Last week I was invited to speak at the Alberta Land Surveyors Association Annual General Meeting in Banff, Alberta about locating and mapping underground infrastructure. I thought it would be worthwhile to share the talk that I gave where I highlighted opportunities for surveyors.
The subsurface is often ignored. This is partly a case of out-of-sight is out-of-mind. But it is also the result of broken business processes in the construction industry that place much greater value on physical assets than on what is now being called the digital twin representing the location, behaviour and status of underground assets. Knowing the location of underground energy infrastructure is critical for national security, for disaster planning and management, for public safety and for economic efficiency. Everyone is aware of at least one disaster resulting from or exacerbated by not knowing where our energy infrastructure is - the recent explosions in San Francisco and Durham NC and the evacuation just last week of a neighbourhood in Calgary when a 6" gas line was hit during an excavation come to mind.
Impact of unknown and inaccurately located subsurface infrastructure and geotechnics
The best documented example I know of the economic impact of not knowing accurately where underground infrastructure is the Sydney Light Rail Extension Project. This is a $2.1 billion PPP project for 12 km of light rail to be completed by 2019. Prior to awarding the contract for construction the Department of Transport for New South Wales undertook 12 months of work to map 5,000 subsurface utilities along the route. 500 existing subsurface utilities were identified for relocation to make way for the new light rail infrastructure. During construction it was found that the as-built information from utility providers was frequently unreliable including incorrect location and incorrect materials. The second problem was that during construction an additional 400 unknown services were encountered. As anyone in the construction industry will tell you - discovering unknown underground utility infrastructure occurs frequently on construction projects. Both of these caused disruption and delays with construction. In this case ACIL Allen, a respected Australian consulting firm, was asked to estimate what the impact of unknown and inaccurately located utilities was on the project. Their study concluded that if a complete and reliable 3D map of underground infrastructure had been available at the project planning stage, the project could have been completed at least one and a half years sooner, at less cost with a much lower level of risk. While the project apparently remained ‘on time and on budget’, ACIL Allen says that this is only because the risk of delays and additional costs resulting from unidentified underground utilities were included in the contract pricing and schedule.
An example that shows the benefit of knowing where underground utility infrastructure is located is the I-20/I-59 Corridor project in Alabama. This is a $750 million interchange project in the heart of Birmingham's business district. For this project the Alabama Department of Transportation (ALDOT) took an unusual approach. Using potholing, scanning with ground penetrating radar, professional surveyors and existing as-built records a 3D model of below-ground utilities was created. When the project was put out to tender each contract each bidder was provided with the 3D model. ALDOT estimated that it saved $10 million on the project with this approach. Perhaps more importantly the project remains on schedule and on budget - remarkable for a project of this complexity and magnitude in a dense urban environment.
Setting the context: the construction industry is ripe for digitalization
To put this in context there is massive investment in infrastructure projects around the world as evidenced by the US$ 90 billion Delhi-Mumbai industrial corridor project in India which will affect some 180 million people. McKinsey estimates that we will need to spend $57 trillion on infrastructure over the next decade or so. But how infrastructure is financed is changing and this is changing the construction industry. Governments have less and less money for capital projects. Since 2003 growing amounts of private capital have been going into infrastructure projects. In 2016 total private investment in infrastructure projects reached nearly $80 billion. Unlike government which looks for a social return, private investors such as pension funds, insurance companies, and sovereign wealth funds require a financial return. This drives a focus on improving productivity. As the automobile manufacturing, financial services, airline and other industries have shown this drives investment in IT technology.
McKinsey has made the case that construction is ripe for transformation and that digitalization will be a key technological driver. R&D investment in the construction industry has been among the lowest of any industry, ranking nearly last, at the same level as hunting. Construction productivity in the world's advanced economies including Germany, Japan, UK, EU, US, and South Korea has been stagnant or declining for the past 40 years, a period during which general industrial productivity has more than doubled. McKinsey has made the case that digitalization could help raise construction productivity and identified five technologies that it believes will be key for transforming the construction industry. Two of these are building information modeling (BIM) and geospatial.
BIM+geospatial provides the basic technology for modelling underground infrastructure. BIM involves a 3D model, associated data, and a collaborative approach to construction. BIM has been or is being mandated for public works in many countries and has also been adopted by many private sector companies. Furthermore there is growing evidence of the benefits of an integrated BIM + geospatial full lifecycle approach to construction, especially for infrastructure projects. For example, it has been estimated that applying this approach for the Nagpur Metro project will save over $200 million over the 25 year lifetime of the project. In Canada EllisDon, who began taking on PPP projects 15 years ago, has made integrated BIM+geospatial a best practice for their PPP projects.
To drive improved financial returns and attract private capital owners and the construction industry are looking for low hanging fruit. Reducing the risk of unknown and inaccurately mapped underground utilities can dramatically reduce costs and duration for construction projects as the Alabama I-20/I-59 Corridor project has shown.
Key facts about unreliable and incomplete information about subsurface infrastructure
The Common Ground Alliance (CGA) collects statistics regarding damage to underground infrastructure during construction. The CGA estimates that there are 400,000 cases of utilities being hit during excavation every year at at average cost of $4000 in direct costs per hit. In the U.S. according to Federal Highway Administration (FHWA) underground utility conflicts and relocations are a major cause of project delays during road construction. In addition every year there are injuries and deaths attributable to hitting underground utilities.
In the U.K. research by the University if Birmingham has estimated that the direct cost of a utility strike during construction ranges from £ 300 for water and sewer to £ 2,800 for fiber-optic cables. More importantly the indirect and social cost, which includes traffic disruption, injuries to workers and the public, and loss of business custom was estimated to be about 30X the direct cost.
Every construction project requires investing time and effort prior to and during excavation to locate underground utilities. Construction bids are routinely inflated by 10-30% to accommodate risk associated with unknown or poorly located underground utilities In the U.S. this has engendered what is estimated to be a $10 billion per year industry. Every state in the U.S. and most provinces in Canada have a one-call centre and legislation that requires anyone planning to excavate to contact the centre. Utilities and telecoms are required to send crews to locate and indicate with paint or pin flags the location of their underground infrastructure. Because they are considered liable for any underground damage, wise construction contractors do not rely solely on this information but increasingly use expensive vacuum and hydro excavation equipment in detecting and exposing underground infrastructure during excavation. But the information captured by these techniques is rarely shared and the location of underground infrastructure is recaptured over and over again.
Together this represents a considerable drag on the construction industry. In the U.S. if indirect and social costs are included this represents at least a $50 billion drag on the economy and this does not include insurance costs. Of this the largest share is borne by the consuming public in the form of service disruption - phone, power, heating and water outages.
Several university studies have estimated the benefit in terms of an ROI of knowing accurately where underground infrastructure is located. One of the most recent by Pennsylvania State University found $21 in cost saving for every dollar invested in improved location information about underground infrastructure. In the U.S. the Federal Highway Authority (FHWA) cites studies that have shown that the cost of detecting underground utilities prior to construction typically costs less than 0.5 percent of the total project construction cost, saves more than $4 for every $1 spent, and can reduce project delivery time by as much as 20 percent. A study resulting from an underground survey in Milan in preparation for a World Fair there estimated that €16 were saved for every € invested in accurately locating underground infrastructure.
Underground utilities and highway construction
The Alabama I-20/I-59 Corridor project has shown that a 3D map of underground infrastructure can reduce risk and keep highway construction projects on budget and on schedule. As Ron Singh, who was Chief of Surveys at the Oregon DoT, has argued, underground utilities are a huge problem for highway construction projects. In his view we need to stand the traditional highway construction process on its head. He explained that this means the traditional approach - survey, design, locate utilities, move utilities, build, and prepare as-builts - needs to be replaced by an approach that relies on a prior 3D model of above and below-ground infrastructure which will provide 85% of the information required about the existing site and situation. The new process will require a rapid initial survey for sanity checking the information in the 3D model followed by design with knowledge of underground utilities. This approach would avoid expensive moving of utilities as much as possible and only move utilities that cannot be avoided during design. During construction underground utilities would be laser-scanned. A post-project 3D survey and laser-scanning would replace paper as-builts. A side-benefit of this approach is that it would with time build up accurate models of highways which many believe will be essential for the safe operation of autonomous vehicles.
Cost-effectively mapping the underground
The keys to cost-effectively and accurately mapping underground infrastructure are first of all policies and technologies that ensure that the location of new infrastructure going into the ground is captured accurately and cost-effectively, secondly policies and technologies that require that the location of infrastructure exposed during construction is captures accurately and cost-effectively, and thirdly policies for sharing information about underground infrastructure (essential in the U.S. where this information is restricted under Critical Infrastructure Protection (CIP) regulations). These goals will require modernized quality standards for underground infrastructure, standards for sharing underground infrastructure location data, and hardware and software advances for cost-effectively and accurately detecting and recording the location of existing underground infrastructure. There are important opportunities for professional surveyors in capturing accurately and responsibly the location of new and existing infrastructure. The challenge will be to develop new business practices and adopt new technologies to be able to do this cost-effectively so as not to significantly increase the cost of construction or burden government with major additional mapping costs.
Technology advances in detecting underground infrastructure
A research project by Costain and Bentley investigated using photogrammetry with photos taken by consumer grade smartphones together with professionally surveyed control points. Typically it involves taking 40-60 pictures of exposed infrastructure with a smartphone. This process has been found to result in a 3D model of comparable accuracy to a traditional survey, is much more cost-efficient and once the control points are surveyed is something that anybody can do. Most importantly it enables the capture of accurate underground utility location during construction with little additional cost.
In a similar vein Bentley Systems has experimented with a system that equips excavation equipment with four inexpensive digital cameras that are used to collect images of underground infrastructure encountered during excavation. 
The resulting videos and images were then loaded into Bentley ContextCapture software and exposed pipes and cables located with centimeter accuracy by referencing accurately surveyed neighbouring structures such as houses and other buildings. Again this approach enables the capture of accurate location data about underground infrastructure location during construction with little added cost.
In 2018 two technical advancements in detection were reported that bring the cost-effective mapping of underground infrastructure at the municipal, regional, and national level closer to reality. T2 Utility Engineers, based in Whitby, Ontario commercially use a IDS GeoRadar Stream EM multi-channel ground penetrating radar (GPR) array towed routinely at 10-12 km/hr to capture subsurface data. 
In a separate initiative a successful proof of concept has been reported by DGT Associates in Mississauga, Ontario in which data collected by a Siteco rig combining a Faro mobile laser scanner and Sensors and Software GPR arrays collected data simultaneously above and below ground at roadway speeds of 80 to 90 km/hr. In both cases the data was collected in soil conditions that were less than optimum for GPR. Being able to capture data at or near roadway speeds addresses an important obstacle to efficiently creating 3D maps of the underground. In both cases significant time was required to post-process the collected sc 
3D models. However, advances in software are making this process more reliable and faster.
In another interesting development Lux Modus has developed a rig and software running in the cloud that captures 3D location information in "near real-time" as a pipeline is constructed. The rig includes LiDAR and photo cameras which capture the trench and the pipeline by driving along each section before the trench is filled to record a point cloud and photos. The point cloud and images are uploaded for cloud processing and within minutes to hours a digital twin of the pipeline can be viewed by anyone with a browser that supports HTML5 including mobile devices. For example, this makes it possible for QA/QC people to use mixed reality to identify weld points in the office rather than having to go out in the field.
Satellite sensors are also finding application in detecting damage to underground infrastructure. Planetek has developed an application Network Alert that uses Sentinel-1's radar interferometry to monitor ground subsidence with millimeter precision. Network Alert alerts water utilities af areas of subsidence which can be symptoms of water leaks.
There are further indications of accelerating research and development initiatives related to underground infrastructure. In the U.S. for the first time the Common Ground Alliance (CGA), which represents the utility locate industry in North America, has just released a Technology Report, which describes the current state of underground detection technology including the latest developments and the gaps which CGA has identified in current hardware and software.
In the UK there have been quite a few research initiatives relating to underground infrastructure. The Mayor of London and the Smart London Infrastructure Network, which is composed of utilities responsible for water, energy, telecommunications and waste management in London, sponsored a challenge with the objective of developing digital technologies to accurately locate underground assets, including pipes, cables and joints, and determine their condition. The goal was to improve safety, and to reduce operational downtime, cost and environmental impact, and disruption. A national 10 year academic research program Mapping the Underworld focussed on remote-sensing for locating sub-surface utilities is completed and been replaced by a follow-on 10 year program Assessing the Underworld. The BIM for the Subsurface (2015-2017) project, funded by Innovate UK, aimed to address issues such as project delays due to unforeseen ground conditions by applying the BIM process directly to ground investigation and subsurface infrastructure design.
Sharing information about the underground
To complement the advances in detection there are several initiatives to develop ways to share information about underground infrastructure that is captured during construction. The City of Chicago has launched a pilot to deploy a platform for collecting data and creating and sharing a 3D map of underground. It is based on new technology developed by University of Illinois at Urbana-Champaign’s Real-Time and Automated Monitoring and Control Lab (RAAMAC) and Chicago start-up CityZenith. During excavation a dozen or more pictures are captured with an inexpensive digital camera. RAAMAC's software uses the photos to create a 3D digital model of the underground infrastructure. These models can be securely shared between the City of Chicago and construction contractors to improve project planning and limiting accidents. The advantage of this approach to data collection is that it does not interfere with construction and does not add any significant cost.
But perhaps the initiative that everyone interested in improving knowledge of the underground should be following is a national program in the Netherlands which is supported by legislation and standards. In 2015 a new law was passed by the States General which created the Basisregistratie Ondergrond (BRO) or Key Registry for the Subsurface. This database is open and accessible to all citizens of the Netherlands. This went live in 2018 and requires that if you excavate or drill you have to share your data relating to geotechnics with the BRO registry. In addition if when using the data in the registry you find something is incorrect you are required to report it.
While the BRO registry in the Netherlands relates to subsurface geotechnics, the Geopatial Commission in the Cabinet Office in the U.K. government has just announced an initiative to create a registry of underground infrastructure assets. The register will show where electricity and telecom cables, and gas and water pipes are buried and is intended to prevent both accidents and disruption to the economy. The project will start with £3.9 million pilot projects split between London and the North East.
Worldwide initiatives to map underground infrastructure
There are successful examples around the world where municipal and regional governments have helped enable a shared underground utility network database. I have blogged about a few shared databases of utility location data (water, sanitary and storm sewers, electric power, telecommunications, gas, and district heating) I've encountered worldwide over the years: Sunderland UK, Netherlands, France, Chicago, Alabama, Singapore, Sydney, Milan, the KLIC system in the Netherlands, KLIP in Belgium, Penang, Sarajevo, Calgary, Edmonton, Jalisco, UK, Japan, Bahrain, Rio de Janeiro and Sao Paulo, Delhi, Bern, and even an open water network portal in New Zealand. Perhaps the closest to a shared integrated infrastructure database is the one supported by the Integrated Cadastral Information Society (ICIS) in British Columbia which includes geospatial data for property boundaries, utility and communications networks, taxation jurisdictions, conservation districts, and the agricultural land reserve. Most of the shared infrastructure information initiatives I have come across involve government, some result from regulation, others are run by government, still others involve cooperation between government and participating utilities and communications firms, and a few are voluntary industry consortia.
The grandfather of shared underground infrastructure databases is the system developed many years ago for Tokyo. The mainframe-based Road Administration Information Center (ROADIC) system, which was deployed first in Tokyo and then in other major cities in Japan, provides information about the location of underground infrastructure including telecommunications and utilities.
In North America the City of Calgary, Alberta mandated the JUMP (Joint Utility Mapping Project) many years ago. A city by-law requires that anyone placing cables or pipes undergound within city limits provide 2D maps in electronic form showing the location of the infrastructure. Originally in the form of DGN files the maps only show location and type of infrastructure (water, gas, electric power, telecom) and owner. The City of Edmonton, Alberta also has a shared facilities mapping database.
Las Vegas has conducted a pilot for a 1.5 mile corridor of Main Street in old Las Vegas. Using a variety of reality capture technologies including GIS, survey, design records, test holes, and ground penetrating radar (GPR) a 3D model of above below-ground infrastructure was prepared. Las Vegas also attempted to ensure that in the future accurate 3D location of new or displaced infrastructure would be captured. Contractors were required to use open trenching, to survey new and displaced utilities before closing trenches, and to avoid trenchless digging if possible. Augmented reality was used to visualize above and below-ground infrastructure.
In France a national regulation requiring mapping of subsurface infrastructure titled Decree relating to excavations near underground, overhead or underwater transmission or distribution networks was promulgated on 15 February 2012. It requires mapping all critical underground infrastructure in urban areas by 2019 and in rural areas by 2026. Across France different departmental organizations have taken responsibility for implementing the decree.
The Urban Redevelopment Authority (URA) of Singapore intends to release a masterplan of Singapore's subsurface infrastructure in 2019. It will be released as part of the next national Master Plan for Singapore's development in the medium term. When completed it will provide the first comprehensive 3D map at what lies beneath the surface from utilities a few meters deep to transportation tunnels, deep sewer lines, deep petrochemical storage, deep water reservoirs and even deep ammunition stores.
The North East Underground Infrastructure Hub (NEUIH) is the overall initiative name for an initiative supported by the Ordnance Survey and Northumbrian Water to map underground infrastructure in the North East of England. The first phase of this project was a ‘Common Infrastructure Map’ covering a few small sample areas around Newcastle. This combined map is the first step towards creating the NEUIH. The current phase of the OS initiative is called ‘Sunderland sand box’ and implements a dataset that contains almost full water, gas, electricity and a great deal of telco data for the city of Sunderland.
Standards for underground infrastructure
Recently there have been developments that reflect improvements in underground remote sensing technology. Standards for reporting the reliability of the locational information about underground utilities have been in place for decades. In the U.S. the 2003 ASCE 38-02 which has been used for classifying location information about underground infrastructure according to its estimated reliability, is widely seen as being out of date. In Canada the CSA S250 standard released in 2011 specifies absolute precision levels for exposed utilities. In France the 2012 presidential decree defines three explicit levels of cartographic accuracy for underground structures; A - less than 40 centimeters, B - 40 centimeters to 1.5 meters, and C - greater than 1.5 meters. In the UK the 2014 Publicly Available Specification PAS128, developed under the auspices of the British Standards Institution (BSI) and sponsored by the Institution of Civil Engineers (ICE) and others, not only includes the A,B, C, D quality levels of the U.S. standard, but extends it with explicit precision levels B1 to B4 that reflect the improved capabilities of underground remote sensing technologies such as electromagnetic induction and ground penetrating radar. A process to revise PAS128 to reflect newer technical developments has just been initiated.
For sharing information about underground infrastructure the Open Geospatial Consortium's (OGC) underground information initiative, with the appropriate acronym MUDDI, is intended to provide an open standards-based way to share information about the below ground. The MUDDI project has identified several different broad use cases that the model is intended to support including routine street excavations (EX), emergency response (ER), utility maintenance programs (OM), large scale construction projects (AE), disaster planning and response (DP), and smart cities programs (SC). For each of these, several basic requirements that the model needs to satisfy have been identified. For street excavations the requirement is location of all entities with high horizontal, medium vertical accuracy (2.5D) of underground infrastructure; for large construction projects, detailed 3D geometry of underground infrastructure and detailed 3D geology; for emergency response, interdependencies between different networks; for utility maintenance, network topology and facility location and condition; and for smart cities the ability to monitor and relate streams of data from sensors.
The MUDDI model is intended to build on and be compatible with many existing reference/target models. For infrastructure these include CityGML with Utility Network ADE (Application Domain Extension) , INSPIRE Utility Networks, IMKL (Information model for cable and pipes), BIM-IFC, Land and Infrastructure Conceptual Model (LandInfra), Singapore Underground Geospatial Model, PipelineML, Underground Pipeline Information Management System, CIM (Common Information Model), Multispeak, ESRI Utility Model, and GEOfeature. For geotechnics, the reference/target models are GeoSciML, INSPIRE Geology, GroundwaterML, BGS National Geological Model, EarthResourceML, GeoTOP, SoilEML, IFC Geotechnical Extension, MINnD, and BoreholeIE.
To provide a way for the model to be used by different types of users, the concept of profiles has been introduced. Profiles have been used for other OGC standards and allow for different levels of complexity for different domains and applications. The proposed profiles include asset, excavation, emergency, planning and integration profiles.
National initiatives to map underground infrastructure
In the UK combining above and below-ground information into one national digital twin will allow industry to share business developments and innovation activities. Project Iceberg is an exploratory project undertaken by the British Geological Survey, Ordnance Survey and the Future Cities Catapult to investigate ways to integrate data and services relating to the underground with other city data. To date two reports Market Research into the Current State of Play and Global Case Studies and Defining the problem space for an integrated data operating system above and below ground have been published and are publicly available.The medium term objective is to take these concepts forward with project partners to develop new digital data demonstrator projects.
In the U.S. to begin to address the challenge of accurately mapping national critical infrastructure the National Academy of Public Administration (NAPA), Arizona State University (ASU), the American Geographical Society (AGS), and the National Academy of Construction (NAC) convened leaders in public administration, infrastructure development, geography, geospatial, and data integration/open data at Arizona State University in Tempe, Arizona.
At Geospatial World Forum 2019 I learned of an initiative in Estonia, one of the most digitalized countries in the world to create a national digital twin of above and below-ground infrastructure.
Wrap-up
In summary unreliable information about the location of underground infrastructure and underground geotechnics costs world economies billions of dollars every year. Missing or inaccurate information adds risk to every construction project. In the U.S. locating subsurface infrastructure is a $10 billion per year industry. The information is rarely shared with the result that this information is recaptured over and over again. To provide a standard for sharing information about the underground including infrastructure and geotechnics the Open Geospatial Consortium has initiated a standards development effort called MUDDI which is being built on many existing standards. An important national initiative to share information about the underground has begun in the Netherlands. The UK government has just initiated the process to create a national registry of underground assets in the U.K.
A number of cities and regions around the world which have already recognized the importance of reliable information about the underground have developed ways of collecting and sharing information about the subsurface. Recently the awareness about the importance of information about the subsurface has reached the national level. France has mandated that the location of critical underground infrastructure must be known to within 40 cm. Recent initiatives in Estonia, Singapore, the U.K. and the U.S. are aimed at creating national digital twins including underground infrastructure.
Professional surveyors could have an important role in capturing accurately the location of new and existing infrastructure. The challenge will be to develop new business practices and adopt new technologies to enable this to be achieved cost-effectively – in the short term it cannot increase the cost of construction or burden government with significant additional mapping costs. In the long term the benefits include reduced risk for construction contractors which will reduce costs especially insurance. It will also provide significant benefits to owners including government by reducing the cost of infrastructure construction and maintenance.
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