EIE426 Fuel Tank Replacement

Coffman provided civil, structural, mechanical, and electrical engineering services for the design and construction of four new aboveground fuel tanks—two 25,000-gallon tanks to replace existing tanks 55 and 56 and two 30,000-gallon tanks to replace tanks 3351-1 and 3351-2. All four existing tanks were demolished.

The structural scope of work included the design of two thickened edge concrete slab foundations that each support two diesel fuel tanks. A tanker truck access concrete slab was included for vehicular traffic accessing the tanks outside Building 3351. A catwalk landing and stair was designed for maintenance access to the top of tanks 55 and 56. The civil components included site development, including area grading, utilities construction, tank siting, access drive, tanker truck parking for unloading, and unobstructed space considerations. The design also provided protection from vehicular damage to piping and tank facilities along the travel-way perimeter. The mechanical design replaced two existing 25,000-gallon tanks with two new government-furnished tanks. The design included piping, appurtenances, and specifications to support the installation of the new tanks. These tanks were connected to an existing pumping header inside an adjacent building via buried double-wall flexible piping and transition sumps with leak detection. The piping arrangement included anti-siphon valves, fusible links, and valving to allow transfer between tanks.

The two new 30,000-gallon tanks connect to an existing piping system that connects a rail line with a pump building and a truck fill station. The piping arrangement included fusible links, valving, and backflow prevention to bypass or transfer between tanks. The existing diesel fuel delivery pump was replaced with two new in-tank pumps, and pump controls were integrated with existing truck fill station controls. The existing tank farm emergency shutdown system was expanded to include the new tanks, with a hand station added at the new tank location. Lighting was provided for the tank access stairs, platform, and top of tanks. Coffman provided new fuel level and leak detection sensors for the new tanks that integrate into an existing fuel level controller. The team also replaced and updated the existing fuel, electrical, and communications systems at both sites, and ran new electrical and communication lines from the new tanks to their associated building in an underground trench.

For the 25,000-gallon tanks, the design provided new fuel level and leak detection sensors, tank lighting, tanker truck access lighting, and tank grounding. The existing fuel oil pumping system in Building 3351 was modified to function with the new tanks properly.