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Start with the latest utility drawings, as-built records and the proposed excavation limits. Identify the decisions the survey must support and note areas where records are incomplete or conflicting.

A GPR or complementary locating survey can provide additional evidence of possible buried features. Detection depends on target properties, ground conditions and site access; not every service will be visible.

Use the results with the project’s permit and safe excavation procedures. Confirm critical locations by an appropriate approved method before intrusive work.

Ground Penetrating Radar uses electromagnetic waves and is commonly used to investigate near-surface features, including utilities and concrete reinforcement where conditions permit.

Electrical Resistivity Tomography measures variations in electrical resistivity and can support interpretation of ground, geological and groundwater conditions. Resistivity values are not unique identifiers of a material.

Share the target, expected depth and available site information with the survey team. GPR and ERT can sometimes provide complementary evidence, while direct investigation may still be needed.

Provide site boundaries, access instructions, relevant drawings and the location of existing hazards before mobilisation. Agree on the area to be investigated and any working-hour restrictions.

Clear accessible survey lines where feasible and identify areas restricted by traffic, vegetation, metal surfaces or overhead activity. Arrange a site contact who can coordinate permits and access.

Discuss expected deliverables and any necessary follow-up before work starts. Some obstructions or ground conditions may limit coverage, so record these in the final interpretation.

The report should describe the project objective, location, methods, survey coverage and field conditions. A map or plan should show where data was collected and where access was restricted.

Results may include interpreted plans, profiles or observations, with a clear explanation of what the data can and cannot show. Coordinate systems and assumptions should be stated.

Before relying on a finding, agree how it will be checked against other records or confirmed in the field. Request deliverables in the formats your design and project teams need.

Before drilling or cutting, identify the work area, element type and available structural drawings. Define which features are important to locate and how much surface access is available.

GPR can help identify reinforcement and other detectable features under suitable conditions. The ability to resolve a feature depends on depth, spacing, material and the equipment configuration.

Mark and document the investigation area and communicate uncertainties to the structural engineer and contractor. Do not treat a scan as a guarantee that all hazards have been detected.

Begin with the project objective: water-resource assessment, site investigation or another defined question. Review geological maps, borehole records and existing groundwater data where available.

Geophysical methods such as resistivity can help identify subsurface variations that may be relevant to groundwater interpretation. Similar resistivity responses can have different geological causes.

Use findings to guide the next phase of investigation, such as targeted boreholes or sampling where appropriate. The final scope depends on the site and should be agreed with qualified specialists.

GPR transmits electromagnetic energy and records reflections from contrasts in materials. Its performance depends on the target, antenna, ground and survey setup.

Electrical conductivity and moisture can reduce penetration, while dense reinforcement, surface obstructions and complex ground conditions can make interpretation more difficult. Depth and resolution involve practical trade-offs.

A site review and, where useful, a trial survey can help assess suitability. Communicate expected coverage and limitations before decisions are made from the results.

Agree on the coordinate reference system, survey limits and required deliverable formats at the beginning. This allows field observations to be compared consistently with project drawings and maps.

GIS can bring together investigation locations, interpreted features and other relevant layers. Each layer should retain its source, date and appropriate level of accuracy.

Use clear symbology and metadata to help teams distinguish observed data from interpreted features. Keep the original survey records available for review and future updates.

Define whether the project is concerned with pavement features, buried infrastructure, ground conditions or a combination of objectives. Review existing corridor drawings and access restrictions.

Survey methods and coverage should be selected for the target and local conditions. Work with the project team to plan safe access and any traffic management required by the site.

Present results against a consistent project alignment and coordinate system, and record gaps in coverage. Follow-up testing may be needed to verify interpretations.

What decision will the survey support, and what targets or conditions are you looking for? Where is the area of interest, and what depth and coverage are needed?

What drawings, site history and access information are available? Which conditions could limit a method, and what complementary checks might be required?

What outputs does your team need—for example, plans, profiles, a technical report or GIS/CAD files? Agree the scope and verification approach with the survey provider before work begins.