Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (Lock A locked padlock) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Map of Sole Source Aquifer Locations
Access the Interactive Map of Sole Source Aquifers Exit EPA’s website National Geographic Information Systems (GIS) layer of SSAs Information on sole source aquifers (SSAs) is widely used in assessments under the National Environmental Policy Act and at the state and local level. A national layer, including all available SSA coverages, is available for use in GIS. In addition to single SSA designated area polygons, some EPA regional offices have delineated GIS layers for: * Streamflow zones * Aquifer recharge areas * Other features at the land surface important for SSA designations
The SSA geospatial data set is available through for use by government agencies, private organizations, and the public. Visit data.gov to download the dataExit EPA’s website.
Sole Source Aquifers for Drinking Water
Open Sidenav Menu Close Sidenav Menu Contact Us About Sole Source Aquifers for Drinking Water Contact Us About Sole Source Aquifers for Drinking Water to ask a question, provide feedback, or report a problem. Last updated on May 7, 2026 Welcome! Please share your feedback on how we can make www.epa.gov work better for you. A red asterisk (*) indicates a required field.
Success
Thank you. Your feedback has been received.
Error
alert message Required Questions - page 1 of 2 question_55203_answer_01 How would you rate your experience on www.epa.gov today? *
0 Stars 1 Star 2 Stars 3 Stars 4 Stars 5 Stars Please explain the reason for your rating. * 400 characters allowed Would you like to take two more minutes to answer more questions to help us improve our services? Yes, keep going → No, only submit these responses Optional questions - page 2 of 2 How would you describe yourself? Business Government employee Scientist Student Other Enter other text Please tell us why you visited www.epa.gov today. 400 characters allowed Did you visit www.epa.gov to accomplish a specific task? If yes, please explain why you were able or unable to accomplish your task. 400 characters allowed How can we make www.epa.gov a more helpful website? 400 characters allowed Submit []: required