On this episode of the Pipeliners Podcast, Pete Weber of DoC Mapping joins Russel Treat to discuss how operators determine depth of cover for pipelines at water crossings and why it matters for integrity and risk management. The conversation explores regulatory expectations, historical and modern inspection practices, and emerging technologies that improve accuracy in underwater pipeline surveys. The discussion also highlights the importance of understanding environmental conditions, data limitations, and real-world risk factors. Listen now to learn more about the evolving approaches to assessing and managing pipeline water crossings.

Identifying Depth of Cover for Pipelines Crossing Waterways Show Notes, Links, and Insider Terms

• Pete Weber is the Chief Operating Officer at DoC Mapping. Connect with Pete on LinkedIn.
  • DoC Mapping LLC provides advanced pipeline and cable locating services using innovative multi-sensor and GPS-integrated technologies to deliver fast, accurate, and detailed depth-of-cover data for operators across North America.
• API (American Petroleum Institute): Since its formation in 1919 as a standards-setting organization, API has developed more than 700 standards to enhance industry operations. Today, it is the global leader in convening subject matter experts to establish, maintain, and distribute consensus standards for the oil and natural gas industry.
  • API RP 1133 is a recommended practice that provides risk-based guidance for managing hydro-technical hazards at onshore and coastal pipeline water crossings—including inspection, monitoring, mitigation, and integrity management—to prevent loss of cover (scour) and protect public safety and the environment.
• PHMSA (Pipeline and Hazardous Materials Safety Administration) is responsible for providing pipeline safety oversight through regulatory rule-making, NTSB recommendations, and other important functions to protect people and the environment through the safe transportation of energy and other hazardous materials.
• Depth of Cover (DoC) is the vertical distance between the top of a buried pipeline and the ground or riverbed above it, used to determine pipeline exposure risk.
• Pipeline Crossing is any location where a pipeline intersects a waterway such as a creek, river, or channel and therefore requires specialized inspection and monitoring.
• Underwater Utility Locating is the process of identifying and mapping the position of pipelines or utilities beneath water using remote sensing tools.
• Commercial Diving is the professional, physically demanding practice of diving to perform underwater inspections, construction, or pipeline assessment work.
• ROV (Remotely Operated Vehicle) is an unmanned, tethered underwater robot used for remote inspection or access to submerged pipelines or structures.
• Internal Pipe Inspection Robots are devices that move through the inside of a pipeline to analyze its condition, detect defects, and support integrity management activities.
• Navigable River Crossing is a pipeline segment that crosses any waterway capable of supporting boat travel—often defined broadly and requiring regulatory inspection.
• Exposed Pipe is any section of pipeline no longer buried due to erosion, scour, or channel movement, increasing the risk of physical damage.
• Bathymetry is the measurement and mapping of underwater terrain and depth to understand the pipeline’s surrounding environment.
• Scour is the erosion or removal of sediment around a pipeline or structure caused by water movement, a primary mechanism of pipeline exposure.
• Vortex-Induced Vibration (VIV) is vibration caused by cyclic water-flow forces acting on a pipe, which can lead to fatigue or structural damage.
• Third-Party Damage is pipeline damage caused by external activities such as anchoring, dredging, vessel operations, or construction.
• 100-Year Flood / 500-Year Flood is a statistical estimate of extreme flood events used in pipeline risk modeling to predict conditions that could expose or damage pipelines.
• Hydro-Hazard Community is the group of specialists focused on water-driven hazards—like erosion, flooding, and scour—that affect pipeline integrity.
• Remote Sensing (Electromagnetics) is a non-invasive technology that uses magnetic field measurements to determine pipeline position in three dimensions.
• Three-Axis Magnetometer is a sensor that measures magnetic field strength in three dimensions, allowing detection and vector calculation of pipeline-related anomalies.
• Gradiometer is a device that measures differences in magnetic field intensity between two sensors to triangulate the precise location of a pipeline.
• XYZ Positioning is the three-dimensional coordinate system (horizontal and vertical position) used to map pipeline location underwater.
• Sonar is acoustic imaging technology used to map the riverbed and determine the sediment surface above a pipeline.
• Towfish / Towed Sensor System is a submerged device pulled behind a boat to collect magnetic or sonar data near the riverbed for higher accuracy.
• Hull-Mounted System is a configuration where sensors are mounted to the boat hull, used in shallow or turbulent water when towing equipment is impractical.
• Fluid Mud is a soft, semi-liquid sediment layer common in coastal rivers that complicates determining the true bed elevation for depth-of-cover calculations.
• QA/QC (Quality Assurance / Quality Control) is the set of processes for validating the accuracy, precision, and reliability of survey data.
• GIS File (Geographic Information System) is a digital mapping file used by operators to store and assess pipeline locations and compare them with surveyed results.
• Scour Model is a predictive model used to estimate how sediment around a pipeline will erode or shift during various flow or flood conditions.
• Risk Program is a structured framework—required in Canada—designed to assess threats, evaluate risk, and determine inspection intervals for pipeline crossings.
• Drone-Based Surveying is an emerging method using aerial drones to map surface erosion, channel migration, and other features affecting pipeline depth of cover.
• The CRM Rule (Control Room Management Rule as defined by 49 CFR Parts 192 and 195) introduced by PHMSA provides regulations and guidelines for control room managers to safely operate a pipeline. PHMSA’s pipeline safety regulations prescribe safety requirements for controllers, control rooms, and SCADA systems used to remotely monitor and control pipeline operations.
• Control Room Management is regulated by PHMSA under 49 CFR Parts 192 and 195 for the transport of gas and hazardous liquid pipelines, respectively. PHMSA’s pipeline safety regulations prescribe safety requirements for controllers, control rooms, and SCADA systems used to remotely monitor and control pipeline operations.

Identifying Depth of Cover for Pipelines Crossing Waterways Full Episode Transcript

Russel Treat:

Welcome to the “Pipeliners Podcast,” episode 416, sponsored by EnerSys Corporation, providers of POEMS, the Pipeline Operations Excellence Management System, operations and compliance software for pipeline operator to address control room management, safety program management, and field operations. Find out more about POEMS at enersyscorp.com.

[background music]

Announcer:

The Pipeliners Podcast, where professionals, Bubba geeks, and industry insiders share their knowledge and experience about technology, projects, and pipeline operations.

Now your host, Russel Treat.

Russel:

Thanks for listening to the Pipeliners Podcast. I appreciate you taking the time. To show that appreciation, we give away a customized YETI tumbler to one listener each episode. This week, our winner is Drew Franklin with Husky Midstream. Congratulations, Drew, your Yeti’s on its way. To find how you can win this prize, stick around till the end of the episode.

This week, we speak with Pete Weber with DoC Mapping about determining depth of cover for pipelines crossing waterways. Pete, welcome to the Pipeliners Podcast.

Pete Weber: Thanks, Russel. It’s great to be here. I appreciate the opportunity.

Russel: It’s great to have you. I feel like I’m going to learn something new today, so looking forward to this conversation.

Pete: As am I.

Russel: Maybe if you would, to start, tell us a little bit about who you are, your background, and how you got into knowing all about pipeline crossings.

Pete:

Sure. I would start off by saying I’m a generalist more than a specialist. I’ve done a bunch of stuff, but I’m one of the founding members and the COO of DoC Mapping. DoC Mapping is a company that specializes in underwater utility locating, and that’s mostly for pipelines in North America.

I’ve done all sorts of stuff, from ROV-type work, commercial diving work. I’ve been doing underwater inspection stuff since I was 22 when I graduated college.

Russel: How’d you get started in that? Because that’s a fairly unique specialty.

Pete:

It is. I have a geology degree. As I was graduating, I didn’t want to get a real job, so I went to commercial dive school in Southern California. As that, the specialty I took was an underwater inspection specialty.

When I graduated from that, I bounced around, did a little bit of underwater stuff, did some building inspection stuff in the Northwest and the Bay Area, and then refocused on the underwater world.

I worked for a company in San Diego that made parts for ROVs, and then I worked for a company that made robots that go inside and do internal pipe inspection work, and all that culminated in coming up with a better way to do these depth-of-cover surveys that my business partner and I put together, and in 2014, decided we were going to take a shot at just doing that.

Russel: I’ve known some people in my life that were commercial divers, and it’s a very demanding business. It’s a young man’s game because it’s extremely physically demanding. It pays extremely well, but it’s an unforgiving specialty.

Pete:

That it is. If we’re being real honest, I got to the point where I knew enough about it that it scared me.

[laughter]

Pete: I thought, “Well, there’s probably some better ways to make money than this.”

Russel: Yeah. That’s the whole, “I’m 22 and I’m immortal,” versus, “I’m 32 and I have a family” conversation.

Pete: That is exactly correct. I learned a lot, though. I oftentimes tell people that I feel like I learned more real-world usable skills in one year of commercial dive school than I did in four years of university, though.

Russel: I’m sure that’s true because you actually have to learn how to do it versus how to think about it, which is, in college, you learn how to think about it. You’re not learning how to do it, oftentimes.

Pete: Correct. I’m very much a doer.

Russel: Let’s talk a little bit, what are the regulatory requirements around underwater inspection for pipelines? Anybody who’s managing pipeline integrity understands crossings and underwater pipe, but to me, it’s a unique specialization.

Pete: It is. We work in the US and Canada, and the regulations are a little bit different in the two. In the US, both hazardous liquid pipes and natural gas pipes are overseen by PHMSA. It’s this thing called 49 CFR, and it’s Part 195 is for the liquids pipes. I think it might be 192 talks about gas pipes.

Russel: That’s exactly right.

Pete:

They distinguish between the two, acknowledging that they’re both hazardous materials but they’re a little bit different. On the liquids side of it, the regulation essentially just says, “You have to inspect navigable river crossings once every five years.” On the gas side of it, they say, “You have to periodically inspect your navigable river crossings.

The term navigable river crossing has been fairly well-defined now. It’s basically anything that is connected to another body of water that you could put a boat down, which is functionally anything.

Russel: Pretty much.

Pete:

We do surveys that are ankle-deep creeks, seasonal things. It’s functionally anything that’s a creek or a river, really. The spec is very vague. If you go online, you can look at some clarifications. What they’re going for is they want to make sure that the pipe is buried in the river, and if it’s not buried, is there anything hung up on it.

Traditionally, this was done with divers just walking and seeing if the pipe was exposed and then looking to see, if it was exposed, if there was anything hung up on it. That’s what they were doing in the ’70s and ’80s for this kind of stuff. A lot of the gas lines never got inspected in waterways. They might do bathymetry and some sonar work and look.

In Canada, the regulatory structure is much more driven…They mandate that pipeline operators have a risk program so that they understand where the risks are. Then they work with them to determine what type of inspection parameters or intervals or whatever is involved.

In Canada, it’s a little bit more of a system that’s driven by real-world risk. Here, as it sits now, it’s that five-year and then some sort of periodic thing for gas lines.

Russel:

I know a bit about this subject just because some subject matter expert teams I’ve been on and some of the work they were doing. It’s not really my discipline, but I’ve worked with people that do that stuff and worked around them.

The thing that’s interesting to me is that the regulations related to underwater pipeline crossings are pretty sparse.

Pete: Yes.

Russel: Likewise, are there any API or other standards for this?

Pete:

There is an API standard. I can’t remember which one it is, but there’s one that talks about navigable river crossings. As far as I know, it’s not a federal standard. It’s a recommended thing. Having looked at it, it’s fairly vague, too.

I recall that one deals more with scour and vortex-induced vibration, like failure mechanisms, more so than how often should you inspect your pipe. That is more of like what should you be looking for when you inspect it, is my understanding of the two.

Russel: It’s interesting because there have been a couple of incidents. For example, the incident off of Huntington Beach was an underwater pipeline not in navigable waterway. It was offshore in the ocean, but it wasn’t buried. It was just laid on the seafloor and got caught in an anchor drag.

Pete:

That’s very, very common, not just offshore, but in rivers. There was an incident in the Mississippi River where an anchor got dropped on a gas pipe and exploded and killed some guys on a tug.

The reality of it, though, is if your pipeline has six inches of mud on it, it probably doesn’t make a hill of beans difference if someone drops an anchor on it if it’s six inches of mud or exposed though. When you get into the risk space, it’s important to know where your pipe is in a real-world way and then what are the real risk factors that are associated with it.

Russel: That’s so true. If I have exposed pipe in a shallow portion of the Mississippi River, that’s a very different risk than I have pipe laying on the seafloor in 1,000 feet of water.

Pete: Correct, or if you have a spanning pipe that’s in the seasonal creek in northwest Texas that maybe sees water flow once every few years and it’s a 10-foot gully. Just because a pipe’s exposed does not necessarily mean it’s at risk, and just because it’s not exposed doesn’t necessarily mean it’s not at risk.

Russel:

Understanding the potential failure mechanisms and the likelihood of those mechanisms occurring and the consequence of that mechanism occurring, and coming up with ways to manage that risk.

For a lot of navigable crossings, that risk is more about third-party damage than it is about anything else. It depends, I guess, because it’s also about something more significant than normal flow.

Pete:

Absolutely. When you talk about gas pipelines versus petroleum pipelines, the risks associated with those things are very different. If you have a leak in a gas pipeline, you’re probably not doing much environmental damage with that.

If it’s somewhere where you can have an ignition source, your chance of killing someone with that is much higher than if you had a leak in a liquids line that’s going to cause environmental damage but probably is not going to cause some catastrophic loss of life type situation.

Different things cause those. If you had a big liquids line that failed in a river that was upstream of a metropolitan area and you’ve got a big, giant oil slick that goes through a major city, that is a terrible thing environmentally. It’s a terrible thing for the pipeline owner. It’s very difficult to clean up. It’s very expensive.

Russel: Just to wrap this part of our conversation up, it’s really important for operators to understand there’s a difference with water crossings between doing what is required and doing what’s necessary.

Pete: Absolutely. Correct.

Russel: That’s probably one of the areas in pipeline operations where that’s most true, and that risk is very dependent on the circumstances.

Pete: It’s out of sight, out of mind a lot of times. It’s not like you can send your guy, the local guy at the compressor station, to go down there and look at this thing. You can’t see it without having a significant amount of equipment and a boat on the water.

Russel: And expense and all kinds of other stuff.

Pete: Correct. It’s really important when you spend the money to do that inspection, you understand what do I want out of this, and that you can rely on what you’re getting as actual usable data.

Russel: Let’s talk a little bit about historical approaches. You mentioned that historically, what people were looking at is was the pipeline covered, and if it wasn’t covered, was there anything hung up on it.

Pete: Correct.

Russel:

I would also say that that’s certainly been my experience. I would say more recently, people are getting a little bit more elegant. If they’ve got pipe that’s above a waterway, they’ll do some level of analysis of what happens if I get a 100-year flood or a 500-year flood, and what’s my plan if that occurs. They do some risk mitigation.

A lot of times, the plan is shut the pipeline down and turn it off, get the pressure out of it until the event’s over. When you get to the more advanced risk analysis, you really have to understand a lot more than just that.

Pete:

It starts with having, like they say in computer programming, garbage in, garbage out.

If you don’t have good, reliable data that you can apply to models, whether that’s failure mechanics models for exactly…In the hydro hazard community, there’s a fair amount of discussion about what actually causes pipe failures when pipes get exposed and span. That’s not really our thing, but that’s there.

Also, when is the pipe likely to get exposed? If it’s exposed, how much of it’s exposed? Are we really sure it’s exposed? Where is it? Where is it in relation to other things that might be present at that crossing?

Where is it in relation to a bridge that’s upstream, for example, or a groin that’s coming, or a dike that’s coming out into the river and causing a scour feature or something like that? Knowing where those things are makes a big difference when you’re trying to predict what might happen.

Russel: Historically, what we did is we looked at the pipe. Now what we’re doing is we’re looking at the pipe and all of the surrounding environment.

Pete: I would say historically, what we were trying to do is we were trying to say, “OK, the pipe’s buried.” A lot of times, that would involve taking a six-foot probe, sticking it in the mud, and saying, “I didn’t hit the pipe with the six-foot probe, so it must be buried deeper than six feet,” which is flawed logic, but that’s the best you could do.

Russel: It presumes the pipe’s directly underneath where I stuck the pole into the mud.

Pete:

It presumes you know where…You’re not hitting rocks or you’re not hitting riprap. There’s all sorts of problems with that.

We’re moving from being worried about what is the depth of cover to where is the pipe in real-world coordinates, and where is the bottom in real-world coordinates, and where’s the bank in real-world coordinates, so that we can then apply that to larger data sets, weather models, scour models.

There’s all sorts of different ways you can apply different models to reliable real-world data to help inform your risk system.

Russel: Sounds easy if you say it fast.

Pete: [laughs]

Pete: Now my wife is going to get on me because I say that too much. She hears me say that on this podcast because she listens to all of them. Then she says, “Russel, you need to quit saying that,” but it’s very true.

Pete: It is true.

Russel: There’s a lot of information required. You say you recently founded your business. Clearly, you saw a need here. What is your approach to underwater pipeline inspection? What do you guys tend to focus on?

Pete: The bread and butter of what we’re trying to do is we’re doing remote sensing using electromagnetics. Our primary pipe locating system, it’s an array of three-axis gradiometers. We apply…

Russel: Hold on. Stop.

Pete: [laughs]

Pete: You’re assuming I know what a three-axis gradiometer is.

Pete: Got it.

Russel: Let’s talk about what that is first before you go any further.

Pete:

There’s magnetometers that measure magnetic fields. If you take a magnetometer that just measures the entirety of a magnetic field and you break that into a sensor that can measure the magnetic field strength in three dimensions, now you have a three-axis magnetometer.

From that three axes, I can generate a vector because I now have three intensities. I can then generate a vector.

Russel: That way, you know which way the field is pushing or pulling.

Pete: Correct. If I take two of those and put those together and measure the difference between the field strength at this sensor cluster and the field strength at this sensor cluster, that then becomes a gradiometer. It’s a device that measures the difference in magnetic field strength between two locations.

Russel: You said three-dimensional, so you’re doing that in three dimensions.

Pete: We’re doing it in three dimensions.

Russel: Vertical, longitudinal, and horizontal axes.

Pete:

Yeah. The three axes generally are figured like north, south, east, west, and then horizontal, if you think of the axes that way.

I measure the field strength on each of those axes at each sensor. I can generate a vector, and where those vectors cross is the center of the magnetic field, which in theory, is the center of the pipe. That’s the bread and butter of what we’re doing. There’s a whole bunch of stuff.

Russel: That makes sense because a string of metal is going to create a deviation in the magnetic field.

Pete: Correct, and because of the river…

Russel: By measuring those deviations, you basically create pointers, vectors. By knowing, “Here is where the instrument was and here’s the direction here, and here’s where it was and here’s the direction here,” you’re going to say, “Here’s the pipe,” because you’re going to triangulate it.

Pete: Absolutely.

Russel: That makes perfect sense. I get exactly what you’re doing.

Pete:

But the positioning part of it’s really important. We need to know very precisely where those sensors are at any given time. The current sensor, we’re running models at two and a half hertz, so two and a half times a second, I’m pulling a vector out of that system.

If you think about how a pipe crosses a river, it almost always goes perpendicular to the flow of the river, which means…

Russel: It was certainly put in that way.

Pete: We hope so. Some of them are at a little bit of an oblique angle.

Russel: It depends on where they are and what they’re connecting.

Pete: Exactly.

Russel: You use the shortest distance to cross, which is generally a straight line between the two.

Pete: Absolutely, which is good for me because it allows me to drive a boat directly against the current and then directly with the current. I can do that at predetermined intervals, 50-foot spacing or something, and then I can calculate the pipe position from all the vectors generated per pass and find the most accurate, best data point in XYZ because all that stuff is hooked into a…

Russel: You’re not only identifying where it is on the map, but also where it is above or below the ground.

Pete: Correct. Initially, on the locating, all I’m getting is an XYZ position for where the pipe is, and then secondarily, I’m doing work with the sonar to determine where the riverbed is, and then I’m combining those. I’m determining what the depth of cover is by taking…

Russel: You’re basically building a three-dimensional map.

Pete:

I’m building a three-dimensional model of the pipe and the riverbed and putting those together, and then taking a slice of that model and generating a plan and a profile view that’s easy to read and understand.

It’s a three-dimensional model of the riverbed with the pipe crossing it. Then you can use that for all sorts of stuff. You can take that data and put it into a scour model and look at what might happen under 5, 10, 15, 20-year flood.

Russel: How did you come up with this idea? I get the need, but how did you come up with the idea for the approach?

Pete:

This is one of those weird chance things that happens in your life. When I mentioned previously that I worked for a company that made components for ROVs in San Diego, their sister company made utility locators, and they were right next door. I would go have lunch with those guys and talk to them, and I always thought it was interesting.

Then when we were approached by one of our clients at the previous company with a problem like this, I said, “Oh, there’s got to be something out there that will do this, will tell me where this is,” because this particular river that they asked us about, it was basically in a rapid in a river in the West.

There was no holding station. You couldn’t see anything. They thought the pipe might be exposed, but they weren’t sure.

Russel: The idea of trying to dive something like that, it’s really complicated.

Pete: There was no diving.

Russel: Particularly if you’re using hoses or anything like that, gets real complicated real quick.

Pete:

The water was really swift. Long story short, what we ended up doing is taking one of the utility locators that that sister company made and hacked it to output the data real-time and time sync it with GPS data so that we could analyze the field in post. It was a very clunky manual process, but it worked.

Then the regulatory body that was in charge of that crossing said, “That’s great. Really good job on this. Now you have to do this on the rest of your crossings.”

Russel: [laughs]

Russel:

We spent the next three or four years refining the process and partnered with another company that specialized in doing sensors. They just started building sensors that were locate sensors that were GPS-tied. We were able to lean on them and bring some of their systems in. That saved us from the R&D.

Now we’re in the phase where we’re developing the next generation of those systems based on sensors that are much more sensitive and much more low-cost than what’s planned.

Russel: Do you actually have to have the sensor in the water, or can you have it out of the water?

Pete:

You can have it out of the water, but at the end of the day, if you’re modeling magnetic fields, the closer you can get your sensor array to the center of the field, the better the data is going to be.

If I’m in the Mississippi River and I can put a towfish at the bottom of the Mississippi River that’s 50 feet down, I’m going to get way better data than I’m going to get if I have it on a boat that might be 60 feet away from the pipe.

Russel: What if you’re in a narrow rapid and you’re trying to locate? In that case, it might make sense to have the sensor out of the water.

Pete:

You have it on the boat. We have hull-mounted systems, and we have tow systems, both. You’re right. If the water is deeper than, say, 10 feet deep, we usually try to do a towed system. If it’s shallower than that, you can get away with a hull-mounted system.

A hull-mounted system, there’s one whole level of complexity that comes out because now I don’t have to do all the positioning for a toolkit that’s dragging behind. You’re correct. In that scenario we talked about, where it was in the rapid, we just mounted the sensor on the hull of a raft and then pulled the raft around inside the rapid and mapped where the pipe was going. It was very clunky.

Russel: I’m just thinking, if somebody was walking the river and saw you guys out there doing that, thinking, “What are those knuckleheads doing?”

Pete: What are they up to?” It probably took us a month to post-process that data set. Now we have proprietary stuff that I could do that survey and post-process that data set in probably four hours. [laughs]

Russel: That’s the way technology evolves. What would you say some of the key lessons you learned have been in the process of developing this and deploying this technology?

Pete: Gosh. There’s a lot of different aspects to this. Probably the biggest lesson that I would like to convey to people doing this is it’s important to understand where the error lies and what’s important in an error space, an accuracy space, what matters and what doesn’t matter. How do you make decisions based on that? I’ll give you an…

Russel: Before you dig in, I’m visualizing this in my mind. I want to press in a little bit because you bring up something that’s really interesting to me. Is there a distinction between a muddy bottom and a rock bottom when looking at depth of cover? Does that impact this error space consideration you’re talking about?

Pete: Yes. One of the things — and it happens a lot down here on the Gulf Coast — is there’s this stuff called fluid mud. You wind up with this fluid mud that’s at the bottom of rivers and shipping channels and stuff. You have to just decide what your criteria is for the bottom.

Russel: It goes from dirty water…

Pete: You go from chocolate milk, to pudding, to cake. [laughs]

Russel: to muddy water, to watery mud, to cakey mud, to clay, to something hard. That interface can be 10, 15 feet.

Pete:

It could be. We’ve done a bunch of fluid mud studies around Houston and in the Sabine River. There’s some guys that are working on that. That’s an important one. You have to understand, on the sonar side, where is my sonar return coming from?

What density of material am I getting enough of a return on that it’s calling that the bottom? Are we OK with that? Is that invisible? Is that invisible in the data? Are we just saying that’s the bottom, or do we know? I don’t know.

We get into a lot of situations where people will come out with a spec for a crossing. They will, for example, say, “You have to do a calibration on the sonar to make sure it’s accurate to one centimeter,” or, “The GPSs have to be accurate to two centimeters horizontally and three centimeters vertically.”

That’s great. I’m all for driving precision wherever we can, but in the grand scheme of things, when I’m doing remote sensing on a pipe and I might have a plus/minus two-foot confidence level on a locate is a three-centimeter versus a two-centimeter variance on the GPS.

Do you want to pay for that? If you do, it’s fine. I can go through all that and make sure that that happens and do all the QA/QC stuff to make sure that we fall in the spec, but in the grand scheme of things, does it matter?

Russel: Precision versus accuracy.

Pete: Absolutely.

Russel: Cost of data versus usefulness of data.

Pete:

Correct. We see that a lot in specs. Particularly around dredging projects, there tends to be a lot of specs that say, “Your pipe locating needs to be accurate to X,” as a blanket statement for everything. We’re remote-sensing. I argue with people about this all the time. I can’t promise you that.

I generally tell people, “I promise you it won’t be that accurate. I promise you no one else…If you want it that accurate, you’re going to have to dig the pipe up and put a measuring tape on it.” That’s probably the biggest lesson. From a technical side, I would say [inaudible] .

Russel: Said another way, it’s setting the expectations in the user of the data about what this data means.

Pete: Correct.

Russel: If I send you a set of drawings or a GIS file or whatever and it says, “The pipe’s right here,” and it says plus or minus whatever, the danger is people go and read that drawing down the road and they’re like, “That pipe’s right here.”

Pete:

What’s really common in locating is blanket percentage accuracy statements where they say, “Between and 15 feet, this locate data is accurate to five percent of the burial depth. Beyond 15 feet, it’s accurate to 10 percent of the burial depth,” which is 100 percent not true.

Our system, we actually calculate a 95 percent confidence level based on the statistics of the sensor data we’re getting, and we report that. We put that on every report. Every data point has its vertical and horizontal 95 percent confidence measurement.

Sometimes it’s much better than five percent of the depth. Sometimes it’s much worse. It all depends on what’s going on around there, the quality of the signal that you can get on the pipe, how deep the pipe is. There’s a lot of factors, when you start doing this stuff in the real world, that get lost when you start having blanket statements that cover all scenarios.

Russel: Without a doubt. You’re making some really good points. We’ve covered a lot of what I…I wanted to wrap the conversation up. What I’d like to ask is just in general about this technology and approach, what should pipeline operators know?

Pete:

I would say that technology is advancing. We and others are actively working on trying to implement advances in sensor technology and drive down costs, drive up accuracy. If you’re talking to people in this space…We’re really fortunate. There’s actually a couple other folks out there that do a good job of these types of surveys now.

There was a while there where we were looking at historic surveys that were literally a line drawn on graph paper kind of stuff, so it’s getting better.

It’s important that people understand fundamentally what we’re doing. If someone comes and starts telling you about how they have this thing that can do whatever but they won’t tell you in a way that you can understand it, at the end of the day, this is not that complicated. There’s tons of nuance, but it’s understandable stuff.

Russel: You explained earlier in our conversation how it works, and I can visualize that. My mind goes to “I could build one of those. Give me five years and $5 million, I could build it.” [laughs]

Pete: Absolutely. Like I said, it’s not terribly complicated.

Russel: You’re selling tools to engineers. Engineers want to know how things work. They want to understand what are the strengths, weaknesses, and limitations of the tech they’re choosing because they’re going to make other decisions based on that.

Pete: Our tagline is “Transparent, verifiable, repeatable results.” You should understand what the accuracy is and what we’re doing. We should be able to go back and recreate the survey. If you dig that pipe up, it should tell the same story.

Russel:

Look, Pete, this has been a great conversation. I could probably sit here and talk to you for another half hour and still not get all my questions answered, so we probably need to do this again.

For the listeners, this is Pete Weber. He’s with DoC Mapping. That’s for depth of cover. I thought that was dock mapping when I read it the first time, but it’s not. It’s depth-of-cover mapping. We’re going to link up his information on the website. That’s pipelinepodcastnetwork.com. Just go look for episode 416 of the Pipeliners Podcast, and you’ll find all his information.

We’ll put some other resources and such on some links on that page so you guys can find out a little bit more about this tech and the kind of stuff Pete’s doing. Sounds really cool. I have one last question before we leave. Can I find depth of cover if it’s not under water using your tech?

Pete:

You can. We do that sometimes, but there’s, frankly, less expensive people that will do that.

[laughter]

Russel: Until you fully optimize your tools, right?

Pete: Until we fully optimize it. We’re working on some drone-based stuff that I think will be pretty cool, so maybe next time we can talk about that.

Russel: See, now that’s fascinating to me. Particularly if you start talking about the full survey of a crossing and you’re looking at erosion as the river channel moves and all that, what’s my real depth of cover and putting that all together, that’s pretty compelling.

Pete: You interviewed Jeff Barry earlier in the year from Geomorphic Solutions, and he does a really great job. It would be fun to have a discussion, get him on it.

Russel: We ought to get both of you guys together and talk about what a real program ought to look like because he wasn’t talking about what you’re doing, but what you’re doing would feed into all of what he does.

Pete: Absolutely. He’s a real smart guy.

Russel: Interesting. There you go. That’s the wonderful thing about pipelining. Somebody’s always coming up with something newer, better. I’m never going to run out of things to talk about.

Pete: Awesome.

Russel: Hey, Pete, thanks for your time, man. Great to talk to you.

Pete: I appreciate it, Russel. I appreciate what you do.

Russel:

Hope you enjoyed this week’s episode of the Pipeliners Podcast and our conversation with Pete. Just a reminder, you should register to win our customized Pipeliners Podcast Yeti tumbler. Visit pipelinepodcastnetwork.com/win and enter yourself in the drawing.

If you’d like to support the podcast, why don’t you leave us a review? You can do that on Apple Podcasts or wherever you happen to listen. You can find instructions at pipelinepodcastnetwork.com.

[background music]

Russel:

If you have ideas, questions, or topics you’d be interested in, please let me know on the Contact Us page at pipelinepodcastnetwork.com or reach out to me on LinkedIn. Thanks for listening. I’ll talk to you next week.

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