GPR scanning for buried utilities, PVC pipe, tanks and voids, and for rebar and post-tension cable in concrete, across DE, PA, NJ, MD, DC and Northern Virginia.
Ground penetrating radar (GPR) sends short pulses of radio energy into the ground or into concrete and records what bounces back. Pipes, conduit, rebar, tanks and voids reflect the signal differently from the soil or concrete around them, so they show up on screen as distinct curves. A trained technician reads those curves to mark each target's position and approximate depth on the surface. GPR finds plastic, clay and concrete pipe that electromagnetic locators cannot trace, and it uses no radiation.
Trinity Subsurface runs GPR every day in two ways: to locate underground utilities before digging, and to scan concrete before coring or cutting. Crews work across Delaware, Pennsylvania, New Jersey, Maryland, Washington DC and Northern Virginia, and travel for larger projects. Call (302) 407-3697.
We pair the Proceq GS8000 GPR with Radiodetection RD8200 electromagnetic locators. EM traces metallic lines and tracer wire end to end. GPR fills the gaps: PVC and HDPE water and gas service lines, clay and concrete sewer and storm pipe, duct banks, abandoned lines and underground storage tanks. Every locate is marked in paint and flags in the APWA color code, and a field sketch follows within 24 hours. See private utility locating.
For slabs, walls, decks and columns we use the Proceq GP8000 and GP8800 concrete GPR, plus the Pundit PD8050 ultrasonic array where heavy reinforcement limits radar. Technicians mark rebar, post-tension tendons, conduit and voids before you core, saw cut or anchor, and can map rebar spacing and depth for an engineer. See concrete scanning.
GPR depth and clarity depend on the ground. Wet clay, saturated or salty soil, and heavy fill shorten how deep it can see. Small or deep pipes, congested corridors and reinforced pavement can hide targets. Depths from GPR are estimates. When a line runs close to a planned excavation, the reliable next step is a vacuum excavation test hole to expose it and measure it. Read more about what GPR and EM can miss.
EM is fast and precise on metallic lines and anything with tracer wire, and it can follow a line a long way. GPR sees non-metallic pipe and objects with no signal on them, but covers ground more slowly and reads depth less precisely. We use both on almost every locate.
X-ray needs access to both sides of a slab and clearing the area for radiation safety. GPR works from one side, uses no radiation, and marks results on the surface the same day, so hospitals, labs and offices can stay occupied.
On design projects, GPR and EM designating is the core of ASCE 38 Quality Level B. In Delaware, Pennsylvania and Maryland, Trinity delivers QL-B and QL-A investigations led by Greg Finkle, P.E., with utilities mapped in CAD or GIS. See subsurface utility engineering and utility mapping.
Quality Level B designating across the new arena site, plus a GPR search for pile caps left from the previous structure.
Multi-week concrete scanning inside the arena with crews of up to three technicians a day.
Phased concrete scans of double-tee supports, spandrel connections and footing dowels ahead of new pile caps.
Roughly 5,000 to 6,000 square feet of slab-on-grade scanned for Whiting-Turner before saw cutting for new sanitary lines.
GPR wall scanning at 16 locations, three reached by man-lift, so the college could core conduit pathways for a fire alarm upgrade.
It depends on the soil. Dry, sandy ground lets radar see much deeper than wet clay, which is common across the Mid-Atlantic. In concrete, GPR reads most reliably in the top 12 to 18 inches. We note any depth limits on the field sketch rather than guess.
Often, yes. GPR detects the pipe itself rather than a signal on it, so it can find PVC, HDPE and clay lines that EM locators miss. Pipe size, depth and soil moisture all affect the result.
Yes. GPR uses low-power radio waves, not radiation, so nobody has to clear the area and work happens during normal hours.
Marks on the ground or slab in standard colors, a field sketch within 24 hours, and CAD, GIS or KMZ files on request.
Most requests are on site within three business days, often sooner. Call (302) 407-3697 or schedule a crew.
