Since the 1990s, the EPA has been requiring vehicle manufacturers to install onboard re-fueling vapor recovery systems in hopes of phasing out ____ equipment at UST facilities.

• A. Spill buckets
• B. Interstitial sensors
• C. SIR monitors
• D. One of the stages

Answer: (D)

Onboard refueling vapor recovery (ORVR) systems in vehicles capture most vapors at the source during fueling. Because these vapors are already handled by the vehicle’s system, the EPA has moved to phase out the vapor recovery equipment that operates at the dispensing site to capture vapors—Stage II vapor recovery—at UST facilities. The other items listed serve spill control or leak-detection functions and aren’t the target of this ORVR-driven phase-out. So the concept tested is phasing out one of the stages of vapor recovery, specifically Stage II equipment.