Between the Poles

ASCE standards reduce risk and expedite public highway construction projects

What the engineer does during planning and design has a multitude of impacts: traffic disruptions to the public, safety for workers on construction sites, avoiding delays and budget overruns on projects, decreasing risk to contractors, and reducing cost to the rate paying public. It really is a matter of public welfare and that's why the ASCE 38 and 75 standards are engineering standards. What we'd like to do is enter into a world where we we have as reliable information about the subsurface as we do about the above ground and the location of underground infrastructure is well understood in the design stages.  Then we can start applying modern 3D BIM design technologies, virtual design, and new other technologies to enable the construction process to proceed as rapidly as possible with the least amount of risk and rework. And that's going to save everyone money and a lot of headaches.

Regulating the public ROW

With respect to underground utilities the key idea is to avoid, accommodate and then relocate. This will require changing the mindset of agencies such as DOTs that should be regulating work in the public right of way. Currently many DOTs allow the utility operators free rein to build and operate in the ROW. They take a hands off approach saying it is not their responsibility, it's the utilities operators/owners problem. At this point it is generally recognized that this approach no longer works because everybody is accountable when things go wrong and a gas main gets broken and a building explodes. If we can accurately locate, map and accommodate underground infrastructure during planning and design, just as we do using above ground surveys, we expedite the project by taking the risk arising from underground utilities out of the critical path. By speeding up these jobs you can really save a lot of money on major construction projects.

ASCE 38-22 for SUE Surveys

In contrast to the 38-02, the latest version of the 38-22 standard for SUE investigations is both prescriptive and a performance standard. It is prescriptive in that it specifies the minimum actions that must be undertaken to achieve (or attempt to achieve) a particular quality level. As a performance standard it describes the professional judgment that needs to be exercised to determine the appropriate timing, sequencing, location and scope of a utility investigative effort to achieve the goal of reducing utility issues during planning and design by achieving Quality Level B or A for all underground utilities. ASCE 38-22, unlike 38-02, specifies levels of positional accuracy. 

We wanted to provide better definitions so that there's greater clarity in what constitutes a SUE survey.  The SUE survey must be stamped by a professional engineer and In addition be accompanied by an engineering report that goes with the submittals to help lay out what has been found, where issues and discrepancies were encountered, and the things you need to be especially careful about. It includes our recommendations going forward on the project, what you need to consider and  where you may need to do more advanced geophysical investigations or vacuum excavations to better define the design, where you need coordinate closely with utility owners, how to prepare construction documents and plan construction. The liabilities behind this document is significant. To protect the owner, the contractor, and the engineer whoever has provided the SUE data and service must be able to document what they did sufficiently to be able to stand up in a court of law and say, "We met the standard of care."

ASCE 75-22 As-installed

We define the spatial and the attribution properties of the facilities that we want to record, so that at the end of the day, we can actually create a digital twin in a user friendly format and consistent format. We have defined minimum, optional and conditional attributes and the minimum requirements, list the information we must have to create a digital twin or very useful 3D model of our infrastructure in a standardized manner.

In Montana we have a permitting system for work in the public ROW and we can collect these attributes and an approximate alignment at the time of applying for the permit. The person filling out the permit application understands the required attributes and can plug them right in. And then when the actual work is performed, the approximate alignment's upgraded to the actual observation via the survey data. ASCE 75 has been implemented in Montana for several years now and has won both Montana and national engineering awards.

We also support absolute spatial positioning and have have a framework for data exchange by having a standard datum. At the National Oceanic Atmospheric Administration (NOAA), this is the same thing we do for nautical charts and hazards to navigation. We're just applying it to hazards to excavation. Everything is referenced to the National Spatial Referencing System. That gets rid of all the distortion that happens when you're trying to take something on a sphere and flatten it on a flat plane. You get distortions, there's different projections, state plane, county coordinates, UTM and they all distort the image. By having everything referenced to the National Spatial Referencing System, when you bring it together, it's going to go in the same spot every time. And it accounts even for plate tectonics and crustal drift ln places like California, Whenever you're turned on your GNSS system, you're tied into the National Spatial Reference System. It is being upgraded and the next version should come out in another year.

ASCE 75 specifies levels of positional accuracy. There's an accuracy table that goes with the standard, which we basically piggybacked off CSA S-250, the Canadian standard. We have CSA S-250 people on  our 75 standards committee. They also told us three things that they wish they had included with CSA S-250; make it a digital standard, secondly make it 3D and thirdly include above ground infrastructure with the standard. So we made sure we brought those into ASCE 75-22.

The Open Geospatial Consortium (OGC) has adopted both ASCE 38 and 75 as important input to their Model for Underground Data Definition Initiative (MUDDI ). The MUDDI model provides a base conceptual data model for interoperability and data exchange.  It is being adopted world wide including by the NUAR initiative in the UK, the UNUM project in New ,and other jurisdictions.

Securing sensitive information

Data stewardship includes issues of sensitive and secure information.  Here in the U.S, we're using 49 CFR Part 1520, which talks about how to manage sensitive secure information that TSA has determined to be Sensitive Security Information, as defined in § 1520.5. (This part does not apply to the maintenance, safeguarding, or disclosure of classified national security information.) It's a big issue with many utility owners. They don't want that information available to everyone. The 49 CFR Part 1520 guidance defines what information needs to be kept secure and that has helped alleviate the data protection concerns of the utility owners.

Conclusion

With the imminent availability of the ASCE 38-22 and 75-22 standards, every underground utility segment that's depicted can be assigned Quality Levels based on ASCE 38-22 for existing infrastructure or from the ASCE 75-22 "As-installed" standard for newly installed infrastructure. For example, in Colorado both draft standards are mandated for all work in the public ROW. This enables a world where we we have as reliable information about the subsurface as we do about the above ground and the location of underground infrastructure is well understood in the design stages. Then we can start applying modern design technologies to produce better designs which enable the construction process to proceed as rapidly as possible with the least amount of risk and rework.

This post is based on Phil Meis' (UMS and ASCE) talk at the Subsurface Utility Mapping Strategy Forum (SUMSF).

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

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

Underground infrastructure mapping in NYC

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

9/11 emergency

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

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

Unification for Underground Resilience Measures (UNUM)

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

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

Use cases addressed by UNUM

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

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

Quality and availability of subsurface infrastructure data in NYC

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

Single integrated map

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

An open standards-based model for underground infrastructure

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

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

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

Conclusion

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

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

Visualizing underground infrastructure for multiple utilities on a single map

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

Background to NUAR

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

Integrating underground data from different utilities

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

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

Developing a harmonized data model

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

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

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

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

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

Progress of NUAR build phase

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

 

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

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.

CSA S-250 one of the first national "as-installed" standards for underground infrastructure

In Canada the goal of the Canadian Standards Association (CSA) S250 Standard, first published in 2011 and revised in 2020, is to specify mapping requirements for the recording and depiction of newly installed underground utility infrastructure and related structures. It is intended to promote communication and data sharing throughout the construction lifecycle of projects and asset life.  Specifically it is intended to improve the reliability and accuracy of underground utility infrastructure mapping records and supporting data.  Accurate records provide greater safety to the public and construction workers by decreasing utility infrastructure line hits and strikes and by augmenting and enhancing damage prevention programs, such as state and provincial one call programs and initiatives by contractors, utility owners/operators and state and provincial transportation agencies. CSA S-250 has been adopted by agencies such as the Ministry of Transportation of Ontario and the Ontario transit authority Metrolinx and utility owners such as Enbridge. The best practices guide developed by the Transportation Association of Canada (TAC) recommends that "as-builts" submitted for newly installed and relocated infrastructure be compliant with CSA S-250.

The CSA S-250 standard is a precursor to and has much in common with the new U.S. "as-installed" standard ASCE 75-22 developed by the Utility Engineering and Survey Institute (UESI) and already in use in Colorado and Montana.  In particular the horizontal and vertical positional accuracy levels adopted by ASCE 75 are shared with S-250 and while not identical are very close.

CSA S-250

The CSA S-250 standard specifies 3D mapping requirements for the recording and depiction of underground utility infrastructure and related attributes at or below grade. Unlike the ASCE 75 standard it does not apply to above grade infrastructure such as poles and overhead wires.  It was one of the first standard to specify levels of positional accuracy - for both horizontal and vertical dimensions. Throughout the standard "shall", "should", and "may" are used consistently to distinguish mandatory, recommended, and optional requirements.

What's new in CSA S250:20 ?

New field locating and mapping technologies are being developed and existing technologies evolving.  The latest version of the standard has expanded the recognized technologies to include LiDAR, total station survey (TSS) and video recording for supplemental records.  The requirements for mapping records has been expanded to include all stages of operational status; proposed, existing, abandoned in place, retired, or reserved for future use. The challenge of digital base mapping is explicitly discussed, because in North America in general every utility has adopted a different base map. Clarification is provided on how information is to be collected and used to depict the location and attributes of utility infrastructure so users can be confident of its level of reliability and accuracy. The owners' responsibility for measuring and recording the location of underground utility infrastructure has been revised.  The requirements for absolute spatial positioning (i.e., horizontal and vertical datums) have also been revised. The importance of open data standards, for example the Open Geospatial Consortium's MUDDI standard, that enable data sharing between industry partners has been explicitly recognized.

The revised standard specifies that field records and data "shall" be collected contemporaneously during construction. The owner "shall" define the type and format of the field records collected.  Field records "should" be the primary source of mapping information.  Furthermore, anyone who discovers what appears to be a significant discrepancy during construction, excavation, SUE activities, and locating "should" report the discrepancy to the owner and/or source of the record in a timely manner.

Example of petroleum/gas distribution system

As a concrete example of the level of detail that is provided by the standard, for a liquid petroleum or gas pipe distribution system, the standard specifies a minimum set of properties that "shall" be captured and others that "should" be captured.

Mandatory
horizontal and vertical position and accuracy levels
cross-sectional size of pipe
material type of pipe
material of casings
pipeline coating
cathodic protection

Recommended
Valves, tees, fittings and plugs
Compressor stations, pressure reducing stations
Pipeline maximum operating pressure

Symbolization

A solid line "should" be used to depict existing infrastructure, an "x" though the solid line "should" be used to depict abandoned facilities, hatching "may" be used to depict proposed infrastructure.

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

New digital "as-installed" standard for underground and above-ground utility infrastructure

Since 2002 there has been a standard, ASCE 38, for investigating and documenting existing underground utility infrastructure.  Now in the US a new standard ASCE 75 is imminent that will define a standard way to record and exchange information about newly installed infrastructure. This means that in the future all underground infrastructure can be assigned a quality level, either under ASCE 38 or ASCE 75.

Developed by the ASCE Construction Institute (CI) and Utility Engineering and Survey Institute (UESI) the new "as-installed" standard is currently available for public comment through January 6, 2022. It has already been adopted in Montana and Colorado as the "as-constructed" standard for new infrastructure in state right of ways. Recently UESI and the Centre for Advancement of Trenchless Technologies sponsored a talk by Phil Meis, one of the authors of the ASCE 75 standard.

ASCE 75 is applicable to newly installed, repaired, relocated and exposed infrastructure, both below and above ground.  The standard specifies the minimum spatial, 3D geometry, and feature attribute data to be captured for newly installed utilities. Unlike ASCE 38-02 it defines quantitative levels of positional accuracy - for both horizontal and vertical dimensions. It defines a basic set of data that provides a foundation for utility engineering and coordination, network asset management, and the exchange of utility facility information among stakeholders.

Most importantly ASCE 75 is a digital standard, which means that it is consistent with and supports digital construction design standards and delivery practices such as building information modeling (BIM) and virtual design and construction (VDC).

What does it mean for the public right of way owner ?

It makes it possible for the public right of way owner, typically a state Department of Transportation and their designers and contractors, to require advanced 3D digital technologies such as BIM, conflict detection, and reality capture for improved utility coordination with 3rd parties including utility owners. The major benefit is reduced construction risk, time, and costs, and more on-time project completions.

What does it mean for the utility owner ?

For utility owners the benefits of the new standard dwarf the incremental cost.  Standardized recording and retrieval of utility infrastructure data and the ability to exchange information about underground and above-ground utilities among stakeholders provides for enhanced damage prevention and reduced risk to existing utility infrastructure  As a digital standard It enables for more focused and effective utility investigations and conflict assessments. In general it will provide a foundation for more effective utility asset management and more resilient and sustainable infrastructure.

SUE proposed as foundation for best practices for utility coordination on P3 projects

Public infrastructure projects frequently experience delays and cost overruns - often due to underground utilities - but delays and cost overruns are rare on P3 projects. Furthermore because P3 projects include not only the design/build part of the project but also the operate and/or maintain phase, P3s deliver better designed facilities that can be efficiently operated and maintained during the contract term, which can extend from 15 to 30 or more years. To help public-private partnership (P3) project stakeholders develop an efficient and consistent process for coordinating utilities, the Transportation Association of Canada (TAC) has developed a best practices guide specifically targeted on P3 projects. Essential to reducing the risk associated with underground utilities is knowing their accurate, up to date location.  The TAC guide makes subsurface utility engineering (SUE) the foundation for coordinating utilities on P3 public infrastructure projects.

Background

Public infrastructure projects frequently experience delays and cost overruns often due to underground utilities. The reason is that on a typical public construction project the government is responsible for project risks that add time and money to an infrastructure project.

Canada has developed a reputation for successfully delivering infrastructure projects using a public-private partnership (P3) approach. P3s are used to deliver an infrastructure project such as building and expanding roads, bridges, transit systems, and other public infrastructure.

On a P3 project the public sector always owns the infrastructure. The government determines when and where to build the project, its scope, and its budget. A competitive process is used by the government to select a private partner. The private partner designs, builds, finances, maintains and/or operates the public infrastructure. Delays and cost overruns are rare on P3 projects, as this approach allocates risks and responsibilities to the public and private sectors based on their areas of expertise. For example, the public sector bears the risk for changes in laws and regulations and the private partner bears the cost of construction delays. Because P3 projects include not only the design/build part of the project but also the operate and/or maintain phase, P3s deliver better designed facilities that can be efficiently operated and/or maintained during the contract term, which can extend from 15 to 30 or more years.

SUE proposed as foundation for coordinating utilities on P3 projects

There is a trend in legislation and regulation which on one hand may provide strong measures for compelling utilities and other infrastructure owners to improve locating, utility treatments and relocations, on the other provide encouragement for a collaborative approach among utility owners and government agencies which replaces the traditional regulatory mechanisms involving fines and other penalties for noncompliance. On P3 projects in particular the key to successful utility coordination is a team approach, with each member having a role in completing their portion of the project. The players on the team are the project owner, typically a government agency that funds the project; the ROW owner, the government agency responsible for maintaining the public ROW; the Utility Coordinator (UC), responsible for utility coordination on all phases of the project; the designer, who designs the P3 project at different stages ranging from conceptual design through detailed design; and utility agencies, the owners of public or private utility infrastructure who are often also the Project Owner. One of the key challenges for utility agencies is providing accurate records of their existing infrastructure to the Project Owner.

SUE and as-built standards

The foundation for the best practices proposed by TAC for utility coordination is subsurface utility engineering (SUE).  Standard practice for SUE investigations is based on American Society of Civil Engineers (ASCE) 38, first released as ASCE 38-02 but soon to be replaced by ASCE 38-21. The ASCE 38 standard establishes quality levels for underground utility information that all parties can use to evaluate the accuracy and reliability of underground utility location data.

The standards for "as-builts" for newly installed and relocated infrastructure are ASCE 75 in the U.S. and CSA S-250 in Canada.  For example, in Colorado both ASCE 38 and 75 are mandated, which means that every underground and above ground utility segment that's depicted could have either a utility quality level based on ASCE 38 for existing infrastructure or a utility accuracy level from the ASCE 75  "as-constructed" standard for newly installed or relocated utility infrastructure.  In Canada it's a little different. Every utility segment could have either a utility quality level based on ASCE 38 for existing infrastructure or a utility accuracy level from the CSA S-250 standard for newly installed or relocated infrastructure.

Application of SUE over project lifecycle

The TAC guidelines breaks the construction process down into phases: Planning, RFP Document Preparation, In-Market Design, Project Implementation and Post-Construction and identifies the roles and responsibilities of each team member during each phase with respect to utility coordination. The TAC guide describes how SUE practice is allocated over the different phases of the project.

During the Planning Phase the Project Owner is responsible for putting together a base plan of the general construction project area that is adequate for the requirements of utility coordination. The base plan is  forwarded to all impacted Utility Agencies (public and private), with a request for each utility to provide maps of their utility infrastructure based on the Utility Agency’s current records in the proposed project area. This information represents some of the QL-D (from utility records) and QL-C (from site visits) information for the project and is typically of limited quality. It is often  inaccurate, out of date or simply missing, which is frequently he case for abandoned infrastructure. At this stage it is critical that the utility agencies flag high risk utilities such as high pressure transmission lines.  Preliminary SUE investigations, providing QL-B (using remote detection technology) and/or QL-A (potholing), may be completed to validate and improve the quality of the utility information. Based on all of this information the Utility Coordinator creates a preliminary Utility Conflict Matrix that lists potential utility conflicts and relevant information about the utilities identified.  At the completion of the Planning Phase the approximate location of existing utilities and potential future utility infrastructure and possible relocations of high risk infrastructure should be known.

The Request for Proposal (RFP) Documentation Preparation Phase involves preparing the final RFP documents that will be made available to potential bidders. Included in the activities at this stage is the development of a Reference Concept Design (RCD) which may require that additional preliminary SUE investigations be performed to a quality level required for the Project’s In-Market Design Phase. The RCD is used by the Project Owner and Utility Agencies to conduct utility conflict assessments.  If a utility is identified to be in conflict with project works, further SUE QL-A investigations may be required to verify whether it indeed represent a conflict. The RCD design augmented by SUE information plays a significant role in the development of a RCD Utility Conflict Matrix which is a key component of the RFP becausee it provides crucial information about potential utility conflicts to the bidders.

The In-Market Design Phase (or Bid Phase) includes all activities required to deliver a preliminary design which forms the basis for preparing bid estimates.  Starting with the RCD Utility Conflict Matrix, each bidder prepares their own Utility Conflict Matrix based on their RFP submission design.  Knowing the location of existing utility infrastructure is crucial for the bidder to estimate scope of work. To help identify the location of existing utilities – both buried and overhead – the bidders use the information available as background documents provided with the RFP including utility records for private and public utilities, the RCD Utility Matrix, SUE reports provided by the Project Owner, RCD designs, preliminary utility relocation designs from Utility Agencies, and visual inspection and survey information. Since SUE often extends over more than one phase, it is essential to commence SUE investigations early in the Planning Phase to ensure the information is available to the proponents prior to and not beyond the initial In-market Design.  Each bidder is responsible for identifying the location of all existing utilities within the limits of construction, for coordinating any required utility relocations, and all the utility relocation and/or protection work necessary to accommodate utility coordination for the P3 project. During this phase estimating activities may require additional preliminary SUE investigations.  The In-Market Design Phase ends with technical and financial submissions from bidders to the Project Owner. Each submission is evaluated based on a technical and financial assessment and the Project Owner awards the P3 Contract to the successful private partner.

The Project Implementation Phase includes all activities associated with delivering the project from contract award through to completion of construction.

The initial objective of the private partner is to complete the preliminary design to a 30% level. To achieve this requires conducting an additional SUE investigation with the objective of achieving QL-B and QL-A for all underground infrastructure within the project limits.  This is required to ensure that all the required information has been collected to complete the Detailed Design.  This SUE investigation builds on the preliminary SUE information captured during the Planning and In-Market Design Phases.  Based on the complete SUE data the private partner creates a Utility Conflict Matrix that can be maintained and updated regularly to ensure that the latest conflict data is always available to project stakeholders. 

It is also extremely important for each Utility Agency to have access to the latest detailed design and SUE data to enable them complete their relocation designs early in the process. The initial objective of design is to complete the Detailed Design to a level that is sufficient for the utility companies to initiate their respective detailed designs for their relocation work.

After design and during construction, conflicts with unknown utilities may be encountered. It is essential that they be reported immediately to the Utility Coordinator who will initiate a field conflict resolution process. The private partner and the Utility Agencies need to notify the Utility Coordinator at the first indication of a delay to their relocation schedule due to the unknown conflict. The Utility Coordinator is responsible for assessing the impact of the delay on the overall Utility Relocation Coordination Plan and the private partner will follow up to determine the impact on the overall project schedule.

Once relocation construction is completed it is important to ensure that the records submitted for all relocated underground infrastructure are accurate. Utility Agencies are required to prepare “As-Built” drawings to be submitted to the private partner that are compliant with CSA S-250 quality requirements.

Operation and maintenance (O&M) typically represents 80% of the lifetime of an infrastructure facility. In the Post-Construction Phase under a Design, Build, Finance and Operate or Maintain (DBFO or DBFM) P3 model, the private partner is responsible for the operation and/or maintenance of the newly constructed infrastructure for 10 years or more. The O&M responsibility includes all activities necessary to operate or maintain transit facilities, toll roads and other infrastructure.  For civil infrastructure this includes supporting One Call notifications.  An advantage of DBFO and DBFM P3 projects is that it is in the financial interest of the private partner to control O&M costs by optimizing O&M activities.  This includes ensuring that accurate, up to date and complete location data for underground utilities and other infrastructure within the project limits is collected and maintained throughout the project life-cycle.

Application of SUE and as-built standards

During the Planning and In-Market Design (Bid) phases preliminary SUE investigations are conducted to collect and compile underground location data, typically to QL-D and QL-C quality levels. Building on these preliminary SUE investigations, the best practices for P3 projects proposed by the TAC requires the completion of a comprehensive SUE survey that achieves QL-B or QL-A quality levels for all underground infrastructure within the project limits. The TAC guidelines also require that as-builts submitted for all relocated infrastructure be compliant with CSA S-250, which is the Canadian as-built standard, corresponding to ASCE 75, the as-constructed standard in the US.

Conclusion

The guidelines for best practices for utility coordination on P3 projects provided by the Transportation Association of Canada (TAC) makes subsurface utility engineering (SUE) the foundation for reducing the risk associated with underground utilities. The objective of SUE investigations is identifying and determining the accurate, up to date location of underground utilities including abandoned infrastructure. The TAC guidelines also require capturing and maintaining accurate location data for relocated utilities.  Accurate and up to date location data for all underground utilities is critical for controlling costs during the O&M phase, which typically represents 80% of the lifetime of an infrastructure facility.

Revision to Australian AS 5488 Classification of Subsurface Utility Information

Recently national standards relating to underground infrastructure have been revised or are being revised.  These include the US ASCE 38 with a new title Standard Guideline for Investigating and Documenting Existing Utilities, the UK PAS 128 Specification for underground utility detection, verification and location and the Canadian CSA S250 Mapping of underground utility infrastructure. In addition there is a new US standard ASCE 75 Standard Guideline for Recording and Exchanging Utility Infrastructure Data for utility as-constructed data.  Now there will be a revision to the Australian standard AS5488 Classification of Subsurface Utility Information.

The first Australian standard Classification of Subsurface Utility Information (AS5488-2013) was released in 2013. The standard was upgraded in early in 2019 to include a second part covering subsurface utility engineering (SUE). Now a revised AS.5488.1:2019 will be released before January 2022.

National standards and de facto standards relating to underground infrastructure

1983 – Japan Road Information Center (ROADIC)
1998 – Japan Road Management System (ROADIS)
2002 – U.S. ASCE 38-02 Standard Guidelines for the Collection and Depiction of Existing Subsurface Utility Data
2006 – Malaysia Standard Guideline for Underground Utility Mapping
2011 – Canada S250-11 Mapping of underground utility infrastructure
2012 – France Presidential Decree (DT DICT)
2013 – Australia AS 5488-2013 Classification of Subsurface Utility Information (SUI)
2014 – U.K. PAS 128:2014 Specification for underground utility detection, verification and location
2015 - Ecuador NTE INEN 2873
2017 – U.K PAS 256 Buried services – Collection, recording and sharing of location information data
2019 – Australia AS 5488.1:2019 Classification of subsurface utility information
2020 – Canada CSA S250-2020 Mapping of underground utility infrastructure
2021 – U.K. Revised PAS 128
2021 – U.S. ASCE 38-21 Standard Guideline for Investigating and Documenting Existing Utilities
2021 – U.S ASCE 75 Standard Guideline for Recording and Exchanging Utility Infrastructure Data
2022 – Australia Revised AS 5488.1:2019

The ASCE 38-21 underground location quality standard update will be released soon

The grandfather of most quality standards around the globe for the location of underground infrastructure is the American Society of Civil Engineers (ASCE) 38 standard, which was published two decades ago. The original 2002 version of the standard was relatively short, only 20 pages long. Because the practice of subsurface utility engineering (SUE) was new and evolving at that time, the ASCE 38 committee intended to leave the standard very basic to enable it to accommodate new innovations and to allow best practices to emerge. But it also left it open to interpretations that the committee didn't intend. The changes to the ASCE 38 standard that are coming in the update in 2021 are subtle but powerful and primarily intended to clarify the original intent and incorporate the experience of 20 years of practice and innovations to better elucidate those original concepts.

The update to the ASCE 38 standard has been in preparation for a long time, but the ASCE 38 committee wanted to ensure that the update incorporated the very fast changing technology and best practices from around the globe. Important technological advances and advances in best practices were emerging rapidly and frequently and it was a challenge to incorporate these, but now the ASCE 38 committee is confident that they have accommodated the most important of these. In March of this year, the ASCE 38 update achieved a significant milestone by passing unanimously its committee ballot. It was also approved by the three necessary ASCE entities; the standards and publications council, the utility engineering and surveying institute (UESI) board of governors and the parent organization, ASCE codes and standards division, which maintains its standards in accordance with ANSI standards. The draft standard is now with the publications department of ASCE and it's being prepared for a 45 day public comment period. After addressing those public comments, ASCE will prepare the final version of the standard in accordance with the Library of Congress guidelines.  The update will then be published as ASCE 38-21 with a new title Standard Guideline for Investigating and Documenting Existing Utilities.

In contrast to the first version, the latest version of the standard is both prescriptive and a performance standard. It is prescriptive in that it specifies the minimum actions that must be undertaken to achieve (or attempt to achieve) a particular quality level. As a performance standard it describes the professional judgment that needs to be exercised to determine the appropriate timing, sequencing, location and scope of a utility investigative effort to achieve the goal of reducing utility issues during project delivery. A typical project begins with whatever data is available.  In the future that could be a digital twin of the underground. Currently it will include at least past project records in the area of geo-technical information and a topo survey. The engineer develops a scope of work based upon their professional judgment, the client's needs, and the available data. Based on the scope of work, the engineer begins to compile data from various sources. According to the ASCE 38 standard there are four types of inputs; existing records, visibly apparent data at the site, inferred data from geophysical (remote sensing) exploration, and data about exposed utilities. For each utility segment, the professional engineer synthesizes the available inputs and based on the standard assigns a quality level. The quality level isn't about how closely it reflects reality, it's about the certainty with which the location has been determined. An important new concept in the update is guidelines for making professional judgment based upon non-utility information that may infer the presence and location of a non-recorded non-detectable utility such as a plastic waterline without records or trace wire feeding a house.

Related standards

The ASCE 38 standard is intended for subsurface utility engineering surveys (SUE) of existing infrastructure. Other standards, referred to as utility as-built standards, have been developed or are in progress for newly installed infrastructure.

Canada published its utility as-built standard CSA S250 for newly installed utility infrastructure in 2011. It has just been reauthorized and issued as CSA S250:20.

In 2012 at the request of the National Academy of Sciences, ASCE began assembling a committee of broad stakeholders to create the US version of a utility as-built standard. The US standard entitled Standard Guideline for Recording and Exchanging Utility Infrastructure Data is on the same timeline as the update to ASCE 38 and should be published at about the same time. For legal reasons it can't be referred to as a "utility as-built" standard because that terminology conflicts with usage in statutes in several states. As a result it will referred to it as the "utility as-constructed" standard and it will have its own numerical designation distinct from ASCE 38.

Using these two standards in the US, every underground and above ground utility segment that's depicted could have either a utility quality level based on ASCE 38 for existing infrastructure or a utility accuracy level from the "utility as-constructed" standard for newly installed utility infrastructure.  For example, in Colorado both draft standards are mandated.

In Canada it's a little different. Every utility segment could have either a utility quality level based on ASCE 38 for existing infrastructure or a utility accuracy level from the CSA S-250 standard for newly installed infrastructure.

This post is based on Jim Anspach's talk at the Canadian Underground Forum. Jim Anspach is the Chair of ASCE 38. For details on what has changed and what has remained the same in ASCE 38, you can listen to Jim Anspach's talk on the GeoIgnite Youtube channel. 

Two new standards for underground infrastructure imminent from the ASCE

The American Society of Civil Engineers (ASCE) first introduced the ASCE 38-02 Standard Guidelines for the Collection and Depiction of Existing Subsurface Utility Data in 2002 and it has become the model for many underground standards around the world.  Yesterday at the Canadian Underground Forum Jim Anspach, Chair of ASCE 38, mentioned  two new standards that will appear about the same time.  ASCE 38-21Standard Guideline for Investigating and Documenting Existing Utilities is an update to the 38-02 standard reflecting the advance in technologies for detecting, locating and documenting underground utilities and other infrastructure.  The other standard ASCE 75 Standard Guideline for Recording and Exchanging Utility Infrastructure Data, referred to as the utility as-constructed standard, provides guidelines for recording the location of newly installed or relocated underground infrastructure. The current version is currently implemented in Colorado to provide a guideline for new utility infrastructure installations.

Explicit survey accuracies for quality levels C, B and A from the 2018 ASCE White Paper

ASCE 38-21 Standard Guideline for Investigating and Documenting Existing Utilities

Some things remain the same in the latest standard, for example, quality levels A, B, C, D and engineer and utility owner tasks.  But there are important differences.  Perhaps most important is that the standard is more prescriptive, defining specific performance goals that are required.  This is because it was felt that the older standard allowed practitioners to do the minimal and still say that they were ASCE 38-02 compliant. Another big change is explicit survey accuracies for quality levels C, B and A. 3D data has become an essential part of the new standard.