Between the Poles

Combining traditional data with advanced GPR provides a complete picture of the subsurface

When we look at some of the major projects that have gone sideways, it often can be attributed to the lack of planning for underground infrastructure. This is a global issue and we know that the best way to manage the risk from underground infrastructure is to map it before construction begins. For example, the Sydney light rail project in Australia was problematic with a serious budget overrun because there was so many underground unknowns discovered during construction. Another example is a hospital project where what was thought to be a complete inventory of underground utilities missed a 20 inch gas pipe and a six inch gas pipe that were encountered on the project site during construction.  Neither was documented and they were not on the asset owner's records. The challenge is to find these assets before construction in the early stages of planning and design so as to be able to mitigate any project impacts and safety concerns. Very few major projects move forward without an environmental investigation and a geotechnical investigation, so it's not clear why there's resistance to doing a subsurface utility investigation when the immediate risk to the project and the public is considerably higher.

Legacy data

Legacy data is often proprietary asset owners' "as-planned" engineering records. Relying solely on these legacy utility asset records for location information is unreliable, but augmented by GPR and other remote sensing data they provide valuable information.

Modern GIS also cannot be relied on to always provide reliable data. This image is from a GIS with an xref in the background. The middle of the street is where the asset owner believes the water line to be, but a subsurface survey actually found lines on the top and the bottom side of the street, which is nowhere near the placement according to the asset owner's records.

Even more disconcerting is that some asset owners have stopped updating their records. In one example we encountered, the last update and revision to a telecom owner's documents was in 1998. Obviously by 2022, we know there's a lot more utilities added into these streets.

The challenge for practitioners is how to find this information.  Fortunately, advanced technologies, such as multi-channel, multi frequency ground penetrating radar, can augment the available legacy and EM data to provide a complete, accurate and current picture of the subsurface.

Underground locating combining traditional and advanced techniques

At DGT Associates our typical workflow starts with collecting and compiling legacy maps.  We collect all legacy data that is relevant including client information and all the asset owners' maps. We add our institutional knowledge from decades of experience with construction in the particular region where we're working. We then perform our traditional EM pipe locating and add that data to the legacy data we have compiled. Together this provides the background for our ground penetrating radar scanning.

Advanced ground penetrating radar

This is a picture of DGT Associates' new ground penetrating radar setup, a drivable rig with a mobile mapping unit. This is a 24 channel system, so it captures 24 slices every time we scan. It is also a multi frequency system. Low frequencies penetrate deeper with less resolution, while higher frequencies have better resolution but don't penetrate as deeply. This system can collect about 10 miles of data per day with 24 channels for a total of 240 miles of GPR data.  With Boston's soil conditions this system is collecting vertical slices down to about 8 feet. In addition with multiple frequencies we are simultaneously collecting horizontal slices. 

Value of GPR in subsurface surveys

GPR is not magic and is not replacing any of the previous techniques. What is the value of including advanced GPR in locating and mapping subsurface utilities ? The first thing is safety. With our rig we do not require boots on the pavement.  Secondly we get fast data collection compared to traditional locating. Thirdly, we can determine depths with GPR really well. When we see the top of the pipe, we're able to trace it in the cross section. GPR is also good at confirming the location of facilities shown on legacy maps or detected by EM. But GPR can't see everything, For example, we often can see a trench where there is likely a utility even if we can't see the actual pipe or cable. We typically need to determine from other techniques, legacy drawings or EM scanning, what type of utility we are seeing. 

A major strength of GPR is finding unknowns. Going through the depth slices, we can see each one of the lines representing a utility. The type of utility is derived from legacy and EM maps and is colour coded according to the standard with blue being water, orange telecom, purple unknown, and so on. Something that's really striking in this GPR scan is the purple utility buried only a foot and a half deep, crossing diagonally across the street. Nobody knew about this utility before we went out and scanned it with the GPR.

GPR data showing rectangular pits

One of the best examples of how combining GPR with legacy data enables us to detect unknown utilities, determine what they are and confirm they are still present is in Cambridge. We had compiled comprehensive legacy background information before we went out to do a complete GPR scan of the site.  Among the things we found were these unique rectangular pits, shown as purple circles (colour coded for unknown). Each pit is about one foot by two feet wide, and they're regularly spaced at 12 feet. If all we had was the GPR data, we would have no idea what these were.

Background legacy data revealing abandoned gas pipe

But because we had the legacy background maps, we were able to see that these pits line up  with old legacy data showing an abandoned gas pipe. Without the background map, we would have had no idea what the GPR scan was showing. The GPR scan confirmed the location of the abandoned gas pipe and showed that it was still there.

A typical subsurface survey deliverable is colour coded according to American Public Works colour coding. All of the lines are annotated to conform to the ASCE 38-02 quality standard. Every line is represented not only by its annotations for reliability, but also includes the number of conduits and other measures of capacity, and asset owner information. Together it provides as complete a picture of the underground assets for the project site as can be assembled from existing data.

Conclusion

The light rail in Sydney went from a $2 billion to a $3 billion job because of the lack of a comprehensive subsurface survey during planning and early design. There's plenty of proof including ROI studies that there are very good reasons to use SUE surveys. There are good practitioners all over the world who can carry out subsurface surveys. Just as with above ground surveys knowing accurately the location of underground utilities and other infrastructure enables good designs because you can make informed decisions based on information collected by professionals who know what is underground and where it is.

What we see in the coming years is that subsurface surveying is going to become even a bigger business and it's going to become more lucrative. We expect to see more practitioners and more investment in innovative technologies for detecting and mapping underground utilities.

This post is based on Mitchell Lidell's & Michael Twohig's (DGT Associates) talk at the Subsurface Utility Mapping Strategy Forum (SUMSF).

Accurately locating and mapping utility infrastructure underwater

In New Jersey there was a $320 million project to replace a bridge connecting Stafford Township to Long Beach Island. There are many utilities involved including telecom, Comcast, water and sewer, and electric and conduits. They have carried out a SUE survey prior to construction to try to determine where the utilities are and have also come up with mitigation plans to reduce risk. 

However there was a complication. They need to build a new drain line because there has been increased flooding during the rainy season and also because of high tides. It is planned to build the drain line into the water parallel and fairly close to an existing water main. But the water main that provides water to the island runs under water and all they had for locating the water line was an "as-planned" map from the water company engineering department, which is not reliable data. Cross-boring into the water main would leave the whole island without water. Traditional locating equipment, such EMI and GPR, cannot be used under water so an alternative locating technology was required. 

PRISUM Technologies provides a technology called inertial navigation technology, gyro mapping or inertial measuring unit (IMU) that relies on a battery powered autonomous probe with on-board gyroscopes, accelerometers, and odometers. The mapping tool records changes in direction and speed at a hundred samples per second (every foot) to create an accurate, high frequency 3D profile of the pipe segment being traversed. Inertial mapping avoids the major limitations of surface-based EM and GPR techniques; it is not sensitive to soil conditions and extraneous electromagnetic noise, is water resistant, works with all types of pipe materials and is safe because it does not require boots on the pavement. It can map sewer and water mains, electric power or telecom conduits, gas and oil of any material, plastic or metal.  Pipe diameter can range from an inch and a quarter to 30 inches. The key to the technology is that the IMU is completely autonomous. There is no tethered cable and it does not communicate a signal to above ground equipment. All the data is stored within itself.  Basically it is comprised of a battery, memory and various inertial devices such as accelerometers and odometers in a compact device that can be pulled or pushed through a pipe or conduit. Once the IMU tool has been run through the pipe or duct, it is removed from the pipe and connected to a laptop to download and process the data.  The output is a report and a CSV file or a standard GIS format such as a shape file. Because of its autonomous nature, it can map utilities which are going under rivers or other obstructions, even a hundred feet or deeper. The IMU tool has the capability to map up to 5,000 feet recording X,Y and depth every one foot.  To georeference the collected data, accurate GPS coordinates are recorded at the insertion point and and at the end point.  With that information the entire path the autonomous unit travelled can be determined. 

In New Jersey the IMU was inserted in one end of the water pipe and pushed through to the other end and then pulled back.  This was repeated providing four runs. The data from the four runs showed a high degree of repeatability providing confidence in the accuracy of the data. According to the New Jersey DOT, the locating standard tolerance is plus or minus 2.74 feet horizontal and 1.09 feet in depth. The 3D mapping data collected by the IMU was much more accurate, 0.26 ft in XY, and 0.3 ft in Z.

This project entailed a one day activity where we were able to both run the IMU tool through the water main collecting data and also process and show the results to the New Jersey DOT on the same day. The overall operation time for the IMU run was two hours.

It was found that the water main actually had been installed at an angle.  If the team had not had the accurate location from the gyro mapping run, shown by the the red line, they would have risked cross-boring into the water main with major consequences for the project and the island's water supply. With the accurate location of the water main in hand, the team went back to the drawing board and redesigned the new drain line ensuring a safe separation from the water main.

This post is based on Santosh Saride's talk at the Subsurface Utility Mapping Strategy Forum (SUMSF).

Developing a subsurface digital twin for Singapore requires data quality management

Singapore has severely limited land, but unlimited space and has started to build many types of activities underground to save the land above ground for the better living of citizens. Many of the traditional utilities such as electric power, water, wastewater and others, as well new type of utilities, such as the Pneumatic Waste Conveyance System are almost one hundred percent underground. Parts of the transportation network, such as the metro, are also underground.  In addition some storage, waste disposal and national defence facilities are underground.

Data quality

As underground development expands in Singapore reliable data about the location of underground infrastructure becomes increasingly essential. Data quality is a huge issue. Virtually all stakeholders are aware that much of the available information is unreliable and that this has repeatedly led to losses of time, money and opportunities.  From the perspective of planning and land administration, infrastructure development, and planning and design there are important benefits in the form of reduced uncertainty and risks to be derived from reliable underground data.  These include reduced costs, avoiding unnecessary rework, minimizing destruction to the environment, avoiding disruption of consumer services, and greater safety for people working in the environment as well as the general public in general.

To address this issue the Digital Underground (DU) initiative was started in 2017. The objective of DU is to develop a reliable map of Singapore's subsurface infrastructure for planning and land administration. The DU has four phases. The objective of Phase 1 was to identify the problem and create a road map. The second phase involved looking into what was required to create a utility mapping ecosystem. The current phase involves looking at the underground utility workflow which has many components that will contribute towards reliable data.  The final phase is the operational phase when we implement a new utility mapping ecosystem.

In Phase 1 an assessment was made of the reliability (locational accuracy, completeness, and currency) of the existing data. It was concluded that the data quality of the data is seriously deficient. In terms of location, it is  inaccurate, much of it is out of date, and it is also incomplete. It was also found that the quality level of the data is undefined, in other words, no quality level has been assigned to each facility for example based on a quality standard like ASCE 38 or PAS 128. We do not know which piece of data is of higher quality or which piece of data is sufficiently reliable to be relied on for planning and land administration.

Road map for improving data quality

Addressing data quality involves fundamental survey, locating and mapping issues. In addition to assessing data quality an objective of Phase 1 was to develop a road map for addressing the data quality issue. First we wanted to ensure that going forward data for all newly installed utilities would be reliable. In 2017 we implemented a strategy requiring certified survey quality as-builts. Secondly, we started to look for opportunities to improve the data quality of existing below ground infrastructure. We are looking at several new technologies, such as ground penetrating radar and gyro mapping for detecting underground utilities and LiDAR and photogrammetric capture with a smart phone of trial trenches. We are also exploring ways of capturing not just vector data, but integrating 3D point cloud data of an open trial trench in our GIS so the next person interested in this section of road doesn't have to open up the trench to see what's there.

A key part of the road map is governance, especially accountability and transparency; assigning responsibilities for data capture, data quality improvement, and data quality management. We want to introduce a new framework so that we can ensure high quality utility data ongoing in the future. We are suggesting a process that would not interrupt or change the current utility workflow, but add a new data quality workflow on top of the current workflow. Asset owners will be able to continue to do their work the way they have in the past, but will be required to submit their data to a Data Quality Hub for quality control to ensure that data quality standards are complied with. We intend to implement quality control on the front end when data is submitted to the database, not at the tail end of the information supply chain. Eventually this process is intended to ensure that we are getting reliable and high quality data that can be shared back again to the end user, the planners and land administrators.

Community of practice

Creating a utility mapping ecosystem requires buy in from network owners, transportation agencies, excavators, and others. The Digital Underground Connect is a platform where we provide people to meet, to learn and to improve.

 

This post is based on Victor Khoo's talk on the Singapore Digital Underground Project at the Subsurface Utility Mapping Strategy Forum (SUMSF).

Key initiatives of importance to the global geospatial+AEC subsurface digital twin community

Two initiatives of importance to the global geospatial community will begin this June.

Expanding Responsibility for the BetweenThePoles blog

First of all we are expanding the BetweenThePoles blog from a single content provider (Geoff Zeiss) to an industry collective that will be able to mine many more geospatial industry players. Geoff is stepping down from day to day responsibility for the blog (he doesn't like the word retiring) and ownership and administration will transition to GoGeomatics Canada, advised by a collective of industry leaders in the geospatial+AEC sector.

The content and aims of BetweenThePoles will remain the same. The blog encompasses the application of geospatial technology in architecture, engineering, and construction (AEC) and utilities. Primary focus areas are worldwide legislation, governance, regulations, and new technologies for mapping underground utilities and enabling subsurface digital twins, CAD+GIS and BIM+geospatial integration to enable full lifecycle construction, and innovative technologies for vegetation management for electric power utilities.

By way of background the BetweenThePoles blog was initiated in 2006 by Geoff Zeiss. Since then the blog has hosted over 2,500 posts and received over 1.3 million lifetime page views. Currently 3,500 active users access the blog each month. The blog will be continued with its current focus; mapping underground infrastructure,  BIM+geospatial integration, and innovations in vegetation management for utility transmission and distribution.

Making Subsurface Utility Mapping Strategy Forum (SUMSF) and Annual Event

The second initiative follows on the very successful Subsurface Utility Mapping Strategy Forum (SUMSF 2022), which was a follow-up event to the Canadian Underground Forum in 2021.

The genesis of SUMSF is found within Canada’s National Geospatial Conference, GeoIgnite. In 2021 Jonathan Murphy and Geoff Zeiss came together over the idea to create a leadership and technology forum on the theme of underground infrastructure mapping. With the help and financial support of the global underground mapping industry the Canadian Underground Forum (CUF 2020) was held virtually in 2021. From this success, a new and larger stand-alone event with a new global brand and perspective was launched in 2022, the Subsurface Utility Mapping Strategy Forum (SUMSF 2022). 

SUMSF 2022 was held virtually March 22nd and 23rd 2022 again with the support of the underground mapping industry. SUMSF was themed to bring together individuals and organizations to share information about and contribute to improving the mapping of underground infrastructure. This online conference brought together exceptional speakers in the underground locating and mapping sector and was well attended by the geospatial and engineering community.

Based on the success of these two events GoGeomatics Canada has decided to make the conference an annual event. Next year, SUMSF will be held virtually March 6th and 7th. SUMSF is hosted and presented by GoGeomatics. Like BetweenThePoles blog, it will be advised and supported by industry leaders with the support of the SUMSF LinkedIn Group. 

BetweenThePoles will remain an important platform for communication and engagement on the the application of geospatial technology.  

Anyone interested in joining the collective for the BetweenThePoles blog are encouraged to contact Jonathan Murphy at GoGeomatics Canada. As well anyone interested in joining the advisory committee for SUMSF 2023 is encouraged to do the same.

Geoff Zeiss

Standards-based subsurface data model key objective of New York's underground infrastructure resilience project

Improving disaster resilience requires accurate data about subsurface utility and other infrastructure. New York has has experienced several disasters over recent decades, foremost among them 9/11 and Hurricane Sandy. The experience of 9/11 and Hurricane Sandy showed that communities interested in addressing utility resilience currently have little access to underground infrastructure information, which is typically siloed in network owners/operators' proprietary systems, is rarely integrated with other data sets, and is inaccessible to the excavators, disaster planners, emergency responders and others who need it. The UNUM project, funded by the National Science Foundation, is designed to address the challenge of creating a single accessible map of all of New York's underground infrastructure to support emergencies and disasters such as 9/11 and Hurricane Sandy.

Underground infrastructure mapping in NYC

Over the past decades the City of New York has initiated several projects involving underground utility networks. The first project was the conversion of citywide paper maps of water mains into CAD format. The water supply map was near completion when the city began the development of the citywide base map in a GIS. The base map provided locationally accurate platform, including block, lot, street, buildings and photogrammetric imagery of the entire city. Since then most agencies have contributed their data to the base map project which is virtually all open and publicly available. The city's sewer paper maps were entered into the GIS and the water main maps were converted from CAD to GIS.  Both sewer and water main maps were integrated with the city base map, demonstrating the ability to use city's cadastral map data for underground mapping as well.

9/11 emergency

Within hours of the World Trade Center attack, an interim site was equipped to response to the emergency. The Emergency Mapping and Data Center was set up to respond to map requests. The map grid of the site was developed by the Fire Department of New York to enable first responders to navigate the site safely. In addition, maps were developed to advise citizens of street closing and outages of utilities. Maps were submitted to the media and newspapers with daily updates of these conditions for citizens. Thousands of maps were created and distributed within a six week period.The operation was nonstop for more than 18 hours a day for three months. The Deep Infrastructure Group (DIG) team digitized data of the World Trade Center site provided by infrastructure agencies and utilities. The digitized maps enabled first responders to navigate the site safely.  The combination of photogrammetry and LiDAR, revealed the location of fires burning underground. Freon becomes a poisonous gas when heated and locating the underground tanks enabled safe removal of the freon and the tanks themselves, preventing loss of life of workers on the site and residents in surrounding areas. This is a classic example of the value of knowing the location of  underground infrastructure.

The 9/11 emergency clearly demonstrated the value of compiling an integrated data set with a common base map that can be shared easily and quickly among all players. But the 9/11 experience also revealed the difficulty in achieving an integrated map with the currently available data sets and integration tools and was a primary motivation setting the directions for the UNUM project.

Unification for Underground Resilience Measures (UNUM)

To directly address the challenges experienced during these events the Unification for Underground Resilience Measures (UNUM) project was initiated to investigate subsurface data development, integration and interoperability options. Overcoming these barriers to data integration requires the design of an integrated 3D data system with robust security and data protection that is capable of integrating data from different network owners, municipal and other sources based on a standardized subsurface data model and a willingness to share data securely among all stakeholders.  One of the key goals of the the project is the development of a detailed road map for the implementation of a standards-based subsurface data model capable of integrating all of NYC's subsurface data from multiple sources into a single map.

UNUM involves two pilots in NYC neighbourhoods: Sunset Park, Brooklyn and the Grand Central Business Improvement District. These community test beds will be used to refine an infrastructure data integration strategy and to assess the vulnerabilities of utility infrastructure. The New York City pilot area are far apart in terms of demographics, diversity of their populations and their economic bases. They also differ widely in the types of underground infrastructure problems they have experienced.

Use cases addressed by UNUM

The UNUM project, which is supported by a National Science Foundation (NSF) grant, addresses emergencies and disasters that are related to underground infrastructure. Emergencies are typically characterized as localized incidents with limited damages while disasters are more wide ranging, cover a lot of area, cause a large amount of very expensive destruction. NYC has experienced two disasters in the last two decades: 9/11 and Hurricane Sandy.

There are many use cases that involve underground infrastructure. The UNUM project is focused on just two uses cases; emergency response and disaster planning and response. Other projects in NYC target other cases including excavations, excavations for new foundations, maintenance, smart cities, digital twin, and so forth.  For UNUM's use cases the data focus is on the subsurface utility networks, their features and attributes and their relationships to one another.

Quality and availability of subsurface infrastructure data in NYC

Over the past years extensive research has been carried out to determine what data is available in NYC and who is responsible for each data set.  It has been found that there is actually a fair amount of data. New York City itself, which manages the water and sewer utility systems, has very good data which is open and publicly available. In contrast for private utilities such as Con Edison, National grid and Verizon, knowledge about the structure, depth, and reliability (completeness, currency, and accuracy) of their data is uncertain because other than the through the 811 Street Markup (one call) system, there's very little sharing of this data. In general most of the underground utility and communications network data in NYC is within silos that are rarely, if ever, integrated into a single data set and are inaccessible outside of the networks owners themselves.

Single integrated map

The  The vision which motivated UNUM is a single integrated data set that can show all the different utility layers reliably (accurate, up to date, and complete) in 3D, together with other related GIS layers, registered to a common base map and georeferenced to a common, horizontal and vertical datum. This would reveal conflicts, interdependencies, and risks for cascading effects for NYC's utility network. Subsurface utility engineering (SUE) surveys are becoming more commonplace and data like this is becoming available for individual construction projects. This data is being captured in a GIS and compiled entire networks making it possible to see how different networks (electric, gas, water, sewer, steam, fibre,copper, etc) relate to one another.  Especially important are interdependencies such as telecom systems that require power, pumped water and wastewater systems, and virtually all utility systems that rely on digital communications because of the potential for catastrophic failure involving multiple networks.

An open standards-based model for underground infrastructure

To achieve the vision of a single map of New York's underground infrastructure will require developing a data model that encompasses all of NYC's underground infrastructure and that could form the basis for a subsurface digital twin for the city.  Bringing the relevant data together during 9/11 took weeks to do because the different data sets were not only in a variety of formats but each had a different data model. UNUM decided to take a standards-based approach and has adopted the Open Geospatial Consortium's Model for Underground Data Definition and Integration (MUDDI).  This model has the additional benefit that it is  is supported by the American Society of Civil Engineers (ASCE) 38-22 and 75-22 underground utility standards.  For NYC adopting the MUDDI model makes it possible to build on the work already done by other jurisdictions including Scotland, the Ordnance Survey of Great Britain, Denmark, Flanders, Netherlands, Singapore and others. Experience to date with the model has shown that the MUDDI model is comprehensive and able to describe all the key features that are found underground in NYC.

The illustration shows a conceptual picture of all the things that can be captured and integrated through the MUDDI model. At the centre are individual network features such as cables, pipes, valves, transformers, switches, and meters. Shown below the features it can be seen that each feature has attributes (age, material, location, dimensions, quality level, threat level, pressure, voltage, fiber capacity, etc) and lower right accessory features (access, support structure, container, serial#, etc). Underground facilities are surrounded by a natural environment (soil, geology, ground water, chemical contaminants). Together the network features, their attributes, supporting structures, and environment comprise the utility networks themselves.  Utility networks can be be represented in a GIS and related to other layers such as catchment areas, service districts, preservation districts, and so on.

New York intends to develop a detailed model (referred to as a profile) for the city's underground infrastructure based on the MUDDI conceptual model. The same conceptual model is being used in other jurisdictions. For example, in the UK the National Underground Asset Register (NUAR) project has created a UK profile for the excavation use case. Over the next few years based on this profile, all utility and communications networks in England, Wales, and Northern Ireland will be captured and integrated into a single map.

Conclusion

Improving emergency and disaster resilience requires accurate data about subsurface utility and other infrastructure. The 9/11 emergency clearly demonstrated the value of an integrated data set with a common base map that can be shared easily and quickly among all players. But the 9/11 experience also revealed the difficulty in achieving an integrated map with the currently available data sets and integration tools.The vision which motivated the UNUM project is a single, integrated and accessible map for New York City that integrates reliable location data for all of New York's underground utility layers in 3D, registered to a common base map and georeferenced to a common datum. To achieve this will require a shared data model enabling location and other data from different utilities and other sources to be integrated into a single map of New York's underground infrastructure  UNUM has taken a standards-based approach and has adopted the Open Geospatial Consortium's MUDDI model, also used by other jurisdictions such as the UK. The UNUM project is developing a road map for the creation of a shared data model encompassing all of the city's underground infrastructure based on the MUDDI model. 

This post is based on Rae Zimmerman's, Alan Leidner's and Wendy Dorf's talk on the UNUM project at the Subsurface Utility Mapping Strategy Forum (SUMSF).

Achieving high quality underground infrastructure location data requires accountability

In many jurisdictions worldwide the low quality of underground infrastructure location data has been identified as a top cause of underground utility damage. Existing underground data, most of which is stored in network owners' utility records, is inaccurate, out of date or simply missing.  In North America in a survey of 402 locate professionals better facility maps received nearly unanimous agreement as a top strategy for improving the efficiency and quality of locates.  Singapore's Digital Underground project is unequivocal about the impact of low quality underground location data stating that "virtually all stakeholders are aware that much of the available information is unreliable and that this has repeatedly led to losses of time, money and opportunities." 

Achieving high quality underground infrastructure location data

Singapore

Recognizing the economic and societal impact of inaccurate, outdated and incomplete maps of underground infrastructure, Singapore Land Authority's Digital Underground Project has created a new data governance initiative designed to improve data quality and provide the basis for a national authoritative single source of truth.  Chief among its provisions is the creation of a national Data Quality Hub comprised of a consolidated underground infrastructure database maintained by data flows which enforce data quality management.  Specifically the Data Quality Hub requires all newly captured data on subsurface utilities to undergo quality control based on a defined set of rules before the data is eligible to be included in the database.

North America

According to a recent report from the Next Practices Initiative of the Common Ground Alliance the damage prevention industry has reached an inflection point. For more than half a decade, the rate of damage to underground infrastructure in North America has increased or remained stagnant. The North American one call system has become highly inefficient and industry confidence in the system has been eroded, resulting in a process that has stalled and is not achieving its primary goal of reducing damage to underground infrastructure.

Utility company records comprise the vast majority of the data we have about underground utilities. Much of this data is inaccurate, out of date or simply missing (especially in the case of abandoned infrastructure and infrastructure without a known owner). It is estimated that over $10 billion is spent annually in locating underground utilities and other infrastructure. Most of this is routine locate operations conducted by locators in response to a one call request, but it includes locate operations such as hydro vac services contracted by excavators. Most of this newly acquired data is not recorded or shared. 

To begin to address this crisis by taking positive steps to reduce the frequency and severity of underground strikes in June, 2021 the Infrastructure Health & Safety Association (IHSA) initiated a utility strike Root Cause Analysis and evaluation workshop.  The workshop focused on identifying the primary causal factors of underground strikes. Based on this analysis the group identified five key industry systemic weaknesses that were responsible for underground utility strikes. The workshop made several recommendations to address these systemic weaknesses.

Data quality responsibility

Among the key industry systemic weaknesses identified by the IHSA was lack of accountability.  An essential part of any conversation about data is who is responsible for each data element. When a data source reports that the accuracy of the location of a cable or pipe is within a half a meter horizontally and a meter vertically, I need to know who captured the data, when, with what type of  equipment was used (metadata) and most importantly who took responsibility for the data by signing off for it. If it came from a SUE survey signed by a professional engineer, I will have greater confidence in it than if the data was sourced from utility records with no professional taking responsibility. Furthermore, metadata and a sign-off by a professional enables an informed conversation about whether the newly acquired data is better and should replace the existing record.

One of the things that needs to be clarified in the context of underground infrastructure location data is the roles of locators, professional surveyors and engineers, network operators, and one call centres in collecting and certifying data. For example, Colorado and Montana require as-builts from recently completed public construction projects to be signed off by a professional. In most jurisdictions SUE surveys also must be signed off by a professional. Understanding the equipment used to gather information and the reliability of that technique in that particular project situation is the responsibility of the person putting their sign and seal on the data. To choose and assign the appropriate coordinate system requires a professional surveyor who will also tie that decision in with with the existing project-level coordinates or survey coordinates and make sure it all fits together for the overall project. Assigning quality levels compliant with the ASCE 38 and CSA S-250 here in Canada requires sign off by a professional engineer. In North America professional land surveyors and professional engineers carry insurance that is designed specifically for them in the case of liabilities.

Achieving a high data quality level for existing infrastructure requires upgrading the quality of the huge volume of existing data. Accurate as-builts and SUE surveys will play an important role, but given the huge volume of data, it seems clear that utility owners, locators, municipalities and one call centres will have an essential role to play in upgrading the quality of the data we hold about existing infrastructure. To enable this to happen two recommendations of the IHSA Root Cause initiative are relevant. 

• Identify roles and responsibilities to promote accountability among employers, supervisors, and workers as well as Ontario One Call, utility owners and municipalities.
• Review and enhance practices, procedures and regulations to foster accountability including policies, procedures, and regulations relating to the completion and review of locates prior to excavating and the overall planning and execution of work in the vicinity of underground utilities.

The CGA Next Practices Initiative makes a strong case that a centralized national map of underground infrastructure accessible all construction stakeholders provides systemic benefits with a large ROI for the construction industry. It represents a large opportunity to accurately locate and record location data for the millions of miles of existing underground infrastructure. To do this efficiently will require new and innovative technology for locating existing underground infrastructure, capturing and sharing underground infrastructure information. More importantly it will require policies, procedures, and regulations to promote accountability among everyone involved in locating underground infrastructure and capturing location data including network owners, locators, municipalities, and one call centres.

Real time underground utility detection and damage prevention during excavation

According to the Common Ground Alliance, excavation practices have been the root cause of between 30 - 50 % of annual damage incidents between 2015 and 2020. Now an innovative technology Live Dig Radar (LDR) has been developed by RodRadar which is designed to avoid damage by detecting subsurface utilities in real time during excavation is entering alpha testing of production systems with contractors and others.

Integrating GPR into excavation equipment

The Live Dig Radar (LDR) system integrates ruggedized Ground Penetrating Radar (GPR) antenna and electronics into a digging bucket that can be attached to excavating equipment such as backhoes. The GPR is connected to a rugged tablet installed in the operator's cabin. Immediate visual and audible alerts are provided in real time to the operator, providing him or her with usable information, including the position and depth of subsurface utilities detected during excavation. LDR can detect any type of utility including metallic and nonmetallic pipes, cables, communication lines in plastic conduits, and ducts. LDR's GPR is able to detect very shallow utilities, which is a known barrier for some state of the art GPRs.

How does it work ?

The process is simple; the backhoe operator sweeps the LDR bucket over the area where he intends to dig next. He gets immediate audio and visual feedback showing the location and depth of any utilities detected. If none are reported, he knows he can safely perform the next dig. Then the process is repeated until the hole or trench is completed or a subsurface utility is detected.

As an example, here the LDR operator screen shows that multiple utilities have been detected, two in this case, about 12 and 20 inches deep. 

Another example shows detection of fiber optics in conduits. The LDR detected in real time shallow communication lines in plastic conduits. These lines ran across a job site in a different position from what had been marked. LDR enabled the operator to detect and map these lines and change his excavation plan.

It is well known that radar penetration is affected by soil conditions such as moist soils and clay. But with LDR since it focuses on just the next digging area, the RF signal never needs to penetrate more than a meter into the ground so that soil conditions do not represent a practical limitation on the system. Experience with the LDR unit in very harsh conditions including wet soils and clay has shown that it is able to detect, for example, fibre optic cables buried shallowly in clay.

The hardware and software of LDR have been in development over the last few years. Rod Radar has worked In cooperation with some of the biggest excavation machinery companies to ensure that the ruggedized antenna and electronics are able to endure the harsh environment of excavations. LDR is now embarking on extensive alpha testing of the first production intent systems, which will be tested by contractors, utility companies, and solution providers in North America, Europe, Australia, and Israel

Conclusion

LDR is intended to be used within existing one call (811) and other excavation processes and does not require changes to these processes. What it provides is a final level of damage prevention by enabling the excavation equipment operator in the field to detect and avoid utilities in real time while he is excavating.

 

This post is based on Yuval Barnea's talk at the Subsurface Utility Mapping Strategy Forum (SUMSF).

Developing a subsurface digital twin for Canada

The Canadian Underground Infrastructure Register initiative

Underground infrastructure provides the essential services that fuel our economy. During construction excavators often damage elements of this infrastructure because the location of underground cables, pipes and ducts is not well known. Underground utilities are one of the biggest causes of delays and budget overruns on public construction projects. When these utilities are damaged, people may be injured, utility services to the public disrupted, and other indirect and societal costs incurred such as traffic disruptions and loss of custom.  Making the precise location of buried infrastructure accessible to engineers, designers and excavators not only keeps people safer, but also introduces greater efficiency into construction processes.

The annual number of voluntarily reported damages to underground utilities Canada-wide totals close to 12,000.  Direct costs include the costs of sending a crew to repair the damaged pipe or cable. Indirect costs include many factors that are often hard to quantify such as traffic disruption, injuries and fatalities among workers and the public, and lost custom that local businesses experience. Damage to underground infrastructure during construction costs the Canadian economy about $3 billion annually. A large proportion of the costs of underground damage is borne by consumers, primarily through service disruptions. Return on investment (ROI) studies of improving location information about underground utilities conducted since the late 1990s have consistently revealed a large ROI, most recently $21.00 saved for every US$1.00 invested.

Six months ago an initiative to address the challenge of reducing damage to underground infrastructure was formed in Canada by Steve Slusarenko. Called the Canada Underground Infrastructure Register (CUIR) initiative its goal is to elevate awareness of the challenge of damage prevention in Canada and to develop a solution to enhance and improve the damage prevention processes currently in use. The CUIR initiative is intended to enhance current practices in a way that enables all stakeholder groups to benefit from the initiative; construction contractors, network owners, government transportation agencies, design engineers, subsurface utility engineering (SUE) engineers, surveyors, locators, workers in the field and the public. A cross-disciplinary team is being formed by reaching out to all stakeholder groups to elevate awareness of the CUIR project and achieve broad representation from the community.

To put this in context sharing maps of underground infrastructure is not new to Canada. For example, the City of Calgary's Joint Utility Mapping Project (JUMP) system, the ICI Society in British Columbia, the City of Toronto's Digital Map Owners Group (DMOG) and others have been sharing underground utility information for years.

Recently the CGA Next Practices Report to Industry argued that a comprehensive national GIS map of buried infrastructure is among the opportunities for systemic improvement with the greatest ROI for industry. The CUIR initiative has also been inspired by the progress of the National Underground Asset Register (NUAR) project currently underway in the UK. The objective of NUAR is to develop a register of location data for all underground infrastructure in England, Wales and Northern Ireland that is accessible to all network owners and government agencies.

The benefits of a national register are improved safety; greater construction efficiency; reduced design, construction, and maintenance costs; greater regulatory compliance; improved locate efficiency; fewer project delays and budget overruns; fewer service disruptions to the public; and less traffic disruptions, loss of custom and other inconveniences for the public.

Opportune time to develop a national underground registry

There are several reasons why now is an opportune time to develop a national underground registry. First, according to a recent report from the Next Practices Initiative of the Common Ground Alliance the damage prevention industry has reached an inflection point. For more than half a decade, the rate of damage to underground infrastructure in North America has increased or remained stagnant. The North American one call system has become highly inefficient and industry confidence in the system has been eroded, resulting in a process that has stalled and is not achieving its primary goal of reducing damage to underground infrastructure. Second, recent developments is several jurisdictions have shown and are showing that the barriers to the development of such as system are surmountable. Thirdly, new innovative technical developments are making to possible to detect, capture and share underground information more efficiently and accurately than ever before.

Background: UK National Underground Asset Register

One of the most important initiatives that shows that what has been the major barrier to the development of an underground registry can be surmounted is the UK's National Underground Asset Register (NUAR). This initiative grew out of a bottom-up collaboration among asset owners and organizations involved in working on and maintaining embedded asset networks in the North East of England and Central London. The foundation for two successful pilots was provided by network owners coming together to agree on a legal framework for data sharing. Each network owner remained the custodian of its own data which provided for clear accountability chains in terms of ownership, governance and regulation. Also fundamental for achieving a high level of participation among asset owners was a risk-based approach based on a high standard of data security and data protection.

Challenges to development of a national underground infrastructure register

Chief among the barriers to a national register identified by a recent CGA report is the lack of the political will to share information. For several reasons including competitive, security and liability issues in some sectors there has been industry resistance to sharing facility location information with other stakeholders. One of the important learnings from the NUAR project is that this barrier is surmountable.

It is important to recognize at the outset that the challenge in developing a national register is not primarily technical. A growing list of companies provide technologies that are being used successfully to detect existing underground infrastructure, capture location of newly installed or exposed facilities with survey grade accuracy, and record and share underground location information on handhelds in the field. The chief challenges are organization, governance, and a robust funding mechanism.

Organization

A key barrier to developing a national register identified by the CGA is the lack of a centralized, trusted organization capable of providing the governance for and implementing a national GIS underground infrastructure database. Historically, different jurisdictions have dealt with the organizational challenge in different ways.

• In North America the industry standard is a mandated one call system funded by utility owners. In Canada an option for a national register would be to build on the existing one call systems, which enjoy 100% participation by law. One call procedures are familiar to many construction stakeholders and this option would minimize the changes required from current practice.

• Private for-profit companies run one call systems across Canada and internationally private companies run underground information sharing systems in Australia, US, and Singapore.

• An industry consortium is another option. In British Columbia, the ICI Society was formed a number of years ago by utilities who voluntarily got together and agreed to share their data for use cases other than damage prevention during excavation.

• A government supported voluntary system is another option. The Scottish Community Apparatus Data Vault (Vault) was initiated in 2012 when utilities and government transportation agencies got together and agreed to share data among themselves using a computer system developed at the University of Leeds.

• In some jurisdictions, government have mandated damage prevention structures. Laws and associated regulations stipulate activities that network owners, excavators and other stakeholders are required perform during a construction project. An important motivation for mandated systems is that they achieve 100% participation.

   

The main point here is that there are different approaches to organizing the capture and sharing of information about underground infrastructure among stakeholders. The most important factor in choosing an appropriate organization structure is that it must be able to achieve 100 % participation (or as close to 100% that is reasonably achievable) among those organization and disciplines involved in capturing and maintaining underground data including utility and telecom network owners, pipeline owners and operators, oil and gas firms, government transportation and other agencies, SUE engineers, surveyors and locators. Anything less 100 % detracts from the potential value of the register.

Governance

A fundamental requirement of a system for sharing information about underground utilities is security and data protection based on an agreed open and transparent governance model. Network owners need to feel confident that the system has robust security and data protection.  This needs to be laid out in the rules of engagement as part of the legal framework agreed to by all participants. A key success factor in the NUAR project was that network owners were able to agree on a legal framework for data sharing.  Each network owner remained the custodian of its own data which provided for clear accountability chains in terms of ownership, governance and regulation.

User fees

An important question is whether users should be expected to pay for this service? User fees should be viewed not just as contributing to funding but also for their impact on achieving a high level of participation. Traditionally in North America the one call system is funded by the network operators at no cost to excavators . The NUAR project in the U.K. is currently holding a public consultation to consider several options including fees for network operators, excavators, and other users of the system.

Funding mechanism

A national underground register provides an essential public service, contributing billions of dollars to the national economy, improving the productivity of the construction industry and providing important benefits to Canadian society as a whole, and its funding model should reflect the importance of its role. In the broader context of developing a subsurface digital twin, the funding model should enable the register to address other use cases in addition to damage during excavations including emergency response, utility asset maintenance, disaster planning and response, and smart cities programs.

A national register must be a dynamic organization able to take advantage of the latest technical innovations to accelerate the development of a high accuracy, up to date and comprehensive repository of underground data. Achieving this goal requires a robust funding model that can provide support not only for operations but also to provide for innovation. 

Data quality responsibility

An essential part of any conversation about data is who is responsible for each data element. When the registry reports that the accuracy of the location of a cable or pipe is within a half a meter horizontally and a meter vertically, I need to know who captured the data, when and with what equipment and most importantly who signed off for it. If it came from a SUE survey signed by a professional engineer, I will have confidence in it, but if the data is sourced from utility records with no professional taking responsibility for it, I will have little grounds for confidence in using it. Furthermore, metadata and a sign-off by a professional enables an informed conversation about whether the newly acquired data is better and should replace the existing record.

One of the things that needs to be clarified in the context of underground infrastructure is the roles of locators, professional surveyors, and professional engineers in collecting and certifying data. For example, in Colorado and Montana it is a requirement that as-builts be signed off by a professional. In most jurisdictions SUE surveys must be signed off by a professional. Understanding the equipment used to gather information and the reliability of that technique in that particular project situation is the responsibility of the person putting their sign and seal on the data. To choose and assign the appropriate coordinate system requires a professional surveyor who will also tie that decision in with with the existing project-level coordinates or survey coordinates and make sure it all fits together for the overall project. Assigning quality levels compliant with the ASCE 38 and CSA S-250 here in Canada requires sign off by a professional engineer. In North America land surveyors and professional engineers carry insurance that is designed specifically for them in the case of liabilities.

But what is the role of locators in upgrading location data about existing underground infrastructure ? Utility records comprise the vast majority of the data we have about underground utilities and much of this data is inaccurate, out of date or simply missing (especially in the case of abandoned infrastructure and infrastructure without a known owner). It is estimated that in the U.S. over $10 billion is spent annually in locating underground utilities and other infrastructure. Most of this is routine locate operations conducted by locators, often in response to a one call ticket, but it includes locate operations such as hydro vac contracted by excavators. Currently most of this data is not recorded or shared. To enable a national registry to achieve an acceptable level of data quality will require processes to upgrade the quality of existing data. Accurate as-builts and SUE surveys will play an important part, but given the huge volume of data, it seems clear that locators are going to be key to upgrading the quality of the data we hold about existing infrastructure. To enable locators to contribute in a meaningful way to improving this data, we are going to have to look at new innovative technologies for conducting locate operations and capturing and sharing the results, potentially new qualifications and certifications for locators, and new ways of assigning responsibility for data collected during routine locate operations.

Beneficiaries

Considering the impact of a national register for underground infrastructure on the various stakeholder groups suggest that many would benefit.

• One of the big benefits of a national register is risk reduction. Evidence from the Colorado experience, where contractors participated in the initiative right from the beginning, suggests that contractors there realized significantly less underground damage and very substantial financial benefits as a result of the measures implemented by CDOT.

• Another construction stage where reliable underground location data is also essential is planning and early engineering design.  The payback on having accurate data on the location or underground utilities during planning and design is enormous. Knowing reliably where underground utilities are located avoids redesign work and utility relocations.

• In Colorado the state Department of Transportation is the agency that is responsible for regulating the public ROW which provided a basis for regulating public construction projects to achieve more on time completions, fewer budget overruns and ultimately less cost to the taxpayer.

• For surveyors and SUE engineers a national register will increase demand for high accuracy location as-builts and for high quality SUE surveys.

• For network operators a national underground register would reduce the frequency of outages, eliminate unnecessary and expensive relocations, reduce  liabilities, lower the cost of supporting locate operations in response to one call notifications and ensure greater regulatory compliance.

• A major share of the cost of underground utility damage is borne by the rate-paying public primarily through loss of service.  A national underground repository would reduce service interruptions and lower the risk of traffic and other disruptions, injuries and fatalities associated with incidents of damage to underground infrastructure. 

• For locators a national register represents a large opportunity to contribute to accurately locating and recording location data for the millions of miles of existing underground infrastructure for which existing data is generally unreliable. To do this efficiently will require familiarity with new and innovative technology for locating existing underground infrastructure. The effect of these changes should be to raise the professional profile of locators and this will be reflected in higher pay levels and reduced staff turnover.

A national underground registry would also be expected to result in lower insurance costs which would produce financial benefits for many stakeholders. Construction contracting is a low margin business and reducing insurance premiums would be significant benefit for them as it would add directly to their bottom line. Reduced insurance costs would also be expected to benefit network operators and others.

Summary

Underground utility damage is expensive economically and socially. The Canada Underground Infrastructure Register (CUIR) initiative is intended to elevate awareness of the challenge of underground infrastructure damage in Canada and to improve current damage prevention processes. Now is an opportune time to develop a national underground registry for several reasons. First, the damage prevention industry has reached an inflection point. For more than half a decade, the rate of damage to underground infrastructure in North America has increased or remained stagnant. The North American one call system has become highly inefficient and industry confidence in the system has been eroded. Second, recent developments is several jurisdictions are showing that the barriers to the development of such as system are surmountable.  Thirdly, new innovative technical developments are making to possible to detect, capture and share underground information more efficiently and accurately than ever before.

A centralized national map of underground infrastructure accessible all construction stakeholders provides systemic benefits with a large ROI for the construction industry, as well as economic and societal benefits.  To provide governance for and an implementation of a national register of underground infrastructure location data requires a trusted, centralized organization. A key criterion for choosing an organization structure is that it must be capable of achieving as near to 100 % participation as possible among utility and telecom network owners, government agencies, design engineering firms, contractors, surveyors, SUE engineers, locators and others. In North America many construction stakeholders are familiar with their state or provincial one call system which could provide the foundation for a national register that would minimize the changes required from current practice.

An appropriate funding model is required that reflects the importance of the register as an essential public service, contributing billions of dollars to the national economy and providing important benefits to Canadian society as a whole. Specifically the funding model should be able to support a dynamic organization, not only be able to support operations but also to provide for innovation.

Several capabilities are essential for making such a register effective. Open and transparent governance is a key requirement. Organizations such as utilities and telecoms who contribute and share their data need to know that the register provides a secure environment with data protection and a legal framework with agreed rules for how data is to be shared. Another is responsibility for data quality, in which professional surveyors, professional engineers and locators will play key roles.

A national underground infrastructure register would not only contribute billions of dollars to the economy, improve construction productivity and provide important societal benefits to Canadians, but it would also provide significant benefits to individual stakeholder groups: contractors, government transportation and infrastructure agencies, network owners, engineering design firms, and provide large opportunities for SUE engineers, surveyors and locators.

If you would like to get involved in the project, please contact Steve Slusarenko and we will provide materials with more details on our objectives and how we're planning to achieve them. Our goal is to enlist all stakeholder groups to help us put this together to everybody's benefit.

This article is based on the panel discussion on Developing a digital twin for Canada at the Subsurface Utility Mapping Strategy Forum (SUMSF). The Moderator was Steve Slusarenko and the panellists were Lawrence Arcand, president of 4Sight Utility Engineers, vice-chair of the CSA S-250 committee, and chair of the Transportation Association of Canada's (TAC) Public Utilities Management Subcommittee, Wilson Phillips, representing Professional Surveyors Canada and who has been working on finding a solution for managing underground infrastructure data in Canada for a decade, and Geoff Zeiss, Principal at Between The Poles, who has been following and documenting underground infrastructure data systems worldwide for 25 years.

Visualizing underground infrastructure for multiple utilities on a single map

The National Underground Asset Register (NUAR) is intended to be a comprehensive digital map of all underground pipes and cables owned and operated by 650 asset owners in England, Wales and Northern Ireland. When deployed it will provide immediate access to UK underground asset data online from handhelds and other devices to qualified excavators and their contractors.  A unique capability that differentiates NUAR from other underground data management systems lies in its ability to combine and visualize underground infrastructure of many different network operators on a single map.

Background to NUAR

In 2018 the Northumbrian Water Group Innovation Festival brought together 20 utilities, telecoms, and local government authorities in Newcastle upon Tyne to voluntarily collaborate in developing a shared underground infrastructure map showing the location of water, wastewater, gas, electricity, telecoms and other underground services provided by the network owners. Later extended to Central London, it became the pilot for what subsequently became the NUAR project sponsored and funded by the Geospatial Commission, part of the UK Government Cabinet Office.

Integrating underground data from different utilities

One key differentiator of the NUAR project is combining and visualizing underground utility data sourced from different utilities on a single map. Globally every utility has developed its own terminology for describing its network facilities, its own ways of graphically symbolizing different equipment, its own choice of base map showing road centre lines and other land base features and its own standards for network documentation.

A major advantage of mapping infrastructure in the UK is that every network operator records the location of their facilities against the same national base map, the Ordnance Survey's MasterMap. In North America in contrast every utility uses a different base map. Conflating utility data to the same base map is a complicated process which inhibits the development of a representation of underground infrastructure on a single map. In the UK the common national base map provides a foundation for displaying data from many utilities on a single base map. But to meaningfully combine and visualize data from different utilities on a single map requires that data providers agree on standards for data elements, terminology, symbology and templates for network documentation.

Developing a harmonized data model

The first version of the data model was developed in conjunction with about 40 utilities who participated in the North East of England and Central London pilots.  Fortunately the development of the Open Geospatial Consortium's open standard for exchanging underground data Model for Underground Data Definition and Integration (MUDDI) coincided with the NUAR pilot. The NUAR project became the first project to implement MUDDI in the real world.  MUDDI supports profiles that enable the MUDDI model to be adapted for different uses cases and countries. For NUAR the UK Excavation Profile was used. Participation in the MUDDI initiative enables the NUAR data model to be openly available to network operators and other organizations who choose to adopt it as a standard for their own data operations.

The central guideline that has guided the development of the model from its inception during the pilot was the need to minimize structural elements that hardwired the model. With a rapidly evolving model it was essential to be able to change different aspects the model without having to reconfigure the entire model as each new utility's data brought new changes. The result was the development of ways of modelling utility networks that differed from what had been used in previous utility models. Examples include defining general feature types that could be qualified using attributes rather than structures making them more flexible, allowing a single feature table to support multiple spatial data types (points, lines and polygons) rather than separate tables for each data type, and implementing codelists separate from the data model making it possible to change them without republishing the model.

During the initial build phase of the project each it was found that new utility data source continued to bring changes to the model. At this point it had become more essential to carefully manage changes resulting from incorporating data sets from new asset owners because of the potential impact on the data that had already been brought into the model.  

As new data is brought into the system, new feature types are discovered, for example, EV charging points, so that over time the data model is becoming more comprehensive with the potential for supporting additional use cases. In addition it is important to support the interaction of NUAR with external systems by making data types general and accessible to multiple systems and incorporating fields for capturing codes unique to the external systems. In the future this will make it possible to support work flows in which network operators' data systems provide direct data updates to the NUAR database.

One of the important realizations during the development of the Ordnance Survey MasterMap was the critical importance of object identifiers (OIDs). As new data flows in to be analyzed and brought into the NUAR model, it is being found that many asset owners have not implemented feature identifiers. One of the long term benefits of the development of the NUAR data model may be instilling in industry data modelling practice the importance of unique feature identifiers.

Progress of NUAR build phase

At the time of Amy Manefield's presentation at the SUMSF conference in March, the NUAR team had engaged with all 250 asset owners in the three initial regions of the North East of England, Wales and London. Data Exploration Agreements (DEA) had been signed with 88 of these utilities. The DEA allowed the data from these utilities to be explored, analyzed and the process of transforming it to be initiated. Of the utilities with DEA agreements 42 had already shared their data with the NUAR team and over a dozen of these data sets had been successfully transformed to the NUAR harmonized data model.

 

This post is based on Amy Manefield's talk at the Subsurface Utility Mapping Strategy Forum (SUMSF). Amy Manefield is NUAR Head of Data Operations at the NUAR project of the Geospatial Commission.

California legislation mandates reporting underground utility damage by excavators

In 2016 in the first of several far reaching regulations the California legislature passed SB 661 that created the California Underground Facilities Safe Excavation Board. The primary activities of the board were to develop standards and prescribe rules and regulations covering underground utilities during excavations. A number of other bills followed, the most important of which was SB 865 in 2020 which contains provisions with far reaching implications.

Reliable as-builts

First of all, SB 865 requires network operators operator to maintain records of the location of subsurface utilities.  Starting in January 1, 2023, all new subsurface installations are to be mapped using a geographic information system (GIS) and maintained as permanent records by the network operator. It is not clear from the legislation itself what the implications are for the accuracy of as-builts submitted for newly installed facilities, but optimistically it will result in regulations similar to those in Colorado and Montana which mandate accurate as-builts signed by a professional engineer or land surveyor.

Reporting damage incidents

In North America few jurisdiction require reporting of incidents of underground utility damage during construction. Another provision of SB 865 with far reaching implications makes reporting underground damage mandatory for excavators. The California Code of Regulations requires that an excavator causing damage must file a report at a regional notification centre within two hours of the incident. Emphasizing the importance of this data the bill further specifies that the regional notification centre must notify the California Underground Facilities Safe Excavation Board of the damage incident.

Recording information about incidents of underground damage is essential not only in developing an understanding of the causes of damage, but it also provides the basis for assessing the effectiveness of different programs for reducing damage. To put this in context in North America reporting of incidents of underground damage is generally not required.

In North America extensive damage data is compiled by the Common Ground Alliance (CGA) which receives over 400,000 voluntarily submitted damage reports every year. CGA issues a DIRT Report every year with valuable data on underground damage including the rate of damage prorated to construction activity. The California legislation should enhance the perceived value of collecting and compiling data on underground utility damage.