Jump to main content or area navigation.

Contact Us

EPA's Region 6 Office

Serving: Arkansas, Louisiana, New Mexico, Oklahoma, Texas, and 66 Tribal Nations

Effects of Sole Source Aquifer Designation


An aquifer can be named a Sole Source Aquifer (SSA) by the Administrator of the Environmental Protection Agency (EPA) under Section 1424(e) of the Safe Drinking Water Act (SDWA). The intention of the program is to prevent federal funding of projects that might contaminate an aquifer which is the sole or principal source of drinking water for an area.

After designation, EPA may review projects with federal financial assistance that are located in the project review area named in the designation. The project review area includes the surface recharge area of the aquifer and the area overlying the subsurface portions of the aquifer which are connected with the recharge area. It may also include the watershed area that contributes to the surface water flowing across the aquifer. The purpose of the project review process is to identify federally assisted projects that might contaminate the aquifer and then to work with the applicants to modify those projects so as to prevent contamination of the aquifer. As a final step, federal funding can be denied if the project is not modified to remove the hazard to the aquifer.

The SSA program is not linked to other Federal environmental regulatory or remedial programs, except where Federal financial assistance is committed in a designated sole source aquifer area.

Types of Projects Reviewed

Under the provisions of the law EPA can only review projects which are located in the project review area and for which there has been an application for federal financial assistance (including loans, loan guarantees, and grants). The SSA program is not intended to be used to inhibit or stop development of landfills, publicly-owned treatment works or public facilities financed by non-Federal funds.

In addition, EPA will not review projects that are of a type or size which do not constitute a potential threat to the aquifer. For example, individual home loans are not normally reviewed under the program. However, any federally assisted project in the review area may be reviewed if EPA receives a petition which requests review and presents valid evidence of the potential threat to the aquifer from that project.

The program does not prohibit any category of activity, and does not prescribe any set of restrictions on any category of activity.

Back to Top

How the Review Process Works

After designation, EPA negotiates agreements with other federal agencies (such as the Federal Highway Administration and Department of Agriculture) that might provide financial assistance in the project review area. The agreements specify which types of activities will be referred to EPA and which types are normally not referred.

When the cooperating agency receives an application for federal financial assistance involving a project subject to EPA review, it will transmit a copy of the application to the EPA where the project materials will be evaluated to determine whether there is a potential for ground water pollution from the project. This evaluation will generally be conducted within the same time frame used by the cooperating agency in its review, usually 30 days.

In most cases the evaluation will indicate that the project does not have a significant potential to contaminate the aquifer, and the cooperating agency will be so notified. EPA might also follow one of two other paths; 1) if there is insufficient information to evaluate the project, EPA will request further information, or 2) if the project has potential to contaminate the aquifer, EPA will begin negotiations to modify the project. If negotiations to modify a potentially polluting project are not successful, EPA will begin a formal Project Review, which includes public input and can lead to denial of federal funding for the project.

History of the Project Review Process

Beginning with the Edwards Aquifer of Texas in 1975, more than seventy sole source aquifers have been designated across the United States. Under the program, thousands of projects have been evaluated by the EPA Regional Offices. Although project modifications have occurred in some cases, formal denial of funding by the EPA Administrator has never been necessary for a project. EPA Region 6 generally evaluates from 30 to 70 projects per year for the five sole source aquifers in Texas, Louisiana and Oklahoma. Some of these projects may require modification. Frequently evaluated project types include wastewater treatment plants, block grant projects under Housing and Urban Development and highway construction.

For Further Information on the Sole Source Aquifer Program

For more information please visit the EPA Region 6 SSA website

Or Contact:

Michael Bechdol
U.S. Environmental Protection Agency
Ground Water/UIC Section (6WQ-SG)
1445 Ross Avenue, Suite 1200
Dallas, Texas 75202
Phone: (214) 665-7133
Fax: (214) 665-2191

Back to Top

Drinking Water    Ground Water    Underground Injection Control

Jump to main content.