By John Ekhtiar, VP Engineering, Convault, Inc.,
with Jeanne Murphy Murck, VP Operations, Core Engineered Solutions
Flooding of fuel storage systems can pose a serious threat to the environment. Here’s how to check your ConVault tank after a flood.
Did the Tank Float?
Some aboveground storage tanks (ASTs) will float even if they are full. ConVault tanks are heavy and resist the floatation forces. ConVault ASTs up to 2,000 gallons will not float—even if empty. Larger ConVault tanks will not float if anchored and half full of fuel.
If the tank floated, was it anchored with restraints to hold it down? Without restraints, the tank can be lifted and carried by the floodwater. Add restraints to prevent future problems. See Flooding Problems of Fuel Storage Tanks.
Did the Tank get Flooded?
ASTs pose the potential danger of emitting fuel in the floodwaters through their emergency and normal vents when floodwater replaces the fuel in the AST. The tainted floodwater can potentially pollute the soil and the drinking waters of neighboring communities.
- Did the water go over the normal vent?
- Did water go inside the tank through the normal vent?
- Was the emergency vent water-tight? If not, replace the gasket
If water went inside the primary tank, measure the water height inside the tank and pump it out. If the water completely fills the tank, it can cause petroleum product to be pushed outside the tank and cause potential contamination problems. The inside of the tank may need to be cleaned to prevent accelerated corrosion from salt water especially. That is why it is essential to pre-plan installation of the tank in a flood prone area. For more information, see Flooding Problems of Fuel Storage Tanks.
Did Water Penetrate in the Secondary Containment?
Check the secondary containment for water. If water is present, determine the source. For example, was the leak detector tube open? Was the cap on the leak detector tube not water tight? Inspect the vault for any damage that could allow water to enter the tank system. See ConVault Repair and Repaint Guidelines.
References for more Information
- Flooding Problems of Fuel Storage Tanks by John Ekhtiar – ConVault, Inc.
- ConVault Repair and Repaint Guidelines
- FEMA 543 Design Guide Facility Safety Flooding & High Winds
- FEMA Anchor Fuel tanks
- FEMA RA2 Reducing Flood Effects in Critical Facilities
- FEMA RA6 Protecting Fuel System from Flood Damage
- EPA UST Flood Guide