AQS User Support is provided through the EPA Call Center, which is operated under contract to the EPA.
The toll free number is 1-866-411-4EPA (4372). TDD: 1-866-489-4900 International callers: 1-703-679-1070
Their hours of operation are 6:00am - 9:00pm E.T. (Monday - Friday, excluding Federal holidays). You may also contact the Call Center via email (EPACALLCENTER@epa.gov) or fax (703-674-1008).
Central Data Exchange (CDX) is EPA's electronic reporting site. CDX support is available toll-free between the hours of 8:00 am and 6:00 pm (EST) at 888-890-1995 or via email at helpdesk@epacdx.net.
Contact a National or Regional EPA representative or a State, Local, or Tribal Agency representative http://www.epa.gov/airquality/airdata/ad_contacts.html
You will need Adobe Reader to view some of the files on this page. See EPA’s About PDF page to learn more.- aqs regional contacts (PDF)(1 pg, 51 K)