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Subsurface Utility Engineering (SUE) Services
Reliable Utility Data for Safer, Smarter Infrastructure Projects
On The Mark Locators provides comprehensive Subsurface Utility Engineering (SUE) Services to reduce risk, eliminate utility conflicts, and support informed design and construction decisions. Our SUE solutions align with ASCE 38 Utility Quality Levels (QL-D through QL-A) and are trusted by engineers, utilities, and owners across MD, PA, DE, NJ, DC, and VA.
Who Our SUE Services Are For
Our Subsurface Utility Engineering Services are designed for:
- Civil, Structural & Transportation Engineers
- Utility Owners & Operators
- Public Works & Municipal Agencies
- Facility Owners & Developers
- Design-Build & Construction Teams
Whether you’re in early planning or final design, On The Mark Locators provides the utility intelligence required to protect assets and control project costs.
ASCE 38 Utility Quality Levels (QL-D → QL-A)
We follow the ASCE 38-22 Standard to deliver utility information at the appropriate level of confidence for your project.

QL-D – Records Research
Review of existing utility records and as-built drawings . Ideal for early planning and feasibility studies

QL-C – Surface Feature Mapping
Identification of visible utility features . Correlation with records data

QL-B – Designating Utilities
Electromagnetic (EM) and GPR Utility Locating Horizontal utility positioning for conflict avoidance

QL-A – Test Hole Verification
Vacuum excavation to confirm utility location and depth. Survey-grade accuracy for final design and construction
These quality levels are critical for Transportation Agencies, Aviation & Airports, and Municipal Governments seeking defensible utility data.
Field Markings to Survey-Grade Mapping
Our SUE process transitions field utility markings into survey-grade mapping, ensuring seamless integration into engineering and construction workflows.
- Field designations coordinated with licensed surveyors
- Precise horizontal and vertical utility data
- Reduced design conflicts and change orders
This service is essential for Water & Wastewater Utilities, Higher Education campuses, and Industrial & Manufacturing facilities throughout MD, PA, DE, NJ, DC, and VA
Why Choose On The Mark Locators for SUE?
- ASCE 38-compliant SUE services
- Advanced EM and GPR utility detection
- Survey-grade mapping and CAD deliverables
- GIS-ready data for long-term asset management
- Service coverage across MD, PA, DE, NJ, DC, and VA