What is QL-D?

QL-D (Quality Level D) provides only a rough sense of corridor congestion and likely utility presence through records research and documentation. It is planning-grade information that is often incomplete and must be used very carefully for any design purpose.

Method: Records Research • Purpose: Planning-Grade Information • Standard: ASCE 38-22 • Also Known As: "Records & Research"

Purpose & Limitation

QL-D provides only a rough sense of corridor congestion and likely utility presence; it is planning-grade and often incomplete.

FHWA cautions that QL-D is the lowest quality and must be used very carefully for any purpose.

Acceptable Methods (What Does Count as QL-D)

Records Research from Utility Owners and Agencies

System maps/distribution maps, utility base maps, "as-built" or record drawings, permit records, field books/notes, prior SUE deliverables, GIS exports, and digital/pdf plan sets obtained from owners or public works archives.

System Records

  • • System/distribution maps
  • • Utility base maps
  • • As-built drawings
  • • Record drawings

Administrative Records

  • • Permit records
  • • Field books/notes
  • • Construction logs
  • • Installation records

Digital Resources

  • • GIS exports
  • • Digital plan sets
  • • PDF drawings
  • • Prior SUE deliverables

Project and Archival Records

Previous project drawings, grading/roadway plans, franchise plans, developer submissions, historical atlases, legacy CAD/GIS, aerials or street-level imagery used as documentary context (still QL-D).

Historical Sources

  • • Previous project drawings
  • • Historical atlases
  • • Legacy CAD/GIS files
  • • Archival photographs

Development Records

  • • Grading/roadway plans
  • • Franchise plans
  • • Developer submissions
  • • Street-level imagery

Interviews / Oral Recollections

Discussions with knowledgeable personnel (utility owner staff, municipal operations, long-tenured foremen/inspectors) documented with names/dates and caveats.

Documentation Requirements

Who to Interview
  • • Utility owner staff
  • • Municipal operations personnel
  • • Long-tenured foremen
  • • Experienced inspectors
Documentation Required
  • • Names and contact information
  • • Interview dates and times
  • • Reliability caveats
  • • Source credibility assessment

What Does Not Qualify (On Its Own)

Paint Marks from One-Call/811 Tickets

Construction-damage-prevention markings are not a records source and are not design-grade; do not classify them as QL-D (or any QL) without proper SUE context.

Assumptions Without a Source

"Rule-of-thumb" alignments drawn with no cited record or recollection remain unknown, not QL-D.

Minimum Workflow to Legitimately Claim QL-D

1

Scope & Request

Contact each owner; request system maps, as-builts, and GIS data for defined limits. Track request dates and file versions.

Contact Process

  • • Contact all utility owners in project area
  • • Request specific record types and formats
  • • Define clear project limits
  • • Document all request dates
  • • Track file versions and updates
2

Compile & Log Sources

Catalog every document with title, owner, date, scale, coordinate basis (if any), and caveats.

Documentation Requirements

  • • Document title and description
  • • Utility owner identification
  • • Creation/revision dates
  • • Scale and coordinate system
  • • Reliability caveats and limitations
3

Transcribe to Base

Sketch the inferred alignments from records into your utility base; keep them distinctly symbolized and tagged "ASCE 38-22 QL-D."

Mapping Requirements

  • • Use distinct symbology (dotted lines, etc.)
  • • Clear ASCE 38-22 QL-D attribution
  • • Source document references
  • • Uncertainty indicators
4

Note Conflicts & Gaps

Where records disagree (or a record conflicts with a surveyed surface feature later), retain both and flag for escalation.

Conflict Management

  • • Document all conflicting information
  • • Retain multiple versions when conflicts exist
  • • Flag areas requiring field verification
  • • Note gaps in available information

When to Escalate Beyond QL-D

Escalation Criteria

If QL-D lines intersect proposed works, upgrade to QL-C (survey of visible features + correlation) and, as needed, QL-B (surface geophysics) and QL-A (test holes) at crossings/clearances.

→ QL-C

Survey visible features and correlate with records

→ QL-B

Surface geophysics for horizontal positioning

→ QL-A

Test holes for precise 3D positioning

QL-D Best Practices

Comprehensive Research

Contact all utility owners and collect all available records within project limits.

Thorough Documentation

Catalog every source with complete metadata and reliability assessments.

Know the Limitations

Always remember QL-D is planning-grade only and requires escalation for design use.

Critical Reminder

QL-D is the starting point, not the end goal. Always plan to escalate to higher quality levels where utilities may conflict with proposed construction.

Ready to upgrade from QL-D Standards?

Contact us to learn how our Visual Ground Disturbance System can help you document and manage QL-D records research with proper source tracking and escalation workflows.

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