Why Mobile GIS is Critical in Cross Bore Detection and Mitigation

Cross bores occur when a natural gas line is accidentally drilled through existing underground infrastructure - like a sewer pipe. They're a big problem for utilities and a direct risk to public health because of their role in natural gas explosions.

However, new mapping technology - Mobile Geographic Information Systems (GIS) - can help reduce the risks of cross bores by decreasing costs and increasing speed in utility integrity management.

Interested in other applications of Mobile GIS? Learn how this mapping software is streamlining work across industries.

The Cross Bore Problem in the US

In August 1976, Cletus and David Weston, a father and son from Kenosha, Wisconsin, were killed in their home by a natural gas explosion.

Surprisingly, the house lacked gas service, a fact that initially puzzled investigators. It was eventually discovered that a plumber had ruptured a gas line with a pipe auger while trying to unblock the home’s sewer lateral. Gas from the ruptured line had filled the home and ignited, causing an explosion that killed Cletus and David, and injured four others.

This tragic accident surfaced a lethal threat to homes and businesses across the United States: gas line cross bores.

Utility companies suddenly had a massive problem on their hands. The trenchless technology used to quickly and easily install new gas lines had created an immeasurable number of ticking time bombs throughout America’s infrastructure.

This realization gave birth to Cross Bore Detection and Mitigation, a new segment of Distribution Integrity Management Programs.

Estimates place the number of cross bores in the United States at up to 1 million.

The number of destructive incidents is more difficult to pin down, but between 2000 and 2010 there were 18 known cross bore related explosions, averaging approximately two incidents per year. Steps are now being taken to prevent new cross bores.

However, the only way to prevent deaths from existing ones is to manually inspect every length of sewer pipe in the country. Cross Bore Detection and Mitigation was created to accomplish this immense task.

Utility companies own the risk related to cross bore incidents, and thus the responsibility for preventing them. Knowledge sharing occurs industry-wide with the common goal of helping everyone develop the best cross bore program possible.

That said, there is a notable lack of standardization in the tools and methodologies implemented to accomplish find and resolve cross bores.

a map of known cross bore related explosions

In the Common Ground Alliance’s 2018 Technology Report: Technology Advancements & Gaps in Underground Safety, the organization identifies thirteen areas related to mapping and GIS that need technological solutions:

13 Underdeveloped GIS features for Cross Bore Programs

  1. Accurate mapping of underground facilities
  • High-accuracy GPS collection and mapping of assets - less than 1 meter
  • Collection of Z data and depth of cover over assets
  1. Mapping near misses - collecting and enabling use of this data
  1. Mapping damage locations
  1. Enabling data sharing
  1. Identifying facilities currently not mapped, recorded or known
  1. Making the GPS mapping technology usable by construction crews
  1. Integrating GPS mapping and GIS in real time and workflow
  1. Using routine maintenance opportunities to GPS-record assets
  1. Creating “open” GIS systems/better sharing of the data
  1. Mapping assets through mainline inspections and associating location with video
  1. Providing better GPS signal strength in urban canyons and under tree cover*
  1. Providing software analysis for quality feedback about GPS coordinate collection
  1. Developing standards for GPS data quality

*Not addressed in this blog

This blog proposes the implementation of Mobile GIS to address 12 of the 13 issues above - helping to save lives by creating a faster, more cost effective legacy cross bore process.

New to GIS? Check out Unearth’s introductory guide.

Goals and Challenges of Cross Bore Programs

A typical cross bore program has two divisions: legacy and preventative.

Legacy focuses on finding and repairing existing cross bores, while preventative prevents new cross bores from occurring during future construction projects. Both divisions are vital to safety and security. However, the legacy division faces a far more daunting and time consuming task that addresses the most immediate threats to safety.

For the purposes of this blog, we will focus on legacy cross bore programs only.

legacy and preventative cross bore programs side-by-side

A standard legacy cross bore program contains the following parts:

Risk Assessment

Objective: To determine the risk of a cross bore incident and prioritize areas for inspection by analyzing parcel and plat data.

Challenges: Risk assessment involves sorting, organizing, and analyzing massive amounts of data related to a broad physical location. The results must then be organized in a way that is easily accessible and understandable for the next step. The heavy amount of data related work is time-consuming and resource intensive.

Inspection Packet Assignment

Objective: Individual inspection teams must take their assignment, run a sewer scope for each parcel, and precisely record the results.

Challenges: Each field team and each contracting company must develop their own process of recording data according to the materials provided to them by the utility company. These methods often rely on a mixture of PDF files and paper, and require information to be copied by hand multiple times. The lack of standardization and digitization introduces a wide opportunity for error.

a sewer cam operator inspecting for cross bores

Parcel Inspection

Objective: The contractor must take the inspection packet assignment from the utility and effectively distribute the work to their field teams while accurately tracking the progress.

Challenges: Many potential issues arise in this step, as it’s the first instance where instructions are passed through multiple people. The challenge for the utility company is making sure their packet assignment is easily understood, while the challenge for contractors is making sure they properly understand the assignment and can effectively optimize their work and inspection routes. If wires are crossed here, inspections won’t happen properly and work will need to be redone.

Data Capture

Objective: To effectively transfer inspection data from the field to the utility company.

Challenges: Transferring this large quantity of data results in a number of pain points. Video evidence is often sent in DVD format, which makes it highly challenging to review quickly. Map data must also be compiled and sent off in a way that coordinates with the video data. The combination of physical media and digital documents leads to a slow and disorganized data transfer process that can severely delay schedules and result in lost data.

QA/QC Review

Objective: It’s the responsibility of the utility company to verify the data sent to them by their contractors, ensuring it meets accuracy and standards guidelines. The QA/QC review process exists as a failsafe step to make sure that no cross bore goes unnoticed. If the utility company finds a problem, the information must be sent back to the contractor to be reviewed and reinspected.

Challenges: This step can be a significant time drain. With no standardized methods of data collection and no organized reporting, error rates can be quite high. Higher error rates means significant delays as reports must be sent back and forth for multiple inspections.


Objective: Once the data has been verified, it must be transferred into the utilities preferred format of record, distributed to the appropriate teams, and then stored for future reference.

Challenges: Cataloging introduces more room for error, as data must be transcribed once again. It also creates another bottleneck in the cross bore process because it’s an expensive, manual effort limited by the amount of people devoted to the process.

In laying out the steps and challenges of a legacy cross bore program, a clear theme emerges. The utility industry needs a standardized, simple system of record that maintains a single source of truth from the beginning to the end of the process. Only one category of software comes close to addressing these needs: Geographic Information Systems (GIS).

The Role of GIS in Legacy Cross Bore Programs

GIS refers to a broad group of data management systems that organize information by location - two well known examples are Google Earth and ESRI.

GIS technology typically features a set of powerful tools for a variety of advanced data applications. Unfortunately, the complexity inherent to this type of software typically limits its accessibility to only professionally trained personnel.

For legacy cross bore work, the basic function of GIS software is to enable a utility to properly document inspected sewer lines on a map of their territory. In an ideal world, GIS software would be the foundation of a legacy cross bore program - from identifying and assigning work, all the way to cataloging inspected parcels.

an office worker using desktop GIS

Unfortunately, most GIS software is too cumbersome to be used efficiently by each individual involved in the cross bore mitigation and detection process. So, instead of becoming an essential tool to accomplishing work quickly and accurately, GIS becomes an inconvenient requirement of the data storage process.

If utility companies are ever going to effectively find and resolve every cross bore instance across the millions of miles of sewer infrastructure in the United States, they’ll need to streamline the use of GIS technology.

The industry must go beyond the current capabilities of modern Desktop GIS software, and work to create a map-based workflow that allows flawless communication and data transfer between the office and the field.

Going Beyond Desktop GIS: An End-To-End Approach to Legacy Cross Bores

The missing piece of modern GIS is its inability to be used by everyone involved in the cross bore detection and mitigation process.

This roadblock exists for a number of reasons:

  • Data structures in GIS are not optimized for mobile devices or mobile networks
  • GIS requires expensive and powerful local hardware to run
  • Licensing structures are cost-prohibitive and restrictive, particularly when it comes to field teams

These are the weaknesses of Desktop GIS - powerful, yet complex technology installed on a computer, which doesn’t translate well to the field.

To go beyond GIS, the utilities industry needs to implement a map-based system that doesn’t just store geospatial data, but also optimizes the process of cross bore detection and mitigation itself. In other words, utilities need Mobile GIS.

a utility field worker using mobile GIS in integrity management

Effective Mobile GIS provides:

  • Mobile first design with data structures created for delivery over mobile networks
  • Cloud-based architecture that eliminates the need for powerful local hardware
  • A simple user experience that lets anyone pick it up and use it instantly
  • An adaptive license structure that’s flexible enough to meet the needs of scaling with field teams
  • A feature set that is still robust and powerful enough to meet the enormous data requirements of cross bore mitigation and detection

With these pieces in place, a legacy cross bore program could be simplified and streamlined into a few steps that all take place in a single system:

  1. Upload or select the area that needs to be inspected.
  1. Assign the area to a designated field team.
  1. The field team marks their inspection directly into the system from the field.
  1. Maps and all associated data are instantly available for review by the utility.
  1. Once reviewed, the process is finished. There’s no need to transfer to another system of record.

If the utility industry can find a system that allows them to overhaul the legacy cross bore process in this way, the speed and accuracy of cross bore detection and resolution will drastically increase.

Even better, if the industry can agree upon a standardized system and process, it can work together to help cross bore detection and mitigation evolve to be even faster and more streamlined.

Why Invest the Time and Effort to Procure Mobile GIS?

Ultimately, legacy cross bore programs are about saving lives.

With estimates of cross bores occurring at a rate of .4 for every mile of pipeline, and with 2.5 million miles of pipeline in the United States, this problem needs to be tackled as swiftly as possible.

In a good year, using current standards, a utility company can potentially clear around 35,000 addresses. Extrapolated out, that means clearing a large territory of 5 million addresses would take almost 150 years!

The hard truth is that with the current process, it will be impossible to ever fully complete a cross bore program in an acceptable time frame. With cross bore incidents occurring at a rate of about 2 per year, that’s a significant number of lives at risk.

If legacy cross bores are ever to become a thing of the past, and the risk of injury and death eliminated, the industry has to figure out two things:

  1. How to make the process faster
  1. How to make the process cheaper

A new method of GIS is the mission critical task to accomplish these objectives; it offers the most opportunity to advance the goals from both a short and long term perspective.

Short Term Benefits

End-to-end inspection speed can be significantly increased by simplifying time-consuming tasks and eliminating redundant steps in the assignment, inspection, and review processes. 

As speed increases, the cost to inspect a parcel comes down, allowing teams to inspect a broader area for the same amount of budget. Additionally, as the number of systems involved declines, the budget spent to maintain them can be redirected toward other expenses, such as assigning more inspection packets.

a utility field worker inspecting for cross bores

Long Term Benefits

The long term is where moving beyond Desktop GIS gets really exciting. Once inspection data begins to accumulate in a single system, the possibilities of what you can do with that data increase exponentially.

The most exciting prospects involve the potential for predictive analysis. With enough inspection data, utilities can begin to automatically identify areas with a high risk of cross bores, prioritize them based on their internal criteria, and then create a predictive schedule for when their entire service area will be free of legacy cross bores.

Modernizing the GIS standards of legacy cross bore programs is the essential first step in eliminating latent cross bores nationwide. Without a solid foundation, progress will continue to be slow and costly, making it virtually impossible to get rid of this threat.

A Step-by-Step Approach to Mobile GIS Adoption

It’s one thing to discuss reforming GIS processes for legacy cross bore inspections from an abstract perspective; it’s another thing to actually put the reforms in place.

Many utility companies, as well as outside vendors, have tried to put together an easy-to-use mapping system from existing GIS tools - none of them have accomplished their goal. Why? Because existing GIS tools were built decades ago and have an outdated architecture that holds them back.

So how can a utility company actually go about reforming their GIS tools to improve legacy cross bore detection? It’s not as difficult as it seems. However, it does require looking to outside sources to accomplish it.

Here’s a step-by-step guide to how you can get it done:

1. Identify the program manager for legacy cross bore inspections

Before anything can get moving, you have to get the right people together. Find the person responsible for legacy cross bores, and then create a spreadsheet of everyone within the utility company that has a role in running the program.

If no one is in charge of legacy cross bores, go to the person running preventative cross bores and find out why you don’t have a legacy program. If there is no cross bore team, you need to have a broader org-wide conversation. Go to the person in charge of risk management and find out why cross bore mitigation is not a priority.

2. Lay out your current cross bore inspection process step-by-step

Now that you know everyone involved, you can map out your exact process to find and mitigate cross bores. Start with how you prioritize parcels and plats and go through to recording and storing the results.

You should identify the individuals involved, the average time spent per step, the systems used, and the associated costs. This will give you a good high-level overview of what’s going on internally.

3. Calculate the total time and cost of finding and resolving cross bores, then create some projections

This is an essential step because you need to have a baseline reading of where your cross bore program is today, and how it’s projected to perform.

With the numbers from step 2, you should be able to determine an average time and cost to inspect a single parcel. With these numbers, you can calculate the time and cost of inspecting every customer served by your utility. This overall number is critical because it will show the value of investing in a different system in terms of time and money saved.

4. Research and evaluate outside software providers

Many utility companies make the mistake of trying to build an internal solution for their Mobile GIS.

The money and time spent developing a working tool will quickly outweigh the benefits received. The complexities of GIS require a dedicated software organization to build, manage, and scale operations. Finding a purpose-built Mobile GIS tool for legacy cross bore programs can get you up and running in a couple weeks for a fraction of the cost.

For this step, you should build a spreadsheet of available options that lays out their cost, licensing structure, features set, plus pros and cons. Only include tools that will support an end-to-end workflow, as that’s the key function that will streamline the entire process.

5. Talk to your top three software options

You shouldn’t try to purchase and implement this kind of solution out-of-the-box. Each provider you’re considering should offer a certain level of customization, onboarding, and specialized service. This is also your chance to discuss the numbers and processes laid out in earlier steps, as well as create a firm outline of the tangible impact these vendors could make.

6. Make a decision and get buy-in

Once you’ve decided on a provider, you have to get organizational buy-in. This is potentially the most difficult/time-consuming step.

Fortunately, the Mobile GIS you choose should be of significant help here - particularly if you followed the earlier steps involved in laying out and analyzing your current process. The provider you choose should be happy to provide you with all the materials you need to help present the solution to the broader organization. Many will even fly people to your company to present if you want additional help.

7. Roll it out

With everything in place, you’re ready to put your new system to use. Work with your software provider to develop a rollout plan.

They should have a system for getting you and your teams onto the platform smoothly. Everyone should have a detailed set of expectations regarding when and how they will use the software, and a person to contact if they have questions.

8. Track and record results

The final piece of the puzzle is to monitor and record usage.

For the first 3-6 months you should set up regular check-ins with your software provider to ensure that everything is going according to plan. Then after you have a year of data, you can sit down to review performance increases and explore how you can streamline processes even further. From here, the software becomes a natural extension of your operations that can be iterated and developed as needs evolve.

These steps serve as a general benchmark for individual utilities to move towards more efficient legacy cross bore inspection programs through Mobile GIS.

It’s important to keep in mind that the software selection and purchasing process can be long and slow, particularly at a large organization. To stay driven, teams need to remember the ultimate objective: reducing risk and saving lives.

This is a mission critical effort that benefits everyone.

Getting Started with Mobile GIS in Integrity Management

To effectively accomplish the goal of going beyond GIS for legacy cross bore inspections, a new GIS standard needs to be built from scratch - one designed around the capabilities of modern cloud computing and the demands of modern mobile devices.

It’s a task that requires a dedicated software team with experience engineering large-scale solutions for niche industries.

For the last few years, Unearth has been building a Mobile GIS platform designed specifically for the built world. When we discovered the need for a unique, scalable solution to solve the legacy cross bore problem, we instantly knew we were uniquely positioned to provide a solution.

We’ve been working closely with some of the largest utility companies in the nation, as well as their contractors, to build a cross bore focused toolkit for our platform; one that eliminates the obstacles commonly faced by older programs: poor mobile optimization, rigid licensing structures, steep learning curves, heavy hardware requirements, complex user interfaces, and device incompatibility.

We strongly believe in the importance of finding a way to quickly and effectively deal with the legacy cross bore problem in the US, and are excited to be helping the utility industry move swiftly toward a solution.

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