UNDERGROUND STORAGE TANK (UST)
EXAM WITH QUESTIONS AND
ANSWERS.
23 CCR Article 3 vs Article 4 - ANS 3 - New tanks
4 - Existing tanks (before Jan 1 1984)
Define tank - ANS stationary device designed to contain an accumulation of hazardous
substances which is constructed primarily of non-earthen materials that provide structural
support
Pipe - ANS any pipeline or pipeline system that is used in connection with the storage of
hazardous materials AND is not intended to transport hazardous substances in commerce or bulk
to/from marine vessel
includes all parts (valves, pump units, etc.)
What are not included in the UST regulations - ANS - tanks holding hydraulic fluid for a closed
loop system (lifts)
- TIUGA
- < 55 gal drums in basement
- Liquified petroleum gas tanks
- liquid asphalt tanks
- septic tanks
- emergency containment tanks
Define underground storage tank (UST) - ANS - any one or combination of tanks (including
pipes) that is used for storage of hazardous materials and is substantially OR totally beneath the
surface of the ground (at least 10%)
UST inspection requirements - ANS Annually
pressurized piping system - ANS - most common
- submersible turbine pump (STP)
- STP at top of tank sucks product from tank and pushes it to the destination under pressure
suction piping system - ANS - pump in the dispenser sucks product and pulls it to the destination
- pump away from the tank
conventional suction system - ANS check valve at the product pipe inlet inside the tank OR
check valve in the piping
, safe suction system - ANS no check valves in tank or underground piping BUT 1 check valve in
the piping at grade below the dispenser
gravity piping system - ANS no pumps
gravity causes product to flow from higher location to lower location
remote fill line
Sumps - ANS sub surface area (pit) designed to provide access to equipment below ground
Fill sump - ANS the sump where fuel is delivered through
- can be single or multiple ports
- can be remote from the tank
Turbine sump - ANS provide access to the turbine area directly above the tank
Dispenser sump - ANS provide access to piping and other parts directly under the dispenser
Transition sump - ANS less common but allows access to piping as it transitions from above
ground to below ground
Spill buckets - ANS designed to catch product spilled during disconnection of deliver
can be near or away from the UST
discriminating sensor - ANS different alarm response for each liquid (water vs fuel)
can have different detection points
slow response and recovery
NOT COMMON
non-discriminating sensor - ANS activates the same alarm for each liquid
single detection point
quick response and recovery
MOST COMMON
line leak detectors (LLD) - ANS required for all pressurized piping
provide early detection by monitoring pipe pressure
ONLY option for SW pressurized pipe
mechanical LLD function - ANS springs open/close valve and monitor pressure once pump is
ON
1. turbine turns on
2. valve cracks open and compresses bottom spring (search for leak)
3. "search mode" (3 gal/min) product flows through pipe while pressure builds up (STEP
THROUGH TIME)
4. once pressure builds the LLD is fully open and allows product to dispense at operational rate
electronic LLD - ANS pressure/flow rate changes monitored in piping after the pump turns OFF
EXAM WITH QUESTIONS AND
ANSWERS.
23 CCR Article 3 vs Article 4 - ANS 3 - New tanks
4 - Existing tanks (before Jan 1 1984)
Define tank - ANS stationary device designed to contain an accumulation of hazardous
substances which is constructed primarily of non-earthen materials that provide structural
support
Pipe - ANS any pipeline or pipeline system that is used in connection with the storage of
hazardous materials AND is not intended to transport hazardous substances in commerce or bulk
to/from marine vessel
includes all parts (valves, pump units, etc.)
What are not included in the UST regulations - ANS - tanks holding hydraulic fluid for a closed
loop system (lifts)
- TIUGA
- < 55 gal drums in basement
- Liquified petroleum gas tanks
- liquid asphalt tanks
- septic tanks
- emergency containment tanks
Define underground storage tank (UST) - ANS - any one or combination of tanks (including
pipes) that is used for storage of hazardous materials and is substantially OR totally beneath the
surface of the ground (at least 10%)
UST inspection requirements - ANS Annually
pressurized piping system - ANS - most common
- submersible turbine pump (STP)
- STP at top of tank sucks product from tank and pushes it to the destination under pressure
suction piping system - ANS - pump in the dispenser sucks product and pulls it to the destination
- pump away from the tank
conventional suction system - ANS check valve at the product pipe inlet inside the tank OR
check valve in the piping
, safe suction system - ANS no check valves in tank or underground piping BUT 1 check valve in
the piping at grade below the dispenser
gravity piping system - ANS no pumps
gravity causes product to flow from higher location to lower location
remote fill line
Sumps - ANS sub surface area (pit) designed to provide access to equipment below ground
Fill sump - ANS the sump where fuel is delivered through
- can be single or multiple ports
- can be remote from the tank
Turbine sump - ANS provide access to the turbine area directly above the tank
Dispenser sump - ANS provide access to piping and other parts directly under the dispenser
Transition sump - ANS less common but allows access to piping as it transitions from above
ground to below ground
Spill buckets - ANS designed to catch product spilled during disconnection of deliver
can be near or away from the UST
discriminating sensor - ANS different alarm response for each liquid (water vs fuel)
can have different detection points
slow response and recovery
NOT COMMON
non-discriminating sensor - ANS activates the same alarm for each liquid
single detection point
quick response and recovery
MOST COMMON
line leak detectors (LLD) - ANS required for all pressurized piping
provide early detection by monitoring pipe pressure
ONLY option for SW pressurized pipe
mechanical LLD function - ANS springs open/close valve and monitor pressure once pump is
ON
1. turbine turns on
2. valve cracks open and compresses bottom spring (search for leak)
3. "search mode" (3 gal/min) product flows through pipe while pressure builds up (STEP
THROUGH TIME)
4. once pressure builds the LLD is fully open and allows product to dispense at operational rate
electronic LLD - ANS pressure/flow rate changes monitored in piping after the pump turns OFF
