This project involved the design, fabrication, and installation of a multi-tank fuel storage system for a retail fueling site in St. George, Utah. The installation included five underground storage tanks with a combined system weight of approximately 157,000 pounds. The tank set consisted of three 40,000-gallon tanks, one 30,000-gallon tank, and one 3,600-gallon stainless-steel split tank, configured into two equal 1,800-gallon compartments.

A key feature of this project was the integration of large-capacity fiberglass-reinforced plastic double-wall tanks and a precision-fabricated stainless-steel split tank within a single installation. This configuration required careful coordination of engineering, manufacturing tolerances, and site logistics to ensure compatibility between differing materials, compartmentalization requirements, and regulatory standards. The stainless steel split tank was designed to meet stringent secondary-containment and performance criteria while maintaining a compact geometry within the overall system layout.

The project process emphasized structural integrity, long-term durability, and environmental protection, given the combined size and weight of the tanks, and the transportation and handling required detailed planning to maintain safety and alignment from fabrication through final placement. The installation sequence was carefully staged to accommodate site constraints and regional conditions specific to southern Utah, including soil characteristics and local compliance requirements.

Special attention was given to quality control throughout fabrication and installation, including verification of wall construction, interstitial integrity, and compartment separation. The final result is a high-capacity, multi-tank fuel storage system that demonstrates effective coordination of materials, scale, and engineering detail while meeting industry performance standards and supporting long-term operational reliability.

Award Name

STI Technology

Company Name

Watco Tanks, Inc.

Award Year

2025

Product Details

  • Utah Job
  • South St. George, Utah, United States

Date Completed

November 4, 2025

Construction Standard

STI Permatank, STI ACT-100

Overall Height

(3) 52'-0", (1) 52'-1", (1) 17'-6" = 225'-7"

Column Height

(3) 16'-6", (1) 15'-0", (1) 11'-0"

Diameter

(3) 11'-6", (1) 10'-0", (1) 6'-0"

Capacity

(3) 40,000, (1) 30,000, (1) 3,600 = 153,600

Steel Tonnage Used

70.63

Steel Thickness

5/16"

Affiliate Companies

Clay & Bailey