The Honorable Frances Poowegup, Vice-Chairwoman Ute Indian Tribe POBox 190 Fort Duchesne. UT 84026-0460 Dear Vice-Chairwoman Poowegup: The purpose ofthis letter is to provide you with information and guidance on the U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (S02)National Ambient Air Quality Standard (NAAQS). Your Tribe may find it importantto engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offeryou consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised S02 standard. On June 3, 2010. EPA added a newprimary NAAQS for S02 in orderto provide increased protection ofpublic health from S02pollution. The new standard of75 partsper billion (ppb), is attained when the 3-year average ofthe 99th percentile ofI-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. In this action EPA is only designating for the new. I-hour 75 ppb S02 standard. Establishing areadesignations is a key step in the process ofproviding the health protection intended by the Clean Air Act (CAA). Within two years ofpromulgation ofa new or revised NAAQS, section 107(d)(I)(A) ofthe CAArequires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areas that meet the standard; Nonattainment-areasthat eitherdo not meet the standard, orare contributingto a nearby area thatdoes not meet the standard; or Unclassifiable-areas where there is insufficient information to make a determination. These designations are based oncurrent air quality information, recommendations from State Governors and Tribal Leaders, and otherrelevant information discussed in the enclosed guidance document. We request and encourage your recommendation for designation ofyour area for consideration in this process.While tribes are not obligated to participate in the designations process, we invite and encourage you to do so. Please notify us ifyou are interested participating in the designations process and/or receiving consultation regarding the process. Ifyou choose to participate, we ask that you provide your designations recommendation to EPA by June 3, 2011. We are required to issue final designations by no later than June 3, 2012. We plan to announce our intended designations as early as possible after receipt ofrecommendations, but no later than 120 days prior to promulgating the final designations. Followingthe announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may propose to a tribe's original recommendation. The enclosed memorandum provides guidance on the process for designating areas under the new S02NAAQS. Our designations will be based on the most recent three calendar years of certified, quality-assured monitoring data available, and any other relevant information that is provided, including refined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance orother support activities. We look forward to working with you and your staffto develop area designations under the new S02 standard in a timely manner. Ifyour Tribe is interested in consultation or participating in further discussions ormeetings with EPA officials about the designations process, please do not hesitate to contact me oryour staffmay contact Alfreda Mitre, at (303) 312-6343 or MonicaMorales, at (303) 312-6936.
Sincerely,

James B. Martin' Regional Administr tor

Enclosure Cc: Mike Natchees, Environmental Coordinator Manuel Myore, Energy, Minerals, & Air DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www

.epa.gov/region08

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.... ..,_ ••" Ref: 8P-AR The Honorable Phillip Chimburas, Councilman Ute Indian Tribe POBox 190 Fort Duchesne, UT 84026-0460 Dear Councilman Chimburas: The purpose ofthis letter is to provide you with information and guidance on the U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (S02) National Ambient Air Quality Standard (NAAQS). Your Tribe may find it important to engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offer you consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised S02 standard. On June 3, 2010, EPA added a newprimary NAAQS for S02 in orderto provide increasedprotection ofpublic health from S02pollution. The new standard of75 parts per billion (ppb), is attained when the 3-yearaverage ofthe 99th percentile of 1-hour daily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. 

### In this action EPA is only designating for the new, 1-hour 75 ppb S02 standard. Establishing area designations is a key step in the process ofproviding the health protection intended by the Clean Air Act (CAA). Within two years ofpromulgation ofa new or revised NAAQS, section 107(d)(1)(A) ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areas that meet the standard; Nonattainment-areas that either do not meet the standard, or are contributingto a nearby area that does not meet the standard; or Unclassifiable-areas where there is insufficient information to make a determination. These designations are based on current air quality information, recommendations from State Governors and Tribal Leaders, and other relevant information discussed in the enclosed guidance document. We request and encourage yourrecommendation for designation ofyour area for consideration in this process.While tribes are not obligated to participate in the designations process, we invite and encourage you to do so. Please notify us ifyou are interested participating in the designations process and/orreceiving consultation regarding the process. Ifyou choose to participate, we ask that you provide your designations recommendationto EPA by June 3, 2011. We are required to issue final designations by no laterthan June 3, 2012. We plan to announce ourintended designations as early as possible after receipt ofrecommendations, but no laterthan 120 days priorto promulgating the final designations. Followingthe announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may propose to a tribe's original recommendation. The enclosed memorandum provides guidance onthe process for designating areas under the new S02NAAQS. Ourdesignations will be based on the mostrecent three calendar years of certified, quality-assured monitoring data available, and any other relevant information that is provided, including refined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance orother support activities. We look forward to working with you and your staffto develop area designations under the new S02 standard in a timely manner. Ifyour Tribe is interested in consultation orparticipating in further discussions or meetings with EPA officials about the designations process, please do not hesitate to contact me or your staffmay contact Alfreda Mitre, at (303) 312-6343 or MonicaMorales, at (303) 312-6936.
Sincerely,

James B. Martin Regional Admims ator

Enclosure Cc: MikeNatchees, Environmenta1 Coordinator Manuel Myore, Energy, Minerals, & Air DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08

Ref: 8P-AR The Honorable Stewart Pike, Councilman Ute Indian Tribe POBox 190 Fort Duchesne, UT 84026-0460 Dear Councilman Pike: Thepurpose ofthis letter is to provide you with information and guidance on the U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (S02)National Ambient Air Quality Standard (NAAQS). YourTribe may find it important to engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offer you consultation. We wantto ensure early, transparent and effective communication in proposing area designations for the revised S02 standard. OnJune 3, 2010, EPA added a new primary NAAQS for S02 in orderto provide increased protection ofpublic health from S02pollution. The new standard of75 parts per billion (ppb), is attained when the 3-year average ofthe 99th percentile ofI-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. In this action EPA is onlydesignating for the new, I-hour 75 ppb S02 standard. Establishing area designations is a key step in the process ofprovidingthe health protection intended by the Clean Air Act (CAA). Within two years ofpromulgation ofa new or revised NAAQS, section 107(d)(l)(A) ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areasthat meet the standard; Nonattainment-areas that either do not meet the standard, or are contributingto a nearby area that does not meet the standard; or Unclassifiable-areas where there is insufficient information to make a determination. These designations are based oncurrent air quality information, recommendations from State Governors and Tribal Leaders, and other relevant information discussed in the enclosed guidance document. We request and encourage your recommendation for designation ofyour area for consideration in this process.While tribes are not obligated to participate in the designations process, we invite and encourage you to do so. Pleasenotify us ifyou are interested participating in the designations process and/or receiving consultationregarding the process. Ifyou choose to participate, we ask that you provide your designations recommendationto EPA by June 3, 2011. We are required to issue final designations by no later than June 3, 2012. We planto announce our intended designations as early as possible after receipt ofrecommendations, but no later than 120days prior to promulgatingthe final designations. Following the announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may propose to a tribe's original recommendation. The enclosed memorandum provides guidance onthe process for designating areas under the new S02NAAQS. Our designations will be based on the most recentthree calendaryears of certified, quality-assured monitoring data available, and any otherrelevant information that is provided, including refined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance or other support activities. We lookforward to working with you and your staffto develop area designations under the new S02 standard in a timely manner. Ifyour Tribe is interested in consultationorparticipating in further discussions ormeetings with EPA officials about the designations process, please do not hesitate to contact me or your staffmay contact Alfreda Mitre, at (303) 312-6343 orMonica Morales, at (303) 312-6936.
Sincerely,

James B. Martin Regional Administ ator

Enclosure Cc: MikeNatchees, Environmental Coordinator Manuel Myore, Energy, Minerals, & Air DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08

Ref: 8P-AR The Honorable Irene Cuch, Councilwoman Ute Indian Tribe POBox 190 Fort Duchesne, UT 84026-0460 Dear Councilwoman Cuch: The purpose ofthis letter is to provide you with information and guidance on the U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (S02) National Ambient Air Quality Standard (NAAQS). Your Tribe may find it important to engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offer you consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised S02 standard. OnJune 3, 2010, EPA added a newprimaryNAAQS for S02 in orderto provide increased protection ofpublic health from S02pollution. The new standard of75 parts per billion (ppb), is attained when the 3-year average ofthe 99th percentile ofI-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. 

### In this action EPA is only designating for the new, I-hour 75 ppb S02 standard. Establishing area designations is a key step in the process ofprovidingthe health protection intended by the Clean Air Act (CAA). Within two years ofpromulgation ofa newor revised NAAQS, section 107(d)(I)(A) ofthe CAA requires EPA to list and designate all areas in the country, including Indian country: as either: Attainment-areas that meet the standard; Nonattainment-areasthat eitherdo not meet the standard, or are contributingto a nearby area that does not meet the standard; or Unclassifiable-areaswhere there is insufficient information to make a determination. These designations are based on current air quality information, recommendations from State Governors and Tribal Leaders, and otherrelevant information discussed in the enclosed guidance document. We request and encourage your recommendation for designation ofyour area for consideration in this process.While tribes are not obligated to participate in the designations process, we invite and encourage you to do so. Please notify us ifyou are interested participating in the designations process and/orreceiving consultation regarding the process. Ifyou choose to participate, we ask that you provide your designations recommendation to EPAby June 3, 2011. We are required to issue final designations by no later than June 3, 2012. We plan to announce our intended designations as early as possible after receipt ofrecommendations, but no later than 120 days prior to promulgating the tinal designations. Following the announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may propose to a tribe's original recommendation. The enclosed memorandum provides guidance on the process for designating areas under the new S02NAAQS. Our designations will be based on the most recent three calendar years of certified, quality-assured monitoring data available, and any otherrelevant informationthat is provided, including refined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance or other support activities. We look forward to working with you and your staffto develop area designations under the new S02 standard in a timely manner. Ifyour Tribe is interested in consultation orparticipating in further discussions or meetings with EPA officials about the designations process, please do not hesitate to contactme or your staffmay contact Alfreda Mitre, at (303) 312-6343 or Monica Morales, at (303) 312-6936.
Sincerely,

James B. MartinRegional Adminis

Enclosure Cc: Mike Natchees, Environmental Coordinator Manuel Myore, Energy, Minerals, & Air DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08**~I** " iii**~J** e) ,« ('0' -.. " fr. r'L '.;".**~;.:1 .:..~**  L",;.; i Ref: 8P-AR The Honorable Ronald Wopsock, Councilman Ute Indian Tribe POBox 190 Fort Duchesne, UT 84026-0460
Dear Councilman Wopsock: The purpose ofthis letter is to provide you with information and guidance onthe U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (S02) National Ambient Air Quality Standard (NAAQS). YourTribe may find it important to engage inthe process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offer you consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised S02 standard. OnJune 3, 20I0, EPA added a new primary NAAQS for S02 in order to provide increased protection ofpublic health from S02pollution. The new standard of75 parts per billion (ppb), is attained when the 3-yearaverage ofthe 99th percentile ofI-hour daily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. In this action EPA is only designating for the new, I-hour 75 ppb S02 standard. Establishing areadesignations is a key step inthe process ofproviding the health protection intended by the Clean Air Act (CAA). Within two years ofpromulgation ofa new or revised NAAQS, section 107(d)(l)(A) ofthe CAA requires EPAto list and designate all areas in the country, including Indian country, as either: Attainment-areasthat meet the standard; Nonattainment-areasthat either do not meet the standard, or are contributing to a nearby areathat does not meet the standard; or Unclassifiable-areas where there is insufficient informationto make a determination. These designations are basedoncurrent air quality information, recommendations from State Governors and Tribal Leaders, and otherrelevant information discussed in the enclosed guidance document. We request and encourage yourrecommendation for designation ofyour area for consideration in this process.While tribes are not obligated to participate in the designations process, we invite and encourage you to do so. Please notify us ifyou are interested participating in the designations process and/or receiving consultationregarding the process. Ifyou choose to participate, we ask that you provide your designations recommendation to EPA by June 3, 2011. We are required to issue final designations by no later than June 3, 2012. We plan to announce our intended designations as early as possible after receipt ofrecommendations, but no later than 120 days priorto promulgatingthe final designations. Followingthe announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may proposeto a tribe's original recommendation. The enclosed memorandum provides guidance on the process for designating areas under the new S02NAAQS. Our designations will be based onthe most recent three calendaryears of certified, quality-assured monitoring data available, and any other relevant information that is provided, including refined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance or other support activities. We look forward to working with you and your staffto develop area designations under the newS02 standard in a timely manner. Ifyour Tribe is interested in consultationorparticipating in further discussions or meetings with EPA officials about the designations process, please do not hesitate to contact me oryour staffmay contact Alfreda Mitre, at (303) 312-6343 orMonica Morales, at (303) 312-6936.
Sincerely,

James B.**Martin'--r\'~'--'-­** Regional Admini

Enclosure Cc: Mike Natchees, Environmental Coordinator Manuel Myore, Energy, Minerals, & Air DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08

" ,**-~.** ..... """".- i • Ref: 8P-AR The Honorable Gary Hayes, Chainnan Ute Mountain Ute Tribe P

## a Box 11 Towaoc, CO 81334-0448 Dear Chainnan Hayes: The purpose ofthis letter is to provide you with infonnation and guidance on the U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (S02)National Ambient Air Quality Standard (NAAQS). Your Tribe may find it importantto engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offer you consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised S02 standard. On June 3, 2010, EPA added a new primary NAAQS for S02 in orderto provide increased protection ofpublic health from S02pollution. The new standard of75 parts per billion (ppb), is attained when the 3-year average ofthe 99th percentile ofI-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. In this action EPA is only designating for the new, I-hour 75 ppb S02 standard. Establishing area designations is a key step in the process ofprovidingthe health protection intended by the Clean Air Act (CAA). Within two years ofpromulgation ofa new or revised NAAQS, section 107(d)(I)(A) ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either: Attainment-areasthat meet the standard; Nonattainment-areas that either do not meet the standard, or are contributing to a nearby areathat does not meet the standard; or Unclassitiable-areas where there is insufficient infonnation to make a determination. These designations are based on current air quality infonnation, recommendations from State Governors and Tribal Leaders, and otherrelevant infonnation discussed in the enclosed guidance document. We request and encourage yourrecommendation for designation ofyour area for consideration in this process.While tribes are not obligated to participateinthe designations process, we invite and encourage you to do so. Please notifY us ifyou are interested participating in the designations process and/or receiving consultationregarding the process. Ifyou choose to participate, we ask that you provide your designations recommendation to EPA by June 3, 2011. We are required to issue final designations by no later than June 3, 2012. We plan to announce ourintended designations as early as possible after receipt ofrecommendations, but no later than 120 days prior to promulgating the final designations. Following the announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may propose to a tribe's original recommendation. The enclosed memorandumprovides guidance on the process for designating areas under the new S02NAAQS. Ourdesignations will be based on the mostrecent three calendar years of certified, quality-assured monitoring data available, and any otherrelevant information that is provided, including refined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance or other support activities. We look forward to working with you and your staffto develop area designations under the new S02 standard in a timely manner. Ifyour Tribe is interested in consultation or participating in further discussions ormeetings with EPA officials about the designations process, please do not hesitate to contact me oryour staffmay contact AlfredaMitre, at (303) 312-6343 orMonica Morales, at (303) 312-6936.
Sincerely,

James B. Martin 

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Enclosure Cc: Scott Clow, Environmental DirectorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595 Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08**~!''';~,** r':**t',,~"d'~ ,,~** **~i L..'~"**  Ref: 8P-AR The Honorable Robert Cournoyer, Chairman Yankton Sioux Tribe POBox 248 Marty, SO 57361-0248 Dear Chairman Cournoyer: The purpose ofthis letter is to provide you with information and guidance on the U.S. Environmental Protection Agency's (EPA) designations process for the revised sulfur dioxide (SOz) National Ambient Air Quality Standard (NAAQS). YourTribe may find it importantto engage in the process ofassigning designations for Indian country. Therefore, we would like to invite you to participate in the designations process and to offeryou consultation. We want to ensure early, transparent and effective communication in proposing area designations for the revised SOz standard. On June 3, 20I0, EPA added a newprimary NAAQS for SOz in orderto provide increased protection ofpublic health from SOzpollution. The new standard of75 parts per billion (ppb), is attained when the 3-year average ofthe 99th percentile ofI-hourdaily maximum concentrations does not exceed 75 ppb. No changes were made to the existing 3-hour secondary standard. In this action EPA is only designating for the new, I-hour 75 ppb SOz standard. Establishing areadesignations is a key step in the process ofproviding the health protection intended by the Clean AirAct (CAA). Within two years ofpromulgation ofanewor revised NAAQS, section 107(d)(I)(A) ofthe CAA requires EPA to list and designate all areas in the country, including Indian country, as either:**Attainment~areas** that meet the standard;**Nonattainment~areas** that eitherdo not meet the standard, orare contributing to a nearby area that does not meet the standard; or**Unclassifiable~areas** where there is insufficient information to make a determination. These designations are based on current air quality information, recommendations from State Governors and Tribal Leaders, and otherrelevant information discussed in the enclosed guidance document. We request and encourage yourrecommendation fOfdesignation ofyour area for consideration in this process.While tribes are not obligated to participate in the designations process, we invite and encourage you to do so. Please notify us ifyou are interested participating in the designations process and/or receiving consultationregarding the process. Ifyou choose to participate, we ask that youprovide your designations recommendation to EPAby June 3, 2011. We are required to issue final designations by no laterthan June 3, 2012. We plan to announce our intended designations as early as possible afterreceipt ofrecommendations, but no later than 120 days prior to promulgating the final designations. Following the announcement of intended designations, tribes will have an additional opportunity to consult on any modifications EPA may propose to a tribe's original recommendation. The enclosed memorandum provides guidance onthe process for designating areas under the new S02NAAQS. Ourdesignations will be based onthe most recent three calendar years of certified, quality-assured monitoring data available, and any other relevant information that is provided, including refined air quality dispersion modeling. As the process moves forward, we will keep you and your staffinformed ofany additional guidance or other support activities. We look forward to working with you and your staffto develop area designations under the new S02 standard in a timely manner. Ifyour Tribe is interested in consultation orparticipating in further discussions ormeetings with EPA officials about the designations process, please do nothesitate to contact me or your staffmay contact Alfreda Mitre, at (303) 312-6343 orMonicaMorales, at (303) 312-6936.
Sincerely,

James B. Martin , Regional AdministrltorEnclosure Cc: Richard Leasure, GAP Coordinator