NewsDrop-Aug_Sept-2025

EXTERNAL AND REGULATORY AFFAIRS

By: Kyle Craig Recharge Zone Regulations Manager

As the name implies, these tanks are unseen most of the time because they are located underground where an undetected leak of a hazardous material could occur. The preservation of the aquifer is a fundamental part of the agency’s mission, and protecting against leaks from USTs helps to ensure the quality of water within the aquifer is not negatively impacted. EAA UST CONTAINMENT REQUIREMENTS In 2002, The EAA established UST rules requiring triple protection, whereas most UST systems across the nation only require mandatory secondary containment. These EAA UST rules require any UST on the Recharge Zone installed prior to October 18, 2002, must upgrade to tertiary containment or be drained and removed from service within 30 years of installation. Tertiary containment is an additional wall or barrier installed outside of a form of secondary containment and is designed to prevent the release of contents of the UST from migrating beyond the third wall before the release can be detected. As a UST system approaches its 30-year installation date, the old system is removed from the ground and disposed of at an approved landfill. If the owner chooses to install a new UST system, they must first submit an Application for Major Modification (AMM) and be approved by the EAA General Manager. The AMM and the technical documents provided prove how the new UST system will be tertiary contained. Once the AMM has been approved, the new UST system can be installed. THERE ARE OVER 350 LOCATIONS in the Recharge Zone and Contributing Zone that store chemicals and several of the facilities have Underground Storage Tanks (USTs).

PROTECTING THE RECHARGE ZONE

EAA Recharge Zone Regulation team members: Walker, Hunter, and Kyle (left to right)

ENSURING TERTIARY CONTAINMENT FOR UNDERGROUND STORAGE TANKS

A tank hold is a large hole where the USTs will be located underground at the fueling station. Once the tank hold has been dug to the proper depth, a professional geologist must certify that no sensitive features have been encountered during excavation. If a karst feature is encountered, then an Encountered Feature Plan must be submitted to the Texas Commission of Environmental Quality (TCEQ) showing how the feature will be remediated to prevent infiltration into the aquifer. THE NEXT PHASE OF INSTALLING A NEW UST IS TO DIG A NEW TANK HOLD.

The EAA’s Recharge Zone Protection Team (RZP) focuses on protecting groundwater from pollution, therefore pre serving the quality of water within the Edwards Aquifer for millions of people throughout the agency’s jurisdic tion. The Recharge Zone is the middle zone of the aquifer system and susceptible to contamination, because this is where Edwards Limestone is exposed at the surface.

Edwards Limestone in the Recharge Zone.

A tank hold being constructed

Old tanks being removed from a site

During this phase, Recharge Zone Protection staff conduct several inspections throughout the installation to verify several technical aspects of the UST system, such as the make and model of the product, installation of brine solution, testing tank pressure, installation, and function of various sensors. When the installation is completed, a storage tank registration form will be submitted, and the facility may begin filling their UST with product. AFTER THE TANK HOLD IS COMPLETED AND HAS BEEN CERTIFIED, THE UST SYSTEM CAN BE INSTALLED.

New tank installation

A site completing their new tertiary tank installation for their gas station.

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