Propane Refilling! All sizes. Fast, friendly & honest Service! Employees at Bi-State Landscape Supply Inc. have been certified by the Missouri Propane Gas Commission after completing a training program. The training program included an onsite instructor, curriculum based on PERC’s Certified Employee Training Program, written exam and hands on training. The curriculum covered state rules and regulations on handling liquefied petroleum gases. It is a nationally recognized program by the National Propane Gas Association.