FAQs

Utility location services, such as those provided by Ground Scan NZ, are essential for anyone planning excavation, construction, or landscaping work. These services accurately detect and map underground utilities—including gas, water, power, and telecommunications—before digging begins, helping to prevent costly and dangerous damage.

Using advanced technology like ground-penetrating radar (GPR) and electromagnetic locators, Ground Scan NZ provides precise, non-invasive detection of both metallic and non-metallic utilities. This is especially important in areas with outdated or incomplete utility records.

Choosing a trusted provider like Ground Scan NZ helps ensure compliance with health and safety regulations, avoids project delays, and reduces the risk of utility strikes, which can result in injury, legal liability, and expensive repairs. Whether you’re a homeowner, contractor, or engineer, engaging a professional utility locating service is a smart investment in the safety, efficiency, and success of your project.

Electro-Magnetic Induction (EMI)—also known as Electro-Magnetic Location (EML)—is a widely used method for detecting underground utilities. It works by transmitting an electromagnetic signal through conductive materials such as metal pipes or cables. A receiver then detects this signal, allowing the operator to trace the utility’s path and depth without the need for excavation.

This technique is particularly effective for locating metallic services like power, gas, and water lines. It can be used in both passive and active modes, depending on whether the utility is already carrying a signal or needs one applied externally. However, EMI cannot detect non-metallic utilities unless they contain a tracer wire.

Ground Scan NZ uses EML as part of its professional utility locating services, often alongside Ground-Penetrating Radar (GPR), to provide accurate and comprehensive mapping of underground infrastructure. By combining these technologies, Ground Scan NZ ensures safe, efficient, and reliable detection for construction, maintenance, and excavation projects.

For more details check out our Utility Location Services page. 

Ground Penetrating Radar (GPR) is a non-invasive geophysical method used to detect and map objects beneath the ground’s surface. It works by sending high-frequency radio waves into the ground; when these waves encounter a buried object or a change in material (such as soil to concrete), they bounce back to the surface. A receiver then records these reflections to create an image or profile of what lies below.

GPR is highly effective for locating both metallic and non-metallic utilities—such as plastic water pipes, concrete storm drains, and fiber optic cables—which may not be detected by other methods like Electro-Magnetic Location (EML). It can also identify voids, buried structures, and changes in ground composition.

Ground Scan NZ uses GPR as a key part of its utility locating services. By combining GPR with other advanced technologies, Ground Scan NZ delivers accurate and detailed underground mapping, helping clients dig safely, avoid costly mistakes, and comply with safety regulations.

For more details check out our Utility Location Services page. 

Multi-Channel (3D) Ground Penetrating Radar (GPR) is an advanced subsurface mapping technology that uses multiple radar antennas simultaneously to collect high-resolution data across a wide area. Unlike standard single-channel GPR, which captures data along a single line, multi-channel GPR collects data in a grid pattern, enabling the creation of detailed 3D models of underground features.

This technology allows for faster scanning and much greater accuracy in detecting and visualizing buried utilities, voids, and other subsurface structures. The resulting 3D images provide clear insights into depth, position, and spatial relationships between different underground elements.

Ground Scan NZ uses multi-channel (3D) GPR for complex projects that require a high level of detail and precision. This is particularly valuable in urban environments, construction zones, and infrastructure planning, where accurate underground data is critical. With 3D GPR, Ground Scan NZ delivers faster results, reduced risk, and enhanced confidence in excavation and design decision

Ground Scan NZ is a professional utility locating company based in the Waikato region, providing expert services across the entire North Island of New Zealand. While centrally located to serve clients efficiently within the Waikato, Ground Scan NZ regularly travels to all surrounding areas—including Auckland, Bay of Plenty, Taranaki, Hawke’s Bay, Manawatū-Whanganui, and Wellington.

Their mobile and flexible approach means no matter where your project is located on the North Island, you can rely on Ground Scan NZ for accurate, timely, and professional underground utility detection. Whether you’re planning a small residential dig or a large commercial development, the team is equipped to handle projects of all sizes.

By combining advanced technologies such as Ground Penetrating Radar (GPR) and Electro-Magnetic Location (EML), Ground Scan NZ ensures safe and compliant excavation across the region. Their commitment to quality service and safety makes them a trusted partner for clients throughout the North Island.

While there is currently no legal colour code requirements for buried utility surface markings here in NZ, a general convention is used and encouraged by Worksafe as follows:

Here at Ground Scan NZ we also use White paint for general markings such as property/survey boundaries, excavation guides or for marking utilities found before they have been positively identified. 

If you have any questions about any surface markings on your property or job site please do not hesitate to Contact Us. 

A Build-Over Survey is a type of survey conducted to accurately locate and document existing underground utilities—such as sewer lines, stormwater drains, or other services—that lie beneath or near a proposed building or structure. This survey is typically required when construction is planned over or close to public infrastructure, to ensure that the work complies with local council or utility provider regulations.

The main purpose of a Build-Over Survey is to confirm the position, depth, and condition of the affected utility, helping engineers and designers plan foundations and structures accordingly. It also ensures that access to the utility is maintained and that the new construction will not cause damage or disruption.

Ground Scan NZ offers Build-Over Surveys using advanced technologies like Ground Penetrating Radar (GPR), Electro-Magnetic Location (EML) and Pipeline CCTV to provide accurate underground mapping. Their surveys help clients meet regulatory requirements, avoid costly construction issues, and ensure long-term safety and compliance.

An As-Built Plan is a detailed drawing or document that shows the exact locations and specifications of structures and utilities after construction or installation is completed. Unlike design plans, which show the intended layout, an As-Built Plan reflects the actual positioning of features such as underground pipes, cables, conduits, and other infrastructure.

These plans are essential for future maintenance, renovations, or excavations, as they provide accurate information about what’s beneath the surface or within a structure. As-Built Plans help prevent accidental damage during future works and support better decision-making for engineers, contractors, and property owners.

In utility locating, companies like Ground Scan NZ can help create or verify As-Built Plans by using technologies like Ground Penetrating Radar (GPR) and Electro-Magnetic Location (EML) to map underground utilities. This ensures plans are up to date and reliable, even when original records are missing or inaccurate.

A .DWG file is a widely used digital file format for storing two-dimensional (2D) and three-dimensional (3D) design data, primarily created with AutoCAD and other computer-aided design (CAD) software. The term “DWG” stands for “drawing,” and it is the native file format for AutoCAD, one of the most popular CAD programs in the architecture, engineering, and construction industries.

.DWG files contain detailed design information, including geometric data, maps, layers, annotations, and metadata. They are essential for producing accurate construction documents, technical drawings, and As-Built Plans.

For utility locating and surveying work, companies like Ground Scan NZ often deliver results in .DWG format to ensure compatibility with engineers, designers, and contractors’ existing software systems. This allows for seamless integration of underground utility data into wider project plans, helping streamline workflows and reduce errors. The .DWG format is valued for its precision, versatility, and compatibility across a wide range of design applications.

BIM Modelling (Building Information Modelling) is a digital process used to create highly detailed, data-rich 3D models of buildings and infrastructure. Unlike traditional 2D drawings, BIM models include not just the visual representation of a structure, but also detailed information about materials, dimensions, systems (like plumbing and electrical), timelines, and more.

BIM is used throughout a project’s lifecycle—from planning and design through to construction and ongoing maintenance. It improves collaboration among architects, engineers, contractors, and facility managers by providing a central, up-to-date model that everyone can access.

In utility locating, companies like Ground Scan NZ contribute to BIM workflows by providing accurate underground service data that can be integrated into the model. This ensures the BIM reflects real-world conditions, helping prevent clashes, reduce rework, and improve construction efficiency. By incorporating verified utility locations into BIM models, projects are safer, more cost-effective, and better planned.

Acoustic Leak Detection is a method used to identify leaks in underground pipes, particularly water and gas lines, by listening for the sound of escaping fluid or gas. Specialized sensors and microphones are placed on the ground or attached to pipes, capturing the faint noises produced by leaks, such as hissing or dripping sounds.

This non-invasive technique allows technicians to pinpoint leaks without digging, minimizing disruption and reducing repair costs. Acoustic leak detection is especially useful for detecting small leaks that may not be visible but can lead to significant water loss or safety hazards if left unattended.

Companies like Ground Scan NZ use acoustic leak detection as part of their comprehensive utility locating services, helping clients quickly find and address leaks before they cause damage or waste resources. This method supports efficient maintenance, prevents costly repairs, and contributes to sustainable water and energy management.