Key Definitions

  • TIUGA:   Tank In an UnderGround Area
  • SPCC Plan:   Spill Prevention, Control, & Countermeasure Plan
  • APSA:   California Aboveground Petroleum Storage Act
  • CERS:   California Environmental Reporting System

 

Do I have a TIUGA?

  • Under APSA, a TIUGA applies to tanks or other containers with a volume of 55 gallons or more.
  • These tanks or containers are used to store petroleum or other regulated liquids.  See below for regulated liquids.
  • The storage tanks or containers are located on a floor and in a structure with at least 10 percent of that floor height below the ground surface.
  • Below ground surfaces include, but are not limited to, a basement, cellar, shaft, pit or vault.

What type of liquids are regulated under TIUGA?

  • Petroleum Fuel (gasoline, diesel, fuel oil, kerosene, etc)
  • Hazardous Waste
  • Lubricant (new or used motor oil, automatic transmission fluid, hydraulic fluid)
  • Petroleum based Coolant (new or used)

Aboveground Petroleum Storage Act Program

  • Effective July 1, 2018, tanks in an underground area (TIUGA) are subject to APSA.

Examples of TIUGA:

  • Emergency Generator with a Diesel Day Tank or Diesel Subbase (Belly) Tank that is below grade.
  • Emergency Generator with a Diesel Day Tank or Diesel Subbase (Belly) Tank that is below grade and has a AST supply tank located at any level.
  • Fire Pump with a Diesel Day Tank
  • Oil-filled Operational or Manufacturing Equipment (Hydraulic Lift Elevator with a Hydraulic Oil Storage Tank, oil-cooled transformer, etc.)
  • Service Station with underground fuel tanks in a concrete vault
  • Partially buried tank system that is less than 10 percent below the ground surface and situated on or above the surface of the floor.  Note: a buried tank and piping system that is at least 10 percent below the ground surface is regulated as a UST.
  • A TIUGA with less than 55 gallons of petroleum capacity may be regulated under APSA.  See Exempt from TIUGA for more details.

Exempt from TIUGA:

  • Emergency Generator with a day tank below grade that has a UST supply tank.
  • A tank facility with a TIUGA with less than 55 gallons of storage capacity of petroleum, has secondary containment, is inspected monthly, and the owner or operator maintains a log of inspection records for review by the UPA upon request.

Converting from a UST to a TIUGA:

  • A previously designated UST that is now designated as a TIUGA can be closed in CERS by selecting ‘Permanent Closure Onsite’. Note in CERS ‘This tank has been determined to be a Tank in Underground Area (TIUGA). According to APSA this tank will no longer will be regulated as a UST effective with the date of this submittal.’

What must I do?

  • Obtain applicable permits
  • Allow for direct viewing of the exterior of the tank except for the part of the tank in contact with the surface of the floor.
  • Provide sufficient secondary containment for the volume of the contents of the tank, piping, and ancillary equipment.
  • Provide applicable reporting to California Environmental Reporting System (CERS)
  • Satisfy the requirements for a Spill Prevention, Control, and Countermeasure (SPCC) Plan
    • Conduct periodic inspections of each TIUGA
    • Comply with current Federal SPCC regulations found in 40 CFR 112

How often should I perform a TIUGA inspection?

  • Written inspections need to be performed monthly.
  • A comprehensive written inspection needs to be performed annually.

What should look for during a typical TIUGA monthly inspection?

  • Are they any visible leaks around the tank and piping system?
  • Is there a visible leak inside the tank interstitial in any other other containment areas?
  • Does the tank level gauge work properly?
  • Is overfill prevention equipment (overfill mechanical valves, solenoid valves, visual and audible alarms, etc.) working correctly?
  • Is there any sign of corrosion or damage to the tank and piping system?
  • Is the spill containment clean, free of any liquids and appear to be liquid-tight?
  • Are drain valves closed?

For additional support you can contact our Professional Engineering consulting staff at Pacific Petroleum.