If you have underground storage tanks (USTs), then you must do leak detection for your USTs so that to keep a danger away from you. And inventory control is a temporary leak detection method.
To do inventory control right, you have to spend time to make sure that you consistently measure the tank's contents correctly, that you don't let math errors creep into your daily and monthly calculations, and that you keep complete, easy-to-read records on file for at least a year.
Basically, inventory control requires daily measurements of tank contents and math calculations that let you compare your what you've measured to what your recordkeeping indicates you should have. If the difference between them is too large, your tank may be leaking.
When you use inventory control, you must have some equipment to help you.
1. Gauge Stick Or Other Gauges
The gauge stick used to measure the depth of liquid in an underground tank must be marked or notched to the c inch, starting with zero at the bottom end. Check your stick to be sure the end has not been worn or cut off and that the stick is not warped. The stick should be made of nonsparking material, such as wood, and varnished to minimize the creeping of fuel above the actual fuel level in the tank. Instead of using a gauge stick, you may use a mechanical or electronic tank level monitor.
Whatever measuring device you use must be capable of measuring the level of product over the full range of the tank's height to the nearest c inch.
2. Pastes For Finding Water Or Fuel
You must check for water in the bottom of the tank at least once each month by smearing a water-finding paste along the bottom of the gauge stick. When water is present, the paste will turn a brilliant red, making distinct contrast and giving an accurate water gauge which is easily visible.
Now many operators improve their stick readings by smearing a fuel-finding paste on about 6 inches of the stick where they expect the fuel level to be. Fuel-finding paste changes color when it comes in contact with fuel.
Now let's do inventory control.