WA UST Site Assessor Exam
Question 1: What is the hold time for soil and preserved GW
GRO samples?
CORRECT ANSWER : 14 days
Question 2: Is an ICC certification needed to install an AST?
CORRECT ANSWER : No
Question 3: Flammability limits of gasoline
CORRECT ANSWER : 1.4 to 7.6%
Question 4: How many days do you have from a tank closure
to report/provide the UST checklist to ECY?
CORRECT ANSWER : 30 days
Question 5: MTCA Method A lead CUL, soil
CORRECT ANSWER : 250 mg/kg
Question 6: MTCA Method A lead CUL, GW
CORRECT ANSWER : 15 ug/L
Question 7: Is the vadose zone saturated or unsaturated?
CORRECT ANSWER : Unsaturated
Question 8: List in order of most mobile to least mobile: Bunker C, heating oil, diesel, gasoline
CORRECT ANSWER : Gasoline, diesel, heating oil, Bunker
C
Question 9: Is oxygenated gasoline more or less likely to
dissolve in water?
CORRECT ANSWER : More likely; fuel additives like
MTBE are more soluble than gasoline
Question 10: Where to sample on dispenser?
CORRECT ANSWER : 2 feet below where the piping enters
the UST
Question 11: Where to sample along piping?
CORRECT ANSWER : Every 50 linear feet and along
joints/elbows
Question 12: How many GW samples are needed after
decommissioning if a release to GW is confirmed, and where relative to the tank?
CORRECT ANSWER : 3; 1 upgradient, 2 downgradient
Question 13: What vapor is an FID used to measure?
CORRECT ANSWER : Methane
Question 14: What is a PID measuring?
CORRECT ANSWER : Mixture of all volatiles
Question 15: What conditions might impede a PID?
CORRECT ANSWER : Moisture/humidity, dust,
transformers, power lines
Question 16: What UST capacity does not require a site
assessment at closure?
CORRECT ANSWER : Less than 110 gallons
Question 17: Purpose of a site check
CORRECT ANSWER : To investigate a UST site for the
presence of a release when evidence indicated that a release may have occurred
Question 18: Purpose of a site assessment
CORRECT ANSWER : To investigate a UST site at the time
of closure or change-in-service to determine if a release has occurred
Question 19: Site check vs. site assessment
CORRECT ANSWER : A site check is an investigation of a
UST site for a release when evidence indicates that one many have occurred; a site assessment determines if a release has occurred
Question 20: If a confirmed release is identified and reported
within 24 hours, what is and is not required?