ASCE 38

The American Society of Civil Engineers standard that defines how existing subsurface utility data is collected, classified, and shown on drawings. Its central contribution is the four quality levels — QL-D through QL-A — that state how a given utility position was determined.

ASCE 38-22 is the current edition. Its value is that it removes ambiguity from a drawing: instead of every utility being a line of equal apparent authority, each segment carries a label saying whether it came from a record, from a surveyed surface feature, from field geophysics, or from physically exposing the pipe. Designers can then treat verified data differently from inferred data. The companion standard ASCE 75 covers recording new installations as-built.