UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460

OFFICE OF AIR AND RADIATION

The Honorable Kevin McCarthy U.S. House of Representatives Washington, D.C. 20515 Dear Congressman McCarthy: Thank you for your letter dated June 10, 2014, to U.S. Environmental Protection Agency Administrator Gina McCarthy, regarding the California drought and whether it qualifies as an "exceptional event" under the Clean Air Act (CAA). The Administrator has asked that I respond on her behalf We recognize the importance of this issue for California and its local air districts and the progress you have made in protecting your citizens from the harmful effects of air pollution. We have been working and will continue to work closely with the San Joaquin Valley Air Pollution Control District (APCD) and other APCDs to resolve exceptional event requests and implementation issues. As you know, air pollution can have damaging effects on human health, including respiratory problems, hospitalization for heart or lung disease, and even premature death. In addition, air pollution can have effects on aquatic life, vegetation, and animals. For these reasons, the Clean Air Act requires the EPA to set National Ambient Air Quality Standards (NAAQS) for certain air pollutants to protect human health and the environment. That said, sometimes "exceptional events" - e.g., high wind dust events, volcanic eruptions, and wildfires - may cause high pollutant concentrations for reasons outside of the control ofstates and regulated sources. In those circumstances, the Clean Air Act allows exclusion of these eventinfluenced concentrations for regulatory purposes. While the CAA specifically defines a "meteorological event involving high temperatures or lack of precipitation" as not an exceptional event allowing the exclusion of data from regulatory decisions, the EPA believes that some drought-related exceedances and violations may be considered for exclusion under the provisions of the "Treatment of Data Influenced by Exceptional Events; Final Rule." For example, the EPA believes that an air agency can submit evidence showing that a severe drought resulted in arid conditions (e.g., lower than typical soil moisture content, decreased vegetation, etc.), which, when combined with another event (e.g., a high wind event or wildfire), could be considered eligible for exclusion. In this scenario, the EPA would consider the subsequent event, which would need to meet the provisions of the rule, as the exceptional event. It is in this spirit that we evaluate specific state requests for an Exceptional Events finding.

Internet Address (URL) • http://www.epa.gov Recycled/Recyclable • Printed with Vegetable Oil Based Inks on 100% Postconsumer, Process Chlorine Free Recycled PaperAgain, thank you for your letter. If you have further questions, please contact me or your staff may

contact Josh Lewis in the EPA's Office of Congressional and Intergovernmental Relations at lewis.joshepa.govor (202) 

### 564-2095. Sincerely, _,_l* .q-i-'

Janet G. McCabe Acting Assistant AdministratorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460

OFFICE OF AIR AND RDIATION

The Honorable Devin Nunes U.S. House of Representatives Washington, D.C. 20515 Dear Congressman Nunes: Thank you for your letter dated June 10, 2014, to U.S. Environmental Protection Agency Admiiiiistrator Gina McCarthy, regarding the California drought and whether it qualifies as an "exceptional evnt" under the Clean Air Act (CAA). The Administrator has asked that I respond on her behalf. We recognize the importance of this issue for California and its local air districts and the progress you have made in protecting your citizens from the harmful effects of air pollution. We have been orking and will continue to work closely with the San Joaquin Valley Air Pollution Control District (A?CD) and other APCDs to resolve exceptional event requests and implementation issues. As you know, air pollution can have damaging effects on human health, including respiratory piioblems, hospitalization for heart or lung disease, and even premature death. In addition, air pollution cart have effects on aquatic life, vegetation, and animals. For these reasons, the Clean Air Act requires th EPA to set National Ambient Air Quality Standards (NAAQS) for certain air pollutants to protect humai health and the environment. That said, sometimes "exceptional events" - e.g., high wind dust events, volcanic eruptions, and wildfires - may cause high pollutant concentrations for reasons outside of the control ofstates and regulated sources. In those circumstances, the Clean Air Act allows exclusion of these eventinfluenced concentrations for regulatory purposes. While the CAA specifically defines a "meteorological event involving high temperatures or lack of precipitation" as not an exceptional event allowing the exclusion of data from regulatory decisions, the EPA believes that some drought-related exceedances and violations may be considered for exclusion under the provisions of the "Treatment of Data Influenced by Exceptional Events; Final Rule." 1'or example, the EPA believes that an air agency can submit evidence showing that a severe droug1t resulted in arid conditions (e.g., lower than typical soil moisture content, decreased vegetation, tc.), which, when combined with another event (e.g., a high wind event or wildfire), could be considered eligible for exclusion. In this scenario, the EPA would consider the subsequent event, which woild need to meet the provisions of the rule, as the exceptional event. It is in this spirit that we evaluate spcific state requests for an Exceptional Events finding.

Internet Address (URL) • http:I/www.epa.gov Recycled/Recyclable • Printed with Vegetable Oil Based Inks on 100% Postconsumer, Process Chlorine Free Recycled PaperAgain, thank you for your letter. If you have further questions, please contact me or your staff may

contact Josh Lewis in the EPA's Office of Congressional and Intergovernmental Relations at lewis.joshepa.govor (202) 

### 564-2095.

Janet G. McCabe Acting Assistant AdministratorUNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460

OFFIC OF AIR AND RDIATION

The Honorable Jeff Denham U.S. House of Representatives Washington, D.C. 20515 Dear Congressman Denham: Thank you for your letter dated June 10, 2014, to U.S. Environmental Protection Agency Administrator Gina McCarthy, regarding the California drought and whether it qualifies as an "exceptional event" under the Clean Air Act (CAA). The Administrator has asked that I respond on her behalf We recognize the importance of this issue for California and its local air districts and the progress you have made in protecting your citizens from the harmful effects of air pollution. We have been 4'orking and will continue to work closely with the San Joaquin Valley Air Pollution Control District (APCD) and other APCDs to resolve exceptional event requests and implementation issues. As you know, air pollution can have damaging effects on human health, including respiratory problems, hospitalization for heart or lung disease, and even premature death. In addition, air pollution can have effects on aquatic life, vegetation, and animals. For these reasons, the Clean Air Act requires th EPA to set National Ambient Air Quality Standards (NAAQS) for certain air pollutants to protect human health and the environment. That said, sometimes "exceptional events" - e.g., high wind dust events, volcanic eruptions, and wildfires - may cause high pollutant concentrations for reasons outside of the coiitrol ofstates and regulated sources. In those circumstances, the Clean Air Act allows exclusion of these eventinfluenced concentrations for regulatory purposes. While the CAA specifically defines a "meteorological event involving high temperatures or lack of precipitation" as not an exceptional event allowing the exclusion of data from regulatory decisins, the EPA believes that some drought-related exceedances and violations may be considered for excl.ision under the provisions of the "Treatment of Data Influenced by Exceptional Events; Final Rule." or example, the EPA believes that an air. agency can submit evidence showing that a severe drouglt resulted in arid conditions (e.g., lower than typical soil moisture content, decreased vegetation, etc.), which, when combined with another event (e.g., a high wind event or wildfire), could be considered eligible for exclusion. In this scenario, the EPA would consider the subsequent event, which wuld need to meet the provisions of the rule, as the exceptional event. It is in this spirit that we evaluate spcific state requests for an Exceptional Events finding.

Internet Address (URL) • http://www.epa.gov Recycled/Recyclable • Printed with Vegetable Oil Based Inks on 100% Postconsumer, Process Chlorine Free Recycled Paper

### Again, thank you for your letter. If you have further questions, please contact me or your staff mafr

contact Josh Lewis in the EPA' s Office of Congressional and Intergovernmental Relations at 1ewis.joshepa.govor (202) 564-2095. Sincerely,

Janet G. McCabe Acting Assistant AdministratorOFFIC OF AIR AND R4DIATION UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460



### The Honorable David G. Valadao U.S. House of Representatives Washington, D.C. 20515 Dear Congressman Valadao: Thank you for your letter dated June 10, 2014, to U.S. Environmental Protection Agency Admiitiistrator Gina McCarthy, regarding the California drought and whether it qualifies as an "exceptional evnt" under the Clean Air Act (CAA). The Administrator has asked that I respond on her behalf. We recognize the importance of this issue for California and its local air districts and the progress you have made in protecting your citizens from the harmful effects of air pollution. We have been orking and will continue to work closely with the San Joaquin Valley Air Pollution Control District (A?CD) and other APCDs to resolve exceptional event requests and implementation issues. As you know, air pollution can have damaging effects on human health, including respiratory pioblems, hospitalization for heart or lung disease, and even premature death. In addition, air pollution can have effects on aquatic life, vegetation, and animals. For these reasons, the Clean Air Act requires the EPA to set National Ambient Air Quality Standards (NAAQS) for certain air pollutants to protect humai health and the environment. That said, sometimes "exceptional events" - e.g., high wind dust events, vçilcanic eruptions, and wildfires - may cause high pollutant concentrations for reasons outside of the conjtrol ofstates and regulated sources. In those circumstances, the Clean Air Act allows exclusion of these eventinfluenced concentrations for regulatory purposes. While the CAA specifically defines a "meteorological event involving high temperatures or lack of precipitation" as not an exceptional event allowing the exclusion of data from regulatory decisions, the EPA believes that some drought-related exceedances and violations may be considered for excii4sion under the provisions of the "Treatment of Data Influenced by Exceptional Events; Final Rule." ifor example, the EPA believes that an air agency can submit evidence showing that a severe drought resulted in arid conditions (e.g., lower than typical soil moisture content, decreased vegetation, tc.), which, when combined with another event (e.g., a high wind event or wildfire), could be considred eligible for exclusion. In this scenario, the EPA would consider the subsequent event, which wo4ild need to meet the provisions of the rule, as the exceptional event. It is in this spirit that we evaluate spcific state requests for an 

### Exceptional Events finding.

Internet Address (URL) • http:/Iwww.epagov Recycled/Recyclable I Printed with Vegetable Oil Based Inks on 100% Postconsumer, Process Chlorine Free Recycled PaperAgain, thank you for your letter. If you have further questions, please contact me or your staff my

contact Josh Lewis in the EPA's Office of Congressional and Intergovernmental Relations at lewis.josh@epa.govor (202) 

### 564-2095.

Janet G. McCabe Acting Assistant Administrator^^^EDS^;^

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^L PROT E° UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, DC. 20460

OFFIC OF AIR AND RADIATION


### The Honorable Jim Costa U.S. House of Representatives Washington, D.C. 20515 Dear Congressman Costa: Thank you for your letter dated June 10, 2014, to U.S. Environmental Protection Agency Admi*istrator Gina McCarthy, regarding the California drought and whether it qualifies as an "exceptional evnt" under the Clean Air Act (CAA). The Administrator has asked that I respond on her behalf. We recognize the importance of this issue for California and its local air districts and the progres you have made in protecting your citizens from the harmful effects of air pollution. We have been wrking and will continue to work closely with the San Joaquin Valley Air Pollution Control District (ACD) and other APCDs to resolve exceptional event requests and implementation issues. As you know, air pollution can have damaging effects on human health, including respiratory problems, hospitalization for heart or lung disease, and even premature death. In addition, air pollution cai have effects on aquatic life, vegetation, and animals. For these reasons, the Clean Air Act requires th EPA to set National Ambient Air Quality Standards (NAAQS) for certain air pollutants to protect humai health and the environment. That said, sometimes "exceptional events" - e.g., high wind dust events, volcanic eruptions, and wildfires - may cause high pollutant concentrations for reasons outside of the control ofstates and regulated sources. In those circumstances, the Clean Air Act allows exclusion of these eventinfluenced concentrations for regulatory purposes. While the CAA specifically defines a "meteorological event involving high temperatures or lacl< of precipitation" as not an exceptional event allowing the exclusion of data from regulatory decisiois, the EPA believes that some drought-related exceedances and violations may be considered for exchsion under the provisions of the "Treatment of Data Influenced by Exceptional Events; Final Rule." Ij'or example, the EPA believes that an air agency can submit evidence showing that a severe droughf resulted in arid conditions (e.g., lower than typical soil moisture content, decreased vegetation, eltc.), which, when combined with another event (e.g., a high wind event or wildfire), could be considred eligible for exclusion. In this scenario, the EPA would consider the subsequent event, which woild need to meet the provisions of the rule, as the exceptional event. It is in this spirit that we evaluate spcific state requests for an Exceptional Events finding.

Internet Address (URL) • http://wwwepa.gov Recycled/Recyclable • Printed with Vegetable Oil Based Inks on 00% Postconsumer, Process Chlorine Free Recycled Paper,Again, thank you for your letter. If you have further questions, please contact me or your staff my

contact Josh Lewis in the EPA' s Office of Congressional and Intergovernmental Relations at 1ewis.joshepa.govor (202) 564-2095.

Janet G. McCabe Acting Assistant Administratorv ^ E ° ST

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^^^ UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460

OFFIC OF AIR AND RADIATION

The Honorable Jerry McNerney U.S. House of Representatives Washington, D.C. 20515 Dear Congressman McNerney: 

### Thank you for your letter dated June 10, 2014, to U.S. Environmental Protection Agency Administrator Gina McCarthy, regarding the California drought and whether it qualifies as an "exceptional event" under the Clean Air Act (CAA). The Administrator has asked that I respond on her behalf. We recognize the importance of this issue for California and its local air districts and the progrss you have made in protecting your citizens from the harmful effects of air pollution. We have been vorking and 

### will continue to work closely with the San Joaquin Valley Air Pollution Control District (iPCD) and 

### other APCDs to resolve exceptional event requests and implementation issues. As you know, air pollution can have damaging effects on human health, including respiratory problems, hospitalization for heart or lung disease, and even premature death. In addition, air pollution can have effects on aquatic life, vegetation, and animals. For these reasons, the Clean Air Act requires tlje EPA to set National Ambient Air Quality Standards (NAAQS) for certain air pollutants to protect human health and the environment. That said, sometimes "exceptional events" - e.g., high wind dust events, Volcanic eruptions, and wildfires - may cause high pollutant concentrations for reasons outside of the control ofstates and regulated sources. In those circumstances, the Clean Air Act allows exclusion of thee eventinfluenced concentrations for regulatory purposes. While the CAA specifically defines a "meteorological event involving high temperatures or lak of precipitation" as not an exceptional event allowing the exclusion of data from regulatory decis4ons, the EPA believes that some drought-related exceedances and violations may be considered for exclusion under the provisions of the "Treatment of Data Influenced by Exceptional Events; Final Rule.'l For example, the EPA believes that an air agency can submit evidence showing that a severe drouht resulted in arid conditions (e.g., lower than typical soil moisture content, decreased vegetation etc.), which, when combined with another event (e.g., a high wind event or wildfire), could be consiJered eligible for exclusion. In this scenario, the EPA would consider the subsequent event, which ould need to meet the provisions of the rule, as the exceptional event. It is in this spirit that we evaluate specific state requests for an Exceptional Events finding.

Internet Address (URL) • http://www.epagov Recycled/Recyclable • Printed with Vegetable Oil Based Inks on 100% Postconsumer, Process Chlorine Free Recycled PaperAgain, thank you for your letter. If you have further questions, please contact me or your staff nay

contact Josh Lewis in the EPA' s Office of Congressional and Intergovernmental Relations at lewis.joshepa.gov or (202) 564-2095.

Janet G. McCabe Acting Assistant Administrator