Scanning Offers In-depth Look at Manhole Condition
In the last decade Subsurface Utility Imaging in Utica, New York, has slowly grown its offerings to include pipe inspection and, most recently, manhole scanning technologies.
The jump from subsurface utility engineering (SUE) to pipeline condition assessment and manhole scanning is not that unthinkable, especially after speaking with Robert H. Korosec, PLS, principal of Subsurface Utility Imaging (SUI). Korosec notes that the company is a sister company to Thew Associates Land Surveyors, which in the early 2000s began getting more requests to accurately depict subsurface utilities as part of the firm’s topographic survey offerings.
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At that point, Thew Associates’ clients, who are typically engineers, started asking if the company could perform camera work or pipe inspection capabilities. This persisted for some time and in 2010, the company created SUI. While the company covers the Northeast and Mid-Atlantic regions, much of its work is in Upstate New York. SUI prides itself on giving its clients high-level, high-quality deliverables.
Offering NASSCO PACP-certified camera inspection services using Envirosight’s Rovver X sewer inspection system, SUI works mostly with engineering firms. It tries to focus its efforts on the more “unique” inspection projects vs. larger and more straight forward pipeline inspection work.
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“We like to work with engineers on unique projects. For example, in Port Chester, New York, just outside New York City, there is a storm drain that is about 3,000 ft long and it’s like a big box culvert,” Korosec says. “They wanted to inspect the entire line, but the bottom is bedrock, so there is no smooth bottom, making it very irregular. We inspected the entire line and every manhole was scanned. We used our crawler camera that could traverse rough terrain and we had to walk up through there.”
With an eye on the more interesting and unique projects and looking at projects more from an engineer’s perspective rather than a contractor, the addition of manhole scanning should not come as a surprise. Knowing that many municipal inflow and infiltration (I&I) issues can be traced to manholes, Korosec was doing his research on adding manhole inspection services, when an opportunity to test Envirosight’s then-new CleverScan system arose. SUI completed about 200 manhole scans and made the decision to purchase the system in 2017.
“We purchased our CleverScan system in 2017 because we secured a contract with an engineering firm that we had worked with in the past. Their contract required a standard Level 2 manhole inspection with digital cameras and camcorders,” Korosec says. “When we secured the contract, we brought it to their attention that we had a scanner. They were aware of the technology but were nervous about the price increase. We asked if we could leave our price where it was and use the scanner. They agreed to trying it.”
The result, SUI was able to complete the work more quickly at a reduced in-field labor cost. Korosec acknowledges that there was more time in the office working on the data, but the end-result was a higher quality report that offers a lay flat view of the entire manhole.
“Engineering firms want to see this data,” Korosec says. “Engineers want to see everything and that is what they get with a manhole scanner.”
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The big difference between traditional manhole inspection and manhole scanning is the final product. The engineer can see the entire manhole in one flat image, so the engineer can come up with their own analysis of the condition of the manhole, Korosec notes. The other option, he says, is gathering images and videos with a digital camera from the surface or entering the manhole itself. With the latter, the inspector snaps some photos of the wall from varying distances and varying lighting. The outcomes are generally small photos of varying qualities and it is easy to miss something. The traditional method also is more time-consuming in the field.
In the field, the SUI crews have a form to complete regarding physical measurements including cover diameter, surface, widths and cover to ground elevation. Basically all of the data not included in the scan itself. If there is something that needs immediate attention, they will notify the client immediately before starting the scan.
“The CleverScan software integrates well with our WinCan software, which we use for our final reports. There is a fair amount of office time to create that final deliverable, but it’s a more thorough product and will answer all of the questions an engineer has regarding the manhole’s condition from top to bottom,”
Korosec says. “With CleverScan, the [scanner’s] software is free, and we can provide that raw scan data to the client and they can look at the data themselves as we see it. And a municipality can incorporate that data into their GIS database. It’s a great selling point.”
While the final product is more thorough, there is one major stumbling block to widespread adoption of manhole scanning. According to Korosec — with manhole scanning in particular — municipalities and engineers are not requesting this work. But this is slowly changing.
SUI has a client that works near New York City that sees the value in manhole inspections and the data that a manhole scanner can provide, and after slow to start, they are starting to add manhole scanning requirements to all of their specifications.
“It’s not that they aren’t aware of the problems. They are aware of the role I&I plays, but a lot of municipalities don’t have the funding available to be proactive, so they are being forced into I&I studies,” Korosec says. That is why it is important to educate engineers about the value of manhole scanning data. “As municipalities are exceeding their discharge permits at the treatment plant, they are being forced by the local environmental regulator to look at why they are exceeding those discharge permits. It’s at that point where the municipality finds the funding for I&I studies.”
In conversations Korosec has had with engineers and the municipalities directly, many can tell you where the problem spots are. They might not know why, but they have a general idea of where the I&I issues are occurring. Unfortunately, it is a lack of funding and manpower as to why they are not being addressed.
“Manhole scanning is not being required, and it is a funding issue. They don’t have a lot of extra money to do preventative work,” he says. “Usually it’s that they know they will repave certain streets so they’ll add a couple thousand feet of pipe and manhole inspections or they have a problem and they need us to come out and tell them what the problem is.”
SUI sees this all over New York, unless the client is closer to New York City and the Tri-State area. There, it has gained a fair amount of traction and SUI will see it in a bid — the request for manhole scanning. However, when it comes to Upstate and Southern Tier New York, it’s almost non-existent. SUI finds that it needs to educate the clients that the technology exists.
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In some cases, that education not only includes the idea of manhole scanning, but also manhole inspections in general, as well as the importance of having an overall NASSCO certified inspection program. The latter, Korosec says is across the board with PACP, MACP and LACP.
“We need to get engineers to better understand the certification programs and standardization, and then we will see more opportunities for manhole scanning being added to specifications,” he says. “It needs to migrate to our area and engineers need to see it, understand it and see the value in it. I know NASSCO is getting out there in front of the ASCE boards, so engineers know about it and are becoming more familiar.”