Figure 3.

Time spent inspecting by experience level. LDAR surveyors are split into two experience levels: low (25–200 sites) and high (≥700 sites), while compliance surveyors are taken as a single group. Time data is normalized to major equipment units, i.e., a well head, tank, or separator. Unshaded bar(s) indicate categories with fewer than 10 data points and insufficient data to draw conclusions. Panel (a): Detection rates generally increase with additional screening time, and for low-experience LDAR surveyors, screening units for <2 min significantly reduces detection rates. Panel (b): High-experience LDAR surveyors screen equipment for longer periods than do either low-experience LDAR or compliance surveyors. The combination of higher screening times and higher detection rates at any screening time, raises the detection rates of highly experienced LDAR surveyors.