Between the Poles

AGC one call survey: lack of accurate utility locating by network owners weakest element

Recently the Associated General Contractors of America (AGC) conducted a survey of one call (811) underground utility safety and damage prevention processes among contractors in various construction sectors including heavy water/wastewater, highway/bridge, telecom, gas transmission and distribution, and energy infrastructure contractors. This is particularly interesting because in surveys of underground damage prevention contractors are often not heard from or are a minority of respondents.

The survey found that all of the professional excavators are familiar with their local one call system and its requirements. 

Nearly 3/4 of the respondents reported weaknesses in their one call system.  Close to 80 % identified the lack of accurate utility locating by facility owner/operators as the weakest element.  Over half reported unmarked or mismarked facilities by facility owner/operators responding to a one call notification as the most frequent cause of damages and near miss events.  Another frequent problem reported by the respondents was that abandoned facilities were seldom marked by utility owner/operators and were treated as live lines.

Is a national map of underground infrastructure achievable ?

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 the U.S.has increased or remained stagnant. The hundreds of thousands of individual damages that occur across the country each year cost the national economy approximately $30 billion annually according the the CGA 2019 DIRT report. . This includes direct costs (facility repair) and indirect costs (property damage, medical costs, loss of custom, disruption to services, and others) but does not include environmental and social impacts.

The 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. The Infrastructure Protection Coalition estimates that $61 billion in waste, inefficiency, and excess cost is embedded in the current system - this is in addition to the $30 billion cost of damage estimated by the CGA.

The CGA Next Practices Report to Industry argues that among the opportunities for systemic improvement with greatest ROI for industry is a comprehensive national GIS map of buried infrastructure. The Next Practices Pathways Status Report Report makes the case that the impacts of unreliable and inaccessible facility maps on the construction process are  great and specifically identifies planning and design without reliable underground facility maps which results in redesigns in the midst of the project, unnecessary and expensive locate request and utility relocations, and higher risk of underground damage.  Inaccurate, out of date or simply missing data also make the locating process more time consuming and more uncertain than necessary.  Furthermore, making facility maps accessible to all project stakeholders especially excavators would have significant benefits especially in improving job site safety.

The CGA report identifies barriers to creating and maintaining reliable facility maps and making these accessible to all construction stakeholders. However, recent experience and new developments have demonstrated and are demonstrating that these barriers are surmountable. 

Chief among the barriers identified by the CGA is the lack of the political will to share information.  For a variety of reasons including competitive, security and liability issues there is industry resistance to sharing facility location information with other stakeholders. The National Underground Asset Register (NUAR) project in the UK has shown that these issues are surmountable and industry can become convinced of the significant positive benefits of sharing reliable information in a secure environment with the appropriate data protection measures. For this project the high standard of data security and data protection enabled network owners to fell comfortable in agreeing on a legal framework for data sharing in which each network owner remained the custodian of its own data. This provides for clear accountability chains in terms of ownership, governance and regulation.

Another barrier is the lack of a centralized, trusted organization capable of being responsible for a national GIS underground infrastructure database. It must be able to operate and maintain a secure centralized or distributed database accessible to all construction stakeholders with data protection capabilities that is able to ensure all data custodians that their data is safe and protected. Historically different organizational structures have been successfully used to achieve this goal, including government mandated organizations (DT DICT system in France), voluntary collaborations between industry and government (Vault system in Scotland), industry associations(ICI Society in British Columbia), and others.

On the technical side a barrier is a lack of commonly agreed standards for seamlessly and automatically sharing GIS facility location data across organizations and jurisdictions on a common base map. The ASCE 38 standard for existing infrastructure has been available since 2002 and a new, greatly updated version is imminent, the new ASCE 75 standard for as-builts will be released soon.  Both of these standards have been mandated for construction in the public right of way in Colorado. The Open Geospatial Consortium's emerging MUDDI standard for exchanging underground infrastructure infrastructure (which is compatible with ASCE 38 and 75) is already being used on the NUAR project in the UK and the UNUM project in New York.City.

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. Recent developments have demonstrated and are demonstrating that the barriers to implementing such a system are surmountable suggesting that a centralized national map of underground infrastructure is feasible and would provide important economic and social benefits. For contractors a national map would reduce the risk of underground utility strikes during construction and result in more on time and on budget completions.  It would also make job sites safer and reduce the risk of injuries and fatalities for construction workers and the public. In the longer term it would reduce insurance costs which for the historically low margin contractor sector is an important economic benefit. For engineers and designers it means knowing the accurate location of underground and above ground infrastructure during planning and design and avoiding redesigns. For surveyors it represents increased demand for survey grade location accuracy for underground utilities and other infrastructure. For network operators it would reduce the frequency of outages, eliminate unnecessary and expensive relocations, reduce  liabilities, and lower the cost of supporting locate operations in response to one call notifications. For government transportation agencies it would reduce the cost of public construction projects, reduce delays and deliver more on time completions. For the public it would mean fewer service interruptions and less risk of traffic and other disruptions.  For the locate industry it would represent 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 the location of newly installed network facilities, and recording and sharing underground infrastructure information.

Reducing damage to underground utilities: the French DT DICT system

In France a national system for reducing damage to underground utilities during construction was initiated in 2013.  The key features of the system are the requirement to notify utilities with the details of a proposed construction project during the planning phase, a process that improves location accuracy of existing underground infrastructure, mandatory reporting of incidents of damage, and the Observatoire national DT-DICT which publishes annual statistics. The annual statistics include the number of projects, the number of damage incidents and the ratio expressed as a percentage of damages per project.  The statistics show that while the number of projects has increased since 2013 by about 25 %, the damage per project has decreased from 0.42 % in 2013 to 0.26% in 2020. This represents a significant decline in underground damage even though construction activity has increased.

Background

In early 2000, the French government investigated damages in utility networks, of which there are something like 60,000 incidents every year. It found that the average direct cost of each damage incident was roughly 1,000 euro, the total cost including direct+indirect+social costs was estimated to reach 32,000 euro for each damage incident, and in addition there were injuries and fatalities to workers and the public. The total cost to the French economy is estimated to be on the order to two billion euros annually. According to professionals involved in public construction project, the main causes of incidents of damage to utility networks are unreliable information about the location of underground utility networks,  lack of practical and efficient tools to measure accurate locations for underground utilities, and the inability to provide real-time visualization for underground utilities.

After many very serious accidents involving fatalities in the late 2000s, the government began an initiative entitled Construire sans détruire (Building Without Destroying.)  In 2011 this resulted in damage reduction regulations. It required the implementation of an online service where all network operators were required to  to provide information about their overhead, underground and underwater utilities including their location. Furthermore they were required to classify all of their network equipment according to three quality classes. The target class is Class A which means that the location of the network facility is known with an accuracy better than 40 cm for rigid equipment like pipes and better than 50 cm for flexible facilities like cables. Class B is assigned to network equipment whose location is known to an accuracy between 40 cm and one meter. Class C is assigned to equipment who location is either not known or is known to an accuracy of one metre or lower.  The objective for achieving the Class A quality standard for all critical infrastructure (gas, electric power, hazardous fluids and water under high pressure) in urban areas was 2020. The target for all critical infrastructure in urban and non-urban locations is 2026. The target for knowing the location of all network infrastructure in France to 40 cm or better in 2032.

The DT - DICT system

At the inception of a construction project the project manager is required to prepare a DT (Déclaration de projet de travaux) a standardized document where the construction project is described.  It can be submitted online or on paper. Among other things it involves drawing a map of the proposed construction site which can be a shape file or a sketch on paper.  Once the DT is submitted all the operating companies who own network facilities in the area, have nine days to provide maps showing the location of their network equipment with the quality level (A,B, or C) assigned to each piece of equipment. The project manager will likely receive a response from 8 -12 network operating companies including electric power, gas and fuel, clean water, waste water, telecom, and other utilities.These responses enables the project manager when planning and designing the project to know where underground infrastructure is located and the reliability of the data. Unfortunately current regulations do not restrict the way this information is provided to the project manager and they can take the form of paper, PDF or a variety of digital vector formats. 

When a project has reached the stage of excavation, the project manager must submit a second document referred to as DICT (Déclaration d'intention de commencement de travaux) declaring the intention to begin work.  The DICT provides a detailed schedule of the planned construction work. In response to the DICT the network operating companies are required to notify the excavator of any changes to the network since the submission of the DT.  They also are required to verify the technical compatibility of the project with the existing networks and check the technical safety recommendations. 

The objective of the DT DICT system is to provide the project manager with maps of all underground utilities accurate to 40 cm or better (Class A). One of key activities of the project manager is to review the quality levels assigned to all the network facilities in the construction area to identify any equipment that has not achieved Class A. For any equipment assigned B or C Class, the project manager may require additional investigation to precisely position the network equipment to achieve Class A. There are rules for who is responsible for funding the extra investigations. For equipment that is assigned Class B, the project is responsible for covering the cost of any further locate work.  For equipment assigned Class C, the network operator and the project split the cost of additional locate operations 50%/50%.  If it is suspected or revealed that the maps provided by the network operator are wrong, the operating company must perform and cover the cost of additional investigations to locate the noncomplisnt equipment accurately.

Impact of the DT DICT system on underground damage

The DT DICT system has been operational since 2013.  One of the requirements of the regulations is that it is mandatory to report all incidents of underground damage.  Based on these data statistics are compiled and published annually for the Observatoire national DT-DICT.  There are several things to notice in these statistics.  First of all construction activity has increased by about 25 % since 2013.  Secondly in 2020 most of the submissions were made online.  Only 7 % of the DT submission were manual, and these were probably made my relatively small operators.

Year	Projects	Damage rate	Submitted online
2013	4,502,440	0.42%	29%
2020	5,628,251	0.26%	93%

Since the DT DICT system was implemented, the damage rate prorated to construction activity (number of damage incidents per project) has decreased. The damage rate in 2013 was 0.42%. Seven years later, the statistics show that the damage rate has decreased to 0.26% which represents a large improvement. This contrasts with the damage rates for one call systems in the Netherlands, United States, and Ontario which have remained nearly constant for the last few years,

One of the important features of the DT DICT system that differentiates it from one call systems is that the process improves the quality of the records maintained by network operators.  That together with the requirement of notifying all affected utilities of planned construction projects are probably the most important reasons for the decline in the rate of underground damage.

Challenges

The DT DICT system places heavy responsibilities on the construction industry.  These include the preparation and management of complex documents, challenging scheduling, especially for surveyors, risk of delays, and increased demand for surveyors because of the high accuracy required by the DT DICT system.  This is occurring at a time where there is already a shortage of surveyors in France.

The challenge for surveyors is to increase productivity. One way is to avoid site visits whenever possible.  Modern technology in the form of a smartphone and GNSS+RTK makes it possible for the construction crew to record the location of newly installed or exposed underground utilities.  The collected data can be reviewed later in the office by a certified surveyor.  The new technology makes it possible for contractors and network operators to comply with the DT DICT regulations without adding significantly to costs.

The future of utility surveying is that the certified surveyor no longer needs to travel to construction sites. The location of utilities in open trenches can be recorded to survey accuracy and uploaded by the construction crew who are already onsite.  With modern LiDAR and photogrammetric technology it is possible to record a point cloud of the open trench which can be stored in the cloud and contains much more information than a traditional set of survey points.  If the location of all the underground utilities in the proposed construction site is Class A, known to 40 cm accuracy or better, augmented reality technology provides a reliable way of visualizing this data in the field on a handheld device.

This post is based on Patrice Lemire's talk at the Subsurface Utility Mapping Strategy Forum (SUMSF). Patrice Lemire is the Managing Director of Geosystems France.

Subsurface digital twins: How Singapore plans to address data quality and accessibility challenges

TThe recently published Digital Underground: Imagining a digitally enabled future is full of insights derived from a four year effort by the Singapore Land Authority in developing a road map for a coherent national mapping strategy for underground utilities and, most recently, supporting an ecosystem to produce and deliver accurate and complete digital data to stakeholders..

The recognition that the quality of the existing data about underground infrastructure represents a major inhibitor to developing a reliable subsurface digital twin is a central theme. For example, the Singapore Digital Underground document states 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."

Another challenge is accessing underground infrastructure data.  In many jurisdictions worldwide including Singapore records of the location of utility and telecom networks and facilities are often owned and maintained by private utility and telecom operators.  The result is that access to underground infrastructure data is often restricted and not available to all stakeholders on construction projects. Jurisdictions have addressed the accessibility problem through organizational structures that often involve government such as government mandated one call systems in North America and the DT DICT system in France. Systems that are not mandated by government have been developed, for example, the private one call system LineSearchBeforeYouDig in England and the industry voluntary Vault system in Scotland.

The Singapore Digital Underground project identified measures that it considers necessary to address these challenges. Current business practices for data production, data management, data sharing, and data use are largely dependent on individual land administrators, network owners, contractors and surveyors and are not consistent for all stakeholders.  The result is that every day significant effort and resources have to be invested to work around the lack of reliable information about underground infrastructure.

Data accessibility for all stakeholders

The foundation for addressing the data accessibility issue in Singapore is a new subsurface utilities data governance framework. Among other measures it provides a basis for making government and network owners' data accessible to all stakeholders. The UK's National Underground Register (NUAR) initiative has an analogous framework in the form of data sharing agreements that were signed among 40 or so utilities and government agencies during the pilots in the North East of England and Central London and enabled data sharing among all the participants.  Achieving a long term framework of this type for the nearly 700 network owners is a top priority of the NUAR implementation, currently underway in England, Wales, and Northern Ireland.

In Colorado enabling access to underground utility data initially involved requiring contractors working on public construction projects for the Colorado Department of Transportation (CDOT) to use a mobile+cloud solution developed for CDOT. The source of the data was SUE surveys and high accuracy as-builts mandated by recent state legislation and regulations. It did not include data of uncertain reliability maintained in utility and telecom GISs. Sometime later network owners with equipment and locators and others working in the state ROW were also required to use the same mobile+cloud solution providing all stakeholders on CDOT construction projects access to the same high accuracy data. 

Improving data quality

The biggest challenge with existing underground data, generally stored in network owners' utility GISs, is that the data is often inaccurate, out of date or simply missing. A key question for any jurisdiction attempting to create a subsurface digital twin is whether to rely on unreliable data from network owners' records or to create a new high accuracy database with new data, for example, from recent SUE surveys or survey-grade as-builts.

Some jurisdictions such as Vault in Scotland and the NUAR initiative in the UK rely on the network documentation captured and maintained by network owners. Utilities have processes for updating and improving the quality of their data. These are supplemented by the NUAR application support for feedback from the field - implemented as "observations" in the online application developed by the Ordnance Survey for the pilots.

Other jurisdictions such as Colorado have decided not to rely on utility and telecom GIS data but to build new high accuracy databases using the results of recent SUE surveys and survey-grade as-builts with known quality levels, defined by ASCE 38-22 and ASCE 75-22.

Singapore has had a contractual standard for survey-quality as-builts since 2017. The key provisions of the new data governance proposal are designed to improve data quality and to establish an authoritative single source of truth.  Specifically it introduces the concept of a national Data Quality Hub which is comprised of a consolidated underground infrastructure database and data flows that are designed to co-exist with Singapore's current utility data workflows but which enforce data quality management.  The Data Quality Hub requires the digital submission of all newly captured data on subsurface utilities, quality control of submitted data based on a common set of rules, and the consolidation and integration of newly collected and legacy data for legacy data quality improvement. 

Integrating new high accuracy data with legacy data

For jurisdictions with new sources of high accuracy data from new legislation and regulations that are developing high accuracy databases, a crucial question is whether to attempt to integrate the unreliable data from network owners into these new databases.  In Colorado, the data from the mandatory SUE surveys and high accuracy as-builts with assigned quality standards based on ASCE 38-22 and ASCE 75-22 that goes into the new database is also made available to network owners who can use it to correct and update their records, but are not required to.

Singapore's approach is to require all data going into the Data Quality HUB to pass the set of quality rules defined by the new data governance framework.  If combining legacy data with new data, for example, from SUE surveys or from surveys of recently exposed underground utilities, results in data that can pass the quality rules then it is expected that that data should be eligible to be integrated into the Data Quality Hub.

A second challenge is that most legacy data is 2D and does not include depth or elevation.  The Singapore Digital Underground project attempted to address this issue by suggesting several ways of generating 2.5D data from legacy 2D data, but none of these is capable of producing the reliable data that the quality rules would seem to require.

Conclusion

Singapore has recognized the implications of the problems resulting from inaccurate, outdated and incomplete maps of underground infrastructure and adopted a comprehensive approach for addressing data quality and access issues. Because of the approach that Singapore has adopted and the fact that the Digital Underground project has actively engaged the international community, many international jurisdictions are watching closely as Singapore moves into the implementation phase.

Challenges of subsurface digital twins

The subsurface is composed up man made infrastructure; utility, transportation, and other infrastructure and the natural environment comprised of geology and geotechnical properties of the subsurface. A comprehensive subsurface digital twin requires a digital twin of underground infrastructure and a geology digital twin.

Digital twins of the underground infrastructure; utilities, communications, and transportation networks and other infrastructure, of cities, regions and nations have become a priority for many jurisdictions around the world. Over the past decade the emphasis has been on above-ground models, primarily because of the availability of technologies for efficiently capturing high accuracy location data for above ground infrastructure. However, many jurisdictions are recognizing the critical importance of below ground infrastructure and are integrating subsurface infrastructure into their digital twins.

Geological information, such 3D models of geological and geotechnical properties, and borehole databases, comprise an information product that has not yet reached its anticipated level of usage. Geological information has the potential to be useful in a wide range of broad use cases such as city planning, infrastructure construction projects, geohazard identification, environmental impact assessment and the development of water supply facilities, but to date this has not become standard best practice in these application areas. However, there is growing awareness of the importance of subsurface geology (in general but also to the technology used to detect and locate underground infrastructure) and it is expected that in the near future geology digital twins will be recognized as a foundation digital twin equally important to infrastructure digital twins.

Subsurface infrastructure digital twins

Digital models of underground infrastructure is characterized by important distinguishing features that differentiate them from above ground digital models and that need to be taken into account when maintaining and using models of underground infrastructure. These fall into the general categories of fitness for purpose, data quality, and accessibility.

Many cities, for example, Rotterdam, Helsinki, Pilsen, Athens, Rostock, Berlin and London to name a few, regions, such as Flanders, and nations such as the Netherlands, Estonia, Singapore, and the UK are developing 3D geometric models as a basis for digital twins. 3D models of above-ground infrastructure include buildings, transportation networks, parks, and other infrastructure typically captured in 2D or 3D imagery from overflights or in 2D GIS maps. But for a number of reasons underground infrastructure is often neglected, even though it is recognized that water and wastewater, energy (gas, electric power, and district heating), and communications (fibre and copper) networks provide the life blood of the city.

There is now a consensus that modeling a city requires not only information about buildings and transportation networks, but also about the utilities and communications networks. Utility and communications network operators maintain extensive records of their assets, including the location of their assets and operating, inspection, and maintenance data. For years they have used monitoring, control and simulation software for tracking and modeling demand, network energy, water, and gas flows, voltage, and pressure and other features of the modern utility networks. Utilities are expanding this capacity and moving in the direction of digital twins that can represent the entire utility system.  Ultimately this will enable them to support digital twin use cases that extend beyond utility asset management and network simulation to incorporate models of the entire utility network including demand and the supply chain. Digital replicas of energy infrastructure  makes it possible to undertake energy network sizing and routing process analytics to help understand and appraise loads and design optimum energy networks based on actual demand, consumer services and evolving technical solutions. In the UK electricity and gas networks operators have launched a National Energy Systems Map (NESM), a proof-of-concept project that brings together network data from all of Britain’s electricity and gas network operators into a digital, whole-energy system map covering Great Britain. The objective of the pilot project is to give customers information about energy network assets, where those assets are located as well as who owns them and is intended to provide the basis for a digital twin of the UK's energy network.

5G is increasingly recognized as an essential national utility. Knowing the location of all infrastructure is critical to understanding where fiber optic cables and 5G antennae intersect with the people and places that need them. This presents a major challenge because many telcos do not have current, comprehensive data on overground and underground assets in an integrated, easily accessible and shareable format. Operators need comprehensive, accurate and current location-based information on underground fiber-optic networks in relation to all the critical services that depend on them.  This will require integrating live data from all assets in the field with the demand for services from customers.

Challenges of subsurface infrastructure

There is a fundamental difference in what jurisdictions are able to do with representations of above and below ground infrastructure. Above ground, whatever can be photographed or scanned in the public space; from the street, from an airplane or drone, or from a satellite, in 2D or 3D, is generally unrestricted in application.  It is necessary to remove recognizable people and vehicles for privacy reasons and there may be national security restrictions, but in general this data can be used without restriction to create an open, publicly available digital model or digital twin.  The accuracy of the above-ground data in digital twins is generally high - for digitally LiDAR scanned data accuracy even reaches the mm level.

Underground the situation is different. First of all, there are restrictions on access to underground infrastructure location data.  In many jurisdictions some or all of the underground infrastructure in the public right-of-way is privately owned.  Where cities own water and sewer services, this data may be open and publicly accessible, but electric power, gas, and telecom are often privately owned and private ownership imposes restrictions on public access to this data. For example, the City of Rotterdam has decided that a key requirement of its digital twin is open access to the public. But for underground infrastructure the city has had to recognize restrictions on access. About 2/3 of the underground utility data is open and accessible, but there are access restrictions on the remaining 1/3 because these represent privately owned facilities.

Another major challenge in most jurisdictions is data quality. Utility network documentation and records are not collected or maintained consistently, the level of accuracy varies, data is often out of date and for abandoned infrastructure frequently missing. Over the past decades electric, gas, water, and telecom utilities have poured millions into digitalizing the graphic design/work management and GIS/records management processes. But the decades-old as-builting process remains marred by manual paper-based processes that results in low data quality and which has ramifications for the construction industry and for society in general. One of reasons for low data quality of network documentation is that utility business models provide no direct incentives to improve their data at the scale required for a full solution. This is a complicated problem that may require government involvement through regulation, changes in industry best practices and new technologies. Jurisdictions such as Colorado, Montana, and Singapore have implemented regulations focused on improving data quality. New technologies such as reality capture with LiDAR or a handheld phone together with RTK and other technologies for accurate positioning and mobile+cloud solutions for capturing and sharing data in the field are enabling real-time high accuracy data capture during construction.

Return-on-investment studies of improving information about underground infrastructure

Return on investment (ROI) studies of the benefits of improving the mapping underground infrastructure on highway construction projects conducted since the late 1990s have consistently revealed a large return-on-investment. A U.S. Department of Transportation sponsored survey conducted by Purdue University in 1999 of quantifiable and qualitative savings estimated a total of US$4.62 in avoided costs for every US$1.00 spent on accurately locating underground infrastructure. Although qualitative savings (for example, avoided impacts on nearby homes and businesses) were not directly measurable, the researchers made the case that those savings were significant, and many times more valuable than the quantifiable savings. In 2007, the Pennsylvania Department of Transportation commissioned Pennsylvania State University to study the savings on Pennsylvania highway projects and found a return on investment of US$21.00 saved for every US$1.00 spent for SUE when elevating the quality level of subsurface utility information using SUE. This significantly higher return on investment when compared to Purdue study is the result of maturation of process and a consideration of some of the qualitative savings in the Purdue study.

Fitness-for-purpose for subsurface utility models

Straits Times

For underground utilities the Open Geospatial Consortium's MUDDI underground standards project has identified important use cases for underground infrastructure location data including planning, reducing underground utility damage during construction, construction efficiency, asset management, emergency response, and disaster planning. Each use case has specific data requirements. For example, the planning use case may not require survey-grade location accuracy, it may only be necessary to refresh the data once or twice a year, and the level of detail may be low. Fitness-for-purpose for each use case will determine the quality of the data to be fed into the digital twin, the algorithms that model urban processes, the simulations that need to be supported and the analytics and visualization technology that makes the model cognitively easy and accessible to users.

The Netherlands, Helsinki, and Singapore have developed master plans for the subsurface that support multiple use cases. As an example, a number of years ago Singapore recognized the urgency for a map of its underground utilities for a number of purposes; planning, design, construction, ownership and maintenance of underground infrastructure. The Singapore Land Authority (SLA) initiated the Digital Underground project aimed at establishing an accurate, current, and complete map of subsurface utilities in Singapore that could be used for multiple use cases.

Priority use cases for subsurface utility models

However, the priority use cases for subsurface digital models in most jurisdictions are reducing underground utility damage during construction and construction efficiency. The simple reasons for this are economic. The cost of damage to underground infrastructure during construction amounts to tens of billions of dollars every year, injuries and fatalities of workers and the public, and delays and budget overruns on civil engineering construction projects. For this use case data accuracy, currency and completeness are essential requirements. Another issue specific to underground infrastructure is integration. In general each utility and telecom has a different data model, vocabulary, symbology, base map, standards for layout, and data protection guidelines. To integrate data from multiple organizations requires harmonizing these features in a common standard agreeable to all data providers.

Thus current geometric models of underground infrastructure will require important changes to enable them to be used as a basis for a subsurface digital twin. Digital twins are living models and need to reflect the changes in real time of the underlying assets. The key is to integrate live data from all subsurface assets and ensure that the geospatial systems modelling these networks share a common standard and are a ‘living document’ constantly drawing on current data and intelligence from the field. Databases of real time, high precision underground infrastructure data compliant with an agreed on standard are required. This requirement and new technology advances are driving fundamental changes to how data about underground infrastructure is captured and maintained.

A user platform for digital twins of underground utility infrastructure

The foundation for digital twins of cities, regions and nations are digital geometric models.  Developing these models have become a priority for a number of jurisdictions around the world. To date the emphasis has been on above ground models, primarily because of the availability of a variety of technologies for efficiently capturing high accuracy location data for above ground infrastructure. However, there is growing awareness of the critical importance of below ground infrastructure.  Several jurisdictions are integrating below ground infrastructure into their digital models.  Models of underground infrastructure are characterized by important distinguishing features that differentiate them from above ground digital models and that need to be taken into account when maintaining and using the geometric models. Digital twins are living models and need to reflect the changes in real time of the underlying assets. An on-line platform that that has been used primarily in large-scale simulations and games has a number of unique features suited for digital twins by enabling data providers including construction workers in the field, developers and users of analytics and simulations and citizen users to collaborate in real time in maintaining and using subsurface digital twins.

Background

Many cities (Rotterdam, Helsinki, Pilsen, Athens), regions (Flanders), and nations (Netherlands, Estonia, Singapore, UK) are developing 3D models as a basis for digital twins.  3D models of above-ground infrastructure include buildings, transportation networks, parks, and other infrastructure typically captured in 2D or 3D imagery from overflights or in 2D GIS maps. But for several reasons underground infrastructure is often neglected, even though it is recognized that water and wastewater, energy (gas, electric power, and district heating),  and communications (fibre and copper) networks provide the life blood of the city.

There is a fundamental difference in what jurisdictions are able to do with representations of above and below ground infrastructure. Above ground, whatever can be photographed or scanned in the public space; from the street, from an airplane or drone, or from a satellite, in 2D or 3D, is generally unrestricted in application.  It is necessary to remove recognizable people and vehicles for privacy reasons and there may be national security restrictions, but in general this data can be used without restriction to create an open, publicly available digital model or digital twin.  The accuracy of the above-ground data in digital twins is generally high - for digitally LiDAR scanned data accuracy even reaches the mm level.

Underground the situation is different. Typically there are restrictions on access to underground infrastructure location data.  In many jurisdictions some or all of the underground infrastructure in the public right-of-way is privately owned.  Where cities own water and sewer services, this data may be open and publicly accessible. But electric power, gas, and telecom are often privately owned.  Private ownership imposes restrictions on public access to this data. Accessing the data requires a legal data sharing agreement between the utility or telecom company and an entity requiring access to the data. For example, the City of Rotterdam has decided that a key requirement of its digital twin is that it is open and accessible to the public, but for below ground infrastructure there are restrictions.  About 2/3 of the underground utility data is open and accessible, but for the remaining 1/3 there is restricted access because these represent privately owned facilities.

Another problem specific to underground infrastructure is that in general each utility has a different data model, vocabulary, symbology, projection, base map, standards for layout, and data protection guidelines and harmonizing these for a shared underground utility map requires collaboration among data providers.

Jurisdictions such as the City of Rotterdam, Estonia and the U.K. are already developing geometric models that include underground and above-ground infrastructure.  For underground utilities the Open Geospatial Consortium's MUDDI underground standards project has identified important use cases for underground infrastructure location data.  The priority use cases are reducing utility damage during construction and efficiency of planning, engineering design and construction.  Other use cases include emergency response, disaster planning, and strategic planning for smart cities. Each use case has different requirements for data access, quality, currency and level of detail.

Existing databases of underground geospatial data, most of which were developed and are maintained by utilities and telecoms, are not suitable as geometric models on which digital twins can be based for a number of reasons. They are comprised of a 2D topographic map, typically with road centre lines, water bodies, building footprints and other recognizable features. Utilities either use a national base map, such as MasterMap in the UK, or have acquired a base map from a commercial mapping company. In North America in general each utility has a different basemap on which the location of utility infrastructure is superimposed. Transferring underground location data to a different base map can be a complicated process (conflation). Furthermore, each utility uses its own terminology and has developed its own data model and symbology for its displaying infrastructure maps. Most underground infrastructure data is 2D and lacks depth coordinates. Access to utility infrastructure data is generally restricted to the utility's own staff and contractors. In addition the accuracy of the data is low. It is low precision, often incomplete, and out of date. It is cumbersome to use in the field and is unintelligible to non-engineering stakeholders.

These current geometric models of underground infrastructure will require important changes to enable it to be used as a basis for a digital twin. Databases of real time, high precision underground infrastructure data are required and this is motivating fundamental changes to how data is captured and maintained. Live updates during construction and 3D reality capture with survey-grade precision are essential. Technologies that enable near real time precision data capture include LiDAR scanners, photogrammetry using handheld devices, ground penetrating radar and other underground remote sensing technology, with high precision GNSS using a base station or RTK. Being able to simultaneously capture above and below data facilitates connecting above ground visible features such as manholes, drains, risers, gas connections, hydrants, and so on with below the ground equipment. The database includes all planning, engineering and construction documents and support the integration of geospatial data from sources such as GIS, CAD and BIM.

User platform for subsurface digital twins

A platform specifically for data providers and users of a subsurface digital twin has been developed that is intended to be used after a comprehensive underground utility digital model has been built. It is not intended for the creating and building the geometric model or for new designs. It supports importing digital building and infrastructure models and provides tools for multi-user collaboration to maintain those models and keep them up to date whenever there is a change, as a result of maintenance or if there has been damage. A key requirement for this platform is scale-ability, it must support a large-scale 3D environment on the scale of a city. The amount of 3D data is growing exponentially driving a requirement for tools that will allow massive volumes of 3D data to be manipulated and visualized. The new generation of engineers are familiar with and expect three dimensional virtual environments, whether it's gaming or simulation software. Within the next 10, 20 years, they will be the ones who manage this infrastructure, so providing them with an interactive 3D environment including mixed reality where they feel comfortable provides them with an environment that best enables their skills, has to be undertaken now, because building out digital twins in three dimensional view is going to take years. 

The platform does not limit the number of simultaneous contributors who could be construction workers on the ground who want to update the model, city planners and managers running analytics and simulations, and citizen users who want to visualize and understand the results of the analytics and simulations. For all users the platform provides the most up-to-date and accurate information to enable workers to use it in near real-time. It can connect to live feeds from IoT sensors in the field to be able to monitor conditions in real-time.   Data is versioned to enable tracking changes in the data over time. The platform provides an interactive environment supporting mixed reality applications.  It runs in the cloud where it is universally accessible in a fully protected, secure environment. In addition data protection rules protect data custodians and prevent viewing of network information that could provide competitors information about a company's network.

Building a persistent environment is extremely important, because every participant, whether a user or a data provider, needs to be able to contribute to growing the environment and seeing in real time what everyone else is seeing. For example, if a telecom company begins installing a new fibre cable and at the same time the local water company is looking at that model when designing a new water pipe, the water designers will be able to see the new fibre cable in near real time. Being able to see edits in real-time makes it possible to edit the model with several users collaborating simultaneously.  Everyone can see everyone else's changes and conflicts can be avoided.  Some utilities are collecting point clouds captured with LiDAR or photogrammetrically of newly installed equipment before covering the trench and these can be used in a mixed reality environment to maintain and make modifications to existing infrastructure.

The benefits of a living digital model are better and faster decision making.  According to the CEO of one Swiss multi-utility company, not knowing exactly where the pipes are means that "As soon as we start digging, about 90% of plans have to be thrown away or redrawn, because we find stuff we didn't know actually existed underground." This refers to Switzerland where there is a very rigid replacement cycle requiring about 3% of roads to be replaced and refurbished every year, but even with this they are still missing quite a lot of information. A reliable, up to date model allows you plan for maintaining or replacing existing infrastructure, precisely where there is free space to avoid unnecessary relocations and avoiding disruptions to existing infrastructure that is delivering vital services to the communities. Better planning means fewer disruptions of services to the public. Better planning also results in faster project startup, fewer and less extensive utility relocations during construction, fewer injuries to workers and the public, fewer project delays and more on time and on budget completions for construction projects. Over time this produces substantial cost and time savings. Reduced risk of utility damage also has indirect benefits. For example, it can lower insurance costs.  A scaleable, 3D platform with high precision, real time data can also support other use cases such as proactive equipment maintenance, disaster planning, emergency response and other things that can improve the resiliency of infrastructure. Such a platform supporting users of a subsurface digital twin will minimize the impact on the local communities from any kind of disruptions that are potentially going to interrupt services.

Digital twins of underground infrastructure are living models of real world objects and require a platform and tools that enable a large number of data providers and users including construction workers in the field, developers of analytics and simulations, and citizens to collaborate in maintaining and using the models.  The key is to integrate live data from all assets and ensure that the geospatial systems modelling these networks are a ‘living document’ constantly drawing on current data and intelligence from the field.

This post is on Alex Shalash's and Antoine Castel's talk at the Canadian Underground Forum (CUF). You can listen to all the talks at CUF on the GeoIgnite CUF Youtube channel.

Digitalizing the as-builting process essential for accurate underground utility mapping

Over the past decades electric, gas, water, and telecom utilities have poured millions into digitalizing the graphic design/work management and GIS/records management processes. But in spite of this the decades-old as-builting process remains marred by manual paper-based processes that have ramifications for industry and society in general. As-builting is characterized by inefficiency that causes critical processes such as outage restoration to require more time than they should and low data quality which leads to incomplete, out of date and inaccurate underground utility records that are responsible for frequent construction delays, injuries and fatalities for workers and the public, and a drag of billions of dollars on national economies.

Dated, paper-based as-builting workflow

One of the biggest and most persistent problems for almost all utilities is the use of paper in the construction as-builting process.  It is a challenging problem that has been with us for decades.  The first post of this blog in February, 2006 discussed this problem and in some respects the as-builting workflow has not changed that much since then.  Over the past decades utilities have spent millions of dollars digitalizing design (CAD) and records management (GIS), but the gap between them has remained filled with paper. The schematic shows a typical design, construction to GIS workflow that's in place at most utilities today. Design is done using a graphic work design system (CAD) in the office that is integrated with a work management system. A paper job packet is sent to the construction crew in the field who attempt to follow the design drawing. More frequently when contractors take the design drawings out into the field, they often find that obstacles, such as existing utilities or other infrastructure even old tram lines or sewer lines, force them to make changes.  After completion of construction paper as-builts are prepared that make their way back to the office to be entered manually into the records system typically a GIS. If the construction crew has had to make some changes, these are supposed to be redlined on the design drawing, but all too frequently the crew simply hit the easy button and check the box that says, "We built it exactly as you designed it." The reality is that 90% of designs change in the field and the changes are rarely recorded. This is a major source of data quality issues and is the chief reason for the general unreliability of utility GIS records. Unreliable underground records lead to construction delays, budget overruns, injuries and even fatalities for workers and the public. 

The as-built workflow is also fraught with inefficiencies because many of the processes are manual.  The result is massive mapping backlogs. Backlogs of 30, 60, 90 days from construction complete to being entered in the GIS are common. The result is that the utility GIS is always out of date and critical processes such as outage resolution require more time than they should. 

If we are to address these issues it is imperative that we improve the way buried assets are designed, constructed, recorded, and managed.

Grid modernization is driving change

As a result of being asked to do many more things than in the past, the grid is being transformed from a centralized to a distributed model. For electric utilities, utility digital transformation is already driven by increased demand for distributed energy resources (DER) such as solar, wind and other renewable technologies. This creates a requirement for an advanced distribution management system (ADMS) which is the intelligence that supports the new distributed smart grid model. These developments are being accelerated due to COVID-19 and the requirement for a more touchless environment for utilities. The bottom line is that for these advanced solutions to provide full value a reliable digital twin of what is out in the field is essential, and right now for most utilities that remains a challenge.

Grid hardening to increase resilience is another major initiative that is contributing to transforming the grid.  When a utility experiences a major storm, flood, catastrophic wildfires, or other natural disaster it has to change its infrastructure plans.  It may have to move overhead wires underground, move transformers out of flood zones, or ameliorate the risk to substations.  The sheer glut of aging infrastructure replacement programs is also increasing pressure on utilities and contributing to a significant increase in construction activity. Grid transformation on this scale with the sheer volume of new construction that it required is forcing utilities to find ways improve productivity by managing construction data from source to consumer digitally.

As-builting remains a persistent problem

However, a major source of construction inefficiency remains. Why, after decades of growing awareness of the inefficiency and data quality issues associated with the traditional as-builting workflow, are construction as-builts still recorded on paper ? First of all, there's resistance to change. Utility construction is managed using a variety of manual, paper-based processes that have been in place for decades. Secondly, there's the aging construction workforce that has always relied on legacy processes and has not seen reason to change. Another problem is that well-established enterprise systems such as asset management and GIS don't provide the comprehensive solution that construction crews need to digitalize the full process. Those systems are designed to support long cycle construction projects which typically require a month of planning and may not be completed for six, nine, or twelve months. 

An important factor that makes this problem so persistent and difficult to resolve is the many personas involved. The as-builting workflow is tasked with taking highly technical engineering output from the designers, translating it into instructions that a construction crew can use to safely build the job to code and to standard, then asking a field engineer to draw up the as-builts, and converting those paper drawings into geospatial data that a GIS technician can use to update the utility GIS. Technically this is a complex process that involves distinctly different personas that work in different teams with different technical vocabularies, different training, different software systems, and who are measured by different goals and performance indicators. It is further exacerbated by a lack of clarity as to who owns the as-builting process, engineering, construction, or records/GIS. The designer may point to the contractor as the owner. The contractor might think the GIS technical team is responsible and records/GIS group may think that the designer owns it. Often the real answer is that no one owns as-builting and that is the operative reason the problem has been so persistent for decades.

Digitalizing the as-builting workflow

To improve the efficiency and data quality of the as-builting process digital tools are required to help utilities bridge the gap between the design and the system of record. The key technologies making this possible are mobile applications and mobile devices, cloud technology, and the availability of economical high accuracy GPS. To be successful the tools need to be adapted to the different personas. For the construction crew end user persona a mobile first philosophy is essential to enable real-time data capture in the field. This requires easy to use mobile apps supplemented by high accuracy GNSS and devices such as bar code scanners.  Together these make possible the efficient capture of survey grade data and associated metadata greatly enhancing the speed, accuracy and fidelity of the data feeding the utility systems. In addition a digital data stream makes it possible to update the system of record more rapidly.  This result is the records/GIS to become more effective in producing reliable as-built records that locate and construction crews can rely on.  For utilities that have adopted this approach, enabling field crews to digitally capture construction data is now a best practice.

Example: Digitalizing the mapping of underground duct banks

As a real world example a contractor serving some of the largest utilities in the West Coast of the U.S. was faced with new requirements for the construction project they were working on for a utility customer.  They were now required to capture GPS locations real-time during construction.  Precision was required to be two-tenths of a foot (2.4 inches) or better and location data points were to be collected every 25 feet for linear assets. The contractor had not had to meet requirements like this before on a major project. The scale of this project made the new requirements even more challenging; 35 sites throughout the Central Valley of California, 35,000 feet of trenching, auger bores under highways and railroads, and many primary enclosures.

Fortunately the contractor had had experience with digital construction processes on smaller projects. Based on their previous experience, they were convinced that a member of their own construction crew already on site could capture the location data with the required precision. Having in-house capability for capturing survey grade construction data would allow them to deliver the data without having to have a survey crew on-site or managing outside survey crews. The benefits they hoped to realize were cost savings associated with not having to hire an outside survey crew and related intangibles such as not having to coordinate schedules for survey crews and holding up construction while waiting for survey crews to arrive. However, they were concerned that the the additional training and work load required to capture location data could potentially disrupt their construction crews' schedules.

Key project achievements of digital construction workflow

The implementation of the digital workflow by construction crews actually proceeded rapidly. Crews were capturing survey grade GPS data within days.  Over a period of six months using the solution at 23 active construction sites, over 16,000 feet of buried linear assets, including duct banks and tracer wires, were mapped and some 5,000 supporting photos along the way were captured. The median GPS accuracy of the data captured by their construction crews was 0.14 feet, a remarkable achievement that exceeded the project precision requirement.  Their customer even requested them to go back to pothole and capture accurate locations for trenches that had already been covered over before they began using the new digital process. The many photos that were collected along the way and geotagged to specific locations provided a valuable record of everything that was done in the field for future reference.

Benefits of digital construction workflow

One of the important results of the project was that their initial concern that digital capture in the field by construction crews might disrupt the crews' daily routines never became a problem. Construction crews were able to collect as-built data from open trenches using mobile devices with high accuracy GPS without disrupting their normal processes or impacting their schedules. An important cost benefit was that they didn't have to employ and coordinate survey crews.  Instead of calling in a survey crew they were able to employ one of their own crew members who was already on site to capture survey grade location data. This resulted in an estimated project time savings of around 20%.

An important advantage of the the digital construction process they used enabled them to spot when crew members' shots did not achieve the required project precision. The ability to identify and flag data that exceeded the 0.2 foot accuracy requirement and needed to be repeated was an important factor in achieving the overall project precision goal. Flagging low precision data also avoided the costly process of having to send a vac truck out after the trench was filled to do potholing and retaking shots. Another benefit was automated close out enabling them to receive automated data exports without having to do any paperwork.

The major achievements of digitialization were that survey grade as-builts could be captured in near real time with no disruption to construction crews' schedules, the utility GIS rapidly updated and able to provide up to date, high accuracy underground utility records and all of this at lower cost. Overall the project realized an estimated cost savings of around 50% mainly because fewer man hours were required.

This post is based on Danny Petrecca's talk at the Canadian Underground Forum (CUF). You can listen to all the talks at CUF on the GeoIgnite CUF Youtube channel.

Major advance in capturing survey-grade location information for exposed underground utilities

A major gap in the construction process is the unavailability of reliable information about the location of underground utilities for civil engineering construction projects such as highways, railways and pipelines. Mapping underground infrastructure is benefiting from accelerating innovations in technology in detecting, locating, capturing and sharing subsurface utility location data. Mobile + cloud solutions have been developed that replace the traditional error-prone and slow paper-based workflows with near real time digital processes that result in complete, accurate and up to date records of the location of underground utility infrastructure. Mobile + cloud solutions have been adopted by a variety of stakeholders in the construction industry including engineering firms, contractors, professional locators, and government transportation agencies. 

Surveying exposed utilities

Capturing survey-grade location data for underground utility infrastructure requires that the utilities be exposed (corresponding to QL A of the ASCE 32 standard.)  For newly installed utilities this requires the survey to be conducted while the trench is open.  For utilities exposed as  as part of a SUE survey (Colorado and Pennsylvania mandate subsurface utility engineering surveys (SUE) during pre-construction), each facility must be surveyed as it is exposed. Similarly for facilities exposed during excavation. For utilities targeted for relocation or other treatment, the facility must be surveyed after it has been relocated and before the trench is filled. For a large construction project there may be  a survey crew on site that would be available to conduct these surveys, but in general, calling a survey crew for these types of surveys is uneconomical.

A key feature of mobile + cloud solutions is the ability to capture survey-grade location information about newly installed utilities, utility infrastructure exposed as part of a SUE survey or utility facilities exposed during excavation in real time. Instead of calling a survey crew a widely used alternative made possible by the availability of modern GPS/GNSS technology is to have a technician in the field use a GNSS RTK receiver to capture the location of utility equipment. GNSS receivers are already an established method of precise positioning, but they have limitations. They cannot be used in areas where facilities are inaccessible or metallic pipe is exposed. The development of GNSS rovers with integrated inertial measurement units (IMUs) that are self-leveling, not affected by magnetic disturbance, and don’t require calibration has broadened the range of application for these devices. The first GNSS rovers required that the receiver, typically attached to a pole, be positioned vertically over the facility whose location is being measured.  The next generation of RTK receivers supported tilt, making it possible to record a survey-grade location when the pole with the RTK receiver was not vertical.  However, the pole has to be in proximity to the facility being surveyed. Facilities that are not physically accessible or are too hazardous to access cannot be surveyed with this technique.

Visual Positioning

At the Canadian Underground Forum, Simon Pedley of Leica Geosystems described a remarkable GNSS RTK rover that makes it possible to capture accurate points from a distance with images. The new GNSS RTK rover (GS 18 I) expands the sensors in the device to include a camera.  The camera makes it possible to do visual positioning - capturing hundreds of measurements at survey-grade accuracy, simply by taking images of the area of interest. With this device a technician can simply record images while walking alongside an open trench or take a photo of an exposed facility during a SUE survey.  Later in the office survey grade location measurements can be made from the images captured in the field. Since imagery captured in the field represents a permanent record, return visits to a site can be avoided simply by making additional measurements from the captured images. 

The ability to capture accurate points from a distance means that whether near an open trench or at the location of an exposed asset a field worker can safely and efficiently capture the location of previously inaccessible points and points that were hazardous to access.   Even for surface features it provides a much safer way to measure locations.  For example, a technician can be on the sidewalk safely taking pictures of man holes in a busy roadway.  GNSS with visual positioning can also be used in conjunction with 3D laser scanning and ground penetrating radar (GPR) to accurately locate remote-sensed underground utilities reducing the need for vacuum and hydraulic excavation.

Visual positioning not only expands the range of points that can be safely and efficiently accessed, but creates a permanent record.  Additional images can be captured as changes are made creating up to date as-built documentation with real-world condi­tions that will reduce risks and costs later on.

This post is based on Simon Pedley's talk at the Canadian Underground Forum (CUF). You can listen to all the talks at CUF on the GeoIgnite CUF Youtube channel.

Mobile + cloud solutions are revolutionizing the capture and sharing of reliable underground infrastructure location data

A major gap in the construction process is the unavailability of reliable information about the location of underground utilities for civil engineering construction projects such as highways, railways and pipelines. All states and provinces in North America have one call legislation designed to reduce underground utility damage during construction, but statistics show that in North America damage to underground utilities is increasing. Japan and Heathrow International Airport are two examples where comprehensive approaches to reducing damage to underground infrastructure have been implemented and statistics have shown that damage has been dramatically reduced.  In 2013 France implemented the DT DICT system which statistics reveal is reducing underground damage by 2% per year.

Mapping underground infrastructure is benefiting from accelerating innovations in technology in detecting, locating, capturing and sharing subsurface utility location data. Experience has shown that enabling these technical advances to permeate and transform business practices in the entire construction industry requires government intervention. Recently several jurisdictions around the world have undertaken initiatives to collect and integrate underground infrastructure location data and make it available to all construction stakeholders. The key stakeholders in public civil engineering construction are government transportation agencies, utility and telecom network owners and operators, professional locators, engineering consultants and construction contractors. Among the leaders in this effort are the Vault system in Scotland, the National Underground Asset Registry (NUAR) project in the UK, Singapore's Digital Underground initiative, and the State of Colorado. While the UK and Singapore are in the initial stages of implementation, Scotland implemented the Vault system beginning in 2012.

Colorado has recently enacted legislation and is in the process of implementing regulations and systems that are transforming the collection, integration and sharing of underground infrastructure location data for public civil engineering projects in the public right of way with the objective of creating a digital twin of the infrastructure in Colorado's right of way. A key component of this effort is a mobile + cloud solution that enables the capture and sharing of underground location data among all construction stakeholders owning facilities or working in the public right of way..

The challenge: incomplete, inaccurate and out of date underground location data

To provide context for understanding the challenge of reliable information about the location of underground utilities, this image shows what you would see if you removed all the pavement on a downtown New York street. Removing pavement on Bay Street in Toronto or Howe Street in Vancouver would reveal the same spaghetti bowl of utilities and pipelines that have been haphazardly slapped into the ground over many decades.

Utilities and telecoms have attempted to capture the location of this infrastructure in the form of records, originally paper and now often managed in a GIS.  Records are generated by a flawed process based on paper as-builts. The original planning and design documents for underground utilities are paper drawings created with CAD software. But where utilities actually go into the ground and where they were planned to go in the ground are often very different.  First of all, the designers planning routes for new utility installations don't have access to reliable location data for existing utility infrastructure.  When the contractors take the design drawings out into the field, they often find that obstacles, such as existing utilities or other infrastructure like old tram lines or sewer lines that force them to trench in another location.  Furthermore contractors get paid based on how rapidly they get the new facilities installed so there is a tendency to take the path of least resistance. 

Records are being frequently out of date as a result of the paper-based process.  Design drawings created using AutoCAD or Microstation are used to generate paper drawings universally used by contractors in the field. Ultimately these documents are returned as as-builts to the utility's records group who digitize hem into the utility's GIS. Utilities track their as-built backlog, the time it takes from the time an as-built is returned from the field to the time it appears in the utility GIS.  As-built backlogs run typically into months, although a year in not unheard of.

Another important source of uncertainty arises from the locates performed in response to one call or 811 information requests.  It is industry knowledge that at best ground markings are accurate to within one meter. In addition, especially with dense utility infrastructure, there is uncertainty in determining which utility has actually been identified. This uncertainty in one call locates has motivated many construction and engineering companies, who realizing that they can't rely on those markings because they are the ones that actually take on the risk and the liability, reduce risk by contracting vacuum and hydrovacuum daylighting services.   Daylighting involves safe potholing to verify the location of the utilities identified by the one call locators.  (To give a perspective of the size of this market, Badger Daylighting in Canada has over a thousand hydrovac trucks.) When the daylighters are unable to find the utility that was marked by one call locators, they will dig additional holes to try to identify the actual location of the utility facilities. As an example, for the I-70 project in Denver, which is an 11 miles of highway expansion, over 33,000 holes have been dug and that number continues to grow as the project progresses.  Daylighting is expensive, time consuming, exposes workers to risk of injury and disrupts traffic.

Mobile + cloud solution enables reliable underground location data

Mobile + cloud solutions have been developed that replaces these dated, archaic and slow paper-based workflows with near real time digital processes that result in complete, accurate and up to date records of the location of underground utility infrastructure.  Mobile + cloud solutions have been adopted by a variety of stakeholders in the construction industry including engineering firms, contractors, professional locators, and government transportation agencies.  But the value of a mobile + cloud solution is greatly enhanced when it is mandated for all construction stakeholders involved in public construction projects.

The mobile + cloud workflow is simple; capture the location data in the field with a handheld app which also collects metadata about the detection and the high accuracy GPS/GNSS devices used in the  field, upload the data to the cloud, post-process the data and in a few seconds actionable location information is available to excavators and contractors, project management and other stakeholders.

For a standard locate operation using an electromagnetic (EM) device, the EM locate tool is paired to a consumer mobile device such as a mobile phone or tablet, that's running a mobile app. In addition a precision GPS/GNSS receiver is also paired to the app to provide survey-grade, centimeter location accuracy. As the locate tool is used to identify underground utility facilities the location and metadata information is collected and pushed up to the cloud application which is running on Amazon Web Services (AWS) or another cloud processing service. Post processing using proprietary algorithms transform the raw data into actionable information and the results are available within seconds to all project stakeholders.  The metadata comprises what is referred to as the pedigree, representing all of the information that is typically recorded in a surveyors notebook.

Metadata

Metadata is a critical part of the data that is captured in real-time in the field. For example, the manufacturer and model of EM locate device, estimated depth and vertical precision, the manufacturer and model of GPS/GNSS receiver, how many satellites are in view, the original NMEA strings, date, time, XY location and estimated precision and the metadata that is used to estimate vertical and horizontal precision. Comprehensive metadata includes when the data was captures, the equipment used, who captured it, the quality level, the geographic projection and coordinate system, horizontal and vertical precision, and so on. Metadata is essential because it provides information required to assess the reliability of the data about each underground facility.

Integration with GIS and other systems

Another critical feature of a mobile + cloud solution is the ability to integrate with existing systems of record, such as a utility GIS, that are used by utility owner/operators, pipeline owner or other stakeholders. This makes it possible to stream data from the field to utility and telecom owners and operators enabling them to compare the actual locations to identify discrepancies in their records. With a click of a button they can import the data of where the utility line actually is to update their records.

Adopted by a variety of construction stakeholders

Mobile + cloud solutions have been adopted by different construction stakeholders. In Colorado Kiewit, one of the largest infrastructure construction company in North America has adopted the solution. KCI, which is one of the largest subsurface utility engineering firms in the US was an early adopter of the software and more recently T2, a major subsurface utility engineering firm based in Canada has also adopted the solution. Zayo, one of the top fiber optic companies in North America with operations in the US and Canada, is an early adopter of the software. Because the sector is extremely competitive, telecoms are extremely concerned about data protection, the ability to control who has access to fibre network data, at what location, at what time and for how long. is an essential capability for telecom operators. Blood Hound, a subsidiary of United States Infrastructure Corporation which is the largest utility locate company in North America, has adopted the software to digitally capture accurate locations of buried utilities and pipelines and then share that information with the utility owner.

Municipalities

Many municipalities have made a big investment already in a system of record, often a GIS, to geospatially manage their assets. Recently some are finding that their existing systems are slow and cumbersome and are adopting a mobile + cloud solution as a primary system of record (SOR) to manage their critical infrastructure. A key requirement is seamless integration with GISs and other systems making it possible to aggregate and present all the data that is needed in the field, by management and other stakeholders.  Furthermore in Colorado the state-wide CDOT mandate enables CDOT data to be shared with municipalities.

State-wide mandate by CDOT enhances value

While individual stakeholders have realized significant value from adopting a mobile + cloud solution (for example, one of the quantified benefits that Kiewit has realized as a result is a reduction in utility strikes on major projects by upwards of 90%, which translates into cost savings in the millions of dollars in direct costs), the value of the solution has been dramatically enhanced by Colorado DoT mandating a single mobile + cloud solution for the entire state.  Everyone who owns, operates, maintains or installs utility or pipeline equipment in the state right of way by law is required to use the same software software which enables contractors, locators, subsurface utility engineering firms, utilities and telecoms, and government transportation authorities to share their data. CDOT has acquired a number of mobile licences that enables it to provide handheld apps to all its construction contractors so they are able to view CDOT data in the field and also add to the data as new infrastructure is installed or existing infrastructure is relocated in preparation for a road or highway project.  Furthermore CDOT now requires that over 150 utility companies and more than 1,000 utility installation stakeholders use the same solution to capture and record the location of underground utilities.

The provisions of the Colorado Revised Statutes has resulted in the reliability of the data contained in the CDOT database being much higher than is typically found in utility or telecom records. The high accuracy underground utility data comes from two sources, both mandated by the recent Colorado Revised Statutes; subsurface utility engineering surveys (SUE) and as-builts submitted for newly installed utility and telecom infrastructure. In addition, in some parts of Colorado, for example, the western slope, CDOT is inventorying existing underground infrastructure in the public right of way to support future civil engineering projects. Ultimately it is to be expected that the CDOT data will comprise a complete, up to date, high accuracy map of underground assets in the public right of way in Colorado. Such a map will provide immeasurable benefits to everyone involved in construction in the public right of way.

This post is based on Page Tucker's keynote at the Canadian Underground Forum (CUF). You can listen to all the talks at CUF on the GeoIgnite CUF Youtube channel.

Democratizing reality capture for underground pipeline and utility infrastructure

A revolution is happening in how we map new underground infrastructure. Instead of the paper as-builts submitted after the completion of construction for a new pipeline or other infrastructure, network owners may now request a LiDAR scan of the newly installed equipment before the trench is filled.  There are several reasons for this.  First and foremost is that LIDAR scanning has become so easy and fast that it is literally accessible to everyone. Secondly, a LIDAR scan not only captures the survey-grade location in 3D of new infrastructure, but a lot more information besides.  Thirdly, LIDAR scanning has become so inexpensive that it does not really add to construction costs. With the democratization of modern reality capture technology the availability of comprehensive, high accuracy 3D location data about underground pipelines, utilities and other infrastructure is growing.

When Leica Geosystems released the BLK360 laser scanner, this was revolutionary for several reasons;  it was small,   it only had one button, its price was unheard of in the world of professional laser scanners, and the result of a scan could be seen a few minutes later on an iPAD. This device was all about democratizing reality capture. The BLK360 was Leica's play to make professional-quality reality capture available to anyone who wants it.

Utilities have used LiDAR and photogrammetry for a number of applications involving above ground infrastructure, for example, for vegetation management and to reduce safety issues and costs when conducting a high accuracy inventory of above ground infrastructure.  But this changed in 2018 when Lux Modus entered the pipeline mapping market with the objective to change field mapping fundamentally by making the capture of high accuracy maps of underground infrastructure accessible to anyone and at a low cost. Consisting of high-density digital LiDAR, three 13 megapixel cameras, with GNSS with base station correction the Lux Modus device only requires one touch to initiate scanning which frees the user from having to manage the system while driving around the collection area.The device can be mounted on a rig on a pickup truck and by simply driving the truck along the line prior to filling the trench captures survey-grade location information and a lot more information such as depth of cover, location of weld points, and nearby utilities. The point cloud and images are uploaded for cloud processing and within a few minutes a 3D image of the new section of pipeline can be viewed by anyone with a browser that supports HTML5 including mobile devices. 

There are two use cases where LiDAR scanning can be applied two underground infrastructure. The first is when new utility infrastructure is installed and before the trench is covered.  Some jurisdictions are already mandating survey-grade accurate as-builts for new installations.  The second case is when existing infrastructure is exposed for repair or relocation.

The underground mapping industry has been facing two historical challenges.  The first is that when new network infrastructure is installed by a contractor, the so-called as-builts that are submitted to the utility after completion of construction rarely reflect the actual location of what went in the ground. The problem is that calling a survey crew and then redlining the original design to indicate where equipment was actually installed is expensive in time and cost. Furthermore, contractors are remunerated based on how rapidly they can get new equipment in the ground, not on the accuracy of the as-builts they submit.

The second problem is the result of the first. Most of the existing location data for underground utilities contained in utility and telecom network records is inaccurate, out of date or just missing. In responding to one call locate requests, utility locators have to rely on these same utility records augmented with remote detection techniques to try to detect and identify their network equipment. Contractor often have to  conduct daylighting operations using vacuum or hydraulic excavation equipment to verify what utility locators believe they have have identified and painted on the ground. Line locating and daylighting requires special equipment, software and training to do things efficiently. But even with experience detecting and identifying underground network facilities remains a slow, error prone process that can expose workers to the hazards of traffic and other safety risks and can play havoc with construction schedules.

A number of jurisdictions, realizing that the capture of point clouds is accessible and low cost, are dispensing with traditional paper as-builts and requesting LiDAR scans instead.  As a result of Lux Modus this is happening in the pipeline industry in Western Canada. Lux Modus started mapping pipelines because that was the hardest use case they could find. Now Lux Modus is expanding into other sectors such as rail, power transmission, and urban mapping first in Canada and the United States and soon in Europe. Recently in Denmark two water utilities in the Greater Copenhagen and Aarhus areas are efficiently generating point clouds of underground utility infrastructure using a handheld phone and accurately surveyed control points.  These point clouds are captured for both newly installed infrastructure and for infrastructure exposed during repairs of existing infrastructure.  Novafos, a water company in the Greater Copenhagen area, already has thousands of these point clouds which capture not only high accuracy location of the water utility's underground infrastructure, but a lot more information including the location of nearby utilities which would be a concern for any excavation involving the water lines. 

This post is based on Joseph Hlady's keynote at the Canadian Underground Forum (CUF). You can listen to all the talks at CUF on the GeoIgnite CUF Youtube channel.