Working on a Virginia Department of Transportation (VDOT) project? Understanding Subsurface Utility Engineering (SUE) requirements is essential for compliance and project success. VDOT has some of the strictest SUE requirements in the country, and non-compliance can delay your project by months. This guide covers everything contractors and engineers need to know about VDOT’s SUE standards in 2026.
What is SUE?
Subsurface Utility Engineering (SUE) is a specialized branch of engineering that manages risks associated with underground utilities during construction projects. VDOT follows the ASCE 38 Standard (ASCE/CI 38-22, updated from the original 38-02), which defines four quality levels for utility data collection. Every VDOT project that involves excavation near existing utilities must achieve the appropriate SUE level before construction begins.
The cost of NOT doing proper SUE is staggering. A Federal Highway Administration study found that every $1 invested in SUE saves $4.62 in avoided utility conflicts, project delays, and damage claims. For a typical VDOT road widening project, that can mean hundreds of thousands of dollars in savings.
The Four SUE Quality Levels
Quality Level D (Lowest Accuracy)
Information gathered from existing utility records, as-built drawings, and verbal recollections from utility company personnel. This is the least reliable level—utility records can be decades old and frequently show utilities in the wrong location by 5-10 feet or more. Level D is acceptable only for early project planning and feasibility studies, never for construction.
Quality Level C
Involves surveying visible utility features—manholes, valve boxes, meters, fire hydrants, utility poles—and correlating them with existing records. A surveyor physically maps what’s visible on the surface and ties it to record data. Level C provides reasonable horizontal location estimates but no depth information. This level is standard for preliminary design phases of VDOT projects.
Quality Level B
Uses geophysical methods—ground penetrating radar (GPR), electromagnetic locators, acoustic pipe locators—to detect and map underground utilities without digging. Level B provides horizontal position data with typical accuracy of ±12-18 inches. This is the most commonly required level for VDOT design phases and is used to identify potential utility conflicts before they become expensive construction problems.
Quality Level A (Highest Accuracy)
The gold standard. Level A requires physically exposing the utility through excavation to determine its precise horizontal and vertical position. This is where potholing and daylighting come in—and why hydro excavation is the preferred method. Level A provides accuracy within ±6 inches horizontally and vertically, giving engineers the exact data they need to design around existing utilities.
VDOT requires Level A verification at all critical conflict points identified during Level B investigations. For major highway projects like I-64 widening, I-95 improvements, and Route 460 construction, Level A potholing is mandatory at every point where new construction comes within 24 inches of an existing utility.
When Does VDOT Require SUE?
VDOT’s Utility Manual of Instructions (MOI) requires SUE investigation for virtually all projects that involve:
- Road widening or realignment (I-64, I-95, I-81, Route 58, etc.)
- Bridge replacement or rehabilitation
- Intersection improvements and roundabout construction
- Drainage improvements where existing utilities may conflict
- Utility relocation required by road construction
- Signal and lighting installations near existing underground utilities
The level of SUE required depends on the project phase and the complexity of underground utilities in the project area. VDOT project managers and district utility engineers make the final determination, but the trend is clear: VDOT increasingly requires Level A verification for any utility conflict that could impact construction.
Why Hydro Excavation for Level A?
VDOT and ASCE 38 don’t mandate a specific excavation method for Level A verification, but hydro excavation has become the de facto standard for several reasons:
- Zero utility damage risk — Pressurized water can’t cut steel, PVC, or fiber optic cables
- Clean exposure — Utilities are visible and measurable, not obscured by mud or loose soil
- Small footprint — Potholes are typically 12-18 inches in diameter, minimizing surface disruption
- Speed — A single pothole takes 15-45 minutes with hydro excavation vs. 1-2 hours with hand digging
- VDOT preference — VDOT utility engineers consistently recommend hydro excavation in pre-construction meetings
VDOT SUE Compliance Checklist
- ☐ Confirm SUE level requirements with VDOT district utility engineer
- ☐ Hire a qualified SUE provider (PE licensed in Virginia)
- ☐ Complete Level D/C records research
- ☐ Perform Level B geophysical investigation
- ☐ Identify conflict points requiring Level A verification
- ☐ Schedule SUE Level A hydro excavation with qualified contractor
- ☐ Document utility positions (horizontal and vertical) per ASCE 38 standards
- ☐ Submit SUE report to VDOT for review
- ☐ Obtain VDOT approval before proceeding to construction
Common VDOT SUE Mistakes to Avoid
- Starting construction without completing SUE — VDOT can stop your project until verification is complete
- Using mechanical excavation for Level A — One utility strike can trigger VDOT safety reviews and project suspension
- Relying solely on Level D records — Records are frequently inaccurate, especially for utilities installed before GPS
- Not coordinating with utility owners — VDOT requires coordination with all affected utility companies before SUE work begins
- Incomplete documentation — VDOT requires precise measurements, photographs, and GPS coordinates for all Level A potholes
Beach HydroVac’s VDOT SUE Services
Beach HydroVac provides SUE Level A verification for VDOT projects across Virginia. Our VDOT-compliant hydro excavation process includes precise potholing, measurement documentation, and GPS-located data deliverables. We’ve supported projects on I-64, I-264, Route 58, and local VDOT-maintained roads throughout Hampton Roads, Richmond, and Northern Virginia.
Need SUE Level A for a VDOT project? Contact Beach HydroVac or call 757-510-5220 for a free quote. We respond within 24 hours and can schedule Level A potholing within days of your request.