New Technology Keeps Storage Tanks Safe

America’s 180,000 retail service stations hold over 2 billion gallons of gasoline and diesel fuel at any given time – primarily in underground tanks – ready to deliver the fuel you need to get to work, school, shopping and home again. Just as important, new equipment and tank-monitoring technology is helping ensure these vital fuels stay where they belong, preventing underground spills and protecting the environment.

A typical gasoline station has a storage capacity of 30,000 to 40,000 gallons, which may be refilled on a weekly basis. In the past, these storage tanks were subject to spills from overfilling of the tanks and from leaks caused by corrosion. Today, station owners have taken several important steps to reduce these risks.

• Underground moisture can corrode steel tank. New fiberglass tanks and steel tanks lined with fiberglass or other durable, coatings help prevent corrosion. The same high-tech coatings and linings also protect the Nation’s pipelines and above-ground storage tanks.
  
  
• Steel tanks can also be protected from corrosion with cathodic protection systems. Corrosion is essentially caused by steel slowly dissolving into the surrounding moisture. Applying a small electrical charge to the tank helps prevent the steel from dissolving. These systems also are effective for protecting pipelines and above ground storage tanks.
  
  
• Over-fill protection devices prevent operators from overfilling storage tanks:
  
  
• • Alarms let the operator know when the tank is getting full.
    
    
  • Automatic shut-off switches stop the pumping of motor fuel into the tank before the tank completely fills.
    
    
  • Ball float valves close the vent pipe when the tank is getting full. This creates a backpressure that tells the person filling the tank that the tank is almost full.
    
    
  • All tanks are equipped with catchment basins – large “buckets” located around the fill pipe that catch any motor fuel that may spill when the delivery hose is uncoupled from the fill pipe.
    
    
  • Leak detection devices send an alarm if the tank is leaking motor fuel. These systems can detect leaks as small as 0.1 gallon per hour.
    
    
  • Monitors can also detect the presence of gasoline vapors in the soils around the storage tank or can detect small amounts of fuel floating on the groundwater under the tank.
    
    
  • Tanks are also periodically tested to insure that they are tight and don’t leak.