EM Line Locating · Depth · as-builts · CAD
Depth Estimation & Utility Mapping by EM.
Add the third dimension and a permanent record: estimated burial depth at every point of interest, and a marked, measured map of what's underground — the deliverable that turns a one-day locate into a lasting site asset.
Free phone consult · No pressure · Mon–Sat 8am–6pm PT
Best suited for
Why it's used
- Depth where it matters — at crossings and conflicts
- A permanent map, not just paint that washes away
- Feeds design, SUE, and as-built workflows
- Combines EM + GPR + sonde into one record
How it works
- 1
Locate the lines
Every locatable utility is found first by its best method — active/passive EM for conductive lines, sonde for drains, GPR for non-conductive and confirmation — so the map is built on a complete locate, not a partial one.
- 2
Estimate depth
At each point of interest — crossings, proposed dig locations, conflicts — burial depth is estimated from the EM signal (and confirmed by GPR where useful). Depth is taken where decisions get made, not guessed between.
- 3
Record positions
Routes and depths are captured to the accuracy the project needs — paint and flags for a same-day dig, or measured survey-grade points for a CAD map and as-built record.
- 4
Deliver the map
Output ranges from a marked-and-photographed site to a CAD utility map or as-built drawing, feeding design, subsurface utility engineering, and the next crew that has to dig here. The marks fade; the map doesn't.
Frequently asked
How accurate is EM depth estimation?
Depth estimation from EM locating is an estimate, not a survey measurement — accuracy depends on the signal quality, how isolated the line is, and the locator's technique, and it's most reliable on a clean active trace of an isolated line. It's accurate enough to plan a dig and flag conflicts; where a precise depth is critical (a tight crossing, a bore), it's confirmed by GPR and ultimately by hand-exposure or vacuum potholing. We state depths as estimates and verify the critical ones.
Why pay for a utility map instead of just paint marks?
Paint washes away in weeks; a map lasts the life of the site. If the ground will be dug more than once — a development, a campus, a managed property — a measured CAD map or as-built pays for itself by not re-locating from scratch every time, and by feeding design and conflict analysis before trenching. For a one-time backyard dig, paint is fine; for an asset you'll revisit, the map is the better buy.
Can you give us depths for engineering design?
Yes — depth at crossings and proposed alignments is one of the main reasons designers commission a locate. We capture estimated depths at the points of interest the design needs, confirm the critical ones with GPR, and deliver them in a format your engineers can use. For formal subsurface utility engineering (SUE) quality levels, see our SUE service, which this depth-and-mapping work feeds directly.
What format do you deliver the map in?
Whatever the project consumes — a marked, photographed, dimensioned site for field use; a CAD (DWG/DXF) utility map for design; or an as-built drawing for the record. The locate data (EM traces, sonde points, GPR confirmations, depths) is the same; the deliverable is built to drop into your workflow rather than force you to re-draw it.
Related EM methods
Active EM Line Locating
Apply a known frequency to a target line and trace only that line — the precise, unambiguous core of electromagnetic locating. Direct connection or signal clamp puts a traceable signal on a specific conductive utility so it stands out from everything else in the ground.
ViewEM + GPR Utility Clearance Survey
The complete pre-dig clearance: passive sweep, active EM tracing of every conductive line, GPR imaging for non-conductive lines and confirmation, sonde tracing for drains, and depths at the dig point. The single survey that makes breaking ground safe — and the everyday private locate done right.
ViewTracer Wire Locating & Installation
Locate plastic mains through their tracer wire — and where there isn't one, advise on installing it. The permanent way to keep non-conductive water, gas, and irrigation lines findable for the life of the asset.
ViewSonde Drain & Duct Tracing
Push a sonde — a small battery transmitter — through a non-metallic pipe, drain, or duct, and trace it from the surface as if it were a metal line. The EM answer for plastic, clay, and concrete lines that carry no signal of their own.
View← EM line locating hub·For contractors & pros·Utility locating applications·GPR services
Depth Estimation & Utility Mapping across BC
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