WA UST Site Assessor Exam Questions and Answers 2023 with complete solution

What is the hold time for soil and preserved GW GRO samples? Ans 14 days Is an ICC certification needed to install an AST? Ans No Flammability limits of gasoline Ans 1.4 to 7.6% How many days do you have from a tank closure to report/provide the UST checklist to ECY? Ans 30 days MTCA Method A lead CUL, soil Ans 250 mg/kg MTCA Method A lead CUL, GW Ans 15 ug/L Is the vadose zone saturated or unsaturated? Ans Unsaturated List in order of most mobile to least mobile: Bunker C, heating oil, diesel, gasoline Ans Gasoline, diesel, heating oil, Bunker C Is oxygenated gasoline more or less likely to dissolve in water? Ans More likely; fuel additives like MTBE are more soluble than gasoline Where to sample on dispenser? Ans 2 feet below where the piping enters the UST Where to sample along piping? Ans Every 50 linear feet and along joints/elbowsHow many GW samples are needed after decommissioning if a release to GW is confirmed, and where relative to the tank? Ans 3; 1 upgradient, 2 downgradient What vapor is an FID used to measure? Ans Methane What is a PID measuring? Ans Mixture of all volatiles What conditions might impede a PID? Ans Moisture/humidity, dust, transformers, power lines What UST capacity does not require a site assessment at closure? Ans Less than 110 gallons Purpose of a site check Ans To investigate a UST site for the presence of a release when evidence indicated that a release may have occurre