The uncertainty in the location of underground utilities costs the U.S. economy at least $50 billion annually plus injuries and deaths. According to the Pipeline and Hazardous Materials Safety Administration (PHMSA) since 2005, pipeline operators have reported excavation damage as the cause of 1052 incidents, resulting in 48 fatalities and195 injuries requiring hospitalization. But this is not the whole story of injuries and fatalities resulting from damage to underground utilities during construction. A leading cause of highway construction delays is missing or inaccurate information about the location of underground utilities. To address the risk of liabilities associated with unknown or inaccurately located underground utilities, contractors regularly increase bid costs by a minimum of 10-30%. One of the reasons that utility network owners such as gas, electricity, and water distribution companies and telecommunications operators have not been motivated to improve the quality of the location information about their infrastructure is the nature of state regulation of liabilities in the construction industry. Liabilities in this context refers to who is responsible when an underground cable or pipe is hit during an excavation. The North American regulatory framework is in contrast with the French model which is designed to result over time in improved information about the location of the nation's underground infrastructure.
As an example of a simple regulatory model relating to underground infrastructure, I remember several years ago at a GITA ANZ event in Brisbane hearing about a proposed liability model for Queensland water infrastructure. It was very simple. When a utility or a contractor employed by a utility completes a job installing or maintaining underground facilities, they are required to submit accurate as-builts. The next time there is an excavation in the same area, those as-builts are provided to the excavator. If there is a utility hit or strike, the liabilities would work as follows: if the as-builts were accurate, then the hit is the excavator's responsibility, if the as-builts were not accurate, it is the utility's or the utility's contractor's responsibility. In this example there is a strong motivation for the utility operator to ensure that their records record the location of their underground facilities accurately. Their contractual arrangements with their contractors would pass this liability on so that in the case of damage, whoever was responsible for the as-builts shared responsibility for the damage and the motivation to ensure they were accurate.
Regulation of liabilities in North America
In North America regulation works in a very different way. I'll take Florida as an example. The Underground Facility Damage Prevention and Safety Act enacted in 2017 by the Florida legislature is typical of the legislation creating state one-call or call-before-you centers. It mandates that every organization with underground infrastructure is required to be a member of the state one-call center, which is supported by members. Each utility has to provide information to the center about the service area where they might have underground facilities. They are also required to provide underground locate services. This can be quite expensive because it typically involves dedicated staff and an investment in underground detection equipment and vehicles.
If an excavator does not call the state one-call center and hits a utility, the excavator is liable for all costs, therefore excavators for industrial, commercial and public (but often not residential) construction projects generally contact the one-call center prior to digging. The excavator provides the rough location and depth of the proposed excavation and when they plan to begin work. Since the one-call center does not maintain maps of underground infrastructure, when an excavator contacts them, they contact all utilities whose service territories overlap the planned excavation and pass on the information about the proposed excavation.
In Florida the utility operator has two days to come to an excavation site to mark using stakes, paint or flags where they believe their facilities are. The Florida act stipulates that these markings identify a corridor 4 feet wide within which a utility cable or pipe is expected to be found and that they conform to a standard for colour code for markings. The law also provides an option for a utility operator to state that it believes it has facilities in the area but is unable to identify where they are. This option is only available for abandoned facilities or for facilities that are not detectable with the available technology.
Typically each utility and telecom operator contacted will dispatch locate staff equipped with current as-builts, electromagnetic wands and increasingly with ground penetrating radar to detect and mark where their networks traverse the site. After all the network operators with facilities in the areas have done this, the excavator is free to begin excavation. If a network operator has stated that it can't identify the location of its facilities, the Florida act requires the excavator to use underground detection tools to try to identify any underground facilities. The excavator is free to dig outside the marked utility corridors. To dig within the corridors, the Florida act stipulates that soft digging techniques must be used.
Liabilities work as follows:
- If after the network operators identify the location of underground facilities, an excavator causes damage, the excavator is liable for the total sum of the losses to all parties involved to a maximum of $500,000 per underground network.
- If a network operator does not mark the location of its facilities after being contacted by the One-Call system and an excavator damages the underground network, the excavator is not liable for the damage and the network operator is liable for any any injury to a person or to equipment to a maximum of $500,000.
- If the network operator isn't able to identify the location of its facilities in the excavation area, the excavator is not liable for any damages that might occur.
But there is a proviso on this: An excavator must excavate in a "careful and prudent manner, based on accepted engineering and construction practices, and it does not excuse the excavator from liability for any damage or injury resulting from any excavation or demolition." Furthermore, if the network operator is unable to identify the location of its facilities in the excavation area, the act stipulates that the excavator must use subsurface detection tools to try to identify the location of the infrastructure.
At a high level the liabilities are pretty straightforward, but in practice there is plenty of room for litigation. A recent example of what can happen when unknown utilities are encountered during construction is the 405 Freeway widening project in Los Angeles where workers had to remove nine miles of unexpected utility lines which contributed to delaying the project a year behind schedule and resulted in a $400 million lawsuit.
The other important aspect of this legislation is that it does not require the information discovered about underground utilities to be shared. It is not the responsibility of the one-call center itself to manage this type of information. The act does not mention maps, paper or digital, to be provided by the network operators nor does it require utility location information discovered by the excavator to be shared with the network operators. Over time there is little in this act that would lead to an improved 3D map of underground infrastructure.
In addition to improved safety to the public and construction workers, there is a financial motivation for a utility or telcom to improve the quality of its mapping of it underground infrastructure. A not insignificant cost incurred by a utility supporting this liability structure is the maintenance of a fleet of cable locate vans, equipment and staff. A utility can reap significant cost savings by reducing the size of this fleet by improving the quality and timelines of the information about the location of their underground infrastructure. For example, I worked with a power utility in Calgary that had over twenty vans dedicated to cable locates. Calgary, in a very forward looking move, had passed an ordinance that required that all utilities and telcos operating within city limits share maps of their underground networks as part of Joint Utility Mapping Partnership (JUMP). The maps had to be submitted in digital form, DGN files at the time. Under the impetus of the city ordinance, the utility I worked with decided to change their facilities records workflow to improve the quality and timelines of their data so that the maps they made available through JUMP were accurate and uptodate. To do this required changing the data flow from network engineering to their GIS. All of their engineering data was stored in a spatially-enabled relational database which enabled them to shorten the cycle from engineering to GIS and ensure that records backlogs were very short, on the order of a day. One of the important benefits of JUMP and the improved data workflow was that the utility reduced its fleet of more than 20 locate vehicles to two, freeing up staff for other activities and saving several hundred thousand dollars annually.
The North American model also results in unnecessary utility relocations. For example, in the traditional approach to highway design, the designer ignores utilities during design. After design and right-of-way acquisition, the one-call center would be notified and the affected utilities would mark the location of their utilities. If utilities conflict with the design, they would have to be relocated. As a result utilities are routinely relocated, often at great expense and often unnecessarily. A better approach is to design the highway in a way that takes into account where utilities are located to minimize relocations. But this requires accurate maps of underground utilities during the planning and design phase, not just prior to construction.
In spite of these motivations for better information about the location of underground infrastructure, the liability structure in North America, which effectively limits risk for excavators and operators, has historically not provided a strong motivation for utility or telecom operators to implement procedures to improve the quality of this information. The North American underground locate industry is estimated to be worth $10 billion annually. If the information about the location of underground utilities captured by this industry were shared, it would be expected that our knowledge about the location of underground infrastructure would gradually improve, the risk to the public and workers and the drag on the economy associated with underground utility hits would decrease, the cost of utility locates to utilities and telecoms would decrease, and fewer utility relocations would be required during construction.
Regulation in France
It is interesting to contrast this legal structure with that in France as laid out in the 2012 Presidential Decree on critical infrastructure. Project managers of proposed construction projects are required to send a statement of the proposed work including a polygon delineating the area affected to the operators of all utility networks operating in the area. In return network operators must provide to the project manager maps of their underground networks in the area indicating the accuracy of the geographical location of different structures of their networks classified according to three accuracy classes.
- Class A: if the maximum uncertainty of location indicated by the utility operator is less than or equal to 40 cm
- Class B: if the maximum uncertainty of location indicated by the utility operator is greater than that for Class A and less than or equal to 1.5 meters
- Class C: if the maximum uncertainty of location indicated by the utility operator is greater than 1.5 meters , or if the operator is not able to provide the location.
The Decree states that uncertainty in the geographical location of a structure is considered likely to jeopardize the construction project or significantly impact the technical or financial conditions of its implementation when the geolocation of the structure is classified in accuracy classes B or C. If a facility is classified as B or C, the excavator will have to carry out further investigation to locate it. The Decree specifies that the cost of this further investigation will be shared between the excavator and the network operator according to the following rules:
- The excavator assumes the entire cost when the structures are assigned by the operator to accuracy class B and further investigation reveals that the actual classification is found to be Class B or Class A
- Half of the cost of the investigation is to be borne by the operator when the structures are assigned by the operator to accuracy class C;
- All of the cost is to be borne by the operator when the structures have been assigned by the operator to accuracy class B and when the result of further investigation reveals that the actual classification is accuracy class C
The decree requires that any improved location information discovered by the excavator must be shared with the network operator. As a result over time it would be expected that the number of facilities classified as B or C would decline. If many of an operator's facilities were classified as C or B the financial outlay for sharing the cost of excavators to locate underground utilities for a large number of construction projects could become substantial. This would be expected to provide a strong motivation for network operators to improve the quality of the location information about their facilities.
Another important advantage of the French system is that it specifies maps which means that information about underground utilities would be available to developers during planning and design.
Accurate information about underground infrastructure can reduce the delay between notifying the one call center and beginning excavation from days to minutes. It also means that utility location information is available during planning and design. I have blogged about the Dutch KLIC system. In Belgium there is a similar system called KLIP. In both countries, it is possible to logon to an online system, provide a digital polygon of the proposed excavation area and download a map of all underground utilities in the area within minutes.
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