Most SUE professionals understand that this is not a linear process, but the quality level basic descriptions often imply otherwise.
Many articles I read on Subsurface Utility Engineering refer to the depiction of utilities at quality levels A, B, C, an D. Obviously significant elements in the depiction of existing subsurface utilities, they may also be one of the least understood. People describe the Quality Levels in almost a linear progression of increasing quality; from the depiction of utilities by record at QLD, to designating and depiction at QLC/QLB, to excavation of a utility at a specific utility conflict point QLA; hence least to best quality. As an example of this misunderstanding, we still find published RFP’s that require the depiction of utilities meeting Quality Level A standards (or the highest quality level), in which case every foot of every utility would need to be exposed and documented. This is clearly not cost effective, and ultimately is not the intent anyway.
But as most practitioners of SUE understand, the process is anything but linear. Typically, practitioners don’t depict utilities as Quality Level D, then make another deliverable as Quality Level C, then another deliverable as Quality Level B, and finally a deliverable at Quality Level A. Existing utility deliverables typically include ALL the quality level depictions, where certain utilities were designated meeting the Quality Level B standard, and some utilities that could not be designated are included by utility record meeting the Quality Level D standard. The same deliverable may include exposure of the utility at specific locations to determine it’s type, size, material, depth and configuration at specific points meeting the Quality Level A standard.
In some cases, the linear progression of depicting utilities at quality levels may be time wasted. For example, when including utility record information on a plan only, the process of interpreting those records and making a best guess of the depiction takes a lot of time, especially when that utility depicted by record can be accurately designated anyway.
When describing Quality Levels to co-workers or clients new to the concept, I find myself describing the Quality Levels as “Source Levels”. Meaning, what is the source of the information used to depict the utilities. The source could be a utility record, a designated utility using geophysical equipment, or a test hole. Where all the sources of information can be shown on one existing utility deliverable.