Case Study: Utilizing Manhole Scanning Technology for Manhole Inspections

    SUI was retained by the Village of Rye Brook (Village) to clean and CCTV inspect 10,000 feet of sanitary sewer conveyance piping, perform 50,000 feet of smoke testing, and inspect 236 manholes in support of an infiltration and inflow (I&I) investigation of a portion of the Village’s wastewater infrastructure.

    Although the project specifications did not require the use of a manhole scanner to accomplish the manhole inspections, SUI elected to utilize a CleverScan manhole scanner to capture a 360 degree view of the interior of each manhole in lieu of a digital camera or video recorder mounted on a pole and advanced down each manhole.

    The Clever Scan device was situated over each manhole opening and advanced down the interior of the manhole while capturing colored digital photographs and laser measurements. Once the scan was complete, the image was viewed on a laptop computer to verify the quality of the imagery. If required, the CleverScan was deployed for a second to re-capture colored imagery.

    Each scan was accomplished in under five minutes and on average, scan data was collected on 50 manholes in an eight hour day.

    In an office environment, each scan was imported into WinCanVX pipeline inspection software for subsequent defect coding in accordance with NASSCO MACP, Level 2, protocol. A manhole inspection report was generated in WinCanVX and final deliverables included the manhole inspection report, scan files, and digital photographs.

    Utilizing the CleverScan device greatly reduced the amount of time required at each manhole, which reduced the exposure of field technicians and vehicular traffic, and provided high definition three-dimensional imagery of the manhole interior. It is anticipated that the field time was reduced by 60% compared to conventional manhole inspection devices (e.g. digital cameras or video recorders) while providing a higher quality deliverable.

    To learn more about our manhole scanning capabilities, please contact Cameron Wattles at

    Read more

    Ground Penetrating Radar: How deep can you see?

    One of the most common questions we field when someone is inquiring about the capabilities of GPR is “how deep can you see with the technology?” This question does not have a one size fits all answer. Many factors contribute to the effectiveness of GPR and soil conditions play the largest role. In general, dry sandy soils lend well to GPR while clay-based soils with high moisture content can be very difficult for GPR penetration. In some situations, depth penetration may be limited to a few feet or less within clays, whereas targets residing in sandy soils could be detected at depths up to 8 feet.

    Another factor which dictates the depth of returns for GPR is the antenna frequency being used. Lower frequency antennas will generally penetrate deeper, with a loss of resolution of the upper stratigraphy, and high frequency antennas will penetrate less, but provides higher resolution.

    In general, multiple factors need to be analyzed when answering the “how deep can you see” question. Ground composition, anticipated depth, size, and material of a feature all need to be considered when analyzing the effectiveness of GPR.

    To learn more about ground penetrating radar technology and our geophysical services, contact Cameron Wattles at

    Read more

    Three members of SUI staff obtain PACP certification

    Subsurface Utility Imaging, LLC is excited to announce the recent completion and certification of the NASSCO (National Association of Sewer Service Companies) PACP (Pipeline Assessment Certification Program), LACP (Lateral Assessment Certification Program), and MACP (Manhole Assessment Certification Program) by three of its staff members.

    NASSCO’s PACP, LACP, and MACP programs provide industry deficient coding standards and forms when performing pipeline, lateral, and manhole inspections utilizing Closed Circuit Television (CCTV) and certified PACP software. This standardization allows end users (municipalities, engineers, GIS specialists) to quickly review and interpolate inspection reports to determine the conditions of sanitary and storm mainlines, laterals, and manholes.

    Read more