                                       
                 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
                                   REGION IX
                              75 Hawthorne Street
                           San Francisco, CA  94105

                               September 8, 2022

Memorandum

Subject: 	Summary of Discussions Between EPA Region IX, the California Air Resources Board, and the Eastern Kern Air Pollution Control District Regarding 2019-2021 Exceedances in the Indian Wells PM10 Maintenance Area 

From:     Ashley Graham, Air Planning Office, Air and Radiation Division

To:            Docket # EPA-R09-OAR-2021-0549

From May 2022 through August 2022, staff from EPA Region IX, the California Air Resources Board (CARB), and the Eastern Kern Air Pollution Control District (EKAPCD or "District") participated in several conference calls to discuss documentation for the PM10 exceedances that occurred in the Indian Wells Valley PM10 maintenance area during 2019-2021, and the provisions to provide additional information to the EPA per the contingency plan in the Indian Wells PM10 Second 10-year Maintenance Plan. During these calls, CARB and District staff discussed analyses and documentation for each of the five exceedance days in 2019-2021 and EPA staff provided recommendations for additional analyses and supporting information that could be helpful for determining whether the exceedances should be included in the calculation to determine if the contingency plan in the Indian Wells PM10 Second Maintenance Plan has been triggered. These discussions culminated in the State's submission of documentation to the EPA on September 2, 2022. 

May 2, 2022  -  Call among staff of EPA Region IX (Ashley Graham, Anita Lee, Sheila Tsai, Lindsay Wickersham, Jennifer Williams), CARB (Alicia Adams, Peishi ("Bob") Gu, Theresa Najita, Sylvia Vanderspek, Earl Withycombe), and EKAPCD (Jeremiah Cravens, Samuel Johnson). EPA noted exceedances that occurred in 2019-2021 and asked for an update on the State's efforts to evaluate the exceedances per the contingency plan in the second maintenance plan. CARB and the District indicated that they would share draft information in a few weeks and participants agreed to reconvene to discuss the draft.

June 22, 2022  -  Call among staff of EPA Region IX (Ashley Graham, Sheila Tsai), CARB (Alicia Adams, Peishi ("Bob") Gu, Theresa Najita, Sylvia Vanderspek), and EKAPCD (Samuel Johnson). CARB acknowledged receipt of the draft analyses from EKAPCD and shared an example of documentation developed for the Imperial PM10 area. CARB provide recommendations to EKAPCD for how to assemble the information into a report.

July 5, 2022  -  Call among staff of EPA Region IX (Ashley Graham, Sheila Tsai, Jennifer Williams), CARB (Peishi ("Bob") Gu, Theresa Najita), and EKAPCD (Jeremiah Cravens, Samuel Johnson). CARB recommended specific additional information and analyses that EKAPCD could evaluate and include in the report.
July 14, 2022  -  Call among staff of EPA Region IX (Ashley Graham, Jennifer Williams), CARB (Theresa Najita), and EKAPCD (Samuel Johnson). Participants continued discussions regarding analyses and additional support that could be included in EKAPCD's report.

August 8, 2022  -  Call among staff of EPA Region IX (Ashley Graham, Sheila Tsai, Lindsay Wickersham), CARB (Rebekka Fine, Theresa Najita, Sylvia Vanderspek), and EKAPCD (Jeremiah Cravens, Samuel Johnson). Participants discussed the process for submitting information about exceedances to the EPA.





