Subsurface Utility Engineering (SUE)
Utility investigation following ASCE 38 Quality Levels A, B, C, and D for design coordination and risk reduction.
Seylone provides Subsurface Utility Engineering (SUE) services across the Northeast and Mid-Atlantic for design teams that need to characterize existing utilities before construction. SUE is the engineering practice of locating and identifying buried utilities to defined quality levels — Quality Level D (record drawings), C (surface visible features), B (surface geophysical detection), and A (direct exposure). Each level reduces risk and increases confidence as projects move from concept through detailed design.
Seylone covers the full range of SUE work, from records research and surface markout through geophysical detection and direct utility exposure. Quality Level B uses electromagnetic locating, ground-penetrating radar, and acoustic methods to designate utility horizontal positions. Quality Level A uses test pits and vacuum excavation to physically expose utilities and confirm depth, material, condition, and orientation.
What sets Seylone apart on SUE programs is integration: the same firm that runs the field investigation also performs the test pits and vacuum excavation when Quality Level A is required. There is no second contractor to mobilize, no coordination handoff between geophysics and excavation, and no schedule fragmentation between locating and exposure scopes.
The work supports utility corridor design, infrastructure renewal, transit and roadway expansion, and any project where unknown utilities create design risk. Seylone works as a specialty subcontractor to engineering primes and as a direct contractor to public agencies.
Adjacent services typically paired together.
